211 research outputs found

    Neonatal events, such as androgenization and postnatal overfeeding, modify the response to ghrelin

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    It is currently accepted that ambient, non-genetic factors influence perinatal development and evoke structural and functional changes that may persist throughout life. Overfeeding and androgenization after birth are two of these key factors that could result in "metabolic imprinting" of neuronal circuits early in life and, thereby, increase the body weight homeostatic "set point", stimulate appetite, and result in obesity. Our aim was to determine the influence of these obesogenic factors on the response to ghrelin. We observed the expected orexigenic effect of ghrelin regardless of the nutritional or hormonal manipulations to which the animals were subjected to at early postnatal development and this effect remained intact at later stages of development. In fact, ghrelin responses increased significantly when the animals were subjected to one of the two manipulations, but not when both were combined. An increased response to ghrelin could explain the obese phenotype displayed by individuals with modified perinatal environment.Ministerio de Educacion y CienciaInstituto de Salud Carlos IIIEuropean Community´s Seventh Framework Programm

    Tool wear in the dry drilling of TÍ-6AI-4V: a SEM/EDS study

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    En este artículo se estudia el proceso de taladrado sin fluido de corte, de la aleación Ti6A14V, comparando dos condiciones de mecanizado, con y sin enfriamiento de herramienta y material entre taladros. El objetivo de este trabajo es analizar la influencia en el desgaste de la herramienta y en la calidad del agujero, del diferente incremento de temperatura originado por trabajar en una u otra condición. Para ello, se realizará análisis SEM/EDS y microscopía óptica de la broca e inspección visual del material.This paper is focused on dry drilling of Ti6Al4V. In absence of cutting fluid, high temperatures are reached. Two different cutting conditions are studied in order to analyse the influence of temperature. In first condition, tests with no pause between drilled holes were carried out. In second condition, tests were performed cooling the tool with air between consecutively holes. Tool wear was studied with optical microscope and SEM-EDS techniques. The quality of machined holes was estimated in terms of optical inspection. Significantly differences in tool wear evolution were observed between both cutting conditions analysed.Este trabajo ha sido financiado por la Comisión Interministerial de Ciencia y Tecnología (CICYT) proyecto DPI2001-3747, por AIRBUS España, S.L. y por la Junta de Andalucía. Los autores agrádecen al Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica de la Universidad Carlos III de Madrid su ayuda y la disponibilidad de sus equipos para la realización de los estudios de microscopía óptica y SEM/EDS.Publicad

    Changes in hypothalamic expression of the Lin28/let-7 system and related MicroRNAs during postnatal maturation and after experimental manipulations of puberty

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    [Abstract] Lin28 and Lin28b are related RNA-binding proteins that inhibit the maturation of miRNAs of the let-7 family and participate in the control of cellular stemness and early embryonic development. Considerable interest has arisen recently concerning other physiological roles of the Lin28/let-7 axis, including its potential involvement in the control of puberty, as suggested by genome-wide association studies and functional genomics. We report herein the expression profiles of Lin28 and let-7 members in the rat hypothalamus during postnatal maturation and in selected models of altered puberty. The expression patterns of c-Myc (upstream positive regulator of Lin28), mir-145 (negative regulator of c-Myc), and mir-132 and mir-9 (putative miRNA repressors of Lin28, predicted by bioinformatic algorithms) were also explored. In male and female rats, Lin28, Lin28b, and c-Myc mRNAs displayed very high hypothalamic expression during the neonatal period, markedly decreased during the infantile-to-juvenile transition and reached minimal levels before/around puberty. A similar puberty-related decline was observed for Lin28b in monkey hypothalamus but not in the rat cortex, suggesting species conservation and tissue specificity. Conversely, let-7a, let-7b, mir-132, and mir-145, but not mir-9, showed opposite expression profiles. Perturbation of brain sex differentiation and puberty, by neonatal treatment with estrogen or androgen, altered the expression ratios of Lin28/let-7 at the time of puberty. Changes in the c-Myc/Lin28b/let-7 pathway were also detected in models of delayed puberty linked to early photoperiod manipulation and, to a lesser extent, postnatal underfeeding or chronic subnutrition. Altogether, our data are the first to document dramatic changes in the expression of the Lin28/let-7 axis in the rat hypothalamus during the postnatal maturation and after different manipulations that disturb puberty, thus suggesting the potential involvement of developmental changes in hypothalamic Lin28/let-7 expression in the mechanisms permitting/leading to puberty onset.Ministerio de Economia y Competitividad; BFU 2008-00984Ministerio de Economia y Competitividad; BFU 2011-25021Junta de Andalucía; P08-CVI-03788United States. National Institutes of Health HD025123-ARRAUnited States. National Science Foundation; IOS1121691Instituto de Salud Carlos III; PI10/00088Xunta de Galicia; IN845B-2010/187Xunta de Galicia; 10CSA916014P

    Adrenomedullin as a potential biomarker involved in patients with hereditary hemorrhagic telangiectasia

