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  - CHAP
A1  - Engelmann, Ulrich M.
A1  - Shasha, Carolyn
A1  - Slabu, Ioana
T1  - Magnetic nanoparticle relaxation in biomedical application: focus on simulating nanoparticle heating
T2  - Magnetic nanoparticles in human health and medicine
Y1  - 2021
SN  - 978-1-119-75467-1
SP  - 327
EP  - 354
PB  - Wiley-Blackwell
CY  - Hoboken, New Jeersey
ER  - 
TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Shasha, Carolyn
A1  - Teeman, Eric
A1  - Slabu, Iona
A1  - Krishnan, Kannan M.
T1  - Predicting size-dependent heating efficiency of magnetic nanoparticles from experiment and stochastic Néel-Brown Langevin simulation
JF  - Journal of Magnetism and Magnetic Materials
Y1  - 2019
U6  - http://dx.doi.org/10.1016/j.jmmm.2018.09.041
SN  - 0304-8853
VL  - 471
IS  - 1
SP  - 450
EP  - 456
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Simsek, Beril
A1  - Shalaby, Ahmed
A1  - Krause, Hans-Joachim
T1  - Key contributors to signal generation in frequency mixing magnetic detection (FMMD): an in silico study
JF  - Sensors
N2  - Frequency mixing magnetic detection (FMMD) is a sensitive and selective technique to detect magnetic nanoparticles (MNPs) serving as probes for binding biological targets. Its principle relies on the nonlinear magnetic relaxation dynamics of a particle ensemble interacting with a dual frequency external magnetic field. In order to increase its sensitivity, lower its limit of detection and overall improve its applicability in biosensing, matching combinations of external field parameters and internal particle properties are being sought to advance FMMD. In this study, we systematically probe the aforementioned interaction with coupled Néel–Brownian dynamic relaxation simulations to examine how key MNP properties as well as applied field parameters affect the frequency mixing signal generation. It is found that the core size of MNPs dominates their nonlinear magnetic response, with the strongest contributions from the largest particles. The drive field amplitude dominates the shape of the field-dependent response, whereas effective anisotropy and hydrodynamic size of the particles only weakly influence the signal generation in FMMD. For tailoring the MNP properties and parameters of the setup towards optimal FMMD signal generation, our findings suggest choosing large particles of core sizes dc > 25 nm nm with narrow size distributions (σ < 0.1) to minimize the required drive field amplitude. This allows potential improvements of FMMD as a stand-alone application, as well as advances in magnetic particle imaging, hyperthermia and magnetic immunoassays.
KW  - key performance indicators
KW  - magnetic biosensing
KW  - coupled Néel–Brownian relaxation dynamics
KW  - frequency mixing magnetic detection
KW  - magnetic relaxation
KW  - micromagnetic simulation
KW  - magnetic nanoparticles
Y1  - 2024
U6  - http://dx.doi.org/10.3390/s24061945
SN  - 1424-8220
N1  - This article belongs to the Special Issue "Advances in Magnetic Sensors and Their Applications"
VL  - 24
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Erbayraktar, Zubeyde
A1  - Yilmaz, Osman
A1  - Temiz Artmann, Aysegül
A1  - Cehreli, Ruksan
A1  - Coker, Canan
T1  - Effects of Selenium Supplementation on Antioxidant Defense and Glucose Homeostasis in Experimental Diabetes Mellitus
JF  - Biological Trace Element Research
Y1  - 2007
SN  - 1559-0720
VL  - 118
IS  - 3
SP  - 217
EP  - 226
ER  - 
TY  - JOUR
A1  - Erki, I.
A1  - Kleines, H.
A1  - Ziemons, Karl
A1  - Zwoll, K.
ED  - Lehmann, Thomas
T1  - Interaktives System zur Darstellung funktionaler Bilddaten
JF  - Bildverarbeitung für die Medizin : Algorithmen - Systeme - Anwendungen
Y1  - 1997
SN  - 3-86073-519-5
N1  - Proceedings des Aachener Workshops am 8. u. 9. November 1996 ; PP_002 Posterpräsentation
SP  - 249
EP  - 254
PB  - Verl. der. Augustinus-Buchh.
CY  - Aachen
ER  - 
TY  - JOUR
A1  - Ermelenko, Y.
A1  - Yoshinobu, T
A1  - Mourzina, Y.
A1  - Levichev, S.
A1  - Furuichi, K.
A1  - Vlasov, Y.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Photocurable membranes for ion-selective light-addressable potentiometric sensors
JF  - Sensors and Actuators B. 85 (2002), H. 1-2
Y1  - 2002
SN  - 0925-4005
SP  - 79
EP  - 85
ER  - 
TY  - JOUR
A1  - Ermelenko, Y.
A1  - Yoshinobu, T.
A1  - Mourzina, Y.
A1  - Furuichi, K.
