@article{HeinkeKnickerAlbracht2021, author = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten}, title = {Test-retest reliability of the internal shoulder rotator muscles' stretch reflex in healthy men}, series = {Journal of Electromyography and Kinesiology}, volume = {62}, journal = {Journal of Electromyography and Kinesiology}, number = {Article 102611}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1050-6411}, doi = {10.1016/j.jelekin.2021.102611}, year = {2021}, abstract = {Until now the reproducibility of the short latency stretch reflex of the internal rotator muscles of the glenohumeral joint has not been identified. Twenty-three healthy male participants performed three sets of external shoulder rotation stretches with various pre-activation levels on two different dates of measurement to assess test-retest reliability. All stretches were applied with a dynamometer acceleration of 104°/s2 and a velocity of 150°/s. Electromyographical response was measured via surface EMG. Reflex latencies showed a pre-activation effect (ƞ2 = 0,355). ICC ranged from 0,735 to 0,909 indicating an overall "good" relative reliability. SRD 95\% lay between ±7,0 to ±12,3 ms.. The reflex gain showed overall poor test-retest reproducibility. The chosen methodological approach presented a suitable test protocol for shoulder muscles stretch reflex latency evaluation. A proof-of-concept study to validate the presented methodical approach in shoulder involvement including subjects with clinically relevant conditions is recommended.}, language = {en} } @article{HeinzelSchaeferMuelleretal.2010, author = {Heinzel, Alexander and Sch{\"a}fer, Ralf and M{\"u}ller, Hans-Wilhelm and Schieffer, Andre and Ingenhag, Ariane and Eickhoff, Simon B. and Northoff, Georg and Franz, Matthias and Hautzel, Hubertus}, title = {Increased Activation of the Supragenual Anterior Cingulate Cortex during Visual Emotional Processing in Male Subjects with High Degrees of Alexithymia: An Event-Related fMRI Study}, series = {Psychotherapy and Psychosomatics}, volume = {79}, journal = {Psychotherapy and Psychosomatics}, number = {6}, publisher = {Karger}, address = {Basel}, issn = {0033-3190}, doi = {10.1159/000320121}, pages = {363 -- 370}, year = {2010}, abstract = {Background: One of the most prominent neurobiological models of alexithymia assumes an altered function of the anterior cingulate cortex (ACC) as the crucial neural correlate of alexithymia. So far functional imaging studies have yielded inconclusive results. Therefore, we tested this hypothesis in healthy alexithymics and nonalexithymics in an event-related fMRI study. Methods: Thirty high- and 30 low-alexithymic right-handed male subjects (selected by the 20-item Toronto Alexithymia Scale, TAS-20) were investigated with event-related fMRI using a picture viewing paradigm. The stimuli consisted of happy, fearful and neutral facial expressions (Ekman-Friesen) as well as positive, negative and neutral pictures from the International Affective Picture System. Results: Contrasting the high-alexithymic with the low-alexithymic group we observed increased activation of the supragenual ACC for different emotional valences as well as for different emotional stimuli. Moreover, there was a positive correlation of the ACC with the individual TAS-20 scores but no correlations with the individual Beck Depression Inventory scores. Additionally, there was no difference in activity of the amygdala. Conclusions: We demonstrated that the supragenual ACC is constantly activated more strongly in alexithymic subjects and that this activation is related to the symptoms of alexithymia and not to associated symptoms such as depression. Therefore, our findings support the hypothesis of an altered function of the ACC in alexithymia.}, language = {en} } @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} } @article{HerssensCowburnAlbrachtetal.2022, author = {Herssens, Nolan and Cowburn, James and Albracht, Kirsten and Braunstein, Bjoern and Cazzola, Dario and Colyer, Steffi and Minetti, Alberto E. and Pavei, Gaspare and Rittweger, J{\"o}rn and Weber, Tobias and Green, David A.