911 research outputs found

    Antibacterial activity of crude extracts from Mexican plants against methicillin-resistant Staphylococcus

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    The aim of this study was to evaluate the antimicrobial activity of 36 extracts from 18 vegetal species used as soap, insecticides, insect repellent and for the treatment of several diseases likely associated to microorganisms. The vegetal species were collected in Oaxaca, Puebla and Veracruz States, México. The extracts were evaluated against isolates of nosocomial infections of Staphylococcus aureus and Staphylococcus coagulase negative resistant to Methicillin by a modificated agar diffusion method. The results demonstrate an important antibacterial effect in vitro, against all of the strains of Staphylococcus tested mainly with those from Vernonanthura oaxacana, Trixis silvatica, and with those of Perezia hebeclada. The minimum inhibitory concentration for V. oaxacana and P. hebeclada was 250 μg/disc and for T. silvatica it was 15 μg/disc. These extracts showed an important potential that would contribute to the development of new agents against infections by Staphylococcus.Key words: Crude extracts, antimicrobial activity, intrahospitalary infections, methicillin-resistant Staphylococcus coagulase negative

    Solid lubricant behavior of MoS2 and WSe2-based nanocomposite coatings

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    Tribological coatings made of MoS2 and WSe2 phases and their corresponding combinations with tungsten carbide (WC) were prepared by non-reactive magnetron sputtering of individual targets of similar composition. A comparative tribological analysis of these multiphase coatings was done in both ambient air (30–40% relative humidity, RH) and dry nitrogen (RH<7%) environments using the same tribometer and testing conditions. A nanostructural study using advanced transmission electron microscopy of the initial coatings and examination of the counterfaces after the friction test using different analytical tools helped to elucidate what governs the tribological behavior for each type of environment. This allowed conclusions to be made about the influence of the coating microstructure and composition on the tribological response. The best performance obtained with a WSex film (specific wear rate of 2 × 10−8 mm3 N–1m–1 and a friction coefficient of 0.03–0.05) was compared with that of the well-established MoS2 lubricant material.The Spanish Ministry of Economy, Industry and Competitiveness [projects n° MAT2010-21597-C02-01, MAT2011-29074-C02-01; MAT2015-65539-P; MAT2015-69035-REDC], Junta de Andalucía [P10-TEP-67182] and Spanish National Research Council (CSIC) [201560E013] are acknowledged for their financial support

    A new rhynchocephalian from the late jurassic of Germany with a dentition that is unique amongst tetrapods.

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    Rhynchocephalians, the sister group of squamates (lizards and snakes), are only represented by the single genus Sphenodon today. This taxon is often considered to represent a very conservative lineage. However, rhynchocephalians were common during the late Triassic to latest Jurassic periods, but rapidly declined afterwards, which is generally attributed to their supposedly adaptive inferiority to squamates and/or Mesozoic mammals, which radiated at that time. New finds of Mesozoic rhynchocephalians can thus provide important new information on the evolutionary history of the group. A new fossil relative of Sphenodon from the latest Jurassic of southern Germany, Oenosaurus muehlheimensis gen. et sp. nov., presents a dentition that is unique amongst tetrapods. The dentition of this taxon consists of massive, continuously growing tooth plates, probably indicating a crushing dentition, thus representing a previously unknown trophic adaptation in rhynchocephalians. The evolution of the extraordinary dentition of Oenosaurus from the already highly specialized Zahnanlage generally present in derived rhynchocephalians demonstrates an unexpected evolutionary plasticity of these animals. Together with other lines of evidence, this seriously casts doubts on the assumption that rhynchocephalians are a conservative and adaptively inferior lineage. Furthermore, the new taxon underlines the high morphological and ecological diversity of rhynchocephalians in the latest Jurassic of Europe, just before the decline of this lineage on this continent. Thus, selection pressure by radiating squamates or Mesozoic mammals alone might not be sufficient to explain the demise of the clade in the Late Mesozoic, and climate change in the course of the fragmentation of the supercontinent of Pangaea might have played a major role

    New fixed point theorem under R-contractions

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    In this manuscript we introduce the notions of R-function and R-contractions, and we show an ad hoc fixed point theorem. We prove that this new kind of contractions properly includes the family of all Meir-Keeler contractions and other well-known classes of contractions that have been given very recently (for instance, those using simulation functions and manageable functions). As a consequence, our approach turns out to be appropriate to unify the treatment of different kinds of contractive nonlinear operators.This article was funded by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah. The second author, therefore, acknowledges with thanks DSR for technical and financial support. The authors are grateful to three anonymous referees for their useful suggestions and comments. AF Roldán López de Hierro is grateful to the Department of Quantitative Methods for Economics and Business of the University of Granada. The same author has been partially supported by Junta de Andalucía by project FQM-268 of the Andalusian CICYE

    New insights into the classification and nomenclature of cortical GABAergic interneurons.

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    A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus

    Study protocol of cost-effectiveness and cost-utility of a biopsychosocial multidisciplinary intervention in the evolution of non-specific sub-acute low back pain in the working population: cluster randomised trial.

