TY - JOUR A1 - Jahnke, Siegfried A1 - Menzel, Marion I. A1 - Dusschoten, Dagmar van A1 - Roeb, Gerhard W. A1 - Bühler, Jonas A1 - Minwuyelet, Senay A1 - Blümler, Peter A1 - Temperton, Vicky M. A1 - Hombach, Thomas A1 - Streun, Matthias A1 - Beer, Simone A1 - Khodaverdi, Maryam A1 - Ziemons, Karl A1 - Coenen, Heinz H. A1 - Schurr, Ulrich T1 - Combined MRI–PET dissects dynamic changes in plant structures and functions JF - The Plant Journal N2 - Unravelling the factors determining the allocation of carbon to various plant organs is one of the great challenges of modern plant biology. Studying allocation under close to natural conditions requires non-invasive methods, which are now becoming available for measuring plants on a par with those developed for humans. By combining magnetic resonance imaging (MRI) and positron emission tomography (PET), we investigated three contrasting root/shoot systems growing in sand or soil, with respect to their structures, transport routes and the translocation dynamics of recently fixed photoassimilates labelled with the short-lived radioactive carbon isotope 11C. Storage organs of sugar beet (Beta vulgaris) and radish plants (Raphanus sativus) were assessed using MRI, providing images of the internal structures of the organs with high spatial resolution, and while species-specific transport sectoralities, properties of assimilate allocation and unloading characteristics were measured using PET. Growth and carbon allocation within complex root systems were monitored in maize plants (Zea mays), and the results may be used to identify factors affecting root growth in natural substrates or in competition with roots of other plants. MRI–PET co-registration opens the door for non-invasive analysis of plant structures and transport processes that may change in response to genomic, developmental or environmental challenges. It is our aim to make the methods applicable for quantitative analyses of plant traits in phenotyping as well as in understanding the dynamics of key processes that are essential to plant performance. Y1 - 2009 SN - 1365-313X VL - 59 IS - 4 SP - 634 EP - 644 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Musholt, Petra B. A1 - Schöndorf, Thomas A1 - Pfützner, Andreas A1 - Hohberg, Cloth A1 - Kleine, Iris A1 - Fuchs, Winfried A1 - Hehenwarter, Silvia A1 - Dikta, Gerhard A1 - Kerschgens, Benedikt A1 - Forst, Thomas T1 - Combined Pioglitazone and Metformin Treatment Maintains the Beneficial Effect of Short-Term Insulin Infusion in Patients with Type 2 Diabetes: Results from a Pilot Study JF - Journal of Diabetes Science and Technology. 3 (2009), H. 6 Y1 - 2009 SN - 1932-2968 SP - 1442 EP - 1450 PB - Sage Publishing CY - London ER - TY - JOUR A1 - Engelmann, Ulrich M. A1 - Roeth, Anjali A.J. A1 - Eberbeck, Dietmar A1 - Buhl, Eva Miriam A1 - Neumann, Ulf Peter A1 - Schmitz-Rode, Thomas A1 - Slabu, Ioana T1 - Combining Bulk Temperature and Nanoheating Enables Advanced Magnetic Fluid Hyperthermia Efficacy on Pancreatic Tumor Cells JF - Scientific Reports N2 - Many efforts are made worldwide to establish magnetic fluid hyperthermia (MFH) as a treatment for organ-confined tumors. However, translation to clinical application hardly succeeds as it still lacks of understanding the mechanisms determining MFH cytotoxic effects. Here, we investigate the intracellular MFH efficacy with respect to different parameters and assess the intracellular cytotoxic effects in detail. For this, MiaPaCa-2 human pancreatic tumor cells and L929 murine fibroblasts were loaded with iron-oxide magnetic nanoparticles (MNP) and exposed to MFH for either 30 min or 90 min. The resulting cytotoxic effects were assessed via clonogenic assay. Our results demonstrate that cell damage depends not only on the obvious parameters bulk temperature and duration of treatment, but most importantly on cell type and thermal energy deposited per cell during MFH treatment. Tumor cell death of 95% was achieved by depositing an intracellular total thermal energy with about 50% margin to damage of healthy cells. This is attributed to combined intracellular nanoheating and extracellular bulk heating. Tumor cell damage of up to 86% was observed for MFH treatment without perceptible bulk temperature rise. Effective heating decreased by up to 65% after MNP were internalized inside cells. Y1 - 2018 U6 - http://dx.doi.org/10.1038/s41598-018-31553-9 SN - 2045-2322 VL - 8 IS - 1 SP - Article number 13210 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Knox, Ronald A1 - Bruggemann, Andrea A1 - Gossmann, Matthias A1 - Thomas, Ulrich A1 - Horváth, András A1 - Dragicevic, Elena A1 - Stoelzle-Feix, Sonja A1 - Fertig, Niels A1 - Jung, Alexander A1 - Raman, Aravind Hariharan A1 - Staat, Manfred A1 - Linder, Peter T1 - Combining physiological relevance and throughput for in vitro cardiac contractility measurement JF - Biophysical Journal N2 - 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. