TY - JOUR A1 - Artmann, Gerhard A1 - Sung, K.-L. Paul A1 - Horn, Thomas A1 - Whittemore, Darren [u.a.] T1 - Micropipette aspiration of human erythrocytes induces echinocytes via membrane phospholipid translocation. Artmann, Gerhard Michael; Sung, K.-L. Paul; Horn, Thomas; Whittemore, Darren; Norwich, Gerald; Chien, Shu JF - Biophysical journal. 72 (1997), H. 3 Y1 - 1997 SN - 1542-0086 SP - 1434 EP - 1441 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, J. A1 - Schmid-Schönbein, G. W. T1 - Investigation on lymphatic endothelial microvalves / Trzewik, J. ; Artmann, G. M. ; Schmid-Schönbein, G. W. JF - Biomedizinische Technik = Biomedical Engineering. 45 (2000), H. s1 Y1 - 2000 SN - 1862-278X SP - 521 EP - 522 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, Jürgen A1 - Ates, M. T1 - A novel method to quantify mechanical tension in cell monolayers. Trzewik, Jürgen; Ates, M., Artmann, Gerhard Michael JF - Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1 Y1 - 2002 SN - 0013-5585 N1 - Druckausgabe unter 63 Z 47 vorhanden SP - 379 EP - 381 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, Jürgen A1 - Mallipattu, S. K. A1 - Delano, F. A. [u.a.] T1 - Evidence for a second valve system in Lymphatics: Endothelial Microvalves. Trzewik, Jürgen; Mallipattu, S. K.; Artmann, Gerhard Michael; Delano, F. A.; Schmid-Schonbein, G. W JF - The FASEB Journal. 15 (2001) Y1 - 2001 SN - 1530-6860 SP - 1711 EP - 1717 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zang, Werner T1 - Fully automatic measurement of rheologic parameters of red blood cells = Laborautomat zur Messung mechanischer Eigenschaften roter Blutzellen JF - Biomedizinische Technik = Biomedical engineering. 35 (1990), H. Suppl. 3 Y1 - 1990 SN - 0013-5585 SP - 94 EP - 96 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zerlin, Kay A1 - Digel, Ilya T1 - Hemoglobin Senses Body Temperature JF - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.) Y1 - 2008 SN - 978-3-540-75408-4 SP - 415 EP - 447 PB - Springer CY - Berlin ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zerlin, Kay A1 - Digel, Ilya A1 - Stadler, Andreas M. T1 - Physical discontinuities at body temperature in human red blood cells / Artmann, GM ; Zerlin, K ; Digel, I ; Stadler, A ; Zaccai, G ; Temiz, AA JF - Tissue Engineering. 13 (2007), H. 7 Y1 - 2007 SN - 1076-3279 N1 - TERMIS-EU Meeting Abstracts London, UK September 4–7, 2007 SP - 1778 EP - 1778 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zhou-Stache, J. A1 - Buettner, R. A1 - Mittermayer, C. [u.a.] T1 - Inhibition of TNF-alpha induced cell death in HUVEC and Jurkat cells by protocatechuic acid. Zhou-Stache, J.; Buettner, R.; Artmann, Gerhard Michael; Mittermayer, C.; Bosserhoff, A. K. JF - Medical and Biological Engineering and Computing. 40 (2002), H. 6 Y1 - 2002 SN - 0140-0118 SP - 698 EP - 703 ER - TY - JOUR A1 - Atlas, Glen A1 - Brealey, David A1 - Dhar, Sunil A1 - Dikta, Gerhard A1 - Singer, Meryvn T1 - Additional hemodynamic measurements with an esophageal Doppler monitor: a preliminary report of compliance, force, kinetic energy, and afterload in the clinical setting JF - Journal of clinical monitoring and computing N2 - The esophageal Doppler monitor (EDM) is a minimally-invasive hemodynamic device which evaluates both cardiac output (CO), and fluid status, by estimating stroke volume (SV) and calculating heart rate (HR). The measurement of these parameters is based upon a continuous and accurate approximation of distal thoracic aortic blood flow. Furthermore, the peak velocity (PV) and mean acceleration (MA), of aortic blood flow at this anatomic location, are also determined by the EDM. The purpose of this preliminary report is to examine additional clinical hemodynamic calculations of: compliance (C), kinetic energy (KE), force (F), and afterload (TSVRi). These data were derived using both velocity-based measurements, provided by the EDM, as well as other contemporaneous physiologic parameters. Data were obtained from anesthetized patients undergoing surgery or who were in a critical care unit. A graphical inspection of these measurements is presented and discussed with respect to each patient’s clinical situation. When normalized to each of their initial values, F and KE both consistently demonstrated more discriminative power than either PV or MA. The EDM offers additional applications for hemodynamic monitoring. Further research regarding the accuracy, utility, and limitations of these parameters is therefore indicated. KW - Acceleration KW - Velocity KW - Kinetic energy KW - Force KW - Compliance KW - Afterload KW - Contractility KW - Volume status KW - Esophageal Doppler monitor Y1 - 2012 SN - 1573-2614 U6 - http://dx.doi.org/10.1007/s10877-012-9386-5 IS - 26 SP - 473 EP - 482 PB - Springer Nature CY - London ER - TY - JOUR A1 - Attar, Mandana Hossein Zadeh A1 - Merk, Hans F. A1 - Kotliar, Konstantin A1 - Wurpts, Gerda A1 - Röseler, Stefani A1 - Moll-Slodowy, Silke A1 - Plange, Johann A1 - Baron, Jens Malte A1 - Balakirski, Galina T1 - The CD63 basophil activation test as a diagnostic tool for assessing autoimmunity in patients with chronic spontaneous urticaria JF - European Journal of Dermatology Y1 - 2019 U6 - http://dx.doi.org/10.1684/ejd.2019.3680 VL - 29 IS - 6 SP - 614 EP - 618 ER - TY - JOUR A1 - Auffray, E. A1 - Bruyndonckx, P. A1 - Devroede, O. A1 - Fedorov, A. A1 - Ziemons, Karl T1 - The ClearPET project JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment N2 - The Crystal Clear Collaboration has designed and is building a high-resolution small animal PET scanner. The design is based on the use of the Hamamatsu R7600-M64 multi-anode photomultiplier tube and a LSO/LuYAP phoswich matrix with one to one coupling between the crystals and the photo-detector. The complete system will have 80 PM tubes in four rings with an inner diameter of 137 mm and an axial field of view of 110 mm. The PM pulses are digitized by free-running ADCs and digital data processing determines the gamma energy, the phoswich layer and even the pulse arrival time. Single gamma interactions are recorded and coincidences are found by software. The gantry allows rotation of the detector modules around the field of view. Simulations, and measurements a 2×4 module test set-up predict a spatial resolution of 1.5 mm in the centre of the field of view and a sensitivity of 5.9% for a point source in the centre of the field of view. Y1 - 2004 SN - 0168-9002 N1 - Proceedings of the 2nd International Conference on Imaging Technologies in Biomedical Sciences VL - 527 IS - 1-2 SP - 171 EP - 174 ER - TY - JOUR A1 - Ayala, Rafael Ceja A1 - Harris, Isaac A1 - Kleefeld, Andreas A1 - Pallikarakis, Nikolaos T1 - Analysis of the transmission eigenvalue problem with two conductivity parameters JF - Applicable Analysis N2 - In this paper, we provide an analytical study of the transmission eigenvalue problem with two conductivity parameters. We will assume that the underlying physical model is given by the scattering of a plane wave for an isotropic scatterer. In previous studies, this eigenvalue problem was analyzed with one conductive boundary parameter whereas we will consider the case of two parameters. We prove the existence and discreteness of the transmission eigenvalues as well as study the dependence on the physical parameters. We are able to prove monotonicity of the first transmission eigenvalue with respect to the parameters and consider the limiting procedure as the second boundary parameter vanishes. Lastly, we provide extensive numerical experiments to validate the theoretical work. KW - Transmission Eigenvalues KW - Conductive Boundary Condition KW - Inverse Scattering Y1 - 2023 U6 - http://dx.doi.org/10.1080/00036811.2023.2181167 SN - 0003-6811 PB - Taylor & Francis ER - TY - JOUR A1 - Balakirski, Galina A1 - Kotliar, Konstantin A1 - Pauly, Karolin J. A1 - Krings, Laura K. A1 - Rübben, Albert A1 - Baron, Jens M. A1 - Schmitt, Laurenz T1 - Surgical Site Infections After Dermatologic Surgery in Immunocompromised Patients: A Single-Center Experience JF - Dermatologic Surgery N2 - BACKGROUND Immunosuppression is often considered as an indication for antibiotic prophylaxis to prevent surgical site infections (SSI) while performing skin surgery. However, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. PATIENTS AND METHODS All patients of the Department of Dermatology and Allergology at the University Hospital of RWTH Aachen in Aachen, Germany, who underwent hospitalization for a dermatologic surgery between June 2016 and January 2017 (6 months), were followed up after surgery until completion of the wound healing process. The follow-up addressed the occurrence of SSI and the need for systemic antibiotics after the operative procedure. Immunocompromised patients were compared with immunocompetent patients. The investigation was conducted as a retrospective analysis of patient records. RESULTS The authors performed 284 dermatologic surgeries in 177 patients. Nineteen percent (54/284) of the skin surgery was performed on immunocompromised patients. The most common indications for surgical treatment were nonmelanoma skin cancer and malignant melanomas. Surgical site infections occurred in 6.7% (19/284) of the cases. In 95% (18/19), systemic antibiotic treatment was needed. Twenty-one percent of