TY - JOUR A1 - Kappler-Tanudyaya, Nathalie A1 - Schmitt, Heike A1 - Tippkötter, Nils A1 - Meyer, Lina A1 - Lenzen, Sigurd A1 - Ulber, Roland T1 - Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose JF - Biotechnology Journal N2 - Mannoheptulose is a seven-carbon sugar. It is an inhibitor of glucose-induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently. Y1 - 2007 U6 - https://doi.org/10.1002/biot.200700004 SN - 1860-7314 VL - 2 IS - 6 SP - 692 EP - 699 ER - TY - JOUR A1 - Tippkötter, Nils A1 - Deterding, A. A1 - Ulber, Roland T1 - Determination of acetic acid in fermentation broth by gas-diffusion technique JF - Engineering in Life Sciences N2 - Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5–5.0 g/L acetic acid with a relative standard deviation of <5 % was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents. Y1 - 2008 U6 - https://doi.org/10.1002/elsc.200820227 VL - 8 IS - 1, Special Issue: Technical Systems for the Use in Life Sciences SP - 62 EP - 67 ER - TY - CHAP A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Huynh A1 - Staat, Manfred T1 - Physical response of hyperelastic models for composite materials and soft tissues T2 - Advances in Composite Material Y1 - 2017 SN - 978-1-61896-300-0 (Hardcover), 978-1-61896-299-7 (Paperback) N1 - Chapter 5 PB - Scientific Research Publishing CY - Wuhan ER - TY - JOUR A1 - Tippkötter, Nils A1 - Roikaew, Wipa A1 - Ulber, Roland A1 - Hoffmann, Alexander A1 - Denzler, Hans-Jörg A1 - Buchholz, Heinrich T1 - Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food JF - Biotechnology Progress N2 - Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L-1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed. Y1 - 2010 U6 - https://doi.org/10.1002/btpr.384 SN - 8756-7938 VL - 26 IS - 3 SP - 756 EP - 762 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Poth, Sebastian A1 - Monzon, Magaly A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Lignocellulosic biorefinery: Process integration of hydrolysis and fermentation (SSF process) JF - Holzforschung N2 - The aim of the present work is the process integration and the optimization of the enzymatic hydrolysis of wood and the following fermentation of the products to ethanol. The substrate is a fiber fraction obtained by organosolv pre-treatment of beech wood. For the ethanol production, a co-fermentation by two different yeasts (Saccharomyces cerevisiae and Pachysolen tannophilus) was carried out to convert glucose as well as xylose. Two approaches has been followed: 1. A two step process, in which the hydrolysis of the fiber fraction and the fermentation to product are separated from each other. 2. A process, in which the hydrolysis and the fermentation are carried out in one single process step as simultaneous saccharification and fermentation (SSF). Following the first approach, a yield of about 0.15 g ethanol per gram substrate can be reached. Based on the SSF, one process step can be saved, and additionally, the gained yield can be raised up to 0.3 g ethanol per gram substrate. Y1 - 2011 N1 - 11th EWLP, Hamburg, Germany, August 16–19, 2010 VL - 65 IS - 5 SP - 633 EP - 637 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Sieker, Tim A1 - Neuner, Andreas A1 - Dimitrova, Darina A1 - Tippkötter, Nils A1 - Muffler, Kai A1 - Bart, Hans-Jörg A1 - Heinzle, Elmar A1 - Ulber, Roland T1 - Ethanol production from grass silage by simultaneous pretreatment, saccharification and fermentation: First steps in the process development JF - Engineering in Life Sciences N2 - Grass silage provides a great potential as renewable feedstock. Two fractions of the grass silage, a press juice and the fiber fraction, were evaluated for their possible use for bioethanol production. Direct production of ethanol from press juice is not possible due to high concentrations of organic acids. For the fiber fraction, alkaline peroxide or enzymatic pretreatment was used, which removes the phenolic acids in the cell wall. In this study, we demonstrate the possibility to integrate the enzymatic pretreatment with a simultaneous saccharification and fermentation to achieve ethanol production from grass silage in a one-process step. Achieved yields were about 53 g ethanol per kg silage with the alkaline peroxide pretreatment and 91 g/kg with the enzymatic pretreatment at concentrations of 8.5 and 14.6 g/L, respectively. Furthermore, it was shown that additional supplementation of the fermentation medium with vitamins, trace elements and nutrient salts is not necessary when the press juice is directly used in the fermentation step. Y1 - 2011 U6 - https://doi.org/10.1002/elsc.201000160 N1 - Special Issue "Bioprocess‐oriented plant design" VL - 11 IS - 4 SP - 436 EP - 442 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Al-Kaidy, Huschyar