Protocatechuic Acid Alkyl Esters: Hydrophobicity As a Determinant Factor for Inhibition of NADPH Oxidase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isotope geochemistry of the mafic dikes from the Vazante nonsulfide zinc deposit, Brazil

The Vazante Group, located in the northwestern part of Minas Gerais, hosts the most important zinc mine in Brazil, the Vazante Mine, which represents a major known example of a hypogene nonsulfide zinc deposit. The main zinc ore is represented by willemite and differs substantially from other deposits of the Vazante-Paracatu region, which are sulfide-dominated zinc-lead ore. The age of the Vazante Group and the hosted mineralization is disputable. Metamorphosed mafic dikes (metabasites) that cut the metasedimentary sequence and are affected by hydrothermal processes recently were found and may shed light on the geochronology of this important geological unit. Zircon crystals recovered from the metabasites are xenocrystic grains that yield U-Pb conventional ages ranging from 2.1 to 2.4 Ga, so the basement of the Vazante Group is Paleoproterozoic or has metasedinientary rocks whose source area was Paleoproterozoic. Pb isotopes determined for titanite separated from the metabasites have common, nonradiogenic Ph compositions, which prevents determination of their crystallization age. However, the Pb signatures observed for the titanite crystals are in agreement with those determined for galena from the carbonate-hosted Zn-Pb deposits hosted by the Vazante Group, including galena from minor sulfide ore bodies of the Vazante deposit. These similarities suggest that the metalliferous fluids that affected the metabasites may have been those responsible for galena formation, which could imply a similar lead source for both nonsulfide and sulfide zinc deposits in the Vazante-Paracatu district. This common source could be related to deep-seated, basin-derived, metalliferous fluids associated with a long-lived hydrothermal system related to diagenesis and deformation of the Vazante Group during the Neoproterozoic. (c) 2005 Elsevier Ltd. All rights reserved.

Ácido cafeico e seus ésteres: inibição do burst oxidativo de neutrófilos e efeito anti-Helicobacter pylori

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização patogênica, morfológica, fisiológica, molecular e sensibilidade a fungicida de Cercospora coffeicola

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alkyl Caffeates as Anti-Helicobacter Pylori and Scavenger of Oxidants Produced by Neutrophils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caffeic Acid Phenethyl Ester: Consequences of Its Hydrophobicity in the Oxidative Functions and Cytokine Release by Leukocytes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geologia da região da Fazenda Salobo, Vazante - MG

Important deposits of Zn-Pb associated with the Vazante Group, and Au in Group Canastra occur in the Vazante-Paracatu region (MG). They are located in the Brasília Fold Belt, which was generated from a convergent tectonic in the Brasiliano cycle, forming a complex system of imbricated nappes and faults. This study aims to characterize stratigraphic, structural and metamorphic aspects of an area, located in the Salobo’s farm region. A geological mapping in 1:20,000 scale was executed in order to identify the outcropping lithotypes and to collect structural measures. Drill holes were described to support the surface data and samples were selected for the preparation of thin and polished sections. In this context, the occurrence of rock types and hydrothermal processes that had not been previously described were found, for example layers of phosphatic quartzite in the Serra do Poço Verde Formation (SPV), hydrothermal hematites from martitization magnetite in contact by detachment of the Serra do Garrote Formation and SPV in the Vazante Group and layers of microbanded iron formations in Paracatu Formation (Canastra Group). In the area, four deformational phases were recognized, occurring progressively, in which two of them are related to convergent tectonic, with the development of thrust faults, one is associated to tectonic escape and/or reactivation of basement faults and the last has a distensive character, representing the post-convergence relaxation. The metamorphism in the area was subgreenschist facies, reaching lower greenschist, with temperatures up to 350°C

Hydrophobicity and antioxidant activity acting together for the beneficial health properties of nordihydroguaiaretic acid

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rastros em chão branco: o sertão de João Guimarães Rosa entre percepções e memórias de travessias

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)