Identifying sources of acid mine drainage and major hydrogeochemical processes in abandoned mine adits (Southeast Shaanxi, China).

Acid mine drainage (AMD) has resulted in significant risks to both human health and the environment of the Han River watershed. In this study, water and sediment samples from typical mine adits were selected to investigate the hydrogeochemical characteristics and assess the environmental impacts of AMD. The interactions between coexisting chemical factors, geochemical processes in the mine adit, and the causes of AMD formation are discussed based on statistical analysis, mineralogical analysis, and geochemical modeling. The results showed that the hydrochemical types of AMD consisted of SO4-Ca-Mg, SO4-Ca, and SO4-Mg, with low pH and extremely high concentrations of Fe and SO42-. The release behaviors of most heavy metals are controlled by the oxidation of sulfide minerals (mainly pyrite) and the dissolution/precipitation of secondary minerals. Along the AMD pathway in the adit, the species of Fe-hydroxy secondary minerals tend to initially increase and later decrease. The inverse model results indicated that (1) oxidative dissolution of sulfide minerals, (2) interconversion of Fe-hydroxy secondary minerals, (3) precipitation of gypsum, and (4) neutralization by calcite are the main geochemical reactions in the adit, and chlorite might be the major neutralizing mineral of AMD with calcite. Furthermore, there were two sources of AMD in abandoned mine adits: oxidation of pyrite within the adits and infiltration of AMD from the overlying waste rock dumps. The findings can provide deeper insight into hydrogeochemical processes and the formation of AMD contamination produced in abandoned mine adits under similar mining and hydrogeological conditions.

Seasonal impact of acid mine drainage on water quality and potential ecological risk in an old sulfide exploitation.

Sulfides are usually associated with deposits of metals and coal. The reactive wastes from their exploitation, typically stored in piles and tailings dams, are often the mining sector's primary source of environmental problems. The surrounding river waters can present signs of acid mine drainage, responsible for aquatic ecosystem degradation. So, the main target of the present study is to investigate the impact of this process on the water's environmental quality and potential ecological risk. The study area is located at the Iberian Pyrite Belt, in an old sulfide exploitation, closed without environmental rehabilitation measures. The results exhibit high sulfate concentrations (410,601 mg/L) and potentially toxic elements, with prominence of Fe (134,000 mg/L), overcoming many other extreme cases of AMD pollution. The Ficklin diagram exposes that most samples are classified as "high-acid, high-metal." Two of them have extreme classifications (high-acid, extreme-metal). The pH value is well below the acceptable range for the environmental quality of superficial waters (5-7), measuring at a minimum of 0.84. Regarding seasonal variability, the study showed a higher degree of contamination in dry conditions (e.g., 4,420 mg/L of Cu), while the rainy month had lower concentrations of PTE (186.8 mg/L of Cu for the same sampling point). In addition, the water does not accomplish the environmental objectives established by the EU Water Framework Directive. According to the new approach developed based on a scale adjustment, the potential ecological risk index studied indicates that most sampled sites present strong, very strong, and even extremely potential ecological risk. With a typical Mediterranean climate, the region suffers from water scarcity, predicting increasingly in the future more degrading scenarios for water environmental quality. Consequently, urgent mitigation and remediation measures are necessary to improve and preserve water quality and fulfill the objectives of the United Nations Sustainability Development Goals.

Effective capping of dissolved sulfide generated in Ulva prolifera-rich marine sediments by iron-rich red soil.

Bloom-induced macroalgal enrichment on the seafloor can substantially facilitate dissolved sulfide (DS) production through sulfate reduction. The reaction of DS with sedimentary reactive iron (Fe) is the main mechanism of DS consumption, which however usually could not effectively prevent DS accumulation caused by pulsed macroalgal enrichment. Here we used incubations to investigate the performance of Fe-rich red soil for buffering of DS produced from macroalgae (Ulva prolifera)-enriched sediment. Based on our results, a combination of red soil additions (6.8 kg/m2) before and immediately after pulsed macroalgal deposition (455 g/m2) can effectively cap DS within the red soil layer. The effective DS buffering is mainly due to ample Fe-oxide surface sites available for reaction with DS. Only a small loss (4 %) of buffering capacity after 18-d incubation suggests that the red soil is capable of prolonged DS buffering in macroalgae-enriched sediments.

Vertical distributions of megafauna on inactive vent sulfide features correspond to their feeding modes.

