@article{AlbannaConzenWeissetal.2016, author = {Albanna, W. and Conzen, C. and Weiss, M. and Clusmann, H. and Fuest, M. and Mueller, M. and Brockmann, M.A. and Vilser, W. and Schmidt-Trucks{\"a}ss, A. and Hoellig, A. and Seiz, M. and Thom{\´e}, C. and Kotliar, Konstantin and Schubert, G.A.}, title = {Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {7}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0158781}, pages = {13 Seiten}, year = {2016}, abstract = {Background Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH. Methods In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2-14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling. Results Image quality was satisfactory in the majority of cases (93.3\%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion. Conclusion RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort.}, language = {en} } @article{AlbannaConzenWeissetal.2021, author = {Albanna, Walid and Conzen, Catharina and Weiss, Miriam and Seyfried, Katharina and Kotliar, Konstantin and Schmidt, Tobias Philip and Kuerten, David and Hescheler, J{\"u}rgen and Bruecken, Anne and Schmidt-Trucks{\"a}ss, Arno and Neumaier, Felix and Wiesmann, Martin and Clusmann, Hans and Schubert, Gerrit Alexander}, title = {Non-invasive assessment of neurovascular coupling after aneurysmal subarachnoid hemorrhage: a prospective observational trial using retinal vessel analysis}, series = {Frontiers in Neurology}, volume = {12}, journal = {Frontiers in Neurology}, number = {12}, issn = {1664-2295}, doi = {10.3389/fneur.2021.690183}, pages = {1 -- 15}, year = {2021}, abstract = {Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus.}, language = {en} } @article{AlbannaKotliarLuekeetal.2018, author = {Albanna, Walid and Kotliar, Konstantin and L{\"u}ke, Jan Niklas and Alpdogan, Serdar and Conzen, Catharina and Lindauer, Ute and Clusmann, Hans and Hescheler, J{\"u}rgen and Vilser, Walthard and Schneider, Toni and Schubert, Gerrit Alexander}, title = {Non-invasive evaluation of neurovascular coupling in the murine retina by dynamic retinal vessel analysis}, series = {Plos one}, volume = {13}, journal = {Plos one}, number = {10}, publisher = {PLOS}, address = {San Francisco}, doi = {10.1371/journal.pone.0204689}, pages = {e0204689}, year = {2018}, abstract = {Background Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC. Methods A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed. Results A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001). Conclusions To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals.}, language = {en} } @article{AlbannaLuekeSjapicetal.2017, author = {Albanna, Walid and Lueke, Jan Niklas and Sjapic, Volha and Kotliar, Konstantin and Hescheler, J{\"u}rgen and Clusmann, Hans and Sjapic, Sergej and Alpdogan, Serdan and Schneider, Toni and Schubert, Gerrit Alexander and Neumaier, Felix}, title = {Electroretinographic Assessment of Inner Retinal Signaling in the Isolated and Superfused Murine Retina}, series = {Current Eye Research}, journal = {Current Eye Research}, number = {Article in press}, publisher = {Taylor \& Francis}, address = {London}, issn = {1460-2202}, doi = {10.1080/02713683.2017.1339807}, pages = {1 -- 9}, year = {2017}, language = {en} } @article{AlbannaLuekeSchubertetal.2019, author = {Albanna, Walid and L{\"u}ke, Jan Niklas and Schubert, Gerrit Alexander and Dibu{\´e}-Adjei, Maxine and Kotliar, Konstantin and Hescheler, J{\"u}rgen and Clusmann, Hans and Steiger, Hans-Jakob and H{\"a}nggi, Daniel and Kamp, Marcel A. and Schneider, Toni and Neumaier, Felix}, title = {Modulation of Ca v 2.3 channels by unconjugated bilirubin (UCB) - Candidate mechanism for UCB-induced neuromodulation and neurotoxicity}, series = {Molecular and Cellular Neuroscience}, volume = {96}, journal = {Molecular and Cellular Neuroscience}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1044-7431}, doi = {10.1016/j.mcn.2019.03.003}, pages = {35 -- 46}, year = {2019}, language = {en} } @phdthesis{Albracht2010, author = {Albracht, Kirsten}, title = {Influence of mechanical properties of the leg extensor muscletendon units on running economy}, publisher = {Deutsche Sporthochschule K{\"o}ln}, address = {K{\"o}ln}, pages = {X, 1221 Bl. : graph. Darst.}, year = {2010}, language = {en} } @article{AlbrachtArampatzisBaltzopoulos2008, author = {Albracht, Kirsten and Arampatzis, A. and Baltzopoulos, V.}, title = {Assessment of muscle volume and physiological cross-sectional area of the human triceps surae muscle in vivo}, series = {Journal of Biomechanics}, volume = {41}, journal = {Journal of Biomechanics}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2008.04.020}, pages = {2211 -- 2218}, year = {2008}, language = {en} } @article{AlbrachtArampatzis2013, author = {Albracht, Kirsten and Arampatzis, Adamantios}, title = {Exercise-induced changes in triceps surae tendon stiffness and muscle strength affect running economy in humans}, series = {European Journal of Applied Physiology}, volume = {113}, journal = {European Journal of Applied Physiology}, number = {6}, publisher = {Springer}, address = {Berlin}, issn = {1439-6327}, doi = {10.1007/s00421-012-2585-4}, pages = {1605 -- 1615}, year = {2013}, language = {en} } @article{AlbrachtArampatzis2006, author = {Albracht, Kirsten and Arampatzis, Adamantios}, title = {Influence of the mechanical properties of the muscle-tendon unit on force generation in runners with different running economy}, series = {Biological Cybernetics}, volume = {95}, journal = {Biological Cybernetics}, number = {1}, issn = {1432-0770}, doi = {10.1007/s00422-006-0070-z}, pages = {87 -- 96}, year = {2006}, language = {en} } @article{AlexyukBogoyavlenskiyAlexyuketal.2021, author = {Alexyuk, Madina and Bogoyavlenskiy, Andrey and Alexyuk, Pavel and Moldakhanov, Yergali and Berezin, Vladimir and Digel, Ilya}, title = {Epipelagic microbiome of the Small Aral Sea: Metagenomic structure and ecological diversity}, series = {MicrobiologyOpen}, volume = {10}, journal = {MicrobiologyOpen}, number = {1}, publisher = {Wiley}, address = {Weinheim}, issn = {2045-8827}, doi = {10.1002/mbo3.1142}, pages = {1 -- 10}, year = {2021}, abstract = {Microbial diversity studies regarding the aquatic communities that experienced or are experiencing environmental problems are essential for the comprehension of the remediation dynamics. In this pilot study, we present data on the phylogenetic and ecological structure of microorganisms from epipelagic water samples collected in the Small Aral Sea (SAS). The raw data were generated by massive parallel sequencing using the shotgun approach. As expected, most of the identified DNA sequences belonged to Terrabacteria and Actinobacteria (40\% and 37\% of the total reads, respectively). The occurrence of Deinococcus-Thermus, Armatimonadetes, Chloroflexi in the epipelagic SAS waters was less anticipated. Surprising was also the detection of sequences, which are characteristic for strict anaerobes—Ignavibacteria, hydrogen-oxidizing bacteria, and archaeal methanogenic species. We suppose that the observed very broad range of phylogenetic and ecological features displayed by the SAS reads demonstrates a more intensive mixing of water masses originating from diverse ecological niches of the Aral-Syr Darya River basin than presumed before.}, language = {en} } @article{AlnemerKotliarNeuhausetal.2023, author = {Alnemer, Momin Sami Mohammad and Kotliar, Konstantin and Neuhaus, Valentin and Pape, Hans-Christoph and Ciritsis, Bernhard D.}, title = {Cost-effectiveness analysis of surgical proximal femur fracture prevention in elderly: a Markov cohort simulation model}, series = {Cost Effectiveness and Resource Allocation}, journal = {Cost Effectiveness and Resource Allocation}, number = {21, Article number: 77}, publisher = {Springer Nature}, issn = {1478-7547}, doi = {10.1186/s12962-023-00482-4}, pages = {12 Seiten}, year = {2023}, abstract = {Background Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices. Methods This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare \& Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10\% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results. Results With a 10\% fracture risk reduction, model A costs between \$8,850 and \$46,940 per quality-adjusted life-year (\$/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8\% is needed for prophylaxis to be definitely cost-effective. The cost-effectiveness at the secondary prevention level was most sensitive to the cost of the contralateral side's prophylaxis, the patient's age, and fracture treatment cost. For high-risk patients with no fracture history, the cost-effectiveness of a preventive strategy depends on their risk profile. In the baseline analysis, the incremental cost-effectiveness ratio at the primary prevention level varied between \$11,000/QALY and \$74,000/QALY, which is below the defined willingness to pay threshold. Conclusion Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks.}, language = {en} } @article{AminTemizArtmannArtmannetal.2009, author = {Amin, Rashid and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard and Lazarovici, Philip and Lelkes, Peter I.}, title = {Permeability of an In Vitro Model of Blood Brain Barrier (BBB)}, series = {13th International Conference on Biomedical Engineering / Lim, Chwee Teck [Ed.]}, journal = {13th International Conference on Biomedical Engineering / Lim, Chwee Teck [Ed.]}, isbn = {978-3-540-92841-6}, pages = {81 -- 84}, year = {2009}, language = {en} } @article{AndingTabazaStaatetal.2013, author = {Anding, Ralf and Tabaza, Ruth and Staat, Manfred and Trenz, Eva and Lohmann, Philipp and Klinge, Uwe and Kirschner-Hermanns, Ruth}, title = {Introducing a method of in vitro testing of different anchoring systems used for female incontinence and prolapse surgery}, series = {BioMed research international}, volume = {Vol. 2013}, journal = {BioMed research international}, issn = {1110-7251 (E-Journal); 2314-6141 (E-Journal); 1110-7243 (Print); 2314-6133 (Print)}, pages = {Article ID 401417}, year = {2013}, language = {en} } @article{AngermannGuenthnerHanssenetal.2022, author = {Angermann, Susanne and G{\"u}nthner, Roman and Hanssen, Henner and Lorenz, Georg and Braunisch, Matthias C. and Steubl, Dominik and Matschkal, Julia and Kemmner, Stephan and Hausinger, Renate and Block, Zenonas and Haller, Bernhard and Heemann, Uwe and Kotliar, Konstantin and Grimmer, Timo and Schmaderer, Christoph}, title = {Cognitive impairment and microvascular function in end-stage renal disease}, series = {International Journal of Methods in Psychiatric Research (MPR)}, volume = {31}, journal = {International Journal of Methods in Psychiatric Research (MPR)}, number = {2}, publisher = {Wiley}, issn = {1049-8931 (Print)}, doi = {10.1002/mpr.1909}, pages = {1 -- 10}, year = {2022}, abstract = {Objective Hemodialysis patients show an approximately threefold higher prevalence of cognitive impairment compared to the age-matched general population. Impaired microcirculatory function is one of the assumed causes. Dynamic retinal vessel analysis is a quantitative method for measuring neurovascular coupling and microvascular endothelial function. We hypothesize that cognitive impairment is associated with altered microcirculation of retinal vessels. Methods 152 chronic hemodialysis patients underwent cognitive testing using the Montreal Cognitive Assessment. Retinal microcirculation was assessed by Dynamic Retinal Vessel Analysis, which carries out an examination recording retinal vessels' reaction to a flicker light stimulus under standardized conditions. Results In unadjusted as well as in adjusted linear regression analyses a significant association between the visuospatial executive function domain score of the Montreal Cognitive Assessment and the maximum arteriolar dilation as response of retinal arterioles to the flicker light stimulation was obtained. Conclusion This is the first study determining retinal microvascular function as surrogate for cerebral microvascular function and cognition in hemodialysis patients. The relationship between impairment in executive function and reduced arteriolar reaction to flicker light stimulation supports the involvement of cerebral small vessel disease as contributing factor for the development of cognitive impairment in this patient population and might be a target for noninvasive disease monitoring and therapeutic intervention.