@article{MoseleyHalamekKrameretal.2014, author = {Moseley, Fiona and Halamek, Jan and Kramer, Friederike and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Katz, Evgeny}, title = {An enzyme-based reversible CNOT logic gate realized in a flow system}, series = {Analyst}, volume = {139}, journal = {Analyst}, number = {8}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1364-5528 (E-Journal) ; 0003-2654 (Print)}, doi = {10.1039/C4AN00133H}, pages = {1839 -- 1842}, year = {2014}, abstract = {An enzyme system organized in a flow device was used to mimic a reversible Controlled NOT (CNOT) gate with two input and two output signals. Reversible conversion of NAD⁺ and NADH cofactors was used to perform a XOR logic operation, while biocatalytic hydrolysis of p-nitrophenyl phosphate resulted in an Identity operation working in parallel. The first biomolecular realization of a CNOT gate is promising for integration into complex biomolecular networks and future biosensor/biomedical applications.}, language = {en} } @article{MiyamotoItabashiWagneretal.2014, author = {Miyamoto, Ko-ichiro and Itabashi, Akinori and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {High-speed chemical imaging inside a microfluidic channel}, series = {Sensors and actuators. B: Chemical}, volume = {194}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2013.12.090}, pages = {521 -- 527}, year = {2014}, abstract = {In this study, a high-speed chemical imaging system was developed for visualization of the interior of a microfluidic channel. A microfluidic channel was constructed on the sensor surface of the light-addressable potentiometric sensor (LAPS), on which the ion concentrations could be measured in parallel at up to 64 points illuminated by optical fibers. The temporal change of pH distribution inside the microfluidic channel was recorded at a maximum rate of 100 frames per second (fps). The high frame rate allowed visualization of moving interfaces and plugs in the channel even at a flow velocity of 111 mm/s, which suggests the feasibility of plug-based microfluidic devices for flow-injection analysis (FIA).}, language = {en} } @article{Laack2014, author = {Laack, Walter van}, title = {Nature is much smarter than expected: the Genetic Code is not degenerate}, series = {American journal of humanities and social sciences}, volume = {Vol. 2}, journal = {American journal of humanities and social sciences}, number = {No. 1}, issn = {2329-0781 (Print) ; 2329-079X (Online)}, pages = {10 -- 12}, year = {2014}, abstract = {In any books about genetics it can still today be read that our genetic code is called "degenerate" because it is still believed that 43 = 64 triplets encode the 20 essential amino acids. Indeed we have to assume the inverse law, what means that 34 = 81 exact code positions are really effective for our genetic code and encode the amino acids, compiled to proteins. This very important discovery leads to two completely new results that are limits-overlooking: 1) 34 (=81) genetic code positions mean exactly the same number as there are stable and naturally existing chemical elements in our universe. This famous argument should now lead to some alternative, as well as new fundamental conclusions about our existence. 2) A genetic code positioning system shows that nature is much smarter than expected: mutations are made less dangerous than believed, because they won't be that easily able any more to cause severe damages in the protein-synthesis. This should also lead to some alternative views upon evolution of life.