@article{CzarneckiGeierPflug2017, author = {Czarnecki, Christian and Geier, Jari and Pflug, Karolin}, title = {Netzvirtualisierung durch SDN und NFV : Unternehmensprozesse auf dem Pr{\"u}fstand}, series = {LANline}, journal = {LANline}, publisher = {AWI Aktuelles Wissen Verl.-Ges.}, address = {Trostberg}, issn = {0942-4172}, year = {2017}, abstract = {Kundenanforderungen an Netzwerke haben sich in den vergangenen Jahren stark ver{\"a}ndert. Mit NFV und SDN sind Unternehmen technisch in der Lage, diesen gerecht zu werden. Die Provider stehen jedoch vor großen Herausforderungen: Insbesondere Produkte und Prozesse m{\"u}ssen angepasst und agiler werden, um die St{\"a}rken von NFV und SDN zum Kundenvorteil auszuspielen.}, language = {de} } @article{CzarneckiHeuserKraemeretal.2006, author = {Czarnecki, Christian and Heuser, Marcus and Kr{\"a}mer, Christian and Stummer, Christoph and Theisinger, Felix and Wettklo, Michael}, title = {How to get more customer satisfaction : Erfolg im Wettbewerb durch kundenzentrierte Prozesse}, series = {Detecon Management Report}, journal = {Detecon Management Report}, number = {3}, publisher = {Detecon Internat. GmbH}, address = {Eschborn}, issn = {1867-3147}, pages = {29 -- 33}, year = {2006}, abstract = {Unternehmen sind in der Regel {\"u}berzeugt, dass sie die Bed{\"u}rfnisse ihrer Kunden in den Mittelpunkt stellen. Aber in der direkten Interaktion mit dem Kunden zeigen sie h{\"a}ufig Schw{\"a}chen. Der folgende Beitrag illustriert, wie durch eine konsequente Ausrichtung der Wertsch{\"o}pfungsprozesse auf die zentralen Kundenbed{\"u}rfnisse ein Dreifacheffekt erzielt werden kann: Nachhaltig erh{\"o}hte Kundenzufriedenheit, gesteigerte Effizienz und eine Differenzierung im Wettbewerb.}, language = {de} } @article{BensbergAuthCzarnecki2020, author = {Bensberg, Frank and Auth, Gunnar and Czarnecki, Christian}, title = {Literaturanalyse mit Text Mining}, series = {E-Learning and Education (eleed)}, journal = {E-Learning and Education (eleed)}, number = {13}, editor = {Haake, J{\"o}rg M.}, publisher = {FernUniversit{\"a}t in Hagen}, address = {Hagen}, issn = {1860-7470}, pages = {1 -- 13}, year = {2020}, abstract = {Die Durchf{\"u}hrung einer systematischen Literaturrecherche ist eine zentrale Kompetenz wissenschaftlichen Arbeitens und bildet daher einen festen Ausbildungsbestandteil von Bachelor- und Masterstudieng{\"a}ngen. In entsprechenden Lehrveranstaltungen werden Studierende zwar mit den grundlegenden Hilfsmitteln zur Suche und Verwaltung von Literatur vertraut gemacht, allerdings werden die Potenziale textanalytischer Methoden und Anwendungssysteme (Text Mining, Text Analytics) dabei zumeist nicht abgedeckt. Folglich werden Datenkompetenzen, die zur systemgest{\"u}tzten Analyse und Erschließung von Literaturdaten erforderlich sind, nicht hinreichend ausgepr{\"a}gt. Um diese Kompetenzl{\"u}cke zu adressieren, ist an der Hochschule Osnabr{\"u}ck eine Lehrveranstaltung konzipiert und projektorientiert umgesetzt worden, die sich insbesondere an Studierende wirtschaftswissenschaftlicher Studieng{\"a}nge richtet. Dieser Beitrag dokumentiert die fachliche sowie technische Ausgestaltung dieser Veranstaltung und zeigt Potenziale f{\"u}r die k{\"u}nftige Weiterentwicklung auf.}, language = {de} } @article{HahnHebelManz2022, author = {Hahn, Geogr W. and Hebel, Christoph and Manz, W.}, title = {Die neuen Empfehlungen f{\"u}r Verkehrsnachfragemodellierung im Personenverkehr}, series = {Straßenverkehrstechnik}, volume = {66}, journal = {Straßenverkehrstechnik}, number = {10}, publisher = {Kirschbaum Verlag GmbH}, address = {Bonn}, issn = {0039-2219}, doi = {10.53184/SVT10-2022-1}, pages = {721 -- 726}, year = {2022}, abstract = {Die neu erschienenen „Empfehlungen zum Einsatz von Verkehrsnachfragemodellen f{\"u}r den Personenverkehr" liefern erstmals als Empfehlungspapier der Forschungsgesellschaft f{\"u}r Straßen- und Verkehrswesen einen umfassenden {\"U}berblick zu den verschiedenen Aspekten der Modellierung und geben dem Fachplaner konkrete Hilfestellung f{\"u}r die Konzeption von Nachfragemodellen. Das Empfehlungspapier zielt unter anderem darauf ab, die Erwartungen und das Anspruchsniveau in Hinblick auf Sachgerechtigkeit der Modelle, die erzielbare Modellqualit{\"a}t und den Detaillierungsgrad der Modellaussagen zu harmonisieren.}, language = {de} } @article{EmigHebelSchwark2022, author = {Emig, J. and Hebel, Christoph and Schwark, A.}, title = {Einsatzbereiche f{\"u}r Verkehrsnachfragemodelle}, series = {Straßenverkehrstechnik}, volume = {66}, journal = {Straßenverkehrstechnik}, number = {10}, publisher = {Kirschbaum Verlag GmbH}, address = {Bonn}, issn = {0039-2219}, doi = {10.53184/SVT10-2022-2}, pages = {727 -- 736}, year = {2022}, abstract = {In der Praxis bestehen vielf{\"a}ltige Einsatzbereiche f{\"u}r Verkehrsnachfragemodelle. Mit ihnen k{\"o}nnen Kenngr{\"o}ßen des Verkehrsangebots und der Verkehrsnachfrage f{\"u}r den heutigen Zustand wie auch f{\"u}r zuk{\"u}nftige Zust{\"a}nde bereitgestellt werden, um so die Grundlagen f{\"u}r verkehrsplanerische Entscheidungen zu liefern. Die neuen „Empfehlungen zum Einsatz von Verkehrsnachfragemodellen f{\"u}r den Personenverkehr" (EVNM-PV) (FGSV 2022) veranschaulichen anhand von typischen Planungsaufgaben, welche differenzierten Anforderungen daraus f{\"u}r die Modellkonzeption und -erstellung resultieren. Vor dem Hintergrund der konkreten Aufgabenstellung sowie deren spezifischer planerischer Anforderungen bildet die abzuleitende Modellspezifikation die verabredete Grundlage zwischen Auftraggeber und Modellersteller f{\"u}r die konkrete inhaltliche, fachliche Ausgestaltung des Verkehrsmodells.}, language = {de} } @article{KindmannKrausLaumannetal.2022, author = {Kindmann, Rolf and Kraus, Matthias and Laumann, J{\"o}rg and Vette, Jan}, title = {Verallgemeinerte Berechnungsmethode f{\"u}r in Beton eingespannte Stahlprofile - Einspanntiefen, Tragf{\"a}higkeitsnachweise und Bemessungshilfen}, series = {Stahlbau}, volume = {93}, journal = {Stahlbau}, number = {Early View}, publisher = {Ernst \& Sohn GmbH}, address = {Berlin}, issn = {1437-1049}, doi = {10.1002/stab.202200024}, pages = {1 -- 25}, year = {2022}, abstract = {St{\"u}tzen und Tr{\"a}ger aus Stahlprofilen k{\"o}nnen in Fundamente oder W{\"a}nde aus Stahlbeton einbetoniert werden. Diese Anschl{\"u}sse wirken in der Regel wie Einspannungen, die eine ausreichende Einspanntiefe erfordern. Im Folgenden wird eine verallgemeinerte Berechnungsmethode f{\"u}r in Stahlbetonkonstruktionen eingespannte Stahlprofile aus gewalzten I-Profilen, geschweißten I-Profilen, runden Hohlprofilen, eckigen Hohlprofilen und einzelligen Kastenquerschnitten vorgestellt. F{\"u}r Beanspruchungen infolge einachsiger Biegung um die starke und schwache Profilachse werden der profilabh{\"a}ngige Ansatz der Betondruckspannungen im Einspannbereich und die Ermittlung der Einspanntiefe behandelt. Unter Ber{\"u}cksichtigung der Normalkraft werden an den maßgebenden Stellen Tragf{\"a}higkeitsnachweise f{\"u}r die Stahlprofile gef{\"u}hrt. Als Erg{\"a}nzung zu den Berechnungsformeln werden Bemessungshilfen zur Verf{\"u}gung gestellt, die die Wahl der mitwirkenden Breiten und der Einspanntiefen erleichtert.