A1  - Iwasaki, H.
A1  - Vlasov, Y.
A1  - Schöning, Michael Josef
T1  - Technology of photocurable polymeric membranes for integrated LAPS
JF  - Proceedings of the 5th East Asian Conference on Chemical Sensors; the 33rd Chemical Sensor Symposium : December 4 - 7, 2001, Huis Ten Bosch, Sasebo-shi, Nagasaki, Japan / Japan Association of Chemical Sensors; the Electrochemical Society of Japan
Y1  - 2001
N1  - Chemical sensors; 17.2001 Suppl. B; East Asian Conference on Chemical Sensors ; (5, 2001; Nagasaki)
SP  - 66
EP  - 68
PB  - Japan Association of Chemical Sensors
CY  - Kasuga, Fukuoka-ken
ER  - 
TY  - JOUR
A1  - Ermelenko, Y.
A1  - Yoshinobu, T.
A1  - Mourzina, Y.
A1  - Furuichi, K.
A1  - Levichev, S.
A1  - Vlasov, Y.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Lithium sensor based on the laser scanning semiconductor transducer
JF  - Analytica Chimica Acta. 459 (2002), H. 1
Y1  - 2002
SN  - 0378-4304
SP  - 1
EP  - 9
ER  - 
TY  - JOUR
A1  - Ermelenko, Y.
A1  - Yoshinobu, T.
A1  - Mourzina, Y.
A1  - Schöning, Michael Josef
A1  - Furuichi, K.
A1  - Levichev, S.
A1  - Vlasov, Y.
A1  - Iwasaki, H.
T1  - The double K+/Ca2+ sensor based on laser scanned silicon transducer (LSST) for multicomponent analysis
JF  - Talanta. 59 (2003), H. 4
Y1  - 2003
SN  - 0039-9140
SP  - 785
EP  - 795
ER  - 
TY  - JOUR
A1  - Ermelenko, Y.
A1  - Yoshinobu, T.
A1  - Mourzina, Y.
A1  - Schöning, Michael Josef
A1  - Vlasov, Y.
A1  - Iwasaki, H.
T1  - The hybrid K+/Ca2+ sensor based on laser scanned silicon transducer for multi-component analysis
JF  - Proceedings of ICAS 2001, IUPAC [3rd] International Congress on Analytical Sciences 2001 : August 6 - 10, 2001, Waseda University, Tokyo
Y1  - 2002
N1  - International Congress on Analytical Sciences <2001, Tokyo> ; International Union of Pure and Applied Chemistry. Pure and applied chemistry ; 73,10. ; Analytical sciences ; 17.2001, special issue
SP  - i777
EP  - i780
PB  - Japan Society for Analytical Chemistry
CY  - Tokyo
ER  - 
TY  - CHAP
A1  - Ermelenko, Y.
A1  - Yoshinobu, T.
A1  - Mourzina, Y.
A1  - Schöning, Michael Josef
A1  - Vlasov, Y.
A1  - Iwasaki, H.
T1  - A multisensor based on laser scanned silicon transducer (LSST): development and properties
T2  - Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimarães, Portugal, September 21 - 24, 2003
Y1  - 2003
SP  - 72
EP  - 73
ER  - 
TY  - JOUR
A1  - Ermolaev, A.P.
A1  - Nivokov, I.A.
A1  - Melnikova, L.I.
A1  - Kotliar, Konstantin
T1  - Сравнительная характеристика химического состава витреального содержимого кадаверных глаз и глаз с рефрактерной терминальной глаукомой
T1  - Comparative characteristics of the chemical composition of vitreal contents of cadaver eyes and eyes with terminal refractory glaucoma
JF  - Vestnik oftalmologii
N2  - Purpose — to compare the chemical elemental composition of vitreous cavity content taken from cadaveric eyes compared to samples taken from the eyes with terminal stage refractory glaucoma with decompensated intraocular pressure (IOP). Material and methods. The vitreous contents of the eyes from 2 groups were studied. The 1st group included 15 cadaveric eyes; the 2nd group included 15 eyes with refractory glaucoma in the terminal stage of the disease with decompensated IOP in patients with hypertension pain. The vitreal content samples were taken in the course of antiglaucoma surgery aimed at preserving the eye as an organ and involving employment of drainage in the vitreous cavity. The study of virtual contents was carried out on energy dispersive spectrometer Oxford X-Max 50 integrated into scanning electron microscope Zeiss EVO LS10. Results. Increased concentrations of Kalium and Phosphorus were detected in the vitreous content of cadaveric eyes compared with the vitreal content from the eyes with terminal glaucoma with decompensated IOP taken in vivo (K — 0.172/0.093; P — 0.045/0.025 mmol/L). In the vitreous cavity in the eyes with end-stage glaucoma with decompensated IOP, the concentration of Nitrogen was higher in comparison with human cadaver eyes (2.030/1.424 mmol/L). Conclusion. The increased concentrations of Kalium and Phosphorus in the vitreous content of cadaveric eyes is associated with postmortem autolytic processes and with the release of intracellular content in the destruction of cell membranes. The increased Nitrogen concentration in the vitreal contents of the eyes with terminal stage glaucoma with decompensated IOP may be associated with the presence of osmotically active nitrogen-containing compounds in the eyes with increased IOP.
