bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variable electric fields for high throughput electroporation protocol design in curvilinear coordinates
Authors: Fernand Francois , Rubinsky Liel , Golberg Alex , Rubinsky Boris 
Published: March 2012

AbstractThe mathematical solution to the electric field equation in cylindrical coordinates, has suggested to us a new experimental methodology and device for reducing experimental effort in designing electroporation protocols. Using a new cylindrical electroporation system, we show, with an Escherichia coli cell model, how key electroporation parameters emerge precisely from single experiments rather than through interpolation from numerous experiments in the conventional Cartesian electroporation system. Biotechnol. Bioeng. 2012; 109:2168–2171. © 2012 Wiley Periodicals, Inc.
Influence of Vanadium or Cobalt Oxides on the CO Oxidation Behavior of Au/MOx/CeO2–Al2O3 Systems
Authors: Reina Tomás Ramírez , Moreno Andrea Álvarez , Ivanova Svetlana , Odriozola José Antonio , Centeno Miguel Angel 
Published: March 2012

AbstractA series of V2O5‐ and Co3O4‐modified ceria/alumina supports and their corresponding gold catalysts were synthesized and their catalytic activities evaluated in the CO oxidation reaction. V2O5‐doped solids demonstrated a poor capacity to abate CO, even lower than that of the original ceria/alumina support, owing to the formation of CeVO4. XRD, Raman spectroscopy, and H2‐temperature programmed reduction studies confirmed the presence of this stoichiometric compound, in which cerium was present as Ce3+ and its redox properties were avoided. Co3O4‐doped supports showed a high activity in CO oxidation at subambient temperatures. The vanadium oxide‐doped gold catalysts were not efficient because of gold particle agglomeration and CeVO4 formation. However, the gold–cobalt oxide–ceria/alumina catalysts demonstrated a high capacity to abate CO at and below room temperature. Total conversion was achieved at −70 °C. The calculated apparent activation energy values revealed a theoretical optimum loading of a half‐monolayer.
On the Lifetime of the Transients (NP)(CH3)n (NP=Ag0, Au0, TiO2 Nanoparticles) Formed in the Reactions Between Methyl Radicals and Nanoparticles Suspended in Aqueous Solutions
Authors: Bar‐Ziv Ronen , Zilbermann Israel , Oster‐Golberg Olga , Zidki Tomer , Yardeni Guy , Cohen Haim , Meyerstein Dan 
Published: March 2012

AbstractMethyl radicals react in fast reactions, with rate constants k>1×108 M−1 s−1, with Au0, Ag0 and TiO2 nanoparticles (NPs) dispersed in aqueous solutions to form intermediates, (NP)(CH3)n, in which the methyl groups are covalently bound to the NPs. These intermediates decompose to form ethane. As n≥2 is required for the formation of C2H6, the minimal lifetime (τ) of the methyls bound to the NPs, (NP)CH3, can be estimated from the rate of production of the CH3. radicals and the NPs concentration. The results obtained in this study, using a very low dose rate γ‐source for NP=Ag0, Au0, and TiO2 point out that τ of these intermediates is surprisingly long, for example, ≥8 and ≥188 sec for silver and gold, respectively. These data point out that the NPC bond dissociation energies are ≥70 kJ mol−1. Under low rates of production of CH3., that is, when the rate of formation of ethane is very low, other reactions may occur, consequently the mechanism proposed is “broken”. This is observed in the present study only for TiO2 NPs. These results have to be considered whenever alkyl radicals are formed near surfaces. Furthermore, the results point out that the rate of reaction of methyl radicals with (NP)(CH3)n depends on n, that is, the number of methyl radicals bound to the NPs affect the properties of the NPs.
ChemInform Abstract: Chemistry and Physics of a Single Atomic Layer: Strategies and Challenges for Functionalization of Graphene and Graphene‐Based Materials
Authors: Yan Liang , Zheng Yue Bing , Zhao Feng , Li Shoujian , Gao Xingfa , Xu Bingqian , Weiss Paul S. , Zhao Yuliang 
Published: March 2012

AbstractReview: 315 refs.
Integration of Organic Fluorophores in the Surface of Polymer‐Coated Colloidal Nanoparticles for Sensing the Local Polarity of the Environment
Authors: Amin Faheem , Yushchenko Dmytro A. , Montenegro Jose M. , Parak Wolfgang J. 
Published: March 2012

