Abstract The flotation mechanism of galena with xanthate as the collector is generally explained based on the mixed potential of the pulp, in which an anodic electron transfer reaction from the collector to the mineral is combined with an O2 cathodic reduction. Sodium sulphide, often used as a mineral activator, strongly influences the pulp's mixed potential, and depending on the dosage applied, it can become a galena depressor reagent. In this way, the current study assesses galena flotability in the absence of collector, as well as in the presence of the collector potassium amyl xanthate (PAX) and sodium sulphide. The effect of an extremely cathodic potential was also studied through the addition of hydrogen peroxide. In addition, the effect of different stages in the oxidation of the galena surface on the flotability was investigated. Moreover, the zeta potential was measured and contact angle (wettability) tests were carried out. The contact angle measurements were taken for a distilled water, PAX solution and for a mixture of PAX and sodium sulphide solution on the oxidized and non-oxidized surface of galena. All the results showed that galena could be floated in all the PAX concentrations tested. It was observed that a moderate oxidation in the galena surface may contribute to an improvement of its flotation with PAX. However, extremely anodic and cathodic potentials cause flotability close to zero. The zeta potential results showed that sodium sulphide affected the interaction between PAX and galena. The measurements of the contact angle corroborated the results obtained in the microflotation tests. pulp O reduction activator pulps s applied reagent way (PAX peroxide investigated Moreover wettability (wettability out water nonoxidized non tested However zero

Abstract The control of weeds in agriculture is mainly conducted with the use of synthetic herbicides. However, environmental and human health concerns and increased resistance of weeds to existing herbicides have increased the pressure on researchers to find new active ingredients for weed control which present low toxicity to non-target organisms, are environmentally safe, and can be applied at low concentrations. It is herein described the synthesis of glycerol-fluorinated triazole derivatives and evaluation of their phytotoxic and cytogenotoxic activities. Starting from glycerol, ten fluorinated triazole derivatives were prepared in four steps. The assessment of them on Lactuca sativa revealed that they present effects on phytotoxic and cytogenotoxic parameters with different degrees of efficiency. The compounds 4a, 4b, 4d, 4e, 4i, and 4j have pre-emergent inhibition behavior, while all the investigated compounds showed post emergent effect. Mechanism of action as clastogenic, aneugenic, and epigenetic were observed in the lettuce root meristematic cells, with alterations as stick chromosome, bridge, delay, c-metaphase, and loss. It is believed that glycerol-fluorinated triazole derivatives possess a scaffold that can be explored towards the development of new chemicals for the control of weed species.

Abstract The cold roller die process increases the tensile strength and decreases the ductility of steel wire. Annealing heat treatment is applied to restore mechanical properties, but this is a costly process. This research shows that it is possible to control the mechanical properties of ultra-low carbon steel wire inducing the Bauschinger effect and relieving residual steel stresses. The present study uses several pulleys to promote and control the Bauschinger effect magnitude through alternated cyclic bending. A Completely Randomized Design, a regression study, and the Akaike Information Criterion were used to understand the relationship between the quantity and diameter of pulleys and the influence on the magnitude of the Bauschinger effect. Statistical models showed that it is possible to have a maximum increase of 103% in uniform elongation and a maximum decrease of 14% in yield strength. An interaction between the factors studied in controlling the Bauschinger effect magnitude was confirmed.

This investigation describes the synthesis of eugenol analogs presenting 1,2,3-triazole fragments and evaluation of their antileishmanial activity. The alkylation of guaiacol (1) with allyl bromide afforded 1-(allyloxy)-2-methoxybenzene (2) (93% yield). The Claisen rearrangement conducted with 1 gave ortho eugenol (3) (82% yield). Alkylation procedures performed with 3 produced 1-allyl-3-methoxy-2-(prop-2-yn-1-yloxy)benzene (4) (73% yield) and 1-allyl-3-methoxy-2-(pent-4-yn-1-yloxy)benzene (6) (53% yield). The copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reactions involving alkynes 4 and 6 with different benzylic azides afforded twenty-two eugenol analogs with 1,2,3-triazole functionalities (48-93% yield). We screened the compounds at 10 μmol L 1 against Leishmania braziliensis intracellular amastigotes during macrophage infection. The action of these compounds was compared with the known leishmanicidal drug amphotericin B. None of the analogs were toxic to macrophages at 10 μmol L-1. The cytotoxic concentration at 50% (CC50), effective concentration at 50% (EC50), and selectivity index (SI) were determined to the best compounds 4-((2-allyl-6-methoxy)phenoxymethyl)-1-(4-chlorobenzyl)-1 H-1,2,3-triazole (8c) and 4-((2-allyl-6-methoxy)phenoxymethyl)-1-(4-trifluoromethoxybenzyl)-1 H-1,2,3-triazole (8h). They showed a significant leishmanicidal effect, with EC50 of 28.09 µmol L-1 (8c) and 52.03 µmol L-1 (8h). The SIs were 9.7 for 8c and > 5.7 for 8h. These compounds have the potential as new leishmanicidal agents against L. braziliensis and may represent a starting point for the development of alternative treatments for cutaneous leishmaniasis.

