In 2019, large amounts of oil reached the northeast coast of Brazil, causing damage to the environment and the local economy, especially in the state of Pernambuco. In order to correlate with possible sources, investigation was made of the geochemical biomarkers of the oils using “gold standard” forensic protocols from the European Committee for Standardization (CEN). The biomarkers study was improved by using gas chromatography-tandem mass spectrometry (GC-MS/MS), rather than the standard protocol that suggests use of the selected ion monitoring (SIM) method. Analysis was made of thirteen oil samples from the Pernambuco coast, in order to identify their degrees of similarity and the possible presence of oils from unreported spills. The use of eighteen diagnostic ratios and multivariate analysis revealed a cluster formed by eleven samples with biomarker distributions typical of oil from the 2019 spill. However, two samples had anomalous fingerprints, especially due to the absence of the 18α(H)-oleanane and 18β(H)-oleanane isomers. Both the CEN protocol applied for the classical biomarkers and a comprehensive Fourier transform mass spectrometry (FT-MS) analysis of polar compounds confirmed the dissimilarities between the samples. The findings suggested that these two oils could have originated from an event unrelated to the mysterious 2019 spill.

The Ipojuca River is considered the third most polluted river in Brazil due to the intense anthropogenic activities in the surrounding urban areas. The most important effluent is sewage discharge, which is responsible for considerable contamination. Traditional analyses (infrared spectroscopy, organic matter (OM), elemental analysis and granulometry) and advanced analysis of sterols by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were applied to evaluate the levels of urban contamination from sewage in 10 surface sediment samples from the Ipojuca River, in a stretch located in the Caruaru city, Pernambuco, Brazil. The results pointed to sandy sediments, rich in OM from anthropogenic sources (predominant). Eight different sterols were detected with a total concentration in a range between < limit of quantification (LOQ) and 1,634.4 µg g−1. Coprostanol (fecal biomarker) was detected in high concentrations (557.3 µg g−1) in the sediment collected close to an open-air market (considered the largest in the world), making it the most contaminated in the region. Multivariate statistical analysis revealed areas tending towards contamination and that 90% of sediments were contaminated by sewage. These results can be considered useful for preventive and remedial actions toward promoting human health in this region.

RESUMEN La toxina iota (ITX) es una enterotoxina binaria producida como protoxina por Clostridium perfringens (C. perfringens) tipo E que es activada por enzimas proteolíticas en el intestino delgado de los animales infectados. Mediante la despolimerización de los filamentos de actina, la ITX provoca la desorganización del citoesqueleto de las células promoviendo el aumento de la permeabilidad celular. Aquí, realizamos esta revisión con el objetivo de avanzar en la comprensión de las enfermedades entéricas clostridiales causadas por las toxinas de C. perfringens y la especificidad de ITX en las lesiones de la mucosa intestinal. La ITX consta de un componente enzimático (Ia) y un componente de unión (Ib). Examinamos los hallazgos histológicos recientemente publicados sobre los efectos de la ITX y su relación con las enfermedades entéricas intestinales. Histológicamente, se ha observado necrosis hemorrágica y hemorragia multifocal en la mucosa del yeyuno-ileo, el intestino delgado y el abomaso. Aunque el diagnóstico sigue basándose en la presencia de toxinas en el contenido intestinal y en la historia clínica y/o histológica, es importante desarrollar nuevos indicadores enterotóxicos capaces de establecer métodos precisos para diferenciar las acciones de la ITX y de otras toxinas implicadas en el proceso infeccioso de C. perfringens tipo E.

ABSTRACT The iota toxin (ITX) is a binary enterotoxin produced as a protoxin by Clostridium perfringens (C. perfringens) type E that is activated by proteolytic enzymes in the small intestine of infected animals. By depolymerization of the actin filaments, ITX causes cytoskeleton disorganization of cells promoting the increase of the cell permeability. Here, we conducted this review aiming to advance the understanding of enteric clostridial diseases caused by C. perfringens toxins and the specificity of ITX in the intestinal mucosa lesions. ITX consists of an enzymatic component (Ia) and a binding component (Ib). We screened the recently published histological findings of the ITX effects and its relationship with intestinal enteric diseases. Histologically, hemorrhagic necrosis and multifocal hemorrhage have been observed in the jejunum-ileum mucosa, the small intestine, and the abomasum. Although the diagnosis is still based on the presence of toxins in the intestinal contents and the clinical and/or histological history, it is important to develop novel enterotoxemic indicators capable of establishing precise methods for differentiate the actions of ITX and other toxins involved in the infectious process of C. perfringens type E.

