@article{KraffWredeSchoembergetal.2013, author = {Kraff, Oliver and Wrede, Karsten H. and Schoemberg, Tobias and Dammann, Philipp and Noureddine, Yacine and Orzada, Stephan and Ladd, Mark E. and Bitz, Andreas}, title = {MR safety assessment of potential RF heating from cranial fixation plates at 7 T}, series = {Medical Physics}, volume = {40}, journal = {Medical Physics}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {2473-4209}, doi = {10.1118/1.4795347}, pages = {042302-1 -- 042302-10}, year = {2013}, language = {en} } @article{UmutluMaderwaldKinneretal.2013, author = {Umutlu, L. and Maderwald, S. and Kinner, S. and Kraff, O. and Bitz, Andreas and Orzada, S. and Johst, S. and Wrede, K. and Forsting, M. and Ladd, M. E. and Lauenstein, T. C. and Quick, H. H.}, title = {First-pass contrast-enhanced renal MRA at 7 Tesla: initial results}, series = {European Radiology}, volume = {23}, journal = {European Radiology}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1432-1084}, doi = {10.1007/s00330-012-2666-0}, pages = {1059 -- 1066}, year = {2013}, language = {en} } @article{OrzadaJohstMaderwaldetal.2013, author = {Orzada, Stephan and Johst, S{\"o}ren and Maderwald, Stefan and Bitz, Andreas and Solbach, Klaus and Ladd, Mark E.}, title = {Mitigation of B1(+) inhomogeneity on single-channel transmit systems with TIAMO}, series = {Magnetic Resonance in Medicine}, volume = {70}, journal = {Magnetic Resonance in Medicine}, number = {1}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2594}, doi = {10.1002/mrm.24453}, pages = {290 -- 294}, year = {2013}, language = {en} } @article{UmutluBitzMaderwaldetal.2013, author = {Umutlu, Lale and Bitz, Andreas and Maderwald, Stefan and Orzada, Stephan and Kinner, Sonja and Kraff, Oliver and Brote, Irina and Ladd, Susanne C. and Schroeder, Tobias and Forsting, Michael}, title = {Contrast-enhanced ultra-high-field liver MRI: a feasibility trial}, series = {European Journal of Radiology}, volume = {82}, journal = {European Journal of Radiology}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0720-048X}, doi = {10.1016/j.ejrad.2011.07.004}, pages = {760 -- 767}, year = {2013}, language = {en} } @article{ThielTippkoetterSucketal.2013, author = {Thiel, Alexander and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland}, title = {New zeolite adsorbents for downstream processing of polyphenols from renewable resources}, series = {Engineering in Life Sciences}, volume = {13}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/elsc.201200188}, pages = {239 -- 246}, year = {2013}, abstract = {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.}, language = {en} } @article{TippkoetterAlKaidyWollnyetal.2013, author = {Tippk{\"o}tter, Nils and Al-Kaidy, Huschyar and Wollny, Steffen and Ulber, Roland}, title = {Functionalized magnetizable particles for downstream processing in single-use systems}, series = {Chemie Ingenieur Technik}, volume = {85}, journal = {Chemie Ingenieur Technik}, number = {1-2: Special Issue: Single-Use Technology}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/cite.201200130}, pages = {76 -- 86}, year = {2013}, abstract = {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.}, language = {en} } @article{PellegriniHowellShepherdetal.2013, author = {Pellegrini, Paul A. and Howell, Nicholas R. and Shepherd, Rachael K. and Lengkeek, Nigel A. and Paulßen, Elisabeth and Katsifis, Andrew G. and Greguric, Ivan}, title = {Synthesis and Radiolabelling of DOTA-Linked Glutamine Analogues with 67,68Ga as Markers for Increased Glutamine Metabolism in Tumour Cells}, series = {Molecules}, volume = {18}, journal = {Molecules}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1420-3049}, doi = {10.3390/molecules18067160}, pages = {7160 -- 7178}, year = {2013}, language = {en} } @article{PaulssenLeLengkeeketal.2013, author = {Paulßen, Elisabeth and Le, Van So and Lengkeek, Nigel and Pellegrini, Paul and Jackson, Tim and Greguric, Ivan and Weiner, Ron}, title = {Influence of Metal Ions on the 68Ga-labeling of DOTATATE}, series = {Applied Radiation and Isotopes}, volume = {82}, journal = {Applied Radiation and Isotopes}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-9800}, doi = {10.1016/j.apradiso.2013.08.010}, pages = {232 -- 238}, year = {2013}, language = {en} } @article{WeiheErnstRoethetal.2013, author = {Weihe, Stefan and Ernst, Ansgar and R{\"o}th, Thilo and Proksch, Johannes}, title = {Aluminium-Stahl-Verbundguss im Nutzfahrzeugbau}, series = {ATZ - Automobiltechnische Zeitschrift}, volume = {115}, journal = {ATZ - Automobiltechnische Zeitschrift}, number = {4}, publisher = {Springer Fachmedien Wiesbaden}, issn = {2192-8800 (Online)}, pages = {312 -- 316}, year = {2013}, abstract = {In modernen Fahrzeugkarosserien der Großserie kommen zunehmend Materialmischbauweisen zur Anwendung. In Zusammenarbeit der Daimler AG, der Tower Automotive Holding GmbH, der Imperia GmbH sowie der Partnerunternehmen KSM Castings GmbH und Schaufler Tooling GmbH \& Co. KG wird das Leichtbaupotenzial von Aluminiumverbundguss-Stahlblech-Hybriden am Beispiel des vorderen Dachquertr{\"a}gers des Mercedes-Benz Viano/Vito ausf{\"u}hrlich untersucht.}, language = {de} } @article{WeiheAnsgarRoethetal.2013, author = {Weihe, Stefan and Ansgar, Ernst and R{\"o}th, Thilo and Proksch, Johannes}, title = {Leichtmetall-Stahl-Verbundguss im Nutzfahrzeugbau}, series = {Lightweight Design}, volume = {6}, journal = {Lightweight Design}, number = {2}, publisher = {Springer}, address = {Berlin}, issn = {2192-8738 (Online)}, pages = {38 -- 43}, year = {2013}, abstract = {In modernen Fahrzeugkarosserien der Großserie kommen zunehmend Materialmischbauweisen zur Anwendung. In Zusammenarbeit der Daimler AG, der Tower Automotive Holding GmbH, der Imperia GmbH sowie der Partnerunternehmen KSM Castings GmbH und Schaufler Tooling GmbH \& Co. KG wird das Leichtbaupotenzial von Stahlblech-AluminiumverbundgussHybriden am Beispiel des vorderen Dachquertr{\"a}gers des Mercedes-Benz Viano/Vito ausf{\"u}hrlich untersucht.}, language = {de} } @article{BialonskiLehnertz2013, author = {Bialonski, Stephan and Lehnertz, Klaus}, title = {Assortative mixing in functional brain networks during epileptic seizures}, series = {Chaos: An Interdisciplinary Journal of Nonlinear Science}, volume = {23}, journal = {Chaos: An Interdisciplinary Journal of Nonlinear Science}, number = {3}, doi = {10.1063/1.4821915}, pages = {033139}, year = {2013}, language = {en} } @article{BeverungenEggertVoigtetal.2013, author = {Beverungen, Daniel and Eggert, Mathias and Voigt, Matthias and Rosemann, Michael}, title = {Augmenting Analytical CRM Strategies with Social BI}, series = {International Journal of Business Intelligence Research (IJBIR)}, volume = {4}, journal = {International Journal of Business Intelligence Research (IJBIR)}, number = {3}, publisher = {IGI Global}, address = {Hershey}, issn = {1947-3591}, doi = {10.4018/ijbir.2013070103}, pages = {32 -- 49}, year = {2013}, language = {en} } @article{EggertKnackstedtFleischeretal.2013, author = {Eggert, Mathias and Knackstedt, Ralf and Fleischer, Stefan and Becker, J{\"o}rg}, title = {The Potential of Configurative Reference Modeling for Business to Government Reporting - A Modeling Technique and its Evaluation}, series = {e-Service Journal}, volume = {9}, journal = {e-Service Journal}, number = {1}, publisher = {Indiana University Press}, address = {Bloomington}, issn = {1528-8234}, pages = {28 -- 59}, year = {2013}, language = {en} } @article{OlbertzSturm2013, author = {Olbertz, Klaus and Sturm, Nora}, title = {Arbeitsrecht in der Insolvenz - Was gilt, wenn nichts mehr geht?