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.bpj.2019.11.3104 SN - 0006-3495 N1 - Raman, Arayind Hariharan im Artikel unter dem Namen: Raman, Alexander H. VL - 118 IS - Issue 3, Supplement 1 SP - 570a PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Engelmann, Ulrich M. A1 - Shalaby, Ahmed A1 - Shasha, Carolyn A1 - Krishnan, Kannan M. A1 - Krause, Hans-Joachim T1 - Comparative modeling of frequency mixing measurements of magnetic nanoparticles using micromagnetic simulations and Langevin theory JF - Nanomaterials N2 - Dual frequency magnetic excitation of magnetic nanoparticles (MNP) enables enhanced biosensing applications. This was studied from an experimental and theoretical perspective: nonlinear sum-frequency components of MNP exposed to dual-frequency magnetic excitation were measured as a function of static magnetic offset field. The Langevin model in thermodynamic equilibrium was fitted to the experimental data to derive parameters of the lognormal core size distribution. These parameters were subsequently used as inputs for micromagnetic Monte-Carlo (MC)-simulations. From the hysteresis loops obtained from MC-simulations, sum-frequency components were numerically demodulated and compared with both experiment and Langevin model predictions. From the latter, we derived that approximately 90% of the frequency mixing magnetic response signal is generated by the largest 10% of MNP. We therefore suggest that small particles do not contribute to the frequency mixing signal, which is supported by MC-simulation results. Both theoretical approaches describe the experimental signal shapes well, but with notable differences between experiment and micromagnetic simulations. These deviations could result from Brownian relaxations which are, albeit experimentally inhibited, included in MC-simulation, or (yet unconsidered) cluster-effects of MNP, or inaccurately derived input for MC-simulations, because the largest particles dominate the experimental signal but concurrently do not fulfill the precondition of thermodynamic equilibrium required by Langevin theory. KW - Magnetic nanoparticles KW - Frequency mixing magnetic detection KW - Langevin theory KW - Micromagnetic simulation KW - Nonequilibrium dynamics Y1 - 2021 SN - 2079-4991 U6 - http://dx.doi.org/10.3390/nano11051257 N1 - This article belongs to the Special Issue Applications and Properties of Magnetic Nanoparticles VL - 11 IS - 5 SP - 1 EP - 16 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ketelhut, Maike A1 - Göll, Fabian A1 - Braunstein, Björn A1 - Albracht, Kirsten A1 - Abel, Dirk T1 - Comparison of different training algorithms for the leg extension training with an industrial robot JF - Current Directions in Biomedical Engineering N2 - 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. KW - Rehabilitation Technology and Prosthetics KW - Surgical Navigation and Robotics Y1 - 2018 U6 - http://dx.doi.org/10.1515/cdbme-2018-0005 SN - 2364-5504 VL - 4 IS - 1 SP - 17 EP - 20 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Hillen, Walter T1 - Comparison of e+e− annihilation with QCD and determination of the strong coupling constant . TASSO Collaboration JF - Physics Letters B. 94 (1980), H. 3 Y1 - 1980 SN - 0370-2693 SP - 437 EP - 443 ER - TY - JOUR A1 - Schieren, Mark A1 - Kleinschmidt, Joris A1 - Schmutz, Axel A1 - Loop, Torsten A1 - Gatzweiler, Karl-Heinz A1 - Staat, Manfred A1 - Wappler, Frank A1 - Defosse, Jerome T1 - Comparison of forces acting on maxillary incisors during tracheal intubation with different laryngoscopy techniques: a blinded manikin study JF - Anaesthesia Y1 - 2019 SN - 1365-2044 U6 - http://dx.doi.org/10.1111/anae.14815 N1 - Die Anhänge "Table S1 (Impact of sex and level of training on dental force. Results presented as median (IQR [range]) and n (%))" und "Appendix S1 (Measurement technique.)" stehen unter "Supporting Information" zum Download bereit. VL - 74 IS - 12 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Ziemons, Karl T1 - Comparison of forward hadrons produced in muon interactions on nuclear targets and deuterium JF - Zeitschrift für