all SSI (4/19) were seen in immunosuppressed patients. CONCLUSION According to the authors' data, immunosuppression does not represent a significant risk factor for SSI after dermatologic surgery. However, larger prospective studies are needed to make specific recommendations on the use of antibiotic prophylaxis while performing skin surgery in these patients. The available data on complications after dermatologic surgery have improved over the past years. Particularly, additional risk factors have been identified for surgical site infections (SSI). Purulent surgical sites, older age, involvement of head, neck, and acral regions, and also the involvement of less experienced surgeons have been reported to increase the risk of the SSI after dermatologic surgeries.1 In general, the incidence of SSI after skin surgery is considered to be low.1,2 However, antibiotics in dermatologic surgeries, especially in the perioperative setting, seem to be overused,3,4 particularly regarding developing antibiotic resistances and side effects. Immunosuppression has been recommended to be taken into consideration as an additional indication for antibiotic prophylaxis to prevent SSI after skin surgery in special cases.5,6 However, these recommendations do not specify the exact dermatologic surgeries, and were not specifically developed for dermatologic surgery patients and treatments, but adopted from other surgical fields.6 According to the survey conducted on American College of Mohs Surgery members in 2012, 13% to 29% of the surgeons administered antibiotic prophylaxis to immunocompromised patients to prevent SSI while performing dermatologic surgery on noninfected skin,3 although this was not recommended by Journal of the American Academy of Dermatology Advisory Statement. Indeed, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. However, it is possible that due to the insufficient evidence on the risk of SSI occurrence in this patient group, dermatologic surgeons tend to overuse perioperative antibiotic prophylaxis. To make specific recommendations on the use of antibiotic prophylaxis in immunosuppressed patients in the field of skin surgery, more information about the incidence of SSI after dermatologic surgery in these patients is needed. The aim of this study was to fill this data gap by investigating whether there is an increased risk of SSI after skin surgery in immunocompromised patients compared with immunocompetent patients. Y1 - 2018 U6 - http://dx.doi.org/10.1097/DSS.0000000000001615 IS - 44 (12) SP - 1525 EP - 1536 PB - Wolters Kluwer ER - TY - JOUR A1 - Ball, Christopher Stephen A1 - Vögele, Stefan A1 - Grajewski, Matthias A1 - Kuckshinrichs, Wilhelm T1 - E-mobility from a multi-actor point of view: Uncertainties and their impacts JF - Technological Forecasting and Social Change Y1 - 2021 SN - 0040-1625 U6 - http://dx.doi.org/10.1016/j.techfore.2021.120925 VL - 170 IS - Art. 120925 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bandodkar, Amay J. A1 - Molinnus, Denise A1 - Mirza, Omar A1 - Guinovart, Tomas A1 - Windmiller, Joshua R. A1 - Valdes-Ramirez, Gabriela A1 - Andrade, Francisco J. A1 - Schöning, Michael Josef A1 - Wang, Joseph T1 - Epidermal tattoo potentiometric sodium sensors with wireless signal transduction for continuous non-invasive sweat monitoring JF - Biosensors and bioelectronics N2 - This article describes the fabrication, characterization and application of an epidermal temporary-transfer tattoo-based potentiometric sensor, coupled with a miniaturized wearable wireless transceiver, for real-time monitoring of sodium in the human perspiration. Sodium excreted during perspiration is an excellent marker for electrolyte imbalance and provides valuable information regarding an individual's physical and mental wellbeing. The realization of the new skin-worn non-invasive tattoo-like sensing device has been realized by amalgamating several state-of-the-art thick film, laser printing, solid-state potentiometry, fluidics and wireless technologies. The resulting tattoo-based potentiometric sodium sensor displays a rapid near-Nernstian response with negligible carryover effects, and good resiliency against various mechanical deformations experienced by the human epidermis. On-body testing of the tattoo sensor coupled to a wireless transceiver during exercise activity demonstrated its ability to continuously monitor sweat sodium dynamics. The real-time sweat sodium concentration was transmitted wirelessly via a body-worn transceiver from the sodium tattoo sensor to a notebook while the subjects perspired on a stationary cycle. The favorable analytical performance along with the wearable nature of the wireless transceiver makes the new epidermal potentiometric sensing system attractive for continuous monitoring the sodium dynamics in human perspiration during diverse activities relevant to the healthcare, fitness, military, healthcare and skin-care domains. Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.bios.2013.11.039 SN - 1873-4235 (E-Journal); 0956-5663 (Print) VL - 54 SP - 603 EP - 609 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Baringhaus, Ludwig A1 - Gaigall, Daniel T1 - A goodness-of-fit test for the compound Poisson exponential model JF - Journal of Multivariate Analysis N2 - On the basis of bivariate data, assumed to be observations of independent copies of a random vector (S,N), we consider testing the hypothesis that the distribution of (S,N) belongs to the parametric class of distributions that arise with the compound Poisson exponential model. Typically, this model is used in stochastic hydrology, with N as the number of raindays, and S as total rainfall amount during a certain time period, or in actuarial science, with N as the number of losses, and S as total loss expenditure during a certain time period. The compound Poisson exponential model is characterized in the way that a specific transform associated with the distribution of (S,N) satisfies a certain differential equation. Mimicking the function part of this equation by substituting the empirical counterparts of the transform we obtain an expression the weighted integral of the square of which is used as test statistic. We deal with two variants of the latter, one of which being invariant under scale transformations of the S-part by fixed positive constants. Critical values are obtained by using a parametric bootstrap procedure. The asymptotic behavior of the tests is discussed. A simulation study demonstrates the performance of the tests in the finite sample case. The procedure is applied to rainfall data and to an actuarial dataset. A multivariate extension is also discussed. KW - Bootstrapping KW - Collective risk model Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.jmva.2022.105154 SN - 0047-259X SN - 1095-7243 VL - 195 IS - Article 105154 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Baringhaus, Ludwig A1 - Gaigall, Daniel T1 - On Hotelling’s T² test in a special paired sample case JF - Communications in Statistics - Theory and Methods N2 - In a special paired sample case, Hotelling’s T² test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given. KW - complete block symmetry KW - Hotelling’s T² test KW - likelihood ratio test KW - uniformly most powerful invariant test Y1 - 2017 U6 - http://dx.doi.org/10.1080/03610926.2017.1408828 SN - 1532-415X VL - 48 IS - 2 SP - 257 EP - 267 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Baringhaus, Ludwig A1 - Gaigall, Daniel T1 - Hotelling’s T² tests in paired and independent survey samples: An efficiency comparison JF - Journal of Multivariate Analysis N2 - Hotelling’s T² tests in paired and independent survey samples are compared using the traditional asymptotic efficiency concepts of Hodges–Lehmann, Bahadur and Pitman, as well as through criteria based on the volumes of corresponding confidence regions. Conditions characterizing the superiority of a procedure are given in terms of population canonical correlation type coefficients. Statistical tests for checking these conditions are developed. Test statistics based on the eigenvalues of a symmetrized sample cross-covariance matrix are suggested, as well as test statistics based on sample canonical correlation type coefficients. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.jmva.2016.11.004 SN - 0047-259X VL - 2017 IS - 154 SP - 177 EP - 198 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Baringhaus, Ludwig A1 - Gaigall, Daniel T1 - On an independence test approach to the goodness-of-fit problem JF - Journal of Multivariate Analysis N2 - Let X₁,…,Xₙ be independent and identically distributed random variables with distribution F. Assuming that there are measurable functions f:R²→R and g:R²→R characterizing a family F of distributions on the Borel sets of R in the way that the random variables f(X₁,X₂),g(X₁,X₂) are independent, if and only if F∈F, we propose to treat the testing problem H:F∈F,K:F∉F by applying a consistent nonparametric independence test to the bivariate sample variables (f(Xᵢ,Xⱼ),g(Xᵢ,Xⱼ)),1⩽i,j⩽n,i≠j. A parametric bootstrap procedure needed to get critical values is shown to work. The consistency of the test is discussed. The power performance of the procedure is compared with that of the classical tests of Kolmogorov–Smirnov and Cramér–von Mises in the special cases where F is the family of gamma distributions or the family of inverse Gaussian distributions. KW - Goodness-of-fit test KW - Independence test KW - Parametric bootstrap KW - Vapnik–Čhervonenkis class KW - Gamma distribution Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.jmva.2015.05.013 SN - 0047-259X VL - 2015 IS - 140 SP - 193 EP - 208 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Baringhaus, Ludwig A1 - Gaigall, Daniel T1 - On an asymptotic relative efficiency concept based on expected volumes of confidence regions JF - Statistics - A Journal of Theoretical and Applied Statistic N2 - The paper deals with an asymptotic relative efficiency concept for confidence regions of multidimensional parameters that is based on the expected volumes of the confidence regions. Under standard conditions the asymptotic relative efficiencies of confidence regions are seen to be certain powers of the ratio of the limits of the expected volumes. These limits are explicitly derived for confidence regions associated with certain plugin estimators, likelihood ratio tests and Wald tests. Under regularity conditions, the asymptotic relative efficiency of each of these procedures with respect to each one of its competitors is equal to 1. The results are applied to multivariate normal distributions and multinomial distributions in a fairly general setting. KW - Volume of confidence regions KW - asymptotic relative efficiency KW - likelihood ratio test KW - multivariate normal distribution KW - multinomial distribution Y1 - 2019 U6 - http://dx.doi.org/10.1080/02331888.2019.1683560 SN - 1029-4910 VL - 53 IS - 6 SP - 1396 EP - 1436 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Baringhaus, Ludwig A1 - Gaigall, Daniel A1 - Thiele, Jan Philipp T1 - Statistical inference for L²-distances to uniformity JF - Computational Statistics N2 - The paper deals with the asymptotic behaviour of estimators, statistical tests and confidence intervals for L²-distances to uniformity based on the empirical distribution function, the integrated empirical distribution function and the integrated empirical survival function. Approximations of power functions, confidence intervals for the L²-distances and statistical neighbourhood-of-uniformity validation tests are obtained as main applications. The finite sample behaviour of the procedures is illustrated by a simulation study. KW - Integrated empirical distribution (survival) function KW - Goodness-of-fit tests for uniformity KW - Numerical inversion of Laplace transforms KW - Coverage probability KW - Equivalence test Y1 - 2018 U6 - http://dx.doi.org/10.1007/s00180-018-0820-0 SN - 1613-9658 VL - 2018 IS - 33 SP - 1863 EP - 1896 PB - Springer CY - Berlin ER - TY - JOUR A1 - Baroud, G. A1 - Wu, J.Z. A1 - Bohner, M A1 - Sponagel, Stefan A1 - Steffen, T. T1 - How to determine the permeability for cement infiltration into osteoporotic cancellous bone JF - Medical Engineering & Physics. 25 (2003), H. 4 N2 - Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice. KW - Osteoporose KW - Permeabilität KW - Viskose Strömung KW - Viskosität KW - Vertebroplastie KW - Cement infiltration KW - Vertebroplasty KW - Osteoporosis KW - Permeability KW - Experiment KW - Analysis KW - Viscous flow Y1 - 2003 SN - 1350-4533 SP - 283 EP - 288 ER - TY - JOUR A1 - Bassam, Rasha A1 - Artmann, Gerhard A1 - Hescheler, Jürgen A1 - Graef, T. A1 - Temiz Artmann, Aysegül A1 - Porst, Dariusz A1 - Linder, Peter A1 - Kayser, Peter A1 - Arinkin, Vladimir A1 - Gossmann, Matthias A1 - Digel, Ilya T1 - Alterations in human hemoglobin structure related to red blood cell storage N2 - The importance of the availability of stored blood or blood cells, respectively, for urgent transfusion cannot be overestimated. Nowadays, blood storage becomes even more important since blood products are used for epidemiological studies, bio-technical research or banked for transfusion purposes. Thus blood samples must not only be processed, stored, and shipped to preserve their efficacy and safety, but also all parameters of storage must be recorded and reported for Quality Assurance. Therefore, blood banks and clinical research facilities are seeking more accurate, automated means for blood storage and blood processing. KW - Hämoglobin KW - Hämoglobinstruktur KW - Blutzellenlagerung KW - Hemoglobin structure KW - Red blood cell storage Y1 - 2011 ER - TY - JOUR A1 - Bassam, Rasha A1 - Digel, Ilya A1 - Hescheler, Jürgen A1 - Temiz Artmann, Aysegül A1 - Artmann, Gerhard T1 - Effects of spermine NONOate and ATP on protein aggregation: light scattering evidences JF - BMC Biophysics Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?10.1186/2046-1682-6-1 SN - 2046-1682 SP - 1 EP - 14 PB - BioMed Central CY - London ER - TY - JOUR A1 - Bassam, Rasha A1 - Hescheler, Jürgen A1 - Temiz Artmann, Aysegül A1 - Artmann, Gerhard A1 - Digel, Ilya T1 - Effects of spermine NONOate and ATP on the thermal stability of hemoglobin JF - BMC Biophysics N2 - Background Minor changes in protein structure induced by small organic and inorganic molecules can result in significant metabolic effects. The effects can be even more profound if the molecular players are chemically active and present in the cell in considerable amounts. The aim of our study was to investigate effects of a nitric oxide donor (spermine NONOate), ATP and sodium/potassium environment on the dynamics of thermal unfolding of human hemoglobin (Hb). The effect of these molecules was examined by means of circular dichroism spectrometry (CD) in the temperature range between 25°C and 70°C. The alpha-helical content of buffered hemoglobin samples (0.1 mg/ml) was estimated via ellipticity change measurements at a heating rate of 1°C/min. Results Major results were: 1) spermine NONOate persistently decreased the hemoglobin unfolding temperature T u irrespectively of the Na + /K + environment, 2) ATP instead increased the unfolding temperature by 3°C in both sodium-based and potassium-based buffers and 3) mutual effects of ATP and NO were strongly influenced by particular buffer ionic compositions. Moreover, the presence of potassium facilitated a partial unfolding of alpha-helical structures even at room temperature. Conclusion The obtained data might shed more light on molecular mechanisms and biophysics involved in the regulation of protein activity by small solutes in the cell. KW - Nitric Oxide Donor KW - NONOate KW - Circular Dichroism KW - Nitric Oxide Y1 - 2012 U6 - http://dx.doi.org/10.1186/2046-1682-5-16 SN - 2046-1682 VL - 5 PB - BioMed Central CY - London ER - TY - JOUR A1 - Baumann, Marcus A1 - Schwarz, Sonja A1 - Kotliar, Konstantin A1 - Eynatten, Maximilian von A1 - Trucksaess, Arno A1 - Burckhardt, Klaus A1 - Lutz, Jens A1 - Heemann, Uwe A1 - Lanzl, Ines T1 - Non-diabetic chronic kidney disease influences retinal microvasculature JF - Kidney and Blood Pressure Research Y1 - 2009 SN - 1423-0143 VL - 32 IS - 6 SP - 428 EP - 433 PB - - ER - TY - JOUR A1 - Bayer, Robin A1 - Temiz Artmann, Aysegül A1 - Digel, Ilya A1 - Falkenstein, Julia A1 - Artmann, Gerhard A1 - Creutz, Till A1 - Hescheler, Jürgen T1 - Mechano-pharmacological testing of L-Type Ca²⁺ channel modulators via human vascular celldrum model JF - Cellular Physiology and Biochemistry N2 - Background/Aims: This study aimed to establish a precise and well-defined working model, assessing pharmaceutical effects on vascular smooth muscle cell monolayer in-vitro. It describes various analysis techniques to determine the most suitable to measure the biomechanical impact of vasoactive agents by using CellDrum technology. Methods: The so-called CellDrum technology was applied to analyse the biomechanical properties of confluent human aorta muscle cells (haSMC) in monolayer. The cell generated tensions deviations in the range of a few N/m² are evaluated by the CellDrum technology. This study focuses on the dilative and contractive effects of L-type Ca²⁺ channel agonists and antagonists, respectively. We analyzed the effects of Bay K8644, nifedipine and verapamil. Three different measurement modes were developed and applied to determine the most appropriate analysis technique for the study purpose. These three operation modes are called, particular time mode" (PTM), "long term mode" (LTM) and "real-time mode" (RTM). Results: It was possible to quantify the biomechanical response of haSMCs to the addition of vasoactive agents using CellDrum technology. Due to the supplementation of 100nM Bay K8644, the tension increased approximately 10.6% from initial tension maximum, whereas, the treatment with nifedipine and verapamil caused a significant decrease in cellular tension: 10nM nifedipine decreased the biomechanical stress around 6,5% and 50nM verapamil by 2,8%, compared to the initial tension maximum. Additionally, all tested measurement modes provide similar results while focusing on different analysis parameters. Conclusion: The CellDrum technology allows highly sensitive biomechanical stress measurements of cultured haSMC monolayers. The mechanical stress responses evoked by the application of vasoactive calcium channel modulators were quantified functionally (N/m²). All tested operation modes resulted in equal findings, whereas each mode features operation-related data analysis. Y1 - 2020 U6 - http://dx.doi.org/10.33594/000000225 SN - 1421-9778 VL - 54 SP - 371 EP - 383 PB - Cell Physiol Biochem Press CY - Düsseldorf ER - TY - JOUR A1 - Becker, C. A1 - Wallang, C. A1 - Artmann, Gerhard A1 - Jakse, G. T1 - Mechanotransduction-bioreactor for tissue engineering of a ureter prosthesis JF - International Journal of Artificial Organs, The Y1 - 2008 SN - 0391-3988 N1 - Abstracts from the XXXV Congress of the European Society for Artificial Organs: 'Towards Future Biomedical Technologies' - ORAL PRESENTATIONS VL - 31 IS - 7 SP - 583 EP - 583 ER - TY - JOUR A1 - Beer, S. A1 - Streun, M. A1 - Hombach, T. A1 - Buehler, J. A1 - Jahnke, S. A1 - Khodaverdi, M. A1 - Larue, H. A1 - Minwuyelet, S. A1 - Parl, C. A1 - Roeb, G. A1 - Schurr, U. A1 - Ziemons, Karl T1 - Design and initial performance of PlanTIS: a high-resolution positron emission tomograph for plants JF - Physics in Medicine and Biology N2 - Positron emitters such as 11C, 13N and 18F and their labelled compounds are widely used in clinical diagnosis and animal studies, but can also be used to study metabolic and physiological functions in plants dynamically and in vivo. A very particular tracer molecule is 11CO2 since it can be applied to a leaf as a gas. We have developed a Plant Tomographic Imaging System (PlanTIS), a high-resolution PET scanner for plant studies. Detectors, front-end electronics and data acquisition architecture of the scanner are based on the ClearPET™ system. The detectors consist of LSO and LuYAP crystals in phoswich configuration which are coupled to position-sensitive photomultiplier tubes. Signals are continuously sampled by free running ADCs, and data are stored in a list mode format. The detectors are arranged in a horizontal plane to allow the plants to be measured in the natural upright position. Two groups of four detector modules stand face-to-face and rotate around the field-of-view. This special system geometry requires dedicated image reconstruction and normalization procedures. We present the initial performance of the detector system and first phantom and plant measurements. Y1 - 2010 U6 - http://dx.doi.org/10.1088/0031-9155/55/3/006 SN - 1361-6560 VL - 55 IS - 3 SP - 635 EP - 646 PB - IOP CY - Bristol ER - TY - JOUR A1 - Beging, Stefan A1 - Leinhos, Marcel A1 - Jablonski, Melanie A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Studying the spatially resolved immobilisation of enzymes on a capacitive field-effect structure by means of nano-spotting JF - Physica status solidi (a) Y1 - 2015 U6 - http://dx.doi.org/10.1002/pssa.201431891 SN - 1862-6319 VL - 212 IS - 6 SP - 1353 EP - 1358 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Beging, Stefan A1 - Mlynek, Daniela A1 - Hataihimakul, Sudkanung A1 - Poghossian, Arshak A1 - Baldsiefen, Gerhard A1 - Busch, Heinz A1 - Laube, Norbert A1 - Kleinen, Lisa A1 - Schöning, Michael Josef T1 - Field-effect calcium sensor for the determination of the risk of urinary stone formation JF - Sensors and Actuators B: Chemical. 144 (2010), H. 2 Y1 - 2010 N1 - 22nd International Conference on Eurosensors - Dresden, Germany, 7-10 September 2008 ; Eurosensors ; (22, 2008, Dresden) SP - 374 EP - 379 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Behr, M. A1 - Arora, D. A1 - Coronado, O. A1 - Pasquali, M. T1 - CFD Analysis of MicroMed Debakey Pump and Hemolysis Prediction / Behbahani, M. ; Behr, M. ; Arora, D. ; Coronado, O. ; Pasquali, M. JF - Artificial Organs. 30 (2006), H. 11 Y1 - 2006 SN - 1525-1594 N1 - Abstracts 14th Congress of the International Society for Rotary Blood Pumps, Leuven, Belgium, August 31–September 2, 2006 ; S7-4 SP - A45 EP - A46 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Behr, M. A1 - Hormes, M. A1 - Steinseifer, U. A1 - Arora, D. A1 - Coronado, O. A1 - Pasquali, M. T1 - A Review of Computational Fluid Dynamics Analysis of Blood Pumps JF - European Journal of Applied Mathematics. 20 (2009), H. 4 Y1 - 2009 SP - 363 EP - 397 PB - Cambridge Univ. Press CY - Cambridge ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Behr, Marek A1 - Nicolai, Mike A1 - Probst, Markus T1 - Towards Shape Optimization for Ventricular Assist Devices Using Parallel Stabilized FEM JF - NIC Symposium 2008 : symposium, 20 - 21 February 2008, Forschungszentrum Jülich ; proceedings / organized by John von Neumann Institute for Computing. Ed. by Gernot Münster; Dietrich Wolf; Manfred Kremer (ed.) Y1 - 2008 SN - 978-3-9810843-5-1 N1 - NIC series ; 39 SP - 325 EP - 332 PB - Forschungszentrum CY - Jülich ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Finocchiaro, Thomas A1 - Heinke, Stefanie A1 - Leßmann, Marc T1 - Methods of design, simulation, and control for the development of new VAD/TAH concepts = Methoden zur Konstruktion, Simulation und Regelung für die Entwicklung von neuen VAD/TAH-Konzepten / Finocchiaro, Thomas ; Heinke, Stefanie ; Behbahani, Mehdi ; Leßma JF - Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5 Y1 - 2009 SN - 0013-5585 N1 - Printausgabe in der Bereichsbibliothek Jülich vorhanden : 63 Z 471 SP - 269 EP - 281 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Mai, A. A1 - Bergmann, B. A1 - Waluga, C. A1 - Behr, M. A1 - Tran, L. A1 - Vonderstein, K. A1 - Mottaghy, K. T1 - Modeling and Numerical Simulation of Blood Damage Y1 - 2010 N1 - Posterpresentation ; Umbrella Symposium "Modelling and Simulation in Medicine, Engineering and Sciences", Forschungszentrum Jülich, January 18-20, 2010 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Mai, A. A1 - Waluga, C. A1 - Bergmann, B. A1 - Tran, L. A1 - Vonderstein, K. A1 - Behr, M. A1 - Mottaghy, K. T1 - Numerical Modeling of Flow-Related Thrombus Formation under Physiological and Non-Physiological Flow Conditions JF - Acta Physiologica Y1 - 2010 SN - 1748-1716 N1 - Joint Congress of the Scandinavian and German Physiological Societies, Copenhagen, Denmark, March 27-30, 2010 VL - 198 IS - Supplement 677 SP - 185 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Nam, J. A1 - Waluga, C. A1 - Behr, M. A1 - Pasquali, M. A1 - Mottaghy, K. T1 - Modeling and Numerical Analysis of Platelet Activation, Adhesion and Aggregation in Artificial Organs Y1 - 2010 U6 - http://dx.doi.org/10.1097/01.mat.0000369377.65122.a3 N1 - Posterpresentation American Society of Artificial Organs (ASAIO), Baltimore, USA, May 27-29, 2010 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Nicolai, M. A1 - Probst, M. A1 - Behr, M. T1 - Simulation of Blood Flow in a Ventricular Assist Device JF - inSIDE. 5 (2007), H. 1 Y1 - 2007 SP - 28 EP - 31 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - http://dx.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 - 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 - 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 - 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 - 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 - 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 - http://dx.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 - 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 - http://dx.doi.org/10.1002/pssa.202300866 SN - 1862-6319 (Online) SN - 1862-6300 (Print) IS - Early View PB - Wiley-VCH CY - Berlin 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 - Bhattarai, Aroj A1 - Jabbari, Medisa A1 - Anding, Ralf A1 - Staat, Manfred T1 - Surgical treatment of vaginal vault prolapse using different prosthetic mesh implants: a finite element analysis JF - tm - Technisches Messen N2 - Particularly multiparous elderly women may suffer from vaginal vault prolapse after hysterectomy due to weak support from lax apical ligaments. A decreased amount of estrogen and progesterone in older age is assumed to remodel the collagen thereby reducing tissue stiffness. Sacrocolpopexy is either performed as open or laparoscopic surgery using prosthetic mesh implants to substitute lax ligaments. Y-shaped mesh models (DynaMesh, Gynemesh, and Ultrapro) are implanted in a 3D female pelvic floor finite element model in the extraperitoneal space from the vaginal cuff to the first sacral (S1) bone below promontory. Numerical simulations are conducted during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues are modeled as incompressible, isotropic hyperelastic materials whereas the meshes are modeled either as orthotropic linear elastic or as isotropic hyperlastic materials. The positions of the vaginal cuff and the bladder base are calculated from the pubococcygeal line for female pelvic floor at rest, for prolapse and after repair using the three meshes. Due to mesh mechanics and mesh pore deformation along the loaded direction, the DynaMesh with regular rectangular mesh pores is found to provide better mechanical support to the organs than the Gynemesh and the Ultrapro with irregular hexagonal mesh pores. Insbesondere ältere, mehrgebährende Frauen leiden häufiger an einem Scheidenvorfall nach einer Hysterektomie aufgrund der schwachen Unterstützung durch laxe apikale Bänder. Es wird angenommen, dass eine verringerte Menge an Östrogen und Progesteron im höheren Alter das Kollagen umformt, wodurch die Gewebesteifigkeit reduziert wird. Die Sakrokolpopexie ist eine offene oder laparoskopische Operation, die mit prothetischen Netzimplantaten durchgeführt wird, um laxe Bänder zu ersetzen. Y-förmige Netzmodelle (DynaMesh, Gynemesh und Ultrapro) werden in einem 