}, series = {NWB - Steuer- und Wirtschaftsrecht}, journal = {NWB - Steuer- und Wirtschaftsrecht}, number = {45}, publisher = {NWB Verlag}, address = {Herne}, issn = {1860-9449}, pages = {3552 -- 3559}, year = {2013}, language = {de} } @article{Olbertz2013, author = {Olbertz, Klaus}, title = {GmbH-Gesch{\"a}ftsf{\"u}hrer - Kein arbeitsrechtsfreier Raum}, series = {Arbeit und Arbeitsrecht : AuA}, journal = {Arbeit und Arbeitsrecht : AuA}, publisher = {Huss-Medien GmbH}, address = {Berlin}, issn = {0323-4568}, pages = {400 -- 403}, year = {2013}, language = {de} } @article{KrollLudwigs2013, author = {Kroll-Ludwigs, Kathrin}, title = {Anmerkung zu EuGH, Urt. v. 26. April 2012, Rs. C-92/12 PPU - Health Service Executive}, series = {GRP : Zeitschrift f{\"u}r das Privatrecht der Europ{\"a}ischen Union}, journal = {GRP : Zeitschrift f{\"u}r das Privatrecht der Europ{\"a}ischen Union}, number = {1}, publisher = {Verlag Dr. Otto Schmidt}, address = {K{\"o}ln}, issn = {2193-9519}, pages = {46 -- 49}, year = {2013}, language = {de} } @article{BuckLaeubliMeyeretal.2013, author = {Buck, Raphael and L{\"a}ubli, Daniel and Meyer, Laura and Moosdorf, Andreas}, title = {Re-FRESH! Mit dem Frischesortiment punkten}, series = {Akzente}, journal = {Akzente}, number = {3}, pages = {36 -- 43}, year = {2013}, language = {de} } @article{GoergensGreubelMoosdorf2013, author = {G{\"o}rgens, Stefan and Greubel, Steffen and Moosdorf, Andreas}, title = {How to mobilize 20,000 people: Perspectives on retail and consumer goods}, pages = {52 -- 58}, year = {2013}, language = {en} } @article{AkimbekovDigelTastambeketal.2013, author = {Akimbekov, N. S. and Digel, Ilya and Tastambek, K. T. and Zhubanova, A. A.}, title = {Biocompatibility of carbonized rice husk with a rat heart cells line H9c2}, series = {Experimental Biology}, volume = {59}, journal = {Experimental Biology}, number = {3/1}, issn = {1563-0218}, pages = {23 -- 25}, year = {2013}, language = {en} } @article{AkimbekovDigelSavitkayaetal.2013, author = {Akimbekov, N.Sh. and Digel, Ilya and Savitkaya, I.S. and Zhubanova, A.A. and Tastambek, K.T.}, title = {Investigations of LPS endotoxin elimination in the flowing column conditions with the sorbent on the basis of carbonized rice husk}, series = {KazNU Bulletin. Biology series}, volume = {57}, journal = {KazNU Bulletin. Biology series}, number = {1}, issn = {1563-0218}, pages = {124 -- 127}, year = {2013}, language = {en} } @article{DigelAkimbekovTuralievaetal.2013, author = {Digel, Ilya and Akimbekov, N. and Turalieva, M. and Mansurov, Z. and Temiz Artmann, Ayseg{\"u}l and Eshibaev, A. and Zhubanova, A.}, title = {Usage of Carbonized Plant Wastes for Purification of Aqueous Solutions}, series = {Journal of Industrial Technology and Engineering}, volume = {2}, journal = {Journal of Industrial Technology and Engineering}, number = {07}, pages = {47 -- 54}, year = {2013}, language = {en} } @article{ZhubanovaMansurovDigeletal.2013, author = {Zhubanova, А. and Mansurov, Z.A. and Digel, Ilya and Saviskaya, I.S. and Akimbekov, N.Sh.}, title = {Designing of Heterogeneous Nanobiocomposites for Biotechnology}, series = {KazNU Bulletin. Biology series}, volume = {59}, journal = {KazNU Bulletin. Biology series}, number = {No 3/1}, isbn = {1563-0218}, pages = {89 -- 93}, year = {2013}, language = {ru} } @article{AkimbekovDigelZhubanova2013, author = {Akimbekov, N. Sh. and Digel, Ilya and Zhubanova, A. A.}, title = {Investigation the Influence of Carbonized Material Based On Rice Husk on Viability and Migration of Fibroblasts in T3B3 Cell Culture}, series = {KazNU Bulletin. Biology series}, volume = {59}, journal = {KazNU Bulletin. Biology series}, number = {3/1}, issn = {1563-0218}, pages = {20 -- 23}, year = {2013}, language = {en} } @article{ScheerWolf2013, author = {Scheer, Nico and Wolf, C. Roland}, title = {Xenobiotic receptor humanized mice and their utility}, series = {Drug Metabolism Reviews}, journal = {Drug Metabolism Reviews}, number = {1}, publisher = {Taylor \& Francis}, address = {London}, issn = {1097-9883}, doi = {10.3109/03602532.2012.738687}, pages = {110 -- 121}, year = {2013}, language = {en} } @article{ReisertSchneiderGeissleretal.2013, author = {Reisert, Steffen and Schneider, Benno and Geissler, Hanno and Gompel, Matthias van and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Multi-sensor chip for the investigation of different types of metal oxides for the detection of H2O2 in the ppm range}, series = {physica status