TY - JOUR A1 - Ringers, Christa A1 - Bialonski, Stephan A1 - Ege, Mert A1 - Solovev, Anton A1 - Hansen, Jan Niklas A1 - Jeong, Inyoung A1 - Friedrich, Benjamin M. A1 - Jurisch-Yaksi, Nathalie T1 - Novel analytical tools reveal that local synchronization of cilia coincides with tissue-scale metachronal waves in zebrafish multiciliated epithelia JF - eLife N2 - Motile cilia are hair-like cell extensions that beat periodically to generate fluid flow along various epithelial tissues within the body. In dense multiciliated carpets, cilia were shown to exhibit a remarkable coordination of their beat in the form of traveling metachronal waves, a phenomenon which supposedly enhances fluid transport. Yet, how cilia coordinate their regular beat in multiciliated epithelia to move fluids remains insufficiently understood, particularly due to lack of rigorous quantification. We combine experiments, novel analysis tools, and theory to address this knowledge gap. To investigate collective dynamics of cilia, we studied zebrafish multiciliated epithelia in the nose and the brain. We focused mainly on the zebrafish nose, due to its conserved properties with other ciliated tissues and its superior accessibility for non-invasive imaging. We revealed that cilia are synchronized only locally and that the size of local synchronization domains increases with the viscosity of the surrounding medium. Even though synchronization is local only, we observed global patterns of traveling metachronal waves across the zebrafish multiciliated epithelium. Intriguingly, these global wave direction patterns are conserved across individual fish, but different for left and right noses, unveiling a chiral asymmetry of metachronal coordination. To understand the implications of synchronization for fluid pumping, we used a computational model of a regular array of cilia. We found that local metachronal synchronization prevents steric collisions, i.e., cilia colliding with each other, and improves fluid pumping in dense cilia carpets, but hardly affects the direction of fluid flow. In conclusion, we show that local synchronization together with tissue-scale cilia alignment coincide and generate metachronal wave patterns in multiciliated epithelia, which enhance their physiological function of fluid pumping. Y1 - 2023 U6 - https://doi.org/10.7554/eLife.77701 SN - 2050-084X VL - 12 PB - eLife Sciences Publications ER - TY - JOUR A1 - Demirci, T. A1 - Trzewik, J. A1 - Linder, Peter A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Mechanical Stimulation of 3T3 Fibroblasts Activates Genes: ITGB5 and p53 Responses as Quantified on the mRNA Level JF - Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2 Y1 - 2004 SN - 0932-4666 SP - 1030 EP - 1031 ER - TY - JOUR A1 - Asante-Asamani, E.O. A1 - Kleefeld, Andreas A1 - Wade, B.A. T1 - A second-order exponential time differencing scheme for non-linear reaction-diffusion systems with dimensional splitting JF - Journal of Computational Physics N2 - A second-order L-stable exponential time-differencing (ETD) method is developed by combining an ETD scheme with approximating the matrix exponentials by rational functions having real distinct poles (RDP), together with a dimensional splitting integrating factor technique. A variety of non-linear reaction-diffusion equations in two and three dimensions with either Dirichlet, Neumann, or periodic boundary conditions are solved with this scheme and shown to outperform a variety of other second-order implicit-explicit schemes. An additional performance boost is gained through further use of basic parallelization techniques. KW - Exponential time differencing KW - Real distinct pole KW - Dimensional splitting KW - Reaction-diffusion systems KW - Matrix exponential Y1 - 2020 U6 - https://doi.org/10.1016/j.jcp.2020.109490 SN - 0021-9991 N1 - Corresponding author: Andreas Kleefeld VL - 415 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rausch, Valentin A1 - Harbrecht, Andreas A1 - Kahmann, Stephanie Lucina A1 - Fenten, Thomas A1 - Jovanovic, Nebojsa A1 - Hackl, Michael A1 - Müller, Lars P. A1 - Staat, Manfred A1 - Wegmann, Kilian T1 - Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws JF - The Journal of Hand Surgery N2 - Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties. Y1 - 2020 U6 - https://doi.org/10.1016/j.jhsa.2020.04.010 SN - 0363-5023 VL - 45 IS - 10 SP - 987.e1 EP - 987.e8 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Muschallik, Lukas A1 - Kipp, Carina Ronja A1 - Recker, Inga A1 - Bongaerts, Johannes A1 - Pohl, Martina A1 - Gelissen, Melanie A1 - Schöning, Michael Josef A1 - Selmer, Thorsten A1 - Siegert, Petra T1 - Synthesis of α-hydroxy ketones and vicinal diols with the Bacillus licheniformis DSM 13T butane-2, 3-diol dehydrogenase JF - Journal of Biotechnology N2 - The enantioselective synthesis of α-hydroxy ketones and vicinal diols is an intriguing field