A1 - Wollny, Steffen A1 - Ulber, Roland T1 - Functionalized magnetizable particles for downstream processing in single-use systems JF - Chemie Ingenieur Technik N2 - Biotechnological downstream processing is usually an elaborate procedure, requiring a multitude of unit operations to isolate the target component. Besides the disadvantageous space-time yield, the risks of cross-contaminations and product loss grow fast with the complexity of the isolation procedure. A significant reduction of unit operations can be achieved by application of magnetic particles, especially if these are functionalized with affinity ligands. As magnetic susceptible materials are highly uncommon in biotechnological processes, target binding and selective separation of such particles from fermentation or reactions broths can be done in a single step. Since the magnetizable particles can be produced from iron salts and low priced polymers, a single-use implementation of these systems is highly conceivable. In this article, the principles of magnetizable particles, their synthesis and functionalization are explained. Furthermore, applications in the area of reaction engineering, microfluidics and downstream processing are discussed focusing on established single-use technologies and development potential. Y1 - 2013 U6 - https://doi.org/10.1002/cite.201200130 VL - 85 IS - 1-2: Special Issue: Single-Use Technology SP - 76 EP - 86 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Thiel, Alexander A1 - Tippkötter, Nils A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - New zeolite adsorbents for downstream processing of polyphenols from renewable resources JF - Engineering in Life Sciences N2 - Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources. Y1 - 2013 U6 - https://doi.org/10.1002/elsc.201200188 VL - 13 IS - 3 SP - 239 EP - 246 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Wollny, Steffen A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - Recycling of spent oil bleaching earth as source of glycerol for the anaerobic production of acetone, butanol, and ethanol with Clostridium diolis and lipolytic Clostridium lundense JF - Engineering in Life Sciences N2 - A major part of edible oil is subjected to bleaching procedures, primarily with minerals applied as adsorbers. Their recycling is currently done either by regaining the oil via organic solvent extraction or by using the spent bleaching earth (SBE) as additive for animal feed, etc. As a new method, the reutilization of the by-product SBE for the microbiologic formation of acetone, butanol, and ethanol (ABE) is presented as proof-of-concept. The SBE was taken from a palm oil cleaning process. The recycling concept is based on the application of lipolytic clostridia strains. Due to considerably long fermentation times, co-fermentation with Candida rugosa and enzymatic hydrolyses of the bound oil with a subsequent clostridia fermentation are shown as alternative routes. Anaerobic fermentations under comparison of different clostridia strains were performed with glycerol media, enzymatically hydrolyzed palm oil and SBE. Solutes, side product compositions and productivities were quantified via HPLC. A successful production of ABE solutes from SBE has been done with a yield of 0.15 g butanol per gram of bound glycerol. Thus, the biotechnological recycling of the waste stream is possible in principle. Inhibition of the substrate suspension has been observed. A chromatographic ion-exchange of substrates increased the biomass concentration. Y1 - 2014 U6 - https://doi.org/10.1002/elsc.201300113 SN - 1618-2863 VL - 14 IS - 4 SP - 425 EP - 432 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Pasteur, Aline A1 - Tippkötter, Nils A1 - Kampeis, Percy A1 - Ulber, Roland T1 - Optimization of high gradient magnetic separation filter units for the purification of fermentation products JF - IEEE TRANSACTIONS ON MAGNETICS N2 - High gradient magnetic separation (HGMS) has been established since the early 1970s. A more recent application of these systems is the use in bioprocesses. To integrate the HGMS in a fermentation process, it is necessary to optimize the separation matrix with regard to the magnetic separation characteristics and permeability of the non-magnetizable components of the fermentation broth. As part of the work presented here, a combined fluidic and magnetic force finite element model simulation was created using the software COMSOL Multiphysics and compared with separation experiments. Finally, as optimal lattice orientation of the separation matrix, a transversal rhombohedral arrangement was defined. The high suitability of the new filter matrix has been verified by separation experiments. Y1 - 2014 U6 - https://doi.org/10.1109/TMAG.2014.2325535 