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.

Proteoliposomes in nanobiotechnology

Abstract: Proteoliposomes are systems that mimic lipid membranes (liposomes) to which a protein has been incorporated or inserted. During the last decade, these systems have gained prominence as tools for biophysical studies on lipid–protein interactions as well as for their biotechnological applications. Proteoliposomes have a major advantage when compared with natural membrane systems, since they can be obtained with a smaller number of lipidic (and protein) components, facilitating the design and interpretation of certain experiments. However, they have the disadvantage of requiring methodological standardization for incorporation of each specific protein, and the need to verify that the reconstitution procedure has yielded the correct orientation of the protein in the proteoliposome system with recovery of its functional activity. In this review, we chose two proteins under study in our laboratory to exemplify the steps necessary for the standardization of the reconstitution of membrane proteins in liposome systems: (1) alkaline phosphatase, a protein with a glycosylphosphatidylinositol anchor, and (2) Na,K-ATPase, an integral membrane protein. In these examples, we focus on the production of the specific proteoliposomes, as well as on their biochemical and biophysical characterization, with emphasis on studies of lipid–protein interactions. We conclude the chapter by highlighting current prospects of this technology for biotechnological applications, including the construction of nanosensors and of a multi-protein nanovesicular biomimetic to study the processes of initiation of skeletal mineralization.

Biomimetic oxidation of piperine and piplartine catalyzed by iron(III) and manganese(III) porphyrins.

Abstract: Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimetize various reactions of cytochrome P450 enzymes systems in the oxidation of drugs and natural products. The oxidation of piperine and piplartine by iodosylbenzene using iron(III) and manganese(III) porphyrins yielded mono- and dihydroxylated products, respectively. Piplartine showed to be a more reactive substrate towards the catalysts tested. The structures of the oxidation products were proposed based on electrospray ionization tandem mass spectrometry.

Evaluation of local field effect on theI13∕24lifetimes in Er-doped silica-hafnia planar waveguides

Abstract: The spontaneous emission SE rate 0 of the free atom in vacuum is due to the interaction of the free ion with the electromagnetic vacuum fluctuation. 1 When the atom is embedded in a medium, the SE rate suffers a modification because of the changes in the density of electromagnetic states and because of the electromagnetic fields generated by the other atoms in its neighborhood. In an inhomogeneous system containing interfaces, mirrors, and cavities, the two effects cannot be easily separated. However, in a homogeneous system described by the refractive index n, the density of electromagnetic states simply increases by a factor of n 3 with respect to the vacuum level. In the past few years, a lot of theoretical and experimental papers have been focused on the study of the local field effect on emitting ions embedded in dielectric media. 2–8 In an absorption process, the total electromagnetic field, consisting of the sum of the electric field of the incident light Elight and the electric field of the dipole induced by the presence of other atomic species Edip ,i s called the effective field Eef f Eef f= Elight+ Edip. All these effects produce a modification of the decay rate that may be expected to be modified to

The Baurusuchidae vs Theropoda record in the Bauru Group (Upper Cretaceous, Brazil): a taphonomic perspective

Abstract: The Bauru Group is worldwide known due to its high diversity of archosaurs, especially that of Crocodyliformes. Recently, it has been suggested that the Crocodyliformes, especially the Baurusuchidae, were the top predators of the Bauru Group, based on their anatomical convergence with theropods and the dearth of those last ones in the fossil record of this geological group. Here, we erect the hypothesis that assumption is taphonomically biased. For this purpose, we made a literature survey on all the published specimens of Theropoda, Baurusuchidae and Titanosauria from all geological units from the Bauru Group. Also, we gathered data from the available literature, and we classified each fossil find under a taphonomic class proposed on this work. We show that those groups have different degrees of bone representativeness and different qualities of preservation pattern. Also, we suggest that baurusuchids lived close to or in the abundant flood plains, which explains the good preservation of their remains. Theropods and titanosaurs did not live in association with such environments and the quality of their preservation has thus been negatively affected. We support the idea that the Baurusuchidae played an important role in the food chain of the ecological niches of the Late Cretaceous Bauru Group, but the possible biases in their fossil record relative to Theropoda do not support the conclusion that baurusuchids outcompeted theropods. Rather, this taphonomic bias must be tackled first, which previous studies have not regarded.