Incorporation of Ag nanoparticles into membrane mimetic systems composed by phospholipid layer-by-layer (LbL) films to achieve surface-enhanced Raman scattering as a tool in drug interaction studies

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

A broad study of two new promising antimycobacterial drugs: Ag(I) and Au(I) complexes with 2-(2-thienyl)benzothiazole

Synthesis, characterization, DFT simulation and biological assays of two new metal complexes of 2-(2-thienyl)benzothiazole - BTT are reported. The complexes [Ag(BTT)(2)NO3] - AgBTT2 and [Au(BTT)Cl]center dot 1/2H(2)O - AuBTT were obtained by mixing the ligand with silver (I) nitrate or gold(I) chloride in methanolic solution. Characterization of the complexes were based on elemental (C, H, N and S), thermal (TG-DTA) analysis, C-13 and H-1 NMR, FT-IR and UV-Vis spectroscopic measurements, as well as the X-ray structure determination for AgBTT2. Spectroscopic data predicted by DFT calculations were in agreement with the experimental data for both complexes. The ligand BTT was synthesized by the condensation of 2-thiophenecarboxaldehyde and 2-aminothiophenol in a microwave furnace. AgBTT2 has a monomeric structure. Both complexes show a good activity against Mycobacterium tuberculosis. Free BIT shows low antitubercular activity. (C) 2012 Elsevier Ltd. All rights reserved.

Synthesis, characterization and antimycobacterial activity of Ag(I)-aspartame, Ag(I)-saccharin and Ag(I)-cyclamate complexes

The present work describes the synthesis and antimycobacterial activity of three Ag(I)-complexes with the sweeteners aspartame, saccharin, and cyclamate as ligands, with the aim of finding new candidate substances for fighting tuberculosis and other mycobacterial infections. The minimal inhibitory concentration of these three complexes was investigated in order to determine their in-vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium malmoense, and Mycobacterium kansasii. The MIC values were determined using the Microplate Alamar Blue Assay. The best MIC values found for the complexes were 9.75 mu M for Ag(l)-aspartame against M. kansasii and 15.7 mu M for Ag(I)-cyclamate against M. tuberculosis.

Efeito nernst anômalo em Materiais com anisotropia magnetocristalina (110)

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Anisotropia magnética (110) em Nanofilmes de Permalloy sobre MgO(100)

The study and fabrication of nanostructured systems composed of magnetic materials has been an area of great scientific and technological interest. Soft magnetic materials, in particular, have had great importance in the development of magnetic devices. Among such materials we highlight the use of alloys of Ni and Fe, known as Permalloy. We present measurement results of structural characterization and magnetic films in Permalloy (Ni81Fe19), known to be a material with high magnetic permeability, low coercivity and small magneto- crystalline anisotropy, deposited on MgO (100) substrates. The Magnetron Sputtering technique was used to obtain the samples with thicknesses varying between 9 150 nm. The techniques of X- ray Diffraction at high and low angle were employed to confirm the crystallographic orientation and thickness of the films. In order to investigate the magnetic properties of the films the techniques of Vibrant Sample Magnetometry (VSM), Ferromagnetic Resonance (FMR) and Magnetoimpedance were used. The magnetization curves revealed the presence of anisotropy for the films of Py/MgO (100), where it was found that there are three distinct axis - an easy-axis for θH = 0°, a hard-axis for θH = 45° and an intermediate for θH = 90°. The results of the FMR and Magnetoimpedance techniques confirm that there are three distinct axes, that is, there is a type C2 symmetry. Then we propose, for these results, the interpretation of the magnetic anisotropy of Py/MgO ( 100 ) is of type simple C2, ie a cubic magnetic anisotropy type ( 110 )

Theoretical analysis of the energy levels induced by oxygen vacancies and the doping process (Co, Cu and Zn) on SnO2 (110) surface models

Density functional calculation at B3LYP level was employed to study the surface oxygen vacancies and the doping process of Co, Cu and Zn on SnO2 (110) surface models. Large clusters, based on (SnO2)(15) models, were selected to simulate the oxidized (Sn15O30), half-reduced (Sn15O29) and the reduced (Sn15O28) surfaces. The doping process was considered on the reduced surfaces: Sn13Co2O28, Sn13Cu2O28 and Sn13Zn2O28. The results are analyzed and discussed based on a calculation of the energy levels along the bulk band gap region, determined by a projection of the monoelectron level structure on to the atomic basis set and by the density of states. This procedure enables one to distinguish the states coming from the bulk, the oxygen vacancies and the doping process, on passing from an oxidized to a reduced surface, missing bridge oxygen atoms generate electronic levels along the band gap region, associated with 5s/5p of four-/five-fold Sn and 2p of in-plane O centers located on the exposed surface, which is in agreement with previous theoretical and experimental investigations. The formation energy of one and two oxygen vacancies is 3.0 and 3.9 eV, respectively. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Periodic study on the structural and electronic properties of bulk, oxidized and reduced SnO2(110) surfaces and the interaction with O-2