SN - 0018-9464 N1 - Article Sequence Number: 5000607 INSPEC Accession Number: 14663042 VL - 50 IS - 10 SP - Artikel 5000607 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Thiel, Alexander A1 - Muffler, Kai A1 - Tippkötter, Nils A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Hruschka, Steffen M. A1 - Ulber, Roland T1 - A novel integrated downstream processing approach to recover sinapic acid, phytic acid and proteins from rapeseed meal JF - Journal of Chemical Technology and Biotechnology N2 - BACKGROUND Currently, several techniques exist for the downstream processing of protein, phytic acid and sinapic acid from rapeseed and rapeseed meal, but no technique has been developed to separate all of the components in one process. In this work, two new downstream processing strategies focusing on recovering sinapic acid, phytic acid and protein from rapeseed meal were established. RESULTS The sinapic acid content was enhanced by a factor of 4.5 with one method and 5.1 with the other. The isolation of sinapic acid was accomplished using a zeolite-based adsorbent with high adsorptive and optimal desorption characteristics. Phytic acid was isolated using the anion-exchange resin Purolite A200®. In addition, the processes resulted in two separated protein fractions. The ratios of globulin and albumin ratio to the total protein were 59.2% and 40.1%, respectively. The steps were then combined in two different ways: (a) a ‘sequential process’ using the zeolite and A200 in batch processes; and (b) a ‘parallel process’ using only A200 in a chromatographic system to separate all of the compounds. CONCLUSIONS It can be concluded that isolation of all three components was possible in both processes. These could enhance the added value of current processes using rapeseed meal as a protein source. © 2015 Society of Chemical Industry Y1 - 2015 U6 - https://doi.org/10.1002/jctb.4664 VL - 90 IS - 11 SP - 1999 EP - 2006 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Duwe, Anna A1 - Huster, Manuel A1 - Muffler, Kai A1 - Schlegel, Christin A1 - Tim, Sieker A1 - Stadtmüller, Ralf A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Biotechnology and bioprocess engineering – from the first ullmann's article to recent trends JF - ChemBioEng Reviews N2 - For several thousand years, biotechnology and its associated technical processes have had a great impact on the development of mankind. Based on empirical methods, in particular for the production of foodstuffs and daily commodities, these disciplines have become one of the most innovative future issues. Due to the increasing detailed understanding of cellular processes, production strains can now be optimized. In combination with modern bioprocesses, a variety of bulk and fine chemicals as well as pharmaceuticals can be produced efficiently. In this article, some of the current trends in biotechnology are discussed. Y1 - 2015 U6 - https://doi.org/10.1002/cben.201500008 VL - 2 IS - 3 SP - 175 EP - 184 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Tippkötter, Nils T1 - Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase JF - Engineering in Life Sciences N2 - In the field of biotechnology and molecular biology, the use of small liquid volumes has significant advantages. In particular, screening and optimization runs with acceptable amounts of expensive and hardly available catalysts, reagents, or biomolecules are feasible with microfluidic technologies. The presented new microfluidic system is based on the inclusion of small liquid volumes by a protective shell of magnetizable microparticles. Hereby, discrete aqueous microreactor drops with volumes of 1–30 μL can be formed on a simple planar surface. A digital movement and manipulation of the microreactor is performed by overlapping magnetic forces. The magnetic forces are generated by an electrical coil matrix positioned below a glass plate. With the new platform technology, several discrete reaction compartments can be moved simultaneously on one surface. Due to the magnetic fields, the reactors can even be merged to initiate reactions by mixing or positioned above surface-immobilized catalysts and then opened by magnetic force. Comparative synthesis routes of the magnetizable shell particles and superhydrophobic glass slides including their performance and stability with the reaction platform are described. The influence of diffusive mass transport during the catalyzed reaction is discussed by evaluation finite element model of the microreactor. Furthermore, a first model dye reaction of the enzyme laccase has been established. Y1 - 2016 U6 - https://doi.org/10.1002/elsc.201400124 VL - 16 IS - 3 SP - 222 EP - 230 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Roth, Jasmine A1 - Tippkötter, Nils