TY  - JOUR
A1  - Bhattarai, Aroj
A1  - Horbach, Andreas
A1  - Staat, Manfred
A1  - Kowalczyk, Wojciech
A1  - Tran, Thanh Ngoc
T1  - Virgin passive colon biomechanics and a literature review of active contraction constitutive models
JF  - Biomechanics
N2  - The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel–Gasser–Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill’s three-element model, Murphy’s four-state cross-bridge chemical kinetic model and Huxley’s sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.
KW  - virgin passive
KW  - strain energy function
KW  - smooth muscle contraction
KW  - viscoelasticity
KW  - damage
Y1  - 2022
U6  - https://doi.org/10.3390/biomechanics2020013
SN  - 2673-7078
VL  - 2
IS  - 2
SP  - 138
EP  - 157
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Bhattarai, Aroj
A1  - Frotscher, Ralf
A1  - Staat, Manfred
ED  - Natal Jorge, Renato
T1  - Significance of fibre geometry on passive-active response of pelvic muscles to evaluate pelvic dysfunction
T2  - BioMedWomen: Proceedings of the international conference on clinical and bioengineering for women's health
Y1  - 2016
SN  - 978-1-138-02910-1
SP  - 185
EP  - 188
PB  - CRC Press
CY  - Boca Raton
ER  - 
TY  - CHAP
A1  - Bhattarai, Aroj
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - Biomechanical study of the female pelvic floor dysfunction using the finite element method
T2  - Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 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  - 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  - https://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  - THES
A1  - Bhattarai, Aroj
T1  - Constitutive modeling of female pelvic floor dysfunctions and reconstructive surgeries using prosthetic mesh implants
Y1  - 2018
SN  - 978-3-9818074-8-6
U6  - https://doi.org/10.17185/duepublico/70340
N1  - Duisburg-Essen, Univ., Diss., 2018
ER  - 
TY  - JOUR
A1  - Bertz, Morten
A1  - Schöning, Michael Josef
A1  - Molinnus, Denise
A1  - Homma, Takayuki
T1  - Influence of temperature, light, and H₂O₂ concentration on microbial spore inactivation: in-situ Raman spectroscopy combined with optical trapping
JF  - Physica status solidi (a) applications and materials science
N2  - To gain insight on chemical sterilization processes, the influence of temperature (up to 70 °C), intense green light, and hydrogen peroxide (H₂O₂) concentration (up to 30% in aqueous solution) on microbial spore inactivation is evaluated by in-situ Raman spectroscopy with an optical trap. Bacillus atrophaeus is utilized as a model organism. Individual spores are isolated and their chemical makeup is monitored under dynamically changing conditions (temperature, light, and H₂O₂ concentration) to mimic industrially relevant process parameters for sterilization in the field of aseptic food processing. While isolated spores in water are highly stable, even at elevated temperatures of 70 °C, exposure to H₂O₂ leads to a loss of spore integrity characterized by the release of the key spore biomarker dipicolinic acid (DPA) in a concentration-dependent manner, which indicates damage to the inner membrane of the spore. Intensive light or heat, both of which accelerate the decomposition of H₂O₂ into reactive oxygen species (ROS), drastically shorten the spore lifetime, suggesting the formation of ROS as a rate-limiting step during sterilization. It is concluded that Raman spectroscopy can deliver mechanistic insight into the mode of action of H₂O₂-based sterilization and reveal the individual contributions of different sterilization methods acting in tandem.
KW  - hydrogen peroxide
KW  - optical spore trapping
KW  - Raman spectroscopy
KW  - sterilization conditions
KW  - temperature
Y1  - 2024
U6  - https://doi.org/10.1002/pssa.202300866
SN  - 1862-6319 (Online)
SN  - 1862-6300 (Print)
N1  - Corresponding author: Michael J. Schöning
IS  - Early View
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Bertz, Morten
A1  - Molinnus, Denise
A1  - Schöning, Michael Josef
A1  - Homma, Takayuki
T1  - Real-time monitoring of H₂O₂ sterilization on individual bacillus atrophaeus spores by optical sensing with trapping Raman spectroscopy
JF  - Chemosensors
N2  - Hydrogen peroxide (H₂O₂), a strong oxidizer, is a commonly used sterilization agent employed during aseptic food processing and medical applications. To assess the sterilization efficiency with H₂O₂, bacterial spores are common microbial systems due to their remarkable robustness against a wide variety of decontamination strategies. Despite their widespread use, there is, however, only little information about the detailed time-resolved mechanism underlying the oxidative spore death by H₂O₂. In this work, we investigate chemical and morphological changes of individual Bacillus atrophaeus spores undergoing oxidative damage using optical sensing with trapping Raman microscopy in real-time. The time-resolved experiments reveal that spore death involves two distinct phases: (i) an initial phase dominated by the fast release of dipicolinic acid (DPA), a major spore biomarker, which indicates the rupture of the spore’s core; and (ii) the oxidation of the remaining spore material resulting in the subsequent fragmentation of the spores’ coat. Simultaneous observation of the spore morphology by optical microscopy corroborates these mechanisms. The dependence of the onset of DPA release and the time constant of spore fragmentation on H₂O₂ shows that the formation of reactive oxygen species from H₂O₂ is the rate-limiting factor of oxidative spore death.
