@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{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{ErbayraktarYilmazTemizArtmannetal.2007, author = {Erbayraktar, Zubeyde and Yilmaz, Osman and Temiz Artmann, Ayseg{\"u}l and Cehreli, Ruksan and Coker, Canan}, title = {Effects of Selenium Supplementation on Antioxidant Defense and Glucose Homeostasis in Experimental Diabetes Mellitus}, series = {Biological Trace Element Research}, volume = {118}, journal = {Biological Trace Element Research}, number = {3}, issn = {1559-0720}, pages = {217 -- 226}, year = {2007}, language = {en} } @inproceedings{DigelTemizArtmannNojimaetal.2003, author = {Digel, Ilya and Temiz Artmann, Ayseg{\"u}l and Nojima, H. and Artmann, Gerhard}, title = {Effects of plasma generated ions on bacteria : [poster]}, year = {2003}, abstract = {Summary and Conclusions PCIs were clearly effective in terms of their antibacterial effects with the strains tested. This efficacy increased with the time the bacteries were exposed to PCIs. The bactericidal action has proved to be irreversible. PCIs were significantly less effective in shadowed areas. PCI exposure caused multiple protein damages as observed in SDS PAGE studies. There was no single but multiple molecular mechanism causing the bacterial death.}, subject = {Clusterion}, language = {en} } @inproceedings{SchlemmerPorstBassametal.2017, author = {Schlemmer, Katharina and Porst, Dariusz and Bassam, Rasha and Artmann, Gerhard and Digel, Ilya}, title = {Effects of nitric oxide (NO) and ATP on red blood cell phenotype and deformability}, 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 = {100 -- 101}, year = {2017}, 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} } @inproceedings{FrotscherRaatschenStaat2012, author = {Frotscher, Ralf and Raatschen, Hans-J{\"u}rgen and Staat, Manfred}, title = {Effectiveness of the edge-based smoothed finite element method applied to soft biological tissues}, series = {ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012}, booktitle = {ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012}, editor = {Holzapfel, Gerhard A.}, publisher = {Verlag d. Technischen Universit{\"a}t Graz}, address = {Graz}, isbn = {978-3-85125-223-1}, year = {2012}, language = {en} } @inproceedings{JungStaatMueller2016, author = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram}, title = {Effect of wind on flight style optimisation in ski jumping}, series = {15th International Symposium on Computer Simulation in Biomechanics ; July 9th-11th 2015, Edinburgh, UK}, booktitle = {15th International Symposium on Computer Simulation in Biomechanics ; July 9th-11th 2015, Edinburgh, UK}, publisher = {The University of Edinburgh ; Loughborough University}, address = {Edinburgh}, pages = {53 -- 54}, year = {2016}, language = {en} } @article{WerkhausenAlbrachtCroninetal.2018, author = {Werkhausen, Amelie and Albracht, Kirsten and Cronin, Neil J and Paulsen, G{\o}ran and Bojsen-M{\o}ller, Jens and Seynnes, Olivier R}, title = {Effect of training-induced changes in achilles tendon stiffness on muscle-tendon behavior during landing}, series = {Frontiers in physiology}, journal = {Frontiers in physiology}, number = {9}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2018.00794}, pages = {11 Seiten}, year = {2018}, abstract = {During rapid deceleration of the body, tendons buffer part of the elongation of the muscle-tendon unit (MTU), enabling safe energy dissipation via eccentric muscle contraction. Yet, the influence of changes in tendon stiffness within the physiological range upon these lengthening contractions is unknown. This study aimed to examine the effect of training-induced stiffening of the Achilles tendon on triceps surae muscle-tendon behavior during a landing task. Twenty-one male subjects were assigned to either a 10-week resistance-training program consisting of single-leg isometric plantarflexion (n = 11) or to a non-training control group (n = 10). Before and after the training period, plantarflexion force, peak Achilles tendon strain and stiffness were measured during isometric contractions, using a combination of dynamometry, ultrasound and kinematics data. Additionally, testing included a step-landing task, during which joint mechanics and lengths of gastrocnemius and soleus fascicles, Achilles tendon, and MTU were determined using synchronized ultrasound, kinematics and kinetics data collection. After training, plantarflexion strength and Achilles tendon stiffness increased (15 and 18\%, respectively), and tendon strain during landing remained similar. Likewise, lengthening and negative work