}, title = {Movement in low gravity environments (MoLo) programme - the MoLo-L.O.O.P. study protocol}, series = {PLOS ONE / Public Library of Science}, volume = {17}, journal = {PLOS ONE / Public Library of Science}, number = {11}, editor = {Cattaneo, Luigi}, publisher = {Plos}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0278051}, pages = {e0278051}, year = {2022}, abstract = {Exposure to prolonged periods in microgravity is associated with deconditioning of the musculoskeletal system due to chronic changes in mechanical stimulation. Given astronauts will operate on the Lunar surface for extended periods of time, it is critical to quantify both external (e.g., ground reaction forces) and internal (e.g., joint reaction forces) loads of relevant movements performed during Lunar missions. Such knowledge is key to predict musculoskeletal deconditioning and determine appropriate exercise countermeasures associated with extended exposure to hypogravity.}, language = {en} } @article{HorbachDuongStaat2017, author = {Horbach, Andreas and Duong, Minh Tuan and Staat, Manfred}, title = {Modelling of compressible and orthotropic surgical mesh implants based on optical deformation measurement}, series = {Journal of the mechanical behavior of biomedical materials}, volume = {74}, journal = {Journal of the mechanical behavior of biomedical materials}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1751-6161}, doi = {10.1016/j.jmbbm.2017.06.012}, pages = {400 -- 410}, year = {2017}, language = {en} } @article{HorbachStaat2018, author = {Horbach, Andreas and Staat, Manfred}, title = {Optical strain measurement for the modeling of surgical meshes and their porosity}, series = {Current Directions in Biomedical Engineering}, volume = {Band 4}, journal = {Current Directions in Biomedical Engineering}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {2364-5504}, doi = {10.1515/cdbme-2018-0045}, pages = {181 -- 184}, year = {2018}, abstract = {The porosity of surgical meshes makes them flexible for large elastic deformation and establishes the healing conditions of good tissue in growth. The biomechanic modeling of orthotropic and compressible materials requires new materials models and simulstaneoaus fit of deformation in the load direction as well as trannsversely to to load. This nonlinear modeling can be achieved by an optical deformation measurement. At the same time the full field deformation measurement allows the dermination of the change of porosity with deformation. Also the socalled effective porosity, which has been defined to asses the tisssue interatcion with the mesh implants, can be determined from the global deformation of the surgical meshes.}, language = {en} } @article{HorbachStaatPerezVianaetal.2020, author = {Horbach, Andreas and Staat, Manfred and Perez-Viana, Daniel and Simmen, Hans-Peter and Neuhaus, Valentin and Pape, Hans-Christoph and Prescher, Andreas and Ciritsis, Bernhard}, title = {Biomechanical in vitro examination of a standardized low-volume tubular femoroplasty}, series = {Clinical Biomechanics}, volume = {80}, journal = {Clinical Biomechanics}, number = {Art. 105104}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.clinbiomech.2020.105104}, year = {2020}, abstract = {Background Osteoporosis is associated with the risk of fractures near the hip. Age and comorbidities increase the perioperative risk. Due to the ageing population, fracture of the proximal femur also proves to be a socio-economic problem. Preventive surgical measures have hardly been used so far. Methods 10 pairs of human femora from fresh cadavers were divided into control and low-volume femoroplasty groups and subjected to a Hayes fall-loading fracture test. The results of the respective localization and classification of the fracture site, the Singh index determined by computed tomography (CT) examination and the parameters in terms of fracture force, work to fracture and stiffness were evaluated statistically and with the finite element method. In addition, a finite element parametric study with different position angles and variants of the tubular geometry of the femoroplasty was performed. Findings Compared to the control group, the work to fracture could be increased by 33.2\%. The fracture force increased by 19.9\%. The used technique and instrumentation proved to be standardized and reproducible with an average poly(methyl methacrylate) volume of 10.5 ml. The parametric study showed the best results for the selected angle and geometry. Interpretation The cadaver studies demonstrated the biomechanical efficacy of the low-volume tubular femoroplasty. The numerical calculations confirmed the optimal choice of positioning as well as the inner and outer diameter of the tube in this setting. The standardized minimally invasive technique with the instruments developed for it could be used in further comparative studies to confirm the measured biomechanical results.