Y1  - 2018
U6  - http://dx.doi.org/10.17116/oftalma2018134051195
VL  - 5
IS  - 2
SP  - 195
EP  - 201
PB  - Media Sfera
CY  - Moskau
ER  - 
TY  - JOUR
A1  - Ermolaev, AP
A1  - Erichev, VP
A1  - Antonov, AA
A1  - Grigoryan, GL
A1  - Kotliar, Konstantin
A1  - Levitsky, YV
A1  - Hderi, K
A1  - Mazurova, YV
T1  - Assessing retinal photosensitivity in patients with central vision impairment using a portable perimeter (a preliminary report)
JF  - Vestnik oftalmologii
Y1  - 2019
U6  - http://dx.doi.org/10.17116/oftalma201913503146
N1  - Abstract in Englisch
VL  - 135
IS  - 3
SP  - 46
EP  - 54
ER  - 
TY  - JOUR
A1  - Ermolenko, Y. E.
A1  - Yoshinobu, T.
A1  - Mourzina, Y. G.
A1  - Vlasov, Y. G.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Laserscanned transducer (LSST) as a multisensor system
JF  - Sensors and Actuators B. 103 (2004), H. 1-2
Y1  - 2004
SN  - 0925-4005
SP  - 457
EP  - 462
ER  - 
TY  - JOUR
A1  - Ermolenko, Y.E.
A1  - Vlasov, Y.G.
A1  - Kolodnikov, V.V.
A1  - Shabaldkin, D. A.
A1  - Kloock, Joachim P.
A1  - Schöning, Michael Josef
T1  - Diffusion of radioactive tracers (204Tl, 110mAg) and ionic conductivity in membrane materials for the chemical sensors
JF  - Advances in nuclear and radiochemistry : extended abstracts of papers presented at the Sixth International Conference on Nuclear and Radiochemistry (NRC-6), 29 August to 3 September 2004, Aachen, Germany ; in cooperation with University of Cologne, GDCh, FECS, OECD-NEA and IAEA / Syed M. Qaim ... (eds.).
Y1  - 2004
SN  - 3893363629
N1  - Schriften des Forschungszentrums Jülich Reihe Allgemeines und Interdisziplinäres ; 3. International Conference on Nuclear and Radiochemistry ; (6, 2004, Aachen)
SP  - 483
EP  - 485
PB  - Forschungszentrum Jülich, Zentralbibliothek
CY  - Jülich
ER  - 
TY  - CHAP
A1  - Eschler, Eric
A1  - Wozniak, Felix
A1  - Richter, Christoph
A1  - Drechsler, Klaus
T1  - Materialanalyse an lokal verstärkten Triaxialgeflechten
T2  - Leichtbau in Forschung und industrieller Anwendung von der Nano- bis zur Makroebene, LLC, Landshuter Leichtbau-Colloquium, 9
Y1  - 2019
SN  - 978-3-9818439-2-7
SP  - 120
EP  - 131
PB  - Leichtbau Cluster
CY  - Landshut
ER  - 
TY  - JOUR
A1  - Eschweiler, J.
A1  - Laack, Walter van
A1  - Staat, Manfred
T1  - Elektromyographische Untersuchungen zur Kräftigung der Oberschenkelmuskulatur mit einem myoelektrischen Stimulator nach arthroskopischen Eingriffen am Kniegelenk
JF  - Orthopädische Praxis. 43 (2007), H. 10
Y1  - 2007
SN  - 0030-588x
SP  - 539
EP  - 542
ER  - 
TY  - JOUR
A1  - Faßbender, F.
A1  - Schmitt, G.
A1  - Schöning, Michael Josef
A1  - Lüth, H.
A1  - Buß, G.
A1  - Schultze, J. W.
T1  - Optimization of passivation layers for corrosion protection of silicon-based microelectrode arrays
JF  - Sensors and Actuators B. 68 (2000), H. 1-3
Y1  - 2000
SN  - 0925-4005
SP  - 128
EP  - 133
ER  - 
TY  - JOUR
A1  - Faßbender, F.
A1  - Schmitt, G.
A1  - Schöning, Michael Josef
A1  - Lüth, H.
A1  - Buß, G.
A1  - Schultze, J. W.
T1  - Passivation and corrosion of microsensor devices exemplified at microelectrode arrays
JF  - Proceedings : The Hague, The Netherlands, September 12 - 15, 1999 / [ed. by M. Bartek]. Vol 1.