produced by the gastrocnemius MTU did not change detectably. However, in the training group, gastrocnemius fascicle length was offset (8\%) to a longer length at touch down and, surprisingly, fascicle lengthening and velocity were reduced by 27 and 21\%, respectively. These changes were not observed for soleus fascicles when accounting for variation in task execution between tests. These results indicate that a training-induced increase in tendon stiffness does not noticeably affect the buffering action of the tendon when the MTU is rapidly stretched. Reductions in gastrocnemius fascicle lengthening and lengthening velocity during landing occurred independently from tendon strain. Future studies are required to provide insight into the mechanisms underpinning these observations and their influence on energy dissipation.}, 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} } @inproceedings{ElBashirDigel2009, author = {ElBashir, Rasha and Digel, Ilya}, title = {Effect of nitric oxide gas on hydrogels : [abstract]}, year = {2009}, abstract = {The results support our theory that the NO gas has an influence in increasing the translational diffusion of hydrogels and it accelerates the melting process of the gels.}, subject = {Stickstoffmonoxid}, language = {en} } @article{KotliarMaierBaueretal.2007, author = {Kotliar, Konstantin and Maier, Mathias and Bauer, Svetlana and Feucht, Nikolaus}, title = {Effect of intravitreal injections and volume changes on intraocular pressure: clinical results and biomechanical model / Kotliar, Konstantin ; Maier, Mathias ; Bauer, Svetlana ; Feucht, Nikolaus ; Lohmann, Chris ; Lanzl, Ines}, series = {Acta Ophthalmologica Scandinavica. 85 (2007), H. 7}, journal = {Acta Ophthalmologica Scandinavica. 85 (2007), H. 7}, publisher = {-}, isbn = {1755-3768}, pages = {777 -- 781}, year = {2007}, language = {en} } @inproceedings{SchmitzApandiSpillneretal.2024, author = {Schmitz, Annika and Apandi, Shah Eiman Amzar Shah and Spillner, Jan and Hima, Flutura and Behbahani, Mehdi}, title = {Effect of different cannula positions in the pulmonary artery on blood flow and gas exchange using computational fluid dynamics analysis}, series = {4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen}, booktitle = {4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen}, editor = {Digel, Ilya and Staat, Manfred and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-65-3}, doi = {10.17185/duepublico/81475}, pages = {29 -- 30}, year = {2024}, abstract = {Pulmonary arterial cannulation is a common and effective method for percutaneous mechanical circulatory support for concurrent right heart and respiratory failure [1]. However, limited data exists to what effect the positioning of the cannula has on the oxygen perfusion throughout the pulmonary artery (PA). This study aims to evaluate, using computational fluid dynamics (CFD), the effect of different cannula positions in the PA with respect to the oxygenation of the different branching vessels in order for an optimal cannula position to be determined. The four chosen different positions (see Fig. 1) of the cannulas are, in the lower part of the main pulmonary artery (MPA), in the MPA at the junction between the right pulmonary artery (RPA) and the left pulmonary artery (LPA), in the RPA at the first branch of the RPA and in the LPA at the first branch of the LPA.}, language = {en} } @article{PogorelovaRogachevAkimbekovetal.2024, author = {Pogorelova, Natalia and Rogachev, Evgeniy and Akimbekov, Nuraly and Digel, Ilya}, title = {Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates}, series = {Journal of materials science}, volume = {2024}, journal = {Journal of materials science}, publisher = {Springer Science + Business Media}, address = {Dordrecht}, issn = {1573-4803 (Online)}, doi = {10.1007/s10853-024-09596-3}, pages = {13 Seiten}, year = {2024}, abstract = {Many important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1\%, dried until a constant weight was reached) and freeze-drying (FD, treated at - 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity.}, language = {en} } @article{KotliarMueckeVilseretal.2008, author = {Kotliar, Konstantin and M{\"u}cke, Bruno and Vilser, Walthard and Schilling, Rudolf}, title = {Effect of aging on retinal artery blood column diameter measured along the vessel axis / Kotliar, Konstantin E. ; M{\"u}cke, Bruno ; Vilser, Walthard ; Schilling, Rudolf ; Lanzl, Ines M.