AbstractInorganic hydrophobically capped NPs such as quantum dots, superparamagnetic iron oxide, or gold nanoparticles can be modified to make them water‐soluble by their embedding in an amphiphilic polymer shell. This polymer shell can be prefunctionalized by the integration of organic fluorophores, which allows the observation of the nanoparticles with fluorescence based techniques. The fluorophore could be either located more in the hydrophobic part of the inner polymer shell, or on the hydrophilic surface pointing towards solution. Herein we prepared gold nanoparticles decorated with the organic fluorophore FE, 4′‐N,N‐diethylamino‐3‐hydroxyflavone (FE), which possesses fluorescence sensitive to the polarity and hydrogen‐bonding properties of the surrounding local environment. Based on the response of FE in the polymer shell to isopropanol, and CTAB compared to the response of free FE we conclude that the FE fluorophore is situated within the inner polymer shell. Nevertheless the fluorophore in the polymer shell can still sense polarity changes in solution.
Immobilised Lipase on Structured Supports Containing Covalently Attached Ionic Liquids for the Continuous Synthesis of Biodiesel in scCO2
Authors: Lozano Pedro , García‐Verdugo Eduardo , Bernal Juana M. , Izquierdo Diana F. , Burguete M. Isabel , Sánchez‐Gómez Gregorio , Luis Santiago V. 
Published: March 2012

AbstractDifferent nanostructured supports, based on 1‐decyl‐2‐methyimidazolium cations covalently attached to a polystyrene divinylbenzene porous matrix, were used as carriers to immobilise Candida antarctica lipase B. The suitability of these immobilised lipase derivatives for the synthesis of biodiesel (methyl oleate) by the methanolysis of triolein has been tested in both tert‐butanol and supercritical (sc)CO2 (18 MPa, 45 °C) as reaction media. The use of modified supports with low ionic‐liquid loading covalently attached to the main polymeric backbone chains provide structured materials that led to the best biodiesel yields (up to 95 %) and operational stability (85 % biodiesel yield after 45 cycles of 8–4 h) in scCO2 (45 °C, 18 MPa). The presence of tert‐butanol as an inert cosolvent in the scCO2 phase at the same concentration as triolein was key to avoid poisoning the biocatalyst through the blockage of its active sites by the polar byproduct (glycerol) produced in the biodiesel synthesis.
Performance analysis of time division broadcast protocol with incremental relaying and symmetric users
Authors: Xu Kun , Gao Yuanyuan , Yi Xiaoxin , Zang Guozhen , Sha Nan 
Published: March 2012

SUMMARYThis paper investigates two‐way relaying with direct link transmission. We propose to combine incremental relaying (IR) with the time division broadcast protocol (TDBC) to form a new scheme, termed TDBC‐IR, to increase the spectral efficiency of TDBC. Assuming half‐duplex decode‐and‐forward relaying, the performance of three protocols, that is, TDBC, TDBC‐IR, and physical‐layer network coding (PNC), are studied and compared, in terms of outage probability, expected rate (ER), and diversity‐multiplexing tradeoff. First, we reveal that the outage probability performance of TDBC‐IR is the same as that of TDBC and better than that of PNC. Second, we compare the ER and diversity‐multiplexing tradeoff performance of the three protocols based on the derived outage probability. The numerical results reveal that (1) the ER of TDBC‐IR is greater than that of TDBC and PNC in the whole signal‐to‐noise ratio (SNR) region, that is TDBC‐IR has improved spectral efficiency performance; (2) the ER performance of TDBC is better than PNC in the low SNR region but worse in the high SNR region; (3) the maximum achievable diversity order of TDBC‐IR and TDBC are both two whereas that of PNC is one; (4) the maximum achievable multiplexing gain of TDBC‐IR is one, which is better than TDBC (its maximum achievable is 2/3) and achieves the maximum of PNC (its maximum achievable is one). Copyright © 2012 John Wiley & Sons, Ltd.
Commentary on: ‘Universal school‐based prevention programmes for alcohol misuse in young people’
Authors: Newton Nicola C. , Teesson Maree 
Published: March 2012

AbstractThis is a commentary on a Cochrane review, published in this issue of EBCH, first published as: Foxcroft DR, Tsertsvadze A. Universal school‐based prevention programmes for alcohol misuse in young people. Cochrane Database of Systematic Reviews 2011, Issue 5. Art. No.: CD009113. DOI: 10.1002/14651858.CD009113.Further information for this Cochrane review is available in this issue of EBCH in the accompanying Summary article. Copyright © 2012 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration
Commentary on: ‘Kangaroo mother care to reduce morbidity and mortality in low‐birth‐weight infants’
Authors: Warnock Fay F. , Castral Thaila 
Published: March 2012