This work describes the development of an automatic titrometric method in flow-batch with potentiometric detection using alternative and easily accessible materials. Arduino board and its modules, solenoid valves to control the flow rate, peristaltic pump to propel and suction fluids and tubes of inert material to connect the different parts of the Flow-Batch Analyser (FBA) were used. The use of solenoid valves controlled by microcontrollers proved to be efficient for controlling the flow in FBA systems, the correlations of their flow rates as a function of time showed good linearity with correlation coefficients (r) 0.9994 and 0.9997 for the valve 1 and valve 2, respectively, allowing correct addition of pre-established volumes. Accuracy was verified by comparing the results of the proposed method with the classic potentiometric titration with statistically evaluated by Student’s t-test in NaOH with HCl and vinegar with NaOH titrations. Results confirmed the efficiency to use Arduino board and its modules and automatic titrometric method in flow-batch developed in this work allow the implementation of practical disciplines, such as potentiometric titration and flow analysis system in undergraduate courses, making these instruments more accessible, especially for the chemistry students.

ABSTRACT Hepatitis A virus (HAV) infection has been considered one of the leading causes of acute hepatitis. The aim of the present study was to estimate the prevalence of HAV among children and adolescents in a population-based study in the capitals of the States of the North, Southeast and South of Brazil and identify predictive factors for the infection. A multi-stage sampling was used to select subjects aged between 5-9 and 10-19 years. Individual and household levels aside from the level of variables in the areas were collected. The outcome was the total IgG antibodies to HAV levels detected using a commercial Enzyme Immuno Assay (EIA). The associations between HAV and the independent variables were assessed using the odds ratio. A multilevel analysis was performed by GLLAMM using the Stata software. The prevalence of HAV infection in the 5-9 and 10-19 age groups was 28.7% and 67.5%, respectively for the North, 20.6% and 37.7%, for the Southeast and 18.9% and 34.5% for the South Region. The prevalence of HAV increased according to age in all sites. Variables related to education at the individual level (North and South), family and area level (South and Southeast) and family income level (Southeast and South) were independently associated with HAV infection. This emphasizes the need for individualized strategies to prevent the infection.

ABSTRACT Background: People living with HIV (PLH) under combined antiretroviral therapy (cART) are at risk of developing type 2 diabetes mellitus (T2DM). Objective: We examined the incidence of T2DM, associated factors and mean time to outcome in PLH under cART. Method: Data for this multicenter cohort study were obtained from PLH aged over 18, who started cART in 13 Brazilian sites from 2003 to 2013. Factors associated with incident T2DM were evaluated by Cox multiple regression models. Results: A total of 6724 patients (30,997.93 person-years) were followed from January 2003 to December 2016. A T2DM incidence rate of 17.3/1000 person-years (95%CI 15.8-18.8) was observed. Incidence of isolated hypertriglyceridemia and impaired fasting glucose (IFG) were 84.3 (95%CI 81.1-87.6) and 14.5/1000 person-years (95%CI 13.2-15.9), respectively. Mean time to T2DM onset was 10.5 years (95%CI 10.3-10.6). Variables associated with incident T2DM were age 40-50 [Hazard Ratio (HR) 1.7, 95%CI 1.4-2.1] and ≥ 50 years (HR 2.4, 95%CI 1.9-3.1); obesity (HR 2.1, 95%CI 1.6-2.8); abnormal triglyceride/HDL-cholesterol ratio (HR 1.8, 95%CI 1.51-2.2). IFG predicted T2DM (HR 2.6, 95%CI 1.7-2.5) and occurred on average 3.3 years before diabetes onset. Exposure to stavudine for ≥ 2 years was independently associated with incident T2DM [HR 1.6, 95%CI 1.0-2.2). Conclusion: Brazilian PLH under cART are at significant risk of developing T2DM and share risk factors for diabetes onset with the general population, such as older age, obesity, and having metabolic abnormalities at baseline. Moreover, stavudine use was independently associated with incident T2DM. Identifying PLH at a higher risk of T2DM can help caretakers trigger health promotion and establish specific targets for implementation of preventive measures.