3D-Modell des weiblichen Beckenbodens im extraperitonealen Raum vom Vaginalstumpf bis zum Promontorium implantiert. Numerische Simulationen werden während des Valsalva-Manövers mit geschwächtem Gewebe durchgeführt, das durch eine reduzierte Gewebesteifigkeit modelliert wird. Die Gewebe werden als inkompressible, isotrop hyperelastische Materialien modelliert, während die Netze entweder als orthotrope linear elastische oder als isotrope hyperlastische Materialien modelliert werden. Die Positionen des Vaginalstumpfs, der Blase und der Harnröhrenachse werden anhand der Pubococcygeallinie aus der Ruhelage, für den Prolaps und nach der Reparatur unter Verwendung der drei Netze berechnet. Aufgrund der Netzmechanik und der Netzporenverformung bietet das DynaMesh mit regelmäßigen rechteckigen Netzporen eine bessere mechanische Unterstützung und eine Neupositionierung des Scheidengewölbes, der Blase und der Urethraachse als Gynemesh und Ultrapro mit unregelmäßigen hexagonalen Netzporen. Y1 - 2018 U6 - http://dx.doi.org/10.1515/teme-2017-0115 SN - 2196-7113 VL - 85 IS - 5 SP - 331 EP - 342 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Bhattarai, Aroj A1 - May, Charlotte Anabell A1 - Staat, Manfred A1 - Kowalczyk, Wojciech A1 - Tran, Thanh Ngoc T1 - Layer-specific damage modeling of porcine large intestine under biaxial tension JF - Bioengineering N2 - The mechanical behavior of the large intestine beyond the ultimate stress has never been investigated. Stretching beyond the ultimate stress may drastically impair the tissue microstructure, which consequently weakens its healthy state functions of absorption, temporary storage, and transportation for defecation. Due to closely similar microstructure and function with humans, biaxial tensile experiments on the porcine large intestine have been performed in this study. In this paper, we report hyperelastic characterization of the large intestine based on experiments in 102 specimens. We also report the theoretical analysis of the experimental results, including an exponential damage evolution function. The fracture energies and the threshold stresses are set as damage material parameters for the longitudinal muscular, the circumferential muscular and the submucosal collagenous layers. A biaxial tensile simulation of a linear brick element has been performed to validate the applicability of the estimated material parameters. The model successfully simulates the biomechanical response of the large intestine under physiological and non-physiological loads. KW - biaxial tensile experiment KW - anisotropy KW - hyperelastic KW - constitutive modeling KW - damage Y1 - 2022 U6 - http://dx.doi.org/10.3390/bioengineering9100528 SN - 2306-5354 N1 - Der Artikel gehört zum Sonderheft "Computational Biomechanics" VL - 9 IS - 10, Early Access SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bhattarai, Aroj A1 - Staat, Manfred T1 - Modelling of Soft Connective Tissues to Investigate Female Pelvic Floor Dysfunctions JF - Computational and Mathematical Methods in Medicine N2 - After menopause, decreased levels of estrogen and progesterone remodel the collagen of the soft tissues thereby reducing their stiffness. Stress urinary incontinence is associated with involuntary urine leakage due to pathological movement of the pelvic organs resulting from lax suspension system, fasciae, and ligaments. This study compares the changes in the orientation and position of the female pelvic organs due to weakened fasciae, ligaments, and their combined laxity. A mixture theory weighted by respective volume fraction of elastin-collagen fibre compound (5%), adipose tissue (85%), and smooth muscle (5%) is adopted to characterize the mechanical behaviour of the fascia. The load carrying response (other than the functional response to the pelvic organs) of each fascia component, pelvic organs, muscles, and ligaments are assumed to be isotropic, hyperelastic, and incompressible. Finite element simulations are conducted during Valsalva manoeuvre with weakened tissues modelled by reduced tissue stiffness. A significant dislocation of the urethrovesical junction is observed due to weakness of the fascia (13.89 mm) compared to the ligaments (5.47 mm). The dynamics of the pelvic floor observed in this study during Valsalva manoeuvre is associated with urethral-bladder hypermobility, greater levator plate angulation, and positive Q-tip test which are observed in incontinent females. Y1 - 2018 U6 - http://dx.doi.org/10.1155/2018/9518076 SN - 1748-6718 VL - 2018 IS - Article ID 9518076 SP - 1 EP - 16 PB - Hindawi CY - New York, NY 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 - Bhattarai, Aroj A1 - Staat, Manfred T1 - A computational study of organ relocation after laparoscopic pectopexy to repair posthysterectomy vaginal vault prolapse JF - Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization Y1 - 2019 U6 - http://dx.doi.org/10.1080/21681163.2019.1670095 SN - 2168-1171 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Bialonski, Stephan A1 - Allefeld, C. A1 - Wellmer, J. A1 - Elger, C. A1 - Lehnertz, K. T1 - An approach to identify synchronization clusters within the epileptic network JF - Klinische Neurophysiologie Y1 - 2008 U6 - http://dx.doi.org/10.1055/s-2008-1072881 VL - 39 IS - 1 SP - A79 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Ansmann, Gerrit A1 - Kantz, Holger T1 - Data-driven prediction and prevention of extreme events in a spatially extended excitable system JF - Physical Review E Y1 - 2015 U6 - http://dx.doi.org/10.1103/PhysRevE.92.042910 SN - 2470-0053 VL - 92 IS - 4 SP - 042910 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Caron, David A. A1 - Schloen, Julia A1 - Feudel, Ulrike A1 - Kantz, Holger A1 - Moorthi, Stefanie D. T1 - Phytoplankton dynamics in the Southern California Bight indicate a complex mixture of transport and biology JF - Journal of Plankton Research N2 - The stimulation and dominance of potentially harmful phytoplankton taxa at a given locale and time are determined by local environmental conditions as well as by transport to or from neighboring regions. The present study investigated the occurrence of common harmful algal bloom (HAB) taxa within the Southern California Bight, using cross-correlation functions to determine potential dependencies between HAB taxa and environmental factors, and potential links to algal transport via local hydrography and currents. A simulation study, in which Lagrangian particles were released, was used to assess travel times due to advection by prevailing ocean currents in the bight. Our results indicate that transport of some taxa may be an important mechanism for the expansion of their distributions into other regions, which was supported by mean travel times derived from our simulation study and other literature on ocean currents in the Southern California Bight. In other cases, however, phytoplankton dynamics were rather linked to local environmental conditions, including coastal upwelling events. Overall, our study shows that complex current patterns in the Southern California Bight may contribute significantly to the formation and expansion of HABs in addition to local environmental factors determining the spatiotemporal dynamics of phytoplankton blooms. Y1 - 2016 U6 - http://dx.doi.org/10.1093/plankt/fbv122 SN - 1464-3774 VL - 38 IS - 4 SP - 1077 EP - 1091 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Bialonski, Stephan A1 - Horstmann, Marie-Therese A1 - Lehnertz, Klaus T1 - From brain to earth and climate systems: Small-world interaction networks or not? JF - Chaos: An Interdisciplinary Journal of Nonlinear Science N2 - We consider recent reports on small-world topologies of interaction networks derived from the dynamics of spatially extended systems that are investigated in diverse scientific fields such as neurosciences, geophysics, or meteorology. With numerical simulations that mimic typical experimental situations, we have identified an important constraint when characterizing such networks: indications of a small-world topology can be expected solely due to the spatial sampling of the system along with the commonly used time series analysis based approaches to network characterization. Y1 - 2010 U6 - http://dx.doi.org/10.1063/1.3360561 SN - 1089-7682 VL - 20 IS - 1 PB - AIP Publishing CY - Melville, NY ER - TY - JOUR A1 - Bialonski, Stephan A1 - Lehnertz, Klaus T1 - Assortative mixing in functional brain networks during epileptic seizures JF - Chaos: An Interdisciplinary Journal of Nonlinear Science Y1 - 2013 U6 - http://dx.doi.org/10.1063/1.4821915 VL - 23 IS - 3 SP - 033139 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Lehnertz, Klaus T1 - Identifying phase synchronization clusters in spatially extended dynamical systems JF - Physical Review E Y1 - 2006 U6 - http://dx.doi.org/10.1103/PhysRevE.74.051909 SN - 2470-0053 VL - 74 IS - 5 SP - 051909 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Schindler, K. A1 - Elger, C. E. A1 - Lehnertz, Klaus T1 - Lateralized characteristics of the evolution of EEG correlation during focal onset seizures: a mechanism to prevent secondary generalization? JF - Epilepsia N2 - Rationale: Previous studies [Topolnik et al., Cereb Cortex 2003; 13: 883; Schindler et al., Brain 2007; 130: 65] indicate that the termination of focal