}, language = {en} } @article{HunkerGossmannRamanetal.2021, author = {Hunker, Jan L. and Gossmann, Matthias and Raman, Aravind Hariharan and Linder, Peter}, title = {Artificial neural networks in cardiac safety assessment: Classification of chemotherapeutic compound effects on hiPSC-derived cardiomyocyte contractility}, series = {Journal of Pharmacological and Toxicological Methods}, volume = {111}, journal = {Journal of Pharmacological and Toxicological Methods}, number = {Article number 107044}, publisher = {Elsevier}, address = {New York}, issn = {1056-8719}, doi = {10.1016/j.vascn.2021.107044}, year = {2021}, language = {en} } @article{JanThimoBauerBieleetal.2019, author = {Jan Thimo, Grundmann and Bauer, Waldemar and Biele, Jens and Boden, Ralf and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Hercik, David}, title = {Capabilities of Gossamer-1 derived small spacecraft solar sails carrying Mascot-derived nanolanders for in-situ surveying of NEAs}, series = {Acta Astronautica}, volume = {156}, journal = {Acta Astronautica}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0094-5765}, doi = {10.1016/j.actaastro.2018.03.019}, pages = {330 -- 362}, year = {2019}, language = {en} } @article{JansenBehbahaniLaumenetal.2010, author = {Jansen, S. V. and Behbahani, Mehdi and Laumen, M. and Kaufmann, T. and Hormes, M. and Behr, M. and Schmitz-Rode, T. and Steinseifer, U.}, title = {Investigation of Steady Flow Through a Realistic Model of the Thoracic Human Aorta Using 3D Stereo PIV and CFD-Simulation}, year = {2010}, language = {en} } @article{JansenBehbahaniLaumenetal.2010, author = {Jansen, Sebastian and Behbahani, Mehdi and Laumen, Marco and Kaufmann, Tim and Hormes, Marcus and Schmitz-Rode, Thomas and Behr, Marek and Steinseifer, Ulrich}, title = {3D Stereo-PIV Validation for CFD-Simulation of Steady Flow through the Human Aorta using Rapid-Prototyping techniques}, year = {2010}, language = {en} } @article{JayaramanMummidisettyLoeschetal.2019, author = {Jayaraman, Chandrasekaran and Mummidisetty, Chaitanya Krishna and Loesch, Alexandra and Kaur, Sandi and Hoppe-Ludwig, Shenan and Staat, Manfred and Jayaraman, Arun}, title = {Postural and metabolic benefits of using a forearm support walker in older adults with impairments}, series = {Archives of Physical Medicine and Rehabilitation}, volume = {Volume 100}, journal = {Archives of Physical Medicine and Rehabilitation}, number = {Issue 4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0003-9993}, doi = {10.1016/j.apmr.2018.10.001}, pages = {638 -- 647}, year = {2019}, language = {en} } @article{JiminezGermanBehbahaniMiettinenetal.2013, author = {Jiminez German, Salvador and Behbahani, Mehdi and Miettinen, Susanna and Grijpma, Dirk W. and Haimi, Suvi P.}, title = {Proliferation and differentiation of adipose stem cells towards smooth muscle cells on poly(trimethylene carbonate) membranes}, series = {Macromolecular symposia}, volume = {Vol. 334}, journal = {Macromolecular symposia}, number = {Iss. 1}, publisher = {Wiley}, address = {Weinheim}, issn = {0258-0322}, pages = {133 -- 142}, year = {2013}, language = {en} } @article{JungMuellerStaat2018, author = {Jung, Alexander and M{\"u}ller, Wolfram and Staat, Manfred}, title = {Wind and fairness in ski jumping: A computer modelling analysis}, series = {Journal of Biomechanics}, journal = {Journal of Biomechanics}, number = {75}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2018.05.001}, pages = {147 -- 153}, year = {2018}, abstract = {Wind is closely associated with the discussion of fairness in ski jumping. To counter-act its influence on the jump length, the International Ski Federation (FIS) has introduced a wind compensation approach. We applied three differently accurate computer models of the flight phase with wind (M1, M2, and M3) to study the jump length effects of various wind scenarios. The previously used model M1 is accurate for wind blowing in direction of the flight path, but inaccuracies are to be expected for wind directions deviating from the tangent to the flight path. M2 considers the change of airflow direction, but it does not consider the associated change in the angle of attack of the skis which additionally modifies drag and lift area time functions. M3 predicts the length effect for all wind directions within the plane of the flight trajectory without any mathematical simplification. Prediction errors of M3 are determined only by the quality of the input data: wind