RESUMO: Este estudo teve por objetivo caracterizar a prevalência, aspectos clínicos, macroscópicos e histopatológicos dos cães acometidos por neoplasmas testiculares, a partir dos espécimes de biópsias do Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV-UFSM) em 19 anos. Parâmetros quanto à idade, porte, raça dos cães acometidos também foram estabelecidos. De todos os cães com algum tipo de neoplasma submetido à análise histopatológica no LPV nesses 19 anos (n=1.900), 213 (11,2%) tinham ao menos um neoplasma testicular. Os tecidos de 190 cães (com 220 neoplasmas) estavam disponíveis para reavaliação histológica. Os cães deste estudo apresentaram diferentes tipos de neoplasmas testiculares com frequências relativamente semelhantes. Em ordem decrescente, os neoplasmas testiculares mais frequentes foram: seminomas (88/220), leydigomas (64/220), sertoliomas (61/220) e o tumor misto de células germinativas e do estroma do cordão sexual (MGSCT; 07/220). Dentre os cães com raça definida (119 casos), as raças de grande porte tiveram o maior número de casos (50/119), seguido das raças de pequeno (47/119) e médio porte (22/119). As idades dos cães acometidos por neoplasmas testiculares variaram de 10 meses a 18 anos. Aumento de volume testicular foi a manifestação clínica mais comum. Onze cães tinham informações sobre sinais clínicos sugestivos da síndrome da feminilização. Nos seminomas, houve o predomínio do padrão difuso sobre o intratubular. Dois locais (compartimentos luminal e basal) sugestivos de início das transformações neoplásicas nas células germinativas foram observados nos seminomas intratubulares, corroborando com a hipótese de que os seminomas caninos possivelmente tem patogênese semelhante à observada nos seminomas espermatocíticos humanos. Sertoliomas e leydigomas foram neoplasmas com alta variação na morfologia celular. Os sertoliomas tinham células neoplásicas dispostas em cinco arranjos histológicos distintos. Quanto aos leydigomas, os padrões histológicos sólido-difuso e cístico-vascular foram os mais comumente observados. Através deste estudo foi possível estabelecer alguns dos principais aspectos clínicos, macroscópicos e histopatológicos dos neoplasmas testiculares diagnosticados em 19 anos na área de abrangência do LPV-UFSM.

ABSTRACT: This study aimed to characterize the prevalence and clinical, macroscopic and histopathological aspects of dogs affected by testicular tumors based on biopsy specimens from the Laboratório de Patologia Veterinária of the Universidade Federal de Santa Maria (LPV-UFSM) over 19 years. Parameters regarding the age, size, and breed of the affected dogs were also established. Of all dogs with some type of neoplasm submitted to histopathological analysis at the LPV over these 19 years (n=1,900), 213 (11.2%) had at least one testicular neoplasm. The tissues of 190 dogs (with 220 neoplasms) were available for histological reassessment. The dogs in this study had different types of testicular tumors with relatively similar frequencies. In descending order, the most frequent testicular neoplasms were seminomas (88/220), Leydig (interstitial) cell tumor (LCT; 64/220), Sertoli cell tumor (SCT; 61/220), and mixed germ cell-sex cord stromal tumor (MGSCT) (07/220). Among the dogs of defined breed (119 cases), large breeds had the largest number of cases (50/119), followed by small (47/119) and medium-sized (22/119) breeds. The ages of dogs affected by testicular tumors ranged from 10 months to 18 years. Increased testicular volume was the most common clinical manifestation. Eleven dogs presented information about clinical signs suggestive of hyperestrogenism syndrome (feminization). In seminomas, the diffuse pattern predominated over the intratubular pattern. Two sites (luminal and basal compartments) suggestive of the onset of neoplastic transformations in germ cells were observed in intratubular seminomas. They corroborate the hypothesis that canine seminomas possibly have pathogenesis similar to that observed in human spermatocytic seminomas. The SCTs and LCTs presented high cell morphology variation. SCTs had neoplastic cells organized in five different histological arrangements. As for LCT, solid-diffuse and cystic-vascular histological patterns were the most commonly observed. Through this study, it was possible to establish some of the leading clinical, macroscopic, and histopathological aspects of testicular neoplasms diagnosed over 19 years in the area covered by the LPV-UFSM.