KW  - DPA (dipicolinic acid)
KW  - sterilization
KW  - Bacillus atrophaeus spores
KW  - optical trapping
KW  - Raman spectroscopy
KW  - optical sensor setup
Y1  - 2023
U6  - https://doi.org/10.3390/chemosensors11080445
SN  - 2227-9040
N1  - This article belongs to the Special Issue "Biosensors and Chemical Sensors for Food and Healthcare Monitoring—Celebrating the 10th Anniversary"
VL  - 8
IS  - 11
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Berretz, Frank
A1  - Skorupa, Sasche
A1  - Sander, Volker
A1  - Belloum, Adam
A1  - Bubak, Marian
T1  - Actor-Driven Workflow Execution in Distributed Environments
JF  - Euro-Par 2010 Parallel Processing Workshops : HeteroPAR, HPCC, HiBB, CoreGrid, UCHPC, HPCF, PROPER, CCPI, VHPC ; Ischia, Italy, August 31 - September 3, 2010 ; revised selected papers / Mario R. Guarracino ... (eds.)
Y1  - 2011
SN  - 978-3-642-21877-4
N1  - Lecture Notes in Computer Science ; 6586
SP  - 287
EP  - 294
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Berretz, F.
A1  - Skorupa, S.
A1  - Sander, Volker
A1  - Belloum, A.
T1  - Towards an actor-driven workflow management system for grids
JF  - International Symposium on Collaborative Technologies and Systems (CTS), 2010 : 17 - 21 May 2010, Chicago, Illinois, USA / IEEE
Y1  - 2010
SN  - 978-1-4244-6619-1
SP  - 611
EP  - 616
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Bergmann, Sandra
A1  - Demuth, Bastian
A1  - Sander, Volker
T1  - A Web Framework for Workflow Submission and Monitoring via UNICORE 6 based on Distributable Scientific Workflow Templates
JF  - UNICORE Summit 2011 : proceedings, 7-8 July 2011, Torun, Poland / Mathilde Romberg ... (Eds.)
Y1  - 2011
SN  - 9783893367504
N1  - UNICORE Summit ; (2011 ; 2011.07.07-08 ; Torun) ; Schriften des Forschungszentrums Jülich IAS Series 9
SP  - 45
EP  - 50
PB  - Forschungszentrum Jülich
CY  - Jülich
ER  - 
TY  - JOUR
A1  - Berghoff, G.
A1  - Lanske, D.
A1  - Schultze, K.
A1  - Ziemons, Karl
T1  - Jets and QCD-effects in muon-nuclean scattering
JF  - Verhandlungen der Deutschen Physikalischen Gesellschaft
Y1  - 1988
SN  - 0420-0195
VL  - 23
IS  - 5
ER  - 
TY  - JOUR
A1  - Belavy, Daniel L.
A1  - Albracht, Kirsten
A1  - Bruggemann, Gert-Peter
A1  - Vergroesen, Pieter-Paul A.
A1  - Dieen, Jaap H. van
T1  - Can exercise positively influence the intervertebral disc?
JF  - Sports Medicine
N2  - To better understand what kinds of sports and exercise could be beneficial for the intervertebral disc (IVD), we performed a review to synthesise the literature on IVD adaptation with loading and exercise. The state of the literature did not permit a systematic review; therefore, we performed a narrative review. The majority of the available data come from cell or whole-disc loading models and animal exercise models. However, some studies have examined the impact of specific sports on IVD degeneration in humans and acute exercise on disc size. Based on the data available in the literature, loading types that are likely beneficial to the IVD are dynamic, axial, at slow to moderate movement speeds, and of a magnitude experienced in walking and jogging. Static loading, torsional loading, flexion with compression, rapid loading, high-impact loading and explosive tasks are likely detrimental for the IVD. Reduced physical activity and disuse appear to be detrimental for the IVD. We also consider the impact of genetics and the likelihood of a ‘critical period’ for the effect of exercise in IVD development. The current review summarises the literature to increase awareness amongst exercise, rehabilitation and ergonomic professionals regarding IVD health and provides recommendations on future directions in research.
