ABSTRACT Underground dams have been widely deployed in the semi-arid region of Rio Grande do Norte, a state in the Brazilian Northeast, aiming to mitigate the effects caused by water scarcity. In this study, the geographic distribution of the electrical conductivity of water of underground dams was evaluated at the end of the dry season of 2018 and at the end of the rainy season of 2019. Maps were created in ArcGIS 10.4.1 software using the Inverse Distance Weighted interpolator. The results indicated high electrical conductivity variability in the evaluated underground dams. The highest values were obtained in the eastern portion of the Rio Grande do Norte state, except for two dams, located in the municipalities of Apodi and Severiano Melo. In most of the underground dams (64%), the water has an electrical conductivity with low soil salinization potential (EC < 0.7 dS m-1). It was observed that the salinity of the underground dams is influenced by several factors, such as climate, relief, land use and occupation due to rural agglomerations and animal husbandry in the dam hydrographic basin, and intensive nutritional management with fertilizers in the dam area.

RESUMO As barragens subterrâneas é uma tecnologia de convivência com a seca amplamente construída na zana semiárida do Rio Grande do Norte como garantia da segurança hídrica devido à escassez de água superficial. Neste trabalho avaliou-se a distribuição geográfica da condutividade elétrica da água (CEa) de barragens subterrâneas, no final do período seco de 2018 e no final do período chuvoso de 2019. Após a coleta e análise da CE da água das barragens foram elaborados os mapas utilizado o software ArcGIS 10.4.1, com auxílio do interpolador de ponderação do inverso da distância. Os resultados indicaram grande variabilidade da CEa nas barragens avaliadas, sendo os maiores valores de CEa registrados nas barragens situadas na porção leste do estado do Rio Grande do Norte - Classes C2 e C3, exceto nas duas barragens localizadas nos municípios de Apodi e Severiano Melo. A maioria das águas das barragens (64%), devido à baixa CEa, não tem restrição de uso quanto aos riscos de acúmulo de sais quando utilizadas para a irrigação (CE < 0,7 dS m-1). Observou-se que a salinidade das barragens é influenciada por fatores edafoclimáticos, uso e ocupação do solo e, ainda pela presença de aglomerados rurais, criação de animais na bacia hidrográfica da barragem e, pelo uso intensivo do manejo nutricional com fertilizantes na área do barramento.

Pesticides offer a simple, cost-effective solution to ensure food supplies for a growing world population. However, their environmental performance needs improvement if pesticides are to continue contributing importantly. This study explores the insecticidal potential of a magnesium (II) metal complex containing 1,10-phenanthroline and isovanillic acid (MgPhenIso) against leaf-cutting ant (Atta sexdens rubropilosa) and its symbiotic fungus (Leucoagaricus gongylophorus). The MgPhenIso complex is easy-to-prepare, stable in solid state and in aqueous solution, and resistant to sunlight irradiation. The insecticidal activity of MgPhenIso-containing bait against A. sexdens rubropilosa and L. gongylophorus showed a delayed action mode at 2 mg g-1 (100% kill, 6th day, S50=2b) and suppressed fungus development and growth. These results, together with earlier investigations on MgPhenIso regarding its absence of toxicity to Zebrafish and Wistar male rats, emphasize the potential of this complex as an environmentally friendly insecticide candidate.

In this paper, a simple, sensitive and precise electroanalytical method was developed using a chemically-reduced graphene-oxide (CRGO)-modified glassy carbon electrode and square wave voltammetry (SWV) for determination of ciprofloxacin in pharmaceutical formulations (tablets) and milk samples. Advantages of this sensor include a potential displacement of 100 mV and a 5-fold current increase for the electrochemical oxidation of ciprofloxacin, which resulted in a highly sensitive sensor, when compared to unmodified electrode. The improved properties of the modified electrode are likely due to the formation of a porous surface evidenced by the change in electrode kinetics (thin-layer diffusion process). The proposed sensor is free from interference of sample matrix (pharmaceutical formulations and low/high-fat milk) avoiding cumbersome processes such as previous separations, solvent extraction, or sample filtration (samples were only diluted in Britton-Robinson buffer solution). The results by SWV showed a limit of detection of 0.21 µmol L-1 (correspondent to 0.069 mg L-1), which is lower than the ones obtained using other carbon-based electrodes, relative standard deviations lower than 12%, and satisfactory recoveries in the range from 84 to 109%. The results obtained were statistically similar (95% confidence level) with those performed through high-performance liquid chromatography (HPLC).