AbstractThis is a commentary on a Cochrane review, published in this issue of EBCH, first published as: Conde‐Agudelo A, Belizán JM, Diaz‐Rossello J. Kangaroo mother care to reduce morbidity and mortality in low‐birth‐weight infants. Cochrane Database of Systematic Reviews 2011, Issue 3. Art. No.: CD002771. DOI: 10.1002/14651858.CD002771.pub2.Further information for this Cochrane review is available in this issue of EBCH in the accompanying Summary article. Copyright © 2012 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration
Untersuchungen zur hydraulischen Stützung mit Polymerlösungen
Authors: Lesemann Henning , Vogt Norbert 
Published: March 2012

AbstractPolymere Lösungen stellen eine technisch und wirtschaftlich interessante Alternative zu den bislang üblicherweise verwendeten Bentonitsuspensionen für die hydraulische Stützung von Bohrlöchern und Schlitzen dar und werden im Ausland seit Jahren zunehmend eingesetzt. Die in Frage kommenden Polymerlösungen weisen im Gegensatz zu Bentonitsuspensionen praktisch keine Fließgrenze auf, weshalb sich das Eindring‐ und Stützverhalten wesentlich unterscheidet und die bekannten Nachweise der Schlitzstabilität nicht anwendbar sind. Durch ein Forschungsvorhaben am Zentrum Geotechnik der Technischen Universität München sollten die Kenntnisse über das Verfahren und dessen Anwendbarkeit erweitert und dokumentiert werden, um die Planung und den sicheren und verantwortungsvollen Einsatz in der Praxis zu erleichtern. Hierzu wurden die theoretischen Grundlagen zur Strömung solcher nicht‐newtonscher Fluide im Lockergestein aufbereitet und Möglichkeiten der Modellierung diskutiert. In Laborversuchen wurden das Strömungsverhalten der Lösungen und die Parameterbestimmung für die Modelle untersucht. In Feldversuchen wurden fünf Bohrpfähle polymergestützt und ein Vergleichspfahl bentonitgestützt hergestellt und dabei auch weitere baupraktische Fragestellungen untersucht. Außerdem wurden Hinweise zum Nachweisverfahren gegeben und die Umweltverträglichkeit des Verfahrens betrachtet.Investigations into hydraulic support using polymeric solutions Polymer solutions turn out to be a technically and economically promising alternative to the so far commonly used bentonite suspensions for the hydraulic support of boreholes or diaphragm wall trenches and have been used increasingly abroad. As a consequence of the almost non‐existent yield strengths of the applicable polymer solutions, their flow and support characteristics differ considerably from those of bentonite suspensions and established stability analyses cannot be adopted. A research project at the Zentrum Geotechnik, Technische Universität München, was carried out to improve and document the knowledge of this method and its applicability. Therefore, basic principles of the flow of such non‐Newtonian fluids in soil were recapitulated and options for modelling were discussed. The flow behaviour of the polymeric solutions and the determination of model parameters were studied in laboratory tests. In field tests, five bored piles were completed under polymeric support and one reference pile under bentonite support. In the course of these tests, further issues of relevance for construction practice were investigated. Finally, details of the stability analyses were specified and the environmental compatibility of the construction method was examined.
Stand der europäischen und deutschen geotechnischen Normen
Authors: Schuppener Bernd , Eitner Volker , Linder Wolf‐Rüdiger , Richter Thomas , Ruppert Franz‐Reinhard , Zurborg Jens 
Published: March 2012