T1 - Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium JF - Cellulose Chemistry and Technology N2 - Butanol is a promising gasoline additive and platform chemical that can be readily produced via acetone-butanolethanol (ABE) fermentation from pretreated lignocellulosic materials. This article examines lignocellulosic material from beech wood for ABE fermentation, using Clostridium acetobutylicum. First, the utilization of both C₅₋ (xylose) and C₆₋ (glucose) sugars as sole carbon source was investigated in static cultivation, using serum bottles and synthetic medium. The utilization of pentose sugar resulted in a solvent yield of 0.231 g·g_sugar⁻¹, compared to 0.262 g·g_sugar⁻¹ using hexose. Then, the Organosolv pretreated crude cellulose fibers (CF) were enzymatically decomposed, and the resulting hydrolysate medium was analyzed for inhibiting compounds (furans, organic acids, phenolics) and treated with ionexchangers for detoxification. Batch fermentation in a bioreactor using CF hydrolysate medium resulted in a total solvent yield of 0.20 gABE·g_sugar⁻¹. Y1 - 2016 VL - 50 IS - 3-4 SP - 405 EP - 410 PB - Editura Academiei Romane CY - Bukarest ER - TY - JOUR A1 - Rösch, C. A1 - Kratz, F. A1 - Hering, T. A1 - Trautmann, S. A1 - Umanskaya, N. A1 - Tippkötter, Nils A1 - Müller-Renno, C.M. A1 - Ulber, Roland A1 - Hannig, M. A1 - Ziegler, C. T1 - Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity JF - Colloids and Surfaces B: Biointerfaces N2 - The interplay of albumin (BSA) and lysozyme (LYZ) adsorbed simultaneously on titanium was analyzed by gel electrophoresis and BCA assay. It was found that BSA and lysozyme adsorb cooperatively. Additionally, the isoelectric point of the respective protein influences the adsorption. Also, the enzymatic activity of lysozyme and amylase (AMY) in mixtures with BSA was considered with respect to a possible influence of protein-protein interaction on enzyme activity. Indeed, an increase of lysozyme activity in the presence of BSA could be observed. In contrast, BSA does not influence the activity of amylase. Y1 - 2016 U6 - https://doi.org/10.1016/j.colsurfb.2016.09.048 VL - 149 IS - 1 SP - 115 EP - 121 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Schreiber, Marc A1 - Kraft, Bodo A1 - Zündorf, Albert ED - Bilof, Randall T1 - Metrics driven research collaboration: focusing on common project goals continuously T2 - Proceedings : 2017 IEEE/ACM 4th International Workshop on Software Engineering Research and Industrial Practice : SER&IP 2017 : 21 May 2017 Buenos Aires, Argentina Y1 - 2017 SN - 978-1-5386-2797-6 U6 - https://doi.org/10.1109/SER-IP.2017..6 SP - 41 EP - 47 PB - IEEE Press CY - Piscataway, NJ ER - TY - JOUR A1 - Horbach, Andreas A1 - Duong, Minh Tuan A1 - Staat, Manfred T1 - Modelling of compressible and orthotropic surgical mesh implants based on optical deformation measurement JF - Journal of the mechanical behavior of biomedical materials Y1 - 2017 U6 - https://doi.org/10.1016/j.jmbbm.2017.06.012 SN - 1751-6161 VL - 74 SP - 400 EP - 410 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - de Honde, Lukas A1 - Porst, Dariusz A1 - Digel, Ilya ED - Fischerauer, Alice T1 - A randomized, observational thermographic study of the neck region before and after a physiotherapeutic intervention T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 122 EP - 123 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Schlemmer, Katharina A1 - Porst, Dariusz A1 - Bassam, Rasha A1 - Artmann, Gerhard A1 - Digel, Ilya ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Effects of nitric oxide (NO) and ATP on red blood cell phenotype and deformability T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 100 EP - 101 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Schneider, Oliver A1 - Al Hakim, Taher A1 - Kayser, Peter A1 - Digel, Ilya ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Development and trials of a test chamber for ultrasound-assisted sampling of living cells from solid surfaces T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 96 EP - 97 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Kuhlen, Max A1 - Digel, Ilya ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Fluorescence signatures and detection limits of ubiquitous terrestrial bio-compounds T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 102 EP - 103 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Suryoputri, Nathania A1 - Ghaderi, Aydin A1 - Linder, Peter A1 - Kotliar, Konstantin A1 - Göttler, Jens A1 - Sorg, Christian A1 - Grimmer, Timo ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Does hemodynamic response function change in Alzheimer disease? T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 92 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Jabbari, Medisa