solidi (a)}, volume = {210}, journal = {physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, pages = {898 -- 904}, year = {2013}, abstract = {In this work, a multi-sensor chip for the investigation of the sensing properties of different types of metal oxides towards hydrogen peroxide in the ppm range is presented. The fabrication process and physical characterization of the multi-sensor chip are described. Pure SnO2 and WO3 as well as Pd- and Pt-doped SnO2 films are characterized in terms of their sensitivity to H2O2. The sensing films have been prepared by drop-coating of water-dispensed nano-powders. A physical characterization, including scanning electron microscopy and X-ray diffraction analysis of the deposited metal-oxide films, was done. From the measurements in hydrogen peroxide atmosphere, it could be shown, that all of the tested metal oxide films are suitable for the detection of H2O2 in the ppm range. The highest sensitivity and reproducibility was achieved using Pt-doped SnO2. Calibration plot of a SnO2, WO3, Pt-, and Pd-doped SnO2 gas sensor for H2O2 concentrations in the ppm range.}, language = {en} } @article{WernerTakenagaTakietal.2013, author = {Werner, Frederik and Takenaga, Shoko and Taki, Hidenori and Sawada, Kazuaki and Sch{\"o}ning, Michael Josef}, title = {Comparison of label-free ACh-imaging sensors based on CCD and LAPS}, series = {Sensors and Actuators B: Chemical (2012)}, volume = {177}, journal = {Sensors and Actuators B: Chemical (2012)}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0925-4005}, pages = {745 -- 752}, year = {2013}, abstract = {Semiconductor-based chemical imaging sensors, like the light-addressable potentiometric sensor (LAPS) or the pH-imaging sensor based on a charge-coupled device (CCD), are becoming a powerful tool for label-free imaging of biological phenomena. We have proposed a polyion-based enzymatic membrane to develop an acetylcholine (ACh) imaging sensor for neural cell-activity observations. In this study, a CCD-type ACh-imaging sensor and a LAPS-type ACh-imaging sensor were fabricated and the prospect of both sensors was clarified by making a comparison of their basic characteristics.}, language = {en} } @article{CzarneckiWinkelmannSpiliopoulou2013, author = {Czarnecki, Christian and Winkelmann, Axel and Spiliopoulou, Myra}, title = {Referenzprozessabl{\"a}ufe f{\"u}r Telekommunikationsunternehmen: Eine Erweiterung des eTOM-Modells}, series = {Wirtschaftsinformatik}, volume = {55}, journal = {Wirtschaftsinformatik}, number = {2}, publisher = {Springer Fachmedien}, address = {Wiesbaden}, issn = {1861-8936}, doi = {10.1007/s11576-013-0351-9}, pages = {83 -- 97}, year = {2013}, abstract = {Der Telekommunikationsmarkt erf{\"a}hrt substanzielle Ver{\"a}nderungen. Neue Gesch{\"a}ftsmodelle, innovative Dienstleistungen und Technologien erfordern Reengineering, Transformation und Prozessstandardisierung. Mit der Enhanced Telecom Operation Map (eTOM) bietet das TM Forum ein international anerkanntes de facto Referenz-Prozess-Framework basierend auf spezifischen Anforderungen und Auspr{\"a}gungen der Telekommunikationsindustrie an. Allerdings enth{\"a}lt dieses Referenz-Framework nur eine hierarchische Sammlung von Prozessen auf unterschiedlichen Abstraktionsebenen. Eine Kontrollsicht verstanden als sequenzielle Anordnung von Aktivit{\"a}ten und daraus resultierend ein realer Prozessablauf fehlt ebenso wie eine Ende-zu-Ende-Sicht auf den Kunden. In diesem Artikel erweitern wir das eTOM-Referenzmodell durch Referenzprozessabl{\"a}ufe, in welchen wir das Wissen {\"u}ber Prozesse in Telekommunikationsunternehmen abstrahieren und generalisieren. Durch die Referenzprozessabl{\"a}ufe werden Unternehmen bei dem strukturierten und transparenten (Re-)Design ihrer Prozesse unterst{\"u}tzt. Wir demonstrieren die Anwendbarkeit und N{\"u}tzlichkeit unserer Referenzprozessabl{\"a}ufe in zwei Fallstudien und evaluieren diese anhand von Kriterien f{\"u}r die Bewertung von Referenzmodellen. Die Referenzprozessabl{\"a}ufe wurden vom TM Forum in den Standard aufgenommen und als Teil von eTOM Version 9 ver{\"o}ffentlicht. Dar{\"u}ber hinaus diskutieren wir die Komponenten unseres Ansatzes, die auch außerhalb der Telekommunikationsindustrie angewandt werden k{\"o}nnen.