Dissertações em Neurociências e Biologia Celular (Mestrado) - PPGNBC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2375
O Mestrado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
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Item Acesso aberto (Open Access) Dimorfismo sexual da espessura da retina: uma análise de aprendizagem de máquina(Universidade Federal do Pará, 2022-03) FARIAS, Flavia Monteiro; SALOMÃO, Railson Cruz; http://lattes.cnpq.br/9518575270670446; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718; https://orcid.org/0000-0002-4525-3971The present research compared the accuracy of machine learning algorithms in classifying the thickness and volume measurements of retinal layers as obtained from male and female subjects. The study evaluated the retina of sixty-four healthy participants (38 women and 26 men), with normal vision and without eye or systemic diseases, aged between 20 and 40 years. The data acquisition was obtained with a Spectralis HRA+OCT tomograph in the macular region of the retina and its layers: retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigment epithelium (RPE), inner retina (IRL) and outer retina (ORL). The classification accuracy was obtained with the following algorithms: support vector classifier (SVC), logistic regression (LR), linear discriminant analyses (LDA), k-nearest neighbors (kNN), decision tree (DT), gaussian naive bayes (GNB) and random forest (RF). The characteristics attributed to each participant's samples were the thickness values in the nine regions of the macula plus the total macular volume of each retinal layer. The statistical tests Two-way ANOVA and Tukey HSD post-hoc were used in the statistical comparisons between the accuracies for the classifier and retinal layer variables, considering a significance level of < 0.05. All factors (classifier, retinal layer, and their interactions) had significant influences on accuracy (p < 0.05). The main effect of the algorithm type factor resulted in an F ratio of F (6, 630) = 4.527, p = 0.0002. The main effect for the retinal layer produced an F ratio of F (9, 630) = 51.64 and p < 0.0001. The interaction effect was also significant, F(54, 630) = 1.741, p = 0.0012. All algorithms classified with high accuracy (> 0.70) the innermost layers of the retina (total retina, inner retina, RNFL, GCL, INL) according to the gender of the participants, where we observed significant differences between genders in thickness and measurements volume. The SVC, LDA, and LR algorithms produced high accuracy (>0.70) when thickness and volume data came from the RNFL compared to the outermost layers of the retina. The KNN, RF and DT algorithms performed better in correctly classifying the total retina data in relation to the outermost layers. The thickness and volume of the retina and the innermost layers of the retina allow machine learning algorithms to be more accurate in separating data from different sexes.Item Acesso aberto (Open Access) Efeito do óleo da espécie vegetal Caryocar villosum em linhagem de células vero in vitro(Universidade Federal do Pará, 2024-08) LOPES, Izabella Carla Silva; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978; https://orcid.org/0000-0003-3647-9124Fibroblasts are cells that participate in different processes in the body, being indispensable in the development and homeostasis of tissues. They are important agents in the healing process, being present in the inflammatory, proliferative and remodeling phases. These cells produce biomolecules that constitute the extracellular matrix, such as collagen, which provide the necessary support for healthy healing. However, healing is a complex process, and it is proneto failure, so it´s important to investigate therapeutic alternatives to produce more effective treatments in cases where natural healing is not effective. Natural products from plants are widely used as therapeutic forms for healing considering their lower side effects, low cost, this combined with traditional knowledge makes it attractive to studies that prioritize valuing biodiversity. Caryocar villosum (Cv), a fruit native to the Amazon region, is a remarkable source of bioactive compounds with therapeutic potential that has cosmetic and pharmaceutical applications. In this work, the action of Cv oil (CvO) on VERO cell line (fibroblast-like cells)was investigated. The cells were treated with 75, 125 and 250 μg/mL for 24 hours. Cytotoxicity assays, optical microscopy, cell proliferation, morphological analysis, and analysis of extracellular matrix components, such as phalloidin staining and immunofluorescence for type III collagen antibody, were performed. Any cytotoxicity was observed in the cells after CvOtreatment. CvO treatment induced morphological and physiological changes in the cells indicating cell activation. Fluorescence microscopy revealed greater cell spreading, rearrangement of actin filaments and increased cell surface exposure compared to untreated cells. Furthermore, this study suggests that fibroblasts treated with CvO are activated through cytoskeletal rearrangement, increasing cell surface, proliferating, and increasing collagen synthesis. These findings indicate that CvO may be a good therapeutic strategy from biodiversity to stimulate the healing process.Item Acesso aberto (Open Access) Estudos citogenéticos e moleculares nos gêneros Mesomys e Lonchothrix (Rodentia, Echimyidae, Eumysopinae)(Universidade Federal do Pará, 2022-08-29) OLIVEIRA, Leony Dias de; SILVA, Willam Oliveira da; http://lattes.cnpq.br/0903402972891613; https://orcid.org/0000-0003-3125-1075; NAGAMACHI, Cleusa Yoshiko; http://lattes.cnpq.br/8887641213110093; https://orcid.org/0000-0003-1516-2734The Echimyidae family is considered the most taxonomically diverse among South American hystricognathi rodents, comprising 25 genera and 93 species. The subfamily Eumysopinae is represented by nine genera, among which we highlight the arboreal genera Mesomys, which has four recognized species, and Lonchothrix described as monotypic (L. emiliae), both distributed in the Amazon. Morphological, molecular and chromosomal studies in the genera Mesomys and Lonchothrix have contributed to a better understanding of taxonomic design, phylogenetic relationships and karyotypic patterns. Recent molecular investigations have shown an as yet undescribed diversity, suggesting that these taxa are even more diverse than previously assumed. Furthermore, the limits of geographic distribution in the Amazon for the species M. hispidus and M. stimulax have been questioned by some authors. In this sense, the current study sought to investigate the karyotypic diversity and the geographic limits of the Mesomys and Lonchothrix genera, based on classical and molecular cytogenetic analysis and through sequences of the mitochondrial genes Cytochrome b (Cytb) and Cytochrome Oxidase - Subunit I (COI) from different locations in the Brazilian Amazon. The species M. stimulax and Mesomys sp. n. presented 2n=60/NF=110, while M. hispidus presented 2n=60/NF=112 and Lonchothrix emiliae presented 2n=66/NF=126, both unpublished karyotypes for the genera. Phylogenetic analysis confirmed Mesomys and Lonchothrix as sister genera and showed a high intraspecific rate in M. hispidus and Mesomys sp. n. from Itaituba, may be related to a new lineage in the genus Mesomys.