Abstract Introduction Aging reduces functional capacity related to reduced toe plantar flexion strength. The exercise for strengthening the foot’s intrinsic muscles can be optimized using electrostimulation. Due to the scarcity of data in the literature on these methods, further studies are necessary. Objective To evaluate and compare the effects of training to strengthen the foot’s intrinsic muscles on the risk of falls in older adults. Methods This is a randomized clinical trial with 19 older patients allocated into three groups: control (CG; n = 7), exercise (EG; n = 6), and exercise+electrostimulation (EEG; n = 6). The EG received an exercise protocol for the foot’s intrinsic muscles, the EEG received the same protocol with Neuromuscular electrical stimulation (NMES), and the CG received guidance regarding preventing falls. The individuals were evaluated before and after the intervention using the Single-Limb balance test (SLBT), Functional Reach Test (FRT), Timed Up and Go (TUG), and Paper Grip Test (PGT) tests. One and two-way ANOVA was used for the statistical analysis. Statistical significance was set at p < 0.05. Results There was a significant improvement in the TUG test (9.64 ± 1.78 vs. 8.20 ± 1.94) in relation to the EG. With the EEG, there was an improvement both in the TUG (12.68 ± 4.01 vs. 10.61 ± 3.70) and in the FRT (26.37 ± 7.66 vs. 33.14±9.73) with p < 0.05). Conclusion An exercise protocol associated with electrostimulation improves performance in func-tional and dynamic balance tests in older adults.

Resumo Introdução O envelhecimento reduz a capacidade fun-cional, que está relacionada com a redução de força muscular de flexão plantar dos dedos dos pés. O exercício de fortalecimento da musculatura intrínseca do pé pode ser otimizado com o uso da eletroestimulação eletro (EENM). Devido à escassez de dados na literatura sobre a utilização desses métodos, torna-se necessário realizar novos estudos. Objetivo Avaliar e comparar os efeitos do treino de fortalecimento da musculatura intrínseca do pé no risco de queda em idosos. Métodos Trata-se de um ensaio clínico randomizado, no qual 19 idosos foram alocados em três grupos: controle (GC; n = 7), exercício (GE; n = 6) e exercício+eletroestimulação (GEE; n = 6). O GE recebeu um protocolo de exercícios para a musculatura intrínseca do pé, o GEE recebeu o mesmo protocolo seguido de EENM e o GC recebeu orientações quanto à prevenção de quedas. Os indivíduos foram avaliados antes e após a intervenção através dos testes de Apoio Unipodal (AU), Teste de Alcance Funcional (TAF), Timed Up and Go (TUG) e Paper Grip Test (PGT). Para a análise estatística, utilizou-se ANOVA 1 e 2 vias. Considerou-se estatisticamente significante um valor de p < 0,05. Resultados Observou-se melhora significativa no teste TUG (9,64 ± 1,78 vs 8,20 ± 1,94) em relação ao GE. Em relação ao GEE, houve melhora tanto no TUG (12,68 ± 4,01 vs 10,61 ± 3,70) quanto no TAF (26,37 ± 7,66 vs 33,14 ± 9,73). Conclusão Conclui-se que um protocolo de exercício associado à eletroestimulação melhora o desempenho nos testes de equilíbrio funcional e equilíbrio dinâmico em indivíduos idosos.

The NixCu(1-x)Fe2O4 (x = 0, 0.2, 0.8, 1) mixed nickel and copper ferrites were synthesized using the EDTA-Citrate complexation method and calcined at 700°C. The structure, properties and characterization of the samples were analyzed by DRX, Rietveld refinement, SEM, and DRE UV-Vis, indicating the phase formation of tetragonal (CuFe2O4 and Ni0.2Cu0.8Fe2O4) and cubic (Ni0.8Cu0.2Fe2O4 and NiFe2O4). The materials exhibited morphologies suitable for photocatalytic applications and a UV-Vis absorption range near 2 eV as expected for spinel ferrites. These materials were evaluated as photocatalysts for the degradation of Rhodamine B dye under heterogeneous photocatalysis conditions, simulating solar light irradiation, air injection, and different pH levels (2, 6, and 10). The results showed that the catalytic efficiency was higher for samples with a higher copper content and in a basic medium. Therefore, NixCu(1-x)Fe2O4 mixed ferrites have promising potential as photocatalysts.

