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 - Preiß, C. A1 - Linder, Peter A1 - Wendt, K. A1 - Krystek, M. A1 - Digel, Ilya A1 - Gossmann, Matthias A1 - Temiz Artmann, Aysegül A1 - Porst, Dariusz A1 - Kayser, Peter A1 - Bassam, Rasha A1 - Artmann, Gerhard T1 - Engineering technology for plant physiology and plant stress research N2 - Plant physiology and plant stress: Plant physiology will be much more important for human mankind because of yield and cultivation limits of crops determined by their resistance to stress. To assess and counteract various stress factors it is necessary to conduct plant research to gain information and results on plant physiology. KW - Pflanzenphysiologie KW - Pflanzenstress KW - Pflanzenscanner KW - plant stress KW - plant scanner Y1 - 2011 ER - TY - JOUR A1 - Seifarth, Volker A1 - Schehl, D. A1 - Linder, Peter A1 - Gossmann, Matthias A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Porst, Dariusz A1 - Preiß, C. A1 - Kayser, Peter A1 - Pack, O. A1 - Temiz Artmann, Aysegül T1 - Ureplace: development of a bioreactor for in vitro culturing of cell seeded tubular vessels on collagen scaffolds N2 - The demand of replacements for inoperable organs exceeds the amount of available organ transplants. Therefore, tissue engineering developed as a multidisciplinary field of research for autologous in-vitro organs. Such three dimensional tissue constructs request the application of a bioreactor. The UREPLACE bioreactor is used to grow cells on tubular collagen scaffolds OPTIMAIX Sponge 1 with a maximal length of 7 cm, in order to culture in vitro an adequate ureter replacement. With a rotating unit, (urothelial) cells can be placed homogeneously on the inner scaffold surface. Furthermore, a stimulation is combined with this bioreactor resulting in an orientation of muscle cells. These culturing methods request a precise control of several parameters and actuators. A combination of a LabBox and the suitable software LabVision is used to set and conduct parameters like rotation angles, velocities, pressures and other important cell culture values. The bioreactor was tested waterproof successfully. Furthermore, the temperature controlling was adjusted to 37 °C and the CO2 - concentration regulated to 5 %. Additionally, the pH step responses of several substances showed a perfect functioning of the designed flow chamber. All used software was tested and remained stable for several days. KW - Tissue Engineering KW - Bioreaktor KW - Organkultur KW - Harnleiter Y1 - 2011 ER - TY - JOUR A1 - Zhubanova, Azhar A. A1 - Aknazarov, S. K. A1 - Mansurov, Zulkhair A1 - Digel, Ilya A1 - Kozhalakova, A. A. A1 - Akimbekov, Nuraly Shardarbekovich A1 - O'Heras, Carlos A1 - Tazhibayeva, S. A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Adsorption of bacterial Lipopolysaccharides and blood plasma proteins on modified carbonized materials N2 - Bacterial lipopolysaccharides (endotoxins) show strong biological effects at very low concentrations in human beings and many animals when entering the blood stream. These include affecting structure and function of organs and cells, changing metabolic functions, raising body temperature, triggering the coagulation cascade, modifying hemodynamics and causing septic shock. Because of this toxicity, the removal of even minute amounts is essential for safe parenteral administration of drugs and also for septic shock patients' care. The absence of a general method for endotoxin removal from liquid interfaces urgently requires finding new methods and materials to overcome this gap. Nanostructured carbonized plant parts is a promising material that showed good adsorption properties due to its vast pore network and high surface area. The aim of this study was comparative measurement of endotoxin- and blood proteins-related adsorption rate and adsorption capacity for different carboneous materials produced at different temperatures and under different surface modifications. As a main surface modificator, positively cbarged polymer, polyethileneimine (PEl) was used. Activated carbon materials showed good adsorption properties for LPS and some proteins used in the experiments. During the batch experiments, several techniques (dust removal, autoclaving) were used and optimized for improving the material's adsorption behavior. Also, with the results obtained it was possible to differentiate the materials according to their adsorption capacity and kinetic characteristics. Modification of the surface apparently has not affected hemoglobin binding to the adsorbent's surface. Obtained