Resumo Este artigo analisa os fatores que influenciam os municípios em sua tomada de decisão sobre a prestação de serviços públicos de resíduos por meio de consórcios. Vários estudos abordaram essa questão pesquisando países ocidentais e desenvolvidos, mas há uma lacuna na literatura que explora o fenômeno em países em desenvolvimento como o Brasil. Este estudo, portanto, seleciona os governos locais no Brasil e analisa sua política de coleta e tratamento de resíduos, com foco na prestação de serviços públicos por meio de acordos cooperativos, particularmente consórcios intermunicipais. Os consórcios intermunicipais podem ser uma solução para os desafios políticos e gerenciais em torno do gerenciamento de resíduos sólidos e da prestação de outros serviços públicos. No entanto, ainda não está claro quais fatores influenciam os governos locais a adotar essa estratégia. O estudo utilizou uma abordagem transversal aplicada a uma amostra de 963 municípios e adotou a perspectiva da Ação Coletiva Institucional, identificando as características da comunidade, as características transacionais dos bens, e a estrutura das redes de política pública, que influenciam a tomada de decisão dos governos locais para cooperar. Os resultados têm implicações nas políticas públicas que adotam acordos de cooperação intermunicipais no Brasil.

Abstract This article analyzes the factors that affect local governments’ decision-making processes on whether to engage in cooperative agreements through intermunicipal consortia. Several studies have examined this issue in Western developed countries, but there is a gap in the literature regarding the phenomenon in the developing world. The research addresses this gap and observes the Brazilian local governments’ policies on waste services, focusing on cooperative agreements such as interlocal consortia. These arrangements may be a solution to the political and managerial challenges of providing public services in many areas, including waste collection, treatment, and disposal. However, it is still unclear what factors influence municipalities in their decision to cooperate. Based on cross-sectional research exploring 963 Brazilian municipalities and on the perspective of Institutional Collective Action, this study identified characteristics of communities, transaction characteristics of goods, and the structure of policy networks that influence the local governments in their decision to work cooperatively. The findings shed light on the field of public policies, particularly those carried out through intermunicipal consortia.

Resumen Este artículo analiza los factores que influyen en los municipios en su toma de decisiones sobre la prestación de servicios públicos de residuos por medio de consorcios. Varios estudios abordaron esa cuestión investigando países occidentales y desarrollados, pero existe una laguna en la literatura que explora el fenómeno en países en desarrollo como Brasil. Por lo tanto, este estudio selecciona los gobiernos locales de Brasil y analiza su política de recolección y tratamiento de residuos, con foco en la prestación de servicios públicos a través de acuerdos cooperativos, particularmente, consorcios intermunicipales. Estos pueden ser una solución para los desafíos políticos y gerenciales relacionados con la gestión de residuos sólidos y la prestación de otros servicios públicos. No obstante, aún no está claro qué factores influyen en los gobiernos locales para adoptar esa estrategia. El estudio utilizó un enfoque transversal aplicado a una muestra de 963 municipios y adoptó la perspectiva de la acción colectiva institucional, identificando las características de la comunidad, las características transaccionales de los bienes, y la estructura de las redes de políticas públicas, que influyen en la toma de decisiones de los gobiernos locales para cooperar. Los resultados tienen implicaciones en las políticas públicas que adoptan acuerdos de cooperación intermunicipales en Brasil.