AbstractIm Juli 2012 sollen die Eurocodes bauaufsichtlich eingeführt werden. Das ist Anlass, die wesentlichen Neuerungen in den beiden Teilen des Eurocodes 7: Entwurf, Bemessung und Berechnung in der Geotechnik – Teil 1: Allgemeine Regeln (EC 7‐1) und Teil 2: Erkundung und Untersuchung des Baugrunds (EC7‐2) sowie in den beiden Ergänzungsnormen DIN 1054:2010‐12 und DIN 4020:2010‐12 vorzustellen. Da die Einführung des EC 7‐1 eine Reihe von Anpassungen bei den geotechnischen Berechnungsnormen erforderlich machte und darüber hinaus schon seit Jahren die Herstellungsnormen des Grundbaus auf europäischer Ebene weiterentwickelt werden, wird ebenfalls über den Stand dieser Normen und die weitere Normungsarbeit berichtet.State of the German and European geotechnical standards In July 2012 the Eurocodes will officially be implemented by the German authorities. For this reason the most important innovations of both parts of Eurocode 7: Geotechnical design – Part 1: General rules (EC 7‐1) and Part 2: Ground investigation and testing (EC7‐2) will be presented as well as the supplementary rules of DIN 1054:2010‐12 und DIN 4020:2010‐12. The implementation of EC 7‐1 necessitated some adjustments in the standards for geotechnical calculations and as the standards for execution of special geotechnical works have been developed very significantly in the past years they are also included in the report.
Healthcare financing in Syria: satisfaction with the current system and the role of national health insurance—a qualitative study of householders' views
Authors: Mershed Mania , Busse Reinhard , van Ginneken Ewout 
Published: March 2012

ABSTRACTThis study aims to identify the satisfaction with the current public health system and health benefit schemes, examine willingness to participate in national health insurance and review expectations and preferences of national health insurance. To this end, qualitative semi‐structured interviews were carried out with 19 Syrian householders. Our results show that a need for health reform exists and that Syrian people are willing to support a national health insurance scheme if some key issues are properly addressed. Funding of the scheme is a major concern and should take into account the ability to pay and help the poor. In addition, waiting times should be shortened and sufficient coverage guaranteed. On the whole, the people would support a national health insurance with national pooling and purchasing under a public set‐up, but important concerns of such a system regarding corruption and inefficiency were voiced too. Installing a quasi non‐governmental organisation as manager of the insurance system under the stewardship of the Ministry of Health could provide a compromise acceptable to the people. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of Functionalized Polytriazoles via One‐Pot Sequential Copper‐Catalyzed Azide–Alkyne [3+2] Cycloaddition and Atom Transfer Radical Addition (ATRA)
Authors: Ricardo Carolynne L. , Pintauer Tomislav 
Published: March 2012

AbstractAs a continuing effort of expanding the scope of catalyst regeneration in the presence of environmentally benign reducing agents, one‐pot sequential azide–alkyne [3+2] cycloaddition and atom transfer radical addition (ATRA) reactions were performed via in situ reduction of copper(II) by ascorbic acid. The formation of functionalized triazoles was achieved utilizing a ligand‐free catalytic system for the cycloaddition between tripropargylamine and vinylbenzyl azide and subsequent addition of tris(2‐pyridyl)methylamine (TPMA) ligand in the ATRA step. With this strategy, reactions with carbon tetrachloride and carbon tetrabromide proceeded efficiently providing the desired triazoles in nearly quantitative yields (>90 %) using 10 mol % of copper. Sequential azide–alkyne [3+2] cycloaddition and ATRA reactions were also extended to less active alkyl halides such as methyl trichloroacetate, methyl dichloroacetate and dichloroacetonitrile. The corresponding products were obtained in modest yields (50–80 %). The presented methodology enables efficient synthesis of functionalized polytriazoles, which could have a potential use as chelating agents for a variety of transition metals.
Internet Adoption by Travel Agents: a Case of Egypt
Authors: Abou‐Shouk Mohamed , Lim Wai Mun , Megicks Phil 
Published: March 2012

ABSTRACTCurrent collaborative and rapid developments in tourism and information and communication technologies (ICTs) make it difficult to imagine that tourism existed before ICTs. Communication technology is one main reason for the existence of the Internet. Travel agents (TAs) are among service providers whom their Internet adoption could be the best marketing device for their business and a tool for their competitive advantages. The study explores the Internet adoption of the Egyptian TAs, patterns of usage and perceived benefits and barriers of e‐commerce adoption. It is found that the majority of TAs use the Internet to provide TA's information, find out about customers and competitors. Sales and revenue growth, increasing competitive advantages and marketing activities are the agents’ perceived benefits of adopting e‐commerce. Limited resources, unskilled labour, lack of readiness of public infrastructure and customers are among the main obstacles for not adopting the Internet technologies. Copyright © 2012 John Wiley & Sons, Ltd.
Measurement of 129Xe gas apparent diffusion coefficient anisotropy in an elastase‐instilled rat model of emphysema
Authors: Boudreau Mathieu , Xu Xiaojun , Santyr Giles E. 
Published: March 2012

