Hexanuclear and undecanuclear iron(III) carboxylates as catalyst precursors for cyclohexane oxidation

Two multinuclear complexes [Fe-6(mu(3)-O)(2)(mu(4)-O-2)L-10(OAc)(2)(H2O)(2)]center dot 2.625Et(2)O center dot 2.375H(2)O (1) and [(Fe11Cl)-Cl-III-(mu(4)-O)(3)(mu(3)-O)(5)L-16(dmf)(2.5)(H2O)(0.5)]center dot Et2O center dot 1.25dmf center dot 3.8H(2)O (2), where HL = 3,4,5-trimethoxybenzoic acid and dmf = dimethylformamide, have been prepared from trinuclear iron(III) carboxylates via their structural rearrangement in dimethylformamide or diethyl ether-dimethylformamide 9:1, respectively, and slow vapor diffusion of diethyl ether into the reaction mixture. Both compounds have been characterized by X-ray diffraction, optical, Mossbauer spectroscopy, and magnetic measurements. Complex 1 possesses a hexanuclear ferric peroxido-dioxido {Fe-6(O-2)(O)(2)}(12+) core unit, which adopts a recliner conformation, while complex 2 contains an unprecedented {Fe11O8Cl}(16+) core, in which 9 ferric ions are six-coordinate and the remaining two are five-coordinate. Another structural feature of note of the undecanuclear core is the presence of a deformed cubane entity {Fe-4(mu(3)-O)(mu(4)-O)(3)}(4+). Both complexes act as catalyst precursors for the oxidation of cyclohexane to cyclohexanol and cyclohexanone with aqueous H2O2, in the presence of pyrazinecarboxylic acid. Remarkable TONs and TOFs (the latter mainly for 1) with concomitant quite good yields have been achieved under mild conditions. Moreover, 1 exhibits remarkably high activity in an exceptionally short reaction time (45 min), being unprecedented for any metal catalyzed alkane oxidation by H2O2. The catalytic reactions proceed via Fenton type chemistry

Analysis of motor capacities in the maturational stages of female adolescents

Introduction: Maturation is a biological phenomenon inherent to the human being that acts alongside environmental factors in its relationship with the development of children and adolescents.Objective: To analyse the motor skills during maturational stages of female adolescents.Methods: This study included 133 female adolescents aged between 10 and 17 years from federal schools in the city of Rio Branco, State of Acre, Brazil. Sexual maturation was evaluated using Tanner’s self-assessment. Motor skills were assessed using the following tests: strength (Jump Test); coordination (Burpee Test); balance (Flamingo Test); flexibility (Sit and Reach Test); agility (Shuttle Run Test). The data were analysed using R software through analysis of variance. The significance level was fixed at 5%.Result: No significant statistical results were found for strength, agility, balance and flexibility, evidencing that maturational advances did not influence these skills. In the coordination variable, significant results were obtained.Conclusion: The results of this study suggest that maturational advancement in adolescents does not influence strength, agility, balance or flexibility. However, it does influence coordination, presenting better performance at stage P2.Introduction: Maturation is a biological phenomenon inherent to the human being that acts alongside environmental factors in its relationship with the development of children and adolescents.Objective: To analyse the motor skills during maturational stages of female adolescents.Methods: This study included 133 female adolescents aged between 10 and 17 years from federal schools in the city of Rio Branco, State of Acre, Brazil. Sexual maturation was evaluated using Tanner’s self-assessment. Motor skills were assessed using the following tests: strength (Jump Test); coordination (Burpee Test); balance (Flamingo Test); flexibility (Sit and Reach Test); agility (Shuttle Run Test). The data were analysed using R software through analysis of variance. The significance level was fixed at 5%.Result: No significant statistical results were found for strength, agility, balance and flexibility, evidencing that maturational advances did not influence these skills. In the coordination variable, significant results were obtained.Conclusion: The results of this study suggest that maturational advancement in adolescents does not influence strength, agility, balance or flexibility. However, it does influence coordination, presenting better performance at stage P2

Phosphorus–iron interaction in sediments : can an electrode minimize phosphorus release from sediments?