We report herein the design and synthesis via click chemistry of twelve novel triazole retinoid analogues of tamibarotene (AM80) and the evaluation of their anticancer activities against six cancer cell lines: HL60, K562, 786, HT29, MCF7 and PC3. Among the synthesized compounds, two were more potent than tamibarotene against solid tumor cells, and one of them had similar potency to tamibarotene against HL60 cells. The bioisosteric exchange between the amide group and the 1,2,3-triazole core in the retinoid agent tamibarotene (AM80) reported in this work is a valid strategy for the generation of useful compounds against cancer.

In this study, the elemental composition of nine medicinal plants and phytomedicines was evaluated by using axial view inductively coupled plasma optical emission spectrometry (ICP OES) after three digestion procedures: dry ashing (DA) and two wet digestions with a mineral acid (HNO3/H2O2) mixture on a conventional hot plate (CD), besides microwave digestion (MW). Accuracy was assessed from spinach leaves (CRM 1570a) and recovery values were in the range of 82 to 113.8%. Precisions, such as relative standard deviation (RSD), below 10% were reached. The MW procedure was preferred for its accuracy (recovery values of 94 to 102%), reduced contamination, increase in the efficiency of the decomposition process, lower residual acidity and reduced time required for digestion. The concentrations of analytes in the samples (minimum-maximum in μg g-1) were: Ca (100.71-462.20), Co (0.54-0.85), Cu (0.32-7.82), Fe (2.74-18.03), Mg (18.40-521.28), Mn (0.17-55.14), Ni (0.56-1.25) and Zn (2.96-20.92). The levels of Al, Ba, Cd, Cr, Mo, Pb, Se and V in all investigated samples were found to be below the limit of detection of ICP OES. The multielement analysis by ICP OES showed that the method is simple, fast and reliable for the multielement determination in medicinal plants and phytomedicines.

ABSTRACT Swine wastewater have high pollution load, requiring treatment before its disposal into the environment. Methane (CH4) potentially emitted for such waste is considered 21 times more polluting than Carbon dioxide (CO2), and the nitrous oxide (N2O) is considered 310 times. In this way, projects of the Clean Development Mechanism (CDM) and energy use related to the CH4 are worldwide diffused. It was evaluated the potential greenhouse gas emissions in the influent and effluent from digesters and stabilization ponds used to treat the swine wastewaters in two commercial farms operating in full cycle, located in the municipality of Oratorios-MG, Brazil. Using the methodology “AM0006” to estimate the average potential of greenhouse gases, it was identified 55% and 23% of reduction in emissions from digesters and stabilization ponds, respectively. Thus, when comparing the two systems, in the conditions that they were operated, it can be concluded that the digestion treatment system was more suitable for the treatment of swine wastewater, when taking into account only the emission of the mentioned gases, subjects of this study.

O óleo essencial das folhas de Lippia gracilis Schauer, Verbenaceae, foi examinado por CG e CG-MS. Quinze constituintes foram identificados, onde o carvacrol, p-cimeno e o γ-terpineno foram as substâncias majoritárias. No estudo in vitro, a solução a 5% do óleo de L. gracilis Schauer apresentou atividade antibacteriana para Staphylococcus aureus isolado de úlcera infectada de paciente diabético. O estudo avaliou a atividade antibacteriana da solução a 5% do óleo de L. gracilis Schauer em modelo experimental em diabetes utilizando ratos albinos Wistar machos com membro pélvico infectado com cepa de Staphylococcus aureus. No experimento foram utilizados 28 ratos Wistar distribuídos em quatro grupos (G1-branco, G2-controle negativo, G3-controle positivo, G4-teste) de sete ratos. Quando comparado o grupo G4 com G3, observou-se que a solução a 5% promoveu uma redução nas CFU/mL após 24h da administração do inóculo (S.aureus sem L. gracilis Schauer 10(8) ± 313 versus S.aureus com L. gracilis Schauer 13,28 ± 4,03). Os resultados foram expressos através do cálculo da média±EPM) e análise de variança (ANOVA). A diferença entre a concentração inibitória mínima no estudo in vitro foi determinada pelo teste Turkey (p<0.05). O teste Newman-Keuls com nível de significância (p<0.05) foi utilizado para o cálculo dos resultados obtidos no experimento in vivo. A solução a 5% do óleo essencial de Lippia gracilis Schauer apresentou boa atividade antibacteriana tanto no estudo in vivo como no in vitro.

