A track record of Au-Ag nanomelt generation during fuid‑mineral interactions

Recent studies have reported the signifcant role of Au-bearing nanoparticles in the formation of hydrothermal gold deposits. Despite the ever-increasing understanding of the genesis and stability of Au-bearing nanoparticles, it is still unknown how they behave when exposed to hydrothermal fuids. Here, we study the nanostructural evolution of Au–Ag nanoparticles hosted within Co-rich diarsenides and sulfarsenides of a natural hydrothermal deposit. We use high-resolution transmission electron microscopy to provide a singular glimpse of the complete melting sequence of Au–Ag nanoparticles exposed to the hydrothermal fuid during coupled dissolution–precipitation reactions of their host minerals. The interaction of Au–Ag nanoparticles with hydrothermal fuids at temperatures (400– 500 ºC) common to most hydrothermal gold deposits may promote melting and generation of Au–Ag nanomelts. This process has important implications in noble metal remobilization and accumulation during the formation of these deposits

A simple new screening tool for diagnosing imported schistosomiasis

We sought to test the sensitivity and feasibility of a Schistosoma infection screening process consisting of a scored patient consultation questionnaire and a serological diagnostic test. Prospective cross-sectional study. We collected from Schistosoma-exposed individuals a 14-point check list of clinical and laboratory data related to Schistosoma infection, alongside a serological test to detect Schistosoma spp infection. A check list score was created and compared with the risk of infection and clinical recovery through an agreement analysis. Two-hundred and fifty individuals were enrolled, of whom 220 (88%) were male and 30 (12%) female. The median age was 39 (range 18-78). One hundred-fifty (60%, 95% CI 54.9%-65.1%) had a check-list score ≥2. Serology test results were positive for 142 (56.8%, 95% CI 51.6%-62%). Chronic complications compatible with long-term Schistosoma infection were detected in 29 out of these 142 (20.4%, 95% CI 13.8%-27%).,. The median score value was 3, the area under the receiver operating characteristic (ROC) curve against serology results was 0.85 and the estimated intercept check-list questionnaire score value was 1.72 (95%, CI: 1.3-2.2). Participants with a positive serological test had a substantially higher check-list score (Cohen's kappa coefficient: 0.62, 95% CI: 0.54-0.70). Ninety four percent patients empirically treated showed a subsequent improvement in clinical and laboratory parameters. A two-component process consisting of a scored patient consultation questionnaire followed by serological assay can be a suitable strategy for screening populations at high risk of schistosomiasis infection

REE ultra-rich karst bauxite deposits in the Pedernales Peninsula, Dominican Republic: Mineralogy of REE phosphates and carbonates

Karst bauxites have recently received renewed attention for their potential as non-conventional REE sources. Karst bauxites from the Pedernales Peninsula in the Dominican Republic stand among the world's richest in REE. Bauxite ore from two deposits from this bauxite district, Aceitillar and El Turco, have been selected for this study due to their outstanding REE contents and contrasting mineralogy. REE (La to Lu) contents in Aceitillar, range from 0.07 to 0.16 wt%, and Y from 0.01 to 0.13 wt%, whereas El Turco contains between 0.28 and 1.40 wt% REE, and 0.33 to 1.48 wt% Y. The characterisation of REE mineralisation was performed through powder and monocrystal XRD, SEM-EDS, and EMP analyses. REE phosphates and carbonates reveal textural features that suggest significant REE mobilisation and re-deposition within the bauxite profile. The identified REE minerals can be classified into: i) primary monazite(-Ce) and minor monazite(-La); ii) secondary Y- and Nd-dominant phosphates; and iii) secondary Gd- and Nd-carbonates of the (hydroxyl)bastnäsite group. While monazites are ubiquitous in the two studied deposits, secondary phosphates are predominant in El Turco while secondary carbonates are exclusive of Aceitillar. This contrasting mineralogy is explained by the total concentration of carbonate and/or phosphate in the karst bauxite groundwater solutions. REE phosphates are the most stable phases at [CO32−]total/[PO43−]total ≤ 2; whereas REE carbonates are stable at near neutral pH when the total aqueous carbonate concentration is two orders of magnitude higher than that of phosphate. Results of this investigation contribute to a better understanding of the formation REE minerals in the supergene environment and can be applied in REE separation methods