}, language = {en} } @article{ArampatzisKaramanidisAlbracht2007, author = {Arampatzis, Adamantios and Karamanidis, Kiros and Albracht, Kirsten}, title = {Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude}, series = {Journal of Experimental Biology}, volume = {210}, journal = {Journal of Experimental Biology}, number = {15}, issn = {0022-0949}, doi = {10.1242/jeb.003814}, pages = {2743 -- 2753}, year = {2007}, language = {en} } @article{ArampatzisKaramanidisMademlietal.2009, author = {Arampatzis, Adamantios and Karamanidis, Kiros and Mademli, Lida and Albracht, Kirsten}, title = {Plasticity of the human tendon to short and long-term mechanical loading}, series = {Exercise and Sport Sciences Reviews}, volume = {37}, journal = {Exercise and Sport Sciences Reviews}, number = {2}, issn = {1538-3008}, doi = {10.1097/JES.0b013e31819c2e1d}, pages = {66 -- 72}, year = {2009}, language = {en} } @article{ArampatzisPeperBierbaumetal.2010, author = {Arampatzis, Adamantios and Peper, Andreas and Bierbaum, Stefanie and Albracht, Kirsten}, title = {Plasticity of human Achilles tendon mechanical and morphological properties in response to cyclic strain}, series = {Journal of Biomechanics}, volume = {43}, journal = {Journal of Biomechanics}, number = {16}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2010.08.014}, pages = {3073 -- 3079}, year = {2010}, abstract = {The purpose of the current study in combination with our previous published data (Arampatzis et al., 2007) was to examine the effects of a controlled modulation of strain magnitude and strain frequency applied to the Achilles tendon on the plasticity of tendon mechanical and morphological properties. Eleven male adults (23.9±2.2 yr) participated in the study. The participants exercised one leg at low magnitude tendon strain (2.97±0.47\%), and the other leg at high tendon strain magnitude (4.72±1.08\%) of similar frequency (0.5 Hz, 1 s loading, 1 s relaxation) and exercise volume (integral of the plantar flexion moment over time) for 14 weeks, 4 days per week, 5 sets per session. The exercise volume was similar to the intervention of our earlier study (0.17 Hz frequency; 3 s loading, 3 s relaxation) allowing a direct comparison of the results. Before and after the intervention ankle joint moment has been measured by a dynamometer, tendon-aponeurosis elongation by ultrasound and cross-sectional area of the Achilles tendon by magnet resonance images (MRI). We found a decrease in strain at a given tendon force, an increase in tendon-aponeurosis stiffness and tendon elastic modulus of the Achilles tendon only in the leg exercised at high strain magnitude. The cross-sectional area (CSA) of the Achilles tendon did not show any statistically significant (P>0.05) differences to the pre-exercise values in both legs. The results indicate a superior improvement in tendon properties (stiffness, elastic modulus and CSA) at the low frequency (0.17 Hz) compared to the high strain frequency (0.5 Hz) protocol. These findings provide evidence that the strain magnitude applied to the Achilles tendon should exceed the value, which occurs during habitual activities to trigger adaptational effects and that higher tendon strain duration per contraction leads to superior tendon adaptational responses.}, language = {en} } @inproceedings{ArinkinDigel2009, author = {Arinkin, Vladimir and Digel, Ilya}, title = {Water bridge phenomenon : [abstract]}, year = {2009}, abstract = {One of interesting but not well known water properties is related to appearance of highly ordered structures in response to strong electrical field. In 1893 Sir William Armstrong placed a cotton thread between two wine glasses filled with chemically pure water. When high DC voltage was applied between the glasses, a connection consisting of water formed, producing a "water bridge"}, subject = {Hydrodynamik}, language = {en} } @article{ArinkinDigelPorstetal.2014, author = {Arinkin, Vladimir and Digel, Ilya and Porst, Dariusz and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard}, title = {Phenotyping date palm varieties via leaflet cross-sectional imaging and artificial neural network application}, series = {BMC bioinformatics}, volume = {15}, journal = {BMC bioinformatics}, number = {55}, issn = {1471-2105}, doi = {10.1186/1471-2105-15-55}, pages = {1 -- 8}, year = {2014}, abstract = {Background True date palms (Phoenix dactylifera L.) are impressive trees and have served as an indispensable source of food for mankind in tropical and subtropical countries for centuries. The aim of this study is to differentiate date palm tree varieties by analysing leaflet cross sections with technical/optical methods and artificial neural networks (ANN). Results Fluorescence microscopy images of leaflet cross sections have been taken from a set of five date palm tree cultivars (Hewlat al Jouf, Khlas, Nabot Soltan, Shishi, Um Raheem). After features extraction from images, the obtained data have been fed in a multilayer perceptron ANN with backpropagation learning algorithm. Conclusions Overall, an accurate result in prediction and differentiation of date palm tree cultivars was achieved with average prediction in tenfold cross-validation is 89.1\% and reached 100\% in one of the best ANN.}, language = {en} } @book{Artmann2008, author = {Artmann, Gerhard}, title = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-75408-4}, year = {2008}, language = {en} } @book{Artmann2011, author = {Artmann, Gerhard}, title = {Stem cell engineering : principles and applications / Gerhard M. Artmann ... eds.}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-642-11864-7}, pages = {XLI, 541 S. : Ill., graph. Darst.}, year = {2011}, language = {en} } @article{ArtmannBurnsCanavesetal.2004, author = {Artmann, Gerhard and Burns, Laura and Canaves, Jaume M. and Temiz Artmann, Ayseg{\"u}l}, title = {Circular dichroism spectra of human hemoglobin reveal a reversible structural transition at body temperature}, series = {European Biophysics Journal. 33 (2004), H. 6}, journal = {European Biophysics Journal. 33 (2004), H. 6}, isbn = {1432-1017}, pages = {490 -- 496}, year = {2004}, language = {en} } @article{ArtmannDigelLinderetal.2008, author = {Artmann, Gerhard and Digel, Ilya and Linder, Peter and Porst, Dariusz}, title = {Mechanism of haemoglobin sensing body temperature}, series = {Tissue Engineering Part A. 14 (2008), H. 5}, journal = {Tissue Engineering Part A. 14 (2008), H. 5}, isbn = {1937-3341}, pages = {754 -- 754}, year = {2008}, language = {en} } @inproceedings{ArtmannDigelLinderetal.2011, author = {Artmann, Gerhard and Digel, Ilya and Linder, Peter and Temiz Artmann, Ayseg{\"u}l}, title = {Biophysical and Engineering Contributions to Plant Research}, year = {2011}, abstract = {Tests with palm tree leaves have just started yet and scan data are in the process to be analyzed. The final goal of future project for palm tree gender and species recognition will be to develop optical scanning technology to be applied to date palm tree leaves for in-situ screening purposes. Depending on the software used and the particular requirements of the users the technology potentially shall be able to identify palm tree diseases, palm tree gender, and species of young date palm trees by scanning leaves.}, subject = {Pflanzenphysiologie}, language = {en} } @article{ArtmannDigelZerlinetal.2009, author = {Artmann, Gerhard and Digel, Ilya and Zerlin, Kay and Maggakis-Kelemen, Christina and Linder, Peter and Porst, Dariusz and Kayser, Peter and Stadler, David and Dikta, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Hemoglobin senses body temperature}, series = {European Biophysics Journal}, volume = {38}, journal = {European Biophysics Journal}, number = {5}, isbn = {0175-7571}, pages = {589 -- 600}, year = {2009}, language = {en} } @article{ArtmannHueckRossiteretal.2008, author = {Artmann, Gerhard and Hueck, Isgard S. and Rossiter, Katharine and Schmid-Sch{\"o}nbein, Geert W.}, title = {Fluid Shear Attenuates Endothelial Pseudopodia Formation into the Capillary Lumen / Hueck, Isgard S. ; Rossiter, Katharine ; Artman, Gerhard M. ; Schmid-Sch{\"o}nbein, Geert W.}, series = {Microcirculation. 15 (2008), H. 6}, journal = {Microcirculation. 15 (2008), H. 6}, isbn = {1549-8719}, pages = {531 -- 542}, year = {2008}, language = {en} } @misc{ArtmannLinderBayeretal.2017, author = {Artmann, Gerhard and Linder, Peter and Bayer, Robin and Gossmann, Matthias}, title = {Celldrum electrode arrangement for measuring mechanical stress [Patent of invention]}, publisher = {WIPO}, address = {Geneva}, pages = {18 Seiten}, year = {2017}, abstract = {The invention pertains to a CellDrum electrode arrangement for measuring mechanical stress, comprising a mechanical holder (1 ) and a non-conductive membrane (4), whereby the membrane (4) is at least partially fixed at its circumference to the mechanical holder (1), keeping it in place when the membrane (4) may bend due to forces acting on the membrane (4), the mechanical holder (1) and the membrane (4) forming a container, whereby the membrane (1) within the container comprises an cell- membrane compound layer or biological material (3) adhered to the deformable membrane 4 which in response to stimulation by an agent may exert mechanical stress to the membrane (4) such that the membrane bending stage changes whereby the container may be filled with an electrolyte, whereby an electric contact (2) is arranged allowing to contact said electrolyte when filled into to the container, whereby within a predefined geometry to the fixing of the membrane (4) an electrode (7) is arranged, whereby the electrode (7) is electrically insulated with respect to the electric contact (2) as well as said electrolyte, whereby mechanical stress due to an agent may be measured as a change in capacitance.}, language = {en} } @incollection{ArtmannMeruvuKizildagetal.2018, author = {Artmann, Gerhard and Meruvu, Haritha and Kizildag, Sefa and Temiz Artmann, Ayseg{\"u}l}, title = {Functional Toxicology and Pharmacology Test of Cell Induced Mechanical Tensile Stress in 2D and 3D Tissue Cultures}, series = {Biological, Physical and Technical Basics of Cell Engineering}, booktitle = {Biological, Physical and Technical Basics of Cell Engineering}, editor = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7904-7}, doi = {10.1007/978-981-10-7904-7_7}, pages = {157 -- 192}, year = {2018}, abstract = {Mechanical forces/tensile stresses are critical determinants of cellular growth, differentiation and migration patterns in health and disease. The innovative "CellDrum technology" was designed for measuring mechanical tensile stress of cultured cell monolayers/thin tissue constructs routinely. These are cultivated on very thin silicone membranes in the so-called CellDrum. The cell layers adhere firmly to the membrane and thus transmit the cell forces generated. A CellDrum consists of a cylinder which is sealed from below with a 4 μm thick, biocompatible, functionalized silicone membrane. The weight of cell culture medium bulbs the membrane out downwards. Membrane indentation is measured. When cells contract due to drug action, membrane, cells and medium are lifted upwards. The induced indentation changes allow for lateral drug induced mechanical tension quantification of the micro-tissues. With hiPS-induced (human) Cardiomyocytes (CM) the CellDrum opens new perspectives of individualized cardiac drug testing. Here, monolayers of self-beating hiPS-CMs were grown in CellDrums. Rhythmic contractions of the hiPS-cells induce membrane up-and-down deflections. The recorded cycles allow for single beat amplitude, single beat duration, integration of the single beat amplitude over the beat time and frequency analysis. Dose effects of agonists and antagonists acting on Ca2+ channels were sensitively and highly reproducibly observed. Data were consistent with published reference data as far as they were available. The combination of the CellDrum technology with hiPS-Cardiomyocytes offers a fast, facile and precise system for pharmacological and toxicological studies. It allows new preclinical basic as well as applied research in pharmacolgy and toxicology.