The discovery of inactive hydrothermal vent sulfide features near 9°50'N on the East Pacific Rise provides an opportunity to investigate the distribution and feeding ecology of communities inhabiting this type of habitat. We quantify megafaunal distributions on two features, Lucky's Mound and Sentry Spire, to determine how taxonomic composition and feeding traits vary with vertical elevation. Fifty-one morphotypes, categorized by feeding mode, were identified from three levels of the features (spire, apron, and base) and the surrounding flat oceanic rise. About half of the morphotypes (26 of 51) were only observed at the sulfide features. Passive suspension feeders were more abundant on the spires, where horizontal particulate flux is expected to be elevated, than the base or rise. Deposit feeders tended to be more abundant on the base and rise, where deposition is expected to be enhanced, but were unexpectedly abundant higher up on Sentry Spire. Community differences between the two sulfide features suggest that other processes, such as feature-specific chemoautotrophic production, may also influence distributions.

Plastic Litter Emits the Foraging Infochemical Dimethyl Sulfide after Submersion in Freshwater Rivers.

Plastic pollution is widespread throughout aquatic environments globally, with many organisms known to interact with and ingest plastic. In marine environments, microbial biofilms that form on plastic surfaces can produce the odorous compound dimethyl sulfide (DMS), which is a known foraging cue. This has been shown to increase the ingestion of plastic by some invertebrates and therefore act as a biological factor which influences the risks of plastic to marine ecosystems. In freshwater however, the production of DMS has been largely overlooked, despite the known sensitivity of some freshwater species to this compound. To address this gap, the present study analyzed the production of DMS by biofilms which formed on low-density polyethylene and polylactic acid films after 3 and 6 weeks of submersion in either a rural or an urban United Kingdom river. Using gas chromatography-mass spectrometry, the production of DMS by these biofilms was consistently identified. The amount of DMS produced varied significantly across river locations and materials, with surfaces in the urban river generally producing a stronger signal and plastics producing up to seven times more DMS than glass control surfaces. Analysis of biofilm weight and photosynthetic pigment content indicated differences in biofilm composition across conditions and suggested that DMS production was largely driven by nonphotosynthetic taxa. For the first time this work has documented the production of DMS by plastic litter after submersion in freshwater rivers. Further work is now needed to determine if, as seen in marine systems, this production of DMS can encourage the interaction of freshwater organisms with plastic litter and therefore operate as a biological risk factor in the impacts of plastic on freshwater environments. Environ Toxicol Chem 2024;43:1485-1496. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Fluorescence based methodology with greenness consideration for concurrent estimation of anti-allergic medication; application to dosage form.

A green, sensitive and rapid spectrofluorimetric method for quantitative assay of an anti-allergic medication composed of montelukast and fexofenadine mixture in raw materials and dosage form was developed. The method was based on measuring the synchronous fluorimetric peak without interference, pre-separation or pre-extraction procedures. Montelukast was analyzed at 360 nm while fexofenadine was measured at 263 nm using Δλ = 20 nm for both drugs using ethanol as diluting solvent and acetate buffer of pH 4. The assay was rectilinear over the concentration range of 1.0-10.0 µg/mL for fexofenadine and 0.1-0.6 µg/mL for montelukast. The method was full validated according to ICH guidelines. The applicability of the method enables the assay of both drugs in raw materials, synthetic mixture as well as combined tablets. Moreover, the greenness of the method was assessed using different methods including; analytical eco-scale, GAPI and AGREE. All of these methods confirm that the proposed method is an eco-friendly method.

A novel fluorescence immunoassay for the quantitative detection of florfenicol in animal-derived foods based on ZnCdSe/ZnS quantum dot labelled antibody.

Florfenicol (F), an antimicrobial agent exclusive to veterinary use within the chloramphenicol class, is extensively applied as a broad-spectrum remedy for animal diseases. Despite its efficacy, concerns arise over potential deleterious residues in animal-derived edibles, posing threats to human health. This study pioneers an innovative approach, introducing a quantum dot fluorescence-based immunoassay (FLISA) for the meticulous detection of F residues in animal-derived foods and feeds. This method demonstrates heightened sensitivity, with a detection limit of 0.3 ng/mL and a quantitative detection range of 0.6-30.4 ng/mL. Method validation, applied to diverse food sources, yields recoveries from 90.4 % to 109.7 %, featuring RSDs within 1.3 % to 8.7 %, the results showed high consistency with the national standard HPLC-MS/MS detection method. These findings underscore the method's accuracy and precision, positioning it as a promising tool for swift and reliable F residue detection, with substantial implications for fortifying food safety monitoring.

