259 research outputs found

    The structure of molecular clumps around high-mass young stellar objects

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    We have used the IRAM 30-m and FCRAO 14-m telescopes to observe the molecular clumps associated with 12 ultracompact (UC) HII regions in the J=6-5, 8-7 and 13-12 rotational transitions of methyl-acetylene (CH3C2H). Under the assumption of LTE and optically thin emission, we have derived temperature estimates ranging from 30 to 56 K. We estimate that the clumps have diameters of 0.2-1.6 pc, H_2 densities of 10^5-10^6 {cm^{-3}}, and masses of 10^2-2 10^4 M_\odot. We compare these values with those obtained by other authors from different molecular tracers and find that the H_2 density and the temperature inside the clumps vary respectively like n_{H_2} ~ R^{-2.6} and T ~ R^{-0.5}, with R distance from the centre. We also find that the virial masses of the clumps are ~3 times less than those derived from the CH3C2H column densities: we show that a plausible explanation is that magnetic fields play an important role to stabilise the clumps, which are on the verge of gravitational collapse. Finally, we show that the CH3C2H line width increases for decreasing distance from the clump centre: this effect is consistent with infall in the inner regions of the clumps. We conclude that the clumps around UC HII regions are likely to be transient (~10^(5) yr) entities, remnants of isothermal spheres currently undergoing gravitational collapse: the high mass accretion rates (~10^{-2} M_\odot yr^{-1}) lead to massive star formation at the centre of such clumps.Comment: 15 pages, 11 figures, A & A in pres

    The kinematics of molecular clumps surrounding hot cores in G29.96-0.02 and G31.41+0.31

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    We present high angular resolution interferometric observations of the 3 and 1.3mm continuum emission, and HCO+(1-0) and SiO(2-1)v=0 lines, obtained with the Owens Valley Radio Observatory millimeter-wave array, toward two hot cores (HCs) associated with two well known ultracompact (UC) HII regions: G29.96-0.02 and G31.41+0.31. These HCs are believed to host young forming massive stars which have been suggested to be surrounded by massive rotating accretion disks. The aim of these new observations is to study the structure and kinematics of the molecular clumps surrounding the HCs and nearby UCHII regions at moderately high angular resolution. Our observations reveal that the clumps within which the HCs and UCHII regions are embedded have a complex kinematical structure. The total mass of the clumps is estimated to be in the range 1000-3000 Msun, consistent with previous findings. Our observations also show compelling evidence that the clump in G29.96-0.02 is contracting onto the HC position, suggesting that the accretion process onto the massive young stellar object embedded in the HC is still ongoing. In these objects the kinematical structure that we observe is also compatible with the presence of a massive rotating disk within the HC, even though we cannot prove this suggestion with our data. The case of G31.41+0.31 is more complicated, and our data, although consistent with the presence of an inner disk and an infalling envelope around it, do not have the required spatial resolution to resolve the different structures.Comment: 13 pages, 15 figs, A&A in pres

    Nestin expression associates with poor prognosis and triple negative phenotype in locally advanced (T4) breast cancer

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    Nestin, an intermediate filament protein, has traditionally been noted for its importance as a neural stem cell marker. However, in recent years, expression of nestin has shown to be associated with general proliferation of progenitor cell populations within neoplasms. There is no reported study addressing nestin expression in T4 breast cancer patients. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of nestin in T4 breast cancer, in order to determine its association with clinical and pathological parameters as well as with patients' outcome. Nestin was detectable in tumoral cells and in endothelial cells of blood microvessels, and it is significantly expressed in triple-negative and in inflammatory breast cancer (IBC) subgroups of T4 breast tumours. The Kaplan-Meier analysis showed that the presence of nestin in tumoral cells significantly predicted poor prognosis at 5-years survival (P=0.02) and with borderline significance at 10-years of survival (P=0.05) in T4 breast cancer patients. On the basis of these observations, we speculate that nestin expression may characterize tumours with an aggressive clinical behavior, suggesting that the presence of nestin in tumoral cells and vessels may be considered an important factor that leads to a poor prognosis. Further studies are awaited to define the biological role of nestin in the etiology of these subgroups of breast cancers

    New insights on the antifungal activity of essential oil of Salvia desoleana Atzei et Picci, an endemic plant from folk medicine of Sardinia, Italy

