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A study of the cathodoluminescence (CL) properties of imperial topaz from Ouro Preto region (Minas Gerais state, Brazil) and its relation with trace-element composition was conducted, using scanning electron microscope cathodoluminescence (SEM-CL), optical microscope cathodoluminescence (OM-CL), cathodoluminescence-spectrometry (CL-spectrometry), electron microprobe analysis (EMPA), laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) and Raman spectrometry. Each analytical technique allowed characterization of the imperial topaz fingerprint. SEM-CL panchromatic images show different crystal growth and resorption events in imperial topaz crystals. Colour CL images indicate only blue to violet emissions. The CL-spectra indicate a broad emission band with low intensity peak at ∼417 nm and a broad emission band with high intensity and major peaks at 685, 698, 711 and 733 nm. The EMPA indicates high OH content, in which the OH/(OH + F) ratio ranges between 0.35-0.43 (0.72 ≤ OH ≤ 0.86 apfu). High Cu and Zn concentrations (LA-ICP-MS) were measured in the high luminescence areas of SEM-CL images, suggesting both elements as CL-activators in imperial topaz. Raman and CL-spectra indicate high Cr concentrations, corroborated by EMPA and LA-ICP-MS results. The high Cr caused strong luminescence intensities that enabled their superimposition over the OH stretching mode (∼3650 cm-1) of topaz in all Raman spectra. Among trace elements, the concentrations of Ti, V, Cr, Mn, Fe, Cu, Zn, Ga and Ge provide the fingerprint of imperial topaz.

“Imperial” topaz is a gemstone variety that occurs in the Ouro Preto region (Minas Gerais state, Brazil). Polygonal sectors within the core and rims of topaz crystals, were optically observed but without consensual explanations about them. With the aid of optical microscopy, scanning electron microscopy-cathodoluminescence (SEM-CL), backscattered electrons (BSE) imaging, electron probe micro-analyser (EPMA) chemical analyses and electron backscatter diffraction (EBSD) maps, the present study intended to demonstrate the distinct crystallographic orientations within “imperial” topaz and relate the polygonal sectors with the compositional data. Cross-polarised transmitted-light photomicrographs show a well delimited and optically heterogeneous central rhombic area at (21 l) in the cores, and quadrant-like and alternated extinction areas at (200, (010) and (110) in the rims. Scanning electron microscopy-cathodoluminescence images show a central rhombic area heterogeneously luminescent in the core, and dark and homogeneous rims. Grey and completely homogeneous BSE images and EPMA results corroborate constant and homogeneous major composition of “imperial” topaz. Electron backscatter diffraction maps collected in the rim region show different areas and microstructural features instead of a uniform microstructure. The respective pole figures of orthorhombic system yielded multiple (001) poles disoriented in higher than 15° from each other. These results display numerous c-axes, suggesting distinct crystallographic orientations, and no reduction in the orthorhombic symmetry. Therefore, the presumed monocrystal of “imperial” topaz actually is a polycrystal.

Tourmaline is a valuable forensic mineral that contains a wide range of elemental components capable of reconstructing its geologic evolution. In this study, we developed detailed petrographic and geochemical research on tourmaline-bearing rocks and tourmalinites found surrounding the ca. 3.30 Ga rhyolite of the Gavião Block, northern São Francisco Craton. Two distinct types of mineral assemblages in the tourmaline-bearing rocks are recognized based on the presence of sulfides, oxide minerals, and carbonaceous matter. Along with these tourmaline-bearing rocks, tourmalinite samples are found. The mineral chemistry of tourmalines from the two types of tourmaline-bearing rocks reveals mainly schorl-dravite as tourmaline from a mineral assemblage containing quartz, tourmaline, pyrite, and hematite, and a diverse composition ranging from schorl-dravite, feruvite-uvite, and schorl-feruvite solid solutions for tourmalines present in the mineral assemblage that contains quartz, pyrite, and carbonaceous matter. The tourmaline composition is essentially foitite-schorl in tourmalinite samples. Most of the metasedimentary rocks studied have felsic and mafic source compositions. The interaction of hydrothermal fluid was crucial for the formation of sulfide and tourmaline minerals. However, distinct tourmaline origins are recognized in tourmaline-rich rocks, pointing out the relevance of sedimentary and metamorphic processes.

