306 research outputs found
Effect of One Year of Cryopreservation on the Activity of Lysosomal Hydrolases from EBV-Transformed Lymphocytes
Background. The Epstein-Barr virus (EBV) was used as an agent of B lymphocyte proliferation for subsequent diagnosis of lysosomal storage disease.
Due to the constant handling of long-preserved samples in our cell bank, we decided to observe the behavior and then compare cultured and frozen samples for at least one year's cryopreservation. Methods. Twenty-five samples from healthy individuals were used to assess the
possible changes in activity of enzymes ÎČ-galactosidase, ÎČ-glucosidase, α-iduronidase, α-galactosidase, and α-glucosidase. Transmission electron microscopy was used to confirm cell transformation of B lymphocytes into EBV-infected cells, generating lymphoblastoid cell lines.
Results. Transmission electron microscopy findings confirmed previous reports in the literature that is, significant and evident morphological changes in the nucleus occur after day 12 and the consequent cell transformation into EBV-infected cells. After thawing and subsequent treatment with the five enzymes utilized, we observed no significant changes in samples cryopreserved for more than one year, as compared to samples cultured for 12 days
Contribution from Tree Legumes to Mixed Grass-Legume Pastures
Legumes and associated microorganisms may fix N from atmosphere and benefit grass on mixed grass-legume pastures. Nitrogen may be transferred by different mechanisms, including direct transfer of N compounds by roots, decomposition of nodules, roots, litter from legume (Nair 1993), and through animal excreta after legume intake by cattle. Silvopastoral systems including tree legumes may become a viable option in tropical regions, considering the increasing prices of N fertilizers compared to farm products such as beef and milk.
This experiment evaluated legume contribution on mixed grass-legume pastures in the coastal region of Pernambuco State, Brazil
Lipid-laden multilocular cells in the aging thymus are phenotypically heterogeneous
Intrathymic lipid-laden multilocular cells (LLMC) are known to express pro-inflammatory factors that might regulate functional activity of the thymus. However, the phenotype of ageassociated intrathymic LLMC is still controversial. In this study, we evaluated LLMC density in the aging thymus and better characterized their distribution, ultrastructure and phenotype. Our results show an increased density of LLMC in the thymus from 03 to 24 months of age. Morphologically, intrathymic LLMC exhibit fibroblastoid fusiform, globular or stellate shapes and can be found in the subcapsular region as well as deeper in the parenchyma, including the perivascular area. Some parenchymal LLMC were like telocytes accumulating lipids. We identified lipid droplets with different electrondensities, lipofuscin granules and autolipophagosomelike structures, indicating heterogeneous lipid content in these cells. Autophagosome formation in intrathymic LLMC was confirmed by positive staining for beclin-1 and perilipin (PLIN), marker for lipid droplet-associated proteins.We also found LLMC in close apposition to thymic stromal cells, endothelial cells, mast cells and lymphocytes. Phenotypically, we identified intrathymic LLMC as preadipocytes (PLIN+PPARÎł2+), brown adipocytes (PLIN+UCP1+), macrophages (PLIN+Iba-1+) or pericytes (PLIN+NG2+) but not epithelial cells (PLIN- panCK+). These data indicate that intrathymic LLMC are already present in the young thymus and their density significantly increases with age. We also suggest that LLMC, which are morphologically distinct, establish direct contact with lymphocytes and interact with stromal cells. Finally, we evidence that intrathymic LLMC correspond to not only one but to distinct cell types accumulating lipids
Molecular characterization and sequence analysis of four Brazilian rice stripe necrosis virus isolates.
Rice (Oryza sativa L.) is an important food crop for humanity, being cultivated in tropical and temperate regions of the world. This study reports the nearly complete genome sequences of four Brazilian rice stripe necrosis virus (RSNV) isolates. The nucleotide sequences of the RNA1 and RNA2 genome segments of these Brazilian isolates were 96.5 to 99.9% identical, indicating their close phylogenetic relationship to each other. Phylogeny and recombination analysis indicated that the genome of one of the isolates consisted of RNA segments of different origins, suggesting that a reassortment event had occurred
Innovation, technology and user experience in museums: insights from scientific literature
Museums play an important role in preserving the heritage and cultural legacy of humanity, however, one of their main weaknesses in regards the user is their static nature. At present, and in the face of the development of diverse technologies and the ease of access to information, museums have upgraded their implementation of technologies aimed at improving the user experience, trying more and more to access younger audiences with a sensitivity and natural capacity for the management of new technologies. This work identifies trends in the use of technological tools by museums worldwide and the effect of these on the user or visitor experience through a review of scientific literature. To complete the work, we performed a search of the publications in the ScopusÂź referencing database, and downloaded, processed, and visualized the data using the VOSviewerÂź tool. The main trends identified in this context of analysis are related to the role of museums with the development and improvement of the user experience; orientation to young audiences and innovation driven by the user through Interactive Systems, digital games, QR Codes, apps, augmented reality, virtual reality and gamification, among others. The objective of the implementation of new technologies in the context of museums is to satisfy the needs of contemporary communication, for all types of content and aimed at an increasingly digital audience, in order to ensure positive interaction and feedback from ideas with social and cultural changes
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