}, language = {en} } @article{SiqueiraMolinnusBegingetal.2014, author = {Siqueira, Jose R. and Molinnus, Denise and Beging, Stefan and Sch{\"o}ning, Michael Josef}, title = {Incorporating a hybrid urease-carbon nanotubes sensitive nanofilm on capacitive field-effect sensors for urea detection}, series = {Analytical chemistry}, volume = {86}, journal = {Analytical chemistry}, number = {11}, publisher = {ACS Publications}, address = {Columbus}, issn = {1520-6882 (E-Journal); 0003-2700 (Print); 0096-4484 (Print)}, doi = {10.1021/ac500458s}, pages = {5370 -- 5375}, year = {2014}, abstract = {The ideal combination among biomolecules and nanomaterials is the key for reaching biosensing units with high sensitivity. The challenge, however, is to find out a stable and sensitive film architecture that can be incorporated on the sensor's surface. In this paper, we report on the benefits of incorporating a layer-by-layer (LbL) nanofilm of polyamidoamine (PAMAM) dendrimer and carbon nanotubes (CNTs) on capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors for detecting urea. Three sensor arrangements were studied in order to investigate the adequate film architecture, involving the LbL film with the enzyme urease: (i) urease immobilized directly onto a bare EIS [EIS-urease] sensor; (ii) urease atop the LbL film over the EIS [EIS-(PAMAM/CNT)-urease] sensor; and (iii) urease sandwiched between the LbL film and another CNT layer [EIS-(PAMAM/CNT)-urease-CNT]. The surface morphology of all three urea-based EIS biosensors was investigated by atomic force microscopy (AFM), while the biosensing abilities were studied by means of capacitance-voltage (C/V) and dynamic constant-capacitance (ConCap) measureaments at urea concentrations ranging from 0.1 mM to 100 mM. The EIS-urease and EIS-(PAMAM/CNT)-urease sensors showed similar sensitivity (∼18 mV/decade) and a nonregular signal behavior as the urea concentration increased. On the other hand, the EIS-(PAMAM/CNT)-urease-CNT sensor exhibited a superior output signal performance and higher sensitivity of about 33 mV/decade. The presence of the additional CNT layer was decisive to achieve a urea based EIS sensor with enhanced properties. Such sensitive architecture demonstrates that the incorporation of an adequate hybrid enzyme-nanofilm as sensing unit opens new prospects for biosensing applications using the field-effect sensor platform.}, language = {en} } @article{MuribYeapMartensetal.2014, author = {Murib, Mohammed Sharif and Yeap, Weng-Siang and Martens, Daan and Bienstman, Peter and Ceuninck, Ward de and Grinsven, Bart van and Sch{\"o}ning, Michael Josef and Michiels, Luc and Haenen, Ken and Ameloot, Marcel and Serpeng{\"u}zel, Ali and Wagner, Patrick}, title = {Photonic detection and characterization of DNA using sapphire microspheres}, series = {Journal of biomedical optics}, volume = {19}, journal = {Journal of biomedical optics}, number = {9}, publisher = {SPIE}, address = {Bellingham}, issn = {1560-2281 (E-Journal); 1083-3668 (Print)}, doi = {10.1117/1.JBO.19.9.097006}, pages = {097006}, year = {2014}, abstract = {A microcavity-based deoxyribonucleic acid (DNA) optical biosensor is demonstrated for the first time using synthetic sapphire for the optical cavity. Transmitted and elastic scattering intensity at 1510 nm are analyzed from a sapphire microsphere (radius 500  μm, refractive index 1.77) on an optical fiber half coupler. The 0.43 nm angular mode spacing of the resonances correlates well with the optical size of the sapphire sphere. Probe DNA consisting of a 36-mer fragment was covalently immobilized on a sapphire microsphere and hybridized with a 29-mer target DNA. Whispering gallery modes (WGMs) were monitored before the sapphire was functionalized with DNA and after it was functionalized with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The shift in WGMs from the surface modification with DNA was measured and correlated well with the estimated thickness of the add-on DNA layer. It is shown that ssDNA is more uniformly oriented on the sapphire surface than dsDNA. In addition, it is shown that functionalization of the sapphire spherical surface with DNA does not affect the quality factor (Q≈104) of the sapphire microspheres. The use of sapphire is especially interesting because this material is chemically resilient, biocompatible, and widely used for medical implants.