}, language = {de} } @article{PoghossianWeilCherstvyetal.2013, author = {Poghossian, Arshak and Weil, M. and Cherstvy, A. G. and Sch{\"o}ning, Michael Josef}, title = {Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices}, series = {Analytical and bioanalytical chemistry}, volume = {405}, journal = {Analytical and bioanalytical chemistry}, number = {20}, publisher = {Springer}, address = {Berlin}, issn = {1432-1130 ; 1618-2642}, doi = {10.1007/s00216-013-6951-9}, pages = {6425 -- 6436}, year = {2013}, abstract = {The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance-voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed.}, language = {en} } @article{HuckSchiffelsHerreraetal.2013, author = {Huck, Christina and Schiffels, Johannes and Herrera, Cony N. and Schelden, Maximilian and Selmer, Thorsten and Poghossian, Arshak and Baumann, Marcus and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201200900}, pages = {926 -- 931}, year = {2013}, abstract = {Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the "welfare" of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis-Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed.}, language = {en} } @article{BaeckerRakowskiPoghossianetal.2013, author = {B{\"a}cker, Matthias and Rakowski, D. and Poghossian, Arshak and Biselli, Manfred and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis}, series = {Journal of Biotechnology}, volume = {163}, journal = {Journal of Biotechnology}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-1656}, doi = {10.1016/j.jbiotec.2012.03.014}, pages = {371 -- 376}, year = {2013}, abstract = {A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses.}, language = {en} } @article{KirchnerOberlaenderSucoetal.2013, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suco, Henri-Pierre and Rysstad, Gunnar and Sch{\"o}ning, Michael Josef}, title = {Monitoring the microbicidal effectiveness of gaseous hydrogen peroxide in sterilisation processes by means of a calorimetric gas sensor}, series = {Food control}, volume = {31}, journal = {Food control}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0956-7135}, doi = {10.1016/j.foodcont.2012.11.048}, pages = {530 -- 538}, year = {2013}, abstract = {In the present work, a novel method for monitoring sterilisation processes with gaseous H2O2 in combination with heat activation by means of a specially designed calorimetric gas sensor was evaluated. Therefore, the sterilisation process was extensively studied by using test specimens inoculated with Bacillus atrophaeus spores in order to identify the most influencing process factors on its microbicidal effectiveness. Besides the contact time of the test specimens with gaseous H2O2 varied between 0.2 and 0.5 s, the present H2O2 concentration in a range from 0 to 8\% v/v (volume percent) had a strong influence on the microbicidal effectiveness, whereas the change of the vaporiser temperature, gas flow and humidity were almost negligible. Furthermore, a calorimetric H2O2 gas sensor was characterised in the sterilisation process with gaseous H2O2 in a wide range of parameter settings, wherein the measurement signal has shown a linear response against the H2O2 concentration with a sensitivity of 4.75 °C/(\% v/v). In a final step, a correlation model by matching the measurement signal of the gas sensor with the microbial inactivation kinetics was established that demonstrates its suitability as an efficient method for validating the microbicidal effectiveness of sterilisation processes with gaseous H2O2.}, language = {en} } @article{KirchnerOberlaenderSusoetal.2013, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suso, Henri-Pierre and Rysstad, Gunnar and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes}, series = {Physica status solidi (a)}, volume = {210}, journal = {Physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201200920}, pages = {877 -- 883}, year = {2013}, abstract = {A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests.}, language = {en} } @article{HennemannKohlReisertetal.2013, author = {Hennemann, J{\"o}rg and Kohl, Claus-Dieter and Reisert, Steffen and Kirchner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Copper oxide nanofibres for detection of hydrogen peroxide vapour at high concentrations}, series = {physica status solidi (a)}, volume = {210}, journal = {physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201200775}, pages = {859 -- 863}, year = {2013}, abstract = {We present a sensor concept based on copper(II)oxide (CuO) nanofibres for the detection of hydrogen peroxide (H2O2) vapour in the percent per volume (\% v/v) range. The fibres were produced by using the electrospinning technique. To avoid water condensation in the pores, the fibres were initially modified by an exposure to H2S to get an enclosed surface. By a thermal treatment at 350 °C the fibres were oxidised back to CuO. Thereby, the visible pores disappear which was verified by SEM analysis. The fibres show a decrease of resistance with increasing H2O2 concentration which is due to the fact that hydrogen peroxide is an oxidising gas and CuO a p-type semiconductor. The sensor shows a change of resistance within the minute range to the exposure until the maximum concentration of 6.9\% v/v H2O2. At operating temperatures below 450 °C the corresponding sensor response to a concentration of 4.1\% v/v increases. The sensor shows a good reproducibility of the signal at different measurements. CuO seems to be a suitable candidate for the detection of H2O2 vapour at high concentrations. Resistance behaviour of the sensor under exposure to H2O2 vapours between 2.3 and 6.9\% v/v at an operating temperature of 450 °C.}, language = {en} } @article{SchusserLeinhosBaeckeretal.2013, author = {Schusser, Sebastian and Leinhos, Marcel and B{\"a}cker, Matthias and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Impedance spectroscopy: A tool for real-time in situ monitoring of the degradation of biopolymers}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200941}, pages = {905 -- 910}, year = {2013}, abstract = {Investigation of the degradation kinetics of biodegradable polymers is essential for the development of implantable biomedical devices with predicted biodegradability. In this work, an impedimetric sensor has been applied for real-time and in situ monitoring of degradation processes of biopolymers. The sensor consists of two platinum thin-film electrodes covered by a polymer film to be studied. The benchmark biomedical polymer poly(D,L-lactic acid) (PDLLA) was used as a model system. PDLLA films were deposited on the sensor structure from a polymer solution by using the spin-coating method. The degradation kinetics of PDLLA films have been studied in alkaline solutions of pH 9 and 12 by means of an impedance spectroscopy (IS) method. Any changes in a polymer capacitance/resistance induced by water uptake and/or polymer degradation will modulate the global impedance of the polymer-covered sensor that can be used as an indicator of the polymer degradation. The degradation rate can be evaluated from the time-dependent impedance spectra. As expected, a faster degradation has been observed for PDLLA films exposed to pH 12 solution.