O vulcanismo alta-sílica da região do Tupanci, NW do Escudo Sul-Rio-Grandense: faciologia, petrografia e litoquímica

Volcanic and hypabyssal acid rocks occur in the Tupanci area, NW portion of the Sul-Rio-Grandense Shield. These rocks are stratigraphically correlated to the Acampamento Velho Formation (~550 Ma), at the Camaquã Basin. This region has the northernmost exposure of this volcanic episode, which comprises effusive/ hypabyssal and pyroclastic rocks, with dominantly acid composition and sodic-alkaline affinity, whose genetic processes are linked to the post-collisional stages of the Brasiliano/Pan-Africano orogenic cycle. Acid volcanic rocks occur mainly as effusive deposits and also as pyroclastic deposits, in two Cerros (Hills): Tupanci and Picados. Cerro Tupanci defines an elongated (N-S) sub-volcanic intrusion of porphyritic rhyolites with phenocrysts of alkali feldspar and quartz surrounded by equigranular-fine-grained to aphanitic quartz-feldspar matrix, with a strong flow foliation on border regions. Cerro dos Picados shows texturally similar rhyolites, but with aphanitic to glassy matrix and presence of biotite; and pyroclastic deposits, characterized by rhyolitic ignimbrites. Ignimbrites occur in two facies: lithic-rich, with few devitrified and poorly elongated pumice and crystal fragments; and rheomorphic, with abundance of devitrified pumices with detachable eutaxitic texture, crystal fragments and rarely lithic fragments. Geochemical behavior allows to classify the magmatism as silica oversaturated, similar to the systems with high-silica, alkaline affinity and a metaluminous to slightly peralkaline trend with similar characteristics to “A” type granites. Petrographic and lithochemical data indicate a genetic linkage with the Acampamento Velho Formation magmatismA região do Tupanci, noroeste do Escudo Sul-Rio-Grandense (ESRG), apresenta depósi- tos vulcânicos ácidos, estratigraficamente correlacionados à Formação Acampamento Velho (~550 Ma), da Bacia do Camaquã.  Esta região é a exposição mais setentrional deste episódio vulcânico, caracterizado por sequências efusivas e piroclásticas, dominantemente ácidas, afinidade alcalina alta sílica sódica e vinculadas ao magmatismo pós-colisional do ciclo orogênico Brasiliano/Pan- -Africano no ESRG. As vulcânicas ácidas ocorrem na forma de depósitos efusivos e, em menor volu- me, piroclásticos, distribuídas em dois cerros: Cerro Tupanci e Cerro dos Picados. O Cerro Tupanci é uma intrusão subvulcânica alongada N-S, representada por riolitos porfiríticos, com fenocristais de sanidina e quartzo e uma matriz quartzo-feldspática equigranular fina a afanítica, com intensa foliação de fluxo nas regiões de borda. No Cerro dos Picados ocorrem riolitos texturalmente se- melhantes, porém com matriz afanítica de aspecto vítreo e presença de biotita, além de depósitos piroclásticos de ignimbritos riolíticos, divididos em duas fácies: uma rica em líticos, com púmices devitrificados e pouco estirados, além de pequenos e raros cristaloclastos; e outra de ignimbritos reomórficos, com abundantes púmices devitrificados, destacada textura eutaxítica, mais rica em cristaloclastos e raros litoclastos. O comportamento geoquímico de ambas as fácies classifica o magmatismo como supersaturado em sílica, semelhante aos sistemas de alta sílica, afinidade alcali- na sódica, e tendência metaluminosa a levemente peralcalina, com características dos granitos tipo “A”. Os dados faciológicos, petrográficos e litoquímicos obtidos indicam vinculação genética destas rochas com o vulcanismo da Formação Acampamento Velho.