A1 - Bhattarai, Aroj A1 - Anding, Ralf A1 - Staat, Manfred ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Biomechanical simulation of different prosthetic meshes for repairing uterine/vaginal vault prolapse T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 118 EP - 119 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Birgel, Stefan A1 - Leschinger, Tim A1 - Wegmann, Kilian A1 - Staat, Manfred ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Calculation of muscle forces and joint reaction loads in shoulder area via an OpenSim based computer calculation T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 N1 - In der Druckausgabe des Abstractbandes ist dieser Beitrag lose als Erratum beigefügt. SP - 116 EP - 117 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Abel, Alexander A1 - Pérez-Viana, Daniel A1 - Ciritsis, Bernard A1 - Staat, Manfred ED - Erni, Daniel ED - Fischerauer, Alice ED - Himmel, Jörg ED - Seeger, Thomas ED - Thelen, Klaus T1 - Prevention of femur neck fractures through femoroplasty T2 - 2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West Y1 - 2017 SN - 978-3-9814801-9-1 U6 - https://doi.org/10.17185/duepublico/43984 N1 - A young researchers track of the 7th IEEE Workshop & SENSORICA 2017 SP - 114 EP - 115 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - JOUR A1 - Michael, Hackl A1 - Mayer, Katharina A1 - Weber, Mareike A1 - Staat, Manfred A1 - van Riet, Roger A1 - Burkhart, Klau Josef A1 - Müller, Lars Peter A1 - Wegmann, Kilian T1 - Plate osteosynthesis of proximal ulna fractures : a biomechanical micromotion analysis JF - The journal of hand surgery Y1 - 2017 U6 - https://doi.org/10.1016/j.jhsa.2017.05.014 SN - 0363-5023 VL - 42 IS - 10 SP - 834.e1 EP - 834.e7 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Yoshinobu, Tatsuo A1 - Miyamoto, Ko-ichiro A1 - Werner, Frederik A1 - Poghossian, Arshak A1 - Wagner, Torsten A1 - Schöning, Michael Josef T1 - Light-addressable potentiometric sensors for quantitative spatial imaging of chemical species JF - Annual Review of Analytical Chemistry N2 - A light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor, in which a measurement site on the sensing surface is defined by illumination. This light addressability can be applied to visualize the spatial distribution of pH or the concentration of a specific chemical species, with potential applications in the fields of chemistry, materials science, biology, and medicine. In this review, the features of this chemical imaging sensor technology are compared with those of other technologies. Instrumentation, principles of operation, and various measurement modes of chemical imaging sensor systems are described. The review discusses and summarizes state-of-the-art technologies, especially with regard to the spatial resolution and measurement speed; for example, a high spatial resolution in a submicron range and a readout speed in the range of several tens of thousands of pixels per second have been achieved with the LAPS. The possibility of combining this technology with microfluidic devices and other potential future developments are discussed. Y1 - 2017 U6 - https://doi.org/10.1146/annurev-anchem-061516-045158 SN - 1936-1327 VL - 10 SP - 225 EP - 246 PB - Annual Reviews CY - Palo Alto, Calif. ER - TY - JOUR A1 - Sousa, Marcos A. M. A1 - Siqueira, Jose R. Jr. A1 - Vercik, Andres A1 - Schöning, Michael Josef A1 - Oliveira, Osvaldo N. Jr. T1 - Determining the optimized layer-by-layer film architecture with dendrimer/carbon nanotubes for field-effect sensors JF - IEEE Sensors Journal N2 - The capacitive electrolyte–insulator–semiconductor (EIS) structure is a typical device based on a field-effect sensor platform. With a simple silicon-based structure, EIS have been useful for several sensing applications, especially with incorporation of nanostructured films to modulate the ionic transport and the flat-band potential. In this paper, we report on ion transport and changes in flat-band potential in EIS sensors made with layer-by-layer films containing poly(amidoamine) (PAMAM) dendrimer and single-walled carbon nanotubes (SWNTs) adsorbed on p-Si/SiO 2 /Ta 2 O 5 chips with an Al ohmic contact. The impedance spectra were fitted using an equivalent circuit model, from which we could determine parameters such as the double-layer capacitance. This capacitance decreased with the number of bilayers owing to space charge accumulated at the electrolyte–insulator interface, up to three PAMAM/SWNTs bilayers, after which it stabilized. The charge-transfer resistance was also minimum for three bilayers, thus indicating that this is the ideal architecture for an optimized EIS performance. The understanding of the influence of nanostructures and the fine control