}, language = {en} } @inproceedings{ArtmannStadlerEmbsetal.2010, author = {Artmann, Gerhard and Stadler, Andreas M. and Embs, Jan P. and Zaccai, Giuseppe and B{\"u}ldt, Georg and Digel, Ilya and Temiz Artmann, Ayseg{\"u}l}, title = {The crucial role of water in a phase transition of hemoglobin at body temperature : [abstract]}, year = {2010}, abstract = {The observation of a temperature transition of hemoglobin occurring at a critical temperature close to body temperature}, subject = {H{\"a}moglobin}, language = {en} } @book{ArtmannTemizArtmannZhubanovaetal.2018, author = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, title = {Biological, physical and technical basics of cell engineering}, editor = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7903-0}, pages = {xxiv, 481 Seiten ; Illustrationen, Diagramme}, year = {2018}, language = {en} } @article{ArtmannTrzewikAtes2002, author = {Artmann, Gerhard and Trzewik, J{\"u}rgen and Ates, M.}, title = {A novel method to quantify mechanical tension in cell monolayers. Trzewik, J{\"u}rgen; Ates, M., Artmann, Gerhard Michael}, series = {Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1}, journal = {Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1}, isbn = {0013-5585}, pages = {379 -- 381}, year = {2002}, language = {en} } @article{ArtmannZerlinDigel2008, author = {Artmann, Gerhard and Zerlin, Kay and Digel, Ilya}, title = {Hemoglobin Senses Body Temperature}, series = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, journal = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-75408-4}, pages = {415 -- 447}, year = {2008}, language = {en} } @article{ArtmannZerlinDigeletal.2007, author = {Artmann, Gerhard and Zerlin, Kay and Digel, Ilya and Stadler, Andreas M.}, title = {Physical discontinuities at body temperature in human red blood cells / Artmann, GM ; Zerlin, K ; Digel, I ; Stadler, A ; Zaccai, G ; Temiz, AA}, series = {Tissue Engineering. 13 (2007), H. 7}, journal = {Tissue Engineering. 13 (2007), H. 7}, isbn = {1076-3279}, pages = {1778 -- 1778}, year = {2007}, language = {en} } @article{ArtmannZhouStacheBuettneretal.2002, author = {Artmann, Gerhard and Zhou-Stache, J. and Buettner, R. and Mittermayer, C. [u.a.]}, title = {Inhibition of TNF-alpha induced cell death in HUVEC and Jurkat cells by protocatechuic acid. Zhou-Stache, J.; Buettner, R.; Artmann, Gerhard Michael; Mittermayer, C.; Bosserhoff, A. K.}, series = {Medical and Biological Engineering and Computing. 40 (2002), H. 6}, journal = {Medical and Biological Engineering and Computing. 40 (2002), H. 6}, isbn = {0140-0118}, pages = {698 -- 703}, year = {2002}, language = {en} } @article{AttarMerkKotliaretal.2019, author = {Attar, Mandana Hossein Zadeh and Merk, Hans F. and Kotliar, Konstantin and Wurpts, Gerda and R{\"o}seler, Stefani and Moll-Slodowy, Silke and Plange, Johann and Baron, Jens Malte and Balakirski, Galina}, title = {The CD63 basophil activation test as a diagnostic tool for assessing autoimmunity in patients with chronic spontaneous urticaria}, series = {European Journal of Dermatology}, volume = {29}, journal = {European Journal of Dermatology}, number = {6}, doi = {10.1684/ejd.2019.3680}, pages = {614 -- 618}, year = {2019}, language = {en} } @inproceedings{AzarDigel2019, author = {Azar, Fouad and Digel, Ilya}, title = {Utilization of fluorescence spectroscopy and neural networks in clinical analysis}, series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, editor = {Staat, Manfred and Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-22-6}, doi = {10.17185/duepublico/48750}, pages = {40 -- 41}, year = {2019}, abstract = {Fluorescence topography of human urine in combination with learning algorithms can provide a variant pattern recognition method in analytical clinical chemistry and, eventually, diagnosis.}, language = {en} } @incollection{AzatKerimkulovaMansurovetal.2020, author = {Azat, Seitkhan and Kerimkulova, Almagul R. and Mansurov, Zulkhair A. and Adekenov, Sergazy and Artmann, Gerhard}, title = {The Use of Fusicoccin as Anticancer Compound}, series = {Carbon Nanomaterials in Biomedicine and the Environment}, booktitle = {Carbon Nanomaterials in Biomedicine and the Environment}, publisher = {Jenny Stanford Publishing}, address = {New York}, isbn = {978-0-429-42864-7}, doi = {10.1201/9780429428647-8}, pages = {149 -- 172}, year = {2020}, abstract = {The problem of creation and use of sorption materials is of current interest for the practice of the modern medicine and agriculture. Practical importance is production of a biostimulant using a carbon sorbent for a significant increase in productivity, which is very relevant for the regions of Kazakhstan. It is known that a plant phytohormone—fusicoccin—in nanogram concentrations transforms cancer cells to the state of apoptosis. In this regard, there is a scientific practical interest in the development of a highly efficient method for producing fusicoccin from extract of germinated wheat seeds. According to the results of computer modeling, cleaning composite components of fusicoccin using microporous carbon adsorbents not suitable as the size of the molecule of fusicoccin more than micropores and the optimum pore size for purification of constituents of fusicoccin was determined by computer simulation.}, language = {en} } @inproceedings{BaaderKellerLehmannetal.2019, author = {Baader, Fabian and Keller, Denis and Lehmann, Raphael and Gerber, Lukas and Reiswich, Martin and Dachwald, Bernd and F{\"o}rstner, Roger}, title = {Operating melting probes for ice penetration under sublimation conditions and in reduced gravity on a sounding rocket}, series = {Proceedings of the 24th ESA Symposium on European Rocket and Balloon Programmes and related Research}, booktitle = {Proceedings of the 24th ESA Symposium on European Rocket and Balloon Programmes and related Research}, issn = {0379-6566}, pages = {8 Seiten}, year = {2019}, language = {en} } @inproceedings{BaaderReiswichBartschetal.2018, author = {Baader, Fabian and Reiswich, M. and Bartsch, M. and Keller, D. and Tiede, E. and Keck, G. and Demircian, A. and Friedrich, M. and Dachwald, Bernd and Sch{\"u}ller, K. and Lehmann, R. and Chojetzki, R. and Durand, C. and Rapp, L. and Kowalski, Julia and F{\"o}rstner, R.}, title = {VIPER - Student research on extraterrestrical ice penetration technology}, series = {Proceedings of the 2nd Symposium on Space Educational Activities}, booktitle = {Proceedings of the 2nd Symposium on Space Educational Activities}, pages = {1 -- 6}, year = {2018}, abstract = {Recent analysis of scientific data from Cassini and earth-based observations gave evidence for a global ocean under a surrounding solid ice shell on Saturn's moon Enceladus. Images of Enceladus' South Pole showed several fissures in the ice shell with plumes constantly exhausting frozen water particles, building up the E-Ring, one of the outer rings of Saturn. In this southern region of Enceladus, the ice shell is considered to be as thin as 2 km, about an order of magnitude thinner than on the rest of the moon. Under the ice shell, there is a global ocean consisting of liquid water. Scientists are discussing different approaches the possibilities of taking samples of water, i.e. by melting through the ice using a melting probe. FH Aachen UAS developed a prototype of maneuverable melting probe which can navigate through the ice that has already been tested successfully in a terrestrial environment. This means no atmosphere and or ambient pressure, low ice temperatures of around 100 to 150K (near the South Pole) and a very low gravity of 0,114 m/s^2 or 1100 μg. Two of these influencing measures are about to be investigated at FH Aachen UAS in 2017, low ice temperature and low ambient pressure below the triple point of water. Low gravity cannot be easily simulated inside a large experiment chamber, though. Numerical simulations of the melting process at RWTH Aachen however are showing a gravity dependence of melting behavior. Considering this aspect, VIPER provides a link between large-scale experimental simulations at FH Aachen UAS and numerical simulations at RWTH Aachen. To analyze the melting process, about 90 seconds of experiment time in reduced gravity and low ambient pressure is provided by the REXUS rocket. In this time frame, the melting speed and contact force between ice and probes are measured, as well as heating power and a two-dimensional array of ice temperatures. Additionally, visual and infrared cameras are used to observe the melting process.}, language = {en} } @article{BalakirskiKotliarPaulyetal.2018, author = {Balakirski, Galina and Kotliar, Konstantin and Pauly, Karolin J. and Krings, Laura K. and R{\"u}bben, Albert and Baron, Jens M. and Schmitt, Laurenz}, title = {Surgical Site Infections After Dermatologic Surgery in Immunocompromised Patients: A Single-Center Experience}, series = {Dermatologic Surgery}, journal = {Dermatologic Surgery}, number = {44 (12)}, publisher = {Wolters Kluwer}, doi = {10.1097/DSS.0000000000001615}, pages = {1525 -- 1536}, year = {2018}, abstract = {BACKGROUND Immunosuppression is often considered as an indication for antibiotic prophylaxis to prevent surgical site infections (SSI) while performing skin surgery. However, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. PATIENTS AND METHODS All patients of the Department of Dermatology and Allergology at the University Hospital of RWTH Aachen in Aachen, Germany, who underwent hospitalization for a dermatologic surgery between June 2016 and January 2017 (6 months), were followed up after surgery until completion of the wound healing process. The follow-up addressed the occurrence of SSI and the need for systemic antibiotics after the operative procedure. Immunocompromised patients were compared with immunocompetent patients. The investigation was conducted as a retrospective analysis of patient records. RESULTS The authors performed 284 dermatologic surgeries in 177 patients. Nineteen percent (54/284) of the skin surgery was performed on immunocompromised patients. The most common indications for surgical treatment were nonmelanoma skin cancer and malignant melanomas. Surgical site infections occurred in 6.7\% (19/284) of the cases. In 95\% (18/19), systemic antibiotic treatment was needed. Twenty-one percent of all SSI (4/19) were seen in immunosuppressed patients. CONCLUSION According to the authors' data, immunosuppression does not represent a significant risk factor for SSI after dermatologic surgery. However, larger prospective studies are needed to make specific recommendations on the use of antibiotic prophylaxis while performing skin surgery in these patients. The available data on complications after dermatologic surgery have improved over the past years. Particularly, additional risk factors have been identified for surgical site infections (SSI). Purulent surgical sites, older age, involvement of head, neck, and acral regions, and also the involvement of less experienced surgeons have been reported to increase the risk of the SSI after dermatologic surgeries.1 In general, the incidence of SSI after skin surgery is considered to be low.1,2 However, antibiotics in dermatologic surgeries, especially in the perioperative setting, seem to be overused,3,4 particularly regarding developing antibiotic resistances and side effects. Immunosuppression has been recommended to be taken into consideration as an additional indication for antibiotic prophylaxis to prevent SSI after skin surgery in special cases.5,6 However, these recommendations do not specify the exact dermatologic surgeries, and were not specifically developed for dermatologic surgery patients and treatments, but adopted from other surgical fields.6 According to the survey conducted on American College of Mohs Surgery members in 2012, 13\% to 29\% of the surgeons administered antibiotic prophylaxis to immunocompromised patients to prevent SSI while performing dermatologic surgery on noninfected skin,3 although this was not recommended by Journal of the American Academy of Dermatology Advisory Statement. Indeed, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. However, it is possible that due to the insufficient evidence on the risk of SSI occurrence in this patient group, dermatologic surgeons tend to overuse perioperative antibiotic prophylaxis. To make specific recommendations on the use of antibiotic prophylaxis in immunosuppressed patients in the field of skin surgery, more information about the incidence of SSI after dermatologic surgery in these patients is needed. The aim of this study was to fill this data gap by investigating whether there is an increased risk of SSI after skin surgery in immunocompromised patients compared with immunocompetent patients.