The Integrated Program of Leprosy Control was initiated in the municipality of Buriticupu, Maranhão, Brazil, an area considered hyperendemic for leprosy in 2003. It aims at assessing the clinical and epidemiological characteristics of the disease to reduce the detection rate of new cases until 2015. Here, we present the evolution of the indicators of leprosy within the period from 2003 to 2015. We conducted a descriptive analytical study based on the active search for and voluntary referral of cases of leprosy. The detection rate of new cases was analyzed over time. We included individuals diagnosed with leprosy between January 2003 and December 2015. The association between categorical variables was assessed using the chi-square test of independence, considering a level of significance of 5%. When the association was significant, the detection rate (with a confidence interval of 95%) was calculated. Overall, 879 new leprosy cases were detected; the majority of the affected individuals were men (65.9%). Multibacillary leprosy was the most common type of the disease, according to the operational classification (55.5%); it showed the strongest association with an age ≥60 years. We also detected an association between the male sex and both, lepromatous and multibacillary leprosy. The detection rate reduced from 211.09/100,000 population in 2003 to 50.26/100,000 population in 2015. We found an improvement in leprosy control, with a reduction in the detection rate and the absolute number of cases. Strengthening of disease control measures should be prioritized to eliminate leprosy as a public health concern in this municipality.

Accessions of Lycopersicon chilense, L. peruvianum, L.hirsutum and sixteen L. esculentum genotypes were evaluated undergreenhouse conditions for resistance to a whitefly-transmitted geminivirusisolate from Brasília-DF (DF^sub 1^). Artificial cage inoculation oftomato plants at the two true-leaf stage, using 20 viruliferous whiteflies perplant in individual insect-proof cages, ensured 100% infection ofsusceptible tomato plants. Virus infection was confirmed by symptomdevelopment and dot-blot or squash-blot hybridization. In advanced testing,accessions of L. chilense (LA 1967), L. peruvianum (CNPH784) and L. hirsutum (PI-127827) and three selected inbred lines(TY 197, TY 198 and Tx 468-1) showed no symptoms and viral DNAwas barely detectable four weeks after inoculation, indicating good sourcesof resistance to the virus.[PUBLICATION ABSTRACT]

Background Previous studies that assessed risk factors for venous thromboembolism (VTE) in COVID-19 patients have shown inconsistent results. Our aim was to investigate VTE predictors by both logistic regression (LR) and machine learning (ML) approaches, due to their potential complementarity. Methods This substudy of a large Brazilian COVID-19 Registry included COVID-19 adult patients from 16 hospitals. Symptomatic VTE was confirmed by objective imaging. LR analysis, tree-based boosting and bagging were used to investigate the association of variables upon hospital presentation with VTE. Results Among 4,120 patients (55·5% men, 39·3% critical patients), VTE was confirmed in 6·7%. In multivariate LR analysis, obesity (OR 1·50, 95%CI 1·11-2·02); being an ex-smoker (OR 1·44, 95%CI 1·03-2·01); surgery ≤ 90 days (OR 2·20, 95%CI 1·14-4·23); axillary temperature (OR 1·41, 95%CI 1·22-1·63); D-dimer ≥  4 times above the upper limit of reference value (OR 2·16, 95%CI 1·26-3·67), lactate (OR 1·10, 95%CI 1·02-1·19), C-reactive protein levels (CRP, OR 1·09, 95% CI 1·01-1·18); and neutrophil count (OR 1·04, 95%CI 1·005-1·075) were independent predictors of VTE. Atrial fibrillation, peripheral oxygen saturation/inspired oxygen fraction (SF) ratio and prophylactic use of anticoagulants were protective. Temperature at admission, SF ratio, neutrophil count, D-dimer, CRP and lactate levels were also identified as predictors by ML methods. Conclusion By using ML and LR analyse, we showed that D-dimer, axillary temperature, neutrophil count, CRP and lactate levels are risk factors for VTE in COVID-19 patients.