A series of functionalized 1,1,1-trihalo-4-methoxy-3-alken-2-ones [CX3C(O)CR1=CROMe, where X = F or Cl; R = n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-tridecyl, (CH2)2CH=C(Me)2, (CH2)2Ph, (CH2)2-(4-HOC6H4), (CH2)2-(4-MeOC6H4), (CH2)2CO2Me, (CH2)3CO2Me, CH(SMe)CH3, CH2(2-MeOC6H4), and R1 = H, and R = H and R1 = n-decyl] were synthesized from respective alkyl methyl ketones or aldehyde via acetal acylation using trifluoroacetic anhydride and trichloroacetyl chloride. 1,1,1-Trihalo-4-methoxy-3-alken-2-ones with acid-compatible substituents were easily hydrolyzed to respective trihalomethyl-1,3-diketones. The 1,1,1-trihalo-4-methoxy-3-alken-2-ones and/or respective trihalomethyl-1,3-diketones were reacted regiospecifically with hydroxylamine hydrochloride, leading to isoxazole derivatives, and with hydrazines, leading to respective 1H-pyrazole derivatives. The structures of all compounds were assigned based on nuclear magnetic resonance (NMR) and mass spectrometric data. This method represents an efficient pathway for the regioselective trihaloacetylation of asymmetrically substituted alkyl methyl ketones and highly self-condensing aldehydes. Moreover, this approach allows the introduction of biologically recognizable moieties, such as those from levulinic acid, sulcatone (prenyl), benzylacetone, anisylacetone, and raspberry ketone, as synthetic molecular targets.

Resumo Mycoplasma suis é uma bactéria que causa a hemoplasmose em suínos. Este agente é capaz de se aderir à superfície dos eritrócitos de suínos, ocasionando deformações estruturais nestas células. No Brasil, poucos são os relatos acerca do parasita, da infecção e de seus impactos econômicos nas esferas produtiva e sanitária. O objetivo deste estudo foi investigar, por meio da PCR em tempo real quantitativa (qPCR) baseada no gene 16S rRNA, a ocorrência de M. suis em 64 amostras de sangue de suínos de criações extensivas dos municípios de Itapecuru Mirim, Santa Rita e Rosário, localizados no estado do Maranhão. Foram obtidos um percentual de 82,3%, 65,2% e 25% de amostras positivas na qPCR para M. suis nos municípios de Itapecuru Mirim, Santa Rita e Rosário, respectivamente. Este estudo mostra que M. suis circula entre os suínos de criações extensivas no estado do Maranhão.

Abstract Mycoplasma suis is a bacterium that causes hemoplasmosis in pigs. This agent is capable of adhering to the surface of porcine erythrocytes, inducing structural changes on these cells. In Brazil, there are few reports about the disease, its causal agent, and the economic impact of this pathogen on pig production systems and farm sanitation. The present study aimed to investigate the occurrence of M. suis in extensive swine farms located in the counties of Itapecuru Mirim, Santa Rita and Rosario, State of Maranhão, northeast Brazil. For such purpose, 64 blood samples of pigs from these facilities were tested for M. suis using a 16S rRNA gene-based quantitative real-time PCR (qPCR); 82.3%, 65.2% and 25% of blood samples of swine from farms in the cities of Itapecuru Mirim, Santa Rita and Rosario were positive for M. suis by qPCR, respectively. This study shows, for the first time, that M. suis circulates in pig populations from the state of Maranhão, Northeast Brazil.