of operation parameters pave the way for optimizing the design and performance of new EIS sensors. Y1 - 2017 U6 - https://doi.org/10.1109/JSEN.2017.2653238 SN - 1558-1748 VL - 17 IS - 6 SP - 1735 EP - 1740 PB - IEEE CY - New York ER - TY - JOUR A1 - Gamella, Maria A1 - Zakharchenko, Andrey A1 - Guz, Nataliia A1 - Masi, Madeline A1 - Minko, Sergiy A1 - Kolpashchikov, Dmitry M. A1 - Iken, Heiko A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Katz, Evgeny T1 - DNA computing system activated by electrochemically triggered DNA realease from a polymer-brush-modified electrode array JF - Electroanalysis N2 - An array of four independently wired indium tin oxide (ITO) electrodes was used for electrochemically stimulated DNA release and activation of DNA-based Identity, AND and XOR logic gates. Single-stranded DNA molecules were loaded on the mixed poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA)/poly(methacrylic acid) (PMAA) brush covalently attached to the ITO electrodes. The DNA deposition was performed at pH 5.0 when the polymer brush is positively charged due to protonation of tertiary amino groups in PDMAEMA, thus resulting in electrostatic attraction of the negatively charged DNA. By applying electrolysis at −1.0 V(vs. Ag/AgCl reference) electrochemical oxygen reduction resulted in the consumption of hydrogen ions and local pH increase near the electrode surface. The process resulted in recharging the polymer brush to the negative state due to dissociation of carboxylic groups of PMAA, thus repulsing the negatively charged DNA and releasing it from the electrode surface. The DNA release was performed in various combinations from different electrodes in the array assembly. The released DNA operated as input signals for activation of the Boolean logic gates. The developed system represents a step forward in DNA computing, combining for the first time DNA chemical processes with electronic input signals. Y1 - 2017 U6 - https://doi.org/10.1002/elan.201600389 SN - 1521-4109 VL - 29 IS - 2 SP - 398 EP - 408 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Schreiber, Marc A1 - Kraft, Bodo A1 - Zündorf, Albert T1 - Metrics Driven Research Collaboration: Focusing on Common Project Goals Continuously T2 - 39th International Conference on Software Engineering, May 20-28, 2017 - Buenos Aires, Argentina N2 - Research collaborations provide opportunities for both practitioners and researchers: practitioners need solutions for difficult business challenges and researchers are looking for hard problems to solve and publish. Nevertheless, research collaborations carry the risk that practitioners focus on quick solutions too much and that researchers tackle theoretical problems, resulting in products which do not fulfill the project requirements. In this paper we introduce an approach extending the ideas of agile and lean software development. It helps practitioners and researchers keep track of their common research collaboration goal: a scientifically enriched software product which fulfills the needs of the practitioner’s business model. This approach gives first-class status to application-oriented metrics that measure progress and success of a research collaboration continuously. Those metrics are derived from the collaboration requirements and help to focus on a commonly defined goal. An appropriate tool set evaluates and visualizes those metrics with minimal effort, and all participants will be pushed to focus on their tasks with appropriate effort. Thus project status, challenges and progress are transparent to all research collaboration members at any time. Y1 - 2017 N1 - Software Engineering in Practice (SEIP). ICSE2017 Vorabversion der Autoren ER - TY - CHAP A1 - Bitz, Andreas A1 - Streckert, J. A1 - Hansen, V.W. A1 - Buschmann, J. T1 - RF exposure of non restrained animals in an overmoded radial waveguide T2 - 22nd BEMS Annual Meeting, Munich, Germany, 2000 Y1 - 2000 SP - 63 PB - Bioelectromagnetics Society CY - Frederick, MD ER - TY - CHAP A1 - Bitz, Andreas A1 - Streckert, J.R. A1 - Hansen, V.W. A1 - Lerchl, A. ED - Danesy, Dorothea T1 - Freely moving or restrained animals in bioelec-tromagnetic experiments - pros and cons T2 - AP 2000 : Millennium Conference on Antennas & Propagation, Davos, Switzerland, 9 - 14 April 2000 Y1 - 2000 IS - Band 1 SP - 489 PB - ESA Publications Division, ESTEC CY - Noordwijk ER - TY - CHAP A1 - Bitz, Andreas A1 - Streckert, J. A1 - Hansen, V.W. A1 - Stogbauer, F. ED - Hietanen, Maila ED - Jokela, Kari ED - Juutilainen, Jukka ED - Työterveyslaitos, T1 - Shielded RF-exposure system with an integrated LF-measuring system for in vitro experiments with cell-layers T2 - Proceedings of the Ebea 2001 : 5th International Congress of the European Bioelectromagnetics