Eugenol (C10H12O2, 4-allyl-2-methoxyphenol) is a phenolic natural product that has several biological activities and possibilities of applications. It is herein described the synthesis of eugenol-fluorinated triazole derivatives and evaluation of their fungicidal activity. The reaction of eugenol with epichlorohydrin resulted in the preparation of (±)-2-((4-allyl-2-methoxyphenoxy)methyl)oxirane (1) in 88% yield. The azidolysis of 1 with sodium azide gave the azido-alcohol (±)-1-(4-allyl-2-methoxyphenoxy)-3-azidopropan-2-ol (2) in 94% yield. The CuAAc reaction between compound 2 and different terminal alkynes afforded a series of eleven derivatives (3a 3k) within 48-80% yield. All the synthesized compounds were characterized by infrared (IR) and nuclear magnetic resonance (1H and 13C) spectroscopies and high-resolution mass spectrometry. The in vitro inhibitory activity of the compounds on the mycelial growth of a strain of Colletotrichum sp., that causes anthracnose disease on papaya fruits, was evaluated. The best result was observed for compound 1-(4-allyl-2-methoxyphenoxy)-3-(4-(2-fluorophenyl)-1H-1,2,3-triazol-1-yl)propan-2-ol (3d) that showed a mean growth-inhibition zone of 5.10 mm in a well-diffusion assay, and may serve as a template for additional structural modifications, aiming for more potent fungicidal activity.

The control of fungal species in agriculture is mainly conducted with the use of contact or systemic fungicides. However, environmental and human health concerns and increased resistance of fungal species to existing fungicides have increased the pressure on researchers to find new active ingredients for fungal control which present low toxicity to non-target organisms, are environmentally safe, and can be applied at very low concentrations. It is herein described the synthesis of eleven glycerol triazole containing compounds (ten of them fluorinated derivatives) and evaluation of their fungicidal activity. Eight out of eleven synthesized compounds are novel and all of the glycerol derivatives were characterized using infrared (IR), nuclear magnetic ressonance (NMR), and mass spectrometry (MS) techniques. Theoretical calculations were also carried out and the results are discussed. Starting from glycerol, the triazole derivatives were prepared in four steps. Evaluation of them against Colletrotricum gloesporioides showed that compound 1-((2,2-dimethyl-1,3 dioxolan-4-yl)methyl)-4-(2-fluorophenyl)-1H-1,2,3-triazole (4d) (ED50 = 59.14 µg mL-1) was slightly more active than commercial fungicide tebuconazole (61.35 µg mL-1). Compound 4d presented attractive physicochemical features for agrochemical purposes as revealed by the calculated physicochemical parameters. It is believed that glycerol-fluorinated triazole derivatives can be explored towards the development of new chemicals for the control of fungal species.

A novel free PhotoMetrix UVC is proposed for both the operation of a universal serial bus video camera (UVC) and multivariate image analysis, allowing a full solution for point-of-use analysis. A UVC was placed in an open-source 3D-printed chamber illuminated by a white light-emitting diode (LED) with controlled intensity of light. The digital images captured were converted into red, green, and blue (RGB) histograms, and regression models were used within the app. As a proof-of-concept, four adulterants in raw milk samples were determined. The coefficient of determination (R2Cal) for all models was higher than 0.99, and no significant differences (p < 0.05) between the measured and predicted values were identified. The root mean square error of calibration (RMSEC) and root mean square error of cross validation (RMSECV) were satisfactory, with values less than 0.1 and 0.7 g L-1, respectively. The recoveries ranged from 90 to 120% in spiked milk samples, and partial least square (PLS) models showed root mean square error of prediction (RMSEP) of 0.28, 0.33, 0.48 and 0.39 g L-1 for chloride, hypochlorite, hydrogen peroxide and starch, respectively. The PhotoMetrix UVC app was feasible for the colorimetric chemical analysis using a smartphone improving the applicability, mobility, and usability.