Physik C Particles and Fields N2 - Differential multiplicities of forward produced hadrons in deep inelastic muon scattering on nuclear targets have been compared with those from deuterium. The ratios are observed to increase towards unity as the virtual photon energy increases with no significant dependence on the other muon kinematic variables. The hadron transverse momentum distribution is observed to be broadened in nuclear targets. The dependence on the remaining hadron variables is investigated and the results are discussed in the framework of intranuclear interaction models and in the context of the EMC effect. Y1 - 1991 SN - 1431-5858 N1 - European Muon Collaboration VL - 52 IS - 1 SP - 1 EP - 11 ER - TY - CHAP A1 - Takenaga, Shoko A1 - Werner, Frederik A1 - Sawada, Kazuaki A1 - Schöning, Michael Josef T1 - Comparison of label-free ACh image sensors based on CCD and LAPS Y1 - 2012 SN - 978-3-9813484-2-2 U6 - http://dx.doi.org/10.5162/IMCS2012/4.2.6 SP - 356 EP - 359 ER - TY - JOUR A1 - Werner, Frederik A1 - Takenaga, Shoko A1 - Taki, Hidenori A1 - Sawada, Kazuaki A1 - Schöning, Michael Josef T1 - Comparison of label-free ACh-imaging sensors based on CCD and LAPS JF - Sensors and Actuators B: Chemical (2012) N2 - Semiconductor-based chemical imaging sensors, like the light-addressable potentiometric sensor (LAPS) or the pH-imaging sensor based on a charge-coupled device (CCD), are becoming a powerful tool for label-free imaging of biological phenomena. We have proposed a polyion-based enzymatic membrane to develop an acetylcholine (ACh) imaging sensor for neural cell-activity observations. In this study, a CCD-type ACh-imaging sensor and a LAPS-type ACh-imaging sensor were fabricated and the prospect of both sensors was clarified by making a comparison of their basic characteristics. Y1 - 2013 SN - 0925-4005 VL - 177 SP - 745 EP - 752 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kaminsky, Randolph A1 - Weber, Hans-Joachim A1 - Simons, Antoine A1 - Kallweit, Stephan A1 - Kramm, K. A1 - Verdonck, Pascale T1 - Comparison of the flow downstream two prototypes of a new monoleaflet artificial aortic heart valve by means of PIV visualization JF - Computer methods in biomechanics and biomedical engineering. 8 (2005), H. 4, Suppl. 1 Y1 - 2005 SN - 1476-8259 SP - 159 EP - 160 ER - TY - JOUR A1 - Nguyen-Xuan, H. A1 - Rabczuk, T. A1 - Nguyen-Thoi, T. A1 - Tran, Thanh Ngoc A1 - Nguyen-Thanh, N. T1 - Computation of limit and shakedown loads using a node-based smoothed finite element method JF - International Journal for Numerical Methods in Engineering N2 - This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node-based smoothed FEM in combination with a primal–dual algorithm. An associated primal–dual form based on the von Mises yield criterion is adopted. The primal-dual algorithm together with a Newton-like iteration are then used to solve this associated primal–dual form to determine simultaneously both approximate upper and quasi-lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods. Y1 - 2011 U6 - http://dx.doi.org/10.1002/nme.3317 SN - 1097-0207 VL - 90 IS - 3 SP - 287 EP - 310 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Computational Analysis of Pelvic Floor Dysfunction T2 - Women's Health and Biomechanics N2 - Pelvic floor dysfunction (PFD) is characterized by the failure of the levator ani (LA) muscle to maintain the pelvic hiatus, resulting in the descent of the pelvic organs below the pubococcygeal line. This chapter adopts the modified Humphrey material model to consider the effect of the muscle fiber on passive stretching of the LA muscle. The deformation of the LA muscle subjected to intra-abdominal pressure during Valsalva maneuver is compared with the magnetic resonance imaging (MRI) examination of a nulliparous female. Numerical result shows that the fiber-based Humphrey model simulates the muscle behavior better than isotropic constitutive models. Greater posterior movement of the LA muscle widens the levator hiatus due to lack of support from the anococcygeal ligament and the perineal structure as a consequence of birth-related injury and aging. Old and multiparous females with uncontrolled urogenital and rectal hiatus tend to develop PFDs such as prolapse and incontinence. KW - Pelvic muscle KW - Muscle fibers KW - Passive stretching KW - Pelvic floor dysfunction Y1 - 2018 SN - 978-3-319-71574-2 U6 - http://dx.doi.org/10.1007/978-3-319-71574-2_17 N1 - Lecture Notes in Computational Vision and Biomechanics, vol 29 SP - 217 EP - 230 PB - Springer CY - Cham ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Waluga, C. A1 - Arlt, S. A1 - Behr, M. A1 - Mottaghy, K. T1 - Computational Analysis of Platelet Aggregation in a Taylor-Couette System JF - The International Journal of Artificial Organs. 