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    Background: Adrenomedullin (AM) is a vasoactive peptide mostly secreted by endothelial cells with an important role in preserving endothelial integrity. The relationship between AM and hereditary hemorrhagic telangiectasia (HHT) is unknown. We aimed to compare the serum levels and tissue expression of AM between HHT patients and controls. Methods: Serum AM levels were measured by radioimmunoassay and compared between control and HHT groups. AM levels were also compared among HHT subgroups according to clinical characteristics. The single nucleotide polymorphism (SNP) rs4910118 was assessed by restriction analysis and sequencing. AM immunohistochemistry was performed on biopsies of cutaneous telangiectasia from eight HHT patients and on the healthy skin from five patients in the control group. Results: Forty-five HHT patients and 50 healthy controls were included, mean age (SD) was 50.7 (14.9) years and 46.4 (9.9) years (p = 0.102), respectively. HHT patients were mostly female (60% vs 38%, p = 0.032). Median [Q1-Q3] serum AM levels were 68.3 [58.1-80.6] pg/mL in the HHT group and 47.7 [43.2-53.8] pg/mL in controls (p<0.001), with an optimal AM cut-off according to Youden's J statistic of 55.32 pg/mL (J:0.729). Serum AM levels were similar in the HHT subgroups. No patient with HHT had the SNP rs4910118. AM immunoreactivity was found with high intensity in the abnormal blood vessels of HHT biopsies

    Effects on short term outcome of non-invasive ventilation use in the emergency department to treat patients with acute heart failure: A propensity score-based analysis of the EAHFE Registry

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    Objective: To assess the effects of non-invasive ventilation (NIV) in emergency department (ED) patients with acute heart failure (AHF) on short term outcomes. Methods: Patients from the EAHFE Registry (a multicenter, observational, multipurpose, cohort-designed database including consecutive AHF patients in 41 Spanish EDs) were grouped based on NIV treatment (NIV+ and NIV–groups). Using propensity score (PS) methodology, we identified two subgroups of patients matched by 38 covariates and compared regarding 30-day survival (primary outcome). Interaction was investigated for age, sex, ischemic cardiomyopathy, chronic obstructive pulmonary disease, AHF precipitated by an acute coronary syndrome (ACS), AHF classified as hypertensive or acute pulmonary edema (APE), and systolic blood pressure (SBP). Secondary outcomes were intensive care unit (ICU) admission; mechanical ventilation; in-hospital, 3-day and 7-day mortality; and prolonged hospitalization (>7 days). Results: Of 11, 152 patients from the EAHFE (age (SD): 80 (10) years; 55.5% women), 718 (6.4%) were NIV+ and had a higher 30-day mortality (HR = 2.229; 95%CI = 1.861–2.670) (p 85 years, p < 0.001), AHF associated with ACS (p = 0.045), and SBP < 100 mmHg (p < 0.001). No significant differences were found in the secondary endpoints except for more prolonged hospitalizations in NIV+ patients (OR = 1.445; 95%CI = 1.122–1.862) (p = 0.004). Conclusion: The use of NIV to treat AHF in ED is not associated with improved mortality outcomes and should be cautious in old patients and those with ACS and hypotension

    Search for the Flavor-Changing Neutral Current Decay D0μ+μD^0 \to \mu^+\mu^- with the HERA-B Detector

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    We report on a search for the flavor-changing neutral current decay D0μ+μD^0 \to \mu^+\mu^- using 50×10650 \times 10^6 events recorded with a dimuon trigger in interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find no evidence for such decays and set a 90% confidence level upper limit on the branching fraction Br(D0μ+μ)<2.0×106Br(D^0 \to \mu^+\mu^-) <2.0 \times 10^{-6}.Comment: 17 pages, 4 figures (of which 1 double), paper to be submitted to Physics Letters

    Measurement of the J/Psi Production Cross Section in 920 GeV/c Fixed-Target Proton-Nucleus Interactions

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    The mid-rapidity (dsigma_(pN)/dy at y=0) and total sigma_(pN) production cross sections of J/Psi mesons are measured in proton-nucleus interactions. Data collected by the HERA-B experiment in interactions of 920 GeV/c protons with carbon, titanium and tungsten targets are used for this analysis. The J/Psi mesons are reconstructed by their decay into lepton pairs. The total production cross section obtained is sigma_(pN)(J/Psi) = 663 +- 74 +- 46 nb/nucleon. In addition, our result is compared with previous measurements

    Influence of the length of hospitalisation in post-discharge outcomes in patients with acute heart failure: Results of the LOHRCA study

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    Objective: To investigate the relationship between length of hospitalisation (LOH) and post-discharge outcomes in acute heart failure (AHF) patients and to ascertain whether there are different patterns according to department of initial hospitalisation. Methods: Consecutive AHF patients hospitalised in 41 Spanish centres were grouped based on the LOH (15 days). Outcomes were defined as 90-day post-discharge all-cause mortality, AHF readmissions, and the combination of both. Hazard ratios (HRs), adjusted by chronic conditions and severity of decompensation, were calculated for groups with LOH >6 days vs. LOH <6 days (reference), and stratified by hospitalisation in cardiology, internal medicine, geriatrics, or short-stay units. Results: We included 8563 patients (mean age: 80 (SD = 10) years, 55.5% women), with a median LOH of 7 days (IQR 4–11): 2934 (34.3%) had a LOH 15 days. The 90-day post-discharge mortality was 11.4%, readmission 32.2%, and combined endpoint 37.4%. Mortality was increased by 36.5% (95%CI = 13.0–64.9) when LOH was 11–15 days, and by 72.0% (95%CI = 42.6–107.5) when >15 days. Conversely, no differences were found in readmission risk, and the combined endpoint only increased 21.6% (95%CI = 8.4–36.4) for LOH >15 days. Stratified analysis by hospitalisation departments rendered similar post-discharge outcomes, with all exhibiting increased mortality for LOH >15 days and no significant increments in readmission risk. Conclusions: Short hospitalisations are not associated with worse outcomes. While post-discharge readmissions are not affected by LOH, mortality risk increases as the LOH lengthens. These findings were similar across hospitalisation departments

    Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

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    Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic
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