311 research outputs found

    Update of the European paediatric respiratory medicine syllabus

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    The 10-year-old European syllabus for paediatric respiratory medicine (PRM; also known as paediatric pulmonology) was updated by a consensus-based method using an expert task force for redrafting, and a subsequent Delphi process to achieve consensus. There was a high degree of consensus for the final syllabus, which has been streamlined and made more relevant to current practice. All modules are now mandatory apart from the undertaking of research projects, which is optional. Although there are still a number of countries in Europe which do not recognise PRM as a separate subspecialty, there are paediatric respiratory physicians practising in every country in Europe, and a current and harmonised European syllabus in the subspecialty remains important for defining the training and areas of practice of PRM practitioners

    Thermal and optical characterization of tetrathylene glycol -based solar nanofluid at high temperature conditions

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    Nanofluids are defined as dilute suspensions with solid particles smaller than 100 nm. Nanofluids present some important advantages over the conventional colloidal suspensions such as high stability, reduced particle clogging and high heat transfer capabilities. Most of published works have been focused on the increment of thermal conductivity in water-based nanofluids with high nanoparticle loads. Solar nanofluids are a type of nanofluids with low nanoparticle loads and suitable for direct solar radiation harvesting. In this case, nanoparticles in the heat transfer fluid directly absorbs the solar radiation, transferring the heat to the heat transfer fluid. In this way, high efficiency from solar radiation to thermal energy can be obtained since the heat exchange area (nanoparticle surface area) is extremely high and the peak temperature is inside the heat transfer fluid. In most published works, thermal and optical characterizations of solar nanofluids are performed at room temperature conditions, far away from experimental conditions found in real applications. In this work, a complete thermal and optical characterization of a tetraethylene glycol – based nanofluid using tin nanoparticles have been performed. Nanoparticle morphology and nanoparticle cluster size have been characterized at room conditions and thermal conductivity, specific heat capacity and transmission spectrum have been measured at different temperatures between 50ºC and 150ºC. Nanoparticle morphology has been characterized by Transmission Electron Microscope and cluster size by Dynamic Light Scattering technique, thermal conductivity have been measured by the hot wire technique, the specific heat capacity by a Differential Scanning Calorimeter and the transmission spectrum by a fiber optic based spectrometer and a special designed nanofluid cuvette with controlled temperature conditions.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

    Are congenital malformations more frequent in fetuses with intrahepatic persistent right umbilical vein? A comparative study

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    Objective Persistent right umbilical vein (PRUV) is a vascular anomaly where the right umbilical vein remains as the only conduit that returns oxygenated blood to the fetus. It has classically been described as associated with numerous defects. We distinguish the intrahepatic variant (better prognosis) and the extrahepatic variant (associated with worse prognosis). The objective of this study was to compare rates of congenital malformations in fetuses with intrahepatic PRUV (I-PRUV) versus singleton pregnancies without risk factors. Materials and Methods A multicenter, crossover design, comparative study was performed between 2003 and 2013 on fetuses diagnosed with I-PRUV (n = 56), and singleton pregnancies without congenital malformation risk factors (n = 4050). Results Fifty-six cases of I-PRUV were diagnosed (incidence 1:770). A statistically significant association between I-PRUV and the presence of congenital malformations (odds ratio 4.321; 95% confidence interval 2.15–8.69) was found. This positive association was only observed with genitourinary malformations (odds ratio 3.038; 95% confidence interval 1.08–8.56). Conclusion Our rate of malformations associated with I-PRUV (17.9%) is similar to previously published rates. I-PRUV has shown a significant increase in the rate of associated malformations, although this association has only been found to be statistically significant in the genitourinary system. Noteworthy is the fact that this comparative study has not pointed to a significant increase in the congenital heart malformation rate. Diagnosis of isolated I-PRUV does not carry a worse prognosis

    An element through the looking glass: Exploring the Au-C, Au-H and Au-O energy landscape

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    Gold, the archetypal “noble metal”, used to be considered of little interest in catalysis. It is now clear that this was a misconception, and a multitude of gold-catalysed transformations has been reported. However, one consequence of the long-held view of gold as inert metal is that its organometallic chemistry contains many “unknowns”, and catalytic cycles devised to explain gold's reactivity draw largely on analogies with other transition metals. How realistic are such mechanistic assumptions? In the last few years a number of key compound classes have been discovered that can provide some answers. This Perspective attempts to summarise these developments, with particular emphasis on recently discovered gold(III) complexes with bonds to hydrogen, oxygen, alkenes and CO ligands

    Changes in Cardiac Substrate Transporters and Metabolic Proteins Mirror the Metabolic Shift in Patients with Aortic Stenosis

