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 - 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 - 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 - 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, M. A1 - Bischof, F. A1 - Wolf, G. E. T1 - Kranken Herzen helfen - Ingenieure und Informatiker entwickeln gemeinsam eine Miniaturblutpumpe / Behbahani, M. ; Behr, M. ; Bischof, F. ; Wolf, G. E. JF - RWTH-Themen (2007) Y1 - 2007 SN - 0179-079X SP - 44 EP - 46 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 - CHAP A1 - Behbahani, Mehdi T1 - An Experimental Study of Thrombocyte Reactions in Response to Biomaterial Surfaces and Varying Shear Stress T2 - Proceedings of the International Conference on Biomedical Engineering and Systems Prague, Czech Republic, August 14-15, 2014 Y1 - 2014 SP - Paper 125 ER - TY - THES A1 - Behbahani, Mehdi T1 - Modeling and Simulation of Shear-Dependent Platelet Reactions in Blood Vessels and Blood-Contacting Medical Devices Y1 - 2011 SN - 978-3-8439-0134-5 PB - Verlag Dr. Hut CY - München 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 - 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 - CHAP A1 - Bayer, Robin A1 - Hescheler, Jürgen A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül ED - Staat, Manfred ED - Erni, Daniel T1 - Treating arterial hypertension in a cell culture well T2 - 3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH AachenW N2 - Hypertension describes the pathological increase of blood pressure, which is most commonly associated with the increase of vascular wall stiffness [1]. Referring to the “Deutsche Bluthochdruck Liga” this pathology shows a growing trend in our aging society. In order to find novel pharmacological and probably personalized treatments, we want to present a functional approach to study biomechanical properties of a human aortic vascular model. In this method review we will give an overview of recent studies which were carried out with the CellDrum technology [2] and underline the added value to already existing standard procedures known from the field of physiology. Herein described CellDrum technology is a system to measure functional mechanical properties of cell monolayers and thin tissue constructs in-vitro. Additionally, the CellDrum enables to elucidate the mechanical response of cells to pharmacological drugs, toxins and vasoactive agents. Due to its highly flexible polymer support, cells can also be mechanically stimulated by steady and cyclic biaxial stretching. Y1 - 2019 SN - 978-3-940402-22-6 U6 - http://dx.doi.org/10.17185/duepublico/48750 SP - 5 EP - 6 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - THES A1 - Bayer, Robin T1 - Development of a novel in-vitro vascular model for determination of physiological and pathophysiological mechanobiology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:38-362212 N1 - Dissertation, Universität zu Köln, 2021 PB - Universität zu Köln CY - Köln 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 - 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 - 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 - CHAP A1 - Bassam, Rasha A1 - Digel, Ilya A1 - Artmann, Gerhard T1 - Effect of nitric oxide on protein thermal stability : [abstract] N2 - As a deduction from these results, we can conclude that proteins mainly in vitro, denaturate totally at a temperature between 57°C -62°C, and they also affected by NO and different ions types. In which mainly, NO cause earlier protein denaturation, which means that, NO has a destabilizing effect on proteins, and also different ions will alter the protein denaturation in which, some ions will cause earlier protein denaturation while others not. KW - Stickstoffmonoxid KW - Proteine KW - Hämoglobin KW - nitric oxide gas KW - protein KW - hemoglobin Y1 - 2009 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 - THES A1 - Bassam Abduljabbar, Rasha T1 - Physikalisch-chemische Steuerung der Proteinstabilität in biologischen Systemen T1 - Physico-chemical management of protein stability in biological systems Y1 - 2015 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 - 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 -