RESUMO Este estudo investiga a influência da governança corporativa na relação entre o uso de derivativos financeiros e o valor da firma no contexto brasileiro. Nós usamos dados longitudinais de 241 companhias abertas ao longo do período de 2006 a 2017. As empresas são divididas em dois grupos: com melhor governança (listadas nos segmentos prêmios da B3 - Nível 1, Nível 2 e Novo Mercado); e com pior governança (listadas no segmento Tradicional da B3). Quando mitigados possíveis problemas de endogeneidade pelo Método dos Momentos Generalizado Sistêmico, os resultados indicam que o emprego de swaps diminui o valor das firmas bem governadas que são menos endividadas. Nós interpretamos tais achados como uma evidência de que o “prêmio de governança corporativa” é reduzido (ou eliminado) pelo uso de derivativos, quando o mercado brasileiro acredita que esses instrumentos são utilizados para especulação ou benefício dos gestores.

This study investigates the influence of corporate governance on the relationship between financial derivatives usage and firm value in the Brazilian context. We use longitudinal data from 241 publicly-traded companies over the period of 2006 to 2017. Firms are divided into two groups: with better governance (listed in the premium segments of B3 - Level 1, Level 2 and New Market); and with worse governance (listed in the Traditional segment of B3). When potential endogeneity problems are mitigated by the System Generalized Method of Moments, the results indicate that the use of swaps reduces the value of well-governed firms that are less leveraged. We interpret these findings as evidence that the “corporate governance premium” is reduced (or eliminated) by derivatives usage, when the Brazilian market believes that these instruments are used for speculation or benefit of managers.

Este estudio investiga la influencia del gobernanza corporativa en la relación entre el uso de derivados financieros y el valor de la empresa en el contexto brasileño. Utilizamos datos longitudinales de 241 empresas que cotizaron en la bolsa durante el período de 2006 a 2017. Las empresas se dividen en dos grupos: con mejor gobernanza (cotizado en los segmentos premium de B3 - Nivel 1, Nivel 2 y Nuevo Mercado); y con peor gobernanza (cotizado en el segmento Tradicional). Cuando los problemas potenciales de endogeneidad son mitigados por el Método de Momentos Generalizados del Sistema, los resultados indican que el uso de swaps reduce el valor de las empresas bien gobernadas que stán menos endeudadas. Interpretamos estos hallazgos como evidencia de que la “prima de gobernanza corporativa” se reduce (o elimina) por el uso de derivados, cuando el mercado brasileño cree que estos instrumentos se utilizan para la especulación o beneficio de los administradores.

Abstract Cholesterol is a lipid molecule of great biological importance to animal cells. Dysregulation of cholesterol metabolism leads to raised blood total cholesterol levels, a clinical condition called hypercholesterolemia. Evidence has shown that hypercholesterolemia is associated with the development of liver and heart disease. One of the mechanisms underlying heart and liver alterations induced by hypercholesterolemia is oxidative stress. In this regard, in several experimental studies, gold nanoparticles (AuNP) displayed antioxidant properties. We hypothesized that hypercholesterolemia causes redox system imbalance in the liver and cardiac tissues, and AuNP treatment could ameliorate it. Young adult male Swiss mice fed a regular rodent diet or a high cholesterol diet for eight weeks and concomitantly treated with AuNP (2.5 μg/kg) or vehicle by oral gavage. Hypercholesterolemia increased the nitrite concentration and glutathione (GSH) levels and decreased the liver’s superoxide dismutase (SOD) activity. Also, hypercholesterolemia significantly enhanced the reactive oxygen species (ROS) and GSH levels in cardiac tissue. Notably, AuNP promoted the redox system homeostasis, increasing the SOD activity in hepatic tissue and reducing ROS levels in cardiac tissue. Overall, our data showed that hypercholesterolemia triggered oxidative stress in mice’s liver and heart, which was partially prevented by AuNP treatment.