Resumo Esta análise aplica a revisão sistemática como metodologia para identificar, analisar e interpretar dados sobre o uso de índices de qualidade da água para consumo humano. Os artigos científicos foram pesquisados nas bases de dados “PubMed”, “Scielo”, “Science Direct” e “Web of Science”, usando as palavras-chave “água potável” e “índice de qualidade da água”, com um intervalo personalizado entre 2000 e 2020. Os resultados indicaram 82573 artigos publicados, sendo 16 deles selecionados após um processo de filtragem. Verificou-se a ocorrência de 11 índices de qualidade da água, incluindo 47 parâmetros de qualidade da água utilizados para avaliar a qualidade da água potável, destacando que os parâmetros pH, nitrato, turbidez, cloreto e sulfato foram os mais utilizados, citados em 10 dos 16 artigos selecionados (62,5%). Sugerimos que pesquisas futuras procurem propor indicadores regionalizados de qualidade da água para consumo, a fim de considerar aspectos locais no processo de avaliação e determinar prioridades de intervenção por órgãos de vigilância em saúde.

Abstract This analysis applied systematic review as a methodology for identifying, analyzing and interpreting data on the use of water quality indices for human consumption. Scientific articles were searched in the “PubMed”, “Scielo”, “ScienceDirect” and “Web of Science" databases, using the keywords “drinking water” and “water quality index”, with a custom interval between 2000 and 2020. The results indicated 82,573 published articles, with 16 of them being selected after a filtering process. The occurrence of 11 water quality indices was verified, including 47 water quality parameters used to assess the quality of drinking water, highlighting that the parameters pH, Nitrate, Turbidity, Chloride and Sulfate were the most used, cited in 10 of the 16 articles selected (62,5%). We suggest that future studies seek to propose regionalized water quality indicators for consumption, in order to consider local aspects in the evaluation process and to determine intervention priorities by health surveillance agencies.

It is herein described the synthesis of a series of thirty novel 1,2,3-triazole-1,4 disubstituted compounds inspired on the known SRPKs inhibitor N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)isonicotinamide (SRPIN340) and biological evaluation of them against human glioblastoma multiforme cell line U87MG. Starting with 1-fluoro-2 nitro-4-(trifluoromethyl)benzene (1), the substances were prepared via a five-step synthetic route. The crucial step corresponded to the copper-catalyzed cycloaddition reaction between trifluoromethyl phenyl azides and different alkynes. In general, the compounds were obtained with good yields and they were characterized utilizing spectroscopic (IR and NMR) and spectrometric (HRMS) techniques. The evaluation of the synthesized compounds at three different treatment time (24 h, 48 h, and 72 h) and concentrations (50, 100, and 150 µmol L-1) revealed that five derivatives were capable of reducing cell viability by 50% after 72 h of treatment at the highest concentration. On the contrary, three derivatives significantly increased cell viability being this effect more pronounced after 48 h of treatment. In this regard, it stands out the compound 2-((1-(2-morpholino-5-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-4-yl)methyl)isoindoline-1,3-dione (7) which increased cell viability in approximately 300% after 48 h of treatment at 100 µmol L-1. The substances that increased cell viaiblity present as common structural features the presence of a saturated nitrogen-containing six-membered ring and carbonylated fragments.

Resumo Esta pesquisa teve como objetivo desenvolver um índice de qualidade da água para abastecimento público na Região do Vale do Rio Pardo, RS, Brasil, IQA-VRP, utilizando o banco de dados da 13ª Coordenadoria Regional de Saúde, totalizando 1175 amostras. Um processo de filtragem resultou em 285 amostras com as variáveis Cloro residual livre, turbidez, cor aparente, pH, fluoretos, coliformes totais e Escherichia coli. Para fins de potabilidade, foi utilizado o Índice de Qualidade da Água desenvolvido pela Companhia de Saneamento de Goiás, Brasil. Realizamos uma calibração multivariada dos pesos de importância dos parâmetros incluídos no índice original, resultando no IQA-VRP. Comparando as medianas dos dois índices, verificou-se que houve diferenças significativas (p<0,05), qualificando o IQA-VRP como mais restritivo. Os resultados indicaram que 89,8% das amostras foram classificadas como produtos não conformes pelo IQA-VRP, enquanto 10,2% foram classificadas como produtos conformes, e das 285 amostras analisadas, 72 amostras de cloro, 12 de coliformes totais, 5 de E. coli, 2 de cor, 200 de flúor e 26 de pH, estavam abaixo ou acima dos valores mínimos ou máximos exigidos pela legislação brasileira. O pH e o flúor correspondem às variáveis críticas da região de estudo, pois foram os parâmetros que apresentaram os maiores aumentos nos pesos relativos comparando o índice original com o calibrado. Esses resultados confirmam o uso do IQA-VRP como ferramenta eficiente para avaliar a qualidade da água potável em sistemas lóticos subtropicais e temperados brasileiros.