}, language = {en} } @article{BaroudWuBohneretal.2003, author = {Baroud, G. and Wu, J.Z. and Bohner, M and Sponagel, Stefan and Steffen, T.}, title = {How to determine the permeability for cement infiltration into osteoporotic cancellous bone}, series = {Medical Engineering \& Physics. 25 (2003), H. 4}, journal = {Medical Engineering \& Physics. 25 (2003), H. 4}, issn = {1350-4533}, pages = {283 -- 288}, year = {2003}, abstract = {Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63\% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.}, subject = {Osteoporose}, language = {en} } @article{BassamArtmannHescheleretal.2011, author = {Bassam, Rasha and Artmann, Gerhard and Hescheler, J{\"u}rgen and Graef, T. and Temiz Artmann, Ayseg{\"u}l and Porst, Dariusz and Linder, Peter and Kayser, Peter and Arinkin, Vladimir and Gossmann, Matthias and Digel, Ilya}, title = {Alterations in human hemoglobin structure related to red blood cell storage}, year = {2011}, abstract = {The importance of the availability of stored blood or blood cells, respectively, for urgent transfusion cannot be overestimated. Nowadays, blood storage becomes even more important since blood products are used for epidemiological studies, bio-technical research or banked for transfusion purposes. Thus blood samples must not only be processed, stored, and shipped to preserve their efficacy and safety, but also all parameters of storage must be recorded and reported for Quality Assurance. Therefore, blood banks and clinical research facilities are seeking more accurate, automated means for blood storage and blood processing.}, subject = {H{\"a}moglobin}, language = {en} } @inproceedings{BassamDigelArtmann2009, author = {Bassam, Rasha and Digel, Ilya and Artmann, Gerhard}, title = {Effect of nitric oxide on protein thermal stability : [abstract]}, year = {2009}, abstract = {As a deduction from these results, we can conclude that proteins mainly in vitro, denaturate totally at a temperature between 57°C -62°C, and they also affected by NO and different ions types. In which mainly, NO cause earlier protein denaturation, which means that, NO has a destabilizing effect on proteins, and also different ions will alter the protein denaturation in which, some ions will cause earlier protein denaturation while others not.}, subject = {Stickstoffmonoxid}, language = {en} } @article{BassamDigelHescheleretal.2013, author = {Bassam, Rasha and Digel, Ilya and Hescheler, J{\"u}rgen and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard}, title = {Effects of spermine NONOate and ATP on protein aggregation: light scattering evidences}, series = {BMC Biophysics}, journal = {BMC Biophysics}, publisher = {BioMed Central}, address = {London}, isbn = {2046-1682}, url = {http://nbn-resolving.de/10.1186/2046-1682-6-1}, pages = {1 -- 14}, year = {2013}, language = {en} } @article{BassamHeschelerTemizArtmannetal.2012, author = {Bassam, Rasha and Hescheler, J{\"u}rgen and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard and Digel, Ilya}, title = {Effects of spermine NONOate and ATP on the thermal stability of hemoglobin}, series = {BMC Biophysics}, volume = {5}, journal = {BMC Biophysics}, publisher = {BioMed Central}, address = {London}, issn = {2046-1682}, doi = {10.1186/2046-1682-5-16}, pages = {Art. 16}, year = {2012}, abstract = {Background Minor changes in protein structure induced by small organic and inorganic molecules can result in significant metabolic effects. The effects can be even more profound if the molecular players are chemically active and present in the cell in considerable amounts. The aim of our study was to investigate effects of a nitric oxide donor (spermine NONOate), ATP and sodium/potassium environment on the dynamics of thermal unfolding of human hemoglobin (Hb). The effect of these molecules was examined by means of circular dichroism spectrometry (CD) in the temperature range between 25°C and 70°C. The alpha-helical content of buffered hemoglobin samples (0.1 mg/ml) was estimated via ellipticity change measurements at a heating rate of 1°C/min. Results Major results were: 1) spermine NONOate persistently decreased the hemoglobin unfolding temperature T u irrespectively of the Na + /K + environment, 2) ATP instead increased the unfolding temperature by 3°C in both sodium-based and potassium-based buffers and 3) mutual effects of ATP and NO were strongly influenced by particular buffer ionic compositions. Moreover, the presence of potassium facilitated a partial unfolding of alpha-helical structures even at room temperature. Conclusion The obtained data might shed more light on molecular mechanisms and biophysics involved in the regulation of protein activity by small solutes in the cell.}, language = {en} } @article{BaumannSchwarzKotliaretal.2009, author = {Baumann, Marcus and Schwarz, Sonja and Kotliar, Konstantin and Eynatten, Maximilian von and Trucksaess, Arno and Burckhardt, Klaus and Lutz, Jens and Heemann, Uwe and Lanzl, Ines}, title = {Non-diabetic chronic kidney disease influences retinal microvasculature}, series = {Kidney and Blood Pressure Research}, volume = {32}, journal = {Kidney and Blood Pressure Research}, number = {6}, publisher = {-}, isbn = {1423-0143}, pages = {428 -- 433}, year = {2009}, language = {en} } @phdthesis{Bayer2021, author = {Bayer, Robin}, title = {Development of a novel in-vitro vascular model for determination of physiological and pathophysiological mechanobiology}, publisher = {Universit{\"a}t zu K{\"o}ln}, address = {K{\"o}ln}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:38-362212}, pages = {IV, 115 Seiten}, year = {2021}, language = {en} } @inproceedings{BayerHeschelerArtmannetal.2019, author = {Bayer, Robin and Hescheler, J{\"u}rgen and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Treating arterial hypertension in a cell culture well}, series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH AachenW}, booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH AachenW}, editor = {Staat, Manfred and Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-22-6}, doi = {10.17185/duepublico/48750}, pages = {5 -- 6}, year = {2019}, abstract = {Hypertension describes the pathological increase of blood pressure, which is most commonly associated with the increase of vascular wall stiffness [1]. Referring to the "Deutsche Bluthochdruck Liga" this pathology shows a growing trend in our aging society. In order to find novel pharmacological and probably personalized treatments, we want to present a functional approach to study biomechanical properties of a human aortic vascular model. In this method review we will give an overview of recent studies which were carried out with the CellDrum technology [2] and underline the added value to already existing standard procedures known from the field of physiology. Herein described CellDrum technology is a system to measure functional mechanical properties of cell monolayers and thin tissue constructs in-vitro. Additionally, the CellDrum enables to elucidate the mechanical response of cells to pharmacological drugs, toxins and vasoactive agents. Due to its highly flexible polymer support, cells can also be mechanically stimulated by steady and cyclic biaxial stretching.}, language = {en} } @article{BayerTemizArtmannDigeletal.2020, author = {Bayer, Robin and Temiz Artmann, Ayseg{\"u}l and Digel, Ilya and Falkenstein, Julia and Artmann, Gerhard and Creutz, Till and Hescheler, J{\"u}rgen}, title = {Mechano-pharmacological testing of L-Type Ca²⁺ channel modulators via human vascular celldrum model}, series = {Cellular Physiology and Biochemistry}, volume = {54}, journal = {Cellular Physiology and Biochemistry}, publisher = {Cell Physiol Biochem Press}, address = {D{\"u}sseldorf}, issn = {1421-9778}, doi = {10.33594/000000225}, pages = {371 -- 383}, year = {2020}, abstract = {Background/Aims: This study aimed to establish a precise and well-defined working model, assessing pharmaceutical effects on vascular smooth muscle cell monolayer in-vitro. It describes various analysis techniques to determine the most suitable to measure the biomechanical impact of vasoactive agents by using CellDrum technology. Methods: The so-called CellDrum technology was applied to analyse the biomechanical properties of confluent human aorta muscle cells (haSMC) in monolayer. The cell generated tensions deviations in the range of a few N/m² are evaluated by the CellDrum technology. This study focuses on the dilative and contractive effects of L-type Ca²⁺ channel agonists and antagonists, respectively. We analyzed the effects of Bay K8644, nifedipine and verapamil. Three different measurement modes were developed and applied to determine the most appropriate analysis technique for the study purpose. These three operation modes are called, particular time mode" (PTM), "long term mode" (LTM) and "real-time mode" (RTM). Results: It was possible to quantify the biomechanical response of haSMCs to the addition of vasoactive agents using CellDrum technology. Due to the supplementation of 100nM Bay K8644, the tension increased approximately 10.6\% from initial tension maximum, whereas, the treatment with nifedipine and verapamil caused a significant decrease in cellular tension: 10nM nifedipine decreased the biomechanical stress around 6,5\% and 50nM verapamil by 2,8\%, compared to the initial tension maximum. Additionally, all tested measurement modes provide similar results while focusing on different analysis parameters. Conclusion: The CellDrum technology allows highly sensitive biomechanical stress measurements of cultured haSMC monolayers. The mechanical stress responses evoked by the application of vasoactive calcium channel modulators were quantified functionally (N/m²). All tested operation modes resulted in equal findings, whereas each mode features operation-related data analysis.}, language = {en} } @article{BeckerWallangArtmannetal.2008, author = {Becker, C. and Wallang, C. and Artmann, Gerhard and Jakse, G.