}, language = {de} } @article{HoerenbaumLaumannProkop2016, author = {H{\"o}renbaum, Christoph and Laumann, J{\"o}rg and Prokop, Ines}, title = {Zur Anwendung des Eurocode 3 Teil 1-2 f{\"u}r die Heißbemessung und Anregungen f{\"u}r dessen Novellierung}, series = {Stahlbau}, volume = {85}, journal = {Stahlbau}, number = {6}, publisher = {Ernst \& Sohn GmbH}, address = {Berlin}, issn = {1437-1049}, doi = {10.1002/stab.201610382}, pages = {429 -- 434}, year = {2016}, abstract = {Die Eurocodes werden bis zum Jahr 2020 im Europ{\"a}ischen Komitee f{\"u}r Normung (CEN), Technisches Komitee TC 250, {\"u}berarbeitet. In Vorbereitung auf die Eurocode-Novellierung haben engagierte Ingenieure im Rahmen der Initiative PraxisRegeln Bau (PRB) die f{\"u}r die praktische Anwendung h{\"a}ufig genutzten Teile des Eurocode 3 untersucht. Mit dem Ziel, die Praxistauglichkeit des Eurocode 3 f{\"u}r die Heißbemessung zu verbessern, wurden die bestehende Norm EN 1993 Teil 1-2 insbesondere in Bezug auf die Anwenderfreundlichkeit analysiert und Vorschl{\"a}ge f{\"u}r die europ{\"a}ische Novellierung erarbeitet. Die Analysen zeigen, dass durch Umstrukturierungen und durch die Einf{\"u}hrung von Tabellen die Verst{\"a}ndlichkeit und Anwenderfreundlichkeit der Regeln f{\"u}r die Heißbemessung bedeutend erh{\"o}ht werden k{\"o}nnen.}, language = {de} } @article{Czarnecki2015, author = {Czarnecki, Christian}, title = {Moderne Telekommunikationsprodukte erfordern standardisierte Gesch{\"a}ftsprozesse}, series = {Wirtschaft und Wissenschaft}, journal = {Wirtschaft und Wissenschaft}, number = {2}, publisher = {Deutsche Telekom AG. Fachhochschule Leipzig}, address = {Leipzig}, pages = {7 -- 7}, year = {2015}, language = {de} } @article{BaringhausGaigall2022, author = {Baringhaus, Ludwig and Gaigall, Daniel}, title = {A goodness-of-fit test for the compound Poisson exponential model}, series = {Journal of Multivariate Analysis}, volume = {195}, journal = {Journal of Multivariate Analysis}, number = {Article 105154}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0047-259X}, doi = {10.1016/j.jmva.2022.105154}, year = {2022}, abstract = {On the basis of bivariate data, assumed to be observations of independent copies of a random vector (S,N), we consider testing the hypothesis that the distribution of (S,N) belongs to the parametric class of distributions that arise with the compound Poisson exponential model. Typically, this model is used in stochastic hydrology, with N as the number of raindays, and S as total rainfall amount during a certain time period, or in actuarial science, with N as the number of losses, and S as total loss expenditure during a certain time period. The compound Poisson exponential model is characterized in the way that a specific transform associated with the distribution of (S,N) satisfies a certain differential equation. Mimicking the function part of this equation by substituting the empirical counterparts of the transform we obtain an expression the weighted integral of the square of which is used as test statistic. We deal with two variants of the latter, one of which being invariant under scale transformations of the S-part by fixed positive constants. Critical values are obtained by using a parametric bootstrap procedure. The asymptotic behavior of the tests is discussed. A simulation study demonstrates the performance of the tests in the finite sample case. The procedure is applied to rainfall data and to an actuarial dataset. A multivariate extension is also discussed.}, language = {en} } @article{KosterScheidweilerTieves2016, author = {Koster, Arie and Scheidweiler, Robert and Tieves, Martin}, title = {A flow based pruning scheme for enumerative equitable coloring algorithms}, series = {A flow based pruning scheme for enumerative equitable coloring algorithms}, journal = {A flow based pruning scheme for enumerative equitable coloring algorithms}, doi = {10.48550/arXiv.1607.08754}, pages = {1 -- 30}, year = {2016}, abstract = {An equitable graph coloring is a proper vertex coloring of a graph G where the sizes of the color classes differ by at most one. The equitable chromatic number is the smallest number k such that G admits such equitable k-coloring. We focus on enumerative algorithms for the computation of the equitable coloring number and propose a general scheme to derive pruning rules for them: We show how the extendability of a partial coloring into an equitable coloring can be modeled via network flows. Thus, we obtain pruning rules which can be checked via flow algorithms. Computational experiments show that the search tree of enumerative algorithms can be significantly reduced in size by these rules and, in most instances, such naive approach even yields a faster algorithm. Moreover, the stability, i.e., the number of solved instances within a given time limit, is greatly improved. Since the execution of flow algorithms at each node of a search tree is time consuming, we derive arithmetic pruning rules (generalized Hall-conditions) from the network model. Adding these rules to an enumerative algorithm yields an even larger runtime improvement.}, language = {en} } @article{BeckenbachScheidweiler2016, author = {Beckenbach, Isabel and Scheidweiler, Robert}, title = {Perfect ƒ-Matchings and ƒ-Factors in Hypergraphs - A Combinatorial Approach}, series = {Discrete Mathematics}, volume = {240}, journal = {Discrete Mathematics}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2192-7782}, doi = {10.1016/j.disc.2017.05.005}, pages = {2499 -- 2506}, year = {2016}, abstract = {We prove characterizations of the existence of perfect ƒ-matchings in uniform mengerian and perfect hypergraphs. Moreover, we investigate the ƒ-factor problem in balanced hypergraphs. For uniform balanced hypergraphs we prove two existence theorems with purely combinatorial arguments, whereas for non-uniform balanced hypergraphs we show that the ƒ-factor problem is NP-hard.}, language = {en} } @article{ScheidweilerTriesch2016, author = {Scheidweiler, Robert and Triesch, Eberhard}, title = {A note on the duality between matchings and vertex covers in balanced hypergraphs}, series = {Journal of Combinatorial Optimization}, volume = {32}, journal = {Journal of Combinatorial Optimization}, number = {2}, publisher = {Springer}, address = {Berlin}, issn = {1573-2886}, doi = {10.1007/s10878-015-9887-5}, pages = {639 -- 644}, year = {2016}, abstract = {We present a new Min-Max theorem for an optimization problem closely connected to matchings and vertex covers in balanced hypergraphs. The result generalizes Kőnig's Theorem (Berge and Las Vergnas in Ann N Y Acad Sci 175:32-40, 1970; Fulkerson et al. in Math Progr Study 1:120-132, 1974) and Hall's Theorem (Conforti et al. in Combinatorica 16:325-329, 1996) for balanced hypergraphs.}, language = {en} } @article{NiedermeyerZhouDursunetal.2016, author = {Niedermeyer, Angela and Zhou, Bei and Dursun, G{\"o}zde and Temiz Artmann, Ayseg{\"u}l and Markert, Bernd}, title = {An examination of tissue engineered scaffolds in a bioreactor}, series = {Proceedings in Applied Mathematics and Mechanics PAMM}, volume = {16}, journal = {Proceedings in Applied Mathematics and Mechanics PAMM}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1617-7061}, doi = {10.1002/pamm.201610038}, pages = {99 -- 100}, year = {2016}, abstract = {Replacement tissues, designed to fill in articular cartilage defects, should exhibit the same properties as the native material. The aim of this study is to foster the understanding of, firstly, the mechanical behavior of the material itself and, secondly, the influence of cultivation parameters on cell seeded implants as well as on cell migration into acellular implants. In this study, acellular cartilage replacement material is theoretically, numerically and experimentally investigated regarding its viscoelastic properties, where a phenomenological model for practical applications is developed. Furthermore, remodeling and cell migration are investigated.}, language = {en} } @article{KilicRaatschenKoerfgenetal.2017, author = {Kilic, S. A. and Raatschen, Hans-J{\"u}rgen and K{\"o}rfgen, B. and Apaydin, N. M. and Astaneh-Asl, A.