Percepção sensorial do off-odor em carnes bovinas irradiadas em embalagens á vácuo contendo carvão ativado / Off-odor perception in irradiated beef vacuum packaged with charcoal

Objetivou-se avaliar a utilização de carvão ativo na redução de compostos voláteis responsáveis pelo off-odor de carnes bovinas irradiadas. Para tal, contrafilés bovinos, embalados a vácuo, com e sem carvão ativo, e irradiados (1, 2 e 3 kGy), foram analisados quanto a formação de compostos de enxofre e quanto a percepção sensorial de off-odor. O único composto de enxofre identificado nas amostras foi o dimetil sulfeto (DMS), sendo encontrado em menor concentração nas amostras irradiadas com carvão ativo na embalagem. Independentemente da utilização do carvão, os painelistas perceberam o off-odor das carnes irradiadas em qualquer dose quando comparado à carne não-irradiada. Quando foi comparado as carnes irradiadas com carvão em relação àquelas irradiadas sem carvão, os painelistas foram capazes de identificar o off-odor apenas nas amostras irradiadas com 1 kGy. Conclui-se que o carvão ativo reduziu a concentração de DMS na embalagem de carnes irradiadas.

Burnout syndrome among undergraduate nursing students at a public university / Síndrome de Burnout entre estudantes de graduação em enfermagem de uma universidade pública / Síndrome de Burnout entre estudiantes de pregrado en enfermería de una universidad pública

OBJECTIVE: to investigate the burnout syndrome and its relationship with demographic and academic variables among undergraduate nursing students at a public university in Southern Brazil. METHOD: a quantitative study with 168 students, by applying an adaptation of the Maslach Burnout Inventory - Student Survey, validated for this study. We used descriptive and variance analysis of the data analysis. RESULTS: we found that students do not have the burnout syndrome, manifesting high average scores in Emotional Exhaustion, low in Disbelief and high in Professional Effectiveness; that younger students who perform leisure activities have greater Professional Effectiveness, unlike students in early grades with no extracurricular activities; combining work and studies negatively influenced only the Professional Effectiveness factor, while the intention of giving up influenced negatively Disbelief and Professional Effectiveness factors. CONCLUSION: the situations that lead students to Emotional Exhaustion need to be recognized, considering the specificity of their study environments. .

OBJETIVO: investigar a síndrome de Burnout e sua relação com variáveis sociodemográficas e acadêmicas, entre estudantes de graduação em enfermagem de uma universidade pública do Sul do Brasil. MÉTODO: estudo quantitativo, realizado com 168 estudantes, mediante a aplicação de uma adaptação do Maslach Burnout Inventory - Student Survey, validada para este estudo. Utilizou-se a análise descritiva e de variância para análise dos dados. RESULTADOS: constatou-se que os estudantes não apresentam a síndrome de Burnout, manifestando médias altas em exaustão emocional, baixas em descrença e altas em eficácia profissional; que estudantes mais jovens e que realizam atividades de lazer apresentam maior eficácia profissional, diferentemente de estudantes das séries iniciais e que não realizam atividades extracurriculares; conciliar trabalho e estudos influenciou negativamente apenas o fator eficácia profissional, enquanto a intenção de desistir do curso influenciou negativamente os fatores descrença e eficácia profissional. CONCLUSÃO: faz-se necessário o reconhecimento das situações que levam os estudantes à exaustão emocional, considerando a especificidade de seus ambientes de formação. .

OBJETIVO: investigar la síndrome de burnout y su relación con variables sociodemográficas y académicas, entre estudiantes de pregrado en enfermería de una universidad pública del Sur de Brasil. MÉTODO: estudio cuantitativo, desarrollado con 168 estudiantes, mediante la aplicación de una adaptación del Maslach Burnout Inventory - Student Survey, validada para fines de ese estudio. Fueron utilizados los análisis descriptivo y de variancia para analizar los datos. RESULTADOS: se constató que los estudiantes no presentan la síndrome de burnout, manifestando altos promedios en Agotamiento Emocional, bajos en Descreencia y altos en Eficacia Profesional; que estudiantes más jóvenes y que practican actividades de ocio presentan mayor Eficacia Profesional, diferentemente de estudiantes de los años iniciales sin actividades extracurriculares; conciliar trabajo y estudios influyó negativamente apenas el factor Eficacia Profesional, mientras la intención de desistir del curso influyó negativamente los factores Descreencia y Eficacia Profesional. CONCLUSIÓN: es necesario reconocer las situaciones que llevan a los estudiantes al Agotamiento Emocional, considerando la especificidad de sus ambientes de formación. .