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    757-760This work reports the results concerning the antifungal activity of the essential oil obtained from Salvia desoleana, an endemic plant from folk medicine of Sardinia Island, Italy. Chemical analysis of S. desoleana essential oil isolated by hydrodistillation was carried out by gas chromatography (GC-FID) and gas chromatography–mass spectrometry (GC-MS). The essential oil contains high amounts of oxygenated monoterpenes and sesquiterpene hydrocarbons, being linalyl acetate (21.0%), a-terpinyl acetate (17.3%), 1,8-cineole (6.7%), linalool (3.6%), sclareol (3.5%) and germacrene D (22.1%) the main compounds. The oil was more active against the yeast Cryptococcus neoformans and the dermatophyte Trichophyton rubrum with MIC values of 0.16 μL/mL and 0.32 μL/mL, respectively. The oil revealed an important inhibitory effect on the germ tube formation in C. albicans. It was able to achieve about 40% of inhibition of filamentation at concentrations as low as 0.08 µL/mL. These findings add significant information to the biological activity of the essential oil of S. desoleana, specifically to its antifungal properties, thus justifying and reinforcing the use of this plant in traditional medicine

    New insights on the antifungal activity of essential oil of Salvia desoleana Atzei et Picci, an endemic plant from folk medicine of Sardinia, Italy

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    This work reports the results concerning the antifungal activity of the essential oil obtained from Salvia desoleana, an endemic plant from folk medicine of Sardinia Island, Italy. Chemical analysis of S. desoleana essential oil isolated by hydrodistillation was carried out by gas chromatography (GC-FID) and gas chromatography–mass spectrometry (GC-MS). The essential oil contains high amounts of oxygenated monoterpenes and sesquiterpene hydrocarbons, being linalyl acetate (21.0%), a-terpinyl acetate (17.3%), 1,8-cineole (6.7%), linalool (3.6%), sclareol (3.5%) and germacrene D (22.1%) the main compounds. The oil was more active against the yeast Cryptococcus neoformans and the dermatophyte Trichophyton rubrum with MIC values of 0.16 μL/mL and 0.32 μL/mL, respectively. The oil revealed an important inhibitory effect on the germ tube formation in C. albicans. It was able to achieve about 40% of inhibition of filamentation at concentrations as low as 0.08 µL/mL. These findings add significant information to the biological activity of the essential oil of S. desoleana, specifically to its antifungal properties, thus justifying and reinforcing the use of this plant in traditional medicine

    Prognostic prediction of the immunohistochemical expression of p16 and p53 in cutaneous melanoma: a comparison of two populations from different geographical regions

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    p16INK4a and p53 are tumor-suppressor genes frequently altered in various malignancies, including cutaneous melanoma. The purpose of the study was to establish the prognostic value of immunohistochemical expression of p16INK4a and p53 in sporadic cutaneous melanoma (CM) in two regions with a high-risk for melanoma in Italy and Ecuador. Immunohistochemical staining of p16 and p53 was performed in samples of primary CM from 82 patients with Stage I and II melanoma according to the American Joint Committee on Cancer (AJCC) staging system. Survival differences between categories of p16 or p53 expression were analyzed using the product-limit procedure (Kaplan-Meier method, log-rank test). Clinical variables (gender, age, tumor location, Clark’s level, thickness) were correlated with survival and p16 or p53 expression. p16 nuclear immunoreactivity was observed in 85% of Italian patients compared to 48.7% of Ecuadorians; a small number of cases showed p53 immunoreactivity in both populations. Only nuclear p16 expression exhibited a significant correlation with survival (Italians p=0.001, Ecuadorians p=0.017) but did not appear to correlate with any clinicopathological parameter. No significant difference was observed in survival with regard to p53 expression or cytoplasmic p16. Our results demonstrate that nuclear expression of p16 can be considered a molecular prognostic factor in patients with sporadic CM and indicate its importance as a clinical marker

    A VLT spectroscopic study of the ultracompact HII region G29.96-0.02

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    A high quality, medium-resolution K-band spectrum has been obtained of the ultracompact HII region G29.96-0.02 with the Very Large Telescope (VLT). The slit was positioned along the symmetry axis of the cometary shaped nebula. Besides the spectrum of the embedded ionizing O star, the long-slit observation revealed the rich emission-line spectrum produced by the ionized nebula with sub-arcsec spatial resolution. The nebular spectrum includes BrÎł\gamma, several helium emission lines and a molecular hydrogen line. A detailed analysis is presented of the variation in strength, velocity and width of the nebular emission lines along the slit. The results are consistent with previous observations, but the much better spatial resolution allows a critical evaluation of models explaining the cometary shape of the nebula. Our observations support neither the wind bow shock model nor the champagne flow model. The measured line ratios of the nebular hydrogen and helium lines are compared to predictions from case B recombination-line theory. The results indicate an electron temperature between 6400 and 7500 K, in good agreement with other determinations and the Galactocentric distance of 4.6 kpc. The He+^{+}/H+^{+} ratio is practically constant over the slit; we argue that He is singly ionized throughout the nebula. We review the various observational constraints on the effective temperature of the ionizing star and show that these are in agreement with its K-band spectral type of O5-O6V.Comment: 15 pages including 11 figures and 2 tables, LaTex, A&A style. Accepted for publication in A&