velocity, drag and lift area functions, take-off velocity, and weight. For comparing the three models, drag and lift area functions of an optimized reference jump were used. Results obtained with M2, which is much easier to handle than M3, did not deviate noticeably when compared to predictions of the reference model M3. Therefore, we suggest to use M2 in future applications. A comparison of M2 predictions with the FIS wind compensation system showed substantial discrepancies, for instance: in the first flight phase, tailwind can increase jump length, and headwind can decrease it; this is opposite of what had been anticipated before and is not considered in the current wind compensation system in ski jumping.}, language = {en} } @article{JungMuellerStaat2019, author = {Jung, Alexander and M{\"u}ller, Wolfram and Staat, Manfred}, title = {Optimization of the flight technique in ski jumping: the influence of wind}, number = {Early view}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jbiomech.2019.03.023}, year = {2019}, language = {en} } @article{JungStaat2019, author = {Jung, Alexander and Staat, Manfred}, title = {Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue}, series = {GAMM - Mitteilungen der Gesellschaft f{\"u}r Angewandte Mathematik und Mechanik}, volume = {42}, journal = {GAMM - Mitteilungen der Gesellschaft f{\"u}r Angewandte Mathematik und Mechanik}, number = {4}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2608}, doi = {10.1002/gamm.201900002}, pages = {11 Seiten}, year = {2019}, language = {en} } @article{JungStaat2020, author = {Jung, Alexander and Staat, Manfred}, title = {Erratum to "Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue" [GAMM-Mitteilungen, (2019), 42, 4, 10.1002/gamm.201900002]}, series = {GAMM-Mitteilungen}, volume = {43}, journal = {GAMM-Mitteilungen}, number = {4}, publisher = {Wiley-VCH GmbH}, address = {Weinheim}, issn = {1522-2608}, doi = {10.1002/gamm.202000011}, year = {2020}, language = {en} } @article{JungStaatMueller2013, author = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram}, title = {Flight style optimization in ski jumping on normal, large, and ski flying hills}, series = {Journal of biomechanics}, volume = {Vol. 47}, journal = {Journal of biomechanics}, number = {Iss. 3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2380 (E-Journal); 0021-9290 (Print)}, pages = {716 -- 722}, year = {2013}, language = {en} } @article{JungStaatMueller2018, author = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram}, title = {Corrigendum to "Flight style optimization in ski jumping on normal, large, and ski flying hills" [J. Biomech 47 (2014) 716-722]}, series = {Journals of Biomechanics}, journal = {Journals of Biomechanics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2018.02.001}, pages = {313}, year = {2018}, 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{KaulKoshkaryevArtmannetal.2008, author = {Kaul, D. K. and Koshkaryev, A. and Artmann, Gerhard and Barshtein, G. and Yedgar, S.}, title = {Additive effect of red blood cell rigidity and adherence to endothelial cells in inducing vascular resistance}, series = {American Journal of Physiology : Heart and Circulation Physiology . 295 (2008), H. 4}, volume = {295}, journal = {American Journal of Physiology : Heart and Circulation Physiology . 295 (2008), H. 4}, number = {4}, issn = {1522-1539}, pages = {H1788 -- H1793}, year = {2008}, language = {en} } @article{KetelhutBrueggeGoelletal.2020, author = {Ketelhut, Maike and Br{\"u}gge, G. M. and G{\"o}ll, Fabian and Braunstein, Bjoern and Albracht, Kirsten and Abel, Dirk}, title = {Adaptive iterative learning control of an industrial robot during neuromuscular training}, series = {IFAC PapersOnLine}, volume = {53}, journal = {IFAC PapersOnLine}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2020.12.741}, pages = {16468 -- 16475}, year = {2020}, abstract = {To prevent the reduction of muscle mass and loss of strength coming along with the human aging process, regular training with e.g. a leg press is suitable. However, the risk of training-induced injuries requires the continuous monitoring and controlling of the forces applied to the musculoskeletal system as well as the velocity along the motion trajectory and the range of motion. In this paper, an adaptive norm-optimal iterative learning control algorithm to minimize the knee joint loadings during the leg extension training with an industrial robot is proposed. The response of the algorithm is tested in simulation for patients with varus, normal and valgus alignment of the knee and compared to the results of a higher-order iterative learning control algorithm, a robust iterative learning control and a recently proposed conventional norm-optimal iterative learning control algorithm. Although significant improvements in performance are made compared to the conventional norm-optimal iterative learning control algorithm with a small learning factor, for the developed approach as well as the robust iterative learning control algorithm small steady state errors occur.