}, language = {en} } @article{FrotscherStaat2014, author = {Frotscher, Ralf and Staat, Manfred}, title = {Stresses produced by different textile mesh implants in a tissue equivalent}, series = {BioNanoMaterials}, volume = {15}, journal = {BioNanoMaterials}, number = {1-2}, publisher = {De Gruyter}, address = {Berlin}, issn = {2191-4672 (E-Journal); 2193-066X (E-Journal); 0011-8656 (Print); 1616-0177 (Print); 2193-0651 (Print)}, doi = {10.1515/bnm-2014-0003}, pages = {25 -- 30}, year = {2014}, abstract = {Two single-incision mini-slings used for treating urinary incontinence in women are compared with respect to the stresses they produce in their surrounding tissue. In an earlier paper we experimentally observed that these implants produce considerably different stress distributions in a muscle tissue equivalent. Here we perform 2D finite element analyses to compare the shear stresses and normal stresses in the tissue equivalent for the two meshes and to investigate their failure behavior. The results clearly show that the Gynecare TVT fails for increasing loads in a zipper-like manner because it gradually debonds from the surrounding tissue. Contrary to that, the tissue at the ends of the DynaMesh-SIS direct may rupture but only at higher loads. The simulation results are in good agreement with the experimental observations thus the computational model helps to interpret the experimental results and provides a tool for qualitative evaluation of mesh implants.}, language = {en} } @article{GuoMiyamotoWagneretal.2014, author = {Guo, Yuanyuan and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Device simulation of the light-addressable potentiometric sensor for the investigation of the spatial resolution}, series = {Sensors and actuators B: Chemical}, volume = {204}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.08.016}, pages = {659 -- 665}, year = {2014}, abstract = {As a semiconductor-based electrochemical sensor, the light-addressable potentiometric sensor (LAPS) can realize two dimensional visualization of (bio-)chemical reactions at the sensor surface addressed by localized illumination. Thanks to this imaging capability, various applications in biochemical and biomedical fields are expected, for which the spatial resolution is critically significant. In this study, therefore, the spatial resolution of the LAPS was investigated in detail based on the device simulation. By calculating the spatiotemporal change of the distributions of electrons and holes inside the semiconductor layer in response to a modulated illumination, the photocurrent response as well as the spatial resolution was obtained as a function of various parameters such as the thickness of the Si substrate, the doping concentration, the wavelength and the intensity of illumination. The simulation results verified that both thinning the semiconductor substrate and increasing the doping concentration could improve the spatial resolution, which were in good agreement with known experimental results and theoretical analysis. More importantly, new findings of interests were also obtained. As for the dependence on the wavelength of illumination, it was found that the known dependence was not always the case. When the Si substrate was thick, a longer wavelength resulted in a higher spatial resolution which was known by experiments. When the Si substrate was thin, however, a longer wavelength of light resulted in a lower spatial resolution. This finding was explained as an effect of raised concentration of carriers, which reduced the thickness of the space charge region. The device simulation was found to be helpful to understand the relationship between the spatial resolution and device parameters, to understand the physics behind it, and to optimize the device structure and measurement conditions for realizing higher performance of chemical imaging systems.}, language = {en} } @article{KhaydukovaZadorozhnayaKirsanovetal.2014, author = {Khaydukova, M. M. and Zadorozhnaya, O. A. and Kirsanov, D. O. and Iken, Heiko and Rolka, David and Sch{\"o}ning, Michael Josef and Babain, V. A. and Vlasov, Yu. G. and Legin, A. V.