Electron microscopic visualization of tRNA genes with ferritin-avidin: biotin labels

A method is described for indirect electron microscopic visualization and mapping of tRNA and other short transcripts hybridized to DNA. This method depends upon the attachment of the electron-dense protein ferritin to the RNA, the binding being mediated by the remarkably strong association of the egg white protein avidin with biotin. Biotin is covalently attached to the 3' end of tRNA using an NH2 (CH2) 5NH2 bridge. The tRNA-biotin adduct is hybridized to complementcrry DNA sequences present in a single stranded nonhomology loop of a DNA:DNA heteroduplex. Avidin, covalently crosslinked to ferritin is mixed with the heteroduplex and becomes bound to the hybridized tRNA-biotin. Observation of the DNA:RNA-biotin:avidin-ferritin complex by electron microsdopy specifically and accurately reveals the position of the tRNA gene, with a frequency of labeling of approximately 50%

First US Performance Measurements of Next Generation 3D USCT 2.5 Transducers

The KIT’s 3D Ultrasound Computer Tomography (USCT) II system has a multistatic setup of 2041 ultrasound transducers with approx. 1.5 MHz 6dB bandwidth and 36◦ 3 dB opening angle for 2.5 MHz. To increase the region of interest for a next USCT generation, the opening angle should be increased to approx. 60◦ and the bandwidth doubled. To increase the opening angle the size of the transducer elements was decreased to approximately half the size. A circular aperture was chosen for homogenicity of the radiation pattern in 3D. The transducer design utilizes piezo-fibres by the established Fraunhofer IMT piezo-fibre composite technology. The fibres were fabricated from PZT powder using the polysulfone spinning process. 17 fibres were positioned with a mechanical mask and filled with a matrix of epoxy. From this rod piezo composite discs were sawed and polarized. Electrodes were generated by silver-filled epoxy adhesive on the top and bottom side. Materials for acoustic backing is a Tungsten-Polyurethane composite and for acoustic matching ia aluminium oxide composite material (TMM4). Ultrasound characteristics were evaluated quantitatively with a Onda HNC-400 hydrophone in a 3-axis water tank for a randomly selected sample transducer (see Fig. a.)). Characteristics evaluated were the pressure field as function over frequency and angle in the far-field (see Fig. b.)), following the use-case. For excitation a linear encoded chirp was used, for SNR improvements averaging of measurements (64 to 256 times) was conducted. The analysis compensated for the hydrophon’s frequency and angular damping characteristics. The presented results show that the desired characteristics were mostly achieved: the 6 dB bandwidth could be vastly improved by roughly 200% (see Fig. d.)). The 6 dB pressure opening angle was approx. 50◦ (see Fig. c.)), not completly fullfilling the simulated expectations, an improvement by 31% was achieved. The results are promising for the next 3D USCT III generation

Validating the Demand Control Support Questionnaire among white-collar employees in Switzerland and the United States

Background: The Demand Control Support Questionnaire (DCSQ) is an established self-reported tool to measure a stressful work environment. Validated German and English versions are however currently missing. The aim of this study was therefore to evaluate the psychometric properties of German and English versions of the DCSQ among white-collar employees in Switzerland and the US. Methods: This cross-sectional study was carried out on 499 employees in Switzerland and 411 in the US, respectively. The 17-item DCSQ with three scales assessed psychosocial stress at work (psychological demands, decision latitude, and social support at work). Depressive symptoms were measured by the 2-item Patient Health Questionnaire. Cronbach’s α and item-total correlations tested the scale reliability (internal consistency). Construct validity of the questionnaire was examined using exploratory factor analysis (EFA). Logistic regressions estimated associations of each scale and job strain with depressive symptoms (criterion validity). Results: In both samples, all DCSQ scales presented satisfactory internal consistency (Cronbach’s α ≥ 0.72; item-total correlations ≥ 0.33), and EFA showed the 17 items loading on three factors, which is in line with the theoretically assumed structure of the DCSQ construct. Moreover, all three scales as well as high job strain were significantly associated with depressive symptoms. The associations were stronger in the US sample. Conclusions: The German and the English versions of the DCSQ seem to be reliable and valid instruments to measure psychosocial stress based on the job demand-control-support model in the workplace of white-collar employees in Switzerland and the US

Reservoir fracture characterizations from seismic scattered waves

The measurements of fracture parameters, such as fracture orientation, fracture density and fracture compliance, in a reservoir is very important for field development and exploration. Traditional seismic methods for fracture characterization include shear wave birefringence (Gaiser and Dok, 2001; Dok et al., 2001; Angerer et al., 2002; Vetri et al., 2003) and amplitude variations with offset and azimuth (AVOA) (Ruger, 1998; Shen et al., 2002; Hall et al., 2003; Liu et al., 2010; Lynn et al., 2010). These methods are based on the equivalent medium theory with the assumption that fracture dimension and spacing are small relative to the seismic wave length, so a fracture zone behaves like an equivalent anisotropic medium. But fractures on the order of seismic wave length are also very important for enhanced oil recovery, and they are one of the important subsurface scattering sources that generate scattered seismic waves. Willis et al. (2006) developed the Scattering Index method to extract the fracture scattering characteristics by calculating the transfer funtion of a fracture zone. Fang et al. (2011) proposed a modification of the SI method (the Fracture Transfer Function (FTF) method) that leads to a more robust fracture characterization. In this paper, we use both laboratory data and field data to explore the capability of the FTF method.Eni-MIT Energy Initiative Founding Member Progra

Исследование влияния природы растворителя, используемого при получении электродной мембраны, на работу Ni-селективного электрода при определении ионов никеля (LL) в водных средах