}, title = {Mechanotransduction-bioreactor for tissue engineering of a ureter prosthesis}, series = {International Journal of Artificial Organs, The}, volume = {31}, journal = {International Journal of Artificial Organs, The}, number = {7}, issn = {0391-3988}, pages = {583 -- 583}, year = {2008}, language = {en} } @inproceedings{Behbahani2014, author = {Behbahani, Mehdi}, title = {An Experimental Study of Thrombocyte Reactions in Response to Biomaterial Surfaces and Varying Shear Stress}, series = {Proceedings of the International Conference on Biomedical Engineering and Systems Prague, Czech Republic, August 14-15, 2014}, booktitle = {Proceedings of the International Conference on Biomedical Engineering and Systems Prague, Czech Republic, August 14-15, 2014}, pages = {Paper 125}, year = {2014}, language = {en} } @phdthesis{Behbahani2011, author = {Behbahani, Mehdi}, title = {Modeling and Simulation of Shear-Dependent Platelet Reactions in Blood Vessels and Blood-Contacting Medical Devices}, publisher = {Verlag Dr. Hut}, address = {M{\"u}nchen}, isbn = {978-3-8439-0134-5}, year = {2011}, language = {en} } @article{BehbahaniBehrAroraetal.2006, author = {Behbahani, Mehdi and Behr, M. and Arora, D. and Coronado, O. and Pasquali, M.}, title = {CFD Analysis of MicroMed Debakey Pump and Hemolysis Prediction / Behbahani, M. ; Behr, M. ; Arora, D. ; Coronado, O. ; Pasquali, M.}, series = {Artificial Organs. 30 (2006), H. 11}, journal = {Artificial Organs. 30 (2006), H. 11}, isbn = {1525-1594}, pages = {A45 -- A46}, year = {2006}, language = {en} } @article{BehbahaniBehrHormesetal.2009, author = {Behbahani, Mehdi and Behr, M. and Hormes, M. and Steinseifer, U. and Arora, D. and Coronado, O. and Pasquali, M.}, title = {A Review of Computational Fluid Dynamics Analysis of Blood Pumps}, series = {European Journal of Applied Mathematics. 20 (2009), H. 4}, journal = {European Journal of Applied Mathematics. 20 (2009), H. 4}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, pages = {363 -- 397}, year = {2009}, language = {en} } @article{BehbahaniBehrNicolaietal.2008, author = {Behbahani, Mehdi and Behr, Marek and Nicolai, Mike and Probst, Markus}, title = {Towards Shape Optimization for Ventricular Assist Devices Using Parallel Stabilized FEM}, series = {NIC Symposium 2008 : symposium, 20 - 21 February 2008, Forschungszentrum J{\"u}lich ; proceedings / organized by John von Neumann Institute for Computing. Ed. by Gernot M{\"u}nster; Dietrich Wolf; Manfred Kremer (ed.)}, journal = {NIC Symposium 2008 : symposium, 20 - 21 February 2008, Forschungszentrum J{\"u}lich ; proceedings / organized by John von Neumann Institute for Computing. Ed. by Gernot M{\"u}nster; Dietrich Wolf; Manfred Kremer (ed.)}, publisher = {Forschungszentrum}, address = {J{\"u}lich}, isbn = {978-3-9810843-5-1}, pages = {325 -- 332}, year = {2008}, language = {en} } @article{BehbahaniFinocchiaroHeinkeetal.2009, author = {Behbahani, Mehdi and Finocchiaro, Thomas and Heinke, Stefanie and Leßmann, Marc}, title = {Methods of design, simulation, and control for the development of new VAD/TAH concepts = Methoden zur Konstruktion, Simulation und Regelung f{\"u}r die Entwicklung von neuen VAD/TAH-Konzepten / Finocchiaro, Thomas ; Heinke, Stefanie ; Behbahani, Mehdi ; Leßma}, series = {Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5}, journal = {Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5}, isbn = {0013-5585}, pages = {269 -- 281}, year = {2009}, language = {en} } @article{BehbahaniMaiBergmannetal.2010, author = {Behbahani, Mehdi and Mai, A. and Bergmann, B. and Waluga, C. and Behr, M. and Tran, L. and Vonderstein, K. and Mottaghy, K.}, title = {Modeling and Numerical Simulation of Blood Damage}, year = {2010}, language = {en} } @article{BehbahaniMaiWalugaetal.2010, author = {Behbahani, Mehdi and Mai, A. and Waluga, C. and Bergmann, B. and Tran, L. and Vonderstein, K. and Behr, M. and Mottaghy, K.}, title = {Numerical Modeling of Flow-Related Thrombus Formation under Physiological and Non-Physiological Flow Conditions}, series = {Acta Physiologica}, volume = {198}, journal = {Acta Physiologica}, number = {Supplement 677}, isbn = {1748-1716}, pages = {185}, year = {2010}, language = {en} } @article{BehbahaniNamWalugaetal.2010, author = {Behbahani, Mehdi and Nam, J. and Waluga, C. and Behr, M. and Pasquali, M. and Mottaghy, K.}, title = {Modeling and Numerical Analysis of Platelet Activation, Adhesion and Aggregation in Artificial Organs}, doi = {10.1097/01.mat.0000369377.65122.a3}, year = {2010}, language = {en} } @article{BehbahaniNicolaiProbstetal.2007, author = {Behbahani, Mehdi and Nicolai, M. and Probst, M. and Behr, M.}, title = {Simulation of Blood Flow in a Ventricular Assist Device}, series = {inSIDE. 5 (2007), H. 1}, journal = {inSIDE. 5 (2007), H. 1}, pages = {28 -- 31}, year = {2007}, language = {en} } @article{BehbahaniProbstMaietal.2010, author = {Behbahani, Mehdi and Probst, M. and Mai, A. and Behr, M. and Tran, L. and Vonderstein, K. and Mottaghy, K.}, title = {Numerical Prediction of Blood Damage in Biomedical Devices}, year = {2010}, language = {en} } @article{BehbahaniProbstMaietal.2010, author = {Behbahani, Mehdi and Probst, M. and Mai, A. and Tran, L. and Vonderstein, K. and Keschenau, P. and Linde, T. and Steinseifer, U. and Behr, M. and Mottaghy, K.}, title = {The influence of high shear on thrombosis and hemolysis in artificial organs}, series = {Artificial Organs}, volume = {33}, journal = {Artificial Organs}, number = {7}, isbn = {0391-3988}, pages = {426 -- 426}, year = {2010}, language = {en} } @inproceedings{BehbahaniRibleMoulinecetal.2015, author = {Behbahani, Mehdi and Rible, Sebastian and Moulinec, Charles and Fournier, Yvan and Nicolai, Mike and Crosetto, Paolo}, title = {Simulation of the FDA Centrifugal Blood Pump Using High Performance Computing}, series = {World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering}, volume = {9}, booktitle = {World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering}, number = {5}, year = {2015}, language = {en} } @article{BehbahaniTranJockenhoeveletal.2011, author = {Behbahani, Mehdi and Tran, L. and Jockenh{\"o}vel, S. and Behr, M. and Mottaghy, K.}, title = {Numerical prediction of thrombocyte reactions for application to a vascular flow model}, series = {British Journal of Surgery}, volume = {98}, journal = {British Journal of Surgery}, number = {S5}, publisher = {Oxford University Press}, address = {Oxford}, isbn = {1365-2168}, pages = {S17}, year = {2011}, language = {en} } @article{BehbahaniTranWalugaetal.2009, author = {Behbahani, Mehdi and Tran, L. and Waluga, C. and Behr, M. and Oedekoven, B. and Mottaghy, K.}, title = {Model-based Numerical Analysis of Platelet Adhesion, Thrombus Growth and Aggregation for Assist Devices}, series = {The International Journal of Artificial Organs. 32 (2009), H. 7}, journal = {The International Journal of Artificial Organs. 32 (2009), H. 7}, isbn = {0391-3988}, pages = {398 -- 398}, year = {2009}, language = {en} } @article{BehbahaniWalugaArltetal.2008, author = {Behbahani, Mehdi and Waluga, C. and Arlt, S. and Behr, M. and Mottaghy, K.}, title = {Computational Analysis of Platelet Aggregation in a Taylor-Couette System}, series = {The International Journal of Artificial Organs. 31 (2008), H. 7}, journal = {The International Journal of Artificial Organs. 31 (2008), H. 7}, isbn = {0391-3988}, pages = {643}, year = {2008}, language = {en} } @article{BehbahaniWalugaStocketal.2009, author = {Behbahani, Mehdi and Waluga, C. and Stock, S. and Mai, A. and Bergmann, B. and Behr, M. and Tran, L. and Vonderstein, K. and Scheidt, H. and Oedekoven, B. and Mottaghy, K.}, title = {Modelling and Numerical Analysis of Platelet Reactions and Surface Thrombus Growth}, year = {2009}, language = {en} } @article{BelavyAlbrachtBruggemannetal.2016, author = {Belavy, Daniel L. and Albracht, Kirsten and Bruggemann, Gert-Peter and Vergroesen, Pieter-Paul A. and Dieen, Jaap H. van}, title = {Can exercise positively influence the intervertebral disc?}, series = {Sports Medicine}, volume = {46}, journal = {Sports Medicine}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1179-2035}, doi = {10.1007/s40279-015-0444-2}, pages = {473 -- 485}, year = {2016}, abstract = {To better understand what kinds of sports and exercise could be beneficial for the intervertebral disc (IVD), we performed a review to synthesise the literature on IVD adaptation with loading and exercise. The state of the literature did not permit a systematic review; therefore, we performed a narrative review. The majority of the available data come from cell or whole-disc loading models and animal exercise models. However, some studies have examined the impact of specific sports on IVD degeneration in humans and acute exercise on disc size. Based on the data available in the literature, loading types that are likely beneficial to the IVD are dynamic, axial, at slow to moderate movement speeds, and of a magnitude experienced in walking and jogging. Static loading, torsional loading, flexion with compression, rapid loading, high-impact loading and explosive tasks are likely detrimental for the IVD. Reduced physical activity and disuse appear to be detrimental for the IVD. We also consider the impact of genetics and the likelihood of a 'critical period' for the effect of exercise in IVD development. The current review summarises the literature to increase awareness amongst exercise, rehabilitation and ergonomic professionals regarding IVD health and provides recommendations on future directions in research.}, language = {en} } @phdthesis{Bhattarai2018, author = {Bhattarai, Aroj}, title = {Constitutive modeling of female pelvic floor dysfunctions and reconstructive surgeries using prosthetic mesh implants}, isbn = {978-3-9818074-8-6}, doi = {10.17185/duepublico/70340}, pages = {192 S.}, year = {2018}, language = {en} } @inproceedings{BhattaraiFrotscherSoraetal.2014, author = {Bhattarai, Aroj and Frotscher, Ralf and Sora, M.-C. and Staat, Manfred}, title = {A 3D finite element model of the female pelvic floor for the reconstruction of urinary incontinence}, series = {11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona}, booktitle = {11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona}, editor = {Onate, E.}, organization = {World Congress on Computational Mechanics <11, 2014, Barcelona>}, pages = {1 -- 12}, year = {2014}, language = {en} } @inproceedings{BhattaraiFrotscherStaat2015, author = {Bhattarai, Aroj and Frotscher, Ralf and Staat, Manfred}, title = {Biomechanical study of the female pelvic floor dysfunction using the finite element method}, series = {Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon}, booktitle = {Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon}, publisher = {RWTH Aachen University}, address = {Aachen}, organization = {ECCOMAS Young Investigators Conference <3, 2015, Aachen>}, pages = {1 -- 4}, year = {2015}, language = {en} } @inproceedings{BhattaraiFrotscherStaat2016, author = {Bhattarai, Aroj and Frotscher, Ralf and Staat, Manfred}, title = {Significance of fibre geometry on passive-active response of pelvic muscles to evaluate pelvic dysfunction}, series = {BioMedWomen: Proceedings of the international conference on clinical and bioengineering for women's health}, booktitle = {BioMedWomen: Proceedings of the international conference on clinical and bioengineering for women's health}, editor = {Natal Jorge, Renato}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {978-1-138-02910-1}, pages = {185 -- 188}, year = {2016}, language = {en} } @incollection{BhattaraiFrotscherStaat2018, author = {Bhattarai, Aroj and Frotscher, Ralf and Staat, Manfred}, title = {Computational Analysis of Pelvic Floor Dysfunction}, series = {Women's Health and Biomechanics}, booktitle = {Women's Health and Biomechanics}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-71574-2}, doi = {10.1007/978-3-319-71574-2_17}, pages = {217 -- 230}, year = {2018}, abstract = {Pelvic floor dysfunction (PFD) is characterized by the failure of the levator ani (LA) muscle to maintain the pelvic hiatus, resulting in the descent of the pelvic organs below the pubococcygeal line. This chapter adopts the modified Humphrey material model to consider the effect of the muscle fiber on passive stretching of the LA muscle. The deformation of the LA muscle subjected to intra-abdominal pressure during Valsalva maneuver is compared with the magnetic resonance imaging (MRI) examination of a nulliparous female. Numerical result shows that the fiber-based Humphrey model simulates the muscle behavior better than isotropic constitutive models. Greater posterior movement of the LA muscle widens the levator hiatus due to lack of support from the anococcygeal ligament and the perineal structure as a consequence of birth-related injury and aging. Old and multiparous females with uncontrolled urogenital and rectal hiatus tend to develop PFDs such as prolapse and incontinence.