@article{StadlerGarveyEmbsetal.2014, author = {Stadler, Alexander Maximilian and Garvey, Christopher J. and Embs, Jan Peter and Koza, Michael Marek and Unruh, Tobias and Artmann, Gerhard and Zaccai, Guiseppe}, title = {Picosecond dynamics in haemoglobin from different species: A quasielastic neutron scattering study}, series = {Biochimica et biophysica acta (BBA): General Subjects}, volume = {1840}, journal = {Biochimica et biophysica acta (BBA): General Subjects}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-8006 (E-Journal); 0304-4165 (Print)}, doi = {10.1016/j.bbagen.2014.06.007}, pages = {2989 -- 2999}, year = {2014}, 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{FrotscherStaat2014, author = {Frotscher, Ralf and Staat, Manfred}, title = {Stresses produced by different textile mesh implants in a tissue equivalent}, series = {BioNanoMaterials}, volume = {15}, journal = {BioNanoMaterials}, number = {1-2}, publisher = {De Gruyter}, address = {Berlin}, issn = {2191-4672 (E-Journal); 2193-066X (E-Journal); 0011-8656 (Print); 1616-0177 (Print); 2193-0651 (Print)}, doi = {10.1515/bnm-2014-0003}, pages = {25 -- 30}, year = {2014}, abstract = {Two single-incision mini-slings used for treating urinary incontinence in women are compared with respect to the stresses they produce in their surrounding tissue. In an earlier paper we experimentally observed that these implants produce considerably different stress distributions in a muscle tissue equivalent. Here we perform 2D finite element analyses to compare the shear stresses and normal stresses in the tissue equivalent for the two meshes and to investigate their failure behavior. The results clearly show that the Gynecare TVT fails for increasing loads in a zipper-like manner because it gradually debonds from the surrounding tissue. Contrary to that, the tissue at the ends of the DynaMesh-SIS direct may rupture but only at higher loads. The simulation results are in good agreement with the experimental observations thus the computational model helps to interpret the experimental results and provides a tool for qualitative evaluation of mesh implants.}, language = {en} } @article{KonstantinidisFloresMartinezDachwaldetal.2015, author = {Konstantinidis, Konstantinos and Flores Martinez, Claudio and Dachwald, Bernd and Ohndorf, Andreas and Dykta, Paul and Bowitz, Pascal and Rudolph, Martin and Digel, Ilya and Kowalski, Julia and Voigt, Konstantin and F{\"o}rstner, Roger}, title = {A lander mission to probe subglacial water on Saturn's moon enceladus for life}, series = {Acta astronautica}, volume = {Vol. 106}, journal = {Acta astronautica}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-2030 (E-Journal); 0094-5765 (Print)}, pages = {63 -- 89}, year = {2015}, language = {en} } @article{DachwaldMikuckiTulaczyketal.2014, author = {Dachwald, Bernd and Mikucki, Jill and Tulaczyk, Slawek and Digel, Ilya and Espe, Clemens and Feldmann, Marco and Francke, Gero and Kowalski, Julia and Xu, Changsheng}, title = {IceMole : A maneuverable probe for clean in situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems}, series = {Annals of Glaciology}, volume = {55}, journal = {Annals of Glaciology}, number = {65}, publisher = {Cambridge University Press}, address = {Cambridge}, issn = {1727-5644}, doi = {10.3189/2014AoG65A004}, pages = {14 -- 22}, year = {2014}, abstract = {There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample.}, 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{Staat2004, author = {Staat, Manfred}, title = {Plastic collapse analysis of longitudinally flawed pipes and vessels}, year = {2004}, abstract = {Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data.