TY - JOUR A1 - Fuest, Matthias A1 - Kotliar, Konstantin A1 - Walter, Peter A1 - Plange, Niklas T1 - Monitoring intraocular pressure changes after intravitreal Ranibizumab injection using rebound tonometry JF - Ophthalmic and physiological optics Y1 - 2014 U6 - http://dx.doi.org/10.1111/opo.12134 SN - 1475-1313 (E-Journal); 0275-5408 (Print) N1 - Special Issue: The Ageing Visual System VL - 34 IS - 4 SP - 438 EP - 444 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Turaliyeva, M. A1 - Yeshibaev, A. A1 - Digel, Ilya A1 - Elibayeva, G. A1 - Sydykova, A. A1 - Uspabayeva, A. A1 - Dosybayeva, G. A1 - Zhylysbayeva, A. A1 - Lakhanova, K. T1 - Molecular-genetic identification of emerged novel invasive pathogens of Asiatic Elm Ulmus pumila L JF - Life science journal N2 - The dwarf elm Ulmus pumila L. (Ulmaceae) is one of indigenous species of flora in Kazakhstan and forms a basis of dendroflora in virtually all settlements of the region. In the past decade, multiple outbreaks of previously unknown diseases of the small-leaved elm have been registered. In our study, by the molecular-genetic analysis it was found that the pathogens responsible for the outbreaks are microfungi belonging to the genus Fusarium – F. solani and F. oxysporum. The nucleotide sequences (ITS regions) isolated from the diseased trees showed very high similarity with the GenBank control numbers EU625403.1 and FJ478128.1 (100.0 and 99.0 % respectively). Oncoming research will focus on the search of natural microbial antagonists of the discovered phytopathogens. Y1 - 2014 U6 - http://dx.doi.org/10.7537/marslsj1105s14.33 SN - 1097-8135 VL - 11 IS - Spec. iss. 5s SP - 171 EP - 175 PB - Marsland Press CY - New York ER - TY - JOUR A1 - Stadler, Alexander Maximilian A1 - Garvey, Christopher J. A1 - Embs, Jan Peter A1 - Koza, Michael Marek A1 - Unruh, Tobias A1 - Artmann, Gerhard A1 - Zaccai, Guiseppe T1 - Picosecond dynamics in haemoglobin from different species: A quasielastic neutron scattering study JF - Biochimica et biophysica acta (BBA): General Subjects Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.bbagen.2014.06.007 SN - 1872-8006 (E-Journal); 0304-4165 (Print) VL - 1840 IS - 10 SP - 2989 EP - 2999 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ciobanu, Octavian A1 - Staat, Manfred A1 - Rahimi, Alireza T1 - The use of open source software in biomechanical finite element analysis JF - Buletinul Institutului Politehnic din Iaşi / Universitatea Tehnică Gh. Asachi, Iaşi Secţia 5, Construcţii de maşini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta Y1 - 2008 SN - 1011-2855 VL - 54 IS - 7/8 SP - 213 EP - 220 ER - TY - JOUR A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Stresses produced by different textile mesh implants in a tissue equivalent JF - BioNanoMaterials N2 - 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. Y1 - 2014 U6 - http://dx.doi.org/10.1515/bnm-2014-0003 SN - 2191-4672 (E-Journal); 2193-066X (E-Journal); 0011-8656 (Print); 1616-0177 (Print); 2193-0651 (Print) VL - 15 IS - 1-2 SP - 25 EP - 30 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Konstantinidis, Konstantinos A1 - Flores Martinez, Claudio A1 - Dachwald, Bernd A1 - Ohndorf, Andreas A1 - Dykta, Paul A1 - Bowitz, Pascal A1 - Rudolph, Martin A1 - Digel, Ilya A1 - Kowalski, Julia A1 - Voigt, Konstantin A1 - Förstner, Roger T1 - A lander mission to probe subglacial water on Saturn's moon enceladus for life JF - Acta astronautica Y1 - 2015 SN - 1879-2030 (E-Journal); 0094-5765 (Print) VL - Vol. 106 SP - 63 EP - 89 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dachwald, Bernd A1 - Mikucki, Jill A1 - Tulaczyk, Slawek A1 - Digel, Ilya A1 - Espe, Clemens A1 - Feldmann, Marco A1 - Francke, Gero A1 - Kowalski, Julia A1 - Xu, Changsheng T1 - IceMole : A maneuverable probe for clean in situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems JF - Annals