}, series = {Investigative Ophthalmology \& Visual Science, IOVS. 49 (2008), H. 5}, journal = {Investigative Ophthalmology \& Visual Science, IOVS. 49 (2008), H. 5}, publisher = {-}, isbn = {0146-0404}, pages = {2094 -- 2102}, year = {2008}, language = {en} } @inproceedings{SherelkhanAlibekova2024, author = {Sherelkhan, Dinara and Alibekova, Alina}, title = {EEM spectroscopy characterization of humic substances of biomedical importance}, series = {4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen}, booktitle = {4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen}, editor = {Digel, Ilya and Staat, Manfred and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-65-3}, doi = {10.17185/duepublico/81475}, pages = {31 -- 32}, year = {2024}, abstract = {Humic substances possess distinctive chemical features enabling their use in many advanced applications, including biomedical fields. No chemicals in nature have the same combination of specific chemical and biological properties as humic substances. Traditional medicine and modern research have demonstrated that humic substances from different sources possess immunomodulatory and anti-inflammatory properties, which makes them suitable for the prevention and treatment of chronic dermatoses, allergic rhinitis, atopic dermatitis, and other conditions characterized by inflammatory and allergic responses [1-4]. The use of humic compounds as agentswith antifungal and antiviral properties shows great potential [5-7].}, language = {en} } @inproceedings{MandekarJentschLutzetal.2021, author = {Mandekar, Swati and Jentsch, Lina and Lutz, Kai and Behbahani, Mehdi and Melnykowycz, Mark}, title = {Earable design analysis for sleep EEG measurements}, series = {UbiComp '21}, booktitle = {UbiComp '21}, doi = {10.1145/3460418.3479328}, pages = {171 -- 175}, year = {2021}, abstract = {Conventional EEG devices cannot be used in everyday life and hence, past decade research has been focused on Ear-EEG for mobile, at-home monitoring for various applications ranging from emotion detection to sleep monitoring. As the area available for electrode contact in the ear is limited, the electrode size and location play a vital role for an Ear-EEG system. In this investigation, we present a quantitative study of ear-electrodes with two electrode sizes at different locations in a wet and dry configuration. Electrode impedance scales inversely with size and ranges from 450 kΩ to 1.29 MΩ for dry and from 22 kΩ to 42 kΩ for wet contact at 10 Hz. For any size, the location in the ear canal with the lowest impedance is ELE (Left Ear Superior), presumably due to increased contact pressure caused by the outer-ear anatomy. The results can be used to optimize signal pickup and SNR for specific applications. We demonstrate this by recording sleep spindles during sleep onset with high quality (5.27 μVrms).}, language = {en} } @article{HauserKotliarTholenetal.2015, author = {Hauser, C. and Kotliar, Konstantin and Tholen, S. and Hasenau, A. and Suttmann, Y. and Renders, L. and Heemann, U. and Baumann, M. and Schmaderer, C.}, title = {Dynamische retinale Gef{\"a}ßreaktion bei H{\"a}modialysepatienten}, series = {Nieren- und Hochdruckkrankheiten}, volume = {44}, journal = {Nieren- und Hochdruckkrankheiten}, number = {11}, publisher = {Dustri-Verlag}, address = {Oberhaching}, issn = {0300-5224}, doi = {10.5414/NHX01743a}, pages = {480 -- 480}, year = {2015}, language = {de} } @phdthesis{Kotliar2013, author = {Kotliar, Konstantin}, title = {Dynamische retinale Gef{\"a}ßanalyse f{\"u}r die Diagnostik und Fr{\"u}herkennung von System- und Augenerkrankungen vaskul{\"a}rer Genese}, pages = {128 Bl.}, year = {2013}, language = {de} } @article{AimenovaDigelEshibaev2016, author = {Aimenova, Zh. E. and Digel, Ilya and Eshibaev, А. А.}, title = {Dynamics of accumulation of lagochirzin in Lagochilus setulosus phytomass during the growing season and also features of its cultivation in the conditions of a typical sierozem}, series = {KazNU Bulletin. Biology series}, volume = {69}, journal = {KazNU Bulletin. Biology series}, number = {4}, publisher = {Al-Farabi Kazakh National University}, address = {Almaty}, issn = {1563-0218}, pages = {4 -- 11}, year = {2016}, abstract = {L.setulosus is offered for creation of biopreparation «Setulin», possesing he- mostatic action, the basic reactant of biopreparation is diterpen - lagochirzin. Results under the maintenance and dynamics of diterpen lagochirzin accumula- tion in various parts of L.setulosus are presented: in roots, stalks, leaves, flowers and calyx lobes during the growing season, and also results on conditions of cultivation L.setulosus in the conditions of a typical sierozem are resulted. From the obtained data is visible, that the given species of a plant is endemic. It is