}, subject = {Druckbeh{\"a}lter}, language = {en} } @article{Staat2005, author = {Staat, Manfred}, title = {Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels}, year = {2005}, abstract = {Limit loads can be calculated with the finite element method (FEM) for any component, defect geometry, and loading. FEM suggests that published long crack limit formulae for axial defects under-estimate the burst pressure for internal surface defects in thick pipes while limit loads are not conservative for deep cracks and for pressure loaded crack-faces. Very deep cracks have a residual strength, which is modelled by a global collapse load. These observations are combined to derive new analytical local and global collapse loads. The global collapse loads are close to FEM limit analyses for all crack dimensions.}, subject = {Finite-Elemente-Methode}, 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{Staat2003, author = {Staat, Manfred}, title = {Shakedown and ratchetting under tension-torsion loadings: analysis and experiments}, year = {2003}, abstract = {Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.}, subject = {Einspielen }, language = {en} } @article{VuStaat2004, author = {Vu, Duc-Khoi and Staat, Manfred}, title = {An algorithm for shakedown analysis of structure with temperature dependent yield stress}, year = {2004}, abstract = {This work is an attempt to answer the question: How to use convex programming in shakedown analysis of structures made of materials with temperature-dependent properties. Based on recently established shakedown theorems and formulations, a dual relationship between upper and lower bounds of the shakedown limit load is found, an algorithmfor shakedown analysis is proposed. While the original problem is neither convex nor concave, the algorithm presented here has the advantage of employing convex programming tools.}, subject = {Einspielen }, language = {en} } @article{KuehnHaugnerStaatetal.2004, author = {K{\"u}hn, Raoul-Roman and Haugner, Werner and Staat, Manfred and Sponagel, Stefan}, title = {A Two Phase Mixture Model based on Bone Observation}, year = {2004}, abstract = {An optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff's law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency.}, subject = {Knochen}, 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} } @article{MartinGonzalezKotliarRiosMartinezetal.2014, author = {Martin-Gonzalez, Anabel and Kotliar, Konstantin and Rios-Martinez, Jorge and Lanzl, Ines and Navab, Nassir}, title = {Mediated-reality magnification for macular degeneration rehabilitation}, series = {Journal of Modern Optics}, volume = {61}, journal = {Journal of Modern Optics}, number = {17}, publisher = {Taylor \& Francis}, address = {London}, issn = {1362-3044}, doi = {10.1080/09500340.2014.936110}, pages = {1400 -- 1408}, year = {2014}, language = {en} } @article{KotliarDrozdovaShamshinova2006, author = {Kotliar, Konstantin and Drozdova, G. A. and Shamshinova, A. M.}, title = {Ocular hemodinamics and contemporary methods of its assessment.
 Part I. Ocular blood circulation and its quantitative estimation}, series = {National journal Glaucoma}, volume = {Vol. 5}, journal = {National journal Glaucoma}, number = {No. 3}, issn = {2078-4104}, pages = {62 -- 73}, year = {2006}, language = {ru} } @article{KotliarLanzl2002, author = {Kotliar, Konstantin and Lanzl, I. M.}, title = {Biomechanical modeling of the aqueous humor outflow after non-penetrating glaucoma filtration surgery in the human eye}, series = {Acta of bioengineering and biomechanics}, volume = {Vol. 4}, journal = {Acta of bioengineering and biomechanics}, number = {Suppl. 1}, issn = {1509-409X}, pages = {728 -- 729}, year = {2002}, language = {de} } @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{KappmeyerKotliarLanzl2009, author = {Kappmeyer, K. and Kotliar, Konstantin and Lanzl, I. M.}, title = {Spielen von Blasinstrumenten und Augeninnendruck}, series = {Zeitschrift f{\"u}r praktische Augenheilkunde \& augen{\"a}rztliche Fortbildung : ZPA}, volume = {Bd. 30}, journal = {Zeitschrift f{\"u}r praktische Augenheilkunde \& augen{\"a}rztliche Fortbildung : ZPA}, issn = {1436-0322}, pages = {169 -- 171}, year = {2009}, language = {de} } @article{KotliarDrozdovaShamshinova2007, author = {Kotliar, Konstantin and Drozdova, G. A. and Shamshinova, A. M.