}, title = {FE Model of the Fatih Sultan Mehmet Suspension Bridge Using Thin Shell Finite Elements}, series = {Arabian Journal for Science and Engineering}, volume = {42}, journal = {Arabian Journal for Science and Engineering}, number = {3}, publisher = {Springer Nature}, issn = {2191-4281}, doi = {10.1007/s13369-016-2316-y}, pages = {1103 -- 1116}, year = {2017}, abstract = {This paper presents the results of an eigenvalue analysis of the Fatih Sultan Mehmet Bridge. A high-resolution finite element model was created directly from the available design documents. All physical properties of the structural components were included in detail, so no calibration to the measured data was necessary. The deck and towers were modeled with shell elements. A nonlinear static analysis was performed before the eigenvalue calculation. The calculated natural frequencies and corresponding mode shapes showed good agreement with the available measured ambient vibration data. The calculation of the effective modal mass showed that nine modes had single contributions higher than 5 \% of the total mass. They were in a frequency range up to 1.2 Hz. The comparison of the results for the torsional modes especially demonstrated the advantage of using thin shell finite elements over the beam modeling approach.}, language = {en} } @article{DantismTakenagaWagneretal.2017, author = {Dantism, Shahriar and Takenaga, Shoko and Wagner, Torsten and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Differential imaging of the metabolism of bacteria and eukaryotic cells based on light-addressable potentiometric sensors}, series = {Electrochimica Acta}, volume = {246}, journal = {Electrochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-4686}, doi = {10.1016/j.electacta.2017.05.196}, pages = {234 -- 241}, year = {2017}, abstract = {A light-addressable potentiometric sensor (LAPS) is a field-effect-based potentiometric sensor with an electrolyte/insulator/semiconductor (EIS) structure, which is able to monitor analyte concentrations of (bio-)chemical species in aqueous solutions in a spatially resolved way. Therefore, it is also an appropriate tool to record 2D-chemical images of concentration variations on the sensor surface. In the present work, two differential, LAPS-based measurement principles are introduced to determine the metabolic activity of Escherichia coli (E. coli) K12 and Chinese hamster ovary (CHO) cells as test microorganisms. Hereby, we focus on i) the determination of the extracellular acidification rate (ΔpH/min) after adding glucose solutions to the cell suspensions; and ii) recording the amplitude increase of the photocurrent (Iph) related to the produced acids from E. coli K12 bacteria and CHO cells on the sensor surface by 2D-chemical imaging. For this purpose, 3D-printed multi-chamber structures were developed and mounted on the planar sensor-chip surface to define four independent compartments, enabling differential measurements with varying cell concentrations. The differential concept allows eliminating unwanted drift effects and, with the four-chamber structures, measurements on the different cell concentrations were performed simultaneously, thus reducing also the overall measuring time.}, language = {en} } @article{JildehKirchnerOberlaenderetal.2017, author = {Jildeh, Zaid B. and Kirchner, Patrick and Oberl{\"a}nder, Jan and Kremers, Alexander and Wagner, Torsten and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef}, title = {FEM-based modeling of a calorimetric gas sensor for hydrogen peroxide monitoring}, series = {physica status solidi a : applications and materials sciences}, journal = {physica status solidi a : applications and materials sciences}, number = {Early View}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201600912}, year = {2017}, abstract = {A physically coupled finite element method (FEM) model is developed to study the response behavior of a calorimetric gas sensor. The modeled sensor serves as a monitoring device of the concentration of gaseous hydrogen peroxide (H2 O2) in a high temperature mixture stream in aseptic sterilization processes. The principle of operation of a calorimetric H2 O2 sensor is analyzed and the results of the numerical model have been validated by using previously published sensor experiments. The deviation in the results between the FEM model and experimental data are presented and discussed.}, language = {en} } @article{ArreolaKeusgenSchoening2017, author = {Arreola, Julio and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Effect of O2 plasma on properties of electrolyte-insulator-semiconductor structures}, series = {physica status solidi a : applications and materials sciences}, volume = {214}, journal = {physica status solidi a : applications and materials sciences}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201700025}, pages = {Artikel 1700025}, year = {2017}, abstract = {Prior to immobilization of biomolecules or cells onto biosensor surfaces, the surface must be physically or chemically activated for further functionalization. Organosilanes are a versatile option as they facilitate the immobilization through their terminal groups and also display self-assembly. Incorporating hydroxyl groups is one of the important methods for primary immobilization. This can be done, for example, with oxygen plasma treatment. However, this treatment can affect the performance of the biosensors and this effect is not quite well understood for surface functionalization. In this work, the effect of O2 plasma treatment on EIS sensors was investigated by means of electrochemical characterizations: capacitance-voltage (C-V) and constant capacitance (ConCap) measurements. After O2 plasma treatment, the potential of the EIS sensor dramatically shifts to a more negative value. This was successfully reset by using an annealing process.}, language = {en} } @article{MiyamotoHayashiSakamotoetal.2017, author = {Miyamoto, Ko-ichiro and Hayashi, Kosuke and Sakamoto, Azuma and Werner, Frederik and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {A high-Q resonance-mode measurement of EIS capacitive sensor by elimination of series resistance}, series = {Sensor and Actuators B: Chemical}, volume = {248}, journal = {Sensor and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2017.03.002}, pages = {1006 -- 1010}, year = {2017}, abstract = {An EIS capacitive sensor is a semiconductor-based potentiometric sensor, which is sensitive to the ion concentration or pH value of the solution in contact with the sensing surface. To detect a small change in the ion concentration or pH, a small capacitance change must be detected. Recently, a resonance-mode measurement was proposed, in which an inductor was connected to the EIS capacitive sensor and the resonant frequency was correlated with the pH value. In this study, the Q factor of the resonant circuit was enhanced by canceling the internal resistance of the reference electrode and the internal resistance of the inductor coil with the help of a bypass capacitor and a negative impedance converter, respectively. 1\% variation of the signal in the developed system corresponded to a pH change of 3.93 mpH, which was about 1/12 of the conventional method, suggesting a better performance in detection of a small pH change.}, language = {en} } @article{WernerMiyamotoWagneretal.2017, author = {Werner, Frederik and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Lateral resolution enhancement of pulse-driven light-addressable potentiometric sensor}, series = {Sensor and Actuators B: Chemical}, volume = {248}, journal = {Sensor and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2017.02.057}, pages = {961 -- 965}, year = {2017}, abstract = {To study chemical and biological processes, spatially resolved determination of the concentrations of one or more analyte species is of distinct interest. With a light-addressable potentiometric sensor (LAPS), chemical images can be created, which visualize the concentration distribution above the sensor plate. One important challenge is to achieve a good lateral resolution in order to detect events that take place in a small and limited region. LAPS utilizes a focused light spot to address the measurement region. By moving this light spot along the semiconductor sensor plate, the concentration distribution can be observed. In this study, we show that utilizing a pulse as light excitation instead of a traditionally used continuously modulated light excitation, the lateral resolution can be improved by a factor of 6 or more.