119 research outputs found

    First Results from the Herschel and ALMA Spectroscopic Surveys of the SMC: The Relationship between [C ii ]-bright Gas and CO-bright Gas at Low Metallicity

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    The Small Magellanic Cloud (SMC) provides the only laboratory to study the structure of molecular gas at high resolution and low metallicity. We present results from the Herschel Spectroscopic Survey of the SMC (HS3), which mapped the key far-IR cooling lines [C ii], [O i], [N ii], and [O iii] in five star-forming regions, and new ALMA 7 m array maps of 12CO{}^{12}\mathrm{CO} and 13CO{}^{13}\mathrm{CO} (21)(2-1) with coverage overlapping four of the five HS3 regions. We detect [C ii] and [O i] throughout all of the regions mapped. The data allow us to compare the structure of the molecular clouds and surrounding photodissociation regions using 13CO{}^{13}\mathrm{CO}, 12CO{}^{12}\mathrm{CO}, [C ii], and [O i] emission at 10\lesssim 10^{\prime\prime} (<3\lt 3 pc) scales. We estimate AV{A}_{V} using far-IR thermal continuum emission from dust and find that the CO/[C ii] ratios reach the Milky Way value at high AV{A}_{V} in the centers of the clouds and fall to \sim 1/5\mbox{--}1/10\times the Milky Way value in the outskirts, indicating the presence of translucent molecular gas not traced by bright 12CO{}^{12}\mathrm{CO} emission. We estimate the amount of molecular gas traced by bright [C ii] emission at low AV{A}_{V} and bright 12CO{}^{12}\mathrm{CO} emission at high AV{A}_{V}. We find that most of the molecular gas is at low AV{A}_{V} and traced by bright [C ii] emission, but that faint 12CO{}^{12}\mathrm{CO} emission appears to extend to where we estimate that the H2{{\rm{H}}}_{2}-to-H i transition occurs. By converting our H2{{\rm{H}}}_{2} gas estimates to a CO-to-H2{{\rm{H}}}_{2} conversion factor (X CO), we show that X CO is primarily a function of AV{A}_{V}, consistent with simulations and models of low-metallicity molecular clouds

    Sub-microscopic malaria cases and mixed malaria infection in a remote area of high malaria endemicity in Rattanakiri province, Cambodia: implication for malaria elimination

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    BACKGROUND: Malaria microscopy and rapid diagnostic tests are insensitive for very low-density parasitaemia. This insensitivity may lead to missed asymptomatic sub-microscopic parasitaemia, a potential reservoir for infection. Similarly, mixed infections and interactions between Plasmodium species may be missed. The objectives were first to develop a rapid and sensitive PCR-based diagnostic method to detect low parasitaemia and mixed infections, and then to investigate the epidemiological importance of sub-microscopic and mixed infections in Rattanakiri Province, Cambodia. METHODS: A new malaria diagnostic method, using restriction fragment length polymorphism analysis of the cytochrome b genes of the four human Plasmodium species and denaturing high performance liquid chromatography, has been developed. The results of this RFLP-dHPLC method have been compared to 1) traditional nested PCR amplification of the 18S rRNA gene, 2) sequencing of the amplified fragments of the cytochrome b gene and 3) microscopy. Blood spots on filter paper and Giemsa-stained blood thick smears collected in 2001 from 1,356 inhabitants of eight villages of Rattanakiri Province have been analysed by the RFLP-dHPLC method and microscopy to assess the prevalence of sub-microscopic and mixed infections. RESULTS: The sensitivity and specificity of the new RFLP-dHPLC was similar to that of the other molecular methods. The RFLP-dHPLC method was more sensitive and specific than microscopy, particularly for detecting low-level parasitaemia and mixed infections. In Rattanakiri Province, the prevalences of Plasmodium falciparum and Plasmodium vivax were approximately two-fold and three-fold higher, respectively, by RFLP-dHPLC (59% and 15%, respectively) than by microscopy (28% and 5%, respectively). In addition, Plasmodium ovale and Plasmodium malariae were never detected by microscopy, while they were detected by RFLP-dHPLC, in 11.2% and 1.3% of the blood samples, respectively. Moreover, the proportion of mixed infections detected by RFLP-dHPLC was higher (23%) than with microscopy (8%). CONCLUSIONS: The rapid and sensitive molecular diagnosis method developed here could be considered for mass screening and ACT treatment of inhabitants of low-endemicity areas of Southeast Asia