}, title = {Ocular hemodinamics and contemporary methods of its assessment. Part III. Non-invasive methods of assessment of ocular blood flow. 2. Static and dynamic assessment of retinal vessel reaction to stimuli}, series = {National Journal Glaucoma}, volume = {Vol. 6}, journal = {National Journal Glaucoma}, number = {No. 2}, issn = {2078-4104}, pages = {64 -- 71}, year = {2007}, language = {ru} } @article{KotliarDrozdovaShamshinova2007, author = {Kotliar, Konstantin and Drozdova, G. A. and Shamshinova, A. M.}, title = {Ocular hemodinamics and contemporary methods of its assessment. Part III. Non-invasive methods of assessment of ocular blood flow. 1. Assessment of blood cell velocities and flow rates in intraocular vessels and vascular beds}, series = {Journal of Glaucoma}, volume = {Vol. 6}, journal = {Journal of Glaucoma}, number = {1}, issn = {2078-4104}, pages = {61 -- 68}, year = {2007}, language = {ru} } @article{KotliarDrozdovaShamshinova2006, author = {Kotliar, Konstantin and Drozdova, G. A. and Shamshinova, A. M.}, title = {Ocular hemodinamics and contemporary methods of its assessment. Part II. Invasive methods of assessment of ocular blood flow}, series = {National Journal Glaucoma}, volume = {Vol. 5}, journal = {National Journal Glaucoma}, number = {No. 4}, issn = {2078-4104}, pages = {37 -- 49}, year = {2006}, language = {ru} } @article{FrotscherKochStaat2015, author = {Frotscher, Ralf and Koch, Jan-Peter and Staat, Manfred}, title = {Computational investigation of drug action on human-induced stem cell derived cardiomyocytes}, series = {Journal of biomechanical engineering}, volume = {Vol. 137}, journal = {Journal of biomechanical engineering}, number = {iss. 7}, publisher = {ASME}, address = {New York}, issn = {1528-8951 (E-Journal); 0148-0731 (Print)}, doi = {10.1115/1.4030173}, pages = {071002-1 -- 071002-7}, year = {2015}, language = {en} } @article{DuongNguyenTranetal.2015, author = {Duong, Minh Tuan and Nguyen, Nhu Huynh and Tran, Thanh Ngoc and Tolba, R. H. and Staat, Manfred}, title = {Influence of refrigerated storage on tensile mechanical properties of porcine liver and spleen}, series = {International biomechanics}, volume = {Vol. 2}, journal = {International biomechanics}, number = {Iss. 1}, publisher = {Taylor \& Francis}, address = {London}, issn = {2333-5432}, doi = {10.1080/23335432.2015.1049295}, pages = {79 -- 88}, year = {2015}, language = {en} } @article{DuongNguyenStaat2015, author = {Duong, Minh Tuan and Nguyen, Nhu Huynh and Staat, Manfred}, title = {Physical response of hyperelastic models for composite materials and soft tissues}, series = {Asia pacific journal on computational engineering}, volume = {2}, journal = {Asia pacific journal on computational engineering}, number = {3 (December 2015)}, issn = {2196-1166}, doi = {10.1186/s40540-015-0015-x}, pages = {1 -- 18}, year = {2015}, 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{KowalskiLinderZierkeetal.2016, author = {Kowalski, Julia and Linder, Peter and Zierke, S. and Wulfen, B. van and Clemens, J. and Konstantinidis, K. and Ameres, G. and Hoffmann, R. and Mikucki, J. and Tulaczyk, S. and Funke, O. and Blandfort, D. and Espe, Clemens and Feldmann, Marco and Francke, Gero and Hiecker, S. and Plescher, Engelbert and Sch{\"o}ngarth, Sarah and Dachwald, Bernd and Digel, Ilya and Artmann, Gerhard and Eliseev, D. and Heinen, D. and Scholz, F. and Wiebusch, C. and Macht, S. and Bestmann, U. and Reineking, T. and Zetzsche, C. and Schill, K. and F{\"o}rstner, R. and Niedermeier, H. and Szumski, A. and Eissfeller, B. and Naumann, U. and Helbing, K.}, title = {Navigation technology for exploration of glacier ice with maneuverable melting probes}, series = {Cold Regions Science and Technology}, journal = {Cold Regions Science and Technology}, number = {123}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0165-232X}, doi = {10.1016/j.coldregions.2015.11.006}, pages = {53 -- 70}, year = {2016}, abstract = {The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.