}, language = {en} } @article{BhattaraiHorbachStaatetal.2022, author = {Bhattarai, Aroj and Horbach, Andreas and Staat, Manfred and Kowalczyk, Wojciech and Tran, Thanh Ngoc}, title = {Virgin passive colon biomechanics and a literature review of active contraction constitutive models}, series = {Biomechanics}, volume = {2}, journal = {Biomechanics}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2673-7078}, doi = {10.3390/biomechanics2020013}, pages = {138 -- 157}, year = {2022}, abstract = {The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel-Gasser-Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill's three-element model, Murphy's four-state cross-bridge chemical kinetic model and Huxley's sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.}, language = {en} } @article{BhattaraiJabbariAndingetal.2018, author = {Bhattarai, Aroj and Jabbari, Medisa and Anding, Ralf and Staat, Manfred}, title = {Surgical treatment of vaginal vault prolapse using different prosthetic mesh implants: a finite element analysis}, series = {tm - Technisches Messen}, volume = {85}, journal = {tm - Technisches Messen}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {2196-7113}, doi = {10.1515/teme-2017-0115}, pages = {331 -- 342}, year = {2018}, abstract = {Particularly multiparous elderly women may suffer from vaginal vault prolapse after hysterectomy due to weak support from lax apical ligaments. A decreased amount of estrogen and progesterone in older age is assumed to remodel the collagen thereby reducing tissue stiffness. Sacrocolpopexy is either performed as open or laparoscopic surgery using prosthetic mesh implants to substitute lax ligaments. Y-shaped mesh models (DynaMesh, Gynemesh, and Ultrapro) are implanted in a 3D female pelvic floor finite element model in the extraperitoneal space from the vaginal cuff to the first sacral (S1) bone below promontory. Numerical simulations are conducted during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues are modeled as incompressible, isotropic hyperelastic materials whereas the meshes are modeled either as orthotropic linear elastic or as isotropic hyperlastic materials. The positions of the vaginal cuff and the bladder base are calculated from the pubococcygeal line for female pelvic floor at rest, for prolapse and after repair using the three meshes. Due to mesh mechanics and mesh pore deformation along the loaded direction, the DynaMesh with regular rectangular mesh pores is found to provide better mechanical support to the organs than the Gynemesh and the Ultrapro with irregular hexagonal mesh pores. Insbesondere {\"a}ltere, mehrgeb{\"a}hrende Frauen leiden h{\"a}ufiger an einem Scheidenvorfall nach einer Hysterektomie aufgrund der schwachen Unterst{\"u}tzung durch laxe apikale B{\"a}nder. Es wird angenommen, dass eine verringerte Menge an {\"O}strogen und Progesteron im h{\"o}heren Alter das Kollagen umformt, wodurch die Gewebesteifigkeit reduziert wird. Die Sakrokolpopexie ist eine offene oder laparoskopische Operation, die mit prothetischen Netzimplantaten durchgef{\"u}hrt wird, um laxe B{\"a}nder zu ersetzen. Y-f{\"o}rmige Netzmodelle (DynaMesh, Gynemesh und Ultrapro) werden in einem 3D-Modell des weiblichen Beckenbodens im extraperitonealen Raum vom Vaginalstumpf bis zum Promontorium implantiert. Numerische Simulationen werden w{\"a}hrend des Valsalva-Man{\"o}vers mit geschw{\"a}chtem Gewebe durchgef{\"u}hrt, das durch eine reduzierte Gewebesteifigkeit modelliert wird. Die Gewebe werden als inkompressible, isotrop hyperelastische Materialien modelliert, w{\"a}hrend die Netze entweder als orthotrope linear elastische oder als isotrope hyperlastische Materialien modelliert werden. Die Positionen des Vaginalstumpfs, der Blase und der Harnr{\"o}hrenachse werden anhand der Pubococcygeallinie aus der Ruhelage, f{\"u}r den Prolaps und nach der Reparatur unter Verwendung der drei Netze berechnet. Aufgrund der Netzmechanik und der Netzporenverformung bietet das DynaMesh mit regelm{\"a}ßigen rechteckigen Netzporen eine bessere mechanische Unterst{\"u}tzung und eine Neupositionierung des Scheidengew{\"o}lbes, der Blase und der Urethraachse als Gynemesh und Ultrapro mit unregelm{\"a}ßigen hexagonalen Netzporen.}, language = {en} } @article{BhattaraiMayStaatetal.2022, author = {Bhattarai, Aroj and May, Charlotte Anabell and Staat, Manfred and Kowalczyk, Wojciech and Tran, Thanh Ngoc}, title = {Layer-specific damage modeling of porcine large intestine under biaxial tension}, series = {Bioengineering}, volume = {9}, journal = {Bioengineering}, number = {10, Early Access}, publisher = {MDPI}, address = {Basel}, issn = {2306-5354}, doi = {10.3390/bioengineering9100528}, pages = {1 -- 17}, year = {2022}, abstract = {The mechanical behavior of the large intestine beyond the ultimate stress has never been investigated. Stretching beyond the ultimate stress may drastically impair the tissue microstructure, which consequently weakens its healthy state functions of absorption, temporary storage, and transportation for defecation. Due to closely similar microstructure and function with humans, biaxial tensile experiments on the porcine large intestine have been performed in this study. In this paper, we report hyperelastic characterization of the large intestine based on experiments in 102 specimens. We also report the theoretical analysis of the experimental results, including an exponential damage evolution function. The fracture energies and the threshold stresses are set as damage material parameters for the longitudinal muscular, the circumferential muscular and the submucosal collagenous layers. A biaxial tensile simulation of a linear brick element has been performed to validate the applicability of the estimated material parameters. The model successfully simulates the biomechanical response of the large intestine under physiological and non-physiological loads.}, language = {en} } @inproceedings{BhattaraiStaat2016, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Female pelvic floor dysfunction: progress weakening of the support system}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, doi = {10.17185/duepublico/40821}, pages = {11 -- 12}, year = {2016}, abstract = {The structure of the female pelvic floor (PF) is an inter-related system of bony pelvis,muscles, pelvic organs, fascias, ligaments, and nerves with multiple functions. Mechanically, thepelvic organ support system are of two types: (I) supporting system of the levator ani (LA) muscle,and (II) the suspension system of the endopelvic fascia condensation [1], [2]. Significantdenervation injury to the pelvic musculature, depolimerization of the collagen fibrils of the softvaginal hammock, cervical ring and ligaments during pregnancy and vaginal delivery weakens thenormal functions of the pelvic floor. Pelvic organ prolapse, incontinence, sexual dysfunction aresome of the dysfunctions which increases progressively with age and menopause due toweakened support system according to the Integral theory [3]. An improved 3D finite elementmodel of the female pelvic floor as shown in Fig. 1 is constructed that: (I) considers the realisticsupport of the organs to the pelvic side walls, (II) employs the improvement of our previous FEmodel [4], [5] along with the patient based geometries, (III) incorporates the realistic anatomy andboundary conditions of the endopelvic (pubocervical and rectovaginal) fascia, and (IV) considersvarying stiffness of the endopelvic fascia in the craniocaudal direction [3]. Several computationsare carried out on the presented computational model with healthy and damaged supportingtissues, and comparisons are made to understand the physiopathology of the female PF disorders.}, language = {en} } @article{BhattaraiStaat2018, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Modelling of Soft Connective Tissues to Investigate Female Pelvic Floor Dysfunctions}, series = {Computational and Mathematical Methods in Medicine}, volume = {2018}, journal = {Computational and Mathematical Methods in Medicine}, number = {Article ID 9518076}, publisher = {Hindawi}, address = {New York, NY}, issn = {1748-6718}, doi = {10.1155/2018/9518076}, pages = {1 -- 16}, year = {2018}, abstract = {After menopause, decreased levels of estrogen and progesterone remodel the collagen of the soft tissues thereby reducing their stiffness. Stress urinary incontinence is associated with involuntary urine leakage due to pathological movement of the pelvic organs resulting from lax suspension system, fasciae, and ligaments. This study compares the changes in the orientation and position of the female pelvic organs due to weakened fasciae, ligaments, and their combined laxity. A mixture theory weighted by respective volume fraction of elastin-collagen fibre compound (5\%), adipose tissue (85\%), and smooth muscle (5\%) is adopted to characterize the mechanical behaviour of the fascia. The load carrying response (other than the functional response to the pelvic organs) of each fascia component, pelvic organs, muscles, and ligaments are assumed to be isotropic, hyperelastic, and incompressible. Finite element simulations are conducted during Valsalva manoeuvre with weakened tissues modelled by reduced tissue stiffness. A significant dislocation of the urethrovesical junction is observed due to weakness of the fascia (13.89 mm) compared to the ligaments (5.47 mm). The dynamics of the pelvic floor observed in this study during Valsalva manoeuvre is associated with urethral-bladder hypermobility, greater levator plate angulation, and positive Q-tip test which are observed in incontinent females.}, language = {en} } @incollection{BhattaraiStaat2018, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Mechanics of soft tissue reactions to textile mesh implants}, series = {Biological, Physical and Technical Basics of Cell Engineering}, booktitle = {Biological, Physical and Technical Basics of Cell Engineering}, editor = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7904-7}, doi = {10.1007/978-981-10-7904-7_11}, pages = {251 -- 275}, year = {2018}, abstract = {For pelvic floor disorders that cannot be treated with non-surgical procedures, minimally invasive surgery has become a more frequent and safer repair procedure. More than 20 million prosthetic meshes are implanted each year worldwide. The simple selection of a single synthetic mesh construction for any level and type of pelvic floor dysfunctions without adopting the design to specific requirements increase the risks for mesh related complications. Adverse events are closely related to chronic foreign body reaction, with enhanced formation of scar tissue around the surgical meshes, manifested as pain, mesh erosion in adjacent structures (with organ tissue cut), mesh shrinkage, mesh rejection and eventually recurrence. Such events, especially scar formation depend on effective porosity of the mesh, which decreases discontinuously at a critical stretch when pore areas decrease making the surgical reconstruction ineffective that further augments the re-operation costs. The extent of fibrotic reaction is increased with higher amount of foreign body material, larger surface, small pore size or with inadequate textile elasticity. Standardized studies of different meshes are essential to evaluate influencing factors for the failure and success of the reconstruction. Measurements of elasticity and tensile strength have to consider the mesh anisotropy as result of the textile structure. An appropriate mesh then should show some integration with limited scar reaction and preserved pores that are filled with local fat tissue. This chapter reviews various tissue reactions to different monofilament mesh implants that are used for incontinence and hernia repairs and study their mechanical behavior. This helps to predict the functional and biological outcomes after tissue reinforcement with meshes and permits further optimization of the meshes for the specific indications to improve the success of the surgical treatment.