Mastectomia profilática: o sentimento e a razão

We carried out a review based on the study by Hartmann et al. (1), which showed new aspects on the controversial matter of Prophylactic Mastectomy for breast cancer prevention. The results of the study indicated a dramatic 90% reduction on the relative risk for developing breast cancer. We reviewed the subject observing the matters of exposure and risk for developing breast cancer. We also assessed the results published in the literature in order to understand the magnitude of the risk and the potential benefits related to the procedure.É realizada uma revisão, baseada no artigo pioneiro de Hartmann et al. (1), que lançou um novo enfoque sobre o controverso tema da mastectomia profilática na prevenção do câncer de mama, mostrando uma dramática redução de 90% no risco relativo de desenvolver a doença. 0 assunto é revisado, observando aspectos da exposição e determinação do risco de desenvolver câncer de mama, bem como a forma de interpretar os resultados publicados de modo a compreender a magnitude risco e o potencial de benefício associado à intervenção proposta para sua redução

Pesquisa do linfonodo sentinela usando uma técnica com base no uso do 99mtecnéssio em dextran 500 e, ou corante azul vital, em pacientes com axila clinicamente negativa

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Sistemas silvipastoris com eucalipto: estocagem de carbono em diferentes espaçamentos e clones

This study aimed to compare the use of different eucalypt spacing and clones in carbon storage in six silvopastoral systems (SSP) located in Porto Firme - MG. Experiments containing six SSP were used in the field, with clones GG100, I144, and I224, hybrids of Eucalyptus grandis x Eucalyptus urophylla, in the spacing of 6m x 4m and 8m x 4m, at the ages of 60 and 96 months. The forest inventory carried out was of the census type, where all the trees had their circumference at 1,30 m in height (CAP) measured and separated into diametric classes. The volume was estimated based on the Spurr model. The wood density was calculated by the method of immersion in water and the carbon stock by the factor of 0,47. The genetic material I224, spaced 6m x 4m, had the highest potential for carbon storage. The basic density for the three clones, in 6m x 4m spacing, did not vary statistically, however, in 8m x 4m spacing, for the genetic materials GG100 and I224, there was a difference. It was possible to conclude that the genetic material I224, in 6m x 4m spacing (24 m² per plant), has the highest potential for carbon storage and that SSP with eucalypt contributes to low-carbon agriculture and mitigation of climate change.O objetivo do presente estudo foi comparar o uso de diferentes espaçamentos e clones de eucalipto na estocagem de carbono em 6 (seis) sistemas silvipastoris (SSP), localizados em Porto Firme - MG. Em campo foram utilizados experimentos contendo 6 (seis) SSP, com os clones GG100, I144, I224, híbridos de Eucalyptus grandis x Eucalyptus urophylla, nos espaçamentos de 6m x 4m e 8m x 4m, nas idades de 60 e 96 meses. O inventário florestal realizado foi do tipo censo, onde todas as árvores tiveram sua circunferência a 1,30 m de altura (CAP) mensuradas e foram separadas em classes diamétricas. O volume foi estimado baseado no modelo Spurr. A densidade da madeira foi calculada pelo método de imersão em água e o estoque de carbono pelo fator de 0,47. O material genético I224, no espaçamento de 6m x 4m, foi aquele com maior potencial de estocagem de carbono. A densidade básica para os três clones, no espaçamento de 6m x 4m, não variou estatisticamente. Porém, no espaçamento de 8m x 4m, para os materiais genéticos GG100 e I224, houve diferença. Foi possível concluir que o material genético I224, no espaçamento 6m x 4m (24 m² por planta) possui o maior potencial de estocagem de carbono e que os SSP com eucalipto contribuem para uma agricultura de baixa emissão de carbono e mitigação das mudanças climáticas.