    Vegan-vegetarian low-protein supplemented diets in pregnant CKD patients: fifteen years of experience

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    Background: Pregnancy in women with advanced CKD becoming increasingly common. However, experience with low-protein diets in CKD patients in pregnancy is still limited. Aim of this study is to review the results obtained over the last 15 years with moderately restricted low-protein diets in pregnant CKD women (combining: CKD stages 3-5, proteinuria: nephrotic at any time, or > =1 g/24 at start or referral; nephrotic in previous pregnancy). CKD patients on unrestricted diets were employed for comparison. Methods: Study period: January, 2000 to September, 2015: 36 on-diet pregnancies (31 singleton deliveries, 3 twin deliveries, 1 pregnancy termination, 1 miscarriage); 47 controls (42 singleton deliveries, 5 miscarriages). The diet is basically vegan; since occasional milk and yoghurt are allowed, we defined it vegan-vegetarian; protein intake (0.6-0.8 g/Kg/day), keto-acid supplementation, protein-unrestricted meals (1-3/week) are prescribed according to CKD stage and nutritional status. Statistical analysis was performed as implemented on SPSS. Results: Patients and controls were similar (p: ns) at baseline with regard to age (33 vs 33.5), referral week (7 vs 9), kidney function (CKD 3-5: 48.4 % vs 64.3 %); prevalence of hypertension (51.6 % vs 40.5 %) and proteinuria >3 g/24 h (16.1 % vs 12.2 %). There were more diabetic nephropathies in on-diet patients (on diet: 31.0 % vs controls 5.3 %; p 0.007 (Fisher)) while lupus nephropathies were non-significantly higher in controls (on diet: 10.3 % vs controls 23.7 %; p 0.28 (Fisher)). The incidence of preterm delivery was similar (<37 weeks: on-diet singletons 77.4 %; controls: 71.4 %). The incidence of other adverse pregnancy related outcomes was non-significantly lower in on-diet patients (early preterm delivery: on diet: 32.3 % vs controls 35.7 %; birth-weight = <1.500 g: on diet: 9.7 % vs controls 23.8 %). None of the singletons in the on-diet series died, while two perinatal deaths occurred among the controls (p = 0.505). The incidence of small for gestational age (SGA <10th centile) and/or extremely preterm babies (<28th week) was significantly lower in singletons from on-diet mothers than in controls (on diet: 12.9 % vs controls: 33.3 %; p: 0.04 (Fisher)). Conclusion: Moderate protein restriction in the context of a vegan-vegetarian supplemented diet is confirmed as a safe option in the management of pregnant CKD patients

    Prevalence of human papillomavirus infection in women in Benin, West Africa

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    <p>Abstract</p> <p>Background</p> <p>Cervical cancer ranks as the first most frequent cancer among women in Benin. The major cause of cervical cancer now recognized is persistent infection of Human Papillomavirus (HPV). In Benin there is a lack of screening programs for prevention of cervical cancer and little information exists regarding HPV genotype distribution.</p> <p>Methods</p> <p>Cervical cells from 725 women were examined for the presence of viral DNA by means of a polymerase chain reaction (PCR) multiplex-based assay with the amplification of a fragment of L1 region and of E6/E7 region of the HPV genome, and of abnormal cytology by Papanicolaou method. The association between HPV status and Pap test reports was evaluated. Socio-demographic and reproductive characteristics were also related.</p> <p>Results</p> <p>A total of 18 different HPV types were identified, with a prevalence of 33.2% overall, and 52% and 26.7% among women with and without cervical lesions, respectively. Multiple HPV infections were observed in 40.2% of HPV-infected women. In the HPV-testing group, the odds ratio for the detection of abnormal cytology was 2.98 (95% CI, 1.83-4.84) for HPV positive in comparison to HPV negative women. High risk types were involved in 88% of infections, most notably HPV-59, HPV-35, HPV-16, HPV-18, HPV-58 and HPV-45. In multiple infections of women with cytological abnormalities HPV-45 predominated.</p> <p>Conclusions</p> <p>This study provides the first estimates of the prevalence of HPV and type-specific distribution among women from Benin and demonstrates that the epidemiology of HPV infection in Benin is different from that of other world regions. Specific area vaccinations may be needed to prevent cervical cancer and the other HPV-related diseases.</p

    Measurement of isotopic separation of argon with the prototype of the cryogenic distillation plant Aria for dark matter searches

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    The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26&nbsp;m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes: 36Ar , 38Ar , and 40Ar . We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019
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