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    In the hypertrophied human heart, fatty acid metabolism is decreased and glucose utilisation is increased. We hypothesized that the sarcolemmal and mitochondrial proteins involved in these key metabolic pathways would mirror these changes, providing a mechanism to account for the modified metabolic flux measured in the human heart. Echocardiography was performed to assess in vivo hypertrophy and aortic valve impairment in patients with aortic stenosis (n = 18). Cardiac biopsies were obtained during valve replacement surgery, and used for western blotting to measure metabolic protein levels. Protein levels of the predominant fatty acid transporter, fatty acid translocase (FAT/CD36) correlated negatively with levels of the glucose transporters, GLUT1 and GLUT4. The decrease in FAT/CD36 was accompanied by decreases in the fatty acid binding proteins, FABPpm and H-FABP, the β-oxidation protein medium chain acyl-coenzyme A dehydrogenase, the Krebs cycle protein α-ketoglutarate dehydrogenase and the oxidative phosphorylation protein ATP synthase. FAT/CD36 and complex I of the electron transport chain were downregulated, whereas the glucose transporter GLUT4 was upregulated with increasing left ventricular mass index, a measure of cardiac hypertrophy. In conclusion, coordinated downregulation of sequential steps involved in fatty acid and oxidative metabolism occur in the human heart, accompanied by upregulation of the glucose transporters. The profile of the substrate transporters and metabolic proteins mirror the metabolic shift from fatty acid to glucose utilisation that occurs in vivo in the human heart

    Multiple TORC1-Associated Proteins Regulate Nitrogen Starvation-Dependent Cellular Differentiation in Saccharomyces cerevisiae

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    The budding yeast Saccharomyces cerevisiae undergoes differentiation into filamentous-like forms and invades the growth medium as a foraging response to nutrient and environmental stresses. These developmental responses are under the downstream control of effectors regulated by the cAMP/PKA and MAPK pathways. However, the upstream sensors and signals that induce filamentous growth through these signaling pathways are not fully understood. Herein, through a biochemical purification of the yeast TORC1 (Target of Rapamycin Complex 1), we identify several proteins implicated in yeast filamentous growth that directly associate with the TORC1 and investigate their roles in nitrogen starvation-dependent or independent differentiation in yeast.We isolated the endogenous TORC1 by purifying tagged, endogenous Kog1p, and identified associated proteins by mass spectrometry. We established invasive and pseudohyphal growth conditions in two S. cerevisiae genetic backgrounds (Σ1278b and CEN.PK). Using wild type and mutant strains from these genetic backgrounds, we investigated the roles of TORC1 and associated proteins in nitrogen starvation-dependent diploid pseudohyphal growth as well as nitrogen starvation-independent haploid invasive growth.We show that several proteins identified as associated with the TORC1 are important for nitrogen starvation-dependent diploid pseudohyphal growth. In contrast, invasive growth due to other nutritional stresses was generally not affected in mutant strains of these TORC1-associated proteins. Our studies suggest a role for TORC1 in yeast differentiation upon nitrogen starvation. Our studies also suggest the CEN.PK strain background of S. cerevisiae may be particularly useful for investigations of nitrogen starvation-induced diploid pseudohyphal growth

    Interdigital cell death in the embryonic limb is associated with depletion of Reelin in the extracellular matrix

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    Interdigital cell death is a physiological regression process responsible for sculpturing the digits in the embryonic vertebrate limb. Changes in the intensity of this degenerative process account for the different patterns of interdigital webbing among vertebrate species. Here, we show that Reelin is present in the extracellular matrix of the interdigital mesoderm of chick and mouse embryos during the developmental stages of digit formation. Reelin is a large extracellular glycoprotein which has important functions in the developing nervous system, including neuronal survival; however, the significance of Reelin in other systems has received very little attention. We show that reelin expression becomes intensely downregulated in both the chick and mouse interdigits preceding the establishment of the areas of interdigital cell death. Furthermore, fibroblast growth factors, which are cell survival signals for the interdigital mesoderm, intensely upregulated reelin expression, while BMPs, which are proapototic signals, downregulate its expression in the interdigit. Gene silencing experiments of reelin gene or its intracellular effector Dab-1 confirmed the implication of Reelin signaling as a survival factor for the limb undifferentiated mesoderm. We found that Reelin activates canonical survival pathways in the limb mesoderm involving protein kinase B and focal adhesion kinase. Our findings support that Reelin plays a role in interdigital cell death, and suggests that anoikis (apoptosis secondary to loss of cell adhesion) may be involved in this process

    Sustained proliferation in cancer: mechanisms and novel therapeutic targets

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    Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression
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