established, that dynamics of accumulation of lagochirzin in phytomass accrues from the beginning to the middle of the growing season. The chemical analysis of L.setulosus on a localization of lagochirzin in various organs of a plant, has shown, that the greatest quantity of lagochirzin collects in calyx lobes of the plants. Also it is established, that L.setulosus can be cultivated in the conditions of the typical sierozem, a mineral food is necessary for the given species of plants of Lagochilus genus, except nitric fertilizers. Comparative studying of wild-growing and cultural forms of L.setulosus has shown, that in the cultivated phytomass of plants the maintenance of lagochirzin on 17-20 \% higher than in the wild-growing species.}, language = {en} } @article{StadlerZerlinDigeletal.2008, author = {Stadler, Andreas M. and Zerlin, Kay and Digel, Ilya and B{\"u}ldt, Georg and Zaccai, Guiseppe and Artmann, Gerhard}, title = {Dynamics and interactions of hemoglobin in red blood cells}, series = {Tissue Engineering Part A. 14 (2008), H. 5}, journal = {Tissue Engineering Part A. 14 (2008), H. 5}, isbn = {1937-3341}, pages = {724 -- 724}, year = {2008}, language = {en} } @article{ZerlinDigelStadleretal.2007, author = {Zerlin, Kay and Digel, Ilya and Stadler, Andreas M. and B{\"u}ldt, Georg and Zaccai, Guiseppe and Artmann, Gerhard}, title = {Dynamics and interactions of hemoglobin in human red blood cells and concentrated hemoglobin solutions}, series = {Regenerative medicine. 2 (2007), H. 5}, journal = {Regenerative medicine. 2 (2007), H. 5}, isbn = {1746-0751}, pages = {573 -- 573}, year = {2007}, language = {en} } @article{KotliarLanzlSchmidtTrucksaessetal.2011, author = {Kotliar, Konstantin and Lanzl, Ines M. and Schmidt-Trucks{\"a}ss, A. and Sitnikova, Diana and Ali, Mohammad and Blume, Katharina and Halle, Martin and Hansser, Henner}, title = {Dynamic retinal vessel response to flicker in obesity: A methodological approach}, series = {Microvascular Research}, volume = {81}, journal = {Microvascular Research}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0026-2862}, pages = {123 -- 128}, year = {2011}, language = {en} } @article{LanzlSeidovaMaieretal.2011, author = {Lanzl, Ines M. and Seidova, Seid-Fatima and Maier, Mathias and Schmidt-Trucks{\"a}ss, Arno and Halle, Martin and Kotliar, Konstantin}, title = {Dynamic retinal vessel response to flicker in age-related macular degeneration patients before and after vascular endothelial growth factor inhibitor injection}, series = {Acta Ophthalmologica}, volume = {89}, journal = {Acta Ophthalmologica}, number = {5}, publisher = {Wiley}, address = {Weinheim}, isbn = {1755-3768}, pages = {472 -- 479}, year = {2011}, language = {en} } @article{WegmannHacklStaatetal.2016, author = {Wegmann, Kilian and Hackl, Michael and Staat, Manfred and Mayer, Katharina and M{\"u}ller, Lars-Peter}, title = {Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results}, series = {Knee surgery, sports traumatology, arthroscopy}, volume = {Volume 24}, journal = {Knee surgery, sports traumatology, arthroscopy}, number = {Supplement 1}, publisher = {Springer}, address = {Berlin}, issn = {0942-2056}, doi = {10.1007/s00167-016-4079-0}, pages = {58 -- 59}, year = {2016}, abstract = {While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates.}, language = {en} } @article{KotliarKharoubiSchmidtTrucksaessetal.2009, author = {Kotliar, Konstantin and Kharoubi, A. and Schmidt-Trucks{\"a}ß, A. and Halle, M. and Lanzl, I.}, title = {Does internal longitudinal microstructure of retinal veins change with age in medically healthy persons?}, series = {Acta Ophthalmologica}, volume = {Vol. 87}, journal = {Acta Ophthalmologica}, number = {Suppl. S244}, publisher = {Wiley}, address = {Weinheim}, issn = {1600-0420 (E-Journal); 1755-3768 (E-Journal); 0001-639X (Print); 1395-3907 (Print); 1755-375X (Print)}, pages = {0}, year = {2009}, language = {en} } @article{KotliarLanzlHanssenetal.2012, author = {Kotliar, Konstantin and Lanzl, Ines M. and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Halle, Martin and Heemann, Uwe and Schmidt-Trucks{\"a}ss, Arno and Baumann, Marcus}, title = {Does increased blood pressure rather than aging influence retinal pulse wave velocity?