97 research outputs found

    On the selection and design of proteins and peptide derivatives for the production of photoluminescent, red-emitting gold quantum clusters

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    Novel pathways of the synthesis of photoluminescent gold quantum clusters (AuQCs) using biomolecules as reactants provide biocompatible products for biological imaging techniques. In order to rationalize the rules for the preparation of red-emitting AuQCs in aqueous phase using proteins or peptides, the role of different organic structural units was investigated. Three systems were studied: proteins, peptides, and amino acid mixtures, respectively. We have found that cysteine and tyrosine are indispensable residues. The SH/S-S ratio in a single molecule is not a critical factor in the synthesis, but on the other hand, the stoichiometry of cysteine residues and the gold precursor is crucial. These observations indicate the importance of proper chemical behavior of all species in a wide size range extending from the atomic distances (in the AuI-S semi ring) to nanometer distances covering the larger sizes of proteins assuring the hierarchical structure of the whole self-assembled system

    Descriptive analysis of childbirth healthcare costs in an area with high levels of immigration in Spain

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to estimate the cost of childbirth in a teaching hospital in Barcelona, Spain, including the costs of prenatal care, delivery and postnatal care (3 months). Costs were assessed by taking into account maternal origin and delivery type.</p> <p>Methods</p> <p>We performed a cross-sectional study of all deliveries in a teaching hospital to mothers living in its catchment area between October 2006 and September 2007. A process cost analysis based on a full cost accounting system was performed. The main information sources were the primary care program for sexual and reproductive health, and hospital care and costs records. Partial and total costs were compared according to maternal origin and delivery type. A regression model was fit to explain the total cost of the childbirth process as a function of maternal age and origin, prenatal care, delivery type, maternal and neonatal severity, and multiple delivery.</p> <p>Results</p> <p>The average cost of childbirth was 4,328€, with an average of 18.28 contacts between the mother or the newborn and the healthcare facilities. The delivery itself accounted for more than 75% of the overall cost: maternal admission accounted for 57% and neonatal admission for 20%. Prenatal care represented 18% of the overall cost and 75% of overall acts. The average overall cost was 5,815€ for cesarean sections, 4,064€ for vaginal instrumented deliveries and 3,682€ for vaginal non-instrumented deliveries (p < 0.001). The regression model explained 45.5% of the cost variability. The incremental cost of a delivery through cesarean section was 955€ (an increase of 31.9%) compared with an increase of 193€ (6.4%) for an instrumented vaginal delivery. The incremental cost of admitting the newborn to hospital ranged from 420€ (14.0%) to 1,951€ (65.2%) depending on the newborn's severity. Age, origin and prenatal care were not statistically significant or economically relevant.</p> <p>Conclusions</p> <p>Neither immigration nor prenatal care were associated with a substantial difference in costs. The most important predictors of cost were delivery type and neonatal severity. Given the impact of cesarean sections on the overall cost of childbirth, attempts should be made to take into account its higher cost in the decision of performing a cesarean section.</p

    Increased Membrane Cholesterol in Lymphocytes Diverts T-Cells toward an Inflammatory Response

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    Cell signaling for T-cell growth, differentiation, and apoptosis is initiated in the cholesterol-rich microdomains of the plasma membrane known as lipid rafts. Herein, we investigated whether enrichment of membrane cholesterol in lipid rafts affects antigen-specific CD4 T-helper cell functions. Enrichment of membrane cholesterol by 40–50% following squalene administration in mice was paralleled by an increased number of resting CD4 T helper cells in periphery. We also observed sensitization of the Th1 differentiation machinery through co-localization of IL-2Rα, IL-4Rα, and IL-12Rβ2 subunits with GM1 positive lipid rafts, and increased STAT-4 and STAT-5 phosphorylation following membrane cholesterol enrichment. Antigen stimulation or CD3/CD28 polyclonal stimulation of membrane cholesterol-enriched, resting CD4 T-cells followed a path of Th1 differentiation, which was more vigorous in the presence of increased IL-12 secretion by APCs enriched in membrane cholesterol. Enrichment of membrane cholesterol in antigen-specific, autoimmune Th1 cells fostered their organ-specific reactivity, as confirmed in an autoimmune mouse model for diabetes. However, membrane cholesterol enrichment in CD4+ Foxp3+ T-reg cells did not alter their suppressogenic function. These findings revealed a differential regulatory effect of membrane cholesterol on the function of CD4 T-cell subsets. This first suggests that membrane cholesterol could be a new therapeutic target to modulate the immune functions, and second that increased membrane cholesterol in various physiopathological conditions may bias the immune system toward an inflammatory Th1 type response

    A framework for the development of a global standardised marine taxon reference image database (SMarTaR-ID) to support image-based analyses

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    Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure maps to the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem

    LIF-Dependent Signaling: New Pieces in the Lego

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    LIF, a member of the IL6 family of cytokine, displays pleiotropic effects on various cell types and organs. Its critical role in stem cell models (e.g.: murine ES, human mesenchymal cells) and its essential non redundant function during the implantation process of embryos, in eutherian mammals, put this cytokine at the core of many studies aiming to understand its mechanisms of action, which could benefit to medical applications. In addition, its conservation upon evolution raised the challenging question concerning the function of LIF in species in which there is no implantation. We present the recent knowledge about the established and potential functions of LIF in different stem cell models, (embryonic, hematopoietic, mesenchymal, muscle, neural stem cells and iPSC). We will also discuss EVO-DEVO aspects of this multifaceted cytokine

    Male-biased gastrointestinal parasitism in a nearly monomorphic mountain ungulate

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    Background: Pyrenean chamois (Rupicapra pyrenaica pyrenaica) is a nearly monomorphic mountain ungulate with an unbiased sex-specific overwinter adult survival. Few differences in gastrointestinal parasitism have been reported by coprology as yet. This study aims to assess diversity, prevalence, intensity of infection and aggregation of gastrointestinal nematodes in male and female adult chamois. We expect no differences in the parasite infection rates between sexes. Findings: Gastrointestinal tracts of 28 harvested Pyrenean chamois in the Catalan Pyrenees (autumn 2012 and 2013) were necropsied and sexual differences in the diversity and structure of parasite community, prevalence, intensity of infection, and richness were investigated. We found 25 helminth species belonging to 13 different genera. Conclusions: Contrary to our expectations, male chamois showed different parasite communities, higher prevalence, intensity of infection and richness than females. Such sexual differences were clear irrespective of age of individuals. Hence, male chamois must cope with a more diverse and abundant parasite community than females, without apparent biological cost. Further research will be required to confirm this hypothesis
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