}, language = {en} } @article{SchollMoraisGabrieletal.2017, author = {Scholl, Fabio and Morais, Paulo and Gabriel, Rayla and Sch{\"o}ning, Michael Josef and Siqueira, Jose Roberto, Jr. and Caseli, Luciano}, title = {Carbon nanotubes arranged as smart interfaces in lipid Langmuir-Blodgett films enhancing the enzymatic properties of penicillinase for biosensing applications}, series = {Applied Materials \& Interfaces}, volume = {9}, journal = {Applied Materials \& Interfaces}, number = {36}, publisher = {ACS}, address = {Washington}, issn = {1944-8252}, doi = {10.1021/acsami.7b08095}, pages = {31054 -- 31066}, year = {2017}, abstract = {In this paper, carbon nanotubes (CNTs) were incorporated in penicillinase-phospholipid Langmuir and Langmuir-Blodgett (LB) films to enhance the enzyme catalytic properties. Adsorption of the penicillinase and CNTs at dimyristoylphosphatidic acid (DMPA) monolayers at the air-water interface was investigated by surface pressure-area isotherms, vibrational spectroscopy, and Brewster angle microscopy. The floating monolayers were transferred to solid supports through the LB technique, forming mixed DMPA-CNTs-PEN films, which were investigated by quartz crystal microbalance, vibrational spectroscopy, and atomic force microscopy. Enzyme activity was studied with UV-vis spectroscopy and the feasibility of the supramolecular device nanostructured as ultrathin films were essayed in a capacitive electrolyte-insulator-semiconductor (EIS) sensor device. The presence of CNTs in the enzyme-lipid LB film not only tuned the catalytic activity of penicillinase but also helped conserve its enzyme activity after weeks, showing increased values of activity. Viability as penicillin sensor was demonstrated with capacitance/voltage and constant capacitance measurements, exhibiting regular and distinctive output signals over all concentrations used in this work. These results may be related not only to the nanostructured system provided by the film, but also to the synergism between the compounds on the active layer, leading to a surface morphology that allowed a fast analyte diffusion because of an adequate molecular accommodation, which also preserved the penicillinase activity. This work therefore demonstrates the feasibility of employing LB films composed of lipids, CNTs, and enzymes as EIS devices for biosensing applications.}, language = {en} } @article{TranMottaghyArltKoerferetal.2017, author = {Tran, Linda and Mottaghy, K. and Arlt-K{\"o}rfer, Sabine and Waluga, Christian and Behbahani, Mehdi}, title = {An experimental study of shear-dependent human platelet adhesion and underlying protein-binding mechanisms in a cylindrical Couette system}, series = {Biomedizinische Technik}, volume = {62}, journal = {Biomedizinische Technik}, number = {4}, publisher = {De Gruyter}, address = {Berlin}, issn = {0013-5585}, doi = {10.1515/bmt-2015-0034}, pages = {383 -- 392}, year = {2017}, language = {en} } @article{FigueroaMirandaFengShiuetal.2018, author = {Figueroa-Miranda, Gabriela and Feng, Lingyan and Shiu, Simon Chi-Chin and Dirkzwager, Roderick Marshall and Cheung, Yee-Wai and Tanner, Julian Alexander and Sch{\"o}ning, Michael Josef and Offenh{\"a}usser, Andreas and Mayer, Dirk}, title = {Aptamer-based electrochemical biosensor for highly sensitive and selective malaria detection with adjustable dynamic response range and reusability}, series = {Sensor and Actuators B: Chemical}, volume = {255}, journal = {Sensor and Actuators B: Chemical}, number = {P1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2017.07.117}, pages = {235 -- 243}, year = {2018}, abstract = {Malaria infection remains a significant risk for much of the population of tropical and subtropical areas, particularly in developing countries. Therefore, it is of high importance to develop sensitive, accurate and inexpensive malaria diagnosis tests. Here, we present a novel aptamer-based electrochemical biosensor (aptasensor) for malaria detection by impedance spectroscopy, through the specific recognition between a highly discriminatory DNA aptamer and its target Plasmodium falciparum lactate dehydrogenase (PfLDH). Interestingly, due to the isoelectric point (pI) of PfLDH, the aptasensor response showed an adjustable detection range based on the different protein net-charge at variable pH environments. The specific aptamer recognition allows sensitive protein detection with an expanded detection range and a low detection limit, as well as a high specificity for PfLDH compared to analogous proteins. The specific feasibility of the aptasensor is further demonstrated by detection of the target PfLDH in human serum. Furthermore, the aptasensor can be easily regenerated and thus applied for multiple usages. The robustness, sensitivity, and reusability of the presented aptasensor make it a promising candidate for point-of-care diagnostic systems.}, language = {en} } @article{MoraisGomesSilvaetal.2017, author = {Morais, Paulo V. and Gomes, Vanderley F., Jr. and Silva, Anielle C. A. and Dantas, Noelio O. and Sch{\"o}ning, Michael Josef and Siqueira, Jos{\´e} R., Jr.}, title = {Nanofilm of ZnO nanocrystals/carbon nanotubes as biocompatible layer for enzymatic biosensors in capacitive field-effect devices}, series = {Journal of Materials Science}, volume = {52}, journal = {Journal of Materials Science}, number = {20}, publisher = {Springer}, address = {Berlin}, issn = {1573-4803}, doi = {10.1007/s10853-017-1369-y}, pages = {12314 -- 12325}, year = {2017}, abstract = {The incorporation of nanomaterials that are biocompatible with different types of biological compounds has allowed the development of a new generation of biosensors applied especially in the biomedical field. In particular, the integration of film-based nanomaterials employed in field-effect devices can be interesting to develop biosensors with enhanced properties. In this paper, we studied the fabrication of sensitive nanofilms combining ZnO nanocrystals and carbon nanotubes (CNTs), prepared by means of the layer-by-layer (LbL) technique, in a capacitive electrolyte-insulator-semiconductor (EIS) structure for detecting glucose and urea. The ZnO nanocrystals were incorporated in a polymeric matrix of poly(allylamine) hydrochloride (PAH), and arranged with multi-walled CNTs in a LbL PAH-ZnO/CNTs film architecture onto EIS chips. The electrochemical characterizations were performed by capacitance-voltage and constant capacitance measurements, while the morphology of the films was characterized by atomic force microscopy. The enzymes glucose oxidase and urease were immobilized on film's surface for detection of glucose and urea, respectively. In order to obtain glucose and urea biosensors with optimized amount of sensitive films, we investigated the ideal number of bilayers for each detection system. The glucose biosensor showed better sensitivity and output signal for an LbL PAH-ZnO/CNTs nanofilm with 10 bilayers. On the other hand, the urea biosensor presented enhanced properties even for the first bilayer, exhibiting high sensitivity and output signal. The presence of the LbL PAH-ZnO/CNTs films led to biosensors with better sensitivity and enhanced response signal, demonstrating that the adequate use of nanostructured films is feasible for proof-of-concept biosensors with improved properties that may be employed for biomedical applications.