Purple acid phosphatases (PAPs) are a group of metallohydrolases that contain a dinuclear Fe III M II center (M II = Fe, Mn, Zn) in the active site and are able to catalyze the hydrolysis of a variety of phosphoric acid esters. The dinuclearhas recently been prepared and is found to closely mimic the coordination environment of the Fe III Zn II active site found in red kidney bean PAP (Neves et al. J. Am. Chem. Soc. 2007, 129, 7486). The biomimetic shows significant catalytic activity in hydrolytic reactions. By using a variety of structural, spectroscopic, and computational techniques the electronic structure of the Fe III center of this biomimetic complex was determined. In the solid state the electronic ground state reflects the rhombically distorted Fe III N 2 O 4 octahedron with a dominant tetragonal compression aligned along the μ-OH-Fe-O phenolate direction. To probe the role of the Fe-O phenolate bond, the phenolate moiety was modified to contain electron-donating or -withdrawing groups (-CH 3 , -H, -Br, -NO 2 ) in the 5-position. The effects of the substituents on the electronic properties of the biomimetic complexes were studied with a range of experimental and computational techniques. This study establishes benchmarks against accurate crystallographic structural information using spectroscopic techniques that are not restricted to single crystals. Kinetic studies on the hydrolysis reaction revealed that the phosphodiesterase activity increases in the order -NO 2 rBr rH rCH 3 when 2,4-bis(dinitrophenyl)phosphate (2,4-bdnpp) was used as substrate, and a linear free energy relationship is found when log(k cat /k 0 ) is plotted against the Hammett parameter σ. However, nuclease activity measurements in the cleavage of double stranded DNA showed that the complexes containing the electron-withdrawing -NO 2 and electron-donating -CH 3 groups are the most active while the cytotoxic activity of the biomimetics on leukemia and lung tumoral cells is highest for complexes with electron-donating groups.

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Dietary patterns before pregnancy may be associated with depressive symptomatology during pregnancy. The aim of this study was to identify dietary patterns before pregnancy and to examine the association between these dietary patterns and depressive symptoms during pregnancy. A prospective cohort of 248 healthy pregnant women were followed at 5-13, 20-26, and 30-36 gestational weeks. Dietary intake was obtained by using a food-frequency questionnaire administered between 5 and 13 gestational weeks, which referred to the 6 mo preceding gestation, and factor analysis (principal components) was applied to identify dietary patterns. The Edinburgh Postnatal Depressive Scale (EPDS) was used to evaluate depressive symptoms during 3 follow-up pregnancy points. A multiple linear mixed-effects model was applied to verify the association between dietary patterns and depressive symptoms adjusted for obstetric factors, socioeconomic status, and energy intake. Three prepregnancy dietary patterns were identified: common-Brazilian, healthy, and processed. Together, these patterns explained 36.1% of the total percentage of variance; the eigenvalues were 2.88, 2.12, and 1.86, respectively. Mean depressive symptom scores were 9.0 (95% CI: 8.4, 9.6), 7.2 (95% CI: 6.5, 7.8), and 7.0 (95% CI: 6.4, 7.7) for trimesters 1, 2, and 3, respectively. The rate of decrease in depressive symptoms was -0.088/wk (95% CI: -0.115, -0.061; P < 0.001). In the multiple longitudinal linear regression model, the healthy dietary pattern before pregnancy was inversely associated with depressive symptoms (β:-0.723; 95% CI: -1.277, -0.169; P = 0.011). High adherence to the healthy pattern before pregnancy was associated with lower EPDS scores during pregnancy in women from Rio de Janeiro, Brazil.

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Recebido em 7/8/01; aceito em 2/4/02 SIDEROPHORES: "A MICROORGANISM'S ANSWER". Siderophores (from the Greek: "iron carriers") are defined as relatively low molecular weight, ferric ion specific chelating agents elaborated by microorganisms growing under low iron stress. The role of these compounds is to scavenge iron from the environment and to make this essential chemical element available to the microbial cell. The present paper is a brief presentation of siderophore coordination chemistry with emphasis on those aspects relevant to the transportation of iron (III) complexes across biological membranes. Finally, the role of siderophores in infection and their clinical potential as iron scavenging molecules are reviewed.

rEsumoIntrodução: Os transtornos alimentares (TA) tornaram-se um problema relevante de saúde pública. Paralelamente a esse fato, observa-se aumento na frequência de problemas associados à percepção da imagem corporal. Esses transtornos alimentares são mais incidentes em praticantes de esportes que preconizam o baixo peso corporal, como o balé clássico. Objetivo: Determinar a prevalência de comportamentos de risco de transtornos alimentares e insatisfação com a imagem corporal em bailarinos adolescentes na cidade de São Luís, MA, Brasil. Métodos: Realizou-se estudo transversal com 30 bailarinos clássicos, não profissionais de ambos os sexos, com idade de 15 a 19 anos. Para avaliação do comportamento de risco de anorexia nervosa, utilizou-se o teste de atitudes alimentares (EAT-26), e para o comportamento de risco de bulimia nervosa, o teste de investigação bulímica de Edimburgo (BITE). A imagem corporal foi avaliada por meio do questionário de imagem corporal (BSQ). Resultados: A prevalência de comportamentos de risco de TA foi de 30,0% para anorexia nervosa, de acordo com o EAT-26 e, segundo a escala de sintomas do BITE, 40,0% apresentaram comportamento de risco de bulimia nervosa. Além disso, o BSQ identificou que 26,7% dos bailarinos estavam insatisfeitos com sua imagem. Analisando o comportamento de risco de TA e a insatisfação com a imagem corporal, por sexo, não houve diferença estatisticamente significante (p > 0,05). Conclusão: A alta incidência de insatisfação com a imagem corporal associada à grande prevalência de comportamentos de risco de TA encontrada neste estudo ratifica que a prática do balé parece ser um fator primordial para o aumento da suscetibilidade desses bailarinos desenvolverem TA.Palavras-chave: dança, anorexia nervosa, bulimia nervosa, imagem corporal. AbstrACt Introduction: Eating disorders (ED) have become an important public health problem. Alongside this fact, there is an increase in the frequency

Batista s/nº Valonguinho-24020-150-Niterói-RJ Recebido em 3/10/97; aceito em 2/12/98 MOLECULAR MECHANICS APPLICATION IN INORGANIC CHEMISTRY. The present paper is a review about basic principles of the molecular mechanics that is the most important tool used in molecular modeling area, and their applications to the calculation of the relative stability and chemical reactivity of organometalic and coordination compounds. We show how molecular mechanics can be successfully applied to a wide variety of inorganic systems.

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