KW  - Intradiscal Pressure
KW  - Annulus Fibrosus
KW  - Disc Degeneration
KW  - Nucleus Pulposus
KW  - Intervertebral Disc
Y1  - 2016
U6  - https://doi.org/10.1007/s40279-015-0444-2
SN  - 1179-2035
VL  - 46
IS  - 4
SP  - 473
EP  - 485
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Behnam, S.
A1  - Becker, A.
A1  - Weber, Hans-Joachim
T1  - Clinical benefit and cost-efficiency of minimized perfusion  circuits for extracorporeal circulation during cardiac surgery
JF  - Zeitschrift für Herz-, Thorax- und Gefäßchirurgie
Y1  - 2011
SN  - 0930-9225
N1  - Abstracts der 40. Internationalen  Jahrestagung der DGfK  und 3. Fokustagung Herz Kardiotechnik – Intensivmedizin – Herzchirurgie –  Rhythmustherapie 11. bis 13. November 2011 in Weimar
VL  - 25
IS  - 5
SP  - 305
EP  - 306
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Behbahani, Mehdi
A1  - Waluga, C.
A1  - Stock, S.
A1  - Mai, A.
A1  - Bergmann, B.
A1  - Behr, M.
A1  - Tran, L.
A1  - Vonderstein, K.
A1  - Scheidt, H.
A1  - Oedekoven, B.
A1  - Mottaghy, K.
T1  - Modelling and Numerical Analysis of Platelet Reactions and Surface Thrombus Growth
Y1  - 2009
N1  - Posterpresentation ; European Society of Biomaterials (ESB), Lausanne, Switzerland, September 7-10, 2009
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  - Behbahani, Mehdi
A1  - Tran, L.
A1  - Waluga, C.
A1  - Behr, M.
A1  - Oedekoven, B.
A1  - Mottaghy, K.
T1  - Model-based Numerical Analysis of Platelet Adhesion, Thrombus Growth and Aggregation for Assist Devices
JF  - The International Journal of Artificial Organs. 32 (2009), H. 7
Y1  - 2009
SN  - 0391-3988
N1  - Abstracts - Oral Presentations: XXXVI Annual ESAO Congress, 2-5 September 2009, Compiègne - France; European Society of Artificial Organs (ESAO), Compiegne, France, September 2-5, 2009
SP  - 398
EP  - 398
ER  - 
TY  - JOUR
A1  - Behbahani, Mehdi
A1  - Tran, L.
A1  - Jockenhövel, S.
A1  - Behr, M.
A1  - Mottaghy, K.
T1  - Numerical prediction of thrombocyte reactions for application to a vascular flow model
JF  - British Journal of Surgery
Y1  - 2011
SN  - 1365-2168
N1  - 46th Congress of the European Society for Surgical Research, Aachen, Germany, 25-28 May 2011 ; ESSR Abstracts 2011 ; Oral Sessions OP10-5
VL  - 98
IS  - S5
SP  - S17
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - CHAP
A1  - Behbahani, Mehdi
A1  - Rible, Sebastian
A1  - Moulinec, Charles
A1  - Fournier, Yvan
A1  - Nicolai, Mike
A1  - Crosetto, Paolo
T1  - Simulation of the FDA Centrifugal Blood Pump Using High Performance Computing
T2  - World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering
Y1  - 2015
VL  - 9
IS  - 5
ER  - 
TY  - JOUR
A1  - Behbahani, Mehdi
A1  - Probst, M.
A1  - Mai, A.
A1  - Tran, L.
A1  - Vonderstein, K.
A1  - Keschenau, P.
A1  - Linde, T.
A1  - Steinseifer, U.
A1  - Behr, M.
A1  - Mottaghy, K.
T1  - The influence of high shear on thrombosis and hemolysis in artificial organs
JF  - Artificial Organs
Y1  - 2010
SN  - 0391-3988
N1  - Special Issue: SI ; Meeting abstract
VL  - 33
IS  - 7
SP  - 426
EP  - 426
ER  - 
TY  - JOUR
A1  - Behbahani, Mehdi
A1  - Probst, M.
A1  - Mai, A.
A1  - Behr, M.
A1  - Tran, L.
A1  - Vonderstein, K.
A1  - Mottaghy, K.
T1  - Numerical Prediction of Blood Damage in Biomedical Devices
Y1  - 2010
N1  - Posterpresentation ; Biomedica Congress, Aachen, March 17-18, 2010
ER  -