Abstract This research developed a Water Quality Index (WQI) for public supply in the Vale do Rio Pardo Region, RS, Brazil (WQI-VRP), from the database of the 13th Regional Health Coordination, totaling 1175 samples. A filtration process resulted in 285 samples with the variables free residual chlorine, turbidity, apparent color, pH, fluoride, total coliforms and Escherichia coli. For water consumption purposes, the Water Quality Index developed by the Sanitation Company of Goiás, Brazil, was used. A multivariate calibration of the weights of importance of the parameters included in the original index was performed, resulting in the WQI-VRP. Comparing the medians of the two indexes, it was found that there were significant differences (p<0.05), qualifying the WQI-VRP as more restrictive. The results indicated that 89.8% of the samples were classified as non-compliant samples by WQI-VRP, while 10.2% were classified as compliant samples. Of the 285 samples analyzed, 72 samples of chlorine, 12 of total coliform, 5 of E. coli, 2 of color, 200 of fluoride and 26 of pH, were below or above the minimum or maximum values required by Brazilian legislation. The pH and fluoride correspond to the critical variables of the study region, as they were the parameters that showed the greatest increases in relative weights when comparing the original index with the calibrated one. These results confirm the use of the WQI-VRP as an efficient tool to assess the quality of drinking water in Brazilian subtropical and temperate lotic systems.

RESUMO Com a expansão da produção agrícola, há a substituição de áreas de Cerrado nativo por outras formas de uso do solo. Assim, objetivou-se avaliar alterações no fracionamento físico do carbono orgânico em áreas submetidas a diferentes usos do solo no Cerrado. Os tratamentos, com cinco repetições, corresponderam às seguintes formas de uso: área sob plantio convencional, área sob plantio de pastagem, área sob plantio de eucalipto e área sob vegetação nativa de Cerrado nas profundidades de 0-5, 5-10, 10-15 e 15-20 cm no munícipio de Luís Eduardo Magalhães, BA. Os maiores teores e estoques de carbono foram encontrados para a área de eucalipto, iguais à área sob vegetação nativa de Cerrado. Já os estoques de carbono particulado foram superiores na área sob pastagem na profundidade de até 10 cm, não diferenciando da área sob Cerrado nativo. A pastagem e o eucalipto apresentaram efeito positivo no índice de manejo do carbono, independentemente da profundidade.

ABSTRACT With the expansion of agricultural production, native Cerrado areas are replaced with other forms of land use. Thus, the objective of this study was to evaluate changes in the physical fractionation of organic carbon (C) in areas under different forms of land use in the Cerrado. The treatments, with five repetitions, corresponded to the following forms of use: area under conventional tillage, area under pasture plantation, area under eucalyptus plantation and area under native Cerrado vegetation, at the depths of 0-5, 5-10, 10-15 and 15-20 cm in the municipality of Luis Eduardo Magalhães, BA, Brazil. The highest C contents and stocks were found in the eucalyptus area, which were equal to those of the area under native Cerrado vegetation, while particulate C stocks were higher in the area under pasture at the depth up to 10 cm, not differing from the area under native Cerrado. Pasture and eucalyptus had positive effect on C management index, regardless of depth.

