Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Genus. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

Brazil's government attacks biodiversity.

Abstract: To address the rapid and massive loss of biodiversity worldwide, scientific research must inform agile decision-making. The political leaders of Brazil, the country with the planet's greatest biological wealth ([ 1 ][1]), continue to undermine this goal. In 2001, citing the laudable objective of

Photodynamic therapy with rose bengal induces GroEL expression in Streptococcus mutans.

Abstract: Heat-shock proteins (HSPs) are indicative of stressing conditions that may affect cell viability. In Streptococcus mutans, acid stress induces high levels of GroEL, an HSP, in addition to metabolic alterations, as shown by proteomic analysis. Objective: We tested whether the expression of GroEL by S. mutans was enhanced after photodynamic therapy (PDT) with rose bengal. Methods: S. mutans was grown in complete medium supplemented with 50 mmol/L glucose. The test conditions used were as follows: Rose bengal (0.1 μmol/L) with and without light treatment (500 mJ/cm2), light treatment alone, and 1 mol/L NaCl (as a stress condition). The extracellular pH of bacteria was monitored; HSP expression was assayed with Western blot, and possible DNA damage analyzed. Results: Higher HSP expression was detected in bacteria after PDT treatment as compared with light or dye alone (negative controls). The expression of HSP after PDT was similar to that induced by osmotic stress. No DNA degradation was observed af...

On the origin of red and blue shifts of X-H and C-H stretching vibrations in formic acid (formate ion) and proton donor complexes.

Abstract: Complexes between formic acid or formate anion and various proton donors (HF, H(2)O, NH(3), and CH(4)) are studied by the MP2 and B3LYP methods with the 6-311++G(3df,3pd) basis set. Formation of a complex is characterized by electron-density transfer from electron donor to ligands. This transfer is much larger with the formate anion, for which it exceeds 0.1 e. Electron-density transfer from electron lone pairs of the electron donor is directed into sigma* antibonding orbitals of X--H bonds of the electron acceptor and leads to elongation of the bond and a red shift of the X--H stretching frequency (standard H-bonding). However, pronounced electron-density transfer from electron lone pairs of the electron donor also leads to reorganization of the electron density in the electron donor, which results in changes in geometry and vibrational frequency. These changes are largest for the C--H bonds of formic acid and formate anion, which do not participate in H-bonding. The resulting blue shift of this stretching frequency is substantial and amounts to almost 35 and 170 cm(-1), respectively.

Detection and Selection of Microsatellites in the Genome of Paracoccidioides brasiliensis as Molecular Markers for Clinical and Epidemiological Studies

Abstract: Paracoccidioides brasiliensis, a thermodimorphic fungus, is the causative agent of the prevalent systemic mycosis in Latin America, paracoccidioidomycosis (PCM). Here, we describe the microsatellite patterns observed in a collection of P. brasiliensis random sequence tags. We identified 1,117 microsatellite patterns in about 3.8 Mb of unique sequences (0.47% of the total DNA used in the analysis). The majority of these microsatellites (87.5%) are found in noncoding sequences. We used two polymorphic microsatellites located on noncoding and coding sequences, as well as two microsatellites located on introns, as molecular markers to discriminate P. brasiliensis isolates, to look for relationships between the genetic background of the strains and the types of human disease they cause. We did not observe any correlation between the clinical form of human PCM and four simple sequence repeat patterns analyzed.

The nature of the interactions between Pt4 cluster and the adsorbates *H, *OH, and H2O.

Abstract: The nature of the interactions between the platinum cluster Pt4 and the adsorbates •H, •OH, and H2O, as well as the influence of these adsorbates on the electronic structure of the Pt4 cluster, was investigated by density functional theory (B3LYP, B3PW91, and BP86) together with the effective core potential MWB for the platinum atoms, and 6-311++G(d,p) and aug-cc-pVTZ basis set for the H and O atoms. Identification of the optimal spin multiplicity state and the preferential adsorption sites were also evaluated. Adsorption changes the cluster geometry significantly, but the relaxation effects on the adsorption energy are negligible. The adsorbates bind preferentially atop of the cluster, where high bonding energies were observed for the radical species. Adsorption is followed by a charge transfer from the Pt4 cluster toward radical adsorbates, but this charge transfer occurs in a reversed way when the adsorbate is H2O. In contrast with water, adsorption of the radicals •H and •OH on platinum causes a remar...