The structural and electronic properties of bulk and both oxidized and reduced SnO2(110) surfaces as well as the adsorption process of O-2 on the reduced surface have been investigated by periodic DFT calculations at B3LYP level. The lattice parameters, charge distribution, density of states and band structure are reported for the bulk and surfaces. Surface relaxation effects have been explicitly taken into account by optimizing slab models of nine and seven atomic layers representing the oxidized and reduced surfaces, respectively. The conductivity behavior of the reduced SnO2(110) surface is explained by a distribution of the electrons in the electronic states in the band gap induced by oxygen vacancies. Three types of adsorption approaches of O-2 on the four-fold tin at the reduced SuO(2)(110) surface have been considered. The most exothermic channel corresponds to the adsorption of O-2 parallel to the surface and to the four-fold tin row, and it is believed to be associated with the formation of a peroxo O-2(2-) species. The chemisorption of O-2 on reduced SnO2(110) surface causes a significant depopulation of states along the band gap and it is shown to trap the electrons in the chemisorbed complex producing an electron-depleted space-charge layer in the inner surface region of the material in agreement with some experimental evidences. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Genetic Structure of Populations of the Rice-Infecting Pathogen Rhizoctonia solani AG-1 IA from China

Sheath blight disease (SBD) on rice, caused by Rhizoctonia solani AG-1 IA, is one of the most devastating rice diseases on a global basis, including China (in Eastern Asia), the world's largest rice-growing country. We analyzed the population genetics of nine rice-infecting populations from China using nine microsatellite loci. One allopatric population from India (Southern Asia) was included in the analyses. In total, 300 different multilocus genotypes were found among 572 fungal isolates. Clonal fractions within rice fields were 16 to 95%, suggesting that sclerotia were a major source of primary inoculum in some fields. Global Phi(ST) statistics (Phi(ST) = 42.49; P <= 0.001) were consistent with a relatively high level of differentiation among populations overall; however, pairwise comparisons gave nonsignificant R(ST) values, consistent with contemporary gene flow among five of the populations. Four of these populations were located along the Yangtze River tributary network. Gene flow followed an isolation-by-distance model consistent with restricted long-distance migration. Historical migration rates were reconstructed and yielded values that explained the current levels of population subdivision. Except for one population which appeared to be strictly clonal, all populations showed evidence of a mixed reproductive mode, including both asexual and sexual reproduction. One population had a strictly recombining structure (all loci were in Hardy-Weinberg equilibrium) but the remaining populations from China and the one from India exhibited varying degrees of sexual reproduction. Six populations showed significant F(IS) values consistent with inbreeding.

Divergence Between Sympatric Rice- and Maize-Infecting Populations of Rhizoctonia solani AG-1 IA from Latin America

The basidiomycetous fungus, Rhizoctonia solani anastomosis group (AG)-1 IA is a major pathogen in Latin America causing sheath blight (SB) of rice Particularly in Venezuela. the fungus also Causes banded leaf and sheath blight (BLSB) oil maize, which is considered all emerging disease problem where maize replaced traditional rice-cropping areas or is now planted in adjacent. fields Our goals in this study Were 10 elucidate (i) the effects of host specialization on gene flow between sympatric and allopatric rice and maize-infecting fungal populations and (ii) the reproductive mode of the fungus, looking for evidence of recombination in total, 375 isolates of R. solani AG1 IA sampled from three sympatric rice and maize fields in Venezuela (Porutuguesa State) and two allopatric rice fields from Colombia (Meta State) and Panama (Chiriqui State) were genotyped Using, 10 microsatellite loci Allopatric populations from Venezuela. Colombia. and Panama were significantly differentiated (Phi(ST), of 0 16 to 0 34). Partitioning of the genetic diversity indicated differentiation between sympatric populations from different host species, with 17% of the total genetic variation distributed between hosts while only 3 to 6% wits distributed geographically among the sympatric Venezuelan Fields We detected symmetrical historical migration between the rice- and the maize-infecting populations from Venezuela Rice- and maize-derived isolates were able to infect built rice and maize but were more aggressive Oil their original hosts, consistent with host specialization. Because the maize- and rice-infecting populations are still cross-pathogenic, we postulate that the genetic differentiation was relatively recent and mediated via a host shift. An isolation with nu.-ration analysis indicated that the maize-infecting population diverged from the rice-infecting population between 40 and 240 years ago Our findings also suggest that maize-infecting Populations have a mainly recombining reproductive system whereas the rice-infecting Populations have a Mixed reproductive system in Latin America

The adaptive potential of a plant pathogenic fungus, Rhizoctonia solani AG-3, under heat and fungicide stress

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Severidade da mela da soja causada por Rhizoctonia solani AG-1 IA em função de doses de potássio

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

Influence of Different Professional Prophylactic Methods on Fluorescence Measurements for Detection of Occlusal Caries

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hemangioendothelioma of bone in a patient with a constitutional supernumerary marker

A 13-year old girl was diagnosed as having a bone hemangioendothelioma. Cytogenetic studies identified the presence of a small supernumerary marker chromosome in this patient. Classical cytogenetic methods using G-, C-, Ag-NOR-banding were supplemented by spectral karyotyping (SKY) and fluorescence in situ hybridization to reveal a karyotype 47,XX,+mar.ish der(22)(D22S543+) karyotype in cells derived from the tumor and lymphocytes. These findings suggest that the supernumerary marker chromosome originated from the proximal centromeric region of chromosome 22, and that trisomy of the region 22q11: was not associated with adverse phenotypic effects, but that the presence of trisomy 22q11 may be related to the development of this tumor. (C) Elsevier B.V., 1999. All rights reserved.

Localization of 18S ribosomal genes in suckermouth armoured catfishes Loricariidae (Teleostei, Siluriformes) with discussion on the Ag-NOR evolution

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