Исследовано влияние природы растворителей (бензиловый спирт и хлорфенол), используемых для изготовления полимерной электродной мембраны твердофазного никельселективного электрода на основе никельгексационоферратов ({Ni2[Fe(CN)6]}), иммобилизованных в полиэтилентерефталатную (ПЭТФ) матрицу для определения ионов никеля в водных средах. Установлено, что мембраны, полученные на основе бензилового спирта имеют более высокие электродные показатели по сходимости и воспроизводимости потенциалов, стабильности работы, низком дрейфе и времени отклика электрода по сравнению с мембранами на основе хлорфенола и могут быть рекомендованы к использованию в никель селективных электродах.The influence of the nature of the solvents (benzyl alcohol and chlorophenol) used to fabricate a polymer electrode membrane of a solid-phase nickel selective electrode based on nickelhexacetanoferrates ({Ni2 [Fe (CN) 6]}) immobilized in a polyethylene terephthalate (PET) matrix for the determination of nickel ions in aqueous media . It has been established that membranes obtained on the basis of benzyl alcohol have higher electrode indices for the convergence and reproducibility of potentials, stability of operation, low drift and electrode response time compared to chlorophenol-based membranes, and can be recommended for use in nickel selective electrodes

Implementation of REACH in the New Member States - Part two: Business Case Studies in Selected New Member States

This report informs about potential impacts of the European regulation concerning the registration, evaluation, authorisation and restriction of chemicals REACH (Regulation (EC) No 1907/2006) in the New Member States . It consists of two parts: 1) "Implementation of REACH in the New Member States – Part one: overview of the chemical and specialty chemical sector in the New Member States", and 2) "Implementation of REACH in the New Member States – Part two: Business case studies in selected New Member States". The first report gives a general overview of the chemical sector in all New Member States and provides key macroeconomic data for the description of the chemical sector as a whole in each of the countries. This includes the sectors development, major developments including trade with EU-15 and non-EU countries, and a description of sub-sectors according to NACE categories. Furthermore, the first report describes the impact on the chemical industry through the implementation of the Chemicals Acquis and the Accession to the EU, and derives the implications for the adoption of REACH in the New Member States. Finally, the report outlines REACH Impact studies which are available in the New Member States . The second report analyses the ability of specialty chemicals companies in selected countries to implement REACH . This ability is examined on the basis of techno-economic case studies. From the economic aspect, the impact on costs and prices is analysed, substance withdrawal, administrative impact, capacity needs and the competitiveness on European and international markets. From the technological point of view the impact of REACH on innovation, replacement of substances and process adaptation is looked at. The strategic analysis looked at alternatives to cope with REACH (such as the import of components, relocation to non-EU countries etc.), the potential of companies to adapt to the changing legal framework (including the implementation of the environmental acquis) and the relative importance of REACH as one amongst different drivers for change.JRC.J.2-Competitiveness and Sustainabilit

Transcriptome Analysis in Peripheral Blood of Humans Exposed to Environmental Carcinogens: A Promising New Biomarker in Environmental Health Studies

BACKGROUND: Human carcinogenesis is known to be initiated and/or promoted by exposure to chemicals that occur in the environment. Molecular cancer epidemiology is used to identify human environmental cancer risks by applying a range of effect biomarkers, which tend to be nonspecific and do not generate insights into underlying modes of action. Toxicogenomic technologies may improve on this by providing the opportunity to identify, molecular biomarkers consisting of altered gene expression profiles. OBJECTIVES: The aim of the present study, was to monitor the expression of selected genes in a random sample of adults in Flanders selected from specific regions with (presumably,) different environmental burdens. Furthermore, associations of gene expression with blood and urinary, measures of biomarkers of exposure, early, phenotypic effects, and tumor markers were investigated. RESULTS: Individual gene expression of cytochrome p450 1B1, activating transcription factor 4, mitogen-activated protein kinase K superoxide dismutase 2 (Mn), chemokine (C-X-C motif) ligand 1 (melanoma growth stimulating activity, alpha), diacylglycerol 0 acyltransferase homolog 2 (mouse), tigger transposable element derived 3, and PTEN-induced putative kinasel were measured by means of quantitative polymerase chain reaction in peripheral blood cells of 398 individuals. After correction for the confounding effect of tobacco smoking, inhabitants of the Olen region showed the highest differences in gene expression levels compared with inhabitants from the Gent and fruit cultivation regions. Importantly, we observed multiple significant correlations of particular gene expressions with blood and urinary, measures of various environmental carcinogens. CONCLUSIONS: Considering the observed significant differences between gene expression levels in inhabitants of various regions in Flanders and the associations of gene expression with blood or urinary measures of environmental carcinogens, we conclude that gene expression profiling appears promising as a tool for biological monitoring in relation to environmental exposures in humans

Hydrogen crystals reduce dissipation in superconducting resonators

We show that the internal quality factors of high impedance superconducting resonators made of granular aluminum can be improved by coating them with micrometric films of solid para-hydrogen molecular crystals. We attribute the average measured $\approx 8\%$ reduction in dissipation to absorption of stray terahertz radiation at the crystal-resonator interface and the subsequent dissipation of its energy in the form of phonons below the pair-breaking gap. Our results prove that, contrary to expectations, replacing the vacuum dielectric atop a superconducting resonator can be beneficial, thanks to the added protection against Cooper pair-braking terahertz radiation. Moreover, at the level of internal quality factors in the $10^5$ range, the hydrogen crystal does not introduce additional losses, which is promising for embedding impurities to couple to superconducting thin-film devices in hybrid quantum architectures