Mobility and fate of Thallium and other potentially harmful elements in drainage waters from a decommissioned Zn-Pb mine (North-Eastern Italian Alps)

The potential impact of decommissioned mining areas on the quality of water resources is an issue of major concern for local communities. Acid mine drainage resulting from hydrolysis and oxidation of metal sulphides associated with mineral veins or mining wastes is often responsible for leaching large amounts of potentially harmful elements (PHEs) in solution, which can be dispersed into the surrounding environment and affect the quality of the recipient water bodies. The aim of the present study was to investigate the geochemical properties of the mine drainage waters at the decommissioned Salafossa mine (North-Eastern Italian Alps), to highlight anomalous concentrations of PHEs outflowing from the currently flooded galleries and to elucidate their speciation. In spite of the Zn-Pb sulphides still present in the body ore, there is no evidence of acid drainage waters from the mine galleries as a result of the buffering effect produced by carbonate host rocks. Due to their high mobility, however, Zn and Tl are present in solution mostly in ionic form. Conversely, the less mobile Pb, is referably partitioned in the solid phase. Additionally, the oxidising conditions of the drainage waters also allow the precipitation of some PHEs (As, Cd, Pb, Tl, Zn) in the form of Fe-Mn oxy-hydroxides and carbonates, which accumulate at the bottom of the mine galleries as fine \u201csediments\u201d or concretions. Drainage waters inside the mine were found to be highly enriched in Zn (up to 16 mg L\u20101), Fe (up to 5 mg L\u20101) and Tl (up to 260 \u3bcg L\u20101). Their concentrations, however, are partially diluted in the mine due to a mixing with less mineralised waters before being discharged into the Piave River, the major tributary downstream from the mining area. Although drainage waters are still characterised by high concentrations of Tl (about 30 \u3bcg L\u20101) at their outflow, dilution in the Piave River seems to be the only natural process mitigating the impact of PHEs within the drainage basin

Venda direta do etanol: limites e potencialidades

O objetivo deste trabalho é analisar a implementação da venda direta do eta-nol no Brasil, iniciada pela Medida Provisória (MP) nº 1.063/2021 e publicada como Lei nº 14.292/2022, tornando possível a comercialização direta do etanol entre as usinas e os postos de combustíveis. Por meio de uma análise discursiva, este trabalho foca a comercialização nacional do etanol, antes da implementação da MP, destacando a venda direta como possível atenuante do preço final, bem como as posições das entidades públicas referentes ao setor. Conclui-se que a medida deve ensejar melhorias na cobrança dos impostos estaduais. Contudo, problemas relacionados à distância entre os postos e as usinas são fatores limitan-tes para essa comercialização, nesse primeiro momento, em função do processo de estocagem de grandes quantidades

Comportamento ótico de vidros e policarbonatos translúcidos frente à radiação solar

Nesse trabalho, apresentam-se valores de Fator de Calor Solar (FS) e da Transmitância da Luz Visível (Tv).para dezesseis tipos de vidros translúcidos e para seis tipos de policarbonatos translúcidos, utilizados no Brasil.Foram realizados ensaios em espectrofotômetro, com esfera integradora, para incidência normal, obtendosea curva de variação da transmissão e da reflexão na faixa espectral entre 300 e 2000 nm. A partir da integraçãodas curvas de valores obtidos em cada comprimento de onda, ponderados em função do espectro solarpadrão, foram calculados os valores de transmitância, refletância e absortância, para o espectro total e para asregiões do ultravioleta (UV), do visível e do infravermelho (IV) separadamente. Os vidros translúcidos incoloresensaiados apresentam transmitância na região do IV inferior ao visível, resultando uma relação entre oganho de luz e de calor igual ou superior a um, sendo uma boa indicação para utilização desse tipo de vidroem climas quentes. Os vidros translúcidos coloridos têm valores do FS inferiores ao vidro incolor de mesmotipo, com Tv ainda mais baixa, estando seu uso mais associado a uma questão estética do que a cuidados comganhos de calor. Todos os policarbonatos ensaiados transmitem uma parcela muito pequena no UV, e apenaso alveolar verde transmite mais na luz visível que no IV, sendo a relação entre o ganho de luz e de calor destesmateriais baixa, com exceção dos alveolares verde e incolor. Com exceção do alveolar incolor, todos possuemalta absorção da radiação solar, indicando materiais com alto ganho de calor solar e alta temperaturaradiante superficial quando expostos ao sol, o que pode causar desconforto localizado.Palavras-chave: vidros translúcidos, policarbonatos translúcidos, Fator de Calor Solar, Transmitância da luzvisível

Localization of adhesins on the surface of a pathogenic bacterial envelope through atomic force microscopy