}, language = {en} } @article{KetelhutGoellBraunsteinetal.2018, author = {Ketelhut, Maike and G{\"o}ll, Fabian and Braunstein, Bj{\"o}rn and Albracht, Kirsten and Abel, Dirk}, title = {Comparison of different training algorithms for the leg extension training with an industrial robot}, series = {Current Directions in Biomedical Engineering}, volume = {4}, journal = {Current Directions in Biomedical Engineering}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {2364-5504}, doi = {10.1515/cdbme-2018-0005}, pages = {17 -- 20}, year = {2018}, abstract = {In the past, different training scenarios have been developed and implemented on robotic research platforms, but no systematic analysis and comparison have been done so far. This paper deals with the comparison of an isokinematic (motion with constant velocity) and an isotonic (motion against constant weight) training algorithm. Both algorithms are designed for a robotic research platform consisting of a 3D force plate and a high payload industrial robot, which allows leg extension training with arbitrary six-dimensional motion trajectories. In the isokinematic as well as the isotonic training algorithm, individual paths are defined i n C artesian s pace by sufficient s upport p oses. I n t he i sotonic t raining s cenario, the trajectory is adapted to the measured force as the robot should only move along the trajectory as long as the force applied by the user exceeds a minimum threshold. In the isotonic training scenario however, the robot's acceleration is a function of the force applied by the user. To validate these findings, a simulative experiment with a simple linear trajectory is performed. For this purpose, the same force path is applied in both training scenarios. The results illustrate that the algorithms differ in the force dependent trajectory adaption.}, language = {en} } @article{KetelhutKolditzGoelletal.2019, author = {Ketelhut, Maike and Kolditz, Melanie and G{\"o}ll, Fabian and Braunstein, Bjoern and Albracht, Kirsten and Abel, Dirk}, title = {Admittance control of an industrial robot during resistance training}, series = {IFAC-PapersOnLine}, volume = {52}, journal = {IFAC-PapersOnLine}, number = {19}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2019.12.102}, pages = {223 -- 228}, year = {2019}, abstract = {Neuromuscular strength training of the leg extensor muscles plays an important role in the rehabilitation and prevention of age and wealth related diseases. In this paper, we focus on the design and implementation of a Cartesian admittance control scheme for isotonic training, i.e. leg extension and flexion against a predefined weight. For preliminary testing and validation of the designed algorithm an experimental research and development platform consisting of an industrial robot and a force plate mounted at its end-effector has been used. Linear, diagonal and arbitrary two-dimensional motion trajectories with different weights for the leg extension and flexion part are applied. The proposed algorithm is easily adaptable to trajectories consisting of arbitrary six-dimensional poses and allows the implementation of individualized trajectories.}, language = {en} } @article{KezerashviliDachwald2021, author = {Kezerashvili, Roman Ya and Dachwald, Bernd}, title = {Preface: Solar sailing: Concepts, technology, and missions II}, series = {Advances in Space Research}, volume = {67}, journal = {Advances in Space Research}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2021.01.037}, pages = {2559 -- 2560}, year = {2021}, language = {en} } @article{KnoxBruggemannGossmannetal.2020, author = {Knox, Ronald and Bruggemann, Andrea and Gossmann, Matthias and Thomas, Ulrich and Horv{\´a}th, Andr{\´a}s and Dragicevic, Elena and Stoelzle-Feix, Sonja and Fertig, Niels and Jung, Alexander and Raman, Aravind Hariharan and Staat, Manfred and Linder, Peter}, title = {Combining physiological relevance and throughput for in vitro cardiac