127 research outputs found

    Thermodynamic Analysis for the Selection of low GWP Refrigerants in Ground Source Heat Pumps

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    One of the main objectives of the European Commission in the buildings sector, responsible for approximately 40% of total energy consumption and 36% of greenhouse gas emissions, is to identify technological solutions capable of reducing energy consumption and at the same time greenhouse gas emissions. For this purpose, ground source heat pump system (GSHPs) is a technology of particular interest that promises to considerably reduce greenhouse gas emissions of HVAC systems (up to 44% compared to air source heat pumps). In order to develop and test innovative GSHPs to be used for heating and cooling in the various European climatic zones, EU has funded the GEO4CIVHIC project, which will have a duration of 4 years and will end in 2022. As part of the project, the problem of identifying new generation low environmental impact refrigerants to be used in innovative GSHPs is tackled. In this article, we report the results of an energetic and exergetic analysis of the performance of heat pumps based on simulations carried out both on simple reverse cycles and on more complex cycles. Low pressure alternative fluids have been considered as an alternative to R134a and high pressure fluids as an alternative to R410A. The simulations were conducted at various heat sink and heat source temperature conditions, in order to evaluate the GSHPs performance in the whole range of real conditions that can be found in Europe. Particular attention was paid to the compression phase, with the aim to simulate the compressor performance in a more realistic way than simply assuming constant isentropic efficiency

    {\AA}ngstr\"om-resolved Interfacial Structure in Organic-Inorganic Junctions

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    Charge transport processes at interfaces which are governed by complex interfacial electronic structure play a crucial role in catalytic reactions, energy storage, photovoltaics, and many biological processes. Here, the first soft X-ray second harmonic generation (SXR-SHG) interfacial spectrum of a buried interface (boron/Parylene-N) is reported. SXR-SHG shows distinct spectral features that are not observed in X-ray absorption spectra, demonstrating its extraordinary interfacial sensitivity. Comparison to electronic structure calculations indicates a boron-organic separation distance of 1.9 {\AA}, wherein changes as small as 0.1 {\AA} result in easily detectable SXR-SHG spectral shifts (ca. 100s of meV). As SXR-SHG is inherently ultrafast and sensitive to individual atomic layers, it creates the possibility to study a variety of interfacial processes, e.g. catalysis, with ultrafast time resolution and bond specificity.Comment: 19 page

    Evidence that Prefibrotic Myelofibrosis Is Aligned along a Clinical and Biological Continuum Featuring Primary Myelofibrosis

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    PURPOSE: In the WHO diagnostic classification, prefibrotic myelofibrosis (pre-MF) is included in the category of primary myelofibrosis (PMF). However, strong evidence for this position is lacking. PATIENTS AND METHODS: We investigated whether pre-MF may be aligned along a clinical and biological continuum in 683 consecutive patients who received a WHO diagnosis of PMF. RESULTS: As compared with PMF-fibrotic type, pre-MF (132 cases) showed female dominance, younger age, higher hemoglobin, higher platelet count, lower white blood cell count, smaller spleen index and higher incidence of splanchnic vein thrombosis. Female to male ratio and hemoglobin steadily decreased, while age increased from pre-MF to PMF- fibrotic type with early and to advanced bone marrow (BM) fibrosis. Likely, circulating CD34+ cells, LDH levels, and frequency of chromosomal abnormalities increased, while CXCR4 expression on CD34+ cells and serum cholesterol decreased along the continuum of BM fibrosis. Median survival of the entire cohort of PMF cases was 21 years. Ninety-eight, eighty-one and fifty-six percent of patients with pre-MF, PMF-fibrotic type with early and with advanced BM fibrosis, respectively, were alive at 10 years from diagnosis. CONCLUSION: Pre-MF is a presentation mode of PMF with a very indolent phenotype. The major consequences of this contention is a new clinical vision of PMF, and the need to improve prognosis prediction of the disease

    BNC2 is a putative tumor suppressor gene in high-grade serous ovarian carcinoma and impacts cell survival after oxidative stress

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    Rs3814113 is the single-nucleotide polymorphism (SNP) showing the strongest association with high-grade serous ovarian carcinoma (HGSOC) incidence and is located in an intergenic region about 44\u2009kb downstream of basonuclin 2 (BNC2) gene. Lifetime number of ovulations is associated with increased risk to develop HGSOC, probably because of cell damage of extrauterine M\ufcllerian epithelium by ovulation-induced oxidative stress. However, the impact of low-penetrance HGSOC risk alleles (e.g. rs3814113) on the damage induced by oxidative stress remains unclear. Therefore, the purpose of this study was to investigate whether rs3814113 genetic interval regulates BNC2 expression and whether BNC2 expression levels impact on cell survival after oxidative stress. To do this, we analyzed gene expression levels of BNC2 first in HGSOC data sets and then in an isogenic cell line that we engineered to carry a 5\u2009kb deletion around rs3814113. Finally, we silenced BNC2 and measured surviving cells after hydrogen peroxide (H2O2) treatment to simulate oxidative stress after ovulation. In this paper, we describe that BNC2 expression levels are reduced in HGSOC samples compared with control samples, and that BNC2 expression levels decrease following oxidative stress and ovulation in vitro and in vivo, respectively. Moreover, deletion of 5\u2009kb surrounding rs3814113 decreases BNC2 expression levels in an isogenic cell line, and silencing of BNC2 expression levels increases cell survival after H2O2 treatment. Altogether, our findings suggest that the intergenic region located around rs3814113 regulates BNC2 expression, which in turn affects cell survival after oxidative stress response. Indeed, HGSOC samples present lower BNC2 expression levels that probably, in the initial phases of oncogenic transformation, conferred resistance to oxidative stress and ultimately reduced the clearance of cells with oxidative-induced damages