RESUMO A lagarta-parda do eucalipto, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), vem sendo relatada de forma significativa em povoamentos florestais. A importância econômica de Thyrinteina arnobia para o setor florestal na atualidade evidencia a necessidade da consolidação do Manejo Integrado de Pragas Florestais (MIP Floresta), incluindo métodos de monitoramento e controle através de semioquímicos, como o emprego de feromônios. Os compostos químicos voláteis (COVs) em substâncias cuticulares de insetos podem contribuir na regulação da interação entre os indivíduos, sendo objeto de estudo da ecologia química. Dessa forma, objetivou-se realizar uma prospecção dos compostos orgânicos voláteis (COVs) cuticulares em Thyrinteina arnobia e avaliar o papel desses compostos como possíveis feromônios de curta distância. Para o estudo químico de substâncias feromonais, foi realizada a extração de compostos cuticulares (asas e pernas) em Thyrinteina arnobia de machos e fêmeas. Os extratos obtidos foram analisados por cromatografia gasosa com detector de ionização de chamas (GC-FID). Foi realizado um espectro de ação por meio da eletroantenografia acoplada à cromatografia gasosa (CG-EAG) dos extratos de asas e pernas de fêmeas virgens sobre a antena de machos de Thyrinteina arnobia. Contudo, não foi possível observar diferença significativa nas respostas das antenas de machos a nenhum dos estímulos oferecidos. Assim, é possível inferir que Thyrinteina arnobia não faz uso de compostos cuticulares para reconhecimento a curta distância, sendo necessários estudos complementares de comportamento sexual, incluindo observação de corte e cópula.

ABSTRACT The eucalyptus brown caterpillar, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), has been significantly reported in forest stands. The economic importance of Thyrinteina arnobia for the forestry sector today highlights the need to consolidate the Forest Integrated Pest Management (Forest IPM), including methods of monitoring and control through the use of semiochemicals, such as pheromones. Volatile chemical compounds (VOCs) in cuticular substances from insects, may contribute to the regulation in interaction between individuals, as object of study for chemical ecology. Thus, it was aimed the prospection for cuticular volatile organic compounds (VOCs) in Thyrinteina arnobia and the evaluation of the role of these compounds as possible short-distance pheromones for the species. For the study of pheromone chemical substances, cuticular compounds were extracted from wings and legs of Thyrinteina arnobia.The selected extracts were analyzed by gas chromatography with flame ionization detector (GC-FID). An action spectrum was carried out by electroantenography coupled to gas chromatography (GC-EAG) of wings and legs extracts from virgin female upon Thyrinteina arnobia male antenna, however, it was not possible to observe significant differences at the responses of the male antennae to any of the offered stimuli. Therefore, it is possible to infer that Thyrinteina arnobia does not use cuticular compounds for short distance recognition, thus complementary studies of sexual behavior, including observation of courtship and copulation are needed.

We have optimized the experimental conditions for the silver(I)-promoted oxidative coupling of methyl p-coumarate (I) and methyl ferulate (II), which is the most frequently used methodology to synthesize the bioactive dihydrobenzofuran neolignans 1 ((±)-trans-dehydrodicoumarate dimethyl ester) and 2 ((±)-trans-dehydrodiferulate dimethyl ester). Most of the tested conditions affected the conversion (i.e., the consumption of I and II) and the selectivity (i.e., the percentage of I and II that was converted into 1 and 2, respectively), so the optimized conditions were the ones that afforded the best balance between conversion and selectivity. Silver(I) oxide (0.5 equiv.) is the most efficient oxidant agent amongst the silver(I) reagents that were tested to convert methyl esters I and II into compounds 1 and 2, respectively. Acetonitrile, which has not yet been reported as a solvent for this reaction, provided the best balance between conversion and selectivity, besides being “greener” than other solvents that are more often employed (e.g., dichloromethane and benzene). Under the optimized conditions, the reaction time decreased from 20 to 4 h without significantly impacting the conversion and selectivity.