contractility measurement}, series = {Biophysical Journal}, volume = {118}, journal = {Biophysical Journal}, number = {Issue 3, Supplement 1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0006-3495}, doi = {10.1016/j.bpj.2019.11.3104}, pages = {570a}, year = {2020}, abstract = {Despite increasing acceptance of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in safety pharmacology, controversy remains about the physiological relevance of existing in vitro models for their mechanical testing. We hypothesize that existing signs of immaturity of the cell models result from an improper mechanical environment. We cultured hiPSC-CMs in a 96-well format on hyperelastic silicone membranes imitating their native mechanical environment, resulting in physiological responses to compound stimuli.We validated cell responses on the FLEXcyte 96, with a set of reference compounds covering a broad range of cellular targets, including ion channel modulators, adrenergic receptor modulators and kinase inhibitors. Acute (10 - 30 min) and chronic (up to 7 days) effects were investigated. Furthermore, the measurements were complemented with electromechanical models based on electrophysiological recordings of the used cell types.hiPSC-CMs were cultured on freely-swinging, ultra-thin and hyperelastic silicone membranes. The weight of the cell culture medium deflects the membranes downwards. Rhythmic contraction of the hiPSC-CMs resulted in dynamic deflection changes which were quantified by capacitive distance sensing. The cells were cultured for 7 days prior to compound addition. Acute measurements were conducted 10-30 minutes after compound addition in standard culture medium. For chronic treatment, compound-containing medium was replaced daily for up to 7 days. Electrophysiological properties of the employed cell types were recorded by automated patch-clamp (Patchliner) and the results were integrated into the electromechanical model of the system.Calcium channel agonist S Bay K8644 and beta-adrenergic stimulator isoproterenol induced significant positive inotropic responses without additional external stimulation. Kinase inhibitors displayed cardiotoxic effects on a functional level at low concentrations. The system-integrated analysis detected alterations in beating shape as well as frequency and arrhythmic events and we provide a quantitative measure of these.}, language = {en} } @article{KodomskoiKotliarSchroederetal.2019, author = {Kodomskoi, Leonid and Kotliar, Konstantin and Schr{\"o}der, Andreas and Weiss, Michael and Hille, Konrad}, title = {Suture-Probe Canaloplasty as an Alternative to Canaloplasty using the iTrack™ Microcatheter}, series = {Journal of Glaucoma}, journal = {Journal of Glaucoma}, number = {Epub ahead of print}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1057-0829}, doi = {10.1097/IJG.0000000000001321}, year = {2019}, language = {en} } @article{KolditzAlbinAbeletal.2016, author = {Kolditz, Melanie and Albin, Thivaharan and Abel, Dirk and Fasse, Alessandro and Br{\"u}ggemann, Gert-Peter and Albracht, Kirsten}, title = {Evaluation of foot position and orientation as manipulated variables to control external knee adduction moments in leg extension training}, series = {Computer methods and programs in biomedicine}, volume = {171}, journal = {Computer methods and programs in biomedicine}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-2607}, doi = {10.1016/j.cmpb.2016.09.005}, pages = {81 -- 86}, year = {2016}, abstract = {Background and Objective Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed. Methods Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position. Results Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector. Conclusions The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training.}, 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{KoppSchmeetsGosauetal.2019, author = {Kopp, Alexander and Schmeets, Ralf and Gosau, Martin and Friedrich, Reinhard E. and Fuest, Sandra and Behbahani, Mehdi and Barbeck, Mike and Rutkowski, Rico and Burg, Simon and Kluwe, Lan and Henningsen, Anders}, title = {Production and Characterization of Porous Fibroin Scaffolds for Regenerative Medical Application}, series = {In Vivo}, volume = {33}, journal = {In Vivo}, number = {3}, issn = {1791-7549}, doi = {10.21873/invivo.11536}, pages = {757 -- 762}, year = {2019}, language = {en} } @article{KoppSchunckGosauetal.2020, author = {Kopp, Alexander and Schunck, Laura and Gosau, Martin and Smeets, Ralf and Burg, Simon and