    Chemical, Physical And Oxidative Characteristics Of Broilers Meat Supplemented With Passion Fruit Seed Oil

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    Residues that could be discarded and transformed in high biological value protein is a measure of environmental preservation combined with the sustainability of animal production. This study evaluated the effects of the addition of passion fruit seed oil (PFSO) on broiler diet under the resistance of skin, physical-chemical characteristic, fatty acid profile and lipid oxidation (under storage) of breast meat obtained from these animals. There was improvement in the condition of skin rupture and meat tenderness; apart from that, oxidative reactions decreased, as PFSO was added to the diet (P<0.05). On the other hand, no effect on colour, pH, water retention capacity and weight loss on cooking (P>0.05) was observed. There was a linear effect increasing only for the margaric (C17:0) and cis10-Heptadecanoic (C17:1; P<0,05) fatty acids. However, due to the low amount of these fatty acids in PFSO, the found content was still low in all evaluated treatments. However, the evaluated levels did not contribute to the increase of the polyunsaturated fatty acid profile (P>0.05). Thus, it can be concluded that PFSO improves the resistance of broiler skin, which becomes softer and less susceptible to oxidative effects due to the oil’s antioxidant action, suggesting that it may be an ingredient that brings substantial benefits in the poultry industry

    Burnout Syndrome In Municipal Health Managers

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    Os gestores municipais da saĂșde devem responder Ă s demandas de suas equipes e dos pacientes do Sistema Único de SaĂșde, enfrentando cotidianamente situaçÔes potencialmente estressoras. A sobrecarga no trabalho pode levar Ă  exaustĂŁo fĂ­sica e mental, com esgotamento dos recursos emocionais, e desencadear a SĂ­ndrome de Burnout (SB), cujas consequĂȘncias podem atingir o serviço gerenciado, uma vez que, ao desempenhar essa atividade laboral, tomam-se decisĂ”es determinantes nas açÔes em saĂșde que afetam muitas pessoas. Este estudo verificou a presença da SB nos gestores municipais de saĂșde do Estado de SĂŁo Paulo. MĂ©todos Estudo do tipo transversal no qual foram coletados dados socioeconĂŽmicos e demogrĂĄficos. Os nĂ­veis de SB foram avaliados pela aplicação do Cuestionario para la EvaluaciĂłn del SĂ­ndrome de Quemarse por el Trabajo (CESQT). A anĂĄlise descritiva foi realizada por meio do cĂĄlculo de frequĂȘncias. Resultados Verificou-se baixa prevalĂȘncia de SB entre os 199 gestores participantes do estudo. PorĂ©m houve casos indicativos da presença da SB, inclusive com caracterĂ­sticas de Perfil 2. ConclusĂŁo Esses achados evidenciam que essa classe de profissionais necessita de atenção e cuidados para prevenção e controle das consequĂȘncias da SB, a fim de evitar que pessoas doentes gerenciem serviços de saĂșde.24220921

    Transcriptomic and photosynthetic analyses of Synechocystis sp. PCC6803 and Chlorogloeopsis fritschii sp. PCC6912 exposed to an M-dwarf spectrum under an anoxic atmosphere

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    IntroductionCyanobacteria appeared in the anoxic Archean Earth, evolving for the first time oxygenic photosynthesis and deeply changing the atmosphere by introducing oxygen. Starting possibly from UV-protected environments, characterized by low visible and far-red enriched light spectra, cyanobacteria spread everywhere on Earth thanks to their adaptation capabilities in light harvesting. In the last decade, few cyanobacteria species which can acclimate to far-red light through Far-Red Light Photoacclimation (FaRLiP) have been isolated. FaRLiP cyanobacteria were thus proposed as model organisms to study the origin of oxygenic photosynthesis as well as its possible functionality around stars with high far-red emission, the M-dwarfs. These stars are astrobiological targets, as their longevity could sustain life evolution and they demonstrated to host rocky terrestrial-like exoplanets within their Habitable Zone.MethodsWe studied the acclimation responses of the FaRLiP strain Chlorogloeopsis fritschii sp. PCC6912 and the non-FaRLiP strain Synechocystis sp. PCC6803 to the combination of three simulated light spectra (M-dwarf, solar and far-red) and two atmospheric compositions (oxic, anoxic). We first checked their growth, O2 production and pigment composition, then we studied their transcriptional responses by RNA sequencing under each combination of light spectrum and atmosphere conditions.Results and discussionPCC6803 did not show relevant differences in gene expression when comparing the responses to M-dwarf and solar-simulated lights, while far-red caused a variation in the transcriptional level of many genes. PCC6912 showed, on the contrary, different transcriptional responses to each light condition and activated the FaRLiP response under the M-dwarf simulated light. Surprisingly, the anoxic atmosphere did not impact the transcriptional profile of the 2 strains significantly. Results show that both cyanobacteria seem inherently prepared for anoxia and to harvest the photons emitted by a simulated M-dwarf star, whether they are only visible (PCC6803) or also far-red photons (PCC6912). They also show that visible photons in the simulated M-dwarf are sufficient to keep a similar metabolism with respect to solar-simulated light.ConclusionResults prove the adaptability of the cyanobacterial metabolism and enhance the plausibility of finding oxygenic biospheres on exoplanets orbiting M-dwarf stars
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