}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {53}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.11-8815}, pages = {2119 -- 2126}, year = {2012}, abstract = {Purpose: It was demonstrated previously that retinal pulse wave velocity (rPWV) as a measure of retinal arterial stiffness is increased in aged anamnestically healthy volunteers compared with young healthy subjects. Using novel methodology of rPWV assessment this finding was confirmed and investigated whether it might relate to the increased blood pressure usually accompanying the aging process, rather than to the aging itself. Methods: A total of 12 young 25.5-year-old (24.0-28.8) [median(1st quartile-3rd quartile)] and 12 senior 68.5-year-old (63.8-71.8) anamnestically healthy volunteers; and 12 senior 63.0-year-old (60.8-65.0) validated healthy volunteers and 12 young 33.0-year-old (29.5-35.0) hypertensive patients were examined. Time-dependent alterations of vessel diameter were assessed by the Dynamic Vessel Analyzer in a retinal artery of each subject. The data were filtered and processed using mathematical signal analysis and rPWVs were calculated. Results: rPWV amounted to 1200 (990-1470) RU (relative units)/s in the hypertensive group and to 1040 (700-2230) RU/s in anamnestically healthy seniors. These differed significantly from rPWVs in young healthy group (410 [280-500] RU/s) and in validated healthy seniors (400 [320-510] RU/s). rPWV associated with age and mean arterial pressure (MAP) in the pooled cohort excluded validated healthy seniors. In a regression model these associations remain when alternately adjusted for MAP and age. When including validated healthy seniors in the pooled cohort only association with MAP remains. Conclusions: Both aging (with not excluded cardiovascular risk factors) and mild hypertension are associated with elevated rPWV. rPWV increases to a similar extent both in young mildly hypertensive subjects and in aged anamnestically healthy persons. Healthy aging is not associated with increased rPWV.}, language = {en} } @inproceedings{SuryoputriGhaderiLinderetal.2017, author = {Suryoputri, Nathania and Ghaderi, Aydin and Linder, Peter and Kotliar, Konstantin and G{\"o}ttler, Jens and Sorg, Christian and Grimmer, Timo}, title = {Does hemodynamic response function change in Alzheimer disease?}, 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 = {92}, year = {2017}, language = {en} } @article{KuertenKotliarFuestetal.2021, author = {Kuerten, David and Kotliar, Konstantin and Fuest, Matthias and Walter, Peter and Hollstein, Muriel and Plange, Niklas}, title = {Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study}, series = {International Ophthalmology}, volume = {41}, journal = {International Ophthalmology}, number = {41}, editor = {Neri, Piergiorgio}, publisher = {Springer}, address = {Berlin}, isbn = {1573-2630}, doi = {10.1007/s10792-021-01876-0}, pages = {3109 -- 3119}, year = {2021}, abstract = {Purpose Vascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry. Methods 15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (-20.99 ± 10.49 pro- found hemispheric visual field defect vs -7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye. Results Significant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p \ 0.04 and p \ 0.02 respectively) in-between the hemispheres spheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance. Conclusion Localized retinal vessel regulation is significantly altered in glaucoma patients with asymmetri altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect.}, language = {en} } @article{TemizArtmannKayatekinUysaletal.2005, author = {Temiz Artmann, Ayseg{\"u}l and Kayatekin, Muammer B. and Uysal, N. and Resmi, H.}, title = {Does antioxidant supplementation alter the effects of acute exercise on erythrocyte aggregation, deformability and endothelium adhesion in untrained rats? Kayatekin, Muammer B.; Uysal N.; Resmi, H.; Bediz, Seref C.; Temiz Artmann, A.; Gen{\c{c}}, S.; Tugyan, K.}, series = {International Journal for Vitamin and Nutrition Research. 75 (2005), H. 4}, journal = {International Journal for Vitamin and Nutrition Research. 75 (2005), H. 4}, isbn = {0300-9831}, pages = {243 -- 250}, year = {2005}, language = {en} } @article{WerkhausenCroninAlbrachtetal.2019, author = {Werkhausen, Amelie and Cronin, Neil J. and Albracht, Kirsten and Bojsen-M{\o}ller, Jens and Seynnes, Olivier R.