Abstract The incidence of aflatoxins and ochratoxin A in spices purchased from São Paulo State, Brazil was investigated. A total of 180 black pepper (Piper nigrum L.), colorífico (mixture of cornmeal or cassava flour with powdered annatto, Bixa orellana) ginger (Zingiber officinale Roscoe), nutmeg (Myristica fragrans), paprika (Capsicum annuum L.), and turmeric (Curcuma longa) were analyzed with a modified methods by using immunoaffinity column for clean-up and liquid chromatography/fluorescence detector for separation and quantification. Analytical methods were optimized for each spice, focusing mainly on the extraction step. OTA recoveries ranged from 65-102%. AFs recoveries were >70% except for AFG2. The average levels of AFs and OTA in black pepper, colorífico and turmeric samples were less than 2 ng/g. Twenty-five ginger samples (100%) contained OTA 0.10 - 7.10 ng/g and 21 samples (84%) contained AFs 0.10 - 9.55 ng/g. Twenty-nine nutmeg samples (100%) contained OTA 0.92 - 65.49 ng/g and AFs 2.71 - 48.67 ng/g. Thirty paprika samples (100%) contained OTA, 0.75 - 147.18 ng/g and twenty-two samples (73%) contained AFs, 0.11 - 14.92 ng/g. AFs and OTA in nutmeg and paprika could represent a food safety issue in Brazil.

ABSTRACT Purpose: to verify the impact of weight and BMI (Body Mass Index) changes on auditory and vocal symptoms in university professors, during the COVID-19 pandemic. Methods: the symptoms were assessed with a semi-structured questionnaire developed on Google Forms, to which the consent form was appended. It comprised 27 questions related to symptoms, changes, and health, during the pandemic - specifically, vocal and auditory symptoms, anthropometric factors, vocal parameters, physical activity, neck pain, and comorbidities. The Mann-Whitney and Chi-square test were used to identify differences or associations between variables (95% CI; P < 0.05). Results: altogether, 74 professors who comprise the faculty of the undergraduate program at the institution where the research was conducted were assessed. Significant differences were found between those with auditory symptoms (G1: worsened hearing; G2: unchanged hearing) regarding BMI, in which G1 had higher values; and sleep, in which G1 slept fewer hours. The chi-square test showed an association between the groups and BMI classification - those with worsened hearing (G1) were more overweight and their sleeping hours were more affected. There was also an association between the groups and voice change, headphone use (mainly in-ear) during classes, dizziness or vertigo episodes, tinnitus episodes and headache. Conclusion:this study revealed an association between worsened hearing, sleep, and BMI in university professors due to remote and distance teaching during the COVID-19 pandemic.

RESUMO Um dos fatores que podem afetar e limitar a produção nas lavouras de eucalipto é o ataque de insetos desfolhadores. Dentre essas, a lagarta marrom do eucalipto, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), destaca-se por ser a principal praga desfolhadora de Eucalyptus spp. no Brasil. Assim, o presente estudo teve como objetivo investigar o consumo alimentar de T. arnobia, em seu hospedeiro nativo, a goiaba (Psidium guajava L.) e em diferentes clones de E. urograndis (VE 41, I 144, TP 361 e VCC 865). Para a avaliação do consumo alimentar de T. arnobia, foram realizados testes de escolha e não escolha utilizando o hospedeiro nativo e o exótico, isoladamente ou em combinação. Nos testes sem chance de escolha, foi observado maior consumo para o clone VE 41 e para o hospedeiro nativo goiaba. A avaliação do consumo alimentar em testes de escolha não indicou preferência alimentar de T. arnobia entre a goiaba e os clones de E. urograndis, com exceção do clone TP 361, que foi significativamente menos consumido do que a goiaba. Em testes de escolha entre os diferentes clones de E. urograndis, o clone I 144 apresentou tendência a menor preferência alimentar, sendo consumido somente após 48 horas. Além disso, o consumo de folhas foi semelhante entre os clones VE 41, I1 14 e VCC 865. Em testes de escolha usando os clones de E. urograndis em pares, o clone VE 41 foi mais consumido enquanto o clone I 144 foi menos consumido quando comparado ao clone TP 361. Os resultados obtidos fornecem informações básicas para a indicação de clones de eucalipto e entendimento da interação e relações ecológicas, auxiliando no desenvolvimento de programas de Manejo Integrado de Pragas Florestais (MIP Florestal) para o controle de T. arnobia.

