Active site structure and redox processes of cytochrome c oxidase immobilised in a novel biomimetic lipid membrane on an electrode

Membrane-bound cytochrome c oxidase was attached to an electrode via a His-tag linker and studied by surface enhanced resonance Raman spectroscopy, demonstrating intact redox site structures and electron transfer between the electrode and the immobilized enzyme.     

First Measurement of the Gerasimov-Drell-Hearn Sum Rule for 1H from 0.7 to 1.8 GeV at ELSA

To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the first time experimentally, we measured the helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally polarized nucleons in the photon energy range 0.68-1.82 GeV with the tagged photon facility at ELSA. The experiment was carried out with a 4pi detection system, a circularly polarized tagged photon beam, and a frozen spin polarized proton target. The contribution to the GDH sum rule in this photon energy range is [49.9+/-2.4(stat)+/-2.2(syst)] microb.     

Synthesis of a series of monomeric styrene sulfobetaine precursors

Procedures for the synthesis of five sulfobetaine monomers as styrene derivatives are given. The five molecules form a homologous row differing in the distance between the inner quaternary amine and the outer sulfonic acid from one methylene group to five methylene groups. Syntheses are achieved by a sequence of nucleophilic substitutions starting from commercially available precursors.     

Viscoelastic phase diagram of fluorinated and grafted polymer films and proton‐exchange membranes for fuel cell applications

The influence of temperature and moisture activity on the viscoelastic behavior of fluorinated membranes for fuel cell applications was investigated. Uncrosslinked and crosslinked ethylene tetrafluoroethylene (ETFE)‐based proton‐conducting membranes were prepared by radiation grafting and subsequent sulfonation and their behavior was compared with ETFE base film and commercial Nafion^® NR212 membrane. Uniaxial tensile tests and stress relaxation tests at controlled temperature and relative humidity (RH) were carried out at 30 and 50 °C for 10% < RH < 90%. Grafted films were stiffer and exhibited stronger strain hardening when compared with ETFE. Similarly, both uncrosslinked and crosslinked membranes were stiffer and stronger than Nafion^®. Yield stress was found to decrease and moisture sensitivity to increase on sulfonation. The viscoelastic relaxation of the grafted films was found to obey a power‐law behavior with exponent equal to ?0.04 ± 0.01, a factor of almost 2 lower than ETFE, weakly influenced by moisture and temperature. Moreover, the grafted films presented a higher hygrothermal stability when compared with their membranes counterparts. In the case of membranes, a power‐law behavior at RH < 60% was also observed. However, a markedly different behavior was evident at RH > 60%, with an almost single relaxation time exponential. An exponential decrease of relaxation time with RH from 60 s to 10 s was obtained at RH ≥ 70% and 30 °C. The general behavior of grafted films observed at 30 °C was also obtained at 50 °C. However, an anomalous result was noticed for the membranes, with a higher modulus at 50 °C when compared with 30 °C. This behavior was explained by solvation of the sulfonic acid groups by water absorption creating hydrogen bonding within the clusters. A viscoelastic phase diagram was elaborated to map critical conditions (temperature and RH) for transitions in time‐dependent behavior, from power‐law scaling to exponential scaling. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1139–1148     

Investigation of X-ray Emission from Plasmas Created by NIXE 6-nsec Nd: Glass Laser System

This paper reports details on the design of the Nd: glass laser facility NIXE at the Central Institute of Optics and Spectroscopy, including the target chamber and the x-ray diagnostics, spatial and temporal behaviour of the 1.06 μm radiation generated are given. Plane, massive targets of aluminium and silicon have been irradiated with 6-nsec FWHM laser pulses. Investigations of laser produced Al- and Si-plasmas have been performed with spectral and spatial high resolution diagnostics, consisting of a 3 channel crystal-spectrometer, 2 crystal-microscopes, and 2 pinhole cameras and the results are presented. Line spectra have been interpreted within the hypothesis of a steady state coronal equilibrium. He-like lines of the Al-plasma indicate temperatures up to 400 eV and densities up to 2 · 10²⁰ cm^?3. Total x-ray photon flux in the He-like resonance line has been calculated giving 10¹³ phot/ster.     

Aluminium

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