Y1  - 1999
SN  - 90-76699-02-X
N1  - Eurosensors ; (13, 1999, 's-Gravenhage) ; Eurosensors ; (13 : ; 1999.09.12-15 : ; The Hague) ; European Conference on Solid-State Transducers ; (13 : ; 1999.09.12-15 : ; The Hague)
SP  - 953
EP  - 956
CY  - The Hague, The Netherlands
ER  - 
TY  - JOUR
A1  - Feucht, Nikolaus
A1  - Schönbach, Etienne Michael
A1  - Lanzl, Ines
A1  - Kotliar, Konstantin
A1  - Lohmann, Chris Patrick
A1  - Maier, Mathias
T1  - Changes in the foveal microstructure after intravitreal bevacizumab application in patients with retinal vascular disease
JF  - Clinical Ophthalmology
Y1  - 2013
SN  - 1177-5483
VL  - 7
SP  - 173
EP  - 178
PB  - Dove Medical Press
CY  - Auckland, New Zealand
ER  - 
TY  - JOUR
A1  - Figueroa-Miranda, Gabriela
A1  - Feng, Lingyan
A1  - Shiu, Simon Chi-Chin
A1  - Dirkzwager, Roderick Marshall
A1  - Cheung, Yee-Wai
A1  - Tanner, Julian Alexander
A1  - Schöning, Michael Josef
A1  - Offenhäusser, Andreas
A1  - Mayer, Dirk
T1  - Aptamer-based electrochemical biosensor for highly sensitive and selective malaria detection with adjustable dynamic response range and reusability
JF  - Sensor and Actuators B: Chemical
N2  - Malaria infection remains a significant risk for much of the population of tropical and subtropical areas, particularly in developing countries. Therefore, it is of high importance to develop sensitive, accurate and inexpensive malaria diagnosis tests. Here, we present a novel aptamer-based electrochemical biosensor (aptasensor) for malaria detection by impedance spectroscopy, through the specific recognition between a highly discriminatory DNA aptamer and its target Plasmodium falciparum lactate dehydrogenase (PfLDH). Interestingly, due to the isoelectric point (pI) of PfLDH, the aptasensor response showed an adjustable detection range based on the different protein net-charge at variable pH environments. The specific aptamer recognition allows sensitive protein detection with an expanded detection range and a low detection limit, as well as a high specificity for PfLDH compared to analogous proteins. The specific feasibility of the aptasensor is further demonstrated by detection of the target PfLDH in human serum. Furthermore, the aptasensor can be easily regenerated and thus applied for multiple usages. The robustness, sensitivity, and reusability of the presented aptasensor make it a promising candidate for point-of-care diagnostic systems.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.snb.2017.07.117
SN  - 0925-4005
VL  - 255
IS  - P1
SP  - 235
EP  - 243
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Fink, G. R.
A1  - Marshall, J. C.
A1  - Shah, N. J.
A1  - Weiss, P.H.
A1  - Halligan, P. W.
A1  - Grosse-Ruyken, M.
A1  - Ziemons, Karl
A1  - Zilles, K.
A1  - Freund, H. J.
T1  - Line bisection judgments implicate right parietal cortex and cerebellum as assessed by fMRI
JF  - Neurology
Y1  - 2000
SN  - 1526-632X
VL  - 54
IS  - 6
SP  - 1324
EP  - 1331
ER  - 
TY  - JOUR
A1  - Fischer, Felix
A1  - Selver, M. Alper
A1  - Gezer, Sinem
A1  - Dicle, Oguz
A1  - Hillen, Walter
T1  - Systematic Parameterization, Storage, and Representation of Volumetric DICOM Data
JF  - Journal of Medical and Biological Engineering
Y1  - 2015
U6  - http://dx.doi.org/10.1007/s40846-015-0097-5
SN  - 2199-4757
VL  - 35
IS  - 6
SP  - 709
EP  - 723
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Forst, Thomas
A1  - Karagiannis, E.
A1  - Lübben, G.
A1  - Hohberg, C.
A1  - Schöndorf, T.
A1  - Dikta, Gerhard
A1  - Drexler, M.
A1  - Morcos, M.
A1  - Dänschel, W.
A1  - Borchert, M.
A1  - Pfützner, A.
T1  - Pleiotrophic and anti-inflammatory effects of pioglitazone precede the metabolic activity in type 2 diabetic patients with coronary artery disease
JF  - Atherosclerosis. 197 (2008), H. 1
Y1  - 2008
U6  - http://dx.doi.org/10.1016/j.atherosclerosis.2007.05.006
SN  - 0021-9150
SP  - 311
EP  - 317
ER  - 
TY  - JOUR
A1  - Frank, T.
A1  - Buchwald, D.
A1  - Pennekamp, W.
A1  - Reber, D.