}, language = {en} } @article{LambersBragard2017, author = {Lambers, Andreas and Bragard, Michael}, title = {Kinetische Skulptur - Treffen sich ein E-Techniker und ein K{\"u}nstler ...}, series = {Elektor : learn, design, share}, volume = {48}, journal = {Elektor : learn, design, share}, number = {9}, publisher = {Elektor-Verlag}, address = {Aachen}, issn = {0932-5468}, pages = {78 -- 83}, year = {2017}, abstract = {Die Verbindung der Welten dressierter Elektronen und grenzenloser Kreativit{\"a}t bietet ein großes Potential; zum Beispiel bei modernen Skulpturen, deren Form sich durch Motoren ver{\"a}ndern kann. An der FH Aachen wurde ein solches Projekt verwirklicht: Eine Matrix aus Holzkugeln kann Piktogramme anzeigen, aber auch mathematische Funktionen visualisieren. In diesem Artikel beschreiben wir die clevere Ansteuerung der Motoren.}, language = {de} } @article{RoehlenPilasSchoeningetal.2017, author = {R{\"o}hlen, Desiree and Pilas, Johanna and Sch{\"o}ning, Michael Josef and Selmer, Thorsten}, title = {Development of an amperometric biosensor platform for the combined determination of l-Malic, Fumaric, and l-Aspartic acid}, series = {Applied Biochemistry and Biotechnology}, volume = {183}, journal = {Applied Biochemistry and Biotechnology}, publisher = {Springer}, address = {Berlin}, issn = {1559-0291}, doi = {10.1007/s12010-017-2578-1}, pages = {566 -- 581}, year = {2017}, abstract = {Three amperometric biosensors have been developed for the detection of L-malic acid, fumaric acid, and L -aspartic acid, all based on the combination of a malate-specific dehydrogenase (MDH, EC 1.1.1.37) and diaphorase (DIA, EC 1.8.1.4). The stepwise expansion of the malate platform with the enzymes fumarate hydratase (FH, EC 4.2.1.2) and aspartate ammonia-lyase (ASPA, EC 4.3.1.1) resulted in multi-enzyme reaction cascades and, thus, augmentation of the substrate spectrum of the sensors. Electrochemical measurements were carried out in presence of the cofactor β-nicotinamide adenine dinucleotide (NAD+) and the redox mediator hexacyanoferrate (III) (HCFIII). The amperometric detection is mediated by oxidation of hexacyanoferrate (II) (HCFII) at an applied potential of + 0.3 V vs. Ag/AgCl. For each biosensor, optimum working conditions were defined by adjustment of cofactor concentrations, buffer pH, and immobilization procedure. Under these improved conditions, amperometric responses were linear up to 3.0 mM for L-malate and fumarate, respectively, with a corresponding sensitivity of 0.7 μA mM-1 (L-malate biosensor) and 0.4 μA mM-1 (fumarate biosensor). The L-aspartate detection system displayed a linear range of 1.0-10.0 mM with a sensitivity of 0.09 μA mM-1. The sensor characteristics suggest that the developed platform provides a promising method for the detection and differentiation of the three substrates.}, language = {en} } @article{PilasYaziciSelmeretal.2017, author = {Pilas, Johanna and Yazici, Yasemen and Selmer, Thorsten and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Optimization of an amperometric biosensor array for simultaneous measurement of ethanol, formate, d- and l-lactate}, series = {Electrochimica Acta}, volume = {251}, journal = {Electrochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-4686}, doi = {10.1016/j.electacta.2017.07.119}, pages = {256 -- 262}, year = {2017}, abstract = {The immobilization of NAD+-dependent dehydrogenases, in combination with a diaphorase, enables the facile development of multiparametric sensing devices. In this work, an amperometric biosensor array for simultaneous determination of ethanol, formate, d- and l-lactate is presented. Enzyme immobilization on platinum thin-film electrodes was realized by chemical cross-linking with glutaraldehyde. The optimization of the sensor performance was investigated with regard to enzyme loading, glutaraldehyde concentration, pH, cofactor concentration and temperature. Under optimal working conditions (potassium phosphate buffer with pH 7.5, 2.5 mmol L-1 NAD+, 2.0 mmol L-1 ferricyanide, 25 °C and 0.4\% glutaraldehyde) the linear working range and sensitivity of the four sensor elements was improved. Simultaneous and cross-talk free measurements of four different metabolic parameters were performed successfully. The reliable analytical performance of the biosensor array was demonstrated by application in a clarified sample of inoculum sludge. Thereby, a promising approach for on-site monitoring of fermentation processes is provided.}, language = {en} } @article{AlbannaLuekeSjapicetal.2017, author = {Albanna, Walid and Lueke, Jan Niklas and Sjapic, Volha and Kotliar, Konstantin and Hescheler, J{\"u}rgen and Clusmann, Hans and Sjapic, Sergej and Alpdogan, Serdan and Schneider, Toni and Schubert, Gerrit Alexander and Neumaier, Felix}, title = {Electroretinographic Assessment of Inner Retinal Signaling in the Isolated and Superfused Murine Retina}, series = {Current Eye Research}, journal = {Current Eye Research}, number = {Article in press}, publisher = {Taylor \& Francis}, address = {London}, issn = {1460-2202}, doi = {10.1080/02713683.2017.1339807}, pages = {1 -- 9}, year = {2017}, language = {en} } @article{BalzerStreitHeinze2017, author = {Balzer, Hermann and Streit, Daniel and Heinze, Marcel}, title = {Implikationen der Digitalisierung f{\"u}r den Finanzbereich der Unternehmung und das Rollenbild des CFO}, series = {Betriebswirtschaftliche Implikationen der digitalen Transformation. ZfbF - Schmalenbachs Zeitschrift f{\"u}r betriebswirtschaftliche Forschung, Sonderheft 72}, journal = {Betriebswirtschaftliche Implikationen der digitalen Transformation. ZfbF - Schmalenbachs Zeitschrift f{\"u}r betriebswirtschaftliche Forschung, Sonderheft 72}, number = {72}, editor = {Krause, Stefan}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-658-18751-4_14}, pages = {267 -- 283}, year = {2017}, language = {de} } @article{RietschPfaffenrotBitzetal.2017, author = {Rietsch, Stefan H. G. and Pfaffenrot, Viktor and Bitz, Andreas and Orzada, Stephan and Brunheim, Sascha and Lazik-Palm, Andrea and Theysohn, Jens M. and Ladd, Mark E. and Quick, Harald H. and Kraff, Oliver}, title = {An 8-channel transceiver 7-channel receive RF coil setup for high SNR ultrahigh-field MRI of the shoulder at 7T}, series = {Medical Physics}, journal = {Medical Physics}, number = {Article in press}, publisher = {Wiley}, address = {Hoboken}, issn = {0094-2405}, doi = {10.1002/mp.12612}, year = {2017}, language = {en} } @article{KotliarHauserOrtneretal.2017, author = {Kotliar, Konstantin and Hauser, Christine and Ortner, Marion and Muggenthaler, Claudia and Diehl-Schmid, Janine and Angermann, Susanne and Hapfelmeier, Alexander and Schmaderer, Christoph and Grimmer, Timo}, title = {Altered neurovascular coupling as measured by optical imaging: a biomarker for Alzheimer's disease}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {2045-2322}, doi = {10.1038/s41598-017-13349-5}, pages = {1 -- 11}, year = {2017}, language = {en} } @article{BreuerMangSchoeningetal.2017, author = {Breuer, Lars and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, Ronald and Wagner, Torsten}, title = {Investigation of the spatial resolution of a laser-based stimulation process for light-addressable hydrogels with incorporated graphene oxide by means of IR thermography}, series = {Sensors and Actuators A: Physical}, volume = {268}, journal = {Sensors and Actuators A: Physical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0924-4247}, doi = {10.1016/j.sna.2017.11.031}, pages = {126 -- 132}, year = {2017}, language = {en} } @article{DemmerChowdhurySelmeretal.2017, author = {Demmer, Julius K. and Chowdhury, Nilanjan Pal and Selmer, Thorsten and Ermler, Ulrich and Buckel, Wolfgang}, title = {The semiquinone swing in the bifurcating electron transferring flavoprotein/butyryl-CoA dehydrogenase complex from Clostridium difficile}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, number = {1}, issn = {2041-1723}, doi = {10.1038/s41467-017-01746-3}, pages = {1 -- 10}, year = {2017}, language = {en} } @article{WerkhausenAlbrachtCroninetal.2017, author = {Werkhausen, Amelie and Albracht, Kirsten and Cronin, Neil J. and Meier, Rahel and Mojsen-Moeller, Jens and Seynnes, Olivier R.