152 research outputs found

    The Instrument Set for Generating Fast Adiabatic Passage

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    The design and construction of a high-performance, low-cost, and easy to assemble adiabatic extension set for homebuilt and commercial spectrometers is described. Described apparatus set was designed for the fast adiabatic passage generation and is based on direct digital synthesizer DDS. This solution gives generator high signal to noise ratio, phase stability even during frequency change which is only possible in expansive commercial high-end hardware. Critical synchronization and timing issues are considered and solutions are discussed. Different experimental conditions and techniques for the measurements are briefly discussed. The proposed system is very flexible and might be used for the measurement of low-frequency nuclear magnetic resonance

    UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces

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    Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications

    European Mixed Forests: definition and research perspectives

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    peer-reviewedAim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) briefly review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material and methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any developmental stage, sharing common resources (light, water, and/or soil nutrients). The presence of each of the component species is normally quantified as a proportion of the number of stems or of basal area, although volume, biomass or canopy cover as well as proportions by occupied stand area may be used for specific objectives. A variety of structures and patterns of mixtures can occur, and the interactions between the component species and their relative proportions may change over time. The research perspectives identified are (i) species interactions and responses to hazards, (ii) the concept of maximum density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields of research indicate that gradient studies, experimental design approaches, and model simulations are key topics providing new research opportunities.The networking in this study has been supported by COST Action FP1206 EuMIXFOR

    Teachers' conceptions on environment and GMO in twelve europen countries

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    We analyze the conceptions of 4248 teachers on Environment and GMO (Genetically Modified Organisms), in 12 European countries: Cyprus, Estonia, Finland, France, Germany, Hungary, Italy, Lithuania, Malta, Poland, Portugal, Romania. Most of the differences between teachers' conceptions are observed inside each country. Some of them (related to preservation or utilization of Environment) significantly differentiate the 12 countries. Biology teachers have more knowledge on GMO and more opinions pro- GMO than their colleagues. Female teachers are significantly more anti-GMO than their male colleagues. More a teacher studied at University, more he or she thinks that the resources of our planet are limited.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portuga

    Ceruloplasmin is a novel adipokine which is overexpressed in adipose tissue of obese subjects and in obesity-associated cancer cells

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    Obesity confers an increased risk of developing specific cancer forms. Although the mechanisms are unclear, increased fat cell secretion of specific proteins (adipokines) may promote/facilitate development of malignant tumors in obesity via cross-talk between adipose tissue(s) and the tissues prone to develop cancer among obese. We searched for novel adipokines that were overexpressed in adipose tissue of obese subjects as well as in tumor cells derived from cancers commonly associated with obesity. For this purpose expression data from human adipose tissue of obese and non-obese as well as from a large panel of human cancer cell lines and corresponding primary cells and tissues were explored. We found expression of ceruloplasmin to be the most enriched in obesity-associated cancer cells. This gene was also significantly up-regulated in adipose tissue of obese subjects. Ceruloplasmin is the body's main copper carrier and is involved in angiogenesis. We demonstrate that ceruloplasmin is a novel adipokine, which is produced and secreted at increased rates in obesity. In the obese state, adipose tissue contributed markedly (up to 22%) to the total circulating protein level. In summary, we have through bioinformatic screening identified ceruloplasmin as a novel adipokine with increased expression in adipose tissue of obese subjects as well as in cells from obesity-associated cancers. Whether there is a causal relationship between adipose overexpression of ceruloplasmin and cancer development in obesity cannot be answered by these cross-sectional comparisons