A1  - Sponagel, Stefan
A1  - Laszkovics, A.
A1  - Weber, Hans-Joachim
T1  - Röntgenologische Untersuchung der Strömungseigenschaften funktioneller Komponenten der Herz-Lungen-Maschine
JF  - Kardiotechnik. 18 (2009), H. 2
Y1  - 2009
SN  - 0941-2670
N1  - gedruckt in der Bibliothek unter der Signatur 63 Z 629
SP  - 31
EP  - 35
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Duong, Minh Tuan
A1  - Staat, Manfred
T1  - Simulating beating cardiomyocytes with electromechanical coupling
T2  - II. International Conference on Biomedical Technology : 28-30 October 2015 Hannover, Germany / T. Lenarz, P. Wriggers (Eds.)
Y1  - 2015
SP  - 1
EP  - 2
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Goßmann, Matthias
A1  - Raatschen, Hans-Jürgen
A1  - Temiz Artmann, Aysegül
A1  - Staat, Manfred
T1  - Simulation of cardiac cell-seeded membranes using the edge-based smoothed FEM
T2  - Shell and membrane theories in mechanics and biology. (Advanced structured materials ; 45)
N2  - We present an electromechanically coupled Finite Element model for cardiac tissue. It bases on the mechanical model for cardiac tissue of Hunter et al. that we couple to the McAllister-Noble-Tsien electrophysiological model of purkinje fibre cells. The corresponding system of ordinary differential equations is implemented on the level of the constitutive equations in a geometrically and physically nonlinear version of the so-called edge-based smoothed FEM for plates. Mechanical material parameters are determined from our own pressure-deflection experimental setup. The main purpose of the model is to further examine the experimental results not only on mechanical but also on electrophysiological level down to ion channel gates. Moreover, we present first drug treatment simulations and validate the model with respect to the experiments.
Y1  - 2015
SN  - 978-3-319-02534-6 ; 978-3-319-02535-3
SP  - 187
EP  - 212
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Goßmann, Matthias
A1  - Temiz Artmann, Aysegül
A1  - Staat, Manfred
T1  - Simulation of cardiac cell-seeded membranes using the edge-based smoothed FEM
T2  - 1st International Conference "Shell and Membrane Theories in Mechanics and Biology: From Macro- to Nanoscale Structures", Minsk, Belarus, Sept. 16-20, 2013
Y1  - 2013
SN  - 978-985-553-135-8
SP  - 165
EP  - 167
PB  - Verl. d. Weißruss. Staatl. Univ.
CY  - Minsk
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Koch, Jan-Peter
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
ED  - Onate, E.
T1  - Evaluation of a computational model for drug action on cardiac tissue
T2  - 11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20 - 25, 2014, Barcelona
Y1  - 2014
SP  - 1
EP  - 12
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  - 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  - CHAP
A1  - Frotscher, Ralf
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
ED  - Eberhardsteiner, J.
T1  - Application of an edge-based smoothed finite element method on geometrically non-linear plates of non-linear material
T2  - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)
Y1  - 2012
N1  - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
ED  - Holzapfel, Gerhard A.
T1  - Effectiveness of the edge-based smoothed finite element method applied to soft biological tissues
T2  - ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012
Y1  - 2012
SN  - 978-3-85125-223-1
PB  - Verlag d. Technischen Universität Graz
CY  - Graz
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  - CHAP
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - An electromechanical model for cardiac tissue constructs
T2  - Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen, 20.07.2015 - 23.07.2015  / ed.: Stefanie Elgeti ; Jaan-Willem Simon
Y1  - 2015
SP  - 1
EP  - 4
PB  - RWTH Aachen University
CY  - Aachen
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Staat, Manfred
ED  - Nithiarasu, Perumal
T1  - Homogenization of a cardiac tissue construct
T2  - CMBE15 : 4th International Conference on Computational & Mathematical Biomedical Engineering ; 29th June - 1st July 2015 ; École Normale Supérieure de Cachan ; Cachan (Paris), France
Y1  - 2015
SN  - 2227-9385
N1  - Konferenzband unter:
http://www.compbiomed.net/getfile.php?type=12/site_documents&id=Proceedings_2227-9385_compressed.pdf
SP  - 645
EP  - 648
PB  - CMBE
CY  - [s.l.]
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Staat, Manfred
ED  - Artmann, Gerhard
ED  - Temiz Artmann, Aysegül
ED  - Zhubanova, Azhar A.