    XPD codon 312 and 751 polymorphisms, and AFB1 exposure, and hepatocellular carcinoma risk

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    <p>Abstract</p> <p>Background</p> <p>Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of hepatocellular carcinoma (HCC) related to the exposure of aflatoxin B1 (AFB1). In this study, we have focused on the polymorphisms of xeroderma pigmentosum complementation group D (XPD) codon 312 and 751 (namely Asp312Asn and Lys751Gln), involved in nucleotide excision repair.</p> <p>Methods</p> <p>We conducted a case-control study including 618 HCC cases and 712 controls to evaluate the associations between these two polymorphisms and HCC risk for Guangxi population by means of TaqMan-PCR and PCR-RFLP analysis.</p> <p>Results</p> <p>We found that individuals featuring the XPD genotypes with codon 751 Gln alleles (namely XPD-LG or XPD-GG) were related to an elevated risk of HCC compared to those with the homozygote of XPD codon 751 Lys alleles [namely XPD-LL, adjusted odds ratios (ORs) were 1.75 and 2.47; 95% confidence interval (CIs) were 1.30-2.37 and 1.62-3.76, respectively]. A gender-specific role was evident that showed an higher risk for women (adjusted OR was 8.58 for XPD-GG) than for men (adjusted OR = 2.90 for XPD-GG). Interestingly, the interactive effects of this polymorphism and AFB1-exposure information showed the codon 751 Gln alleles increase the risk of HCC for individuals facing longer exposure years (<it>P</it><sub>interaction </sub>= 0.011, OR = 0.85). For example, long-exposure-years (> 48 years) individuals who carried XDP-GG had an adjusted OR of 470.25, whereas long-exposure-years people with XDP-LL were at lower risk (adjusted OR = 149.12). However, we did not find that XPD codon 312 polymorphism was significantly associated with HCC risk.</p> <p>Conclusion</p> <p>These findings suggest that XPD Lys751Gln polymorphism is an important modulator of AFB1 related-HCC development in Guangxi population.</p

    Dust and gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. I. Dust properties and insights into the origin of the submillimeter excess emission

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    The dust properties in the Large and Small Magellanic clouds (LMC/SMC) are studied using the HERITAGE Herschel Key Project photometric data in five bands from 100 to 500 μm. Three simple models of dust emission were fit to the observations: a single temperature blackbody modified by a power-law emissivity (SMBB), a single temperature blackbody modified by a broken power-law emissivity (BEMBB), and two blackbodies with different temperatures, both modified by the same power-law emissivity (TTMBB). Using these models, we investigate the origin of the submillimeter excess, defined as the submillimeter emission above that expected from SMBB models fit to observations <200 μm. We find that the BEMBB model produces the lowest fit residuals with pixel-averaged 500 μm submillimeter excesses of 27% and 43% for the LMC and SMC, respectively. Adopting gas masses from previous works, the gas-to-dust ratios calculated from our fitting results show that the TTMBB fits require significantly more dust than are available even if all the metals present in the interstellar medium (ISM) were condensed into dust. This indicates that the submillimeter excess is more likely to be due to emissivity variations than a second population of colder dust. We derive integrated dust masses of (7.3 ± 1.7) × 105 and (8.3 ± 2.1) × 104 M ☉ for the LMC and SMC, respectively. We find significant correlations between the submillimeter excess and other dust properties; further work is needed to determine the relative contributions of fitting noise and ISM physics to the correlations

    Improved Cardiopulmonary Resuscitation Performance With CODE ACES 2

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    Acurácia dos achados mamográficos do câncer de mama: correlação da classificação BI-RADS e achados histológicos Accuracy of mammographic findings in breast cancer: correlation between BI-RADS classification and histological findings