All restoration strategies to mitigate eutrophication depend on the success of phosphorus (P) removal from the water body. Therefore, the inputs from the watershed and from the enriched sediments, that were the sink of most P that has been discharged in the water body, should be controlled. In sediments, iron (hydr)oxides minerals are potent repositories of P and the release of P into the water column may occur upon dissolution of the iron (hydr)oxides mediated by iron reducing bacteria. Several species of these bacteria are also known as electroactive microorganisms and have been recently identified in lake sediments. This capacity of bacteria to transfer electrons to electrodes, producing electricity from the oxidation of organic matter, might play a role on P release in sediments. In the present work it is discussed the relationship between phosphorus and iron cycling as well as the application of an electrode to work as external electron acceptor in sediments, in order to prevent metal bound P dissolution under anoxic conditions.The authors are grateful to two anonymous reviewers of a previous version of the manuscript for the constructive comments and suggestions. The authors also acknowledge the Grant SFRH/BPD/80528/2011 from the Foundation for Science and Technology, Portugal, awarded to Gilberto Martins

Prevalência, fatores de risco e genótipos da hepatite C entre usuários de drogas

OBJECTIVE: To estimate prevalence of hepatitis C virus (HCV) infection and identify risk factors associated and circulating HCV genotypes and subtypes. METHODS: Study conducted including 691 drug users attending 26 charitable, private and public drug treatment centers in Goiânia and Campo Grande, central-western Brazil, between 2005 and 2006. Sociodemographic characteristics and risk factors for HCV infection were collected during interviews. Blood samples were tested for HCV antibodies (anti-HCV). Positive samples were submitted to HCV RNA detection by PCR with primers complementary to 5' NC and NS5B regions of viral genome and genotyped by line probe assay (LiPA) and direct nucleotide sequencing followed by phylogenetic analysis. The prevalence and odds ratio were calculated with 95% confidence intervals. Risk factors were first estimated in the univariate analysis (pOBJETIVO: Estimar la prevalencia y factores asociados a la infección por el virus de la hepatitis C en usuarios de drogas e identificar los genotipos y subtipos virales circulantes. MÉTODOS: Estudio realizado con 691 usuarios de drogas de 26 centros de tratamiento de uso de drogas filantrópicos, particulares y públicos de Goiania y Campo Grande (Centro-Oeste), entre 2005 y 2006. Datos sociodemográficos y factores de riesgo para infección por el HCV fueron obtenidos por medio de entrevistas. Muestras sanguíneas fueron evaluadas para la detección de anticuerpos para el HCV. Las muestras positivas fueron sometidas a la detección de RNA-HCV por la reacción en cadena de polimerasa con iniciadores complementarios a las regiones 5' NC y NS5B del genoma viral y genotipadas por el line probe assay (LiPA) y por secuenciación directa, seguido del análisis filogenético. Prevalencia y odds ratio fueron calculados con intervalo de 95% de confianza. Los factores de riesgo con pOBJETIVO: Estimar a prevalência e fatores associados à infecção pelo vírus da hepatite C em usuários de drogas e identificar os genótipos e subtipos virais circulantes. MÉTODOS: Estudo realizado com 691 usuários de drogas de 26 centros de tratamento de uso de drogas filantrópicos, particulares e públicos de Goiânia (GO) e Campo Grande (MS), entre 2005 e 2006. Dados sociodemográficos e fatores de risco para infecção pelo HCV foram obtidos por meio de entrevistas. Amostras sangüíneas foram testadas para a detecção de anticorpos para o HCV. As amostras positivas foram submetidas à detecção do RNA-HCV pela reação em cadeia da polimerase com iniciadores complementares às regiões 5' NC e NS5B do genoma viral e genotipadas pelo line probe assay (LiPA) e por seqüenciamento direto, seguido de análise filogenética. Prevalência e odds ratio foram calculados com intervalo de 95% de confiança. Os fatores de risco com

Abundance and Species Richness of Leafhoppers and Planthoppers (Hemiptera: Cicadellidae and Delphacidae) in Brazilian Maize Crops

Fil: De Oliveira, Charles Martins. Embrapa Cerrados. Planaltina. Brasília/DF; BrazilFil: De Oliveira, Elizabeth. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Prazeres De Souza, Isabel Regina. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Alves, Elcio. DuPont do Brazil S.A. DivisÆo Pioneer Sementes. Itumbiara/GO; BrazilFil: Dolezal, William. Pioneer Hi-Bred International. Itumbiara/GO; BrazilFil: Paradell, Susana Liria. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Marino de Remes Lenicov, Ana María. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Frizzas, Marina Regina. Universidade de Brasília. Departamento de Zoologia. Instituto de Ciências Biológicas. Brasília/DF; Brazi