onset seizures may be causally related to an increase of global neuronal correlation during the second half of the seizures. This increase was observed to occur earlier in complex partial seizures than in secondarily generalized seizures. We here address the question whether such an increase of neuronal correlation prior to seizure end is indeed a global phenomenon, involving both hemispheres or whether there are side-specific differences. Methods: We analyzed 20 focal onset seizures (10 complex partial, 10 secondarily generalized seizures) recorded in 13 patients who underwent presurgical evaluation of focal epilepsies of different origin. EEG was recorded intracranially from bilaterally implanted subdural strip and intrahippocampal depth electrodes. Utilizing a moving window approach, we investigated the evolution of the maximum cross correlation for all channel combinations during seizures. For each moving window the mean value of the maximum cross correlation (MCC) between all electrode contacts was computed separately for each hemisphere. After normalization of seizure durations, MCC values of the ipsi- and contralateral hemisphere for all seizures were determined. Results: We observed that the MCC of the contralateral hemisphere in complex partial seizures increased during the first half of the seizure, whereas, for the same time interval, the MCC of the ipsilateral hemisphere even declined below the level of the pre-seizure period. In contrast, no significant differences between both hemispheres could be observed for secondarily generalized seizures where both hemispheres showed a simultaneous increase of MCC during the second half of the seizures. The level of MCC for the contralateral hemisphere was higher for complex partial seizures than for secondarily generalized seizures during the first half of the seizure. Conclusions: Our findings indicate that there are indeed lateralized differences in the evolution of global neuronal correlation during complex partial and secondarily generalized seizures. The observed contralateral increase of neuronal correlation during complex partial seizures might indicate an emerging self-organizing mechanism for preventing the spread of seizure activity. Y1 - 2008 SN - 0013-9580 VL - 49 SP - 11 EP - 11 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Wellmer, Jörg A1 - Elger, Christian E. A1 - Lehnertz, Klaus T1 - Interictal focus localization in neocortical lesional epilepsies with synchronization cluster analysis JF - Epilepsia Y1 - 2006 SN - 0013-9580 VL - 47 SP - 36 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Wendler, Martin A1 - Lehnertz, Klaus T1 - Unraveling spurious properties of interaction networks with tailored random networks JF - Plos one N2 - We investigate interaction networks that we derive from multivariate time series with methods frequently employed in diverse scientific fields such as biology, quantitative finance, physics, earth and climate sciences, and the neurosciences. Mimicking experimental situations, we generate time series with finite length and varying frequency content but from independent stochastic processes. Using the correlation coefficient and the maximum cross-correlation, we estimate interdependencies between these time series. With clustering coefficient and average shortest path length, we observe unweighted interaction networks, derived via thresholding the values of interdependence, to possess non-trivial topologies as compared to Erdös-Rényi networks, which would indicate small-world characteristics. These topologies reflect the mostly unavoidable finiteness of the data, which limits the reliability of typically used estimators of signal interdependence. We propose random networks that are tailored to the way interaction networks are derived from empirical data. Through an exemplary investigation of multichannel electroencephalographic recordings of epileptic seizures – known for their complex spatial and temporal dynamics – we show that such random networks help to distinguish network properties of interdependence structures related to seizure dynamics from those spuriously induced by the applied methods of analysis. Y1 - 2011 U6 - http://dx.doi.org/10.1371/journal.pone.0022826 VL - 6 IS - 8 PB - Plos CY - San Francisco ER - TY - JOUR A1 - Birgel, Stefan A1 - Leschinger, Tim A1 - Wegmann, Kilian A1 - Staat, Manfred T1 - Calculation of muscle forces and joint reaction loads in the shoulder area via an OpenSim based computer model JF - tm - Technisches Messen N2 - Using the OpenSim software and verified anatomical data, a computer model for the calculation of biomechanical parameters is developed and used to determine the effect of a reattachment of the Supraspinatus muscle with a medial displacement of the muscle attachment point, which may be necessary for a rupture of the supraspinatus tendon. The results include the influence of the operation on basic biomechanical parameters such as the lever arm, as well as the calculated the muscle activations for the supraspinatus and deltoid. In addition, the influence on joint stability is examined by an analysis of the joint reaction force. The study provides a detailed description of the used model, as well as medical findings to a reattachment of the supraspinatus. Mit der Software OpenSim und überprüften anatomischen Daten wird ein Computermodell zur Berechnung von biomechanischen Parametern entwickelt und genutzt, um den Effekt einer Refixierung des Supraspinatusmuskels mit einer medialen Verschiebung des Muskelansatzpunktes zu ermitteln, wie sie unter anderem nach einem Riss der Supraspinatussehne notwendig sein kann. Die Ergebnisse umfassen hierbei den Einfluss der Operation auf grundlegende biomechanische Parameter wie den Hebelarm sowie die berechneten Muskelaktivierungen für den Supraspinatus und Deltoideus. Zusätzlich wird der Einfluss auf die Gelenkstabilität betrachtet und durch eine Analyse der Gelenkreaktionskraft untersucht. Die Studie bietet eine detaillierte Beschreibung des genutzten Modells, sowie medizinische Erkenntnisse zu einer Refixierung des Supraspinatus. Y1 - 2018 U6 - http://dx.doi.org/10.1515/teme-2017-0114 SN - 2196-7113 VL - 85 IS - 5 SP - 321 EP - 330 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Bleilevens, Christian A1 - Hill, Aileen A1 - Grzanna, Tim A1 - Fechter, Tamara A1 - Bohnen, Melanie A1 - Weber, Hans-Joachim A1 - Beckers, Christian A1 - Borosch, Sebastian A1 - Zayat, Rashad A1 - Benstoem, Carin A1 - Rossaint, Rolf A1 - Goetzenich, Andreas T1 - In vitro head-to-head comparison of anticoagulation properties of two heparin brands in a human blood miniature mock loop JF - Interactive cardiovascular and thoracic surgery Y1 - 2019 U6 - http://dx.doi.org/10.1093/icvts/ivy206 SN - 1569-9285 VL - 28 IS - 1 SP - 120 EP - 127 ER - TY - JOUR A1 - Boecker, Henning A1 - Kuwert, Torsten A1 - Langen, Karl-J. A1 - Lange, Herwig W. A1 - Czech, Norbert A1 - Ziemons, Karl A1 - Herzog, Hans A1 - Shikare, Shekar A1 - Weindl, Anton A1 - Feinendegen, Ludwig E. T1 - SPECT with HMPAO compared to PET with FDG in Huntington disease JF - Journal of Computer Assisted Tomography Y1 - 1994 SN - 1532-3145 VL - 18 IS - 4 SP - 542 EP - 548 ER - TY - JOUR A1 - Bogoyavlenskiy, A. P. A1 - Berezin, V. E. A1 - Ogneva, A. V. A1 - Tolmacheva, V. P. A1 - Digel, Ilya A1 - Khudyakova, S. S. T1 - Immunostimulating activity of a saponin-containing extract of Saponaria officinalis JF - Voprosy virusologii Y1 - 1999 SN - 0507-4088 VL - 44 IS - 5 SP - 229 EP - 232 ER - TY - JOUR A1 - Bogoyavlenskiy, A. P. A1 - Digel, Ilya A1 - Berezin, V. E. T1 - Assessment of dot-blot ELISA sensitivity on membrane sorbent using various peroxidase substrates N2 - The sensitivity of the peroxidase reaction in dot-blot ELISA significantly depends on the substrate. The highest sensitivity is observed using benzidine and diamine- phenol combinations as the substrates due to the reaction of the coupled oxidation (NADI) KW - Enzyme-linked immunosorbent assay KW - Peroxidase KW - ELISA KW - phenols KW - naphtols KW - aromatic amines Y1 - 1997 ER - TY - JOUR A1 - Bohrn, U. A1 - Stütz, E. A1 - Fleischer, M. A1 - Schöning, Michael Josef T1 - Real-time detection of CO by eukaryotic cells JF - Procedia Engineering. 5 (2010) Y1 - 2010 SN - 1877-7058 N1 - Eurosensor XXIV Conference SP - 17 EP - 20 ER - TY - JOUR A1 - Bohrn, U. A1 - Stütz, E. A1 - Fuchs, K. A1 - Fleischer, M. A1 - Schöning, Michael Josef A1 - Wagner, P. T1 - Air Quality Monitoring using a Whole-Cell based Sensor System JF - Procedia Engineering. 25 (2011) Y1 - 2011 SN - 1877-7058 N1 - EurosensorsXXV ; Proc. Eurosensors XXV, September 4-7, 2011, Athens, Greece SP - 1421 EP - 1424 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, U. A1 - Stütz, E. A1 - Fuchs, K. A1 - Fleischer, M. A1 - Schöning, Michael Josef A1 - Wagner, P. T1 - Monitoring of irritant gas using a whole-cell-based sensor system JF - Sensors and Actuators B: Chemical N2 - Cell-based sensors for the detection of gases have long been underrepresented, due to the cellular requirement of being cultured in a liquid environment. In this work we established a cell-based gas biosensor for the detection of toxic substances in air, by adapting a commercial sensor chip (Bionas®), previously used for the measurement of pollutants in liquids. Cells of the respiratory tract (A549, RPMI 2650, V79), which survive at a gas phase in a natural context, are used as biological receptors. The physiological cell parameters acidification, respiration and morphology are continuously monitored in parallel. Ammonia was used as a highly water-soluble model gas to test the feasibility of the sensor system. Infrared measurements confirmed the sufficiency of the medium draining method. This sensor system provides a basis for many sensor applications such as environmental monitoring, building technology and public security. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.snb.2012.05.088 SN - 0925-4005 VL - 175 SP - 208 EP - 217 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Trattner, Barbara A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Stütz, Evamaria A1 - Schmitt-Landsiedel, Doris A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment JF - Sensors and actuators. B: Chemical Y1 - 2013 SN - 1873-3077 (E-Journal); 0925-4005 (Print) VL - Vol. 182 SP - 58 EP - 65 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Stütz, Evamaria A1 - Fleischer, Maximilian A1 - Schöning, Michael Josef A1 - Wagner, Patrick T1 - Eukaryotic cell lines as a sensitive layer for direct monitoring of carbon monoxide JF - Physica status solidi (a) : applications and material science. 208 (2011), H. 6 Y1 - 2011 SN - 1862-6319 SP - 1345 EP - 1350 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Stütz, Evamaria A1 - Fleischer, Maximilian A1 - Schöning, Michael Josef A1 - Wagner, Patrick T1 - Using a cell-based gas biosensor for investigation of adverse effects of acetone vapors in vitro JF - Biosensors and Bioelectronics. 40 (2013), H. 1 Y1 - 2013 SN - 0956-5663 SP - 393 EP - 400 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bornheim, Tobias A1 - Grieger, Niklas A1 - Blaneck, Patrick Gustav A1 - Bialonski, Stephan T1 - Speaker Attribution in German Parliamentary Debates with QLoRA-adapted Large Language Models JF - Journal for language technology and computational linguistics : JLCL N2 - The growing body of political texts opens up new opportunities for rich insights into political dynamics and ideologies but also increases the workload for manual analysis. Automated speaker attribution, which detects who said what to whom in a speech event and is closely related to semantic role labeling, is an important processing step for computational text analysis. We study the potential of the large language model family Llama 2 to automate speaker attribution in German parliamentary debates from 2017-2021. We fine-tune Llama 2 with QLoRA, an efficient training strategy, and observe our approach to achieve competitive performance in the GermEval 2023 Shared Task On Speaker Attribution in German News Articles and Parliamentary Debates. Our results shed light on the capabilities of large language models in automating speaker attribution, revealing a promising avenue for computational analysis of political discourse and the development of semantic role labeling systems. KW - large language models KW - German KW - speaker attribution KW - semantic role labeling Y1 - 2024 U6 - http://dx.doi.org/10.21248/jlcl.37.2024.244 SN - 2190-6858 VL - 37 IS - 1 PB - Gesellschaft für Sprachtechnologie und Computerlinguistik CY - Regensburg ER - TY - JOUR A1 - Bressel, A. A1 - Schultze, J.W. A1 - Khan, W. A1 - Wolfaardt, G. M. A1 - Rohns, H.-P. A1 - Irmscher, R. A1 - Schöning, Michael Josef T1 - High resolution gravimetric, optical and electrochemical investigations of microbial biofilm formation in aqueous systems JF - Electrochimica Acta. 48 (2003), H. 20-22 Y1 - 2003 SN - 0013-4686 SP - 3363 EP - 3372 ER - TY - JOUR A1 - Breuer, Lars A1 - Mang, Thomas A1 - Schöning, Michael Josef A1 - Thoelen, Ronald A1 - Wagner, Torsten T1 - Investigation of the spatial resolution of a laser-based stimulation process for light-addressable hydrogels with incorporated graphene oxide by means of IR thermography JF - Sensors and Actuators A: Physical Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.sna.2017.11.031 SN - 0924-4247 VL - 268 SP - 126 EP - 132 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Breuer, Lars A1 - Pilas, Johanna A1 - Guthmann, Eric A1 - Schöning, Michael Josef A1 - Thoelen, Ronald A1 - Wagner, Torsten T1 - Towards light-addressable flow control: responsive hydrogels with incorporated graphene oxide as laser-driven actuator structures within microfluidic channels JF - Sensor and Actuators B: Chemical Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.snb.2019.02.086 SN - 0925-4005 VL - 288 SP - 579 EP - 585 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Breuer, Lars A1 - Raue, Markus A1 - Kirschbaum, M. A1 - Mang, Thomas A1 - Schöning, Michael Josef A1 - Thoelen, R. A1 - Wagner, Torsten T1 - Light-controllable polymeric material based on temperature-sensitive hydrogels with incorporated graphene oxide JF - Physica status solidi (a) N2 - Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel films with incorporated graphene oxide (GO) were developed and tested as light-stimulated actuators. GO dispersions were synthesized via Hummers method and characterized toward their optical properties and photothermal energy conversion. The hydrogels were prepared by means of photopolymerization. In addition, the influence of GO within the hydrogel network on the lower critical solution temperature (LCST) was investigated by differential scanning calorimetry (DSC). The optical absorbance and the response to illumination were determined as a function of GO concentration for thin hydrogel films. A proof of principle for the stimulation with light was performed. Y1 - 2015 U6 - http://dx.doi.org/10.1002/pssa.201431944 SN - 1862-6319 VL - 212 IS - 6 SP - 1368 EP - 1374 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Breuer, Lars A1 - Raue, Markus A1 - Strobel, M. A1 - Mang, Thomas A1 - Schöning, Michael Josef A1 - Thoelen, R. A1 - Wagner, Torsten T1 - Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems JF - Physica status solidi (a) N2 - Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium. Y1 - 2016 U6 - http://dx.doi.org/10.1002/pssa.201533056 SN - 1862-6300 VL - 213 IS - 6 SP - 1520 EP - 1525 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Brockhaus, Moritz K. A1 - Behbahani, Mehdi A1 - Muris, Farina A1 - Jansen, Sebastian V. A1 - Schmitz- Rode, Thomas A1 - Steinseifer, Ulrich A1 - Clauser, Johanna C. T1 - In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept JF - Artificial Organs N2 - Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential. Y1 - 2021 U6 - http://dx.doi.org/10.1111/aor.14046 SN - 1525-1594 VL - 45 IS - 12 SP - 1513 EP - 1521 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Bronder, Thomas A1 - Jessing, Max P. A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Detection of PCR-Amplified Tuberculosis DNA Fragments with Polyelectrolyte-Modified Field-Effect Sensors JF - Analytical Chemistry N2 - Field-effect-based electrolyte-insulator-semiconductor (EIS) sensors were modified with a bilayer of positively charged weak polyelectrolyte (poly(allylamine hydrochloride) (PAH)) and probe single-stranded DNA (ssDNA) and are used for the detection of complementary single-stranded target DNA (cDNA) in different test solutions. The sensing mechanism is based on the detection of the intrinsic molecular charge of target cDNA molecules after the hybridization event between cDNA and immobilized probe ssDNA. The test solutions contain synthetic cDNA oligonucleotides (with a sequence of tuberculosis mycobacteria genome) or PCR-amplified DNA (which origins from a template DNA strand that has been extracted from Mycobacterium avium paratuberculosis-spiked human sputum samples), respectively. Sensor responses up to 41 mV have been measured for the test solutions with DNA, while only small signals of ∼5 mV were detected for solutions without DNA. The lower detection limit of the EIS sensors was ∼0.3 nM, and the sensitivity was ∼7.2 mV/decade. Fluorescence experiments using SybrGreen I fluorescence dye support the electrochemical results. Y1 - 2018 U6 - http://dx.doi.org/10.1021/acs.analchem.8b01807 SN - 0003-2700 VL - 90 IS - 12 SP - 7747 EP - 7753 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Jessing, Max P. A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Surface regeneration and reusability of label-free DNA biosensors based on weak polyelectrolyte-modified capacitive field-effect structures JF - Biosensors and Bioelectronics Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.bios.2018.11.019 SN - 0956-5663 VL - 126 SP - 510 EP - 517 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Label-free detection of double-stranded DNA molecules with polyelectrolyte-modified capacitive field-effect sensors T1 - Markierungsfreie Detektion doppelsträngiger DNA Moleküle mit Hilfe von Polyelektrolyt-modifizierten kapazitiven Feldeffekt-Sensoren JF - tm - Technisches Messen N2 - In this study, polyelectrolyte-modified field-effect-based electrolyte-insulator-semiconductor (EIS) devices have been used for the label-free electrical detection of double-stranded deoxyribonucleic acid (dsDNA)molecules. The sensor-chip functionalization with a positively charged polyelectrolyte layer provides the possibility of direct adsorptive binding of negatively charged