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    OBJETIVO: A proposta deste estudo foi avaliar a acurácia da classificação BI-RADS® na mamografia. Os pontos secundários foram descrever a frequência de apresentação dos diferentes achados mamográficos e avaliar a concordância entre observadores. MATERIAIS E MÉTODOS: Os exames de 115 pacientes, encaminhados para core biopsy, foram reavaliados independentemente por dois médicos especialistas, cegados, utilizando a recomendação do BI-RADS. Posteriormente, os exames foram comparados com a histologia. A acurácia da classificação BI-RADS na mamografia foi avaliada. A concordância entre os médicos foi calculada pela estatística kappa (&#954;) de Cohen e as diferenças nos grupos de comparação foram analisadas com teste qui-quadrado. RESULTADOS: Esta pesquisa demonstrou que a acurácia mamográfica oscilou de 75% a 62% na diferenciação entre lesões benignas de malignas com o uso do BI-RADS. Houve importante concordância na descrição das margens dos nódulos (&#954;= 0,66). Baixa concordância foi identificada na descrição dos contornos (formas) dos nódulos (&#954;= 0,40) e na descrição das calcificações, tanto em relação à sua distribuição (&#954;= 0,24) como também em relação à morfologia (&#954;= 0,36). CONCLUSÃO: O presente estudo demonstrou que o método é acurado na diferenciação de lesões benignas de malignas. A concordância foi fraca na análise das calcificações quanto a morfologia e distribuição, no entanto, identificou-se elevação progressiva dos valores preditivos positivos nas subcategorias 4.<br>OBJECTIVE: The present study was aimed at evaluating the BI-RADS® classification accuracy in mammography. Additionally, the frequency of different findings was described and the interobserver agreement was evaluated. MATERIALS AND METHODS: Mammographic images of 115 patients were independently and blindly reviewed by two specialists in compliance with BI-RADS recommendations, and later compared with histological data. The BI-RADS accuracy in mammography was evaluated. The interobserver agreement was analyzed with the Cohen's kappa (&#954;) test, and the differences between groups were evaluated with the chi-squared test. RESULTS: The present study demonstrated that the mammographic accuracy ranged from 75% to 62% in the differentiation between benign and malignant lesions with the utilization of the BI-RADS classification. Statistically significant interobserver agreement was observed in the description of masses margins (&#954;= 0.66). A low agreement rate was identified in the description of masses borders (shape) (&#954;= 0.40) and calcifications, both in relation to their distribution (&#954;= 0.24) and morphology (&#954;= 0.36). CONCLUSION: The present study demonstrated the BI-RADS accuracy in the differentiation between benign and malignant lesions. The interobserver agreement was poor in the analysis of calcifications morphology and distribution, but a progressive increase in the positive predictive values was observed in the subcategory 4

    Inflammatory changes in ruptured canine cranial and human anterior cruciate ligaments

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    To compare expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K and histologic changes in canine cranial cruciate ligaments (CCLs) and human anterior cruciate ligaments (ACLs). Sections of cruciate ligaments from 15 dogs with ruptured CCLs, 8 aged dogs with intact CCLs, 14 human beings with ruptured ACLs, and 11 aged human beings with intact ACLs. The CCLs and ACLs were evaluated histologically, and cells containing TRAP and cathepsin K were identified histochemically and immunohistochemically, respectively. The proportion of ruptured CCLs that contained TRAP+ cells was significantly higher than the proportion of intact ACLs that did but similar to proportions of intact CCLs and ruptured ACLs that did. The proportion of ruptured CCLs that contained cathepsin K+ cells was significantly increased, compared with all other groups. Numbers of TRAP+ and cathepsin K+ cells were significantly increased in ruptured CCLs, compared with intact ACLs. The presence of TRAP+ cells was correlated with inflammatory changes, which were most prominent in ruptured CCLs. Results suggest that synovial macrophage-like cells that produce TRAP are an important feature of the inflammation associated with CCL rupture in dogs. Identification of TRAP and cathepsin K in intact CCLs and ACLs from aged dogs suggests that these enzymes have a functional role in cruciate ligament remodeling and repair. We hypothesize that recruitment and activation of TRAP+ macrophage-like cells into the stifle joint synovium and CCL epiligament are critical features of the inflammatory arthritis that promotes progressive degradation and eventual rupture of the CCL in dogs
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