Porous Alumina Based Capacitive MEMS RH Sensor

The aim of a joint research and development project at the BME and HWU is to produce a cheap, reliable, low-power and CMOS-MEMS process compatible capacitive type relative humidity (RH) sensor that can be incorporated into a state-of-the-art, wireless sensor network. In this paper we discuss the preparation of our new capacitive structure based on post-CMOS MEMS processes and the methods which were used to characterize the thin film porous alumina sensing layer. The average sensitivity is approx. 15 pF/RH% which is more than a magnitude higher than the values found in the literature. The sensor is equipped with integrated resistive heating, which can be used for maintenance to reduce drift, or for keeping the sensing layer at elevated temperature, as an alternative method for temperature-dependence cancellation.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Structure analysis of proteins, peptides and metal complexes by vibrational circular dichroism

There are two principal forms of vibrational optical activity (VOA), an IR form referred to as vibrational circular dichroism (VCD) and Raman form known as Raman optical activity (ROA). This paper reports examples of the application of VCD spectroscopy for the determination of the absolute configuration and conformation of chiral molecules, e. g. cyclic beta-lactams. VCD spectroscopy can be applied for the characterization of the conformation of proteins and peptides in solution. VCD based conformational analysis of cyclic peptides is discussed. Examples are the cyclic hexapeptide cyclo(Pro(2)-Gly-Pro(2)-Gly) and cyclic peptides comprising beta-homoamino acids (trans-2-aminocyclopentane or trans-2-aminocyclohexane carboxylic acid). Structure analysis by VCD of opiate peptides, glycopeptides, peptidomimetics and chiral transition metal complexes are also discussed

Histidine residue 252 of the Photosystem II D1 polypeptide is involved in a light-induced cross-linking of the polypeptide with the α subunit of cytochrome b-559: study of a site-directed mutant of Synechocystis PCC 6803

AbstractProperties of the Photosystem II (PSII) complex were examined in the wild-type (control) strain of the cyanobacterium Synechocystis PCC 6803 and its site-directed mutant D1-His252Leu in which the histidine residue 252 of the D1 polypeptide was replaced by leucine. This mutation caused a severe blockage of electron transfer between the PSII electron acceptors QA and QB and largely inhibited PSII oxygen evolving activity. Strong illumination induced formation of a D1–cytochrome b-559 adduct in isolated, detergent-solubilized thylakoid membranes from the control but not the mutant strain. The light-induced generation of the adduct was suppressed after prior modification of thylakoid proteins either with the histidine modifier platinum-terpyridine-chloride or with primary amino group modifiers. Anaerobic conditions and the presence of radical scavengers also inhibited the appearance of the adduct. The data suggest that the D1–cytochrome adduct is the product of a reaction between the oxidized residue His252 of the D1 polypeptide and the N-terminal amino group of the cytochrome α subunit. As the rate of the D1 degradation in the control and mutant strains is similar, formation of the adduct does not seem to represent a required intermediary step in the D1 degradation pathway

The role of carbon species in heterogeneous catalytic processes: an in situ soft x-ray photoelectron spectroscopy study

High pressure X-ray photoelectron spectroscopy (XPS) is used to characterize heterogeneous catalytic processes. The success of the new technique based on the possibility to correlate the catalytic activity and the electronic structure of an active surface. The dynamic character of a catalyst surface can be demonstrated impressively by this technique. In this contribution the basics of high pressure XPS will be discussed. Three examples of heterogeneous catalytic reactions are presented in this contribution. The selective hydrogenation of 1-pentyne over Pd based catalysts and the dehydrogenation of n-butane and the oxidation of ethylene over V based catalysts. It is shown, that the formation of subsurface carbons plays an important role in all the examples. The incorporated carbon changes the electronic structure of the surface and so controls the selectivity of the reaction. A change of the educts in the reaction atmosphere induces modifications of the electronic surface structure of the operation catalysts

Control sideband generation for dual-recycled laser interferometric gravitational wave detectors

We present a discussion of the problems associated with generation of multiple control sidebands for length sensing and control of dual-recycled, cavity-enhanced Michelson interferometers and the motivation behind more complicated sideband generation methods. We focus on the Mach–Zehnder interferometer as a topological solution to the problem and present results from tests carried out at the Caltech 40 m prototype gravitational wave detector. The consequences for sensing and control for advanced interferometry are discussed, as are the implications for future interferometers such as Advanced LIGO

How stigma impacts on people with psychosis: The mediating effect of self-esteem and hopelessness on subjective recovery and psychotic experiences

This study aimed to examine how stigma impacts on symptomatic and subjective recovery from psychosis, both concurrently and longitudinally. We also aimed to investigate whether self-esteem and hopelessness mediated the observed associations between stigma and outcomes. 80 service-users with psychosis completed symptom (Positive and Negative Syndrome Scale) and subjective recovery measures (Process of Recovery Questionnaire) at baseline and 6-months later, and also completed the King Stigma Scale, the Self-Esteem Rating Scale and the Beck Hopelessness Scale at baseline. In cross sectional regression and multiple mediation analyses of the baseline data, we found that stigma predicted both symptomatic and subjective recovery, and the effects of stigma on these outcomes were mediated by hopelessness and self-esteem. When the follow-up data were examined, stigma at baseline continued to predict recovery judgements and symptoms. However, self-esteem only mediated the effect of stigma on PANSS passive social withdrawal. Self-esteem and hopelessness should be considered in interventions to reduce the effects of stigma. Interventions that address the current and long-term effects of stigma may positively affect outcome for people being treated for psychosis