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain (LBP), with high incidence and prevalence rate, is one of the most common reasons to consult the health system and is responsible for a significant amount of sick leave, leading to high health and social costs. The objective of the study is to assess the cost-effectiveness and cost-utility analysis of a multidisciplinary biopsychosocial educational group intervention (MBEGI) of non-specific sub-acute LBP in comparison with the usual care in the working population recruited in primary healthcare centres. Methods/design: The study design is a cost-effectiveness and cost-utility analysis of a MBEGI in comparison with the usual care of non-specific sub-acute LBP.Measures on effectiveness and costs of both interventions will be obtained from a cluster randomised controlled clinical trial carried out in 38 Catalan primary health care centres, enrolling 932 patients between 18 and 65 years old with a diagnosis of non-specific sub-acute LBP. Effectiveness measures are: pharmaceutical treatments, work sick leave (% and duration in days), Roland Morris disability, McGill pain intensity, Fear Avoidance Beliefs (FAB) and Golberg Questionnaires. Utility measures will be calculated from the SF-12. The analysis will be performed from a social perspective. The temporal horizon is at 3 months (change to chronic LBP) and 12 months (evaluate the outcomes at long term. Assessment of outcomes will be blinded and will follow the intention-to-treat principle. Discussion: We hope to demonstrate the cost-effectiveness and cost-utility of MBEGI, see an improvement in the patients' quality of life, achieve a reduction in the duration of episodes and the chronicity of non-specific low back pain, and be able to report a decrease in the social costs. If the intervention is cost-effectiveness and cost-utility, it could be applied to Primary Health Care Centres. Trial registration: ISRCTN: ISRCTN5871969

    Depression following traumatic brain injury: A functional connectivity perspective.

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    INTRODUCTION: Despite the mounting evidence that depression is one of the most common psychiatric sequelae in survivors of traumatic brain injury (TBI), no studies so far have attempted to provide an explanation in terms of functional network integrity. This proof of concept study investigated the association between the severity of depressive symptoms and resting network integrity in a sample of patients with TBI and a group of healthy controls. METHODS: We first examined the association between depression symptomatology and global functional connectivity and then attempted to characterize the extent of differences in functional network integrity. RESULTS: The severity of depressive symptoms in patients with TBI was associated with neuroadaptations within the insula, the thalamus and the subgenual anterior cingulate cortex (ACC). Specifically, patients with TBI displayed increased connectivity between the insula and a region encompassing the rolandic operculum and the superior temporal cortex and reduced connectivity between the thalamus and the dorsolateral prefrontal cortex. CONCLUSIONS: These findings show the network level involvement of the insula, the thalamus and the subgenual ACC in the depressive symptomatology of patients with TBI and tentatively propose that TBI-induced depression may result from altered functional connectivity of a set of networks associated with emotional regulation. However, other factors including a number of adjustment issues and challenges may also lead to depression in this population.Cambridge, Queens' College, The study was funded by the Evelyn Trust- grant number 06/20. L.M.L. is funded by a Post-Doctoral Fellowship from the University of Granada. A.M. is supported by CLAHRC-East of England awards. D.K.M. is supported by the Neuroscience Theme of the NIHR Cambridge Biomedical Research Centre and NIHR Senior Investigator awards, UK., and by Framework Program 7 funding from the European Commission (TBIcare). E.A.S. is funded by the Stephen Erskine FellowshipThis is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/02699052.2016.118683

    Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

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    Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

    Histone H2A (H2A.X and H2A.Z) Variants in Molluscs: Molecular Characterization and Potential Implications For Chromatin Dynamics

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    Histone variants are used by the cell to build specialized nucleosomes, replacing canonical histones and generating functionally specialized chromatin domains. Among many other processes, the specialization imparted by histone H2A (H2A.X and H2A.Z) variants to the nucleosome core particle constitutes the earliest response to DNA damage in the cell. Consequently, chromatin-based genotoxicity tests have been developed in those cases where enough information pertaining chromatin structure and dynamics is available (i.e., human and mouse). However, detailed chromatin knowledge is almost absent in most organisms, specially protostome animals. Molluscs (which represent sentinel organisms for the study of pollution) are not an exception to this lack of knowledge. In the present work we first identified the existence of functionally differentiated histone H2A.X and H2A.Z variants in the mussel Mytilus galloprovincialis (MgH2A.X and MgH2A.Z), a marine organism widely used in biomonitoring programs. Our results support the functional specialization of these variants based on: a) their active expression in different tissues, as revealed by the isolation of native MgH2A.X and MgH2A.Z proteins in gonad and hepatopancreas; b) the evolutionary conservation of different residues encompassing functional relevance; and c) their ability to confer specialization to nucleosomes, as revealed by nucleosome reconstitution experiments using recombinant MgH2A.X and MgH2A.Z histones. Given the seminal role of these variants in maintaining genomic integrity and regulating gene expression, their preliminary characterization opens up new potential applications for the future development of chromatin-based genotoxicity tests in pollution biomonitoring programs
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