of Glaciology N2 - 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. KW - Antarctic Glaciology KW - Extraterrestrial Glaciology KW - Glaciological instruments and methods KW - Subclacial exploration KW - Subglacial lakes Y1 - 2014 U6 - http://dx.doi.org/10.3189/2014AoG65A004 SN - 1727-5644 VL - 55 IS - 65 SP - 14 EP - 22 PB - Cambridge University Press CY - Cambridge ER - TY - JOUR A1 - Baroud, G. A1 - Wu, J.Z. A1 - Bohner, M A1 - Sponagel, Stefan A1 - Steffen, T. T1 - How to determine the permeability for cement infiltration into osteoporotic cancellous bone JF - Medical Engineering & Physics. 25 (2003), H. 4 N2 - 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. KW - Osteoporose KW - Permeabilität KW - Viskose Strömung KW - Viskosität KW - Vertebroplastie KW - Cement infiltration KW - Vertebroplasty KW - Osteoporosis KW - Permeability KW - Experiment KW - Analysis KW - Viscous flow Y1 - 2003 SN - 1350-4533 SP - 283 EP - 288 ER - TY - JOUR A1 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels N2 - 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. KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohr KW - Rohrbruch KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohrbruch KW - Fehlerstellen KW - pipes KW - vessels KW - load limit KW - burst tests KW - burst pressure KW - flaw Y1 - 2004 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels N2 - 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. KW - Finite-Elemente-Methode KW - Grenzwertberechnung KW - Axialbelastung KW - FEM KW - Grenzwertberechnung KW - Axialbelastung KW - Traglastanalyse KW - Limit analysis KW - Global and local collapse KW - Axially cracked pipe KW - Pressure loaded crack-face Y1 - 2005 ER - TY - JOUR A1 - Staat, Manfred T1 - Direct finite element route for design-by-analysis of pressure components N2 - 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. KW - Einspielen KW - Plastizität KW - Deformation KW - Analytischer Zulaessigkeitsnachweis KW - Einspiel-Analyse KW - fortschreitende plastische Deformation KW - alternierend Verformbarkeit KW - Einspiel-Kriterium KW - Design-by-analysis KW - Shakedown analysis KW - Progressive plastic deformation KW - Alternating plasticity KW - Shakedown criterion Y1 - 2005 ER - TY - JOUR A1 - Staat, Manfred T1 - Shakedown and ratchetting under tension-torsion loadings: analysis and experiments N2 - 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. KW - Einspielen KW - Einspielen KW - Ratchetting KW - Zug-Druck Belastung KW - shakedown KW - ratchetting KW - tension–torsion loading Y1 - 2003 ER - TY - JOUR A1 - Vu, Duc-Khoi A1 - Staat, Manfred T1 - An algorithm for shakedown analysis of structure with temperature dependent yield stress N2 - 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. KW - Einspielen KW - Temperaturabhängigkeit KW - Fließgrenze KW - Shakedown KW - shakedown analysis KW - yield stress Y1 - 2004 ER - TY - JOUR A1 - Kühn, Raoul-Roman A1 - Haugner, Werner A1 - Staat, Manfred A1 - Sponagel, Stefan T1 - A Two Phase Mixture Model based on Bone Observation N2 - 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. KW - Knochen KW - Knochenbildung KW - Knochenchirugie KW - Strukturanalyse KW - Schwammknochen KW - Knochendichte KW - Wolffsches Gesetz KW - bone structure KW - bone density KW - Wolff's Law KW - cancellous bone Y1 - 2004 ER - TY - JOUR A1 - Seifarth, Volker A1 - Goßmann, Matthias A1 - Grosse, J. O. A1 - Becker, C. A1 - Heschel, I. A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Development of a Bioreactor to Culture Tissue Engineered Ureters Based on the Application of Tubular OPTIMAIX 3D Scaffolds JF - Urologia Internationalis Y1 - 2015 U6 - http://dx.doi.org/10.1159/000368419 SN - 0042-1138 VL - 2015 IS - 95 SP - 106 EP - 113 PB - Karger CY - Basel ER - TY - JOUR A1 - Martin-Gonzalez, Anabel A1 - Kotliar, Konstantin A1 - Rios-Martinez, Jorge