31 (2008), H. 7 Y1 - 2008 SN - 0391-3988 N1 - Posterpresentation ; European Society of Artificial Organs (ESAO), Geneva, Switzerland SP - 643 ER - TY - JOUR A1 - Bhattarai, Aroj A1 - Staat, Manfred T1 - Computational comparison of different textile implants to correct apical prolapse in females JF - Current Directions in Biomedical Engineering N2 - Prosthetic textile implants of different shapes, sizes and polymers are used to correct the apical prolapse after hysterectomy (removal of the uterus). The selection of the implant before or during minimally invasive surgery depends on the patient’s anatomical defect, intended function after reconstruction and most importantly the surgeon’s preference. Weakness or damage of the supporting tissues during childbirth, menopause or previous pelvic surgeries may put females in higher risk of prolapse. Numerical simulations of reconstructed pelvic floor with weakened tissues and organ supported by textile product models: DynaMesh®-PRS soft, DynaMesh®-PRP soft and DynaMesh®-CESA from FEG Textiletechnik mbH, Germany are compared. Y1 - 2018 U6 - http://dx.doi.org/10.1515/cdbme-2018-0159 VL - 4 IS - 1 SP - 661 EP - 664 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Malinowski, Daniel A1 - Fournier, Yvan A1 - Horbach, Andreas A1 - Frick, Michael A1 - Magliani, Mirko A1 - Kalverkamp, Sebastian A1 - Hildinger, Martin A1 - Spillner, Jan A1 - Behbahani, Mehdi A1 - Hima, Flutura T1 - Computational fluid dynamics analysis of endoluminal aortic perfusion JF - Perfusion N2 - Introduction: In peripheral percutaneous (VA) extracorporeal membrane oxygenation (ECMO) procedures the femoral arteries perfusion route has inherent disadvantages regarding poor upper body perfusion due to watershed. With the advent of new long flexible cannulas an advancement of the tip up to the ascending aorta has become feasible. To investigate the impact of such long endoluminal cannulas on upper body perfusion, a Computational Fluid Dynamics (CFD) study was performed considering different support levels and three cannula positions. Methods: An idealized literature-based- and a real patient proximal aortic geometry including an endoluminal cannula were constructed. The blood flow was considered continuous. Oxygen saturation was set to 80% for the blood coming from the heart and to 100% for the blood leaving the cannula. 50% and 90% venoarterial support levels from the total blood flow rate of 6 l/min were investigated for three different positions of the cannula in the aortic arch. Results: For both geometries, the placement of the cannula in the ascending aorta led to a superior oxygenation of all aortic blood vessels except for the left coronary artery. Cannula placements at the aortic arch and descending aorta could support supra-aortic arteries, but not the coronary arteries. All positions were able to support all branches with saturated blood at 90% flow volume. Conclusions: In accordance with clinical observations CFD analysis reveals, that retrograde advancement of a long endoluminal cannula can considerably improve the oxygenation of the upper body and lead to oxygen saturation distributions similar to those of a central cannulation. KW - computational fluid dynamics analysis KW - simulation KW - endoluminal KW - aortic perfusion KW - extracorporeal membrane oxygenation Y1 - 2022 U6 - http://dx.doi.org/10.1177/02676591221099809 SN - 1477-111X VL - 0 IS - 0 SP - 1 EP - 8 PB - Sage CY - London 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 - BOOK A1 - Grotendorst, Johannes T1 - Computational Nanoscience: Do it yourself! : winter school, 14 - 22 February 2006, Forschungszentrum Jülich, Germany ; lecture notes / Grotendorst, Johannes Y1 - 2006 SN - 3-00-017350-1 N1 - NIC series ; 31 ; Forschungszentrum / John-von-Neumann-Institut für Computing PB - NIC CY - Jülich ER - TY - CHAP A1 - Voronkova, Eva B. A1 - Bauer, Svetlana M. A1 - Kotliar, Konstantin T1 - Computer simulation of the cornea-scleral shell as applied to pressure-volume relationship in the human eye T2 - 2014 International Conference on Computer Technologies in Physical and Engineering Applications : ICCTPEA 2014 : proceedings : June 30 2014-July 4 2014, St. Petersburg Y1 - 2014 SN - 978-1-4799-5315-8 SP - 204 EP - 205 ER -