Fuest, Sandra and Kr{\"o}ger, Nadja and Zinser, Max and Krohn, Sebastian and Behbahani, Mehdi and K{\"o}pf, Marius and Lauts, Lisa and Rutkowski, Rico}, title = {Influence of the casting concentration on the mechanical and optical properties of Fa/CaCl2-derived silk fibroin membranes}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {18 art. no. 6704}, publisher = {MDPI}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms21186704}, year = {2020}, abstract = {In this study, we describe the manufacturing and characterization of silk fibroin membranes derived from the silkworm Bombyx mori. To date, the dissolution process used in this study has only been researched to a limited extent, although it entails various potential advantages, such as reduced expenses and the absence of toxic chemicals in comparison to other conventional techniques. Therefore, the aim of this study was to determine the influence of different fibroin concentrations on the process output and resulting membrane properties. Casted membranes were thus characterized with regard to their mechanical, structural and optical assets via tensile testing, SEM, light microscopy and spectrophotometry. Cytotoxicity was evaluated using BrdU, XTT, and LDH assays, followed by live-dead staining. The formic acid (FA) dissolution method was proven to be suitable for the manufacturing of transparent and mechanically stable membranes. The fibroin concentration affects both thickness and transparency of the membranes. The membranes did not exhibit any signs of cytotoxicity. When compared to other current scientific and technical benchmarks, the manufactured membranes displayed promising potential for various biomedical applications. Further research is nevertheless necessary to improve reproducible manufacturing, including a more uniform thickness, less impurity and physiological pH within the membranes.}, language = {en} } @article{KotliarBauerZamuraev2006, author = {Kotliar, Konstantin and Bauer, S. M. and Zamuraev, L. A.}, title = {Model of the transversely isotropic spherical layer for estimation of intraocular pressure changes after intravitreal injections / Bauer, S. M. ; Zamuraev, L. A. ; Kotliar, K. E.}, series = {Rossiiskii zhurnal biomekhaniki = Russian Journal of biomechanics. 10 (2006), H. 2}, journal = {Rossiiskii zhurnal biomekhaniki = Russian Journal of biomechanics. 10 (2006), H. 2}, publisher = {-}, isbn = {1812-5123}, pages = {41 -- 47}, year = {2006}, language = {en} } @article{KotliarBaumannVilseretal.2011, author = {Kotliar, Konstantin and Baumann, Marcus and Vilser, Walthard and Lanzl, Ines M.}, title = {Pulse wave velocity in retinal arteries of healthy volunteers}, series = {British Journal of Ophthalmology (eBJO)}, volume = {95}, journal = {British Journal of Ophthalmology (eBJO)}, number = {11}, publisher = {BMJ Publ. Group}, address = {London}, isbn = {1468-2079}, pages = {675 -- 679}, year = {2011}, language = {en} } @article{KotliarHanssenEberhardtetal.2013, author = {Kotliar, Konstantin and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Schmaderer, Christoph and Halle, Martin and Heemann, Uwe and Baumann, M.}, title = {Retinal pulse wave velocity in young male normotensive and mildly hypertensive subjects}, series = {Microcirculation}, journal = {Microcirculation}, publisher = {Wiley}, address = {Malden}, issn = {1549-8719}, year = {2013}, language = {en} } @article{KotliarHauserOrtneretal.2017, author = {Kotliar, Konstantin and Hauser, Christine and Ortner, Marion and Muggenthaler, Claudia and Diehl-Schmid, Janine and Angermann, Susanne and Hapfelmeier, Alexander and Schmaderer, Christoph and Grimmer, Timo}, title = {Altered neurovascular coupling as measured by optical imaging: a biomarker for Alzheimer's disease}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {2045-2322}, doi = {10.1038/s41598-017-13349-5}, pages = {1 -- 11}, year = {2017}, 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{KotliarKoshitzSvetlovaetal.2006, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlova, O. V. and Zaseeva, M. V.}, title = {Physiological principles of hypotensive therapy of open-angle glaucoma during presbyopic period. Part I Initial theoretical presuppositions, hypotheses and facts / Koshitz, I. N. ; Svetlova, O. V. ; Zaseeva, M. V. ; Shuhaev, S. V. ; Makarov, F. N. ; Kotli}, series = {Glaukoma (2006)}, journal = {Glaukoma (2006)}, publisher = {-}, pages = {35 -- 53}, year = {2006}, language = {en} } @article{KotliarKoshitzSvetlowaetal.2005, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlowa, O. V. and Makarov, F. N.