Os diques latíticos portadores de ouro e sulfetos da Associação Shoshonítica de Lavras do Sul – RS: petrogênese e geoquímica

The Neoproterozoic Lavras do Sul Shoshonitic Association (LSSA) is situated in the southernmost Brazil, and hosts Au-Cu-sulphide mineralizations, that, according to some authors, could be related to porphyry copper-gold deposits. Field, petrographic, mineralogical, and geochemical data led to the identification and classification of late dikes, which crosscut the hypabissal monzonites, andesites and lamprophyres of LSSA, in three main types: authoclastic composite dikes, latitic dikes, and amphibole-bearing latitic dikes. Their large lithological and textural variation is attributed to magmatic differentiation, mineral segregation, and, magma mingling processes. The dikes show shoshonitic affinity, with K2 O > (Na2 O – 2), contain rela-  tively high amounts of Rb, Ba, and Sr, and low to moderate contents of Nb, Zr, HREE, features that are characteristic of the LSSA. Two main compositional trends were observed: (i) an high-Ti trend, with higher contents of Fe2 O3 t, P2 O5 , HFS, LILE and REE, and lower K2 O / Na2 O ratios( 1.4. The  lower K2 O / Na2 O ratios of high-Ti dikes indicate an evolution of magma sources and processes towards more sodic, silica-saturated alkaline compositions, like is usually described in the post-collisional magmatism. Magmatic crystallization and, the concurrent volatile enrichment, together with Au-S-Cl complexes formation, led to the fluid oversaturation of the magma system and to the second boiling point, which caused the dike vesiculation in the late magmatic stages. The lamprophyre magma is admitted as a possible source of Au and S in the magmatic system. Comingling between the trachyte or latite magmas with the lamprophyre one, can have caused the increase of volatiles and the consequent oxidation of this system, so, promoting the fluid phase separation, the breakdown of complexes, and precipitation of Au-bearing magmatic sulphides, as well as the hydrothermal fluid phase generation.A Associação Shoshonítica de Lavras do Sul (ASLS), situada no extremo sul do Brasil, tem idade neoproterozóica e hospeda ocorrências importantes de Au-Cu-sulfetos, relacionadas por alguns autores a depósitos do tipo Cu-Au pórfiro. Dados de campo, petrográficos, mineralógicos e geoquímicos permitiram identificar e classificar os diques que ocorrem na ASLS cortando os monzonitos hipabissais, andesitos e lamprófiros, em três tipos principais: diques compostos autoclásticos, diques latíticos e diques latíticos com anfibólio. Sua grande variedade litológica e textural é resultado da diferenciação magmática, segregação mineral e processos de mistura de magmas. Os diques mostram afinidade shoshonítica, com teores de K2O > (Na2O –2), acompanhados de conteúdos elevados de Rb, Ba e Sr e baixos a moderados de Nb, Zr e ETRP, assinatura típica da Associação Shoshonítica de Lavras do Sul. Os dados obtidos permitiram identificar dois trends composicionais: um alto-Ti, enriquecido em Fe2O3t, P2O5, HFS, LILE e ETR, com razões K2O/Na2O 1,4. Os diques alto-Ti, com menores razões K2O/Na2O indicam uma evolução das fontes e processos no sentido da produção de magmas alcalinos saturados em sílica mais sódicos, como é comum na evolução do magmatismo pós-colisional. A cristalização dos magmas e o progressivo enriquecimento dos voláteis e de complexos de Au-S-Cl geraram uma supersaturação do sistema, causando o segundo ponto de ebulição e a vesiculação de porções dos diques. Admite-se que o magma lamprofírico pode ser a fonte principal do ouro e enxofre do sistema. A mistura dos magmas latíticos ou traquíticos com os lamprofíricos, pode ser responsável por um aumento do potencial de oxidação e dos voláteis no sistema, desencadeando assim a separação da fase volátil, a desestabilização dos complexos e a precipitação dos sulfetos magmáticos portadores de Au, além da própria formação das soluções hidrotermais