Association (Ebea) ; 6-8 September 2001, Marina Congress Center, Helsinki, Finland Y1 - 2001 SN - 9789518024401 SP - 67 EP - 68 PB - Finnish Institute of Occupational Health CY - Helsinki ER - TY - CHAP A1 - Bitz, Andreas A1 - Alaydrus, M. A1 - Streckert, J. A1 - Hansen, V.W. T1 - Base station antennas embedded in complex environments: rf exposure in controlled areas T2 - 23rd BEMS Annual Meeting, St. Paul, Minnesota, USA, 49-50, June 2001 Y1 - 2001 SP - 49 EP - 50 PB - Bioelectromagnetics Society CY - Frederick, MD ER - TY - CHAP A1 - Bitz, Andreas A1 - Alaydrus, M. A1 - Streckert, J. A1 - Hansen, V.W. T1 - Absorption rates inside human body due to radiated electro-magnetic fields of multi-band base station antennas. Boundary value problems with electrically large and high-resolution bodies T2 - 24th BEMS Annual Meeting, Quebec City, Quebec, Canada, 23 - 27 June 2002 Y1 - 2002 SP - 40 EP - 41 PB - Bioelectromagnetics Society CY - Frederick, MD ER - TY - CHAP A1 - Bitz, Andreas A1 - Alaydrus, M. A1 - Streckert, J. A1 - Hansen, V. T1 - Combination of the hybrid/sup [2]/-method and the FDTD-method for solution of boundary value problems with electrically large and high-resolution bodies T2 - IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313) 2002 : San Antonio, TX, USA, 16-21 June Y1 - 2002 SN - 0-7803-7330-8 U6 - https://doi.org/10.1109/APS.2002.1018209 SP - 278 EP - 281 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Bitz, Andreas A1 - El Ouardi, A. A1 - Streckert, J. A1 - Hansen, V. T1 - Efficient calculation of human exposure in front of base station antennas by a combination of the FDTD and Hybrid(2)-method T2 - Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility, Topical Meeting on Biomedical EMC, Zurich, Switzerland, February 2005 Y1 - 2005 SN - 3-9521199-9-7 SP - 115 EP - 118 PB - ETH Zentrum CY - Zürich ER - TY - CHAP A1 - Bitz, Andreas A1 - Klomp, D.W. A1 - Ladd, M.E. T1 - Experimental and numerical determination of SAR and temperature distribution of a human endorectal coil for MR imaging of the prostate at 7T (903.) T2 - 16th annual ISMRM scientific meeting and exhibition 2008 : Toronto, Ontario, Canada, 3 - 9 May 2008 Y1 - 2009 SN - 978-1-61567-196-0 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Granat, Andreas A1 - Höfken, Hans-Wilhelm A1 - Schuba, Marko T1 - Intrusion Detection of the ICS Protocol EtherCAT N2 - Control mechanisms like Industrial Controls Systems (ICS) and its subgroup SCADA (Supervisory Control and Data Acquisition) are a prerequisite to automate industrial processes. While protection of ICS on process management level is relatively straightforward – well known office IT security mechanisms can be used – protection on field bus level is harder to achieve as there are real-time and production requirements like 24x7 to consider. One option to improve security on field bus level is to introduce controls that help to detect and to react on attacks. This paper introduces an initial set of intrusion detection mechanisms for the field bus protocol EtherCAT. To this end existing Ethernet attack vectors including packet injection and man-in-the-middle attacks are tested in an EtherCAT environment, where they could interrupt the EtherCAT network and may even cause physical damage. Based on the signatures of such attacks, a preprocessor and new rule options are defined for the open source intrusion detection system Snort demonstrating the general feasibility of intrusion detection on field bus level. Y1 - 2017 N1 - International Conference on Computer, Network Security and Communication Engineering (CNSCE 2017), March 26-27, 2017, Bangkok, Thailand SP - 1 EP - 5 ER - TY - CHAP A1 - Schwanke, Peter A1 - Höfken, Hans-Wilhelm A1 - Schuba, Marko T1 - Security Analysis of the ADS Protocol of a Beckhoff CX2020 PLC N2 - ICSs (Industrial Control Systems) and its subset SCADA systems (Supervisory Control and Data Acquisition) are getting exposed to a constant stream of new threats. The increasing importance of IT security in ICS requires viable methods to assess the security of ICS, its individual components, and its protocols. This paper presents a security analysis with focus on the communication protocols of a single PLC (Programmable Logic Controller). The PLC, a Beckhoff CX2020, is examined and new vulnerabilities of the system are revealed. Based on these findings recommendations are made to improve security of the Beckhoff system and its protocols. Y1 - 2017 N1 - International Conference on Computer, Network Security and Communication Engineering (CNSCE 2017), March 26-27, 2017, Bangkok, Thailand SP - 1 EP - 5 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 - https://doi.org/10.1515/teme-2017-0015 VL - 84 IS - 10 SP - 628 EP - 634 PB - De Gruyter CY - Oldenbourg ER - TY - JOUR A1 - Arreola, Julio A1 - Oberländer, Jan A1 - Mätzkow, M. A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Surface functionalization for spore-based biosensors with organosilanes JF - Electrochimica Acta N2 - In the present work, surface functionalization of different sensor materials was studied. Organosilanes are well known to serve as coupling agent for biomolecules or cells on inorganic materials. 