ABSTRACT One of the factors that may affect and limit the production in eucalypt plantations is the attack of defoliating insects. Among those, the brown eucalypt caterpillar, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), stands out for being the major defoliating pest of Eucalyptus spp. in Brazil. Thus, the present study aimed to investigate the food consumption of T. arnobia, in its native host, guava (Psidium guajava L.), and in the different E. urograndis clones (VE 41, I 144, TP 361 and VCC 865). To assess T. arnobia food consumption, choice and non-choice tests were carried out using the native and the exotic host, alone or in combination. In non-choice tests, it was observed a higher consumption for the VE 41 clone and the native host (guava). The food consumption evaluation in choice tests indicated no food preference of T. arnobia between guava and E. urograndis clones, with the exception for the TP 361 clone, which was significantly less consumed than guava. In choice tests between the different E. urograndis clones, the clone I 144 presented a tendency towards lower food preference, being consumed only after 48 hours. In addition, the leaf consumption was similar between the VE 41, I1 14 e VCC 865 clones. In choice tests using the E. urograndis clones in pairs, the VE 41 clone was more consumed while the I 144 clone was less consumed when compared to the TP 361 clone. The obtained results provide basic information for the indication of eucalypt clones, and the understanding of the interaction and ecological relationships, assisting in the development of Forest Integrated Pest Management (Forest IPM) programs for the control of T. arnobia.

Resumo: Introdução: Considerando um currículo integrado e orientado por competência dialógica de acordo com o exposto nas Diretrizes Curriculares Nacionais, a Unidade Educacional Sistematizada (UES) e a Unidade de Prática Profissional (UPP) compõem o currículo de um curso de Medicina de um município do interior paulista. Utilizam-se a Aprendizagem Baseada em Problemas (ABP) na UES e a problematização na UPP como metodologias de ensino, com o objetivo de buscar uma organização que conduza a uma formação coerente com o setor de saúde pública e o cenário de educação nacional. A UES é o foco deste estudo, pois notamos que há divergências entre os docentes sobre o papel do tutor. Com base nisso, a metodologia de ensino vigente na Faculdade de Medicina de Marília (Famema) nos levou aos seguintes questionamentos: “O professor se considera capacitado para atuar no método ABP?” e “De que forma as avaliações contribuem com o processo de ensino-aprendizagem?”. Assim, este trabalho teve por objetivo analisar a compreensão do docente acerca de sua capacitação para atuar na ABP e da pertinência das avaliações no processo ensino-aprendizagem na UES. Método: Trata-se de estudo do tipo exploratório-descritivo com abordagem de natureza qualitativa. A coleta de dados se deu pela realização de entrevista semiestruturada com professores que desenvolvem atividades na UES do primeiro ao quarto ano do curso de Medicina, selecionaram-se os participantes a partir de uma amostra não probabilística de intenção, totalizando 16 professores, sendo quatro de cada um dos quatro primeiros anos do curso.No exame dos dados, adotou-se a análise de conteúdo na modalidade temática que permitiu a definição de dois eixos temáticos: desafios para a formação docente e potencialidades e limites do processo de avaliação instituído. Resultados: A trajetória da ABP no processo de ensino-aprendizagem sob a ótica dos docentes nos mostrou uma variedade de compreensões. Em relação à formação docente, identificaram-se fragilidades no desenvolvimento do processo tutorial. Além disso, constatou-se que as estratégias utilizadas para a capacitação precisam ser revistas quanto à implementação e à inserção dos profissionais nelas. Observou-se que os docentes demonstram dificuldades em realizar uma avaliação dos estudantes integrando as dimensões afetivas, cognitivas e psicomotoras. Conclusão: Assim, independentemente do tempo de implementação do currículo, a educação permanente deve se constituir como espaço potente para a capacitação docente e a gestão do processo.