}, title = {Modulation of muscle-tendon interaction in the human triceps surae during an energy dissipation task}, series = {Journal of Experimental Biology}, volume = {220}, journal = {Journal of Experimental Biology}, number = {22}, issn = {0022-0949}, doi = {10.1242/jeb.164111}, pages = {4141 -- 4149}, year = {2017}, language = {en} } @article{Hoettges2017, author = {H{\"o}ttges, J{\"o}rg}, title = {QKan - Management of drainage system data with QGIS}, series = {Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings}, volume = {17}, journal = {Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings}, number = {Article 13}, pages = {95 -- 100}, year = {2017}, language = {en} } @article{SrivastavaChaharSharmaetal.2017, author = {Srivastava, A. and Chahar, V. and Sharma, V. and Sun, Y. and Bol, R. and Knolle, F. and Schnug, E. and Hoyler, Friedrich and Naskar, N. and Lahiri, S. and Patnaik, R.}, title = {Study of uranium toxicity using low-background gamma-ray spectrometry}, series = {Journal of Radioanalytical and Nuclear Chemistry}, journal = {Journal of Radioanalytical and Nuclear Chemistry}, number = {Online first}, publisher = {Springer}, address = {Berlin}, issn = {1588-2780}, doi = {10.1007/s10967-017-5466-9}, pages = {1 -- 7}, year = {2017}, language = {en} } @article{GaribaldiBegingCaneseetal.2017, author = {Garibaldi, F. and Beging, Stefan and Canese, R. and Carpinelli, G. and Clinthorne, N. and Colilli, S. and Cosentino, L. and Finocchiaro, P. and Giuliani, F. and Gricia, M. and Lucentini, M. and Majewski, S. and Monno, E. and Musico, P. and Santavenere, F. and T{\"o}dter, J. and Wegener, Hans-Peter and Ziemons, Karl}, title = {A novel TOF-PET MRI detector for diagnosis and follow up of the prostate cancer}, series = {European Physical Journal Plus}, volume = {132}, journal = {European Physical Journal Plus}, number = {9}, publisher = {Springer}, address = {Berlin}, issn = {2190-5444}, doi = {10.1140/epjp/i2017-11662-x}, year = {2017}, language = {en} } @article{OrzadaBitzJohstetal.2017, author = {Orzada, Stephan and Bitz, Andreas and Johst, S{\"o}ren and Gratz, Marcel and V{\"o}lker, Maximilian N. and Kraff, Oliver and Abuelhaija, Ashraf and Fiedler, Thomas M. and Solbach, Klaus and Quick, Harald H. and Ladd, Mark E.}, title = {Analysis of an integrated 8-Channel Tx/Rx body array for use as a body coil in 7-Tesla MRI}, series = {Frontiers in Physics}, volume = {5}, journal = {Frontiers in Physics}, number = {Jun}, issn = {2296-424X}, doi = {10.3389/fphy.2017.00017}, year = {2017}, language = {en} } @article{Pfaff2017, author = {Pfaff, Raphael}, title = {Einsatz von offenen Onlinekursen in der Eisenbahnlehre}, series = {Deine Bahn}, journal = {Deine Bahn}, number = {1}, publisher = {Bahn-Fachverlag}, address = {Berlin}, issn = {0948-7263}, pages = {12 -- 16}, year = {2017}, abstract = {Eigene positive Erfahrungen mit Onlinekursen sowie die geringen Studierendenzahlen in der Pr{\"a}senzlehre gaben den Anstoß zu einem Experiment mit einem offenen Onlinekurs auf der Plattform Udemy. Die Erfahrungen sowohl bei der Erstellung und als auch im Lehrbetrieb waren positiv und f{\"u}hrten zu einer neuen Besch{\"a}ftigung mit Inhalten und Lernenden, getrieben durch die Anforderungen der Lernplattform.}, language = {de} } @article{Pfaff2017, author = {Pfaff, Raphael}, title = {Apps f{\"u}r den G{\"u}terwagen? Wie der G{\"u}terwagen 4.0 die effiziente Integration der G{\"u}terbahn in ERTMS erm{\"o}glicht}, series = {Ingenieurspiegel}, journal = {Ingenieurspiegel}, number = {2}, pages = {1 -- 2}, year = {2017}, language = {de} } @article{MiyamotoSekiSutoetal.2018, author = {Miyamoto, Koichiro and Seki, Kosuke and Suto, Takeyuki and Werner, Frederik and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Improved spatial resolution of the chemical imaging sensor with a hybrid illumination that suppresses lateral diffusion of photocarriers}, series = {Sensor and Actuators B: Chemical}, volume = {273}, journal = {Sensor and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2018.07.016}, pages = {1328 -- 1333}, year = {2018}, abstract = {The chemical imaging sensor is a semiconductor-based chemical sensor capable of visualizing pH and ion distributions. The spatial resolution depends on the lateral diffusion of photocarriers generated by illumination of the semiconductor substrate. In this study, two types of optical setups, one based on a bundle of optical fibers and the other based on a binocular tube head, were developed to project a hybrid illumination of a modulated light beam and a ring-shaped constant illumination onto the sensor plate. An improved spatial resolution was realized by the ring-shaped constant illumination, which suppressed lateral diffusion of photocarriers by enhanced recombination due to the increased carrier concentration.}, language = {en} } @article{EckertRudolphGuoetal.2018, author = {Eckert, Alexander and Rudolph, Tobias and Guo, Jiaqi and Mang, Thomas and Walther, Andreas}, title = {Exceptionally Ductile and Tough Biomimetic Artificial Nacre with Gas Barrier Function}, series = {Advanced Materials}, volume = {30}, journal = {Advanced Materials}, number = {32}, publisher = {Wiley-VCH}, doi = {10.1002/adma.201802477}, pages = {Article number 1802477}, year = {2018}, abstract = {Synthetic mimics of natural high-performance structural materials have shown great and partly unforeseen opportunities for the design of multifunctional materials. For nacre-mimetic nanocomposites, it has remained extraordinarily challenging to make ductile materials with high stretchability at high fractions of reinforcements, which is however of crucial importance for flexible barrier materials. Here, highly ductile and tough nacre-mimetic nanocomposites are presented, by implementing weak, but many hydrogen bonds in a ternary nacre-mimetic system consisting of two polymers (poly(vinyl amine) and poly(vinyl alcohol)) and natural nanoclay (montmorillonite) to provide efficient energy dissipation and slippage at high nanoclay content (50 wt\%). Tailored interactions enable exceptional combinations of ductility (close to 50\% strain) and toughness (up to 27.5 MJ m⁻³). Extensive stress whitening, a clear sign of high internal dynamics at high internal cohesion, can be observed during mechanical deformation, and the materials can be folded like paper into origami planes without fracture. Overall, the new levels of ductility and toughness are unprecedented in highly reinforced bioinspired nanocomposites and are of critical importance to future applications, e.g., as barrier materials needed for encapsulation and as a printing substrate for flexible organic electronics.}, language = {en} } @article{LapitanRogatkinPersheyevetal.2018, author = {Lapitan, Denis G. and Rogatkin, Dmitrii A. and Persheyev, Sydulla K. and Kotliar, Konstantin}, title = {False spectra formation in the differential two-channel scheme of the laser Doppler flowmeter}, series = {Biomedizinische Technik}, volume = {63}, journal = {Biomedizinische Technik}, number = {4}, publisher = {De Gruyter}, address = {Berlin}, issn = {0013-5585}, doi = {10.1515/bmt-2017-0060}, pages = {439 -- 444}, year = {2018}, abstract = {Noise in the differential two-channel scheme of a classic laser Doppler flowmetry (LDF) instrument was studied. Formation of false spectral components in the output signal due to beating of electrical signals in the differential amplifier was found out. The improved block-diagram of the flowmeter was developed allowing to reduce the noise.