Composite carbon materials from winery composted waste for the treatment of effluents contaminated with ketoprofen and 2-nitrophenol

The present work consisted of preparing and characterizing composite carbon materials (WRCC) from raw winery residues (WR) activated with zinc chloride to produce a carbon adsorbent. The WRCC was used for the adsorption of emerging contaminants in aqueous media. The WRCC presented a morphology with favorable characteristics for the adsorption process, giving an abundant porous structure with pores of different sizes. The results show the WRCC’s effectiveness, presenting surface area values (227 m2 g−1) and total pore volume (0.175 cm3 g−1). The general order kinetic model predicted the experimental curves sufficiently. The Sips model better described the two adsorbates' equilibrium data, with maximum adsorption capacities of 376.0 and 119.6 mg g−1 for 2-nitrophenol and ketoprofen, respectively. The WRCC carbon material was also highly efficient, with maximum removal of 81.4% and 94% in 1000 mg L−1 of the compounds 2-nitrophenol and ketoprofen. Finally, the prepared material has essential characteristics that make it an efficient adsorbent in treating effluents with emerging contaminants

Early liver function improvement following successful treatment of chronic hepatitis C in patients with decompensated cirrhosis: a real-life study

OBJECTIVES: Despite higher rates of sustained virologic response (SVR), important concerns remain when patients with decompensated cirrhosis due to hepatitis C virus (HCV) are treated with direct-acting antiviral agents (DAA). Questions include efficacy, safety, and the magnitude of liver function improvement. Here, we aimed to evaluate HCV treatment data in this specific population in Brazil. METHODS: We included 85 patients with decompensated cirrhosis submitted to HCV therapy with DAA followed at two academic tertiary centers in the southeastern region of Brazil. RESULTS: Seventy-nine patients (92.9%) were Child-Pugh (CP) score B, and six (7.1%) were CP score C. The mean MELD score was 12.86. The most common treatment was sofosbuvir plus daclatasvir±ribavirin for 24 weeks. The overall intention-to-treat (ITT) SVR rate was 87.4% (74/85) and modified-ITT 96.1% (74/77). ITT SVR was associated with lower baseline INR values (p=0.029). Adverse events (AE) occurred in 57.9% (44/76) of patients. Serious AE were reported in 12.8% (10/78), and were related to the presence of hepatic encephalopathy (p=0.027). SVR was associated with improvement in CP (p<0.0001) and MELD scores (p=0.021). Among baseline CP score B patients with SVR, 46% (29/63) regressed to CP score A. Ascites was independently associated with no improvement in liver function in patients who achieved SVR (p=0.001; OR:39.285; 95% CI:4.301-258.832). CONCLUSIONS: Patients with decompensated HCV cirrhosis showed a high SVR rate with interferon-free therapy. Early liver function improvement occurred after successful HCV eradication. However, long-term follow-up of these patients after SVR remains strongly advised. &nbsp

Effects of supplementation of tropical fruit processing by-products on lipid profile, retinol levels and intestinal function in Wistar rats

Abstract Fruits agro-industrial by-products may have a great variety of bioactive compounds that promote health. Thus, the effects of supplementation with acerola, cashew and guava processing by-products for 28 days on retinol level, lipid profile and on some aspects related to intestinal function in rats were investigated. The animals supplemented with different fruit by-products presented similar weight gain, faecal pH values and intestinal epithelial structures; however, they showed higher moisture and Lactobacillus spp. and Bifidobacterium spp. counts in faeces compared to the control group. Supplementation with the cashew by-product decreased the blood glucose, acerola and guava by-products reduced serum lipid levels and all fruit by-products tested increased serum and hepatic retinol. The results indicated that acerola and guava by-products possess a potential hypolipidemic effect. The three fruit by-products increase the hepatic retinol deposition and the faecal populations of beneficial bacterial groups and modulated aspects of intestinal function. The findings of this study can contribute to sustainable fruticulture and support future clinical studies with the supplementation of by-products