ED  - Digel, Ilya
T1  - Towards Patient-Specific Computational Modeling of hiPS-Derived Cardiomyocyte Function and Drug Action
T2  - Biological, Physical and Technical Basics of Cell Engineering
N2  - Human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) today are widely used for the investigation of normal electromechanical cardiac function, of cardiac medication and of mutations. Computational models are thus established that simulate the behavior of this kind of cells. This section first motivates the modeling of hiPS-CM and then presents and discusses several modeling approaches of microscopic and macroscopic constituents of human-induced pluripotent stem cell-derived and mature human cardiac tissue. The focus is led on the mapping of the computational results one can achieve with these models onto mature human cardiomyocyte models, the latter being the real matter of interest. Model adaptivity is the key feature that is discussed because it opens the way for modeling various biological effects like biological variability, medication, mutation and phenotypical expression. We compare the computational with experimental results with respect to normal cardiac function and with respect to inotropic and chronotropic drug effects. The section closes with a discussion on the status quo of the specificity of computational models and on what challenges have to be solved to reach patient-specificity.
Y1  - 2018
SN  - 978-981-10-7904-7
U6  - http://dx.doi.org/10.1007/978-981-10-7904-7_10
SP  - 233
EP  - 250
PB  - Springer
CY  - Singapore
ER  - 
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  - Furuichi, K.
A1  - Yoshinobu, T.
A1  - Ermelenko, T.
A1  - Mourzina, Y.
A1  - Iwasaki, H.
A1  - Schöning, Michael Josef
T1  - Simultaneous visualization of multiple ions by the chemical imaging sensor
JF  - Proceedings of the 5th East Asian Conference on Chemical Sensors; the 33rd Chemical Sensor Symposium : December 4 - 7, 2001, Huis Ten Bosch, Sasebo-shi, Nagasaki, Japan / Japan Association of Chemical Sensors; the Electrochemical Society of Japan
Y1  - 2001
N1  - Chemical sensors; 17.2001 Suppl. B; East Asian Conference on Chemical Sensors ; (5, 2001; Nagasaki)
SP  - 399
EP  - 401
PB  - Japan Association of Chemical Sensors
CY  - Kasuga, Fukuoka-ken
ER  - 
TY  - THES
A1  - Föckler, Nicole
T1  - Biomarker zur Prognose von Frühgeburten : ein biomedizintechnischer Ansatz
Y1  - 2016
U6  - http://dx.doi.org/10.4126/FRL01-006401575
N1  - Dissertation, Köln, Universität zu Köln, 2016
PB  - Deutsche Zentralbibliothek für Medizin
CY  - Köln
ER  - 
TY  - CHAP
A1  - Förster, Arnold
A1  - Stock, Jürgen
A1  - Montanari, Simone
A1  - Lepsa, Mihail Ion
A1  - Lüth, Hans
T1  - Fabrication and characterisation of GaAs Gunn Diode Chips for applications at 77 GHz in automotive industry
N2  - GaAs-based Gunn diodes with graded AlGaAs hot electron injector heterostructures have been developed under the special needs in automotive applications. The fabrication of the Gunn diode chips was based on total substrate removal and processing of integrated Au heat sinks. Especially, the thermal and RF behavior of the diodes have been analyzed by DC, impedance and S-parameter measurements. The electrical investigations have revealed the functionality of the hot electron injector. An optimized layer structure could fulfill the requirements in adaptive cruise control (ACC) systems at 77 GHz with typical output power between 50 and 90 mW.
KW  - Biosensor
KW  - Gunn diode
KW  - microwave generation
KW  - GaAs hot electron injector
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1462
ER  - 
TY  - JOUR
A1  - Gaigall, Daniel
ED  - AitSahlia, Farid
T1  - Allocating and forecasting changes in risk
JF  - Journal of risk
N2  - We consider time-dependent portfolios and discuss the allocation of changes in the risk of a portfolio to changes in the portfolio’s components. For this purpose we adopt established allocation principles. We also use our approach to obtain forecasts for changes in the risk of the portfolio’s components. To put the approach into practice we present an implementation based on the output of a simulation. Allocation is illustrated with an example portfolio in the context of Solvency II. The quality of the forecasts is investigated with an empirical study.
KW  - portfolio risk
KW  - allocation
KW  - forecast
KW  - covariance principle
KW  - conditional expectation principle
Y1  - 2023
U6  - http://dx.doi.org/10.21314/JOR.2022.048
SN  - 1755-2842
SN  - 1465-1211
VL  - 25
IS  - 3
SP  - 1
EP  - 24
PB  - Infopro Digital Risk
CY  - London
ER  - 
TY  - JOUR
A1  - Gaigall, Daniel
T1  - On the applicability of several tests to models with not identically distributed random effects
JF  - Statistics : A Journal of Theoretical and Applied Statistics
N2  - We consider Kolmogorov–Smirnov and Cramér–von-Mises type tests for testing central symmetry, exchangeability, and independence. In the standard case, the tests are intended for the application to independent and identically distributed data with unknown distribution. The tests are available for multivariate data and bootstrap procedures are suitable to obtain critical values. We discuss the applicability of the tests to random effects models, where the random effects are independent but not necessarily identically distributed and with possibly unknown distributions. Theoretical results show the adequacy of the tests in this situation. The quality of the tests in models with random effects is investigated by simulations. Empirical results obtained confirm the theoretical findings. A real data example illustrates the application.