The essential oil from Lippia gracilis Schauer (Verbenaceae) leaves was examined by GC and GC-MS. Fifteen constituents were identified. Carvacrol, p-cymene and γ-terpinene were found to be the major components. In the in vitro study, 5% solution of the Lippia gracilis Schauer oil presented antibacterial activity against Staphylococcus aureus isolated from diabetic patients with infected ulcers. The study evaluated the antibacterial activity of the 5% solution of the Lippia gracilis Schauer oil on the experimental model of diabetic adult male albino Wistar rats with leaft pelvic limb infected by Staphylococcus aureus strain. In this experiment, 28 diabetic Wistar rats were used, randomly distributed in four different groups of seven rats, (G1-white; G2-negative control; G3-positive control and G4-test). When comparing group G4 with G3, it was observed that the 5% solution presented a reduced CFU/mL level showing the antibacterial effect of the oil 24 hours after the administration of the inoculum (S .aureus without Lippia gracilis Schauer 108 ±313 versus S.aureus with Lippia gracilis Schauer 13.28±4.03). The results were expressed as mean±S.E.M. One-way analysis of the variance (ANOVA) was used. The differences between the minimum inhibitory concentration in vitro test were determined by the Tukey test (p<0.05). The Newman-Keuls test with level of significance (p<0.05) was used to measure the results in vivo. The findings have shown that 5% solution of the Lippia gracilis Schauer oil presented antibacterial activity in vitro and in vivo.

The chemical investigation of the ethanol extracts of stems, roots and leaves of Lippia sidoides led to the isolation of: steroid β-sitosterol, naphthoquinone tecomaquinone, monoterpene carvacrol, flavonoid 4',5,7-trihydroxyflavanone (naringenin), 3',4',5,7-tetrahydroxyflavanone and 4',5,7-trihydroxy-6-methoxyflavone flavonoids mixture, and 3,4,4',6'-tetrahydroxydihydrochalcone-2'-O-β-D-glucopyranoside and 4,4',6'-trihydroxydihydrochalcone-2'-O- β-D-glucopyranoside dihydrochalcones mixture. Their structures were characterized on the basis of spectral data, mainly ¹H and 13C NMR (1D and 2D) and mass spectra. The ethanol extract and isolated compounds were evaluated for their antioxidative properties using the method of inhibition of free radical DPPH (2,2-diphenyl-1-picrylhydrazyl).

A técnica electroanalítica, Voltametria de Redissolução Anódica de Onda Quadrada (VRAOQ), foi utilizada na determinação simultânea de quantidades traço dos metais tóxicos Pb(II), Cd(II) e Cu(II) em folhas de choupo (populus), utilizadas como bio-indicador, recolhidas numa área de tráfego automóvel intenso da cidade de Lisboa. As folhas, após secagem, foram submetidas a um processo de digestão ácida por microondas. Para a aplicação desta técnica à análise das folhas foi realizado um estudo de optimização dos vários parâmetros voltamétricos. O eletrodo de trabalho consistiu num filme de mercúrio depositado numa superfície de carbono vítreo. O sistema Ag/AgCl foi utilizado como referência e um fio de Platina como eletrodo auxiliar. Concentrações médias (em mg de metal/kg de matéria seca - folhas) de 2,6, 0,18 e 5,0 foram obtidas para o Pb(II), o Cd(II) e o Cu(II), respectivamente. O valor obtido para o chumbo coincide com o obtido pelo método de referência baseado na Espectrofotometria de Absorção Atômica em Forno de Grafite (EAAFG).