RESUMO: Devido a alta prevalência dos mastocitomas cutâneos caninos (MCCs) na rotina diagnóstica, vários fatores, especialmente fatores prognósticos, têm sido buscados para auxiliar na determinação do comportamento biológico desse neoplasma. A imuno-histoquímica é uma das principais ferramentas empregadas para diferenciar tumores biologicamente mais agressivos de tumores menos agressivos. Entretanto, algumas imunomarcações sofrem influência pela fixação em formol, interferindo nos resultados. Este estudo compreendeu avaliar através de uma etapa retrospectiva e uma etapa prospectiva casos de MCCs diagnosticados na rotina laboratorial. Um total de 25 amostras, sem conhecimento do tempo de fixação, foi analisado no estudo retrospectivo e 12 amostras, com tempos de fixação conhecidos, no estudo prospectivo. Foram aplicados nos dois estudos, dois sistemas de graduação histológica (Patnaik e Kiupel), a coloração especial de azul de toluidina e a imuno-histoquímica para as proteínas KIT e Ki67. Adicionalmente, no estudo prospectivo, foram testados dois sistemas de amplificação (biotinilado e não biotinilado) para a proteína Ki67 e a técnica de AgNOR (contagem das regiões organizadoras nucleolares argirofílicas). Na etapa retrospectiva, observou-se uma maior concordância entre os patologistas avaliadores quando o sistema Kiupel foi utilizado. A imunomarcação para KIT se manteve eficaz em ambos os estudos, independentemente do tempo de fixação. A imunomarcação para o Ki67 mostrou-se altamente sensível ao tempo de fixação em formol, sendo observada falha na imunomarcação em 56% dos casos do estudo retrospectivo. No estudo prospectivo, constatou-se que amostras fixadas por mais de 24 horas em formol apresentaram redução na quantidade de células imunomarcadas (alterando a determinação da fração de crescimento celular) ou apresentaram ausência de imunomarcação em ambos os sistemas de amplificação. A utilização do método AgNOR, para avaliar a taxa de proliferação celular, pode ser uma alternativa quando o tempo de fixação do neoplasma for desconhecido ou superior a 24 horas.

ABSTRACT: Due to the high prevalence of mast cell tumors (MCTs) in the diagnostic routine, several factors, especially prognostic, have been sought to determine the biological behavior of these neoplasms. Immunohistochemistry (IHC) is one of the main tools utilized to biologically differentiate more aggressive tumors from less aggressive ones. However, some immunostainings are influenced by formalin fixation, interfering with the results. This is both a retrospective and prospective study of MCTs diagnosed in laboratory routine. A total of 25 samples, without knowledge about fixation time, were analyzed in the retrospective study, whereas 12 samples, with known fixation times, were assessed in the prospective study. Two histologic grading systems (Patnaik and Kiupel), special staining of toluidine blue, and IHC for KIT and Ki67 proteins were applied in both studies. Additionally, two amplification systems (biotinylated and non-biotinylated) for Ki67 protein and counting of the argyrophilic nucleolar organizing regions (AgNOR method) were tested in the prospective study. In the retrospective study, greater agreement between the evaluating pathologists was observed when the Kiupel system was used. IHC staining for KIT protein was effective in both studies, regardless of fixation time. IHC staining for Ki67 protein was highly sensitive to formaldehyde, and staining failure was observed in 56% of the cases in the retrospective study. In the prospective study, samples fixed for longer than 24 hours showed a reduction in the number of stained cells (altering the determination of the cell growth fraction) or showed absence of IHC staining in both amplification systems. The use of the AgNOR method to evaluate the rate of cell proliferation may be an alternative when the fixation time of the neoplasm is unknown or longer than 24 hours.

Abstract: The margay (Leopardus wiedii) is a small to medium sized Neotropical felid classified as Vulnerable in Brazil. The species’ northeastern range limits and use of open vegetation habitats has not been properly defined. The Caatinga biome is composed of a variable mosaic of semi-arid scrub/forest habitats and dominates the northeast region of Brazil. To date, it has not been confirmed that margays use the more open semi-arid thorny scrub habitat which is most characteristic of this region (the caatinga scrub). This study presents data from the first camera trap records for margays occurring in caatinga scrub, and documents new localities which constitute an extension of the species’ range in northeastern Brazil.

Resumen: El margay (Leopardus wiedii) es un felino de tamaño pequeño a mediano clasificado como vulnerable en Brasil. Los rangos de distribución nororiental de la especie y el uso de hábitat en ambientes abiertos no han sido bien definidos. El bioma Caatinga está compuesto por un mosaico de ambientes semiáridos arbustivos y forestales, los cuales dominan la región nororiente de Brasil. A la fecha no se ha confirmado el uso del hábitat semiárido abierto arbustivo espinoso que es característico de esta región (la caatinga propiamente dicha). Este estudio presenta los primeros registros de margay en cámaras trampa en la caatinga y documenta nuevas localidades que constituyen la ampliación del rango de distribución de esta especie en el nororiente brasileño.