}, title = {Multivariate processing of atomic-force microscopy images for detection of the response of plasticized polymeric membranes}, series = {Russian journal of applied chemistry}, volume = {87}, journal = {Russian journal of applied chemistry}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {1608-3296 (E-Journal); 1070-4272 (Print)}, doi = {10.1134/S1070427214030112}, pages = {307 -- 314}, year = {2014}, abstract = {The possibility of using the atomic-force microscopy as a method for detection of the analytical signal from plasticized polymeric sensor membranes was analyzed. The surfaces of cadmium-selective membranes based on two polymeric matrices were examined. The digital images were processed with multivariate image analysis techniques. A correlation was found between the surface profile of an ion-selective membrane and the concentration of the ion in solution.}, language = {en} } @article{MuellerHirschfeldLambertzetal.2014, author = {M{\"u}ller, Martin and Hirschfeld, Julian and Lambertz, Rita and Schulze Lohoff, Andreas and Lustfeld, Hans and Pfeifer, Heinz and Reißel, Martin}, title = {Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks}, series = {Journal of power sources}, volume = {272}, journal = {Journal of power sources}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2755 (E-Journal); 0378-7753 (Print)}, doi = {10.1016/j.jpowsour.2014.08.045}, pages = {225 -- 232}, year = {2014}, abstract = {In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents.}, language = {en} } @article{Laack2014, author = {Laack, Walter van}, title = {Nahtoderfahrungen aus medizinischer Sicht}, series = {Deutsche medizinische Wochenschrift : DMW}, volume = {Jg. 139}, journal = {Deutsche medizinische Wochenschrift : DMW}, number = {H. 51/52}, publisher = {Thieme}, address = {Stuttgart}, issn = {1439-4413 (E-Journal); 0012-0472 (Print); 1437-5982 (Print)}, doi = {10.1055/s-0034-1387363}, pages = {2651 -- 2654}, year = {2014}, abstract = {Nah- versus Nachtoderfahrungen Nahtoderfahrungen (NTE) sind ein Ph{\"a}nomen aus der Kategorie „außergew{\"o}hnliche Bewusstseinserfahrungen". Sie treten in unmittelbarer N{\"a}he des eigenen Todes auf. Oft, aber nicht immer, handelt es sich dabei um Erfahrungen von Personen, die durch {\"a}rztliche Maßnahmen wiederbelebt wurden und sp{\"a}ter davon berichten (NTE-ler). Jedoch kommen solche Ph{\"a}nomene auch bei Menschen vor, die w{\"a}hrend einer schweren Erkrankung eine lebensbedrohliche Krise haben, hiervon aber spontan genesen. Den NTE {\"a}hnlich sind auch sogenannte Nachtod-erfahrungen sowie spontane Erlebnisse, die im Rahmen anderer außergew{\"o}hnlicher Stresssituationen auftreten. Von Nachtoderfahrungen spricht man, wenn die Betroffenen anl{\"a}sslich des Todes von geliebten Angeh{\"o}rigen oder Freunden Erlebnisse haben, die inhaltlich ebenfalls, zumindest aber teilweise, denen von NTE entsprechen. Nachtoderfahrungen sowie spontane NTE-{\"a}hnliche Erlebnisse unterscheiden sich jedoch von den echten NTE zumeist sowohl quantitativ als auch qualitativ. Unter einem quantitativen Unterschied versteht man in diesem Zusammenhang eine in der Regel geringer ausgepr{\"a}gte Komplexit{\"a}t, als sie sehr vielen NTE zu eigen ist. Da sich aber auch viele NTE selbst bez{\"u}glich ihrer Komplexit{\"a}t unterscheiden, ist der Hauptunterschied qualitativer Natur: Echte NTE besitzen gegen{\"u}ber den anderen hier erw{\"a}hnten Ph{\"a}nomenen eine gr{\"o}ßere inhaltliche und emotionale Tiefe. Sie begleiten die Betroffenen anschließend ein Leben lang - zumeist mit positiven, in Einzelf{\"a}llen aber auch mit negativen Folgen, die bis zu einem sp{\"a}teren Suizid reichen k{\"o}nnen. Die genannten außergew{\"o}hnlichen Bewusstseinsph{\"a}nomene lassen sich in ihrer Gesamtheit bei rund 5 \% der Bev{\"o}lkerung finden. NTE im Speziellen haben hiervon einen durchaus bedeutenden Anteil. Je nach Studie geben zwischen 18 \% und 40 \% aller Personen, die reanimiert wurden, an, w{\"a}hrenddessen eine NTE erlebt zu haben. Dass nicht alle eine solche Erfahrung machen, wird von Kritikern gern dahingehend interpretiert, NTE seien rein physiologischer und keineswegs spiritueller Natur. Jedoch sollte man bedenken, dass im Fall einer rein neurophysiologischen Grundlage von NTE dann bei jedem ein solches Ph{\"a}nomen zu erwarten w{\"a}re, so wie beispielsweise auch die Symptome einer Hypoglyk{\"a}mie im Wesentlichen immer dieselben sind.}, language = {de} }