Ionic Transport and Water Vapor Uptake of Ammonium Exchanged Perfluorosulfonic Acid Membranes

Nafion membranes series N117 doped with ammonium, at different cation fractions (H+/NH4+), were investigated for ionic transport and water vapor uptake, for several water activities and temperatures. Ammonium cations change both properties of the polymer in a similar manner. Membrane ionic conductivity and water vapor uptake (lambda) decrease as the ammonium concentration increases in the polymer. Ionic transport activation energies are calculated and the transport mechanism of ammonium ions in Nafion is discussed. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.040203jes] All rights reserved.

Risposte di resistenza a batteri fitopatogeni di importanti specie coltivate indotte da molecole segnale di diversa natura

A modern management of crop protection should be based on integrated control programmes, including the use of environmentally safe products. Antagonistic/beneficial bacteria and resistance inducers may have a great potential in the prophylaxis of diseases caused by common and quarantine pathogens. This work was carried out to confirm the ability of the known strain IPV-BO G19 (Pseudomonas fluorescens) against fire blight (Erwinia amylovora), as well as to evaluate their efficacy against southern bacterial wilt of tomato (Ralstonia solanacearum) and grapevine crown gall (Agrobacterium vitis). A virulent strain of R. solanacearum race 3 was inhibited by the antagonist on plate. When the pathogen was inoculated 48 h after their application to the root apparatus of tomato plants grown in a climatic chamber, bacterial wilt progression rate was clearly reduced. Moreover the defence response evoked by IPV-BO G19 was studied in tomato plants by monitoring the transcription of genes codifying for three PRs as PR-1a, PR-4, PR-5 and for an intracellular chitinase using multiplex RT-PCR and Real Time RT-PCR. In two field trials during 2005 and 2006, the strain IPV-BO G19 was compared with biofungicides and some abiotic elicitors to protect actively growing shoots of pear scions against fire blight. In both trials, IPV-BO G19 plus Na-alginate gave a high level of protection, three weeks after wound inoculation with E. amylovora. In pear leaf tissues treated with the antagonistic strain IPV-BO G19, catalase, superoxyde dismutase and peroxidise activity was evaluated as markers of induced resistance. The IPV-BO G19 strain was compared with other bioagents and resistance inducers to prevent grapevine crown gall under glasshouse and vineyard conditions.

Selektiv deblockierbare 2,6-Diamino-2,6-didesoxy-D-glucose-Scaffolds für die kombinatorische Synthese potentieller RNA-Liganden

Aminoglydosid-Antibiotika wie Neomycin B oder Cyclopeptid-Antibiotike wie Viaomycin sind dafür bekannt, daß sie selektiv an RNA binden können. Diese Interaktionen beruhen sowohl auf elektrostatischen Wechselwirkungen als auch auf H-Brücken-Bindungen. Des weiteren ist die definierte räumliche Anordnung von Donor- und Akzeptor-Resten in den Strukturen der RNA-Liganden wichtig für die Affinität. Eine Möglichkeit natürliche RNA-Liganden zu imitieren ist der Einsatz polyfunktioneller Template wie zum Beispiel das 2,6-Diamino-2,6-didesoxy-D-glucose-Scaffold. Mit Hilfe dieser Scaffolds können dann verschiedene positv geladene Reste und Donatoren sowie Akzeptoren für H-Brücken-Bindungen oder auch Interkalatoren räumlich definiert präsentiert werden. Für die unabhängige Funktionalisierung einer jeden Position ist ein Satz orthogonal stabiler Schutzgruppen nötig, wobei eine Hydroxylguppe durch einen Anker ersetzt wird, der eine Anbindung des Scaffolds an einen polymeren Träger ermöglicht. Das neu entwickelte 2,6-Diamino-2,6-didesoxy-D-glucose-Scaffold ist das erste Monosaccharid-Templat, das in allen fünf Positionen mit orthogonal stabilen Schutzgruppen blockiert ist. Alle Positionen könne in beliebiger Reihenfolge selektiv deblockiert und anschließend derivatisiert werden. Das Scaffold kann mit Aminosäuren, Guanidinen oder Interkalatoren umgesetzt werden, um so natürlich vorkommende RNA-bindende Aminoglycoside oder Peptide zu imitieren. Aufbauend auf diesem Monosaccharid-Templat wurde eine Bibliothek von über 100 potentiellen RNA-Liganden synthetisiert, die im Rahmen des Sonderforschungsbereichs 579 (RNA-Liganden-Wechselwirkungen) in Zellassays auf ihre Fähigkeit zur Hemmung der Tat/TAR-Wechselwirkung untersucht wurden, wobei bis jetzt 9 Verbindungen mit einer hemmenden Wirkung im micromolaren Bereich gefunden wurden.

The incidence and health economic burden of ischemic amputation in Minnesota, 2005-2008

Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery disease (PAD), is associated with high rates of myocardial infarction, stroke, and amputation, and has a high health economic cost. The objective of this study was to estimate the incidence of lower limb amputation, the most serious consequence of CLI, and to create a surveillance methodology for the incidence of ischemic amputation in Minnesota.

Dexmedetomidine vs midazolam or propofol for sedation during prolonged mechanical ventilation: two randomized controlled trials

Long-term sedation with midazolam or propofol in intensive care units (ICUs) has serious adverse effects. Dexmedetomidine, an α(2)-agonist available for ICU sedation, may reduce the duration of mechanical ventilation and enhance patient comfort.

Effects Of Perceived Financial Accessibility Of Colleges And Universities On Studentsâ¿ Assesment Of Institutional Desirability

This study focused on the effects of socioeconomic exclusivity indicators on college students¿ attitudes toward a hypothetical private liberal arts university. Students enrolled in two undergraduate courses in Education at an elite private liberal arts university in the northeast were randomly presented with one of three versions of an admissions brochure describing a fictitious university. The three versions of the brochure varied in their portrayals of the institution¿s financial exclusivity, ranging from high exclusivity to low exclusivity. Each student was asked to review the brochure and respond to a questionnaire, containing items pertaining to the overall desirability of the institution, as well as its student culture, academic program, campus traditions, and alumni network. Based on Thorstein Veblen¿s theory of the leisure class and Pierre Bourdieu¿s theory of social reproduction, it was hypothesized that students would judge the institution most favorably in all areas under the high exclusivity condition and least favorably under the low exclusivity condition. It was further hypothesized that differences in students¿ ratings of institutional desirability would be mediated by their own financial aid statuses. Results of a two-way multivariate analysis of variance (MANOVA) revealed significant (p < .05) interactive effects of institutional exclusivity and student aid status on the perceived desirability of the academic program and campus traditions of the institution. While recipients of need-based financial aid tended to rate more socioeconomically exclusive institutions more favorably on these two variables, those who were not receiving need-based financial aid tended to rate such institutions less favorably. Implications of the findings for student affairs practice are discussed and recommendations for further research are presented.