Influence of air diffusion on the OH radicals and atomic O distribution in an atmospheric Ar (bio)plasma jet

Treatment of samples with plasmas in biomedical applications often occurs in ambient air. Admixing air into the discharge region may severely affect the formation and destruction of the generated oxidative species. Little is known about the effects of air diffusion on the spatial distribution of OH radicals and O atoms in the afterglow of atmospheric-pressure plasma jets. In our work, these effects are investigated by performing and comparing measurements in ambient air with measurements in a controlled argon atmosphere without the admixture of air, for an argon plasma jet. The spatial distribution of OH is detected by means of laser-induced fluorescence diagnostics (LIF), whereas two-photon laser-induced fluorescence (TALIF) is used for the detection of atomic O. The spatially resolved OH LIF and O TALIF show that, due to the air admixture effects, the reactive species are only concentrated in the vicinity of the central streamline of the afterglow of the jet, with a characteristic discharge diameter of similar to 1.5 mm. It is shown that air diffusion has a key role in the recombination loss mechanisms of OH radicals and atomic O especially in the far afterglow region, starting up to similar to 4mm from the nozzle outlet at a low water/oxygen concentration. Furthermore, air diffusion enhances OH and O production in the core of the plasma. The higher density of active species in the discharge in ambient air is likely due to a higher electron density and a more effective electron impact dissociation of H2O and O-2 caused by the increasing electrical field, when the discharge is operated in ambient air

Ostdeutsche Agrarwirtschaft im Umbau:Die Herrschaft Birnbaum in südpreussisch-napoleonischer Zeit

Die ostelbische Gutsherrschaft war mit ihrem hierarchisch strukturierten sozialen Netzwerk eine weitgehend autarke Grundzelle der altpreussischen Gesellschaft und bot die wirtschaftliche Lebensgrundlage für die adelige Führungsschicht des Staates. Zu Beginn des 19. Jahrhunderts machte sie infolge der Bauernbefreiung und des Übergangs zu einer gewinn- und marktorientierten Produktionsweise einen tiefgreifenden Wandel durch. Mit der vorliegenden Studie werden Daten zur konkreten Lebens-, Wirtschafts- und Arbeitswelt sowie zu den Modalitäten der Finanzierung eines Gutes bereitgestellt. Damit wird dem sozialhistorischen Phänomen der ostelbischen Gutswirtschaft für einen gewissen Zeitabschnitt eine empirisch gesicherte Basis gegeben. Aufgrund einer glücklichen Quellenlage wird die Binnenstruktur einer Gutswirtschaft bis in alle Einzelheiten analysiert und die Veränderung des Verständnisses von Gutswirtschaft bei den Besitzern hin zu einem reinen Wirtschaftsunternehmen aufgezeigt. <br/

Increasing the reliability of fully automated surveillance for central line–associated bloodstream infections

OBJECTIVETo increase reliability of the algorithm used in our fully automated electronic surveillance system by adding rules to better identify bloodstream infections secondary to other hospital-acquired infections.METHODSIntensive care unit (ICU) patients with positive blood cultures were reviewed. Central line–associated bloodstream infection (CLABSI) determinations were based on 2 sources: routine surveillance by infection preventionists, and fully automated surveillance. Discrepancies between the 2 sources were evaluated to determine root causes. Secondary infection sites were identified in most discrepant cases. New rules to identify secondary sites were added to the algorithm and applied to this ICU population and a non-ICU population. Sensitivity, specificity, predictive values, and kappa were calculated for the new models.RESULTSOf 643 positive ICU blood cultures reviewed, 68 (10.6%) were identified as central line–associated bloodstream infections by fully automated electronic surveillance, whereas 38 (5.9%) were confirmed by routine surveillance. New rules were tested to identify organisms as central line–associated bloodstream infections if they did not meet one, or a combination of, the following: (I) matching organisms (by genus and species) cultured from any other site; (II) any organisms cultured from sterile site; (III) any organisms cultured from skin/wound; (IV) any organisms cultured from respiratory tract. The best-fit model included new rules I and II when applied to positive blood cultures in an ICU population. However, they didn’t improve performance of the algorithm when applied to positive blood cultures in a non-ICU population.CONCLUSIONElectronic surveillance system algorithms may need adjustment for specific populations.Infect. Control Hosp. Epidemiol. 2015;36(12):1396–1400</jats:sec

Coupling of Voltage Sensing to Channel Opening Reflects Intrasubunit Interactions in Kv Channels

Voltage-gated K+ channels play a central role in the modulation of excitability. In these channels, the voltage-dependent movement of the voltage sensor (primarily S4) is coupled to the (S6) gate that opens the permeation pathway. Because of the tetrameric structure, such coupling could occur within each subunit or between adjacent subunits. To discriminate between these possibilities, we analyzed various combinations of a S4 mutation (R401N) and a S6 mutation (P511G) in hKv1.5, incorporated into tandem constructs to constrain subunit stoichiometry. R401N shifted the voltage dependence of activation to negative potentials while P511G did the opposite. When both mutations were introduced in the same α-subunit of the tandem, the positive shift of P511G was compensated by the negative shift of R401N. With each mutation in a separate subunit of a tandem, this compensation did not occur. This suggests that for Kv channels, the coupling between voltage sensing and gating reflects primarily an intrasubunit interaction

Increased levels and pulsatility of Follicle-Stimulating Hormone in mothers of hereditary dizygotic twins

According to the endocrine model of hereditary dizygotic twinning, high FSH is responsible for multiple ovulation and pregnancy. Our study explored the underlying neuroendocrine causes

Kv Channel Gating Requires a Compatible S4-S5 Linker and Bottom Part of S6, Constrained by Non-interacting Residues

Voltage-dependent K+ channels transfer the voltage sensor movement into gate opening or closure through an electromechanical coupling. To test functionally whether an interaction between the S4-S5 linker (L45) and the cytoplasmic end of S6 (S6T) constitutes this coupling, the L45 in hKv1.5 was replaced by corresponding hKv2.1 sequence. This exchange was not tolerated but could be rescued by also swapping S6T. Exchanging both L45 and S6T transferred hKv2.1 kinetics to an hKv1.5 background while preserving the voltage dependence. A one-by-one residue substitution scan of L45 and S6T in hKv1.5 further shows that S6T needs to be α-helical and forms a “crevice” in which residues I422 and T426 of L45 reside. These residues transfer the mechanical energy onto the S6T crevice, whereas other residues in S6T and L45 that are not involved in the interaction maintain the correct structure of the coupling

Challenges in optics for Extremely Large Telescope instrumentation

We describe and summarize the optical challenges for future instrumentation for Extremely Large Telescopes (ELTs). Knowing the complex instrumental requirements is crucial for the successful design of 30-60m aperture telescopes. After all, the success of ELTs will heavily rely on its instrumentation and this, in turn, will depend on the ability to produce large and ultra-precise optical components like light-weight mirrors, aspheric lenses, segmented filters, and large gratings. New materials and manufacturing processes are currently under study, both at research institutes and in industry. In the present paper, we report on its progress with particular emphasize on volume-phase-holographic gratings, photochromic materials, sintered silicon-carbide mirrors, ion-beam figuring, ultra-precision surfaces, and free-form optics. All are promising technologies opening new degrees of freedom to optical designers. New optronic-mechanical systems will enable efficient use of the very large focal planes. We also provide exploratory descriptions of "old" and "new" optical technologies together with suggestions to instrument designers to overcome some of the challenges placed by ELT instrumentation.Comment: (Proc. OPTICON Key Technology Network Workshop, Rome 20-21 October 2005