271 research outputs found

    An experimental analysis od the stability and the dynamics of asixymmetric liquid bridges between unequal disks

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    In this paper experimental results related to both stability an the dynamic of a asiximmetric liquid bridge between unequal disk are presented. Experiments have been performed by using a drop tower facility and the response of the liquid bridge to a sudden change of the acceleration level acting on it has bee obtained

    Investigación cualitativa en mujeres víctimas de violencia de género

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    ObjetivoAnalizar la experiencia de mujeres víctimas de la violencia de género atendidas en centros de atención primaria desde el punto de vista de las mujeres.DiseñoInvestigación cualitativa interpretativa. Perspectiva fenomenológica.EmplazamientoEstudio multicéntrico en centros de salud urbanos.ParticipantesMujeres víctimas de la violencia de género (física, psíquica, sexual)atendidas en los centros de salud. Muestreo intencional y teórico hasta el punto de saturación. Criterios de segmentación: edad (jóvenes-edad media-ancianas); maltrato actual o pasado; detección en urgencies-consultas.Mediciones principalesRelatos biográficos y análisis de contenido de la transcripción literal de las grabaciones. Codificación mediante programa NUD-IST. Utilización para la interpretación de la Teoría Fundamentada.LimitacionesComplejidad del fenómeno de estudio. Proyección de la perspectiva del investigador. Volumen ingente de datos. Se proponen estrategias para mejorar la credibilidad, la conformabilidad y la transferibilidad.Aplicabilidad prácticaMejorar el conocimiento de la situación de las mujeres víctimas de la violencia doméstica desde una perspectiva no directiva, lo que permitirá mejorar la calidad de las intervenciones.ObjectiveTo analyse, from the point of view of the women, the experience of women who are victims of male violence and attended at primary care centres.DesignInterpretative, qualitative research. Phenomenological perspective.SettingMulti-centre study in urban health centres.ParticipantsWomen victims of male violence (physical, psychological, or sexual) seen at health centres. Intention andtheoretical sampling to saturation point.Segmentation criteria: age (young/middle-aged/elderly); current or past ill-treatment; detection in casualty/consultations.Main measurementsBiographical accounts and content analysis of recordings’ literal transcription. Coding through the NUDIST programme. Use for interpreting Well-Founded Theory.LimitationsComplexity of the phenomenon under study. Projection of researcher’s perspective. Huge amount of data. Strategies are proposed for increasing credibility, conformity and transferability.Practical useTo improve understanding of the situation of women who are victims of domestic violence, from a non-directive perspective that enables the quality of interventions to be improved

    Interactions between 2,4-bis-pteridine-1,5-benzodiazepine and group 12 dihalides: synthesis, spectral and XRD structural studies and theoretical calculations

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    2,4-Bis(1,3,7-trimethyl-pteridine-2,4(1H,3H)-dione-6-yl)-2,3-dihydro-2-methyl-1H-1,5-benzodiazepine (DLMBZD) has been prepared and its molecular and crystal structures have been determined from spectral and XRD data. The benzodiazepine ligand was reacted with zinc(II), cadmium(II) and mercury(II) chloride, bromide and iodide to give complexes with general formula [M(DLMBZD)X2]. The complexes have been synthesized and characterized by IR, NMR and elemental analysis. The structure of seven complexes has been obtained by single crystal X-ray diffraction. In all the cases, the metal is (2 + 2 + 1)-five-coordinated by two halide ligands, two nitrogen atoms from pyrazine and diazepine rings and a carbonyl oxygen from a pteridine ring. The coordinated-metal environment is a square-based pyramid, with increasing trigonality from Hg(II) to Zn(II) complexes. To coordinate the metals, the ligand folds itself, establishing four intramolecular σ–π interactions with the pyrimidine and pyrazine rings. A topological analysis of the electron density using the Quantum Theory of Atoms in Molecules and the complexes stability has been performed.Supported by the University of Jaén (Plan de Apoyo a la Investigación, al Desarrollo Tecnológico y a la Innovación), Junta de Andalucía (PAIDI groups FQM195, FQM273 and FQM337) and the State Secretariat for Research, Development and Innovation of Spanish Ministry of Economy and Competitivity (Project “Red de Excelencia MetalBio”, CTQ2015-71211-REDT)

    Specific interaction of methionine adenosyltransferase with free radicals

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    Although free radicals have been traditionally implicated in cell injury, and associated to pathophysiological processes, recent data implicate them in cell signaling events. Free radicals are naturally occurring oxygen-,nitrogen-and sulfur-derived species with an unpaired electron, such as superoxide, hydroxyl radical or nitric oxide. In order to assess the role of free radicals in cell signaling, we have studies the modulator effect of oxygen and nitrogen active species on liver methionine adenosyltransferase (MAT), a key metabolic enzyme. The presence of 10 cysteine residues per subunit, makes liver MAT a sensitive target for oxidation/nitrosylation. Here we show that purified MAT from rat liver is nitrosylated and oxidized in vitro. Incubation with H202 or the NO donor S-nitrosylated GSH (GSNO), diminish MAT activity in a dose-and time-dependent manner. Furthermore, the inactivation derived from both oxidation and nitrosylation, was reverted by GSH. MAT inactivation originates on the specific and covalent modification of the sulphydryl group of cysteine residue 121. We also studied how free radicals modulate MAT activity in vivo. It was previously shown that MAT activity is strongly dependent on cellular GSH levels. Generation of oxygen and nitrogen active species in rats by injection of LPS, induced a decrease of liver MAT activity. This effect might derive from nitrosylation and/or oxidation of the enzyme. Modulation of liver MAT by NO is further supported by the inactivation of this enzyme observed in experimental models in which NO is produced; such as the administration of NO donors to rats and in hepatocytes cultured in hypoxia, a condition that induces the expression of the inducible nitric oxide synthase (iNOS). Oxidation also controls liver MAT activity in a cell environment as shown in CHO cells stably transfected with rat liver MAT cDNA upon addition of H2O2 to the culture medium. This effect depends upon the generation of the hydroxyl radical. On the basis of the metabolic implications of liver MAT, together with the structural features accounting for the sensitivity of this enzyme to active oxygen and nitrogen species, we propose that modulation of MAT by these agents could be a mechanism to regulate the consumption of ATP in the liver, and thus preserve cellular viability under different stress conditions