Abstract: Introduction: Considering an integrated curriculum that is guided by dialogical competence according to the National Curriculum Guidelines, the Systematized Educational Unit (UES) and the Professional Practice Unit (UPP) constitutes the curriculum of a medical course in a municipality in the countryside of the state of São Paulo, Brazil. Problem-Based Learning (PBL) is used in the UES and the problematization is used in the Professional Practice Unit as teaching methodologies, seeking an organization that leads to a training that is coherent with the public health sector and the national education scenario. The UES is the focus of this study because we observed that there are divergences among teachers regarding their role as tutors. Thus, we observed that the teaching methodology currently employed at Famema led us to some questions: Do the teachers consider themselves qualified to work with the PBL method? How do evaluations contribute to the teaching-learning process? Thus, this study aimed to analyze the teachers’ understanding of their ability to work with the PBL and the relevance of evaluations for the teaching-learning process in the UES. Method: This is an exploratory-descriptive study with a qualitative approach. Data collection was carried out using a semi-structured interview with teachers who work with the 1st to 4th years in the UES of the medical course, and the selection of the participants was carried out from a non-probabilistic sample of intention, totaling 16 teachers, including four teachers of each of the first four years of the course. The analysis of the data was performed by Content Analysis in the thematic modality, which allowed the definition of two thematic axes: Challenges for teacher training and Potentials and limits of the implemented evaluation process. Results: The trajectory of the PBL in the teaching-learning process from the point of view of teachers showed us a variety of understandings. As for teacher training, weaknesses were identified in the development of the tutoring process, and that the strategies used for training need to be reviewed regarding their implementation and the inclusion of the professionals into the process. Regarding the evaluation, it was observed that the teachers demonstrate difficulties in carrying out an evaluation of the students while integrating the affective, cognitive and psychomotor dimensions. Conclusion: Therefore, regardless the time of the curriculum implementation, Permanent Education should constitute a powerful space for teacher training and process management.

RESUMO Objetivo Avaliar os efeitos do estresse oxidativo sobre a sinalização da insulina em tecido cardíaco de camundongos obesos. Métodos Utilizaram-se 30 camundongos Swiss subdivididos igualmente (n=10) em três grupos: Grupo Controle, Grupo Obeso e Grupo Obeso Tratado com N-acetilcisteína. Após estabelecidas a obesidade e a resistência à insulina, os camundongos obesos foram tratados diariamente, durante 15 dias, via gavagem oral, com N-acetilcisteína na dose de 50mg/kg. Resultados Observaram-se maiores níveis de glicose sanguínea, conteúdos de nitrito e carbonil, e menores níveis proteicos de glutationa peroxidase e proteína quinase B fosforilada no Grupo Obeso quando comparado a seu respectivo controle. Por outro lado, o tratamento com N-acetilcisteína se mostrou eficiente em diminuir os níveis glicêmicos, os conteúdos de nitrito e carbonil, e aumentar significativamente os níveis proteicos de glutationa peroxidase e proteína quinase B fosforilada, quando comparados ao Grupo Obeso. Conclusão Obesidade e/ou dieta hiperlipídica levam a estresse oxidativo e à resistência à insulina no tecido cardíaco de camundongos obesos, e o uso da N-acetilcisteína como estratégia metodológica e terapêutica sugeriu haver relação entre ambos.

ABSTRACT Objective To evaluate the effects of oxidative stress on insulin signaling in cardiac tissue of obese mice. Methods Thirty Swiss mice were equally divided (n=10) into three groups: Control Group, Obese Group, and Obese Group Treated with N-acetylcysteine. After obesity and insulin resistance were established, the obese mice were treated with N-acetylcysteine at a dose of 50mg/kg daily for 15 days via oral gavage. Results Higher blood glucose levels and nitrite and carbonyl contents, and lower protein levels of glutathione peroxidase and phosphorylated protein kinase B were observed in the obese group when compared with their respective control. On the other hand, treatment with N-acetylcysteine was effective in reducing blood glucose levels and nitrite and carbonyl contents, and significantly increased protein levels of glutathione peroxidase and phosphorylated protein kinase B compared to the Obese Group. Conclusion Obesity and/or a high-lipid diet may result in oxidative stress and insulin resistance in the heart tissue of obese mice, and the use of N-acetylcysteine as a methodological and therapeutic strategy suggested there is a relation between them.