}, language = {en} } @article{RoehlenPilasDahmenetal.2018, author = {R{\"o}hlen, Desiree and Pilas, Johanna and Dahmen, Markus and Keusgen, Michael and Selmer, Thorsten and Sch{\"o}ning, Michael Josef}, title = {Toward a Hybrid Biosensor System for Analysis of Organic and Volatile Fatty Acids in Fermentation Processes}, series = {Frontiers in Chemistry}, journal = {Frontiers in Chemistry}, number = {6}, publisher = {Frontiers}, address = {Lausanne}, doi = {10.3389/fchem.2018.00284}, pages = {Artikel 284}, year = {2018}, abstract = {Monitoring of organic acids (OA) and volatile fatty acids (VFA) is crucial for the control of anaerobic digestion. In case of unstable process conditions, an accumulation of these intermediates occurs. In the present work, two different enzyme-based biosensor arrays are combined and presented for facile electrochemical determination of several process-relevant analytes. Each biosensor utilizes a platinum sensor chip (14 × 14 mm²) with five individual working electrodes. The OA biosensor enables simultaneous measurement of ethanol, formate, d- and l-lactate, based on a bi-enzymatic detection principle. The second VFA biosensor provides an amperometric platform for quantification of acetate and propionate, mediated by oxidation of hydrogen peroxide. The cross-sensitivity of both biosensors toward potential interferents, typically present in fermentation samples, was investigated. The potential for practical application in complex media was successfully demonstrated in spiked sludge samples collected from three different biogas plants. Thereby, the results obtained by both of the biosensors were in good agreement to the applied reference measurements by photometry and gas chromatography, respectively. The proposed hybrid biosensor system was also used for long-term monitoring of a lab-scale biogas reactor (0.01 m³) for a period of 2 months. In combination with typically monitored parameters, such as gas quality, pH and FOS/TAC (volatile organic acids/total anorganic carbonate), the amperometric measurements of OA and VFA concentration could enhance the understanding of ongoing fermentation processes.}, language = {en} } @article{RodriguesMoraisNordietal.2018, author = {Rodrigues, Raul T. and Morais, Paulo V. and Nordi, Cristina S. F. and Sch{\"o}ning, Michael Josef and Siqueira Jr., Jos{\´e} R. and Caseli, Luciano}, title = {Carbon Nanotubes and Algal Polysaccharides To Enhance the Enzymatic Properties of Urease in Lipid Langmuir-Blodgett Films}, series = {Langmuir}, volume = {34}, journal = {Langmuir}, number = {9}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1520-5827}, doi = {10.1021/acs.langmuir.7b04317}, pages = {3082 -- 3093}, year = {2018}, abstract = {Algal polysaccharides (extracellular polysaccharides) and carbon nanotubes (CNTs) were adsorbed on dioctadecyldimethylammonium bromide Langmuir monolayers to serve as a matrix for the incorporation of urease. The physicochemical properties of the supramolecular system as a monolayer at the air-water interface were investigated by surface pressure-area isotherms, surface potential-area isotherms, interfacial shear rheology, vibrational spectroscopy, and Brewster angle microscopy. The floating monolayers were transferred to hydrophilic solid supports, quartz, mica, or capacitive electrolyte-insulator-semiconductor (EIS) devices, through the Langmuir-Blodgett (LB) technique, forming mixed films, which were investigated by quartz crystal microbalance, fluorescence spectroscopy, and field emission gun scanning electron microscopy. The enzyme activity was studied with UV-vis spectroscopy, and the feasibility of the thin film as a urea sensor was essayed in an EIS sensor device. The presence of CNT in the enzyme-lipid LB film not only tuned the catalytic activity of urease but also helped to conserve its enzyme activity. Viability as a urease sensor was demonstrated with capacitance-voltage and constant capacitance measurements, exhibiting regular and distinctive output signals over all concentrations used in this work. These results are related to the synergism between the compounds on the active layer, leading to a surface morphology that allowed fast analyte diffusion owing to an adequate molecular accommodation, which also preserved the urease activity. This work demonstrates the feasibility of employing LB films composed of lipids, CNT, algal polysaccharides, and enzymes as EIS devices for biosensing applications.}, language = {en} } @article{AlbannaKotliarLuekeetal.2018, author = {Albanna, Walid and Kotliar, Konstantin and L{\"u}ke, Jan Niklas and Alpdogan, Serdar and Conzen, Catharina and Lindauer, Ute and Clusmann, Hans and Hescheler, J{\"u}rgen and Vilser, Walthard and Schneider, Toni and Schubert, Gerrit Alexander}, title = {Non-invasive evaluation of neurovascular coupling in the murine retina by dynamic retinal vessel analysis}, series = {Plos one}, volume = {13}, journal = {Plos one}, number = {10}, publisher = {PLOS}, address = {San Francisco}, doi = {10.1371/journal.pone.0204689}, pages = {e0204689}, year = {2018}, abstract = {Background Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC. Methods A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed. Results A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001). Conclusions To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals.}, language = {en} } @article{BarnatKennewegSaldenetal.2016, author = {Barnat, Miriam and Kenneweg, Anne Cornelia and Salden, Peter and Schramm, Christin and Schumann, Marlen}, title = {Das ‚Junge Forum' als Format der Nachwuchsf{\"o}rderung. Ein Beitrag zu Professionalisierung, Netzwerkbildung und kooperativem Lernen}, series = {Lern- und Bildungsprozesse gestalten. Junges Forum Medien und Hochschulentwicklung (JFMH13)}, journal = {Lern- und Bildungsprozesse gestalten. Junges Forum Medien und Hochschulentwicklung (JFMH13)}, publisher = {Waxmann}, address = {M{\"u}nster}, isbn = {978-3-8309-3397-7}, doi = {10.25656/01:16852}, url = {http://nbn-resolving.de/urn:nbn:de:0111-pedocs-168520}, pages = {269 -- 282}, year = {2016}, abstract = {Im Mai 2012 fand in Hamburg erstmals das „Junge Forum Hochschul- und Mediendidaktik" statt, im Juni 2013 folgte in Potsdam die zweite Auflage als „Junges Forum Medien und Hochschulentwicklung". 2014 wurde das dritte „Forum" in Dresden und 2015 das vierte in D{\"u}sseldorf ausgerichtet. Das f{\"u}nfte Forum wird 2016 an der Technischen Universit{\"a}t Darmstadt stattfinden. Initiiert und organisiert wird die Veranstaltung stets von jungen Praktikerinnen und Praktikern sowie Forscherinnen und Forschern mit dem Ziel, dem ‚Nachwuchs' in diesem Bereich ein Austauschforum zu geben. Der vorliegende Artikel stellt die konzeptionellen {\"U}berlegungen vor, die hinter diesen Treffen stehen. Er zeigt im R{\"u}ckgriff auf Netzwerktheorie und aktuelle Diskussionen um Professionalisierung und Third Space, wieso f{\"u}r dieses Format ein aktueller Bedarf besteht, und begr{\"u}ndet dann im R{\"u}ckgriff auf didaktische Konzepte auch die methodische Gestaltung der Veranstaltungen. Unsere These: Das kooperative Lernen in Netzwerken ist ein wichtiger Baustein f{\"u}r die Professionalisierung des hochschul- und mediendidaktischen Nachwuchses.