KW  - central symmetry test
KW  - exchangeability test
KW  - independence test
KW  - random effects
KW  - not identically distributed
Y1  - 2023
SN  - 0323-3944
U6  - http://dx.doi.org/10.1080/02331888.2023.2193748
SN  - 1029-4910
VL  - 57
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - CHAP
A1  - Gaigall, Daniel
T1  - On Consistent Hypothesis Testing In General Hilbert Spaces
N2  - Inference on the basis of high-dimensional and functional data are two topics which are discussed frequently in the current statistical literature. A possibility to include both topics in a single approach is working on a very general space for the underlying observations, such as a separable Hilbert space. We propose a general method for consistently hypothesis testing on the basis of random variables with values in separable Hilbert spaces. We avoid concerns with the curse of dimensionality due to a projection idea. We apply well-known test statistics from nonparametric inference to the projected data and integrate over all projections from a specific set and with respect to suitable probability measures. In contrast to classical methods, which are applicable for real-valued random variables or random vectors of dimensions lower than the sample size, the tests can be applied to random vectors of dimensions larger than the sample size or even to functional and high-dimensional data. In general, resampling procedures such as bootstrap or permutation are suitable to determine critical values. The idea can be extended to the case of incomplete observations. Moreover, we develop an efficient algorithm for implementing the method. Examples are given for testing goodness-of-fit in a one-sample situation in [1] or for testing marginal homogeneity on the basis of a paired sample in [2]. Here, the test statistics in use can be seen as generalizations of the well-known Cramérvon-Mises test statistics in the one-sample and two-samples case. The treatment of other testing problems is possible as well. By using the theory of U-statistics, for instance, asymptotic null distributions of the test statistics are obtained as the sample size tends to infinity. Standard continuity assumptions ensure the asymptotic exactness of the tests under the null hypothesis and that the tests detect any alternative in the limit. Simulation studies demonstrate size and power of the tests in the finite sample case, confirm the theoretical findings, and are used for the comparison with concurring procedures. A possible application of the general approach is inference for stock market returns, also in high data frequencies. In the field of empirical finance, statistical inference of stock market prices usually takes place on the basis of related log-returns as data. In the classical models for stock prices, i.e., the exponential Lévy model, Black-Scholes model, and Merton model, properties such as independence and stationarity of the increments ensure an independent and identically structure of the data. Specific trends during certain periods of the stock price processes can cause complications in this regard. In fact, our approach can compensate those effects by the treatment of the log-returns as random vectors or even as functional data.
Y1  - 2022
U6  - http://dx.doi.org/10.11159/icsta22.157
N1  - Proceedings of the 4th International Conference on Statistics: Theory and Applications (ICSTA’22) Prague, Czech Republic – July 28- 30
SP  - Paper No. 157
PB  - Avestia Publishing
CY  - Orléans, Kanada
ER  - 
TY  - THES
A1  - Gaigall, Daniel
T1  - Vergleich von statistischen Tests im verbundenen und unabhängigen Stichprobenfall
N2  - Es werden Effizienzbegriffe zum Vergleich von statistischen Tests basierend auf verschiedenen statistischen Experimenten eingeführt. Dabei handelt es sich um die schon aus dem Vergleich von statistischen Tests in je demselben Modell bekannten asymptotischen relativen Effizienzen wie die Hodges-Lehmann-Effizienz, die Bahadur-Effizienz und die Pitman-Effizienz sowie um Kriterien basierend auf Volumina von Konfidenzbereichen. Effizienzaussagen werden unter anderem für Likelihood-Quotienten-Tests und Waldsche Tests im Rahmen eines allgemeinen multivariaten parametrischen Modells erhalten. Statistische Tests zur Prüfung von Hypothesen über die relative Wirksamkeit zweier Experimente werden vorgeschlagen. Auf der Grundlage der erhaltenen Ergebnisse erfolgt ein Vergleich der Wirksamkeit von korrespondierenden Verfahren bei verbundener Stichprobenerhebung und unabhängiger Stichprobenerhebung. Die Rolle der Kovarianzmatrix bei verbundener Stichprobenerhebung wird insbesondere unter der Annahme, dass die zugrunde liegenden Verteilungen durch k-parametrische Exponentialfamilien modellierbar sind, herausgearbeitet. Verbindungen zu Effizienzbegriffen bei Punkt- und Konfidenzbereichsschätzverfahren werden aufgezeigt. Ausführlichere Untersuchungen betreffen die korrespondierenden Hotellingschen T²-Tests im multivariaten Normalverteilungsfall, die klassischen Homogenitatstests bei k × k-Kontingenztafeln und die Wilcoxon Tests in nichtparametrischen Lagealternativmodellen
KW  - Vergleich von Experimenten
KW  - Hypothesentests
KW  - Effizienz
KW  - testing hypotheses
KW  - efficiency
Y1  - 2016
U6  - http://dx.doi.org/10.15488/8678
N1  - Dissertation, Gottfried Wilhelm Leibniz Universität Hannover, 2016
PB  - Gottfried Wilhelm Leibniz Universität Hannover
CY  - Hannover
ER  - 
TY  - JOUR
A1  - Gaigall, Daniel
T1  - Test for Changes in the Modeled Solvency Capital Requirement of an Internal Risk Model
JF  - ASTIN Bulletin
N2  - In the context of the Solvency II directive, the operation of an internal risk model is a possible way for risk assessment and for the determination of the solvency capital requirement of an insurance company in the European Union. A Monte Carlo procedure is customary to generate a model output. To be compliant with the directive, validation of the internal risk model is conducted on the basis of the model output. For this purpose, we suggest a new test for checking whether there is a significant change in the modeled solvency capital requirement. Asymptotic properties of the test statistic are investigated and a bootstrap approximation is justified. A simulation study investigates the performance of the test in the finite sample case and confirms the theoretical results. The internal risk model and the application of the test is illustrated in a simplified example. The method has more general usage for inference of a broad class of law-invariant and coherent risk measures on the basis of a paired sample.
