TY  - JOUR
A1  - Jung, Alexander
A1  - Müller, Wolfram
A1  - Staat, Manfred
T1  - Wind and fairness in ski jumping: A computer modelling analysis
JF  - Journal of Biomechanics
N2  - Wind is closely associated with the discussion of fairness in ski jumping. To counter-act its influence on the jump length, the International Ski Federation (FIS) has introduced a wind compensation approach. We applied three differently accurate computer models of the flight phase with wind (M1, M2, and M3) to study the jump length effects of various wind scenarios. The previously used model M1 is accurate for wind blowing in direction of the flight path, but inaccuracies are to be expected for wind directions deviating from the tangent to the flight path. M2 considers the change of airflow direction, but it does not consider the associated change in the angle of attack of the skis which additionally modifies drag and lift area time functions. M3 predicts the length effect for all wind directions within the plane of the flight trajectory without any mathematical simplification. Prediction errors of M3 are determined only by the quality of the input data: wind velocity, drag and lift area functions, take-off velocity, and weight. For comparing the three models, drag and lift area functions of an optimized reference jump were used. Results obtained with M2, which is much easier to handle than M3, did not deviate noticeably when compared to predictions of the reference model M3. Therefore, we suggest to use M2 in future applications. A comparison of M2 predictions with the FIS wind compensation system showed substantial discrepancies, for instance: in the first flight phase, tailwind can increase jump length, and headwind can decrease it; this is opposite of what had been anticipated before and is not considered in the current wind compensation system in ski jumping.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.jbiomech.2018.05.001
SN  - 0021-9290
IS  - 75
SP  - 147
EP  - 153
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Temiz Artmann, Aysegül
A1  - Kayser, Peter
T1  - Why is Sepsis an Ongoing Clinical Challenge? Lipopolysaccharide Effects on Red Blood Cell Volume / Temiz, Aysegül ;  Kayser, Peter
JF  - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)
Y1  - 2008
SN  - 978-3-540-75408-4
SP  - 497
EP  - 508
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Akimbekov, Nuraly S.
A1  - Digel, Ilya
A1  - Sherelkhan, Dinara K.
A1  - Lutfor, Afzalunnessa B.
A1  - Razzaque, Mohammed S.
T1  - Vitamin D and the Host-Gut Microbiome: A Brief Overview
JF  - Acta Histochemica et Cytochemica
N2  - There is a growing body of evidence for the effects of vitamin D on intestinal host-microbiome interactions related to gut dysbiosis and bowel inflammation. This brief review highlights the potential links between vitamin D and gut health, emphasizing the role of vitamin D in microbiological and immunological mechanisms of inflammatory bowel diseases. A comprehensive literature search was carried out in PubMed and Google Scholar using combinations of keywords “vitamin D,” “intestines,” “gut microflora,” “bowel inflammation”. Only articles published in English and related to the study topic are included in the review. We discuss how vitamin D (a) modulates intestinal microbiome function, (b) controls antimicrobial peptide expression, and (c) has a protective effect on epithelial barriers in the gut mucosa. Vitamin D and its nuclear receptor (VDR) regulate intestinal barrier integrity, and control innate and adaptive immunity in the gut. Metabolites from the gut microbiota may also regulate expression of VDR, while vitamin D may influence the gut microbiota and exert anti-inflammatory and immune-modulating effects. The underlying mechanism of vitamin D in the pathogenesis of bowel diseases is not fully understood, but maintaining an optimal vitamin D status appears to be beneficial for gut health. Future studies will shed light on the molecular mechanisms through which vitamin D and VDR interactions affect intestinal mucosal immunity, pathogen invasion, symbiont colonization, and antimicrobial peptide expression.
Y1  - 2020
U6  - http://dx.doi.org/10.1267/ahc.20011
SN  - 1347-5800
VL  - 53
IS  - 3
SP  - 33
EP  - 42
PB  - Japan Society of Histochemistry and Cytochemistry
CY  - Osaka
ER  - 
TY  - JOUR
A1  - Ullrich, Sebastian
A1  - Grottke, Oliver
A1  - Rossaint, Rolf
A1  - Staat, Manfred
A1  - Deserno, Thomas M.