}, language = {en} } @inproceedings{BhattaraiStaat2018, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Pectopexy to repair vaginal vault prolapse: a finite element approach}, series = {Proceedings CMBBE 2018}, booktitle = {Proceedings CMBBE 2018}, editor = {Fernandes, P.R. and Tavares, J. M.}, year = {2018}, abstract = {The vaginal prolapse after hysterectomy (removal of the uterus) is often associated with the prolapse of the vaginal vault, rectum, bladder, urethra or small bowel. Minimally invasive surgery such as laparoscopic sacrocolpopexy and pectopexy are widely performed for the treatment of the vaginal prolapse with weakly supported vaginal vault after hysterectomy using prosthetic mesh implants to support (or strengthen) lax apical ligaments. Implants of different shape, size and polymers are selected depending on the patient's anatomy and the surgeon's preference. In this computational study on pectopexy, DynaMesh®-PRP soft, GYNECARE GYNEMESH® PS Nonabsorbable PROLENE® soft and Ultrapro® are tested in a 3D finite element model of the female pelvic floor. The mesh model is implanted into the extraperitoneal space and sutured to the vaginal stump with a bilateral fixation to the iliopectineal ligament at both sides. Numerical simulations are conducted at rest, after surgery and during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues and prosthetic meshes are modeled as incompressible, isotropic hyperelastic materials. The positions of the organs are calculated with respect to the pubococcygeal line (PCL) for female pelvic floor at rest, after repair and during Valsalva maneuver using the three meshes.}, language = {en} } @article{BhattaraiStaat2018, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Computational comparison of different textile implants to correct apical prolapse in females}, series = {Current Directions in Biomedical Engineering}, volume = {4}, journal = {Current Directions in Biomedical Engineering}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, doi = {10.1515/cdbme-2018-0159}, pages = {661 -- 664}, year = {2018}, abstract = {Prosthetic textile implants of different shapes, sizes and polymers are used to correct the apical prolapse after hysterectomy (removal of the uterus). The selection of the implant before or during minimally invasive surgery depends on the patient's anatomical defect, intended function after reconstruction and most importantly the surgeon's preference. Weakness or damage of the supporting tissues during childbirth, menopause or previous pelvic surgeries may put females in higher risk of prolapse. Numerical simulations of reconstructed pelvic floor with weakened tissues and organ supported by textile product models: DynaMesh®-PRS soft, DynaMesh®-PRP soft and DynaMesh®-CESA from FEG Textiletechnik mbH, Germany are compared.}, language = {en} } @article{BhattaraiStaat2019, author = {Bhattarai, Aroj and Staat, Manfred}, title = {A computational study of organ relocation after laparoscopic pectopexy to repair posthysterectomy vaginal vault prolapse}, series = {Computer Methods in Biomechanics and Biomedical Engineering: Imaging \& Visualization}, journal = {Computer Methods in Biomechanics and Biomedical Engineering: Imaging \& Visualization}, publisher = {Taylor \& Francis}, address = {London}, issn = {2168-1171}, doi = {10.1080/21681163.2019.1670095}, year = {2019}, language = {en} } @inproceedings{BirgelLeschingerWegmannetal.2017, author = {Birgel, Stefan and Leschinger, Tim and Wegmann, Kilian and Staat, Manfred}, title = {Calculation of muscle forces and joint reaction loads in shoulder area via an OpenSim based computer calculation}, series = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West}, booktitle = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West}, editor = {Erni, Daniel and Fischerauer, Alice and Himmel, J{\"o}rg and Seeger, Thomas and Thelen, Klaus}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-9814801-9-1}, doi = {10.17185/duepublico/43984}, pages = {116 -- 117}, year = {2017}, language = {en} } @article{BirgelLeschingerWegmannetal.2018, author = {Birgel, Stefan and Leschinger, Tim and Wegmann, Kilian and Staat, Manfred}, title = {Calculation of muscle forces and joint reaction loads in the shoulder area via an OpenSim based computer model}, series = {tm - Technisches Messen}, volume = {85}, journal = {tm - Technisches Messen}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {2196-7113}, doi = {10.1515/teme-2017-0114}, pages = {321 -- 330}, year = {2018}, abstract = {Using the OpenSim software and verified anatomical data, a computer model for the calculation of biomechanical parameters is developed and used to determine the effect of a reattachment of the Supraspinatus muscle with a medial displacement of the muscle attachment point, which may be necessary for a rupture of the supraspinatus tendon. The results include the influence of the operation on basic biomechanical parameters such as the lever arm, as well as the calculated the muscle activations for the supraspinatus and deltoid. In addition, the influence on joint stability is examined by an analysis of the joint reaction force. The study provides a detailed description of the used model, as well as medical findings to a reattachment of the supraspinatus. Mit der Software OpenSim und {\"u}berpr{\"u}ften anatomischen Daten wird ein Computermodell zur Berechnung von biomechanischen Parametern entwickelt und genutzt, um den Effekt einer Refixierung des Supraspinatusmuskels mit einer medialen Verschiebung des Muskelansatzpunktes zu ermitteln, wie sie unter anderem nach einem Riss der Supraspinatussehne notwendig sein kann. Die Ergebnisse umfassen hierbei den Einfluss der Operation auf grundlegende biomechanische Parameter wie den Hebelarm sowie die berechneten Muskelaktivierungen f{\"u}r den Supraspinatus und Deltoideus. Zus{\"a}tzlich wird der Einfluss auf die Gelenkstabilit{\"a}t betrachtet und durch eine Analyse der Gelenkreaktionskraft untersucht. Die Studie bietet eine detaillierte Beschreibung des genutzten Modells, sowie medizinische Erkenntnisse zu einer Refixierung des Supraspinatus.}, language = {en} } @article{BlomeSeboldtDachwaldetal.2004, author = {Blome, Hans-Joachim and Seboldt, Wolfgang and Dachwald, Bernd and Richter, Lutz}, title = {Proposal for an integrated European Space Exploration Study}, series = {Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch}, journal = {Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch}, publisher = {Univelt}, address = {San Diego, Calif.}, isbn = {0-87703-523-7}, pages = {XI, 432 S. : Ill., graph. Darst.}, year = {2004}, language = {en} } @misc{BlottnerHastermannMuckeltetal.2019, author = {Blottner, Dieter and Hastermann, Maria and Muckelt, Paul and Albracht, Kirsten and Schoenrock, Britt and Salanova, Michele and Warner, Martin and Gunga, Hans-Christian and Stokes, Maria}, title = {MYOTONES - Inflight muscle health status monitoring during long-duration space missions onboard the International Space Station: a single case study}, series = {IAC Papers Archive}, journal = {IAC Papers Archive}, publisher = {Pergamon}, address = {Oxford}, issn = {00741795}, pages = {2 Seiten}, year = {2019}, abstract = {The MYOTONES experiment is the first to monitor changes in the basic biomechanical properties (tone, elasticity and stiffness) of the resting human myofascial system due to microgravity with a oninvasive, portable device on board the ISS. The MyotonPRO device applies several brief mechanical stimuli to the surface of the skin, and the natural oscillation signals of the tissue beneath are detected and computed by the MyotonPRO. Thus, an objective, quick and easy determination of the state of the underlying tissue is possible. Two preflight, four inflight and four post flight measurements were performed on a male astronaut using the same 10 measurement points (MP) for each session. MPs were located on the plantar fascia, Achilles tendon, M. soleus, M. gastrocnemius, M. multifidus, M. splenius capitis, M. deltoideus anterior, M. rectus femoris, infrapatellar tendon, M. tibialis anterior. Subcutaneous tissues thickness above the MPs was measured using ultrasound imaging. Magnetic resonance images (MRI) of lower limb muscles and functional tests were also performed pre- and postflight. Our first measurements on board the ISS confirmed increased tone and stiffness of the lumbar multifidus muscle, an important trunk stabilizer, dysfunction of which is known to be associated with back pain. Furthermore, reduced tone and stiffness of Achilles tendon and plantar fascia were observed inflight vs. preflight, confirming previous findings from terrestrial analog studies and parabolic flights. Unexpectedly, the deltoid showed negative inflight changes in tone and stiffness, and increased elasticity, suggesting a potential risk of muscle atrophy in longer spaceflight that should be addressed by adequate inflight countermeasure protocols. Most values from limb and back MPS showed deflected patterns (in either directions) from inflight shortly after the re-entry phase on the landing day and one week later. Most parameter values then normalized to baseline after 3 weeks likely due to 1G re-adaptation and possible outcome of the reconditioning protocol. No major changes in subcutaneous tissues thickness above the MPs were found inflight vs preflight, suggesting no bias (i.e., fluid shift, extreme tissue thickening or loss). Pre- and postflight MRI and functional tests showed negligible changes in calf muscle size, power and force, which is likely due to training effects from current inflight exercise protocols. The MYOTONES experiment is currently ongoing to collect data from further crew members. The potential impact of this research is to better understand the effects of microgravity and countermeasures over the time course of an ISS mission cycle. This will enable exercise countermeasures to be tailored}, language = {en} } @inproceedings{BlumAlbannaBenninghausetal.2019, author = {Blum, Yannik and Albanna, Walid and Benninghaus, Anne and Kotliar, Konstantin}, title = {Vasomotion in retinal vessels of patients presenting post hemorrhagic hydrocephalus following subarachnoid hemorrhage}, series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, editor = {Staat, Manfred and Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-22-6}, doi = {10.17185/duepublico/48750}, pages = {38 -- 39}, year = {2019}, abstract = {Clearance of blood components and fluid drainage play a crucial role in subarachnoid hemorrhage (SAH) and post hemorrhagic hydrocephalus (PHH). With the involvement of interstitial fluid (ISF) and cerebrospinal fluid (CSF), two pathways for the clearance of fluid and solutes in the brain are proposed. Starting at the level of capillaries, flow of ISF follows along the basement membranes in the walls of cerebral arteries out of the parenchyma to drain into the lymphatics and CSF [1]-[3]. Conversely, it is shown that CSF enters the parenchyma between glial and pial basement membranes of penetrating arteries [4]-[6]. Nevertheless, the involved structures and the contribution of either flow pathway to fluid balance between the subarachnoid space and interstitial space remains controversial. Low frequency oscillations in vascular tone are referred to as vasomotion and corresponding vasomotion waves are modeled as the driving force for flow of ISF out of the parenchyma [7]. Retinal vessel analysis (RVA) allows non-invasive measurement of retinal vessel vasomotion with respect to diameter changes [8]. Thus, the aim of the study is to investigate vasomotion in RVA signals of SAH and PHH patients.