Bacterial adhesion is the first and a significant step in establishing infection. This adhesion normally occurs in presence of flow of fluids. Therefore, bacterial adhesins must be able to provide high strength interactions with their target surface in order to maintain the adhered bacteria under hydromechanical stressing conditions. In the case of B. pertussis, a Gram-negative bacterium responsible of pertussis, a highly contagious human respiratory tract infection, an important protein participating in the adhesion process is a 220 KDa adhesin named Filamentous haemagglutinin (FHA), an outer membrane and also secreted protein that contains recognition domains to adhere to ciliated respiratory epithelial cells and macrophages. In this work, we obtained information of the cell-surface localization and distribution of the B. pertussis adhesin FHA using an antibody-functionalized AFM tip. Through the analysis of specific molecular recognition events we built a map of the spatial distribution of the adhesin which revealed a non-homogenous pattern. Moreover, our experiments showed a force induced reorganization of the adhesin in the surface of the cells, which could explain a reinforced adhesive response under external forces. This single-molecule information contributes to the understanding of basic molecular mechanisms used by bacterial pathogens to cause infectious disease and to gain insight into the structural features by which adhesins can act as force sensors under mechanical shear conditions.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort

BACKGROUND: Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. METHODS: A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. RESULTS: SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced 651 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with 651 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not 655. CONCLUSIONS: In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin

Ceftolozane/Tazobactam for Treatment of Severe ESBL-Producing Enterobacterales Infections: A Multicenter Nationwide Clinical Experience (CEFTABUSE II Study)

Background. Few data are reported in the literature about the outcome of patients with severe extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) infections treated with ceftolozane/tazobactam (C/T), in empiric or definitive therapy.Methods. A multicenter retrospective study was performed in Italy (June 2016-June 2019). Successful clinical outcome was defined as complete resolution of clinical signs/symptoms related to ESBL-E infection and lack of microbiological evidence of infection. The primary end point was to identify predictors of clinical failure of C/T therapy.Results. C/T treatment was documented in 153 patients: pneumonia was the most common diagnosis (n = 46, 30%), followed by 34 cases of complicated urinary tract infections (22.2%). Septic shock was observed in 42 (27.5%) patients. C/T was used as empiric therapy in 46 (30%) patients and as monotherapy in 127 (83%) patients. Favorable clinical outcome was observed in 128 (83.7%) patients; 25 patients were considered to have failed C/T therapy. Overall, 30-day mortality was reported for 15 (9.8%) patients. At multivariate analysis, Charlson comorbidity index &gt;4 (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.9-3.5; P = .02), septic shock (OR, 6.2; 95% CI, 3.8-7.9; P &lt; .001), and continuous renal replacement therapy (OR, 3.1; 95% CI, 1.9-5.3; P = .001) were independently associated with clinical failure, whereas empiric therapy displaying in vitro activity (OR, 0.12; 95% CI, 0.01-0.34; P &lt; .001) and adequate source control of infection (OR, 0.42; 95% CI, 0.14-0.55; P &lt; .001) were associated with clinical success.Conclusions. Data show that C/T could be a valid option in empiric and/or targeted therapy in patients with severe infections caused by ESBL-producing Enterobacterales. Clinicians should be aware of the risk of clinical failure with standard-dose C/T therapy in septic patients receiving CRRT

Mobility of trace elements in drainage waters from a zinc- lead decommissioned mine (Northeastern Italian Alps)

The Salafossa mine is located in the eastern Dolomites belonging to the Alpine chain, within the territory of the Veneto region. The mineral body excavated in Salafossa was one of the largest lead-zinc-containing mineral deposits in Europe. The two metals are in the form of sulphides (sphalerite, ZnS and galena, PbS). Mining activity started around 1550 but it was only around 1960 when the richest veins of the minerals were discovered. Mining activity definitely stopped in 1985. One of the problems that characterizes the mining area consists in the generation of acid drainage waters, resulting from oxidation of metal sulfides located in correspondence of the ore body and of tailings, with consequent leaching of large amounts of metal species in solution, such as Fe, Mn, Pb, Cu, Zn and Tl. The products of oxidation, carried by drainage waters, can be dispersed into the surrounding environment resulting negative impact on the quality of the watershed. The aim of this study was the geochemical characterization of drainage waters (DWs) from both the mine and the Piave River, the major tributary downstream the mine, in order to assess the mobility of heavy metals in the area. DWs were found to be enriched in Zn (up to 16 mg L-1), Fe (up to 5 mg L-1) and Tl (up to 260 \u3bcg L-1), and they represent the primary means by which the metal species are conveyed by the galleries of the mine to the Piave River. The Zn and Tl, due to the high mobility that characterizes them, are mostly present in solution in ionic form; conversely, the Pb, less mobile, is preferably partitioned in the solid phase. Additionally, the oxidizing conditions found in the waters also allow precipitation of some metals in the form of oxides, hydroxides and carbonates, such as Fe and Mn, which, consequently, have determined their enrichment in sediments transported by drainage waters and accumulated along the mine galleries floor. Although DWs are still characterised by high concentrations of Tl (up to 30 \u3bcg L-1) at their outflow, dilution in the Piave River seems to be a natural process mitigating the impact of trace metals within the drainage basin