}, language = {de} } @article{TekinAshikagaHorikawaetal.2018, author = {Tekin, Nurettin and Ashikaga, Mitsugu and Horikawa, Atsushi and Funke, Harald}, title = {Enhancement of fuel flexibility of industrial gas turbines by development of innovative hydrogen combustion systems}, series = {Gas for energy}, journal = {Gas for energy}, number = {2}, publisher = {Vulkan-Verlag}, address = {Essen}, pages = {4}, year = {2018}, abstract = {For fuel flexibility enhancement hydrogen represents a possible alternative gas turbine fuel within future low emission power generation, in case of hydrogen production by the use of renewable energy sources such as wind energy or biomass. Kawasaki Heavy Industries, Ltd. (KHI) has research and development projects for future hydrogen society; production of hydrogen gas, refinement and liquefaction for transportation and storage, and utilization with gas turbine / gas engine for the generation of electricity. In the development of hydrogen gas turbines, a key technology is the stable and low NOx hydrogen combustion, especially Dry Low Emission (DLE) or Dry Low NOx (DLN) hydrogen combustion. Due to the large difference in the physical properties of hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for DLE hydrogen combustion. Thus, the development of DLE hydrogen combustion technologies is an essential and challenging task for the future of hydrogen fueled gas turbines. The DLE Micro-Mix combustion principle for hydrogen fuel has been in development for many years to significantly reduce NOx emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized "diffusion-type" flames. The major advantages of this combustion principle are the inherent safety against flashback and the low NOx-emissions due to a very short residence time of the reactants in the flame region of the micro-flames.}, language = {en} } @article{BalakirskiKotliarPaulyetal.2018, author = {Balakirski, Galina and Kotliar, Konstantin and Pauly, Karolin J. and Krings, Laura K. and R{\"u}bben, Albert and Baron, Jens M. and Schmitt, Laurenz}, title = {Surgical Site Infections After Dermatologic Surgery in Immunocompromised Patients: A Single-Center Experience}, series = {Dermatologic Surgery}, journal = {Dermatologic Surgery}, number = {44 (12)}, publisher = {Wolters Kluwer}, doi = {10.1097/DSS.0000000000001615}, pages = {1525 -- 1536}, year = {2018}, abstract = {BACKGROUND Immunosuppression is often considered as an indication for antibiotic prophylaxis to prevent surgical site infections (SSI) while performing skin surgery. However, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. PATIENTS AND METHODS All patients of the Department of Dermatology and Allergology at the University Hospital of RWTH Aachen in Aachen, Germany, who underwent hospitalization for a dermatologic surgery between June 2016 and January 2017 (6 months), were followed up after surgery until completion of the wound healing process. The follow-up addressed the occurrence of SSI and the need for systemic antibiotics after the operative procedure. Immunocompromised patients were compared with immunocompetent patients. The investigation was conducted as a retrospective analysis of patient records. RESULTS The authors performed 284 dermatologic surgeries in 177 patients. Nineteen percent (54/284) of the skin surgery was performed on immunocompromised patients. The most common indications for surgical treatment were nonmelanoma skin cancer and malignant melanomas. Surgical site infections occurred in 6.7\% (19/284) of the cases. In 95\% (18/19), systemic antibiotic treatment was needed. Twenty-one percent of all SSI (4/19) were seen in immunosuppressed patients. CONCLUSION According to the authors' data, immunosuppression does not represent a significant risk factor for SSI after dermatologic surgery. However, larger prospective studies are needed to make specific recommendations on the use of antibiotic prophylaxis while performing skin surgery in these patients. The available data on complications after dermatologic surgery have improved over the past years. Particularly, additional risk factors have been identified for surgical site infections (SSI). Purulent surgical sites, older age, involvement of head, neck, and acral regions, and also the involvement of less experienced surgeons have been reported to increase the risk of the SSI after dermatologic surgeries.1 In general, the incidence of SSI after skin surgery is considered to be low.1,2 However, antibiotics in dermatologic surgeries, especially in the perioperative setting, seem to be overused,3,4 particularly regarding developing antibiotic resistances and side effects. Immunosuppression has been recommended to be taken into consideration as an additional indication for antibiotic prophylaxis to prevent SSI after skin surgery in special cases.5,6 However, these recommendations do not specify the exact dermatologic surgeries, and were not specifically developed for dermatologic surgery patients and treatments, but adopted from other surgical fields.6 According to the survey conducted on American College of Mohs Surgery members in 2012, 13\% to 29\% of the surgeons administered antibiotic prophylaxis to immunocompromised patients to prevent SSI while performing dermatologic surgery on noninfected skin,3 although this was not recommended by Journal of the American Academy of Dermatology Advisory Statement. Indeed, the data on the risk of developing SSI after dermatologic surgery in immunosuppressed patients are limited. However, it is possible that due to the insufficient evidence on the risk of SSI occurrence in this patient group, dermatologic surgeons tend to overuse perioperative antibiotic prophylaxis. To make specific recommendations on the use of antibiotic prophylaxis in immunosuppressed patients in the field of skin surgery, more information about the incidence of SSI after dermatologic surgery in these patients is needed. The aim of this study was to fill this data gap by investigating whether there is an increased risk of SSI after skin surgery in immunocompromised patients compared with immunocompetent patients.}, language = {en} } @article{Olbertz2012, author = {Olbertz, Klaus}, title = {{\"U}bergang von Leiharbeitnehmern bei {\"U}bertragung des Entleiherbetriebs - Entscheidung des EuGH zum Recht des Betriebs{\"u}bergangs}, series = {NWB - Steuer- und Wirtschaftsrecht}, journal = {NWB - Steuer- und Wirtschaftsrecht}, number = {5}, publisher = {NWB-Verlag}, address = {Herne}, issn = {1860-9449}, pages = {398 -- 403}, year = {2012}, abstract = {Wieder einmal hat eine Entscheidung des Europ{\"a}ischen Gerichtshofs (EuGH) das bisherige nationale Verst{\"a}ndnis zu einer Frage des Rechts des Betriebs{\"u}bergangs erheblich ins Wanken gebracht. Bisher entsprach es allgemeiner Auffassung, dass die Arbeitsverh{\"a}ltnisse von Zeit- bzw. Leiharbeitnehmern bei einem Betriebs(teil){\"u}bergang des die Leiharbeitnehmer entleihenden Betriebs nicht auf den Betriebserwerber {\"u}bergehen. Der EuGH hat in der Rechtssache Albron Catering mit Urteil vom 21.10.2010 jedoch entschieden, dass auch Leiharbeitnehmer von einem Betriebs(teil){\"u}bergang erfasst sein k{\"o}nnen. Folglich kann der Erwerber eines Betriebs oder Betriebsteils gem. \S 613a BGB zuk{\"u}nftig verpflichtet sein, auch die an den Betriebsver{\"a}ußerer verliehenen Leiharbeitnehmer zu {\"u}bernehmen. Die Entscheidung des EuGH hat somit zur Konsequenz, dass der {\"U}bergang von Leiharbeitsverh{\"a}ltnissen auf den Erwerber eines Betriebs jedenfalls nicht mehr pauschal ausgeschlossen werden kann. Dies gilt es bei k{\"u}nftigen Betriebs(teil){\"u}bertragungen zu ber{\"u}cksichtigen, um unliebsame {\"U}berraschungen zu vermeiden.}, language = {de} } @article{Olbertz2015, author = {Olbertz, Klaus}, title = {Abschlagsfreie Rente mit 63 - Die wichtigsten Fragestellungen und L{\"o}sungen f{\"u}r die Praxis}, series = {NWB - Steuer- und Wirtschaftsrecht}, journal = {NWB - Steuer- und Wirtschaftsrecht}, number = {15}, publisher = {NWB Verlag}, address = {Herne}, issn = {1860-9449}, pages = {1263 -- 1270}, year = {2015}, language = {de} }