A1  - Kuhlen, Torsten
T1  - Virtual Needle Simulation with Haptics for Regional Anaesthesia
Y1  - 2010
N1  - IEEE Virtual Reality 2010, Workshop on Medical Virtual Environments, Waltham, MA, USA, March 21, 2010
SP  - 1
EP  - 3
ER  - 
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  - http://dx.doi.org/10.3390/biomechanics2020013
SN  - 2673-7078
VL  - 2
IS  - 2
SP  - 138
EP  - 157
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Conzen, Catharina
A1  - Albanna, Walid
A1  - Weiss, Miriam
A1  - Kürten, David
A1  - Vilser, Walthard
A1  - Kotliar, Konstantin
A1  - Zäske, Charlotte
A1  - Clusmann, Hans
A1  - Schubert, Gerrit Alexander
T1  - Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes
JF  - Translational Stroke Research
N2  - Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5–14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome.
Y1  - 2018
U6  - http://dx.doi.org/10.1007/s12975-017-0585-8
SN  - 1868-601X
IS  - 9
SP  - 284
EP  - 293
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - German, Laura
A1  - Mikucki, Jill A.
A1  - Welch, Susan A.
A1  - Welch, Kathleen A.
A1  - Lutton, Anthony
A1  - Dachwald, Bernd
A1  - Kowalski, Julia
A1  - Heinen, Dirk
A1  - Feldmann, Marco
A1  - Francke, Gero
A1  - Espe, Clemens
A1  - Lyons, W. Berry
T1  - Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry
JF  - International Journal of Environmental Analytical Chemistry
N2  - Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe’s sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2−+NO3− from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.
Y1  - 2021
U6  - http://dx.doi.org/10.1080/03067319.2019.1704750
SN  - 0306-7319
VL  - 101
IS  - 15
SP  - 2654
EP  - 2667
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Zange, Jochen
A1  - Schopen, Kathrin
A1  - Albracht, Kirsten
A1  - Gerlach, Darius A.
A1  - Frings-Meuthen, Petra
A1  - Maffiuletti, Nicola A.
A1  - Bloch, Wilhelm
A1  - Rittweger, Jörn
T1  - Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial
JF  - Plos one
Y1  - 2017
U6  - http://dx.doi.org/10.1371/journal.pone.0171562
VL  - 12
IS  - 2
ER  - 
TY  - JOUR
A1  - Garhofer, Gerhard
A1  - Bek, Toke
A1  - Boehm, Andreas G.
A1  - Gherghel, Doina
A1  - Grundwald, Juan
A1  - Jeppesen, Peter
A1  - Kergoat, Hélène
A1  - Kotliar, Konstantin
A1  - Lanzl, Ines
A1  - Lovasik, John V.
A1  - Nagel, Edgar
A1  - Vilser, Walthard
A1  - Orgul, Selim
A1  - Schmetterer, Leopold
T1  - Use of the retinal vessel analyzer in ocular blood flow research
JF  - Acta Ophthalmol
N2  - The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed.
Y1  - 2010
U6  - http://dx.doi.org/10.1111/j.1755-3768.2009.01587.x
SN  - 1755-3768
VL  - 88
IS  - 7
SP  - 717
EP  - 722
PB  - Wiley-Blackwell
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Akimbekov, N. Sh.
A1  - Zhubanova, A. A.
A1  - Mansurov, Z. A.
A1  - Digel, Ilya
A1  - Artmann, Gerhard
A1  - Temiz Artmann, Aysegül
T1  - Use of Carbonized Rise Shell for the local treatment of wounds
JF  - Eurasian ChemTech Journal
N2  - On the model of musculocutaneous wound in rats, the effect of applicative sorption by carbonized rise shell (CRS) on the healing of festering wound was studied. It has been shown, that cytological changes end with rapid scar formation. The use of CRS at the period of severe purulent wound contributes to its favorable course, prevents the development of complications of the animals from sepsis.
Y1  - 2010
U6  - http://dx.doi.org/10.18321/ectj35
SN  - 2522-4867
VL  - 12
IS  - 2
SP  - 133
EP  - 138
PB  - Institute of Combustion Problems
CY  - Almaty
ER  -