}, language = {en} } @article{GrundmannDachwaldGrimmetal.2015, author = {Grundmann, Jan Thimo and Dachwald, Bernd and Grimm, Christian D. and Kahle, Ralph and Koch, Aaron Dexter and Krause, Christian and Lange, Caroline and Quantius, Dominik and Ulamec, Stephan}, title = {Spacecraft for Hypervelocity Impact Research - An Overview of Capabilities, Constraints and the Challenges of Getting There}, series = {Procedia Engineering}, volume = {Vol. 103}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.04.021}, pages = {151 -- 158}, year = {2015}, language = {en} } @article{GossmannFrotscherLinderetal.2016, author = {Goßmann, Matthias and Frotscher, Ralf and Linder, Peter and Bayer, Robin and Epple, U. and Staat, Manfred and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard}, title = {Mechano-pharmacological characterization of cardiomyocytes derived from human induced pluripotent stem cells}, series = {Cellular physiology and biochemistry}, volume = {38}, journal = {Cellular physiology and biochemistry}, number = {3}, publisher = {Karger}, address = {Basel}, issn = {1421-9778 (Online)}, doi = {10.1159/000443124}, pages = {1182 -- 1198}, year = {2016}, abstract = {Background/Aims: Common systems for the quantification of cellular contraction rely on animal-based models, complex experimental setups or indirect approaches. The herein presented CellDrum technology for testing mechanical tension of cellular monolayers and thin tissue constructs has the potential to scale-up mechanical testing towards medium-throughput analyses. Using hiPS-Cardiac Myocytes (hiPS-CMs) it represents a new perspective of drug testing and brings us closer to personalized drug medication. Methods: In the present study, monolayers of self-beating hiPS-CMs were grown on ultra-thin circular silicone membranes and deflect under the weight of the culture medium. Rhythmic contractions of the hiPS-CMs induced variations of the membrane deflection. The recorded contraction-relaxation-cycles were analyzed with respect to their amplitudes, durations, time integrals and frequencies. Besides unstimulated force and tensile stress, we investigated the effects of agonists and antagonists acting on Ca²⁺ channels (S-Bay K8644/verapamil) and Na⁺ channels (veratridine/lidocaine). Results: The measured data and simulations for pharmacologically unstimulated contraction resembled findings in native human heart tissue, while the pharmacological dose-response curves were highly accurate and consistent with reference data. Conclusion: We conclude that the combination of the CellDrum with hiPS-CMs offers a fast, facile and precise system for pharmacological, toxicological studies and offers new preclinical basic research potential.}, language = {en} } @article{FrotscherMuanghongDursunetal.2016, author = {Frotscher, Ralf and Muanghong, Danita and Dursun, G{\"o}zde and Goßmann, Matthias and Temiz Artmann, Ayseg{\"u}l and Staat, Manfred}, title = {Sample-specific adaption of an improved electro-mechanical model of in vitro cardiac tissue}, series = {Journal of Biomechanics}, volume = {49}, journal = {Journal of Biomechanics}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290 (Print)}, doi = {10.1016/j.jbiomech.2016.01.039}, pages = {2428 -- 2435}, year = {2016}, abstract = {We present an electromechanically coupled computational model for the investigation of a thin cardiac tissue construct consisting of human-induced pluripotent stem cell-derived atrial, ventricular and sinoatrial cardiomyocytes. The mechanical and electrophysiological parts of the finite element model, as well as their coupling are explained in detail. The model is implemented in the open source finite element code Code_Aster and is employed for the simulation of a thin circular membrane deflected by a monolayer of autonomously beating, circular, thin cardiac tissue. Two cardio-active