A1 - Lanzl, Ines A1 - Navab, Nassir T1 - Mediated-reality magnification for macular degeneration rehabilitation JF - Journal of Modern Optics Y1 - 2014 U6 - http://dx.doi.org/10.1080/09500340.2014.936110 SN - 1362-3044 VL - 61 IS - 17 SP - 1400 EP - 1408 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Kotliar, Konstantin A1 - Kharoubi, A. A1 - Schmidt-Trucksäß, A. A1 - Halle, M. A1 - Lanzl, I. T1 - Does internal longitudinal microstructure of retinal veins change with age in medically healthy persons? JF - Acta Ophthalmologica Y1 - 2009 SN - 1600-0420 (E-Journal); 1755-3768 (E-Journal); 0001-639X (Print); 1395-3907 (Print); 1755-375X (Print) VL - Vol. 87 IS - Suppl. S244 SP - 0 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Frotscher, Ralf A1 - Koch, Jan-Peter A1 - Staat, Manfred T1 - Computational investigation of drug action on human-induced stem cell derived cardiomyocytes JF - Journal of biomechanical engineering Y1 - 2015 U6 - http://dx.doi.org/10.1115/1.4030173 SN - 1528-8951 (E-Journal); 0148-0731 (Print) VL - Vol. 137 IS - iss. 7 SP - 071002-1 EP - 071002-7 PB - ASME CY - New York ER - TY - JOUR A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Huynh A1 - Tran, Thanh Ngoc A1 - Tolba, R. H. A1 - Staat, Manfred T1 - Influence of refrigerated storage on tensile mechanical properties of porcine liver and spleen JF - International biomechanics Y1 - 2015 U6 - http://dx.doi.org/10.1080/23335432.2015.1049295 SN - 2333-5432 VL - Vol. 2 IS - Iss. 1 SP - 79 EP - 88 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Huynh A1 - Staat, Manfred T1 - Physical response of hyperelastic models for composite materials and soft tissues JF - Asia pacific journal on computational engineering Y1 - 2015 U6 - http://dx.doi.org/10.1186/s40540-015-0015-x SN - 2196-1166 VL - 2 IS - 3 (December 2015) SP - 1 EP - 18 ER - TY - JOUR A1 - Cehreli, Ruksan A1 - Akpinar, Hale A1 - Temiz Artmann, Aysegül A1 - Sagol, Ozgul T1 - Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis JF - Gastroenterology Research Y1 - 2015 U6 - http://dx.doi.org/10.14740/gr683w SN - 1918-2813 VL - 8 IS - 5 SP - 265 EP - 273 ER - TY - JOUR A1 - Kowalski, Julia A1 - Linder, Peter A1 - Zierke, S. A1 - Wulfen, B. van A1 - Clemens, J. A1 - Konstantinidis, K. A1 - Ameres, G. A1 - Hoffmann, R. A1 - Mikucki, J. A1 - Tulaczyk, S. A1 - Funke, O. A1 - Blandfort, D. A1 - Espe, Clemens A1 - Feldmann, Marco A1 - Francke, Gero A1 - Hiecker, S. A1 - Plescher, Engelbert A1 - Schöngarth, Sarah A1 - Dachwald, Bernd A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Eliseev, D. A1 - Heinen, D. A1 - Scholz, F. A1 - Wiebusch, C. A1 - Macht, S. A1 - Bestmann, U. A1 - Reineking, T. A1 - Zetzsche, C. A1 - Schill, K. A1 - Förstner, R. A1 - Niedermeier, H. A1 - Szumski, A. A1 - Eissfeller, B. A1 - Naumann, U. A1 - Helbing, K. T1 - Navigation technology for exploration of glacier ice with maneuverable melting probes JF - Cold Regions Science and Technology N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.coldregions.2015.11.006 SN - 0165-232X IS - 123 SP - 53 EP - 70 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Grundmann, Jan Thimo A1 - Dachwald, Bernd A1 - Grimm, Christian D. A1 - Kahle, Ralph A1 - Koch, Aaron Dexter A1 - Krause, Christian A1 - Lange, Caroline A1 - Quantius, Dominik A1 - Ulamec, Stephan T1 - Spacecraft for Hypervelocity Impact Research – An Overview of Capabilities, Constraints and the Challenges of Getting There JF - Procedia Engineering Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.proeng.2015.04.021 SN - 1877-7058 N1 - Proceedings of the 2015 Hypervelocity Impact Symposium (HVIS 2015) VL - Vol. 103 SP - 151 EP - 158 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Goßmann, Matthias A1 - Frotscher, Ralf A1 - Linder, Peter A1 - Bayer, Robin A1 - Epple, U. A1 - Staat, Manfred A1 - Temiz Artmann, Aysegül A1 - Artmann, Gerhard T1 - Mechano-pharmacological characterization of cardiomyocytes derived from human induced pluripotent stem cells JF - Cellular physiology and biochemistry N2 - 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. KW - Inotropic compounds KW - Pharmacology KW - Ion channels KW - CellDrum KW - Heart tissue culture KW - Induced pluripotent stem cells KW - Cardiac myocytes Y1 - 2016 U6 - http://dx.doi.org/10.1159/000443124 SN - 1421-9778 (Online) SN - 1015-8987 (Print) VL - 38 IS - 3 SP - 1182 EP - 1198 PB - Karger CY - Basel ER - TY - JOUR A1 - Frotscher, Ralf A1 - Muanghong, Danita A1 - Dursun, Gözde A1 - Goßmann, Matthias A1 - Temiz Artmann, Aysegül A1 - Staat, Manfred T1 - Sample-specific adaption of an improved electro-mechanical model of in vitro cardiac tissue JF - Journal of Biomechanics N2 - 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. KW - hiPS cardiomyocytes KW - Homogenization KW - Hodgkin–Huxley models KW - Frequency adaption KW - Electromechanical modeling KW - Drug simulation KW - Computational biomechanics KW - Cardiac tissue Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.jbiomech.2016.01.039 SN - 0021-9290 (Print) SN - 1873-2380 (Online) VL - 49 IS - 12 SP - 2428 EP - 2435 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hackl, Michael A1 - Müller, Lars-Peter A1 - Staat, Manfred A1 - Kahmann, Stephanie Lucina A1 - Wegmann, Kilian T1 - Proximal phalangeal neck fractures of the hand — a biomechanical comparison of three fixation techniques JF - Knee surgery, sports traumatology, arthroscopy N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 148 EP - 149 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hackl, Michael A1 - Kahmann, Stephanie Lucina A1 - Wegmann, Kilian A1 - Ries, Christian A1 - Staat, Manfred A1 - Müller, Lars-Peter T1 - Shortening osteotomy of the proximal radius — a treatment option for isolated osteoarthritis of the lateral column of the elbow joint? JF - Knee surgery, sports traumatology, arthroscopy N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 128 EP - 129 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hackl, Michael A1 - Leschinger, T. A1 - Staat, Manfred A1 - Müller, Lars-Peter A1 - Wegmann, Kilian T1 - Reconstruction of the interosseous membrane in the Essex Lopresti lesion — a biomechanical evaluation JF - Knee surgery, sports traumatology, arthroscopy N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 130 EP - 131 PB - Springer CY - Berlin ER - TY - JOUR A1 - Wegmann, Kilian A1 - Hackl, Michael A1 - Staat, Manfred A1 - Mayer, Katharina A1 - Müller, Lars-Peter T1 - Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results JF - Knee surgery, sports traumatology, arthroscopy N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4079-0 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 58 EP - 59 PB - Springer CY - Berlin ER - TY - JOUR A1 - Pookhalil, Ali A1 - Amoabediny, Ghassem A1 - Tabesh, Hadi A1 - Behbahani, Mehdi A1 - Mottaghy, Khosrow T1 - A new approach for semiempirical modeling of mechanical blood trauma JF - The international journal of artificial organs N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.5301/ijao.5000474 SN - 1724-6040 VL - 39 IS - 4 SP - 171 EP - 177 PB - Sage CY - London ER - TY - JOUR A1 - Levers, A. A1 - Staat, Manfred A1 - Laack, Walter van T1 - Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis JF - Orthopedic Practice Y1 - 2016 VL - 47 IS - 11 SP - 521 EP - 528 ER - TY - JOUR A1 - Niedermeyer, Angela A1 - Zhou, Bei A1 - Dursun, Gözde A1 - Temiz Artmann, Aysegül A1 - Markert, Bernd T1 - An examination of tissue engineered scaffolds in a bioreactor JF - Proceedings in Applied Mathematics and Mechanics PAMM N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1002/pamm.201610038 SN - 1617-7061 N1 - Joint Annual Meeting of DMV and GAMM 2016, 87th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung (DMV), Braunschweig, DE, Mar 7-11, 2016 VL - 16 IS - 1 SP - 99 EP - 100 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Hackl, M. A1 - Andermahr, J. A1 - Staat, Manfred A1 - Bremer, I. A1 - Borggrefe, J. A1 - Prescher, A. A1 - Müller, L. P. A1 - Wegmann, K. T1 - Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation JF - The Journal of Hand Surgery (European Volume) Y1 - 2017 U6 - http://dx.doi.org/10.1177/1753193416665943 SN - 2043-6289 (Online) SN - 1753-1934 (Print) VL - 42 IS - 4 SP - 370 EP - 376 PB - Sage CY - London ER - TY - JOUR A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty JF - Tap chi Khoa hoc & ung dung - Dai hoc Ton Duc Thang Y1 - 2012 N1 - = Journal of Applied Sciences - Ton Duc Thang University VL - 19 SP - 45 EP - 47 ER - TY - JOUR A1 - Belavy, Daniel L. A1 - Albracht, Kirsten A1 - Bruggemann, Gert-Peter A1 - Vergroesen, Pieter-Paul A. A1 - Dieen, Jaap H. van T1 - Can exercise positively influence the intervertebral disc? JF - Sports Medicine N2 - 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. KW - Intradiscal Pressure KW - Annulus Fibrosus KW - Disc Degeneration KW - Nucleus Pulposus KW - Intervertebral Disc Y1 - 2016 U6 - http://dx.doi.org/10.1007/s40279-015-0444-2 SN - 1179-2035 VL - 46 IS - 4 SP - 473 EP - 485 PB - Springer CY - Berlin ER - TY - JOUR A1 - Yang, Peng-Fei A1 - Kriechbaumer, Andreas A1 - Albracht, Kirsten A1 - Sanno, Maximilian A1 - Ganse, Bergita A1 - Koy, Timmo A1 - Shang, Peng A1 - Brüggemann, Gert-Peter A1 - Müller, Lars Peter A1 - Rittweger, Jörn T1 - On the relationship between tibia torsional deformation and regional muscle contractions in habitual human exercises in vivo JF - Journal of Biomechanics Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.jbiomech.2014.12.031 SN - 0021-9290 VL - 48 IS - 3 SP - 456 EP - 464 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Seynnes, O. R. A1 - Bojsen-Moller, J. A1 - Albracht, Kirsten A1 - Arndt, A. A1 - Cronin, N. J. A1 - Finni, T. A1 - Magnusson, S. P. T1 - Ultrasound-based testing of tendon mechanical properties: a critical evaluation JF - Journal of Applied Physiology Y1 - 2015 U6 - http://dx.doi.org/10.1152/japplphysiol.00849.2014 SN - 8750-7587 VL - 118 IS - 2 SP - 133 EP - 141 ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios T1 - Exercise-induced changes in triceps surae tendon stiffness and muscle strength affect running economy in humans JF - European Journal of Applied Physiology Y1 - 2013 U6 - http://dx.doi.org/10.1007/s00421-012-2585-4 SN - 1439-6327 VL - 113 IS - 6 SP - 1605 EP - 1615 PB - Springer CY - Berlin ER - TY - JOUR A1 - Karamanidis, Kiros A1 - Albracht, Kirsten A1 - Braunstein, Bjoern A1 - Catala, Maria Moreno A1 - Goldmann, Jan-Peter A1 - Brüggemann, Gert-Peter T1 - Lower leg musculoskeletal geometry and sprint performance JF - Gait and Posture N2 - 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. Y1 - 2011 U6 - http://dx.doi.org/10.1016/j.gaitpost.2011.03.009 SN - 0966-6362 VL - 34 IS - 1 SP - 138 EP - 141 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Arampatzis, Adamantios A1 - Karamanidis, Kiros A1 - Mademli, Lida A1 - Albracht, Kirsten T1 - Plasticity of the human tendon to short and long-term mechanical loading JF - Exercise and Sport Sciences Reviews Y1 - 2009 U6 - http://dx.doi.org/10.1097/JES.0b013e31819c2e1d SN - 1538-3008 VL - 37 IS - 2 SP - 66 EP - 72 ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, A. A1 - Baltzopoulos, V. T1 - Assessment of muscle volume and physiological cross-sectional area of the human triceps surae muscle in vivo JF - Journal of Biomechanics Y1 - 2008 U6 - http://dx.doi.org/10.1016/j.jbiomech.2008.04.020 SN - 0021-9290 VL - 41 SP - 2211 EP - 2218 ER - TY - JOUR A1 - Arampatzis, Adamantios A1 - Karamanidis, Kiros A1 - Albracht, Kirsten T1 - Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude JF - Journal of Experimental Biology Y1 - 2007 U6 - http://dx.doi.org/10.1242/jeb.003814 SN - 0022-0949 VL - 210 IS - 15 SP - 2743 EP - 2753 ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios T1 - Influence of the mechanical properties of the muscle-tendon unit on force generation in runners with different running economy JF - Biological Cybernetics Y1 - 2006 U6 - http://dx.doi.org/10.1007/s00422-006-0070-z SN - 1432-0770 VL - 95 IS - 1 SP - 87 EP - 96 ER - TY - JOUR A1 - Hackl, Michael A1 - Wegmann, Kilian A1 - Kahmann, Stephanie Lucina A1 - Heinze, Nicolai A1 - Staat, Manfred A1 - Neiss, Wolfram F. A1 - Scaal, Martin A1 - Müller, Lars P. T1 - Radial shortening osteotomy reduces radiocapitellar contact pressures while preserving valgus stability of the elbow JF - Knee Surgery, Sports Traumatology, Arthroscopy Y1 - 2017 U6 - http://dx.doi.org/10.1007/s00167-017-4468-z SN - 1433-7347 VL - 25 IS - 7 SP - 2280 EP - 2288 PB - Springer CY - Berlin ER - TY - JOUR A1 - Zange, Jochen A1 - Schopen, Kathrin A1 - Albracht, Kirsten A1 - Gerlach, Darius A. A1 - Frings-Meuthen, Petra A1 - Maffiuletti, Nicola A. A1 - Bloch, Wilhelm A1 - Rittweger, Jörn T1 - Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial JF - Plos one Y1 - 2017 U6 - http://dx.doi.org/10.1371/journal.pone.0171562 VL - 12 IS - 2 ER - TY - JOUR A1 - Ciritsis, Alexander A1 - Horbach, Andreas A1 - Staat, Manfred A1 - Kuhl, Christiane K. A1 - Kraemer, Nils Andreas T1 - Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo JF - Journal of Biomedical Materials Research: Part B: Applied Biomaterials N2 - Purpose In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model. Material and Methods Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio). Results In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4% for TPU and of 1.2% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF. Conclusion The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827–833, 2018. Y1 - 2018 U6 - http://dx.doi.org/10.1002/jbm.b.33877 SN - 1552-4981 VL - 106 IS - 2 SP - 827 EP - 833 PB - Wiley CY - New York, NY ER - TY - JOUR A1 - Michael, Hackl A1 - Mayer, Katharina A1 - Weber, Mareike A1 - Staat, Manfred A1 - van Riet, Roger A1 - Burkhart, Klau Josef A1 - Müller, Lars Peter A1 - Wegmann, Kilian T1 - Plate osteosynthesis of proximal ulna fractures : a biomechanical micromotion analysis JF - The journal of hand surgery Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.jhsa.2017.05.014 SN - 0363-5023 VL - 42 IS - 10 SP - 834.e1 EP - 834.e7 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Horbach, Andreas A1 - Duong, Minh Tuan A1 - Staat, Manfred T1 - Modelling of compressible and orthotropic surgical mesh implants based on optical deformation measurement JF - Journal of the mechanical behavior of biomedical materials Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.jmbbm.2017.06.012 SN - 1751-6161 VL - 74 SP - 400 EP - 410 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tran, Linda A1 - Mottaghy, K. A1 - Arlt-Körfer, Sabine A1 - Waluga, Christian A1 - Behbahani, Mehdi T1 - An experimental study of shear-dependent human platelet adhesion and underlying protein-binding mechanisms in a cylindrical Couette system JF - Biomedizinische Technik Y1 - 2017 U6 - http://dx.doi.org/10.1515/bmt-2015-0034 SN - 0013-5585 VL - 62 IS - 4 SP - 383 EP - 392 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Albanna, Walid A1 - Lueke, Jan Niklas A1 - Sjapic, Volha A1 - Kotliar, Konstantin A1 - Hescheler, Jürgen A1 - Clusmann, Hans A1 - Sjapic, Sergej A1 - Alpdogan, Serdan A1 - Schneider, Toni A1 - Schubert, Gerrit Alexander A1 - Neumaier, Felix T1 - Electroretinographic Assessment of Inner Retinal Signaling in the Isolated and Superfused Murine Retina JF - Current Eye Research Y1 - 2017 U6 - http://dx.doi.org/10.1080/02713683.2017.1339807 SN - 1460-2202 IS - Article in press SP - 1 EP - 9 PB - Taylor & Francis CY - London ER -