2,359 research outputs found

    A ringed pole-on outflow from DO Tauri revealed by ALMA

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    We present new ALMA Band 6 observations including the CO (2-1) line and 1.3 mmcontinuum emission from the surroundings of the young stellar object DO Tauri. TheALMA CO molecular data show three different series of rings at different radial ve-locities. These rings have radii around 220 au and 800 au. We make individual fits tothe rings and note that their centers are aligned with DO Tauri and its optical high-velocity jet. In addition, we notice that the velocity of these structures increases withthe separation from the young star. We discuss the data under the hypothesis that therings represent velocity cuts through three outflowing shells that are possibly drivenby a wide-angle wind, dragging the environment material along a direction close to theline of sight (i= 19◦). We estimate the dynamical ages, the mass, the momentum andthe energy of each individual outflow shell and those of the whole outflow. The resultsare in agreement with those found in outflows from Class II sources. We make a roughestimate for the size of the jet/wind launching region, which needs to be of.15 au.We report the physical characteristics of DO Tauri?s disk continuum emission (almostface-on and with a projected major axis in the north-south direction) and its velocitygradient orientation (north-south), indicative of disk rotation for a 1-2 Mcentral star.Finally we show an HST [SII] image of the optical jet and report a measurement of itsorientation in the plane of the sky.Fil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Zapata Gonzalez, Luis Alberto. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Rodríguez, Luis F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Guzman, Andrés E.. National Astronomical Observatory Of Japan; JapónFil: López, Rosario. Universidad Autónoma de Barcelona. Facultad de Física. Departamento Astronomía y Meteorología; Españ

    Fibrosis in hypertensive heart disease: role of the renin-angiotensin-aldosterone system

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    Structural homogeneity of cardiac tissue is governed by mechanical and humoral factors that regulate cell growth, apoptosis, phenotype, and extracellular matrix turnover. ANGII has endocrine, autocrine, and paracrine properties that influence the behavior of cardiac cells and matrix by AT1 receptor binding. Various paradigms have been suggested, including ANGII-mediated up-regulation of collagen types I and III formation and deposition in cardiac conditions, such as HHD. A growing body of evidence, however, deals with the potential role of aldosterone, either local or systemic, in inducing cardiac fibrosis. Aldosterone might also mediate the profibrotic actions of ANGII. To reduce the risk of heart failure that accompanies HHD, its adverse structural remodeling (eg, myocardial hypertrophy and fibrosis) must be targeted for pharmacologic intervention. Cardioprotective agents must reverse not only the exaggerated growth of cardiac cells, but also regress existing abnormalities in fibrillar collagen. Available experimental and clinical data suggest that agents interfering with ACE, the AT1 receptor, or the mineralocorticoid receptor may provide such a cardioprotective effect

    Myocardial fibrosis in arterial hypertension

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    It is now accepted that, in addition to left ventricular hypertrophy, hypertensive heart disease is characterized by alterations in myocardial structure, leading to loss of tissue homogeneity and pathological remodelling. It is time to recognize that, in hypertensive heart disease, it is not only the quantity but also the quality of the myocardium that is responsible for adverse cardiovascular events. The data reviewed here indicate that, in patients with hypertensive heart disease, myocardial fibrosis predisposes to an enhanced risk for diastolic and/or systolic ventricular dysfunction, symptomatic heart failure, ischaemic heart disease and arrhythmias

    Effect of Physicians' Attitudes and Knowledge on the Quality of Antibiotic Prescription: A Cohort Study

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    Resistance increases with the use and abuse of antibiotics. Since physicians are primarily responsible for the decision to use antibiotics, ascertaining the attitudes and knowledge that underlie their prescribing habits is thus a prerequisite for improving prescription. Three-year follow-up cohort study (2008-2010) targeting primary-care physicians (n = 2100) in Galicia, a region in NW Spain. We used data obtained from a postal survey to assess knowledge and attitudes. A physician was deemed to have demonstrated Appropriate Quality Prescription of Antibiotics (dependent variable) in any case where half or more of the indicators proposed by the European Surveillance of Antimicrobial Consumption had values that were better than the reference values for Spain. The mail-questionnaire response rate was 68·0% (1428/2100). The adjusted increase in the interquartile OR of displaying good prescribing of antibiotics for each attitude was: 205% for fear ("When in doubt, it is better to ensure that a patient is cured of an infection by using a broad-spectrum antibiotic"; 95%CI: 125% to 321%); 119% for better knowledge ("Amoxicillin is useful for resolving most respiratory infections in primary care"; 95%CI: 67% to 193%); and 21% for complacency with patients' demands ("Antibiotics are often prescribed due to patients' demands"; 95%CI: 0% to 45%). Due to the fact that physicians' knowledge and attitudes are potentially modifiable, the implementation of purpose-designed educational interventions based on the attitudes identified may well serve to improve antibiotic prescription