Potencial de estocagem de carbono em sistemas silvipastoris no Brasil / Potential of carbon storage in silvopastoral systems in Brazil

A preocupação mundial acerca das mudanças climáticas motivou a elaboração de um compromisso climático, na Conferência das Partes 21 em Paris no ano de 2015. O Acordo de Paris, o qual o Brasil é signatário, prevê limitar a elevação da temperatura média do planeta em 2ºC em relação aos níveis pré-industriais. Os sistemas silvipastoris (SSP) são uma atividade incentivada pelo governo brasileiro, com potencial de mitigação estimado em 0,1360 MgC ha-1 ano-1. Dessa forma, o objetivo do presente estudo é realizar uma revisão bibliográfica sobre o potencial de estocagem e incremento de carbono em diferentes sistemas silvipastoris no Brasil, e comparar esses valores com a meta proposta na pelo país no Acordo de Paris. Para elaboração desse estudo foram levantados dados de SSP com diferentes idades, arranjos espaciais e espécies, localizados em diferentes regiões do país. O incremento médio anual em carbono encontrado nos diferentes SSP avaliados foi de 4,5613 MgC ha-1 ano-1. Esse valor é superior ao estimado pelo governo brasileiro para cumprir a sua meta de redução de emissões de gases de efeito estufa. Foi possível concluir que os SSP contribuem para a remoção de CO2 atmosférico e, portanto, devem ser incentivados para mitigação das mudanças climáticas

Urine metabolome profiling of immune-mediated inflammatory diseases

Background: Immune-mediated inflammatory diseases (IMIDs) are a group of complex and prevalent diseases where disease diagnostic and activity monitoring is highly challenging. The determination of the metabolite profiles of biological samples is becoming a powerful approach to identify new biomarkers of clinical utility. In order to identify new metabolite biomarkers of diagnosis and disease activity, we have performed the first large-scale profiling of the urine metabolome of the six most prevalent IMIDs: rheumatoid arthritis, psoriatic arthritis, psoriasis, systemic lupus erythematosus, Crohn?s disease, and ulcerative colitis. Methods: Using nuclear magnetic resonance, we analyzed the urine metabolome in a discovery cohort of 1210 patients and 100 controls. Within each IMID, two patient subgroups were recruited representing extreme disease activity (very high vs. very low). Metabolite association analysis with disease diagnosis and disease activity was performed using multivariate linear regression in order to control for the effects of clinical, epidemiological, or technical variability. After multiple test correction, the most significant metabolite biomarkers were validated in an independent cohort of 1200 patients and 200 controls. Results: In the discovery cohort, we identified 28 significant associations between urine metabolite levels and disease diagnosis and three significant metabolite associations with disease activity (PFDR < 0.05). Using the validation cohort, we validated 26 of the diagnostic associations and all three metabolite associations with disease activity (PFDR < 0.05). Combining all diagnostic biomarkers using multivariate classifiers we obtained a good disease prediction accuracy in all IMIDs and particularly high in inflammatory bowel diseases. Several of the associated metabolites were found to be commonly altered in multiple IMIDs, some of which can be considered as hub biomarkers. The analysis of the metabolic reactions connecting the IMID-associated metabolites showed an overrepresentation of citric acid cycle, phenylalanine, and glycine-serine metabolism pathways. Conclusions: This study shows that urine is a source of biomarkers of clinical utility in IMIDs. We have found that IMIDs show similar metabolic changes, particularly between clinically similar diseases and we have found, for the first time, the presence of hub metabolites. These findings represent an important step in the development of more efficient and less invasive diagnostic and disease monitoring methods in IMIDs