}, title = {Distinct muscle-tendon interaction during running at different speeds and in different loading conditions}, series = {Journal of Applied Physiology}, volume = {127}, journal = {Journal of Applied Physiology}, number = {1}, issn = {1522-1601}, doi = {10.1152/japplphysiol.00710.2018}, pages = {246 -- 253}, year = {2019}, language = {en} } @article{ZhenLiangStaatetal.2024, author = {Zhen, Manghao and Liang, Yunpei and Staat, Manfred and Li, Quanqui and Li, Jianbo}, title = {Discontinuous fracture behaviors and constitutive model of sandstone specimens containing non-parallel prefabricated fissures under uniaxial compression}, series = {Theoretical and Applied Fracture Mechanics}, volume = {131}, journal = {Theoretical and Applied Fracture Mechanics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-8442}, doi = {10.1016/j.tafmec.2024.104373}, pages = {Artikel 104373}, year = {2024}, abstract = {The deformation and damage laws of non-homogeneous irregular structural planes in rocks are the basis for studying the stability of rock engineering. To investigate the damage characteristics of rock containing non-parallel fissures, uniaxial compression tests and numerical simulations were conducted on sandstone specimens containing three non-parallel fissures inclined at 0°, 45° and 90° in this study. The characteristics of crack initiation and crack evolution of fissures with different inclinations were analyzed. A constitutive model for the discontinuous fractures of fissured sandstone was proposed. The results show that the fracture behaviors of fissured sandstone specimens are discontinuous. The stress-strain curves are non-smooth and can be divided into nonlinear crack closure stage, linear elastic stage, plastic stage and brittle failure stage, of which the plastic stage contains discontinuous stress drops. During the uniaxial compression test, the middle or ends of 0° fissures were the first to crack compared to 45° and 90° fissures. The end with small distance between 0° and 45° fissures cracked first, and the end with large distance cracked later. After the final failure, 0° fissures in all specimens were fractured, while 45° and 90° fissures were not necessarily fractured. Numerical simulation results show that the concentration of compressive stress at the tips of 0°, 45° and 90° fissures, as well as the concentration of tensile stress on both sides, decreased with the increase of the inclination angle. A constitutive model for the discontinuous fractures of fissured sandstone specimens was derived by combining the logistic model and damage mechanic theory. This model can well describe the discontinuous drops of stress and agrees well with the whole processes of the stress-strain curves of the fissured sandstone specimens.}, language = {en} } @article{TranStaat2021, author = {Tran, Ngoc Trinh and Staat, Manfred}, title = {Direct plastic structural design under random strength and random load by chance constrained programming}, series = {European Journal of Mechanics - A/Solids}, volume = {85}, journal = {European Journal of Mechanics - A/Solids}, number = {Article 104106}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0997-7538}, doi = {10.1016/j.euromechsol.2020.104106}, year = {2021}, language = {en} } @article{TranStaat2020, author = {Tran, Ngoc Trinh and Staat, Manfred}, title = {Direct plastic structural design under lognormally distributed strength by chance constrained programming}, series = {Optimization and Engineering}, volume = {21}, journal = {Optimization and Engineering}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {1573-2924}, doi = {10.1007/s11081-019-09437-2}, pages = {131 -- 157}, year = {2020}, abstract = {We propose the so-called chance constrained programming model of stochastic programming theory to analyze limit and shakedown loads of structures under random strength with a lognormal distribution. A dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) is used with three-node linear triangular elements.}, language = {en} } @inproceedings{TranMatthiesStavroulakisetal.2018, author = {Tran, Ngoc Trinh and Matthies, Hermann G. and Stavroulakis, Georgios Eleftherios and Staat, Manfred}, title = {Direct plastic structural design by chance constrained programming}, series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, pages = {12 Seiten}, year = {2018}, abstract = {We propose a stochastic programming method to analyse limit and shakedown of structures under random strength with lognormal distribution. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit or the shakedown limit. The edge-based smoothed finite element method (ES-FEM) using three-node linear triangular elements is used.}, language = {en} } @article{StaatHeitzerLangetal.2005, author = {Staat, Manfred and Heitzer, M. and Lang, H. and Wirtz, K.}, title = {Direct Finite Element Route for Design-by-Analysis of Pressure Components}, series = {International Journal of Pressure Vessels and Piping. 82 (2005), H. 1}, journal = {International Journal of Pressure Vessels and Piping. 