}, language = {en} } @article{ItabashiKosakaMiyamotoetal.2013, author = {Itabashi, Akinori and Kosaka, Naoki and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {High-speed chemical imaging system based on front-side-illuminated LAPS}, series = {Sensors and actuators B: Chemical}, volume = {182}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077}, doi = {10.1016/j.snb.2013.03.016}, pages = {315 -- 321}, year = {2013}, abstract = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the spatial distribution of specific ions on the sensing surface. The conventional chemical imaging system based on the light-addressable potentiometric sensor (LAPS), however, required a long time to obtain a chemical image, due to the slow mechanical scan of a single light beam. For high-speed imaging, a plurality of light beams modulated at different frequencies can be employed to measure the ion concentrations simultaneously at different locations on the sensor plate by frequency division multiplex (FDM). However, the conventional measurement geometry of back-side illumination limited the bandwidth of the modulation frequency required for FDM measurement, because of the low-pass filtering characteristics of carrier diffusion in the Si substrate. In this study, a high-speed chemical imaging system based on front-side-illuminated LAPS was developed, which achieved high-speed spatiotemporal recording of pH change at a rate of 70 frames per second.}, language = {en} } @article{WernerWagnerYoshinobuetal.2013, author = {Werner, Frederik and Wagner, Torsten and Yoshinobu, Tatsuo and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Frequency behaviour of light-addressable potentiometric sensors}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200929}, pages = {884 -- 891}, year = {2013}, abstract = {Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed.}, language = {en} } @article{MiyamotoIchimuraWagneretal.2013, author = {Miyamoto, Ko-ichiro and Ichimura, Hiroki and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Chemical imaging of the concentration profile of ion diffusion in a microfluidic channel}, series = {Sensors and actuators. B: Chemical}, volume = {189}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2013.04.057}, pages = {240 -- 245}, year = {2013}, abstract = {The chemical imaging sensor is a device to visualize the spatial distribution of chemical species based on the principle of LAPS (light-addressable potentiometric sensor), which is a field-effect chemical sensor based on semiconductor. In this study, the chemical imaging sensor has been applied to investigate the ion profile of laminar flows in a microfluidic channel. The chemical images (pH maps) were collected in a Y-shaped microfluidic channel while injecting HCl and NaCl solutions into two branches. From the chemical images, it was clearly observed that the injected solutions formed laminar flows in the channel. In addition, ion diffusion across the laminar flows was observed, and the diffusion coefficient could be derived by fitting the pH profiles to the Fick's equation.}, language = {en} } @article{KuhnertBialonskiNoenningetal.2013, author = {Kuhnert, Marie-Therese and Bialonski, Stephan and Noenning, Nina and Mai, Heinke and Hinrichs, Hermann and Helmstaedter, Christoph and Lehnertz, Klaus}, title = {Incidental and intentional learning of verbal episodic material differentially modifies functional brain networks}, series = {Plos one}, volume = {8}, journal = {Plos one}, number = {11}, publisher = {PLOS}, address = {San Francisco}, doi = {10.1371/journal.pone.0080273}, pages = {e80273}, year = {2013}, abstract = {Learning- and memory-related processes are thought to result from dynamic interactions in large-scale brain networks that include lateral and mesial structures of the temporal lobes. We investigate the impact of incidental and intentional learning of verbal episodic material on functional brain networks that we derive from scalp-EEG recorded continuously from 33 subjects during a neuropsychological test schedule. Analyzing the networks' global statistical properties we observe that intentional but not incidental learning leads to a significantly increased clustering coefficient, and the average shortest path length remains unaffected. Moreover, network modifications correlate with subsequent recall performance: the more pronounced the modifications of the clustering coefficient, the higher the recall performance. Our findings provide novel insights into the relationship between topological aspects of functional brain networks and higher cognitive functions.}, language = {en} }