drugs, S-Bay K8644 and veratridine, are applied in experiments and simulations and are investigated with respect to their chronotropic effects on the tissue. These results demonstrate the potential of coupled micro- and macroscopic electromechanical models of cardiac tissue to be adapted to experimental results at the cellular level. Further model improvements are discussed taking into account experimentally measurable quantities that can easily be extracted from the obtained experimental results. The goal is to estimate the potential to adapt the presented model to sample specific cell cultures.}, 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} } @article{HacklMuellerStaatetal.2016, author = {Hackl, Michael and M{\"u}ller, Lars-Peter and Staat, Manfred and Kahmann, Stephanie Lucina and Wegmann, Kilian}, title = {Proximal phalangeal neck fractures of the hand — a biomechanical comparison of three fixation techniques}, 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/s00167-016-4080-7}, pages = {148 -- 149}, year = {2016}, abstract = {Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis.}, language = {en} } @article{HacklKahmannWegmannetal.2016, author = {Hackl, Michael and Kahmann, Stephanie Lucina and Wegmann, Kilian and Ries, Christian and Staat, Manfred and M{\"u}ller, Lars-Peter}, title = {Shortening osteotomy of the proximal radius — a treatment option for isolated osteoarthritis of the lateral column of the elbow joint?}, 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/s00167-016-4080-7}, pages = {128 -- 129}, year = {2016}, abstract = {Treatment of posttraumatic osteoarthritis of the radial column of the elbow joint remains a challenging yet common issue. While partial joint replacement leads to high revision rates, radial head excision has shown to severely increase joint instability. Shortening osteotomy of the radius could be an option to decrease the contact pressure of the radiohumeral joint and thereby pain levels without causing valgus instability. Hence, the aim of this biomechanical study was to evaluate the effects of radial shortening on axial load distribution and valgus stability of the elbow joint.}, language = {en} } @article{HacklLeschingerStaatetal.2016, author = {Hackl, Michael and Leschinger, T. and Staat, Manfred and M{\"u}ller, Lars-Peter and Wegmann, Kilian}, title = {Reconstruction of the interosseous membrane in the Essex Lopresti lesion — a biomechanical evaluation}, 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/s00167-016-4080-7}, pages = {130 -- 131}, year = {2016}, abstract = {Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique.}, 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{PookhalilAmoabedinyTabeshetal.2016, author = {Pookhalil, Ali and Amoabediny, Ghassem and Tabesh, Hadi and Behbahani, Mehdi and Mottaghy, Khosrow}, title = {A new approach for semiempirical modeling of mechanical blood trauma}, series = {The international journal of artificial organs}, volume = {39}, journal = {The international journal of artificial organs}, number = {4}, publisher = {Sage}, address = {London}, issn = {1724-6040}, doi = {10.5301/ijao.5000474}, pages = {171 -- 177}, year = {2016}, abstract = {Purpose Two semi-empirical models were recently published, both making use of existing literature data, but each taking into account different physical phenomena that trigger hemolysis. In the first model, hemoglobin (Hb) release is described as a permeation procedure across the membrane, assuming a shear stress-dependent process (sublethal model). The second model only accounts for hemoglobin release that is caused by cell membrane breakdown, which occurs when red blood cells (RBC) undergo mechanically induced shearing for a period longer than the threshold time (nonuniform threshold model). In this paper, we introduce a model that considers the hemolysis generated by both these possible phenomena. Methods Since hemolysis can possibly be caused by permeation of hemoglobin