The European pepper moth Duponcheliafovealis Zeller (Lepidoptera: Crambidae) is reported for the first time in South America, in the State of Paraná, Brazil. D.fovealis causes damage to strawberries and weakens the plants. Three natural enemies controlling D.fovealis were found and identified as Apanteles sp. (Hymenoptera: Braconidae), Hyaliodocoris insignis (Heteroptera: Miridae) and the entomopathogenic fungus Beauveria bassiana.

El primer reporte de Duponchelia fovealis Zeller (Lepidoptera:Crambidae) fue por daños a la fresa (Fragaria x ananassa) en América del Sur en el Estado del Paraná, Brasil. Se encontraron tres enemigos naturales para controlar D. fovealis identificados como Apanteles sp. (Hymenoptera: Braconidae), Hyaliodocoris insignis (Heteroptera: Miridae) y el hongo entomopatogenico Beauveria bassiana.

We herein report the synthesis of hybrid kauranoid molecules of type 1,2,3-triazole-1,4-disubstituted aiming to improve the antimalarial activity of kaurenoic and xylopic acids. The CuI-catalyzed cycloaddition of azides and kauranoid terminal alkynes was explored as a hybridization strategy. Kauranoid terminal alkynes were prepared from kaurenoic and xylopic acids that were isolated from Wedelia paludosa D. C. (Asteraceae) and Xylopia frutescens Aubl. (Annonaceae). A total of 15 kauranoid derivatives, including nine new triazoles, were obtained and five out of these were more active than the original diterpenes. Interestingly, an increased activity was observed for a kauranoid propargyl ether. Interaction between ent-kaurane diterpene derivatives and Ca2+-ATPase (PfATP6) was investigated. Synthesis of diterpene derivatives emerges as a possible route to be explored in the quest of potentially new inhibitors of PfATP6.

Plantas de coberturas são fundamentais para sustentabilidade do sistema de plantio direto em regiões tropicais. No entanto, ainda há pouca informação sobre os efeitos dessas plantas e da adubação nitrogenada sobre as frações da matéria orgânica do solo. O objetivo deste trabalho foi avaliar o efeito de plantas de cobertura com composição química diferenciada e da aplicação de N em cobertura nas frações lábeis e humificadas da matéria orgânica de um Latossolo sob plantio direto no Cerrado. O estudo foi realizado em delineamento de blocos ao acaso, com parcelas divididas e três repetições. Foram utilizadas quatro plantas de cobertura nas parcelas e presença ou ausência de fertilização nitrogenada em cobertura na subparcela. As seguintes plantas de cobertura foram utilizadas em sucessão ao milho, por oito anos: Urochloa ruziziensis ; Canavalia brasiliensis M. ex Benth; Cajanus cajan (L.) Millsp; e Sorghum bicolor (L.) Moench. Em geral, o uso da U. ruziziensis resultou nos maiores teores de C no solo com destaque para o C nas frações ácido húmico e C orgânico particulado, que são indicadores da qualidade da matéria orgânica do solo. O C das substâncias húmicas e o C orgânico associados aos minerais apresentaram as maiores proporções do C orgânico total e demonstraram a forte interação da matéria orgânica com os óxidos de Fe e Al e a caulinita, que predominam nesses solos intemperizados do Cerrado.

Cover plants are essential for the sustainability of no-tillage systems in tropical regions. However, information on the effects of these plants and N fertilization on soil organic matter fractions is still scarce. This study evaluated the effect of cover crops with different chemical composition and of N topdressing on the labile and humified organic matter fractions of an Oxisol of the Cerrado (savanna-like vegetation). The study in a randomized complete block design was arranged in split-plots with three replications. Four cover species were tested in the plots and the presence or absence of N topdressing in the subplot. The following cover species were planted in succession to corn for eight years: Urochloa ruziziensis; Canavalia brasiliensis M. ex Benth; Cajanus cajan (L.) Millsp; and Sorghum bicolor (L.) Moench. In general, the cultivation of U. ruziziensis increased soil C levels, particularly of C in the humic acid and particulate organic C fractions, which are quality indicators of soil organic matter. The C in humic substances and mineral organic C accounted for the highest proportions of total organic C, demonstrating the strong interaction between organic matter, Fe and Al oxides and kaolinite, which are predominant in these weathered soils of the Cerrado.