    La radiación solar: efectos en la salud y el medio ambiente

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    140 páginasEl incremento de cierto tipo de radiaciones ultravioletas procedentes del sol, perjudiciales para la salud y el medio ambiente es un tema de candente actualidad, a pesar de la aparente recuperación de la capa de ozono, filtro protector de la biosfera y de la calidad de vida de los seres que habitan el Planeta. La obra ha tratado de definir la situación actual de este gas a escala planetaria, analizando las causas físicas de su aparición y de su destrucción y las consecuencias que para el medio ambiente y la salud tiene el incremento de radiación ultravioleta

    Ultrashort pulsed Femtosecond UV laser for selective cleaning of significant Cretaceous flints

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    This work reports on studies aimed to evaluate the utilization of ultrashort 238 fs (fs) pulsed UV laser emission at 343 nm for eliminating colored crusts and surface deposits on significant Cretaceous flint surfaces, in an attempt to safeguard its aesthetic appearance and archaeological value. The results indicate that fs UV lasers may be an ideal, non-contact tool for selective surface cleaning of sensitive archaeological artefacts, since they enable contaminant desorption while avoiding photothermal damage

    Dihydrocapsiate does not increase energy expenditure nor fat oxidation during aerobic exercise in men with overweight/ obesity: a randomized, triple-blinded, placebo-controlled, crossover trial

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    Background: Prior evidence suggests that capsinoids ingestion may increase resting energy expenditure (EE) and fat oxidation (FATox), yet whether they can modulate those parameters during exercise conditions remains poorly understood. We hypothesized that dihydrocapsiate (DHC) ingestion would increase EE and specifically FATox during an acute bout of aerobic exercise at FATmax intensity (the intensity that elicits maximal fat oxidation during exercise [MFO]) in men with overweight/ obesity. Since FATmax and MFO during aerobic exercise appear to be indicators of metabolic flexibility, whether DHC has an impact on FATox in this type of population is of clinical interest. Methods: A total of 24 sedentary men (age = 40.2 ± 9.2 years-old; body mass index = 31.6 ± 4.5 kg/m2 [n = 11 overweight, n = 13 obese]) participated in this randomized, triple-blinded, placebocontrolled, crossover trial (registered under ClinicalTrials.gov Identifier no. NCT05156697). On the first day, participants underwent a submaximal exercise test on a cycle ergometer to determine their MFO and FATmax intensity during exercise. After 72 hours had elapsed, the participants returned on 2 further days (≥ 72 hours apart) and performed a 60 min steady-state exercise bout (i.e. cycling at their FATmax, constant intensity) after ingesting either 12 mg of DHC or placebo; these conditions were randomized. Respiratory gas exchange was monitored by indirect calorimetry. Serum marker concentrations (i.e. glucose, triglycerides, non-esterified fatty acids (NEFAs), skin temperature, thermal perception, heart rate, and perceived fatigue) were assessed. Results: There were no significant differences (P > 0.05) between DHC and placebo conditions in the EE and FATox during exercise. Similarly, no significant changes were observed in glucose, triglycerides, or NEFAs serum levels, neither in the skin temperature nor thermal perception across conditions. Heart rate and perceived fatigue did not differ between conditions. Conclusions: DHC supplementation does not affect energy metabolism during exercise in men with overweight/obesity.Spanish Junta de Andalucia via Consejeria de Conocimiento, Investigacion y Universidades, Proyectos I+D+i del Programa Operativo del Fondo Europeo de Desarrollo Regional (FEDER 2018) B.CTS.377.UGR18Spanish Government PTA 12264-I FPU16/02828 FPU16/0515

    Impaired Mitophagy and Protein Acetylation Levels in Fibroblasts from Parkinson's Disease Patients

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    Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder. While most PD cases are idiopathic, the known genetic causes of PD are useful to understand common disease mechanisms. Recent data suggests that autophagy is regulated by protein acetylation mediated by histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities. The changes in histone acetylation reported to be involved in PD pathogenesis have prompted this investigation of protein acetylation and HAT and HDAC activities in both idiopathic PD and G2019S leucine-rich repeat kinase 2 (LRRK2) cell cultures. Fibroblasts from PD patients (with or without the G2019S LRRK2 mutation) and control subjects were used to assess the different phenotypes between idiopathic and genetic PD. G2019S LRRK2 mutation displays increased mitophagy due to the activation of class III HDACs whereas idiopathic PD exhibits downregulation of clearance of defective mitochondria. This reduction of mitophagy is accompanied by more reactive oxygen species (ROS). In parallel, the acetylation protein levels of idiopathic and genetic individuals are different due to an upregulation in class I and II HDACs. Despite this upregulation, the total HDAC activity is decreased in idiopathic PD and the total HAT activity does not significantly vary. Mitophagy upregulation is beneficial for reducing the ROS-induced harm in genetic PD. The defective mitophagy in idiopathic PD is inherent to the decrease in class III HDACs. Thus, there is an imbalance between total HATs and HDACs activities in idiopathic PD, which increases cell death. The inhibition of HATs in idiopathic PD cells displays a cytoprotective effect
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