through the RBC functional membrane as well as by release of hemoglobin from RBC membrane breakdown, our proposed model combines both these models. An experimental setup consisting of a Couette device was utilized for validation of our proposed model. Results A comparison is presented between the damage index (DI) predicted by the proposed model vs. the sublethal model vs. the nonthreshold model and experimental datasets. This comparison covers a wide range of shear stress for both human and porcine blood. An appropriate agreement between the measured DI and the DI predicted by the present model was obtained. Conclusions The semiempirical hemolysis model introduced in this paper aims for significantly enhanced conformity with experimental data. Two phenomenological outcomes become possible with the proposed approach: an estimation of the average time after which cell membrane breakdown occurs under the applied conditions, and a prediction of the ratio between the phenomena involved in hemolysis.}, language = {en} } @article{LeversStaatLaack2016, author = {Levers, A. and Staat, Manfred and Laack, Walter van}, title = {Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis}, series = {Orthopedic Practice}, volume = {47}, journal = {Orthopedic Practice}, number = {11}, pages = {521 -- 528}, year = {2016}, language = {en} } @article{NiedermeyerZhouDursunetal.2016, author = {Niedermeyer, Angela and Zhou, Bei and Dursun, G{\"o}zde and Temiz Artmann, Ayseg{\"u}l and Markert, Bernd}, title = {An examination of tissue engineered scaffolds in a bioreactor}, series = {Proceedings in Applied Mathematics and Mechanics PAMM}, volume = {16}, journal = {Proceedings in Applied Mathematics and Mechanics PAMM}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1617-7061}, doi = {10.1002/pamm.201610038}, pages = {99 -- 100}, year = {2016}, abstract = {Replacement tissues, designed to fill in articular cartilage defects, should exhibit the same properties as the native material. The aim of this study is to foster the understanding of, firstly, the mechanical behavior of the material itself and, secondly, the influence of cultivation parameters on cell seeded implants as well as on cell migration into acellular implants. In this study, acellular cartilage replacement material is theoretically, numerically and experimentally investigated regarding its viscoelastic properties, where a phenomenological model for practical applications is developed. Furthermore, remodeling and cell migration are investigated.}, language = {en} } @article{KotliarLanzl2016, author = {Kotliar, Konstantin and Lanzl, I. M.}, title = {Mit Statistik gemeistert: perfekte Augentropfen und idealer Screeningtest : M{\"o}glichkeiten und Grenzen statistischer Methoden beim Glaukom}, series = {Der Ophthalmologe: Zeitschrift Der Deutschen Ophthalmologischen Gesellschaft}, journal = {Der Ophthalmologe: Zeitschrift Der Deutschen Ophthalmologischen Gesellschaft}, number = {113}, publisher = {Springer}, address = {Berlin}, issn = {0941-293X}, doi = {10.1007/s00347-016-0312-y}, pages = {838 -- 843}, year = {2016}, abstract = {Hintergrund Die Anwendung und das Verst{\"a}ndnis von Statistik sind sehr wichtig f{\"u}r die biomedizinische Forschung und f{\"u}r die klinische Praxis. Dies gilt insbesondere auch zur Absch{\"a}tzung der M{\"o}glichkeiten unterschiedlichster Diagnostik- und Therapieoptionen beim Glaukom. Die scheinbare Komplexit{\"a}t der Statistik, die zum Teil dem „gesunden Menschenverstand" zu widersprechen scheint, zusammen mit der nur vorsichtigen Akzeptanz der Statistik bei vielen Medizinern k{\"o}nnen zu bewussten und unbewussten Manipulationen bei der Datendarstellung und -interpretation f{\"u}hren. Ziel der Arbeit Ziel ist die verst{\"a}ndliche Darstellung einiger typischer Fehler in der medizinisch-statistischen Datenbehandlung. Material und Methoden Anhand hypothetischer Beispiele aus der Glaukomdiagnostik erfolgen die Darstellung der Wirkung eines hypotensiven