The radial abundance gradient of oxygen towards the Galactic anticentre

We present deep optical spectroscopy of eight HII regions located in the anticentre of the Milky Way. The spectra were obtained at the 10.4m GTC and 8.2m VLT. We determined Te([NII]) for all objects and Te([OIII]) for six of them. We also included in our analysis an additional sample of 13 inner-disc Galactic Hii regions from the literature that have excellent T_e determinations. We adopted the same methodology and atomic dataset to determine the physical conditions and ionic abundances for both samples. We also detected the CII and OII optical recombination lines in Sh 2-100, which enables determination of the abundance discrepancy factor for this object. We found that the slopes of the radial oxygen gradients defined by the HII regions from R_25 (= 11.5 kpc) to 17 kpc and those within R_25 are similar within the uncertainties, indicating the absence of flattening in the radial oxygen gradient in the outer Milky Way. In general, we found that the scatter of the O/H ratios of Hii regions is not substantially larger than the observational uncertainties. The largest possible local inhomogeneities of the oxygen abundances are of the order of 0.1 dex. We also found positive radial gradients in Te([O III]) and Te([N II]) across the Galactic disc. The shapes of these temperature gradients are similar and also consistent with the absence of flattening of the metallicity distribution in the outer Galactic disc.Comment: 20 pages, 11 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Societ

Molecular cell cycle mechanisms of human prostate crcinoma insensitivity to TGF-β?

TGF-β is a potent growth inhibitor of epithelial cells. However, many transformed cells have lost their sensitivity to this growth inhibitory effect. The molecular mechanism of such insensitivity is not yet understood. Here, we have studied the TGF-β1 effect on normal human prostate and carcinoma cells. Our results showed that normal cells were sensitive to growth inhibition, whereas tumor cells were not or only minimally inhibited regardless of the concentration of TGF-β1 (20 to 80 pM) or time of exposure (1-5 days). P21WAF1/Cip1/Sdi1 and p15INK4B but not p27K1P1 were detectable by Western blotting in normal and tumor cells. TGF-β1 treatment increased the association of p21WAF1/Cip1/Sdi1 with the Cdk2/cyclin E complex in both normal and prostate tumor cells. However, there was no increase in the association of p15INK4B nor p27K1P1 with the Cdk/cyclin complexes. In normal cells, the increase in the association of p21WAF1/Cip1/Sdi1 with the Cdk2/cyclin E complex resulted in inhibition of the Cdk2 activity. In contrast, although there was an increase in the association of p21WAF1/Cip1/Sdi1 with the Cdk2/cyclin E complex in tumor cells, there was no inhibition of the Cdk2 activity. These results indicate that a lack of inhibition of the Cdk2 activity correlates with the insensitivity to TGF-β1 in prostate tumor cells

Crenças sobre a avaliação e retenção escolar nos professores portugueses

The present research aims to understand which conceptions and beliefs Portuguese teachers have about assessment in compulsory school, and whether if their beliefs are in line with the guidelines on national education policy. Moreover, it aims to understand why Portuguese teachers use grade repetition as a common resource when it is not scientifically recommended. To do so, a focus group was conducted, and a survey carried out with a sample of Portuguese teachers’ population, with a 95% confidence level and a margin of error of 2.3%. Those procedures led to the conclusion that Portuguese teachers have personal beliefs towards assessment and grade repetition that have an impact on their practice and succeed in superimposing themselves on national educational policies and scientific recommendations.info:eu-repo/semantics/publishedVersio

Beam hardening artifact reduction using dual energy computed tomography: implications for myocardial perfusion studies

Background: Myocardial perfusion computed tomography (CTP) using conventional single energy (SE) imaging is influenced by the presence of beam hardening artifacts (BHA), occasionally resembling perfusion defects and commonly observed at the left ventricular posterobasal wall (PB). We therefore sought to explore the ability of dual energy (DE) CTP to attenuate the presence of BHA. Methods: Consecutive patients without history of coronary artery disease who were referred for computed tomography coronary angiography due to atypical chest pain and a normal stress-rest SPECT and had absence or mild coronary atherosclerosis constituted the study population. The study group was acquired using DE and the control group using SE imaging. Results: Demographical characteristics were similar between groups, as well as the heart rate and the effective radiation dose. Myocardial signal density (SD) levels were evaluated in 280 basal segments among the DE group (140 PB segments for each energy level from 40 keV to 100 keV; and 140 reference segments), and in 40 basal segments (at the same locations) among the SE group. Among the DE group, myocardial SD levels and myocardial SD ratio evaluated at the reference segment were higher at low energy levels, with significantly lower SD levels at increasing energy levels. Myocardial signal-to-noise ratio was not significantly influenced by the energy level applied, although 70 keV was identified as the energy level with the best overall signal-to-noise ratio. Significant differences were identified between the PB segment and the reference segment among the lower energy levels, whereas at ≥ 70 keV myocardial SD levels were similar. Compared to DE reconstructions at the best energy level (70 keV), SE acquisitions showed no significant differences overall regarding myocardial SD levels among the reference segments. Conclusions: Beam hardening artifacts that influence the assessment of myocardial perfusion can be attenuated using DE at 70 keV or higher.Fil: Rodriguez Granillo, Gaston Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentina. Diagnóstico Maipú; ArgentinaFil: Carrascosa, Patricia. Diagnóstico Maipú; ArgentinaFil: Cipriano, Silvia. Diagnóstico Maipú; ArgentinaFil: De Zan, Macarena. Diagnóstico Maipú; ArgentinaFil: Deviggiano, Alejandro. Diagnóstico Maipú; ArgentinaFil: Capunay, Carlos. Diagnóstico Maipú; ArgentinaFil: Cury, Ricardo C.. Miami Cardiac and Vascular Institute and Baptist Health; Estados Unido

Induced liver injury after high-dose methylprednisolone in a patient with multiple sclerosis

A 33-year-old woman with multiple sclerosis, medicated with high doses of methylprednisolone, cyclophosphamide and glatiramer acetate, was referred to our department due to acute liver injury. The laboratory investigation was normal except for weakly positive antinuclear antibodies. Cyclophosphamide and glatiramer acetate were suspended, and intravenous immunoglobulin with maintenance of high doses of methylprednisolone was initiated. The patient developed another episode of acute hepatitis so the immunoglobulin was stopped. After that, she had three more episodes of elevation of liver enzymes with no hepatic insufficiency while medicated only with high doses of methylprednisolone. At this time, liver biopsy showed focal centrilobubar hepatocyte necrosis with minimal interface hepatitis. After the high doses of methylprednisolone were suspended, the patient remained asymptomatic, with normal hepatic enzymes. This case emphasises that, although rare, induced liver injury after high doses of methylprednisolone can occur.info:eu-repo/semantics/publishedVersio