because of the broad applicability of these molecules. Although, butandiol dehydrogenases are known to play a key role in the production of 2,3-butandiol, their potential as biocatalysts is still not well studied. Here, we investigate the biocatalytic properties of the meso-butanediol dehydrogenase from Bacillus licheniformis DSM 13T (BlBDH). The encoding gene was cloned with an N-terminal StrepII-tag and recombinantly overexpressed in E. coli. BlBDH is highly active towards several non-physiological diketones and α-hydroxyketones with varying aliphatic chain lengths or even containing phenyl moieties. By adjusting the reaction parameters in biotransformations the formation of either the α-hydroxyketone intermediate or the diol can be controlled. Y1 - 2020 SN - 2590-1559 U6 - https://doi.org/10.1016/j.jbiotec.2020.09.016 VL - 202 IS - Vol. 324 SP - 61 EP - 70 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hunker, Jan L. A1 - Gossmann, Matthias A1 - Raman, Aravind Hariharan A1 - Linder, Peter T1 - Artificial neural networks in cardiac safety assessment: Classification of chemotherapeutic compound effects on hiPSC-derived cardiomyocyte contractility JF - Journal of Pharmacological and Toxicological Methods Y1 - 2021 U6 - https://doi.org/10.1016/j.vascn.2021.107044 SN - 1056-8719 VL - 111 IS - Article number 107044 PB - Elsevier CY - New York ER - TY - BOOK A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül A1 - Zhubanova, Azhar A. A1 - Digel, Ilya ED - Artmann, Gerhard ED - Temiz Artmann, Aysegül ED - Zhubanova, Azhar A. ED - Digel, Ilya T1 - Biological, physical and technical basics of cell engineering Y1 - 2018 SN - 978-981-10-7903-0 PB - Springer CY - Singapore ER - TY - JOUR A1 - Staat, Manfred A1 - Schwartz, M. A1 - Lang, H. A1 - Wirtz, K. A1 - Heitzer, M. T1 - Design by Analysis of Pressure Components by non-linear Optimization JF - The 10th International Conference on Pressure Vessel Technology, July 7-10, 2003, Vienna, Austria, Proceedings ICPVT-10 / Zeman, J. L. [ed] Y1 - 2003 SN - 3950152814 SP - 59 EP - 65 PB - ÖGS, Österreichische Gesellschaft für Schweißtechnik CY - Wien ER - TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. T1 - Limit and Shakedown Analysis with Uncertain Data JF - Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed] Y1 - 2002 SN - 3-540-42889-5 SP - 241 EP - 254 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Stadler, Andreas M. A1 - Zerlin, Kay A1 - Digel, Ilya A1 - Büldt, Georg A1 - Zaccai, Guiseppe A1 - Artmann, Gerhard T1 - Dynamics and interactions of hemoglobin in red blood cells JF - Tissue Engineering Part A. 14 (2008), H. 5 Y1 - 2008 SN - 1937-3341 N1 - TERMIS EU 2008 Porto Meeting June 22–26, 2008 Porto Congress Center–Alfândega Portugal SP - 724 EP - 724 ER - TY - JOUR A1 - Akimbekov, Nuraly S. A1 - Digel, Ilya A1 - Tastambek, K. T. A1 - Zhubanova, A. A. T1 - Biocompatibility of carbonized rice husk with a rat heart cells line H9c2 JF - Experimental Biology Y1 - 2013 SN - 1563-0218 N1 - Original in russischer Sprache VL - 59 IS - 3/1 SP - 23 EP - 25 ER - TY - JOUR A1 - Bhattarai, Aroj A1 - Staat, Manfred T1 - A computational study of organ relocation after laparoscopic pectopexy to repair posthysterectomy vaginal vault prolapse JF - Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization Y1 - 2019 U6 - https://doi.org/10.1080/21681163.2019.1670095 SN - 2168-1171 PB - Taylor & Francis CY - London 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 - https://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 - Vu, Duc Khoi A1 - Staat, Manfred A1 - Tran, Ich Thinh T1 - Analysis of pressure equipment by application of the primal-dual theory of shakedown JF - Communications in Numerical Methods in Engineering. 23 (2007), H. 3 Y1 - 2007 SN - 1069-8299 SP - 213 EP - 225 ER - TY - JOUR A1 - Staat, Manfred A1 - Vu, Khoi Duc T1 - Limit loads of circumferentially flawed pipes and cylindrical vessels under internal pressure JF - International Journal of Pressure Vessels and Piping. 83 (2006), H. 3 Y1 - 2006 SN - 0308-0161 SP - 188 EP - 196 ER - TY - CHAP A1 - Tran, N. T. A1 - Tran, Thanh Ngoc A1 - Matthies, M. G. A1 - Stavroulakis, G. E. A1 - Staat, Manfred T1 - Shakedown Analysis Under Stochastic Uncertainty by Chance Constrained Programming T2 - Advances in Direct Methods for Materials and Structures N2 - In this paper we propose a stochastic programming method to analyse limit and shakedown of structures under uncertainty condition of strength. Based on the duality theory, the shakedown load multiplier formulated by the kinematic theorem is proved actually to be the dual form of the shakedown load multiplier formulated by static theorem. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) with three-node linear triangular elements is used for structural analysis. Y1 - 2017 SN - 978-3-319-59810-9 U6 - https://doi.org/10.1007/978-3-319-59810-9_6 SP - 85 EP - 103 PB - Springer CY - Cham ER - TY - JOUR A1 - Jung, Alexander A1 - Staat, Manfred T1 - Erratum to "Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue" [GAMM-Mitteilungen, (2019), 42, 4, 10.1002/gamm.201900002] JF - GAMM-Mitteilungen Y1 - 2020 U6 - https://doi.org/10.1002/gamm.202000011 SN - 1522-2608 N1 - Refers to: Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue. Alexander Jung, Manfred Staat. Volume 42, Issue 4. GAMM-Mitteilungen, 2019. https://doi.org/10.1002/gamm.201900002 VL - 43 IS - 4 PB - Wiley-VCH GmbH CY - Weinheim ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Staat, Manfred ED - Fernandes, P.R. ED - Tavares, J. M. T1 - Pectopexy to repair vaginal vault prolapse: a finite element approach T2 - Proceedings CMBBE 2018 N2 - The vaginal prolapse after hysterectomy (removal of the uterus) is often associated with the prolapse of the vaginal vault, rectum, bladder, urethra or small bowel. Minimally invasive surgery such as laparoscopic sacrocolpopexy and pectopexy are widely performed for the treatment of the vaginal prolapse with weakly supported vaginal vault after hysterectomy using prosthetic mesh implants to support (or strengthen) lax apical ligaments. Implants of different shape, size and polymers are selected depending on the patient’s anatomy and the surgeon’s preference. In this computational study on pectopexy, DynaMesh®-PRP soft, GYNECARE GYNEMESH® PS Nonabsorbable PROLENE® soft and Ultrapro® are tested in a 3D finite element model of the female pelvic floor. The mesh model is implanted into the extraperitoneal space and sutured to the vaginal stump with a bilateral fixation to the iliopectineal ligament at both sides. Numerical simulations are conducted at rest, after surgery and during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues and prosthetic meshes are modeled as incompressible, isotropic hyperelastic materials. The positions of the organs are calculated with respect to the pubococcygeal line (PCL) for female pelvic floor at rest, after repair and during Valsalva maneuver using the three meshes. Y1 - 2018 N1 - 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization. CMBBE 2018. 26-29 March 2018, Lisbon, Portugal ER - TY - CHAP A1 - Jung, Alexander A1 - Staat, Manfred ED - Erni, Daniel T1 - Computing olympic gold: Ski jumping as an example T2 - 1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen Y1 - 2016 SN - 978-3-940402-06-6 U6 - https://doi.org/10.17185/duepublico/40821 SP - 54 EP - 55 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - JOUR A1 - Rausch, Valentin A1 - Kahmann, Stephanie Lucina A1 - Baltschun, Christoph A1 - Staat, Manfred A1 - Müller, Lars P. A1 - Wegmann, Kilian T1 - Pressure distribution to the distal biceps tendon at the radial tuberosity: a biomechanical study JF - The Journal of Hand Surgery N2 - Purpose Mechanical impingement at the narrow radioulnar space of the tuberosity is believed to be an etiological factor in the injury of the distal biceps tendon. The aim of the study was to compare the pressure distribution at the proximal radioulnar space between 2 fixation techniques and the intact state. Methods Six right arms and 6 left arms from 5 female and 6 male frozen specimens were used for this study. A pressure transducer was introduced at the height of the radial tuberosity with the intact distal biceps tendon and after 2 fixation methods: the suture-anchor and the cortical button technique. The force (N), maximum pressure (kPa) applied to the radial tuberosity, and the contact area (mm²) of the radial tuberosity with the ulna were measured and differences from the intact tendon were detected from 60° supination to 60° pronation in 15° increments with the elbow in full extension and in 45° and 90° flexion of the elbow. Results With the distal biceps tendon intact, the pressures during pronation were similar regardless of extension and flexion and were the highest at 60° pronation with 90° elbow flexion (23.3 ± 53.5 kPa). After repair of the tendon, the mean peak pressure, contact area, and total force showed an increase regardless of the fixation technique. Highest peak pressures were found using the cortical button technique at 45° flexion of the elbow and 60° pronation. These differences were significantly different from the intact tendon. The contact area was significantly larger in full extension and 15°, 30°, and 60° pronation using the cortical button technique. Conclusions Pressures on the distal biceps tendon at the radial tuberosity increase during pronation, especially after repair of the tendon. Clinical relevance Mechanical impingement could play a role in both the etiology of primary distal biceps tendon ruptures and the complications occurring after fixation of the tendon using certain techniques. Y1 - 2020 U6 - https://doi.org/10.1016/j.jhsa.2020.01.006 SN - 0363-5023 VL - 45 IS - 8 SP - 776.e1 EP - 776.e9 PB - Elsevier CY - Amsterdam ER -