    Influence of adhesive systems on microtensile bond strength of resin-based endodontic sealers to the root dentin

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    Objective: The aim of this study was to determine the microtensile bond strength to root dentin of AH PlusTM and EndoREZ® with Clearfil Liner Bond 2V and Optibond SoloTM Plus adhesive systems. Study Design: The coronal and middle thirds of six single rooted bovine teeth was split longitudinally in a mesio- distal direction. The two halves were joined with AH Plus or EndoREZ, with and without the use of Clearfil Li - ner Bond 2V and Optibond SoloTM Plus adhesive systems. Build-ups were vertically sectioned into quadrangular (?1mmx1mm) compound bars and subjected to tensile tests at a constant crosshead speed (1 mm/min) until debon - ding. Results: Optibond ® Solo PlusTM in combination with AH PlusTM and EndoREZ ® showed the highest mean micro - tensile bond strength values, in both coronal and middle thirds. The lowest results were seen in the groups where no dentine adhesive was applied, and in those where the self-etching adhesive Clearfil Liner Bond 2V was used. Conclusion: The microtensile bond strength to root dentin of AH PlusTM and EndoREZ may be increased with the use of a total-etch adhesive

    Tuning the electronic and magnetic properties of 2D g-GaN by H adsorption: An ab-initio study

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    We have theoretically studied the structural, electronic and magnetic properties of the hydrogen adsorption on a honeycomb gallium-nitride two-dimensional monolayer (2D g-GaN). Results indicate that the band gap energy can be systematically tuned by the hydrogen coverage on the 2D g-GaN in the diluted limit. In addition, a total magnetic moment can be induced in the 2D g-GaN by hydrogen adsorption due to s-p interaction and band structure effects. Although hydrogen adsorption on top of nitrogen atoms shows the most stable energy in the 2D g-GaN, the most stable ferromagnetism -with a nonzero magnetic moment-is obtained when hydrogen is adsorbed on top of Ga atoms. These results indicate that H adatoms on the 2D g-GaN systems could be a potential candidate for future spintronic applications

    Respuestas del miocardio al estrés biomecánico

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    El estrés biomecánico del miocardio hace referencia a la situación que se genera cuando, debido a la hipertensión, la hipoxia u otras formas de daño miocárdico, están aumentadas las demandas de trabajo cardíaco y/o se ha perdido miocardio funcionante. Como consecuencia del estrés biomecánico se producen diversas respuestas que afectan a todas las células miocárdicas, en particular a los cardiomiocitos. El resultado final de las mismas son distintas modificaciones fenotípicas que inicialmente son compensadoras (p. ej., hipertrofia), pero que si persiste el estrés pueden mediar la transición de la hipertrofia a la insuficiencia cardíaca (p. ej., apoptosis y fibrosis). Esta revisión se centra en la descripción de las distintas fases de las respuestas miocárdicas al estrés, así como en la consideración de los hallazgos más recientes sobre los mecanismos moleculares implicados en el desarrollo de insuficiencia cardíaca

    Association of increased plasma cardiotrophin-1 with inappropriate left ventricular mass in essential hypertension

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    Inappropriate left ventricular mass is present when the value of left ventricular mass exceeds individual needs to compensate hemodynamic load imposed by increased blood pressure. The goal of this study was to investigate whether plasma concentration of cardiotrophin-1, a cytokine that induces exaggerated hypertrophy in cardiomyocytes with hypertensive phenotype, is related to inappropriate left ventricular mass in patients with essential hypertension. The study was performed in 118 patients with never-treated hypertension and without prevalent cardiac disease. The left ventricular mass prediction from stroke work (systolic blood pressurexDoppler stroke volume), sex, and height (in meters(2.7)) was derived. An observed left ventricular mass/predicted left ventricular mass value >128% defined inappropriate left ventricular mass. Plasma cardiotrophin-1 was measured by an enzyme-linked immunosorbent assay. The studies were repeated in a group of 45 patients after 1 year of antihypertensive treatment. At baseline 67 and 51 patients presented with appropriate and inappropriate left ventricular mass, respectively. Plasma cardiotrophin-1 was higher (P<0.001) in patients with inappropriate mass than in patients with appropriate mass and normotensive controls. A direct correlation was found between cardiotrophin-1 and observed left ventricular mass/predicted left ventricular mass ratio (r=0.330, P<0.001) in all hypertensive patients. After treatment, plasma cardiotrophin-1 decreased and increased in patients in which inappropriate left ventricular mass regressed and persisted, respectively, despite a similar reduction of blood pressure in the 2 subgroups of patients. Albeit descriptive in nature, these results suggest the hypothesis that an excess of cardiotrophin-1 may contribute to inappropriate left ventricular growth in hypertensive patients
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