82 (2005), H. 1}, isbn = {0308-0161}, pages = {61 -- 67}, year = {2005}, language = {en} } @article{Staat2005, author = {Staat, Manfred}, title = {Direct finite element route for design-by-analysis of pressure components}, year = {2005}, abstract = {In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion.}, subject = {Einspielen }, language = {en} } @article{LanzlSeidovaErbenetal.2010, author = {Lanzl, Ines M. and Seidova, Seid-Fatima and Erben, A. and Th{\"u}rmel, K. and Kotliar, Konstantin}, title = {Diffuse stromale Hornhauttr{\"u}bungen und Ver{\"a}nderungen der H{\"a}nde}, series = {Der Ophthalmologe}, volume = {107}, journal = {Der Ophthalmologe}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1433-0423}, doi = {10.1007/s00347-009-2066-2}, pages = {363 -- 365}, year = {2010}, abstract = {Bilaterale stromale Hornhauttr{\"u}bungen sind f{\"u}r den Augenarzt eine differenzialdiagnostische Herausforderung. Im folgenden Beitrag werden 2 Patieninnen (30 und 36 Jahre) mit unterschiedlich stark ausgepr{\"a}gter stromaler diffuser Hornhauttr{\"u}bung vorgestellt. Patientin 1 war kleinw{\"u}chsig (114 cm) und Patientin 2 normal groß (172 cm). Beide Patientinnen wiesen ver{\"a}nderte Gelenkstrukturen an Hand und Fußgelenken sowie diffuse stromale Hornhauttr{\"u}bungen auf. Des Weiteren lagen eine Mitral- und Aorteninsuffizienz (Patientin 1) bzw. eine Aorteninsuffizienz (Patientin 2) vor. Die stromalen diffusen Hornhauttr{\"u}bungen ließen im Zusammenhang mit den Gelenkver{\"a}nderungen ein Scheie-Syndrom vermuten. Therapeutisch ist bei Patienten mit Visusminderung eine (lamell{\"a}re) Keratoplastik sinnvoll.}, language = {de} } @article{HeinzelSchaeferMuelleretal.2010, author = {Heinzel, Alexander and Sch{\"a}fer, Ralf and M{\"u}ller, Hans-Wilhelm and Schieffer, Andre and Ingenhag, Ariane and Northoff, Georg and Franz, Matthias and Hautzel, Hubertus}, title = {Differential modulation of valence and arousal in high-alexithymic and low-alexithymic individuals}, series = {Neuroreport}, volume = {21}, journal = {Neuroreport}, number = {15}, publisher = {Lippincott Williams \& Wilkins}, address = {London}, issn = {1473-558X}, doi = {10.1097/WNR.0b013e32833f38e0}, pages = {998 -- 1002}, year = {2010}, abstract = {High-alexithymic individuals are characterized by an impaired ability to identify and communicate emotions whereas low-alexithymic individuals have a wide-ranging ability to deal with emotions. This study examined the hypothesis that valence and arousal modifications of emotional stimuli differentially modulate cortical regions in high-alexithymic and low-alexithymic individuals. To this end, 28 high-alexithymic and 25 low-alexithymic individuals were investigated with event-related fMRI using visual emotional stimuli. We found differential neural activations in the dorsal anterior cingulate, the insula and the amygdala. We suggest that these differences may account for the impaired ability of high-alexithymic individuals to appropriately handle emotional stimuli.}, language = {en} } @inproceedings{DroszezSannoGoldmannetal.2016, author = {Droszez, Anna and Sanno, Maximilian and Goldmann, Jan-Peter and Albracht, Kirsten and Br{\"u}ggemann, Gerd-Peter and Braunstein, Bjoern}, title = {Differences between take-off behavior during vertical jumps and two artistic elements}, series = {34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016}, booktitle = {34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016}, issn = {1999-4168}, pages = {577 -- 580}, year = {2016}, language = {en} } @inproceedings{HunkerJungGossmannetal.2019, author = {Hunker, Jan and Jung, Alexander and Goßmann, Matthias and Linder, Peter and Staat, Manfred}, title = {Development of a tool to analyze the conduction speed in microelectrode array measurements of cardiac tissue}, 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 = {7 -- 8}, year = {2019}, abstract = {The discovery of human induced pluripotent stem cells reprogrammed from somatic cells [1] and their ability to differentiate into cardiomyocytes (hiPSC-CMs) has provided a robust platform for drug screening [2]. Drug screenings are essential in the development of new components, particularly for evaluating the potential of drugs to induce life-threatening pro-arrhythmias. Between 1988 and 2009, 14 drugs have been removed from the market for this reason [3]. The microelectrode array (MEA) technique is a robust tool for drug screening as it detects the field potentials (FPs) for the entire cell culture. Furthermore, the propagation of the field potential can be examined on an electrode basis. To analyze MEA measurements in detail, we have developed an open-source tool.