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Efeitos de uma desintegrina RGD recombinante de Rhinocerophis alternatus (Bothrops alternatus) na migração de células normais e tumorais
(Universidade Federal de São Carlos, 2011-08-03) Montenegro, Cyntia de Freitas; Araújo, Heloísa Sobreiro Selistre de; https://lattes.cnpq.br/4065824911933203; https://lattes.cnpq.br/1510751976021672
Cell migration, invasion of the surrounding tissues, blood vessels and proliferation are cellular processes involved in metastases. These events are mediated by integrins, adhesion receptors present on cell surfaces and responsible for the extracellular matrix and cells binding. Disintegrins, snake venoms polypeptides, are known to inhibit integrins action, and thus metastatic events such as cell migration. They also have influence on metallopeptidases activity, enzymes that cleave ECM components facilitating tumor cells invasion. DisBa-01 is a recombinant RGD disintegrin from Rhinocerophis alternatus (Bothrops alternatus) venom gland. In previous studies we have demonstrated that DisBa-01 binds to _v_3 integrin with high affinity and has an anti-metastatic activity. Therefore the aim of this study was to investigate the effect of DisBa-01 on migration and MMPs activities in fibroblasts and cell lines of breast cancer, MDA-MB-231, prostate, DU-145 and murine melanoma, B16F10. Transwell migration tests, wound healing and gelatin gel zymography were performed using DisBa-01 at concentrations of 10, 100, 500 and 1000 nM. Transwell migration was significantly inhibited in fibroblasts, MDA-MB-231 and DU-145 but had no effect on B16F10 cells, which had fibroblast conditioned medium as chemoattractant. In wound healing assays only DU-145 migration in a 1000nM concentration was significantly inhibited. Finally, zymography was performed using wound healing assay conditioned medium to analyze the presence of MMPs 2 and 9. In fibroblasts and B16F10 cells MMP-2 and MMPs 2 and 9 were decreased respectively. On the other hand, MDA-MB-231 cells showed increased MMP-9 activity, in all concentrations tested. Given the results, DisBa-01 can be used to build models for possible drugs rational design that may act in anti-metastatic therapy, in addition to its use as a research tool to elucidate integrins related mechanisms.
Avaliação da resistência ao desgaste de aços inoxidáveis conformados por spray
(Universidade Federal de São Carlos, 2011-08-03) Beraldo, Leamar Guedes; Bolfarini, Claudemiro; https://lattes.cnpq.br/9231627080617037
The aim of this work was the study of the microstructure and the wear resistance of two stainless steels, the ferritic-AIF with 27% Cr and the superduplex-SDM modified with boron (3.5% wt.), processed by spray forming. The rapid solidification promoted by this process has resulted in the formation of a new structure with refined grains and metastable phases. The deposits, weighing about 3.5 kg, were characterized by combination of scanning electron microscopy (SEM), hardness, micro hardness and wear resistance according to ASTM G65-04. The deposits of AIF and SDM showed more refined microstructure and higher hardness in respect to materials produced by conventional casting. The wear resistance of the SDM was higher than the materials tabulated in ASTM G65-04, namely, AISI D2 tool steel and Stellite 1016, while the AIF presented an intermediary value between these two materials. The addition of boron to the SDM is associated with the formation of borides and led to an increase in the hardness and wear resistance of this spray formed material.
Estudo da solidificação do aço rápido M2 em diferentes lingotes e seus efeitos na microestrutura e propriedades mecânicas finais
(Universidade Federal de São Carlos, 2011-08-03) Delgado, Magno Pereira; Ishikawa, Tomaz Toshimi; https://lattes.cnpq.br/5726055117451807; https://lattes.cnpq.br/6017849725670158
The high speed steels are mostly applied in cutting tools, like drills, cores and top milling cutter. Its microstructure is composed by martensite, with high hardness, strong tempering resistance and disperses carbides on its final work condition. The main alloys elements used in the M2 high speed steel are the Mo, W and V. It was studied 3 types of ingots: 150 Kg, 850 Kg and 1700Kg, all of them with a H/D relation (high/ transversal section) = 3. Also, its was studied two of the principal process parameters of the high speed steels, ingot sizes and hot deformation, analyzed by microstructure sizes and mechanical properties. It was analyzed the effects of the ingots sizes, cells sizes and cooling rates in the ingots microstructures and its effects in the microstructure and mechanical properties after the hot deformation by the forging process. The cooling rates, related to the ingot sizes, are variables that affect directly the size and carbides distribution after the forging process, and they will act directly in the final properties of these materials, especially in the wear resistance and toughness. The results show that, even the smaller ingots provide higher cooling rates; its dimensions are not big enough to provide a sufficient reduction area degree in the hot deformation, able to provide adequate mechanical properties. Also, too small ingots are not industrial productiveness. In the other hand, the big ingots, in spite of allow higher deformation rates, and provide more productivity; generate segregation that compromised the final toughness in the ingots. The commitment between the productiveness and the quality are essential and must be considered.
Análise da dinâmica da paisagem em uma região da bacia do rio Corumbataí-SP e suas consequências para o fluxo gênico entre populações
(Universidade Federal de São Carlos, 2011-08-03) Carrocci, Juliana Baggio; Piña-Rodrigues, Fátima Conceição Márquez; https://lattes.cnpq.br/3123312021353708
The Corumbataí River watershed is one of the most degraded areas of the Sao Paulo State due to historical process of use and occupation of their lands. As a result, structural forest fragmentation occurred. These conditions the communities composition and diversity are changed as well as biotic interactions, interfering in gene flow between isolated populations and thus the sustainability of forest remnants. The purpose of this study was to evaluate the changes in land use and cover in the region of Savannah Reserve of Corumbatai, between the years 1978, 1988 and 2000, and its theoretical consequences for gene flow via pollen between populations, using as indicators of habitat quality Euglossina bees. As methodological procedures were used geoprocessing techniques and landscape metrics. The results showed that the process of expansion and intensification of agriculture, especially of sugar cane crop, between the years analyzed was the main cause of deforestation in the region between the period 1978 to 2000, and the savannah was to forest formation the most affected. This process acted in the landscape structural connectivity due to simplify the landscape mosaic, reducing the average size of fragments and increasing isolation among fragments, influencing the functional connectivity of the area to the Euglossina flow. This was mainly due to increasing in the proportion of sugar cane area, crop considered as a barrier to the flow of Euglossina and the reduction of habitats. The results showed that in the study area occurred structural fragmentation process, reflecting in the viii landscape connectivity. This occurred due to inadequate process for use and occupation of land, even after the establishment of conservationists public politics.