KW  - Bootstrap
KW  - Empirical process
KW  - Functional Delta Method
KW  - Hadamard differentiability
KW  - Paired sample
Y1  - 2021
U6  - http://dx.doi.org/10.1017/asb.2021.20
SN  - 1783-1350
VL  - 51
IS  - 3
SP  - 813
EP  - 837
PB  - Cambridge Univ. Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Gaigall, Daniel
T1  - Hoeffding-Blum-Kiefer-Rosenblatt independence test statistic on partly not identically distributed data
JF  - Communications in Statistics - Theory and Methods
N2  - The established Hoeffding-Blum-Kiefer-Rosenblatt independence test statistic is investigated for partly not identically distributed data. Surprisingly, it turns out that the statistic has the well-known distribution-free limiting null distribution of the classical criterion under standard regularity conditions. An application is testing goodness-of-fit for the regression function in a non parametric random effects meta-regression model, where the consistency is obtained as well. Simulations investigate size and power of the approach for small and moderate sample sizes. A real data example based on clinical trials illustrates how the test can be used in applications.
KW  - Brownian Pillow
KW  - Hoeffding-Blum-Kiefer-Rosenblatt independence test
KW  - not identically distributed
KW  - random effects meta-regression model
Y1  - 2020
U6  - http://dx.doi.org/10.1080/03610926.2020.1805767
SN  - 1532-415X
VL  - 51
IS  - 12
SP  - 4006
EP  - 4028
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Gaigall, Daniel
T1  - Testing marginal homogeneity of a continuous bivariate distribution with possibly incomplete paired data
JF  - Metrika
N2  - We discuss the testing problem of homogeneity of the marginal distributions of a continuous bivariate distribution based on a paired sample with possibly missing components (missing completely at random). Applying the well-known two-sample Crámer–von-Mises distance to the remaining data, we determine the limiting null distribution of our test statistic in this situation. It is seen that a new resampling approach is appropriate for the approximation of the unknown null distribution. We prove that the resulting test asymptotically reaches the significance level and is consistent. Properties of the test under local alternatives are pointed out as well. Simulations investigate the quality of the approximation and the power of the new approach in the finite sample case. As an illustration we apply the test to real data sets.
KW  - Marginal homogeneity test
KW  - Crámer–von-Mises distance
KW  - Paired sample
KW  - Incomplete data
KW  - Resampling test
Y1  - 2019
U6  - http://dx.doi.org/10.1007/s00184-019-00742-5
SN  - 1435-926X
VL  - 2020
IS  - 83
SP  - 437
EP  - 465
PB  - Springer
ER  - 
TY  - JOUR
A1  - Gaigall, Daniel
T1  - Rothman–Woodroofe symmetry test statistic revisited
JF  - Computational Statistics & Data Analysis
N2  - The Rothman–Woodroofe symmetry test statistic is revisited on the basis of independent but not necessarily identically distributed random variables. The distribution-freeness if the underlying distributions are all symmetric and continuous is obtained. The results are applied for testing symmetry in a meta-analysis random effects model. The consistency of the procedure is discussed in this situation as well. A comparison with an alternative proposal from the literature is conducted via simulations. Real data are analyzed to demonstrate how the new approach works in practice.
Y1  - 2020
U6  - http://dx.doi.org/10.1016/j.csda.2019.106837
SN  - 0167-9473
VL  - 2020
IS  - 142
SP  - Artikel 106837
PB  - Elsevier
CY  - Amsterdam
ER  -