Medikamentes sowie die Beurteilung der Ergebnisse eines diagnostischen Tests. Es werden die typischsten statistischen Einsatzbereiche und Irrtumsquellen ausf{\"u}hrlich und verst{\"a}ndlich analysiert Ergebnisse Mechanismen von Datenmanipulation und falscher Dateninterpretation werden aufgekl{\"a}rt. Typische Irrtumsquellen bei der statistischen Auswertung und Datendarstellung werden dabei erl{\"a}utert. Schlussfolgerungen Die erl{\"a}uterten praktischen Beispiele zeigen die Notwendigkeit, die Grundlagen der Statistik zu verstehen und korrekt anwenden zu k{\"o}nnen. Fehlendes Grundlagenwissen und Halbwissen der medizinischen Statistik k{\"o}nnen zu folgenschweren Missverst{\"a}ndnissen und falschen Entscheidungen in der medizinischen Forschung, aber auch in der klinischen Praxis f{\"u}hren.}, language = {de} } @article{HacklAndermahrStaatetal.2017, author = {Hackl, M. and Andermahr, J. and Staat, Manfred and Bremer, I. and Borggrefe, J. and Prescher, A. and M{\"u}ller, L. P. and Wegmann, K.}, title = {Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation}, series = {The Journal of Hand Surgery (European Volume)}, volume = {42}, journal = {The Journal of Hand Surgery (European Volume)}, number = {4}, publisher = {Sage}, address = {London}, issn = {2043-6289 (Online)}, doi = {10.1177/1753193416665943}, pages = {370 -- 376}, year = {2017}, language = {en} } @article{Staat2012, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, volume = {19}, journal = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, pages = {45 -- 47}, year = {2012}, 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} } @article{YangKriechbaumerAlbrachtetal.2015, author = {Yang, Peng-Fei and Kriechbaumer, Andreas and Albracht, Kirsten and Sanno, Maximilian and Ganse, Bergita and Koy, Timmo and Shang, Peng and Br{\"u}ggemann, Gert-Peter and M{\"u}ller, Lars Peter and Rittweger, J{\"o}rn}, title = {On the relationship between tibia torsional deformation and regional muscle contractions in habitual human exercises in vivo}, series = {Journal of Biomechanics}, volume = {48}, journal = {Journal of Biomechanics}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2014.12.031}, pages = {456 -- 464}, year = {2015}, language = {en} } @article{SeynnesBojsenMollerAlbrachtetal.2015, author = {Seynnes, O. R. and Bojsen-Moller, J. and Albracht, Kirsten and Arndt, A. and Cronin, N. J. and Finni, T. and Magnusson, S. P.}, title = {Ultrasound-based testing of tendon mechanical properties: a critical evaluation}, series = {Journal of Applied Physiology}, volume = {118}, journal = {Journal of Applied Physiology}, number = {2}, issn = {8750-7587}, doi = {10.1152/japplphysiol.00849.2014}, pages = {133 -- 141}, year = {2015}, 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{KaramanidisAlbrachtBraunsteinetal.2011, author = {Karamanidis, Kiros and Albracht, Kirsten and Braunstein, Bjoern and Catala, Maria Moreno and Goldmann, Jan-Peter and Br{\"u}ggemann, Gert-Peter}, title = {Lower leg musculoskeletal geometry and sprint performance}, series = {Gait and Posture}, volume = {34}, journal = {Gait and Posture}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2011.03.009}, pages = {138 -- 141}, year = {2011}, abstract = {The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components.}, 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{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{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{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{LanzlKotliar2017, author = {Lanzl, I. and Kotliar, Konstantin}, title = {K{\"o}nnen Anti-VEGF-Injektionen Glaukom oder okul{\"a}re Hypertension verursachen?}, series = {Klinische Monatsbl{\"a}tter f{\"u}r Augenheilkunde}, volume = {234}, journal = {Klinische Monatsbl{\"a}tter f{\"u}r Augenheilkunde}, number = {2}, publisher = {Thieme}, address = {Stuttgart}, issn = {0023-2165}, doi = {10.1055/s-0043-101819}, pages = {191 -- 193}, year = {2017}, language = {de} }