Square wave anodic stripping voltammetry (SWASV) was applied to the simultaneous determination of trace amounts of toxic metals Pb(II), Cd(II) and Cu(II) in white poplar (populus) leaves, used as bio indicator and gathered in a chosen area of the city of Lisbon with very high traffic intensity. The leaves were dried and subsequently exposed to an acid digestion microwave process. Square wave parameters were optimized for the voltammetric analysis of the samples. The working electrode consisted of a thin mercury film (TMFE) deposited on the surface of vitreous carbon. The pair Ag/AgCl was used as the reference electrode and a Pt wire as the auxiliary electrode. Average concentrations (in mg of metal/kg of dry matter-leaves) of 2.6, 0.18, and 5.0 were obtained for Pb(II), Cd(II) and Cu(II), respectively. The value for lead coincides with the one obtained by the reference method based on Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS).

A matched case-control study was performed to identify risk factors for measles during an epidemic that occurred in 1997 in the city of São Paulo, in the Brazilian state of the same name. Measles cases from the city of São Paulo from 1 January 1997 to 15 August 1997 were included in the study. The criteria for case definition were age below 30 years, having received no measles vaccine 5-21 days before the onset of rash, and laboratory confirmation by IgM antibodies detection. From a bank of confirmed measles cases, 130 cases for each of five age ranges (under 1 year, 1-5 years, 6-20 years, 21-24 years, and 25-29 years) were picked at random according to a systematic criterion proportional to the number of cases in seven areas of the city. Data were collected through a home survey, and for each measles case studied two controls matched by age and place of residence were selected. The matched conditional logistic regression analysis for the potential risk factors from the univariate analysis showed that the best predictors for acquiring measles during the epidemic were: lack of measles vaccination, previous contact with a measles-like disease at home or on the job, having been born either outside the state of São Paulo or in a rural area, being employed, and spending time in a semiclosed institution, such as a nursery, day care center, or school. The risk factors were not homogeneous for the different age groups. The data in the present survey suggest that, in addition to lack of vaccination, other risk factors should be considered when planning a measles vaccination strategy for a developing country.

Se realizó un estudio de casos y controles apareados para identificar los factores de riesgo de sarampión durante una epidemia que tuvo lugar en 1997 en la ciudad de São Paulo, en el estado brasileño del mismo nombre. Se incluyeron los casos de sarampión ocurridos en esa ciudad entre el 1 de enero y el 15 de agosto de 1997. Los criterios para definir los casos fueron: edad inferior a 30 años, no haber sido vacunado contra el sarampión en los 5-21 días anteriores al inicio del exantema y confirmación mediante la detección de anticuerpos IgM. A partir de un banco de datos de casos confirmados de sarampión, se seleccionaron aleatoriamente 130 casos de cada uno de los siguientes grupos de edad: menores de 1 año, 1 a 5 años, 6 a 20 años, 21 a 24 años y 25 a 29 años; la selección se hizo de acuerdo con un criterio sistemático proporcional al número de casos en siete zonas de la ciudad. Los datos fueron recolectados mediante una encuesta domiciliaria y por cada caso de sarampión se estudiaron dos controles emparejados según la edad y el lugar de residencia. El análisis de regresión logística condicional de los posibles factores de riesgo identificados en el análisis univariado reveló que los factores que mejor predecían la adquisición de la enfermedad durante la epidemia eran: 1) la ausencia de vacunación contra el sarampión; 2) el contacto previo, en casa o en el trabajo, con un caso de enfermedad similar al sarampión; 3) el haber nacido fuera de São Paulo o en una zona rural; 4) el estar empleado, y 5) el pasar parte del día en una institución semicerrada, como una guardería, un centro infantil o una escuela. Los factores de riesgo no fueron homogéneos para los diferentes grupos de edad. Los datos de este estudio indican que, además de la falta de vacunación, habría que considerar otros factores de riesgo a la hora de planificar una estrategia de vacunación contra el sarampión en países en desarrollo.