RESUMO O solo representa um importante componente no ciclo biogeoquímico do carbono (C) e do nitrogênio (N). Objetivou-se, nesta pesquisa, avaliar as mudanças provocadas por diferentes formas de uso do solo sobre os estoques de carbono e nitrogênio em áreas de Cerrado em profundidade de até 60 cm: área sob plantio convencional, plantio direto, pastagem, eucalipto e área sob vegetação nativa de Cerrado na região de Luís Eduardo Magalhães, BA. O maior teor de C foi encontrado para área de plantio direto na camada superficial até 10 cm; porém, houve decréscimo em seu teor ao longo das profundidades. Áreas sob plantio convencional apresentaram valores menores de estoque de C na camada superficial (0-5 cm) e abaixo de 20 cm. Entre estas, os estoques de C foram significativamente inferiores em comparação à utilização de pastagem e eucalipto na profundidade de até 40 cm. Considerando a profundidade de 0-60 cm, o maior estoque de C foi encontrado nas áreas sob vegetação nativa, com 62,81 Mg ha-1, seguida pela área sob cultivo de eucalipto, com 60,70 Mg ha-1. Os menores estoques de C foram encontrados nas áreas sob uso convencional, com 44,87 Mg ha-1. O plantio convencional reduziu os estoques de N em até 61 e 56% em relação às áreas sob vegetação nativa de Cerrado e plantio de eucalipto, respectivamente, ambas na profundidade de até 10 cm. Portanto, práticas de uso do solo como eucalipto e plantio direto contribuem para armazenar carbono e nitrogênio ao longo do tempo.

ABSTRACT The soil is an important component in the biogeochemical cycling of carbon (C) and nitrogen (N). The objective of this study was to evaluate the changes caused by different types of land use on the C and N stocks in areas of Cerrado at different depths: area under conventional tillage, no-tillage, grazing, eucalyptus and area under native vegetation of Cerrado in the municipality of Luis Eduardo Magalhães, BA, Brazil. The highest C content was found for no-tillage area in the surface layer up to 10 cm; however, there was a decrease in its content along the depths. Areas under no-tillage had lower values of C in the surface layer (0-5 cm) and below 20 cm. Among these, C stocks were significantly lower compared to the use of grass and eucalyptus at the depth of up to 40 cm. Considering the depth of 0-60 cm, the highest C stock was found in areas under native vegetation, 62.81 Mg ha-1, followed by the area under cultivation with eucalyptus, 60.70 Mg ha-1. The lowest C stocks were found in areas under conventional use, 44.87 Mg ha-1. Conventional planting reduced N stocks by up to 61 and 56% when compared to areas under native Cerrado vegetation and eucalyptus plantations, respectively, both at a depth of up to 10 cm. Therefore, land use practices such as eucalyptus cultivation and no-tillage contribute to C and N storage over time.

Herein, the synthesis of nine novel glycerol-derived 4-alkyl-substituted 1,2,3-triazoles, using the CuI-catalyzed alkyne-azide cycloaddition reaction as the key step, is reported. The triazoles were characterized by infrared and nuclear magnetic resonance (NMR 1H and 13C) spectroscopy and mass spectrometry. The nine prepared compounds were evaluated with regard to their phytotoxic, antiproliferative, and fungicidal activities. The fungicidal activity was assessed on Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. All compounds presented high efficiency (comparable to the commercial fungicide tebuconazole) in inhibiting C. gloeosporioides sporulation. The phytotoxicity of the triazoles was assessed against Lactuca sativa. Germination was the less-affected parameter, whereas the most pronounced effects of the triazoles were on the germination speed index and root growth of the L. sativa seedlings. As indicators of antiproliferative activity, the mitotic index was evaluated along with chromosomal and nuclear alterations, all of which were influenced to different degrees by the triazoles. In addition, all derivatives demonstrated aneugenic and clastogenic actions in meristematic cells of L. sativa roots. Therefore, these 4-alkyl-substituted triazoles may represent a scaffold to be explored for the development of new fungicidal agents.

The use of paper devices in chemical analysis has been increased due to their low cost, high surface area, portability, and biodegradability. A novel use of paper devices is proposed using thermal infrared enthalpimetry (TIE) for a rapid, green, and high throughput determination of wine acidities. The determination of total, fixed, and volatile acidities in red, white, and sparkling wine was carried out, and the results were compared with AOAC titration method. A multichannel pipette was used for reagent addition and an infrared camera for the temperature monitoring. The pipetting and temperature measurement conditions presented direct influence in the deviations among the measurements. The results obtained by TIE presented an agreement between 96 and 104% with the reference method (AOAC 962.12), for all samples. A high sample throughput was achieved reaching 480 samples h-1 for total acidity. A significant reduction in sample volume and reagent consumption was also obtained, with energy consumption up to 60 times lower in relation to the AOAC method. The association of TIE with a paper device provided a rapid, reliable and green method for the determination of acidities of wines.