ABSTRACT Propolis, is a bee product collected from exudates and flower buds of several plants, has strong aroma and several biological applications. This study aimed at evaluating the chemical composition and in vitro antioxidant, antibacterial and cytotoxic properties of volatile oil from Brazilian brown propolis. It was extracted by hydrodistillation and analyzed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. Volatile oil from brown propolis exhibited strong antibacterial activity against H. pylori (MIC 3.25 µg/ml), Mycobacterium tuberculosis (MIC 50 µg/ml) and M. avium (MIC 62.5 µg/ml). It was evaluated in vitro for antioxidant activity by DPPH (IC50 25.0 µg/ml) and ABTS (IC50 30.1 µg/ml) methods. Its cytotoxic property was evaluated in normal (human fibroblasts, GM07429A) and tumor (MCF-7-human breast adenocarcinoma; HeLa-human cervical adenocarcinoma and M059J-human glioblastoma) cell lines. IC50 values were 81.32 µg/ml for GM07429A and 85.00, 129.40 and 84.12 µg/ml for MCF-7, HeLa and M059J cells, respectively. Three major dereplicated components of volatile oil from brown propolis were acetophenone (15.2%), nerolidol (13.3%), and spathulenol (11.6%). Our results contribute to a better understanding of the chemical and biological properties of Brazilian brown propolis and provide evidence for its potential medicinal use.

Abstract Colloidal silica is an important biocompatible, inert and non-toxic material for imaging, therapy, and drug delivery biomedical applications. In this context, the evaluation of colloidal suspensions and their stabilities by a Fiber Optic Quasi-Elastic Light Scattering sensor is proposed. Two different silica nanoparticles were prepared and characterized by scanning electron microscopy and X-ray diffraction, being completely amorphous, with mean diameters of 125 and 159 nm and average specific weight of 1.94 g.cm-3. The nanoparticles were dispersed in deionized water in different concentrations ranging from 0 to 2% (m/m), resulting in suspensions with mean kinematic viscosity of 0.009157 cm².s-1. The sensor showed different sensitivities regarding concentrations and diameters, with an increase in the light intensity dispersion caused by the scattering. A decreasing tendency of the decay rate of the autocorrelation function of the light intensity signal was verified with the variation of pH, and this decay rate also showed an abrupt decrease with the enhancement of the ionic strength, detecting the limits of the colloidal stability. This work presents a simple and reliable methodology for the colloidal assessment in a low-cost and minimally invasive way, easily extendable for different chemical and biological systems.

Duplex stainless steels (DSS) are corrosion resistant alloys largely used in chemical and petrochemical industries. Some commercial DSS contain 0.5-1.0% copper addition to improve the corrosion resistance by reducing the corrosion rate in non-oxidizing environments. Higher copper addition (≥ 2%) can also hard by precipitation, especially when fine copper precipitates (ε phase) are produced. In this work, a cast copper alloyed DSS type ASTM A890 grade 1B with 3.01%Cu was investigated. Different levels of hardness were produced by solution treatment and aging at 450, 500, 550 and 600 oC for periods of time up to 1 hour. The corrosion resistance of aged DSS was evaluated by electrochemical tests in three media: 0.6 mol/L NaCl, 0.3 mol/L H2SO4 and 0.6 mol/L NaCl + 0.3 mol/L H2SO4 solutions. The results indicate that the effect of Cu addition depends on the media studied. Polarization studies in 0.6 mol/L NaCl showed a small anodic current peak occurred at around 400 mV vs. Ag/AgCl, with a strong influence on the passive film stability. Additionally, chronoamperometric measurements at 400 mV vs. Ag/AgCl showed a high electrochemical activity for the samples in 0.6 mol/L NaCl.