    Role of Receptor-Interacting Protein 140 in human fat cells

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    <p>Abstract</p> <p>Background</p> <p>Mice lacking <it>Receptor-interacting protein 140 (RIP140) </it>have reduced body fat which at least partly is mediated through increased lipid and glucose metabolism in adipose tissue. In humans, <it>RIP140 </it>is lower expressed in visceral white adipose tissue (WAT) of obese versus lean subjects. We investigated the role of <it>RIP140 </it>in human subcutaneous WAT, which is the major fat depot of the body.</p> <p>Methods</p> <p>Messenger RNA levels of <it>RIP140 </it>were measured in samples of subcutaneous WAT from women with a wide variation in BMI and in different human WAT preparations. <it>RIP140 </it>mRNA was knocked down with siRNA in <it>in vitro </it>differentiated adipocytes and the impact on glucose transport and mRNA levels of target genes determined.</p> <p>Results</p> <p><it>RIP140 </it>mRNA levels in subcutaneous WAT were decreased among obese compared to lean women and increased by weight-loss, but did not associate with mitochondrial DNA copy number. <it>RIP140 </it>expression increased during adipocyte differentiation <it>in vitro </it>and was higher in isolated adipocytes compared to corresponding pieces of WAT. Knock down of <it>RIP140 </it>increased basal glucose transport and mRNA levels of <it>glucose transporter 4 </it>and <it>uncoupling protein-1</it>.</p> <p>Conclusions</p> <p>Human <it>RIP140 </it>inhibits glucose uptake and the expression of genes promoting energy expenditure in the same fashion as the murine orthologue. Increased levels of human <it>RIP140 </it>in subcutaneous WAT of lean subjects may contribute to economize on energy stores. By contrast, the function and expression pattern does not support that <it>RIP140 </it>regulate human obesity.</p

    Expert Consideration on Regulatory Aspects for Perinatal Derivatives in Clinical Settings.

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    Perinatal derivatives (PnD) are drawing growing interest among the scientific community as an unrestricted source of multipotent stem cells, secretome, and biological matrices. They are useful for the treatment of diseases that currently have limited or no effective therapeutic options, but they require the development of regenerative approaches. With this development, the question of regulation of donation, processing, and distribution has therefore become more important. Within the European Cooperation in Science and Technology (COST) community, we compiled a group of international experts on PnD technologies, who revised and compared existing EU national regulations. Notably, despite clear European directives, each EU Country has developed their own implementation and standard levels for cell- and tissue-based therapies. To enable extended applications of PnD treatments within the EU community and worldwide, harmonization is highly recommended. This paper aims to provide an overview of the various options available to introduce PnD into clinical practice. For this purpose, the different aspects resulting from (1) the type of PnD, (2) the amount of available data, (3) the degree of manipulation, and (4) the intended application and the process toward a possible commercialization will be presented. In the future, it will be important to find a balance between regulatory requirements and the best medical quality of the PnD product

    Harmonizing methods for wildlife abundance estimation and pathogen detection in Europe-a questionnaire survey on three selected host-pathogen combinations

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    __Background:__ The need for wildlife health surveillance as part of disease control in wildlife, domestic animals and humans on the global level is widely recognized. However, the objectives, methods and intensity of existing wildlife health surveillance programs vary greatly among European countries, resulting in a patchwork of data that are difficult to merge and compare. This survey aimed at evaluating the need and potential for data harmonization in wildlife health in Europe. The specific objective was to collect information on methods currently used to estimate host abundance and pathogen prevalence. Questionnaires were designed t

    Cystathionine beta-synthase mutants exhibit changes in protein unfolding: conformational analysis of misfolded variants in crude cell extracts

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    Protein misfolding has been proposed to be a common pathogenic mechanism in many inborn errors of metabolism including cystathionine ÎČ-synthase (CBS) deficiency. In this work, we describe the structural properties of nine CBS mutants that represent a common molecular pathology in the CBS gene. Using thermolysin in two proteolytic techniques, we examined conformation of these mutants directly in crude cell extracts after expression in E. coli. Proteolysis with thermolysin under native conditions appeared to be a useful technique even for very unstable mutant proteins, whereas pulse proteolysis in a urea gradient had limited values for the study of the majority of CBS mutants due to their instability. Mutants in the active core had either slightly increased unfolding (p.A114V, p.E302K and p.G307S) or extensive unfolding with decreased stability (p.H65R, p.T191M, p.I278T and p.R369C). The extent of the unfolding inversely correlated with the previously determined degree of tetrameric assembly and with the catalytic activity. In contrast, mutants bearing aminoacid substitutions in the C-terminal regulatory domain (p.R439Q and p.D444N) had increased global stability with decreased flexibility. This study shows that proteolytic techniques can reveal conformational abnormalities even for CBS mutants that have activity and/or a degree of assembly similar to the wild-type enzyme. We present here a methodological strategy that may be used in cell lysates to evaluate properties of proteins that tend to misfold and aggregate and that may be important for conformational studies of disease-causing mutations in the field of inborn errors of metabolism
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