}, language = {en} } @incollection{BorggrafeOhndorfDachwaldetal.2012, author = {Borggrafe, Andreas and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang}, title = {Analysis of interplanetary solar sail trajectories with attitude dynamics}, series = {Dynamics and Control of Space Systems 2012}, booktitle = {Dynamics and Control of Space Systems 2012}, publisher = {Univelt Inc}, address = {San Diego}, isbn = {978-0-87703-587-9}, pages = {1553 -- 1569}, year = {2012}, abstract = {We present a new approach to the problem of optimal control of solar sails for low-thrust trajectory optimization. The objective was to find the required control torque magnitudes in order to steer a solar sail in interplanetary space. A new steering strategy, controlling the solar sail with generic torques applied about the spacecraft body axes, is integrated into the existing low-thrust trajectory optimization software InTrance. This software combines artificial neural networks and evolutionary algorithms to find steering strategies close to the global optimum without an initial guess. Furthermore, we implement a three rotational degree-of-freedom rigid-body attitude dynamics model to represent the solar sail in space. Two interplanetary transfers to Mars and Neptune are chosen to represent typical future solar sail mission scenarios. The results found with the new steering strategy are compared to the existing reference trajectories without attitude dynamics. The resulting control torques required to accomplish the missions are investigated, as they pose the primary requirements to a real on-board attitude control system.}, language = {en} } @inproceedings{BorggraefeDachwald2010, author = {Borggr{\"a}fe, Andreas and Dachwald, Bernd}, title = {Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients}, series = {2nd International Symposium on Solar Sailing}, booktitle = {2nd International Symposium on Solar Sailing}, pages = {1 -- 6}, year = {2010}, abstract = {Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail's distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed "low" and "medium" sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model.}, language = {en} } @inproceedings{BraunsteinGoldmannAlbrachtetal.2013, author = {Braunstein, Bjoern and Goldmann, Jan-Peter and Albracht, Kirsten and Sanno, Maximilian and Willwacher, Steffen and Heinrich, Kai and Herrmann, Volker and Br{\"u}ggemann, Gert-Peter}, title = {Joint specific contribution of mechanical power and work during acceleration and top speed in elite sprinters}, series = {31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013}, booktitle = {31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013}, issn = {1999-4168}, year = {2013}, language = {en} } @article{BrockhausBehbahaniMurisetal.2021, author = {Brockhaus, Moritz K. and Behbahani, Mehdi and Muris, Farina and Jansen, Sebastian V. and Schmitz- Rode, Thomas and Steinseifer, Ulrich and Clauser, Johanna C.}, title = {In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept}, series = {Artificial Organs}, volume = {45}, journal = {Artificial Organs}, number = {12}, publisher = {Wiley}, address = {Weinheim}, issn = {1525-1594}, doi = {10.1111/aor.14046}, pages = {1513 -- 1521}, year = {2021}, abstract = {Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6\% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.}, language = {en} } @article{BurkhardtSchwarzPanetal.2009, author = {Burkhardt, Klaus and Schwarz, Sonja and Pan, Chengrui and Stelter, Felix and Kotliar, Konstantin and Eynatten, Maxilian von and Sollinger, Daniel and Lanzl, Ines and Heemann, Uwe and Baumann, Marcus}, title = {Myeloid-related protein 8/14 complex describes microcirculatory alterations in patients with type 2 diabetes and nephropathy}, series = {Cardiovascular Diabetology}, volume = {8}, journal = {Cardiovascular Diabetology}, number = {10}, publisher = {-}, isbn = {1475-2840}, pages = {1 -- 8}, year = {2009}, language = {en} } @article{CampenKowalskiLyonsetal.2019, author = {Campen, R. and Kowalski, Julia and Lyons, W.B. and Tulaczyk, S. and Dachwald, Bernd and Pettit, E. and Welch, K. A. and Mikucki, J.A.}, title = {Microbial diversity of an Antarctic subglacial community and high-resolution replicate sampling inform hydrological connectivity in a polar desert}, series = {Environmental Microbiology}, journal = {Environmental Microbiology}, number = {accepted article}, publisher = {Wiley}, address = {Weinheim}, issn = {1462-2920}, doi = {10.1111/1462-2920.14607}, year = {2019}, language = {en} } @article{CapriMorsianiSantoroetal.2019, author = {Capri, Miriam and Morsiani, Cristina and Santoro, Aurelia and Moriggi, Manuela and Conte, Maria and Martucci, Morena and Bellavista, Elena and Fabbri, Cristina and Giampieri, Enrico and Albracht, Kirsten and Fl{\"u}ck, Martin and Ruoss, Severin and Brocca, Lorenza and Canepari, Monica and Longa, Emanuela and Giulio, Irene Di and Bottinelli, Roberto and Cerretelli, Paolo and Salvioli, Stefano and Gelfi, Cecilia and Franceschi, Claudio and Narici, Marco and Rittweger, J{\"o}rn}, title = {Recovery from 6-month spaceflight at the International Space Station: muscle-related stress into a proinflammatory setting}, series = {The FASEB journal : official publication of the Federation of American Societies for Experimental Biology}, volume = {33}, journal = {The FASEB journal : official publication of the Federation of American Societies for Experimental Biology}, number = {4}, doi = {10.1096/fj.201801625R}, pages = {5168 -- 5180}, year = {2019}, language = {en} } @inproceedings{CarzanaDachwaldNoomen2017, author = {Carzana, Livio and Dachwald, Bernd and Noomen, Ron}, title = {Model and trajectory optimization for an ideal laser-enhanced solar sail}, series = {68th International Astronautical Congress}, booktitle = {68th International Astronautical Congress}, year = {2017}, abstract = {A laser-enhanced solar sail is a solar sail that is not solely propelled by solar radiation but additionally by a laser beam that illuminates the sail. This way, the propulsive acceleration of the sail results from the combined action of the solar and the laser radiation pressure onto the sail. The potential source of the laser beam is a laser satellite that coverts solar power (in the inner solar system) or nuclear power (in the outer solar system) into laser power. Such a laser satellite (or many of them) can orbit anywhere in the solar system and its optimal orbit (or their optimal orbits) for a given mission is a subject for future research. This contribution provides the model for an ideal laser-enhanced solar sail and investigates how a laser can enhance the thrusting capability of such a sail. The term "ideal" means that the solar sail is assumed to be perfectly reflecting and that the laser beam is assumed to have a constant areal power density over the whole sail area. Since a laser beam has a limited divergence, it can provide radiation pressure at much larger solar distances and increase the radiation pressure force into the desired direction. Therefore, laser-enhanced solar sails may make missions feasible, that would otherwise have prohibitively long flight times, e.g. rendezvous missions in the outer solar system. This contribution will also analyze exemplary mission scenarios and present optimial trajectories without laying too much emphasis on the design and operations of the laser satellites. If the mission studies conclude that laser-enhanced solar sails would have advantages with respect to "traditional" solar sails, a detailed study of the laser satellites and the whole system architecture would be the second next step}, language = {en} } @article{CehreliAkpinarTemizArtmannetal.2015, author = {Cehreli, Ruksan and Akpinar, Hale and Temiz Artmann, Ayseg{\"u}l and Sagol, Ozgul}, title = {Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis}, series = {Gastroenterology Research}, volume = {8}, journal = {Gastroenterology Research}, number = {5}, issn = {1918-2813}, doi = {10.14740/gr683w}, pages = {265 -- 273}, year = {2015}, language = {en} } @article{ChloeMalyaranCraveiroetal.2022, author = {Chlo{\´e}, Radermacher and Malyaran, Hanna and Craveiro, Rogerio Bastos and Peglow, Sarah and Behbahani, Mehdi and Pufe, Thomas and Wolf, Michael and Neuss, Sabine}, title = {Mechanical loading on cementoblasts: a mini review}, series = {Osteologie}, volume = {31}, journal = {Osteologie}, number = {2}, publisher = {Thieme}, address = {Stuttgart}, issn = {1019-1291}, doi = {10.1055/a-1826-0777}, pages = {111 -- 118}, year = {2022}, abstract = {Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments.}, language = {en} } @article{CiobanuStaatRahimi2008, author = {Ciobanu, Octavian and Staat, Manfred and Rahimi, Alireza}, title = {The use of open source software in biomechanical finite element analysis}, series = {Buletinul Institutului Politehnic din Ia{\c{s}}i / Universitatea Tehnică Gh. Asachi, Ia{\c{s}}i Secţia 5, Construcţii de ma{\c{s}}ini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta}, volume = {54}, journal = {Buletinul Institutului Politehnic din Ia{\c{s}}i / Universitatea Tehnică Gh. Asachi, Ia{\c{s}}i Secţia 5, Construcţii de ma{\c{s}}ini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta}, number = {7/8}, issn = {1011-2855}, pages = {213 -- 220}, year = {2008}, language = {en} } @article{CiritsisHorbachStaatetal.2018, author = {Ciritsis, Alexander and Horbach, Andreas and Staat, Manfred and Kuhl, Christiane K. and Kraemer, Nils Andreas}, title = {Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo}, series = {Journal of Biomedical Materials Research: Part B: Applied Biomaterials}, volume = {106}, journal = {Journal of Biomedical Materials Research: Part B: Applied Biomaterials}, number = {2}, publisher = {Wiley}, address = {New York, NY}, issn = {1552-4981}, doi = {10.1002/jbm.b.33877}, pages = {827 -- 833}, year = {2018}, abstract = {Purpose In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model. Material and Methods Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio). Results In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4\% for TPU and of 1.2\% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF. Conclusion The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827-833, 2018.}, language = {en} } @article{ColomboDriraFrotscheretal.2022, author = {Colombo, Daniele and Drira, Slah and Frotscher, Ralf and Staat, Manfred}, title = {An element-based formulation for ES-FEM and FS-FEM models for implementation in standard solid mechanics finite element codes for 2D and 3D static analysis}, series = {International Journal for Numerical Methods in Engineering}, volume = {124}, journal = {International Journal for Numerical Methods in Engineering}, number = {2}, publisher = {Wiley}, address = {Chichester}, issn = {1097-0207}, doi = {10.1002/nme.7126}, pages = {402 -- 433}, year = {2022}, abstract = {Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element.}, language = {en} }