}, title = {Biomechanical analysis of traditional and contemporary conceptions on pathogenesis of the primary open angle glaucoma / Koshitz, I. N. ; Svetlova, O. V. ; Kotliar, K. E. ; Makarov, F. N. ; Smolnikov, B. A.}, series = {Glaukoma (2005)}, journal = {Glaukoma (2005)}, publisher = {-}, pages = {41 -- 63}, year = {2005}, language = {en} } @article{KotliarKoshitzSvetlowaetal.2006, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlowa, O. V. and Zaseeva, M. V.}, title = {Physiological principles of hypotensive therapy of open-angle glaucoma during presbyopic period. Part II Promising algorithms of practical sparing applications / Koshitz, I. N. ; Svetlova, O. V. ; Zaseeva, M. V. ; Shuhaev, S. V. ; Makarov, F. N. ; Kotliar}, series = {Glaukoma (2006)}, journal = {Glaukoma (2006)}, publisher = {-}, pages = {51 -- 70}, year = {2006}, language = {en} } @article{KotliarKozlovaLanzl2009, author = {Kotliar, Konstantin and Kozlova, Tatiana V. and Lanzl, Ines M.}, title = {Postoperative aqueous outflow in the human eye after glaucoma filtration surgery: biofluidmechanical considerations}, series = {Biomedizinische Technik = Biomedical Engineering}, volume = {54}, journal = {Biomedizinische Technik = Biomedical Engineering}, number = {1}, publisher = {-}, isbn = {1862-278X}, pages = {14 -- 22}, year = {2009}, language = {en} } @article{KotliarLanzl2011, author = {Kotliar, Konstantin and Lanzl, Ines M.}, title = {Can vascular function be assessed by the interpretation of retinal vascular diameter changes?}, series = {Investigative Ophthalmology \& Visual Science, IOVS. 52 (2011), H. 1}, journal = {Investigative Ophthalmology \& Visual Science, IOVS. 52 (2011), H. 1}, publisher = {ARVO}, address = {Rockville, Md.}, isbn = {0146-0404}, pages = {635 -- 636}, year = {2011}, 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} } @article{KotliarLanzlMaieretal.2008, author = {Kotliar, Konstantin and Lanzl, Ines M. and Maier, Mathias and Feucht, Nikolaus}, title = {Intraocular pressure effects of pegaptanib (macugen) injections in patients with and without glaucoma / Lanzl, Ines M. ; Maier, Mathias ; Feucht, Nikolaus ; Lohmann, Chris P. ; Kotliar, Konstantin E.}, series = {American Journal of Ophthalmology . 145 (2008), H. 1}, journal = {American Journal of Ophthalmology . 145 (2008), H. 1}, publisher = {-}, isbn = {1879-1891}, pages = {185 -- 185}, year = {2008}, 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{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} } @article{KotliarMaierBaueretal.2008, author = {Kotliar, Konstantin and Maier, Mathias and Bauer, Svetlana and Feucht, Nikolaus and Lohmann, Chris and Lanzl, Ines}, title = {Intravitreal injection of triamcinolone acetonide and intraocular pressure: author's reply}, series = {Acta Ophthalmologica}, volume = {86}, journal = {Acta Ophthalmologica}, number = {6}, publisher = {-}, isbn = {1755-3768}, pages = {692 -- 693}, year = {2008}, language = {en} } @article{KotliarMogilevskiĭShiloetal.2008, author = {Kotliar, Konstantin and Mogilevskiĭ, A. Ia. and Shilo, A. V. and Panchekha, A. P.}, title = {[Chaotic non-linear dynamics of alpha-band of the EEg and organization of the cortical activity of P300 wave] / Mogilevskiĭ, A. Ia. ; Kotliar, K. E. ; Shilo, A. V. ; Panchekha, A. P.}, series = {Zhurnal vyssheĭ nervnoĭ deiatelnosti imeni I P Pavlova. 58 (2008), H. 5}, journal = {Zhurnal vyssheĭ nervnoĭ deiatelnosti imeni I P Pavlova. 58 (2008), H. 5}, publisher = {-}, isbn = {0044-4677}, pages = {562 -- 575}, year = {2008}, 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} } @article{KotliarNagelVilseretal.2008, author = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Lanzl, Ines M.}, title = {Functional in vivo assessment of retinal artery microirregularities in glaucoma / Kotliar, Konstantin E. ; Nagel, Edgar ; Vilser, Walthard ; Lanzl, Ines M.}, series = {Acta Ophthalmologica. 86 (2008), H. 4}, journal = {Acta Ophthalmologica. 86 (2008), H. 4}, publisher = {-}, isbn = {1755-3768}, pages = {424 -- 433}, year = {2008}, language = {en} } @article{KotliarNagelVilseretal.2010, author = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Seidova, Seid-Fatima and Lanzl, Ines}, title = {Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {51}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.09-3649}, pages = {2165 -- 2172}, year = {2010}, abstract = {Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation.}, language = {en} }