Power and limitations of electrophoretic separations in proteomics strategies

Proteomics can be defined as the large‐scale analysis of proteins. Due to the complexity of biological systems, it is required to concatenate various separation techniques prior to mass spectrometry. These techniques, dealing with proteins or peptides, can rely on chromatography or electrophoresis. In this review, the electrophoretic techniques are under scrutiny. Their principles are recalled, and their applications for peptide and protein separations are presented and critically discussed. In addition, the features that are specific to gel electrophoresis and that interplay with mass spectrometry (i.e., protein detection after electrophoresis, and the process leading from a gel piece to a solution of peptides) are also discussed. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 28:816–843, 2009     

Two-Dimensional Ordering of Coumarin at the Indium Amalgam–Electrolyte Interface

The two-dimensional condensation of coumarin was investigated at the indium amalgam-aqueous solution interface by capacitance-potential and charge-time measurements. Two distinct adsorption states were found for saturated coumarin solutions in 0.5 M NaF at 10 °C. Similar to the adsorption behavior on mercury, coumarin molecules can form a monolayer presenting the characteristics of a two-dimensional condensed layer. An increase of the indium content of the amalgam leads to an extension of the stability range of the condensed monolayer at most negative potentials. The shift of the transition potential parallels the variation of the pzc of the amalgams. The kinetics of condensation of coumarin were investigated by the potential step technique at a 50% In-Hg electrode. Mononuclear transients leading to the condensed film are observed in a wide range of the overvoltage. A comparison of the data obtained at the amalgam and mercury electrodes shows that the growth rate is independent of the nature of the electrode and that the detection of a single event takes place at lower supersaturations at the amalgam electrode.     

L'influence de l'approche psychothérapeutique et de l'expérience professionnelle sur les attentes des thérapeutes.

Evaluated the influence of theoretical orientation and professional experience on therapists' expectancies. In an analog study, 199 registered psychologists were asked to read a case history of a hypothetical client and to answer an 8-point Likert type expectancies inventory. From a 61-item inventory, 3 types of therapist expectancies were examined: diagnostic (anticipations of client need), prognostic (assessments of probable client outcomes), and process expectancies (anticipated use of directiveness and interpretations). A MANOVA with unweighted means was performed. Use of a Wilks lambda criterion produced no significant interaction effects. The main effect for Professional Experience was not significant. However, a significant main effect was found for Therapist Theoretical Orientation. Discriminant function analysis clarified the meaning of these results. Group centroids indicated that behaviorists expect to be more active and anticipate fewer client needs than psychoanalysts and phenomenologists. Psychoanalysts expect to be less active and anticipate more client needs, while phenomenologists expect to be moderately active and anticipate moderate client needs. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiscale analysis of the laser-induced damage threshold in optical coatings

We have investigated the influence of laser beam size on laser-induced damage threshold (LIDT) in the case of single- and multiple-shot irradiation. The study was performed on hafnia thin films deposited with various technologies (evaporation, sputtering, with or without ion assistance). LIDT measurements were carried out at 1064 nm and 12 ns with a spot size ranging from a few tens to a few hundreds of micrometers, in 1-on-1 and R-on-1 modes. These measurements were compared with simulations obtained with the statistical theory of laser-induced damage caused by initiating inclusions. We show how to obtain information on the initiating defect properties and the related physical damage mechanisms with a multiscale study. Under certain conditions, it is possible with this method to discriminate different defects, estimate their densities, and follow the evolution of the defects under multiple irradiation. The different metrology implications of our approach, particularly for obtaining a functional LIDT of optical components are discussed.     