}, 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} } @article{SeifarthGossmannGrosseetal.2015, author = {Seifarth, Volker and Goßmann, Matthias and Grosse, J. O. and Becker, C. and Heschel, I. and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Development of a Bioreactor to Culture Tissue Engineered Ureters Based on the Application of Tubular OPTIMAIX 3D Scaffolds}, series = {Urologia Internationalis}, volume = {2015}, journal = {Urologia Internationalis}, number = {95}, publisher = {Karger}, address = {Basel}, issn = {0042-1138}, doi = {10.1159/000368419}, pages = {106 -- 113}, year = {2015}, language = {en} } @inproceedings{SchneiderAlHakimKayseretal.2017, author = {Schneider, Oliver and Al Hakim, Taher and Kayser, Peter and Digel, Ilya}, title = {Development and trials of a test chamber for ultrasound-assisted sampling of living cells from solid surfaces}, 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 = {96 -- 97}, year = {2017}, language = {en} } @inproceedings{DachwaldXuFeldmannetal.2011, author = {Dachwald, Bernd and Xu, Changsheng and Feldmann, Marco and Plescher, Engelbert and Digel, Ilya and Artmann, Gerhard}, title = {Development and testing of a subsurface probe for detection of life in deep ice : [abstract]}, year = {2011}, abstract = {We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named "IceMole", is currently developed, built, and tested at the FH Aachen University of Applied Sciences' Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).}, subject = {Eisschicht}, language = {en} } @article{KraemerDaabMuelleretal.2013, author = {Kr{\"a}mer, Stefan and Daab, Dominique Jonas and M{\"u}ller, Brigitte and Wagner, Tobias and Baader, Fabian and Hessel, Joana and Gdalewitsch, Georg and Plescher, Engelbert and Dachwald, Bernd and Wahle, Michael and Gierse, Andreas and Vetter, Rudolf and Pf{\"u}tzenreuter, Lysan}, title = {Development and flight-testing of a system to isolate vibrations for microgravity experiments on sounding rockets}, series = {21st ESA Symposium on Rocket and Balloon Research}, journal = {21st ESA Symposium on Rocket and Balloon Research}, pages = {1 -- 8}, year = {2013}, language = {en} } @article{HasanKeilStaatetal.2012, author = {Hasan, Istabrak and Keil, Ludger and Staat, Manfred and Wahl, Gerhard and Bourauel, Christoph}, title = {Determination of the frictional coefficient of the implant-antler interface : experimental approach}, series = {Biomedical Engineering / Biomedizinische Technik}, volume = {57}, journal = {Biomedical Engineering / Biomedizinische Technik}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {1862-278X}, pages = {359 -- 363}, year = {2012}, abstract = {The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5-0.7 and 0.3-0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens.}, language = {en} } @article{MaggakisKelemenBiselliArtmann2002, author = {Maggakis-Kelemen, Christina and Biselli, Manfred and Artmann, Gerhard}, title = {Determination of the elastic shear modulus of cultured human red blood cells}, series = {Biomedizinische Technik. 47 (2002), H. Suppl. 1 Pt. 1}, journal = {Biomedizinische Technik. 47 (2002), H. Suppl. 1 Pt. 1}, isbn = {0013-5585}, pages = {106 -- 109}, year = {2002}, language = {en} } @article{ZhubanovaMansurovDigeletal.2013, author = {Zhubanova, А. and Mansurov, Z.A. and Digel, Ilya and Saviskaya, I.S. and Akimbekov, N.Sh.}, title = {Designing of Heterogeneous Nanobiocomposites for Biotechnology}, series = {KazNU Bulletin. Biology series}, volume = {59}, journal = {KazNU Bulletin. Biology series}, number = {No 3/1}, isbn = {1563-0218}, pages = {89 -- 93}, year = {2013}, language = {ru} } @inproceedings{DachwaldWurm2009, author = {Dachwald, Bernd and Wurm, P.}, title = {Design concept and modeling of an advanced solar photon thruster}, series = {Advances in the Astronautical Sciences}, booktitle = {Advances in the Astronautical Sciences}, publisher = {American Astronautical Society}, address = {San Diego, Calif.}, isbn = {978-087703554-1}, issn = {00653438}, pages = {723 -- 740}, year = {2009}, abstract = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), holds the potential of providing significant performance advantages over the flat solar sail. Previous SPT design concepts, however, do not consider shadowing effects and multiple reflections of highly concentrated solar radiation that would inevitably destroy the gossamer sail film. In this paper, we propose a novel advanced SPT (ASPT) design concept that does not suffer from these oversimplifications. We present the equations that describe the thrust force acting on such a sail system and compare its performance with respect to the conventional flat solar sail.}, language = {en} }