adsorption isotherms can be used as a powerful tool for designing of future column-based setups for blood purification from LPS, which is especially important for septic shock treatment. KW - Kohlenstofffaser KW - Lipopolysaccharide KW - nanostrukturierte carbonisierte Pflanzenteile KW - lipopolysaccharides KW - nanostructured carbonized plant parts Y1 - 2010 ER - TY - JOUR A1 - Zhubanova, Azhar A. A1 - Digel, Ilya A1 - Nojima, H. A1 - Artmann, Gerhard T1 - The use of bactericidal effects of cluster ions generated by plasma in medical biotechnology N2 - The most of conventional methods of air purification use the power of a fan to draw in air and pass it through a filter. The problem of bacterial contamination of inner parts of such a type of air conditioners in some cases draws attention towards alternative air-cleaning systems. Some manufacturers offer to use the ozone's bactericidal and deodorizing effects, but the wide spreading of such systems is restricted by the fact that toxic effects of ozone in respect of human beings are well known. In 2000 Sharp Inc. introduced "Plasma Cluster Ions (PCI)" air purification technology, which uses plasma discharge to generate cluster ions (I 0-14 ). This technology has been developed for those customers that are conscious about health and hygiene. In our experiments, we focused on some principal aspects of plasma-generated ions application - time-dependency and irreversibility of bactericidal action, spatial and kinetic characteristics of emitted cluster particles, their chemical targets in the microbial cells. KW - Clusterion KW - Raumluft KW - Luftreiniger KW - Plasmacluster ion technology KW - Air purification Y1 - 2007 ER - TY - JOUR A1 - Akimbekov, Nuraly Shardarbekovich A1 - Mansurov, Zulkhair A1 - Jandosov, J. A1 - Digel, Ilya A1 - Gossmann, Matthias A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül A1 - Zhubanova, Azhar A. T1 - Wound healing activity of carbonized rice husk N2 - The carbonized rice husk (CRH) was evaluated for its wound healing activity in rats using excision models. In this study, the influences of CRH on wound healing in rat skin in vivo and cellular behavior of human dermal fibroblasts in vitro were investigated. The obtained results showed that the CRH treatment promoted wound epithelization in rats and exhibited moderate inhibition of cell proliferation in vitro. CRH with lanolin oil treated wounds were found to epithelize faster as compared to controls. KW - Wundheilung KW - Epithel KW - Fibroblast KW - carbonized rice husk KW - wound healing KW - epithelization KW - human dermal fibroblasts Y1 - 2013 PB - Trans Tech Publications, Switzerland CY - Bäch 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 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels N2 - Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data. KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohr KW - Rohrbruch KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohrbruch KW - Fehlerstellen KW - pipes KW - vessels KW - load limit KW - burst tests KW - burst pressure KW - flaw Y1 - 2004 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels N2 - Limit loads can be calculated with the finite element method (FEM) for any component, defect geometry, and loading. FEM suggests that published long crack limit formulae for axial defects under-estimate the burst pressure for internal surface defects in thick pipes while limit loads are not conservative for deep cracks and for pressure loaded crack-faces. Very deep cracks have a residual strength, which is modelled by a global collapse load. These observations are combined to derive new analytical local and global collapse loads. The global collapse loads are close to FEM limit analyses for all crack dimensions. KW - Finite-Elemente-Methode KW - Grenzwertberechnung KW - Axialbelastung KW - FEM KW - Grenzwertberechnung KW - Axialbelastung KW - Traglastanalyse KW - Limit analysis KW - Global and local collapse KW - Axially cracked pipe KW - Pressure loaded crack-face Y1 - 2005 ER - TY - JOUR A1 - Staat, Manfred T1 - Direct finite element route for design-by-analysis of pressure components N2 - In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion. KW - Einspielen KW - Plastizität KW - Deformation KW - Analytischer Zulaessigkeitsnachweis KW - Einspiel-Analyse KW - fortschreitende plastische Deformation KW - alternierend Verformbarkeit KW - Einspiel-Kriterium KW - Design-by-analysis KW - Shakedown analysis KW - Progressive plastic deformation KW - Alternating plasticity KW - Shakedown criterion Y1 - 2005 ER -