Composition of the essential oil of leaves and roots of Allium schoenoprasum L. (Alliaceae) / Composición del aceite esencial de hojas y raíces de Allium schoenoprasum L

Essential oil from leaves and roots of Allium schoenoprasum L. (Alliaceae) were analyzed by GC/MS. The oils extracted by hydrodistillation yielded 0.02 percent and 0.03 percent for leaves and roots, respectively. Five (99.12 percent leaves) and four (98.32 percent roots) components were identified being bis-(2-sulfhydryethyl)-disulfide (72.06 percent leaves, 56.47 percent roots) the major constituent on the two oil samples while 2,4,5-trithiahexane (5.45 percent leaves, 15.90 percent roots) and tris (methylthio)-methane (4.01 percent leaves, 12.81 percent roots) were detected in lower amounts.

Los aceites esenciales de hojas y raíces de Allium schoenoprasum L. (Alliaceae fueron analizados por CG/EM. La extracción por hidrodestilación mostró un rendimiento de 0.02 por ciento y 0.03 por ciento para las hojas y raíces, respectivamente. Cinco (99.12 por ciento hojas) y cuatro (98.32 por ciento raíces) compuestos fueron identificados siendo el bis-(2-sulfidietil)-disulfuro (72.06 por ciento hojas, 56.47 por ciento raíces) el compuesto mayoritario en los dos aceites mientras que 2,4,5-tritiahexano (5.45 por ciento hojas, 15.90 por ciento raíces) y tris (metilthio)-metano (4.01 por ciento hojas, 12.81 por ciento raíces) fueron observados en menores cantidades.

Microbial degradation of sulfentrazone in a Brazilian rhodic hapludox soil

Sulfentrazone is amongst the most widely used herbicides for treating the main crops in the State of São Paulo, Brazil, but few studies are available on the biotransformation of this compound in Brazilian soils. Soil samples of Rhodic Hapludox soil were supplemented with sulfentrazone (0.7 µg active ingredient (a.i.) g-1 soil) and maintained at 27ºC. The soil moisture content was corrected to 30, 70 or 100 percent water holding capacity (WHC) and maintained constant until the end of the experimental period. Herbicide-free soil samples were used as controls. Another experiment was carried out using soil samples maintained at a constant moisture content of 70 percent WHC, supplemented or otherwise with the herbicide, and submitted to different temperatures of 15, 30 and 40º C. In both experiments, aliquots were removed after various incubation periods for the quantitative analysis of sulfentrazone residues by gas chromatography. Herbicide-degrading microorganisms were isolated and identified. After 120 days a significant effect on herbicide degradation was observed for the factor of temperature, degradation being higher at 30 and 40º C. A half-life of 91.6 days was estimated at 27º C and 70 percent WHC. The soil moisture content did not significantly affect sulfentrazone degradation and the microorganisms identified as potential sulfentrazone degraders were Nocardia brasiliensis and Penicillium sp. The present study enhanced the prospects for future studies on the bio-prospecting for microbial populations related to the degradation of sulfentrazone, and may also contribute to the development of strategies for the bioremediation of sulfentrazone-polluted soils.

Diagnóstico y tratamiento de la halitosis / Diagnosis and treatment of halitosis

Para desarrollar un plan de tratamiento efectivo, es necesario establecer un diagnóstico seguro que dependerá de la interpretación de los datos recolectados en la anamnesis del paciente, del examen clínico y de los resultados obtenidos a través de los métodos de diágnóstico (cualitativos o cuantitativos) empleados por el odontólogo. Hasta ahora, no existe un producto único para combatir la halitosis. La eficacia a corto y a largo plazo de la mayoría de los productos para el tratamiento del mal aliento no se ha establecido claramente. Los avances recientes en la comprensión de la etiología de la halitosis han permitido el desarrollo de nuevas técnicas para su evaluación y manejo.

Ensaios e métodos para determinaçäo da oxidaçäo de sulfetos em reservatórios

Rios altamente poluidos trazem, além de outros problemas, o do mau cheiro. Enquanto a soluçäo definitiva näo ocorrer, que seria a do tratamento dos resíduos liquidos lançados, torna-se necessário adotar medidas que reduzam a exalaçäo de odores. Este problema está sendo observado no Reservatório de Pirapora, na Bacia do Alto Tietê e a CETESB vêm estudando providências que o minimizem. Uma das alternativas seria o emprego do oxigênio do ar para oxidar os sulfetos. Após estudo em escala de laboratório, a CETESB desenvolveu uma metodologia para aplicaçäo em campo desta reaçäo de modo à se obter paramêtros para projeto e se conhecer a cinética das reaçöes. O presente trabalho relata e discute os equipamentos e testes utilizados neste estudo