AbstractHyperpolarized noble gas (3He and 129Xe) apparent diffusion coefficient (ADC) measurements have shown remarkable sensitivity to microstructural (i.e., alveolar) changes in the lung, particularly emphysema. The ADC of hyperpolarized noble gases depends strongly on the diffusion time (Δ), and 3He ADC has been shown to be anisotropic for Δ ranging from a few milliseconds down to a few hundred microseconds. In this study, the anisotropic nature of 129Xe diffusion and its dependence on Δ were investigated both numerically, in a budded cylinder model, and in vivo, in an elastase‐instilled rat model of emphysema. Whole lung longitudinal ADC (DL) and transverse ADC (DT) were measured for Δ = 6, 50, and 100 ms at 73.5 mT, and correlated with measurements of the mean linear intercept (Lm) obtained from lung histology. A significant increase (P = 0.0021) in DT was measured for Δ = 6 ms between the sham (0.0021 ± 0.0005 cm2/s) and elastase‐instilled (0.005 ± 0.001 cm2/s) cohorts, and a strong correlation was measured between DT (Δ = 6 ms) and Lm, with a Pearson's correlation coefficient of 0.90. This study confirms that 129Xe DT increases correlate with alveolar space enlargement due to elastase instillation in rats. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Prävention und Therapie von entzündlichen Magen‐/Darm‐Erkrankungen
Authors: Stein Jürgen , Dignaß Axel 
Published: March 2012

AbstractProbiotika können bei verschiedenen Infektionen und chronischen Entzündungen des Magen‐Darm‐Traktes erfolgreich eingesetzt werden. Der folgende Artikel fasst die aktuelle Studienlage zusammen.
Synthesis and optimization of molecularly imprinted polymers for quercetin
Authors: Yu Hui , Chen Zhenbin , Fu Yu , Kang Lei , Wang Meng , Du Xueyan 
Published: March 2012

AbstractMolecularly imprinted polymers (MIPs) were synthesized through solution polymerization using quercetin as the template molecule, N‐vinylpyrrolidone and acrylic acid as functional monomers, N,N′‐methylenebiacrylamide as crosslinker and the redox system L‐ascorbic acid and hydrogen peroxide as initiator in the porogen of ethanol and water. During the optimization process an interference compound, genistein (5,7,4′‐trihydroxy isoflavone), which possesses the same skeleton and functional groups as quercetin, was adopted to optimize the preparation conditions, and the separation degree of the MIP to quercetin and genistein was chosen to optimize each factor. The synthesized MIP under optimal conditions showed a specific recognition of quercetin from a mixture of quercetin and genistein. Thereafter, the structure of the MIP was comparatively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and Brunauer–Emmett–Teller analysis using non‐imprinted molecular polymers as control. In addition, the kinetics of the adsorption process were also studied, and Scatchard analysis revealed that heterogeneous binding sites were formed in the polymers. Copyright © 2012 Society of Chemical Industry
Täglich genutzt und kaum bekannt
Authors: Ehrmann Andrea , Blachowicz Tomasz 
Published: March 2012

AbstractDer Exchange Bias gehört zu den physikalischen Effekten, die trotz ihrer technologischen Relevanz kaum bekannt sind. Seine wichtigste Anwendung ist der Einsatz in Schreibleseköpfen von Festplatten. Durch ihn sind sie so empfindlich geworden, dass sie extrem kleine magnetische Domänen als Bits lesen können. Das eröffnete den Weg zu Festplatten mit Kapazitäten von vielen Gigabytes. Der Effekt entsteht durch die Kombination von ferromagnetischen mit antiferromagnetischen Materialien. Obwohl bereits 1956 entdeckt, ist er theoretisch noch nicht völlig verstanden. Auch heute bietet er der Grundlagenforschung ein reiches Feld neuer Entdeckungen. Diese könnten wiederum Eingang in neue Technologien finden.
Lorentz‐Pendel in der Glühbirne
Authors: Vollmer Michael , Möllmann Klaus‐Peter 
Published: March 2012

AbstractDie Lorentz‐Kraft auf bewegte Ladungen im Magnetfeld lässt sich auf unterschiedliche Weise demonstrieren. Ein beeindruckendes Beispiel ist die wechselstromdurchflossene Wendel einer Glühlampe, die in einem zeitlich konstanten Magnetfeld schwingt. Mit einer Hochgeschwindigkeitskamera kann man diese schnelle Bewegung zeitaufgelöst darstellen.