target DNA oligonucleotides onto theSiO2-chip surface.EIS sensors can be utilized as a tool to detect surface-charge changes; the electrostatic adsorption of oligonucleotides onto the polyelectrolyte layer leads to a measureable surface-potential change. Signals of 39mV have been recorded after the incubation with the oligonucleotide solution. Besides the electrochemical experiments, the successful adsorption of dsDNA onto the polyelectrolyte layer has been verified via fluorescence microscopy. The presented results demonstrate that the signal recording of EISchips, which are modified with a polyelectrolyte layer, canbe used as a favorable approach for a fast, cheap and simple detection method for dsDNA. Y1 - 2017 U6 - http://dx.doi.org/10.1515/teme-2017-0015 VL - 84 IS - 10 SP - 628 EP - 634 PB - De Gruyter CY - Oldenbourg ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Scheja, S. A1 - Wu, Chunsheng A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Electrostatic Detection of Unlabelled Single- and Double-stranded DNA Using Capacitive Field-effect Devices Functionalized with a Positively Charged Polyelectrolyte Layer JF - Procedia Engineering N2 - Capacitive field-effect electrolyte-insulator-semiconductor sensors consisting of an Al-p-Si-SiO2 structure have been used for the electrical detection of unlabelled single- and double-stranded DNA (dsDNA) molecules by their intrinsic charge. A simple functionalization protocol based on the layer-by-layer (LbL) technique was used to prepare a weak polyelectrolyte/probe-DNA bilayer, followed by the hybridization with complementary target DNA molecules. Due to the flat orientation of the LbL-adsorbed DNA molecules, a high sensor signal has been achieved. In addition, direct label-free detection of in-solution hybridized dsDNA molecules has been studied. Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.proeng.2015.08.710 SN - 1877-7058 N1 - Eurosensors 2015 VL - 120 SP - 544 EP - 547 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Scheja, Sabrina A1 - Wu, Chunsheng A1 - Keusgen, Michael A1 - Mewes, Dieter A1 - Schöning, Michael Josef T1 - DNA Immobilization and Hybridization Detection by the Intrinsic Molecular Charge Using Capacitive Field-Effect Sensors Modified with a Charged Weak Polyelectrolyte Layer JF - Applied Materials & Interfaces N2 - Miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge favor the semiconductor field-effect platform as one of the most attractive approaches for the development of label-free DNA chips. In this work, a capacitive field-effect EIS (electrolyte–insulator–semiconductor) sensor covered with a layer-by-layer prepared, positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was used for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization. The negatively charged probe single-stranded DNA (ssDNA) molecules were electrostatically adsorbed onto the positively charged PAH layer, resulting in a preferentially flat orientation of the ssDNA molecules within the Debye length, thus yielding a reduced charge-screening effect and a higher sensor signal. Each sensor-surface modification step (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), reducing an unspecific adsorption by a blocking agent, incubation with noncomplementary DNA (ncDNA) solution) was monitored by means of capacitance–voltage and constant-capacitance measurements. In addition, the surface morphology of the PAH layer was studied by atomic force microscopy and contact-angle measurements. High hybridization signals of 34 and 43 mV were recorded in low-ionic strength solutions of 10 and 1 mM, respectively. In contrast, a small signal of 4 mV was recorded in the case of unspecific adsorption of fully mismatched ncDNA. The density of probe ssDNA and dsDNA molecules as well as the hybridization efficiency was estimated using the experimentally measured DNA immobilization and hybridization signals and a simplified double-layer capacitor model. The results of field-effect experiments were supported by fluorescence measurements, verifying the DNA-immobilization and hybridization event. Y1 - 2015 U6 - http://dx.doi.org/10.1021/acsami.5b05146 VL - 36 IS - 7 SP - 20068 EP - 20075 PB - American Chemical Society CY - Washington, DC ER - TY - JOUR A1 - Bronder, Thomas A1 - Wu, Chunsheng A1 - Poghossian, Arshak A1 - Werner, Frederik A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies JF - Procedia Engineering N2 - Light-addressable potentiometric sensors (LAPS) consisting of a p-Si-SiO2 and p-Si-SiO2-Au structure, respectively, have been tested for a label-free electrical detection of DNA (deoxyribonucleic acid) hybridization. Three different strategies for immobilizing single-stranded probe DNA (ssDNA) molecules on a LAPS surface have been studied and compared: (a) immobilization of thiol-modified ssDNA on the patterned Au surface via gold-thiol bond, (b) covalent immobilization of amino-modified ssDNA onto the SiO2 surface functionalized with 3-aminopropyltriethoxysilane and (c) layer-by-layer adsorption of negatively charged ssDNA on a positively charged weak polyelectrolyte layer of poly(allylamine hydrochloride). KW - LAPS KW - lable-free detection KW - DNA hybridization KW - field-effect sensor Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.proeng.2014.11.647 SN - 1877-7058 N1 - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014> VL - 87 SP - 755 EP - 758 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Buniatyan, V. A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Aroutiounian, V. M. A1 - Schöning, Michael Josef T1 - BaxSr1-x TiO3/pc-Si heterojunction capacitance JF - Armenian journal of physics Y1 - 2013 SN - 1829-1171 VL - 6 IS - 4 SP - 188 EP - 197 PB - National Academy of Sciences of Armenia CY - Yerevan ER - TY - JOUR A1 - Buniatyan, V. A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Aroutiounian, V. M. A1 - Schöning, Michael Josef T1 - BaxSr1-x TiO3/pc-Si heterojunction JF - Armenian journal of physics Y1 - 2013 SN - 1829-1171 VL - 6 IS - 4 SP - 177 EP - 187 PB - National Academy of Sciences of Armenia CY - Yerevan ER - TY - JOUR A1 - Buniatyan, V. V. A1 - Matirosyan, N. W. A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef A1 - Poghossian, Arshak A1 - Schubert, J. A1 - Khachatryan, V. R. A1 - Soukiassyan, G. R. T1 - (Ba,Sr)TiO3 based electrolyte-insulator-semiconductor pHsensors: comparitive study JF - Semiconductor micro- and nanoelectronics : Proceedings of the Seventh International Conference , Tsakhcadzor, Armenia July 3-5 2009 Y1 - 2009 SP - 71 EP - 74 ER - TY - JOUR A1 - Buniatyan, Vahe V. A1 - Abouzar, Maryam H. A1 - Martirosyan, Norayr W. A1 - Schubert, Jürgen A1 - Gevorgian, Spartak A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - pH-sensitive properties of barium strontium titanate (BST) thin films prepared by pulsed laser deposition technique JF - Physica Status Solidi (A). 207 (2010), H. 4 Y1 - 2010 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 SP - 824 EP - 830 ER - TY - JOUR A1 - Buniatyan, Vahe V. A1 - Matirosyan, N. A1 - Abouzar, Maryam H. A1 - Schubert, J. A1 - Zander, W. A1 - Gevorgian, S. A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Capacitive field-effect pH sensor based on an electrolyte-ferroelectric-insulator-semiconductor structure JF - SENSOR 2009 : : 14th International Conference on Sensors, Technologies, Electronics and Applications; Nürnberg, Germany, 26 - 28 May 2009; proceedings; [part of] Sensor + Test Conference 2009 / AMA, Fachverband für Sensorik e.V Y1 - 2009 SN - 9783981099355 N1 - AMA, Fachverband für Sensorik ; Sensor International Conference ; (14 : ; 2009.05.26-28 : ; Nürnberg) SP - 317 EP - 322 PB - AMA Service CY - Wunstorf ER - TY - JOUR A1 - Burkhardt, Klaus A1 - Schwarz, Sonja A1 - Pan, Chengrui A1 - Stelter, Felix A1 - Kotliar, Konstantin A1 - Eynatten, Maxilian von A1 - Sollinger, Daniel A1 - Lanzl, Ines A1 - Heemann, Uwe A1 - Baumann, Marcus T1 - Myeloid-related protein 8/14 complex describes microcirculatory alterations in patients with type 2 diabetes and nephropathy JF - Cardiovascular Diabetology Y1 - 2009 SN - 1475-2840 VL - 8 IS - 10 SP - 1 EP - 8 PB - - ER - TY - JOUR A1 - Buß, G. A1 - Ecken, H. A1 - Winkels, S. A1 - Schöning, Michael Josef A1 - Lüth, H. A1 - Schultze, J. W. T1 - Galvanic modifications of multifunctional silicon-based microelectrode arrays JF - Electrochemical technology applications in electronics : proceedings of the third international symposium / [International Symposium on Electrochemical Technology Applications in Electronics, held during October 20 - 22, 1999, Honolulu, Hawaii]. Electrodeposition Division. Ed.: L. T. Romankiw Y1 - 2000 SN - 1566772575 N1 - International Symposium on Electrochemical Technology Applications in Electronics ; (3, 1999, Honolulu, Hawaii) ; Proceedings volume // Electrochemical Society ; 99-34 SP - 209 EP - 215 PB - Electrochemical Society CY - Pennington, NJ ER - TY - JOUR A1 - Bäcker, Matthias A1 - Beging, Stefan A1 - Biselli, Manfred A1 - Poghossian, Arshak A1 - Wang, J. A1 - Zang, Werner A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Concept for a solid-state multi-parameter sensor system for cell-culture monitoring JF - Electrochimica Acta. 54 (2009), H. 25 Sp. Iss. SI Y1 - 2009 SN - 0013-4686 SP - 6107 EP - 6112 PB - Elsevier CY - Amsterdam ER -