Tiring job and work related injury road crashes in the GAZEL cohort

The objective was to describe at-work and commuting crashes occurring in a cohort of French employees and to investigate occupational risk factors. The subjects were employees of the French national electricity and gas companies, Électricité de France and Gaz de France (EDF–GDF), who volunteered to join a research cohort (the GAZEL cohort which included 20,625 participants in 1989). Only crashes with injuries were considered. Crashes for the periods 1989–2001 were recorded together with the type of journey (commuting, work, private), the type of road-user, self-estimated responsibility, and injuries sustained by the subject. Annual incidences for gender/age groups and socio-occupational groups were computed for each of the two types of work related crashes. Occupational risk factor analyses were conducted using a Cox proportional hazards regression model with time-dependent covariates adjusting for the main confounders. A total of 146,285 person years at work were observed. Two indicators of self-reported work fatigue were associated with the occurrence of at-work crashes: “nervously tiring work” for males (RR = 1.6, 95% CI [1.1; 2.3]), sustained standing for females (RR = 3.0, 95% CI [1.0; 8.4]), adjusting for health status, location of residence, type of family, transport mode and mileage. As regards crashes while commuting, a self-reported uncomfortable position at work was a risk factor among women (RR = 1.9, 95% CI [1.1; 3.3]). On the other hand, these occupational factors were not linked to road crashes in private trips. Work related road crashes seem then to be a matter for a specific prevention. Preventing employees from becoming exhausted should be considered as the first way to initiate such a prevention.     

Polarization-dependent vacuum-ultraviolet reflectometry using elliptically polarized synchrotron radiation

In the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the Berlin electron-storage ring BESSY II, a procedure has been developed to investigate the dependence of vacuum-ultraviolet reflection on polarization. It is based on characterizing the elliptically polarized synchrotron radiation at PTB's normal-incidence monochromator beamline for reflectometry by means of polarization-sensitive photodetectors. For this purpose, the polarization dependency in the detector responsivity was determined at a small, low, solid angle of acceptance for the synchrotron radiation, i.e., within the orbital plane of the storage ring where the degree of linear polarization is known to be almost 100%. Our method allows the polarization dependence of reflection samples to be measured with relative standard uncertainties ranging from 2.4% to 11% in the spectral range between 60 and 160 nm. The method has been applied to the optimization of polarizing mirrors at the Lyman-alpha wavelength of 121.6 nm.     

Biomimetic models of the actin cytoskeleton

The cytoskeleton is a complex polymer network that plays an essential role in the functionality of eukaryotic cells. It endows cells with mechanical stability, adaptability, and motility. To identify and understand the mechanisms underlying this large variety of capabilities and to possibly transfer them to engineered networks makes it necessary to have in vitro and in silico model systems of the cytoskeleton. These models must be realistic representatives of the cellular network and at the same time be controllable and reproducible. Here, an approach to design complementary experimental and numerical model systems of the actin cytoskeleton is presented and some of their properties discussed.     

Design and Guideline Rules for the Performance Improvement of Vertically Integrated Nanogenerator

Piezoelectric nanowires have attracted much scientific interest in the last few years because of their enhanced piezoelectric coefficients at nanometer scale, with promises of efficient mechanical energy harvesters for autonomous integrated systems. This paper presents the design and, for the first time, guideline rules, based on simple analytical expressions, to improve the performance of a mechanical energy harvester integrating vertical ZnO piezoelectric nanowires. Additional simulations were carried out to account more realistically for device geometry. The authors discuss the prospects of such an approach, based on design and material improvement.     

Nonlinear parity space applied to an electric autonomous vehicle

The autonomous navigation of an electric vehicle requires the implementation of a number of sensors and actuators intended to inform it about his environment or his position and velocity and deliver necessary inputs. That＇s why it is important to detect and locate sensor and actuator faults as soon as possible to enable the operator to run the vehicle in degraded mode or use the fault tolerant control system if it exists. The main purpose of this paper deals with sensors or actuators faults diagnosis of autonomous vehicle. A diagnosis method using a nonlinear model of the vehicle is developed. Nonlinear state space model of the autonomous electric vehicle is used with the method of nonlinear analytical redundancy to detect and to isolate faults occurred on sensors or actuators. Computer simulations are carried out to verify the effectiveness of the method.