3-aminopropyltriethoxysilane (APTES) was used to attach microbiological spores time to an interdigitated sensor surface. The functionality and physical properties of APTES were studied on isolated sensor materials, namely silicon dioxide (SiO2) and platinum (Pt) as well as the combined material on sensor level. A predominant immobilization of spores could be demonstrated on SiO2 surfaces. Additionally, the impedance signal of APTES-functionalized biosensor chips has been investigated. Y1 - 2017 U6 - https://doi.org/10.1016/j.electacta.2017.04.157 SN - 0013-4686 VL - 241 SP - 237 EP - 243 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Bitz, Andreas A1 - Kraff, O. A1 - Orzada, S. A1 - Maderwald, S. A1 - Brote, I. A1 - Ladd, M. T1 - Experimental and Numerical Assessment of RF Safety of Transmit Coils at 7 Tesla T2 - ISMRM workshop on MR safety 2010 : RF heating of the human in MRI : workshop series. The Washington County Historic Courthouse, Stillwater, Minnesota, USA, 15 - 17 October 2010 Y1 - 2010 SN - 978-1-62276-088-6 SP - 195 ER - TY - CHAP A1 - Bitz, Andreas A1 - Kraff, O. A1 - Orzada, S. A1 - Maderwald, S. A1 - Brote, I. A1 - Johst, S. A1 - Ladd, E. T1 - Assessment of RF Safety of Transmit Coils at 7 Tesla by Experimental and Numerical Procedures (490.) T2 - 19th annual ISMRM scientific meeting and exhibition 2011 : Montreal, Quebec, Canada, 7 - 13 May 2011 Y1 - 2012 SN - 978-1-61839-284-8 IS - Volume 1 SP - 475 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Bitz, Andreas A1 - Kobus, Thiele A1 - Scheenen, Tom W. J. A1 - Ladd, Mark E. T1 - RF Safety of the Combination of a 31P Tx/Rx Endorectal Coil & a 1H Tx/Rx Body Array for 31P MRSI of the Prostate at 7T (311.) T2 - 20th Annual ISMRM scientific meeting and exhibition 2012 : Melbourne, Australia, 5 - 11 May 2012 Y1 - 2013 SN - 978-1-62276-943-8 SN - 1545-4428 IS - Volume 1 SP - 311 PB - Curran CY - Red Hook, NY ER - TY - JOUR A1 - Hansen, Volkert W. A1 - Bitz, Andreas A1 - Streckert, Joachim R. T1 - RF Exposure of Biological Systems in Radial Waveguides JF - IEEE Transactions on Electromagnetic Compatibility Y1 - 1999 U6 - https://doi.org/10.1109/15.809852 SN - 1558-187X VL - 41 IS - 4 SP - 487 EP - 493 ER - TY - JOUR A1 - Sommer, Angela M. A1 - Streckert, Joachim A1 - Bitz, Andreas A1 - Hansen, Volkert W. A1 - Lerchl, Alexander T1 - No effects of GSM-modulated 900 MHz electromagnetic fields on survival rate and spontaneous development of lymphoma in female AKR/J mice JF - BMC Cancer Y1 - 2004 U6 - https://doi.org/10.1186/1471-2407-4-77 VL - 77 IS - 4 ER - TY - JOUR A1 - Ndoumbè Mbonjo Mbonjo, H. A1 - Streckert, J. A1 - Bitz, Andreas A1 - Hansen, V. A1 - Glasmachers, A. A1 - Gencol, S. A1 - Rozic, D. T1 - Generic UMTS test signal for RF bioelectromagnetic studies JF - Bioelectromagnetics Y1 - 2004 U6 - https://doi.org/10.1002/bem.20007 SN - 1521-186X VL - 25 IS - 6 SP - 415 EP - 425 ER - TY - CHAP A1 - Thurn, Laura A1 - Gebhardt, Andreas T1 - Arousing Enthusiasm for STEM: Teaching 3D Printing Technology T2 - Conference Proceedings: New Perspectives in Science Education Y1 - 2017 SN - 978-88-6292-847-2 SP - 87 EP - 92 PB - liberiauniversitaria.it CY - Padua ER - TY - CHAP A1 - Neu, Eugen A1 - Janser, Frank A1 - Khatibi, Akbar A. A1 - Orifici, Adrian C. T1 - In-flight vibration-based structural health monitoring of aircraft wings T2 - 30th Congress of the internatonal council of the aeronautical sciences : 25.-30. September 2016, Daejeon, Korea N2 - This work presents a methodology for automated damage-sensitive feature extraction and anomaly detection under multivariate operational variability for in-flight assessment of wings. The method uses a passive excitation approach, i. e. without the need for artificial actuation. The modal system properties (natural frequencies and damping ratios) are used as damage-sensitive features. Special emphasis is placed on the use of Fiber Bragg Grating (FBG) sensing technology and the consideration of Operational and Environmental Variability (OEV). Measurements from a wind tunnel investigation with a composite cantilever equipped with FBG and piezoelectric sensors are used to successfully detect an impact damage. In addition, the feasibility of damage localisation and severity estimation is evaluated based on the coupling found between damageand OEV-induced feature changes. Y1 - 2016 ER -