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listelement.badge.dso-type Item , Prova de conceito do uso da Plataforma BioSearch para a detecção de resíduos de benzilpenicilina no leite(Universidade Federal de Minas Gerais, 2026-02-24) Lívia de Brito MacedoMilk is a food of high nutritional value and great economic and social importance in Brazil. However, residues of antimicrobials, such as benzylpenicillin, may be present in milk as a result of therapeutic use in lactating cows, especially when there are failures to comply with the withdrawal period, representing risks to public health, losses to the industry, and significant economic losses for the rural producer. To minimize these effects, the detection of antimicrobial residues is regulated by official agencies and commonly performed using sensitive confirmatory tests. Nevertheless, these tests are expensive and not suitable for routine use. As an alternative, screening tests, widely used by producers, enable faster and more cost-effective preliminary detection, although they present limitations in reproducibility and interpretation. Evomilk, a company in the dairy sector, identified the need for more reliable and accessible alternative screening methods for antimicrobial monitoring, which motivated the development of this project. In this context, and in collaboration with Evomilk, this study aimed to demonstrate the proof of concept of the BioSearch Platform for the detection of benzylpenicillin in milk. The platform represents an innovative Brazilian technology based on depolarized dynamic light scattering (D-DLS), employing optical biosensors capable of detecting interactions between analytes and antibodies without the need for secondary markers, thus allowing rapid and in situ measurements. For this purpose, biosensors composed of gold nanorods functionalized with monoclonal IgG anti-penicillin antibodies were developed, capable of recognizing the β-lactam ring of benzylpenicillin. Initial tests performed in reconstituted Difco Skim Milk Powder demonstrated good reproducibility, selectivity and sensitivity for detecting low ppm levels of benzylpenicillin in less than ten minutes. These results indicate that the technology has strong potential to be used as a screening test in farms and cooperatives, enabling the identification of contaminated milk before it reaches dairy plants. Future studies will focus on testing milk samples collected directly from dairies, validation, and improving sensitivity to reach regulatory limits (a few ppb).listelement.badge.dso-type Item , Análise de polimorfismos em antígenos do Trypanosoma cruzi aplicados ao diagnóstico sorológico em humanos(Universidade Federal de Minas Gerais, 2025-08-26) Carlos Henrique Andrade MartinsChagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, persists as a serious global public health problem, and its control is hindered by the absence of a "gold standard" diagnostic test. The vast genetic diversity of the parasite, which is classified into six main Discrete Typing Units (DTUs), is one of the factors that affects the accuracy of serological tests. Many diagnostic antigens have been identified in reference strains that have been grown for logn periods in the laboratory, ignoring the diversity of field isolates. The main objective of this study was to evaluate the conservation and variability of 28 epitopes of T. cruzi, previously described as promising for serodiagnosis, among field isolates of the parasite belonging to the six DTUs, TcI to TcVI, associated with human infections. To this end, an approach based on the analysis of raw sequencing data from 46 read libraries from field isolates, representing these six DTUs, was used. Analyses of conservation, genetic diversity, and population divergence revealed that, among the 28 reference epitopes, 24 variants were recovered in at least one library from each DTU. A more robust subset of 6 epitopes exhibited conservation in 100% of the analyzed read libraries, presenting a high frequency of their encoding reads (≥61.12%) and very low levels of genetic variation among the DTUs. Conversely, epitopes derived from multigene families showed marked polymorphism, characterized by high nucleotide diversity and differentiation among DTUs. Twenty of the 24 identified conserved epitopes were distinct variants from the original reference sequences, indicating that the most immunoreactive epitope described in one strain may not be the most prevalent in natural parasite populations. The study identified seven epitopes as the most promising according to conservation criteria. These results provide an essential basis for the improvement of CD diagnosis by pinpointing conserved antigenic targets in across all examined T. cruzi field isolates.listelement.badge.dso-type Item , Using rodogram function to characterize hurst coefficient in rock profiles([PENDENTE_COMPLETUDE_DSPACE], 2018) David Alvarenga DrumondA rugosidade é uma característica fundamental para definir a deformabilidade e a resistência das rochas. Uma caracterização detalhada da geometria da superfície das descontinuidades é essencial para compreender alguns dos comportamentos mecânicos da rocha. A geometria fractal tem sido utilizada por diversos autores para correlacionar parâmetros como o coeficiente de Hurst com o JRC (coeficiente de rugosidade das juntas), a fim de descrever melhor a geometria da superfície. Perfis de superfície podem ser caracterizados por uma dimensão fractal que representa a recorrência geométrica em pequena escala. Neste artigo, propomos modificar a metodologia utilizada para identificar o coeficiente de Hurst, incorporando a função rodograma na análise do JRC. A função proposta é menos influenciada por efeitos de deriva e parece ser mais precisa do que a função variograma comumente utilizada. Modelos matemáticos robustos de continuidade espacial podem ser uma alternativa melhor para caracterizar a rugosidade das descontinuidades rochosas.listelement.badge.dso-type Item , Rocha contendo biotita como fonte alternativa de potássio para fertilizante após processamento térmico com aditivos([PENDENTE_COMPLETUDE_DSPACE], 2019) Antônio Clareti PereiraBiotite is a ferromagnesian phyllosilicate that contains potassium. It is very abundant and scattered all over the world. Usually formed as a secondary product in metamorphic processes, it is considered to be an impurity in many mineral processing. Even though it is an alternative source of potassium, it is still not extracted commercially on a large scale due to the lack of commercial technology that makes the business viable economically. The objective of this work was to investigate the effect of thermalprocessing, using additives, in the solubilization of potassium and impurities in dilute mineral acid, of rock contains biotite. A rock from the Carajás-Pará-Brazil mineral province, with a content of 9.7% K₂O and 70% biotite was selected. Thermal processing was performed at two temperatures, 800°C and 900°C, for 6h using two systems: (biotite + CaCO₃+ MgCl2.6H2O) and (biotite + gypsum + Na₂CO₃). The sulfuric acid leaching step was performed at pH maintained between 2.0 and 3.0, at 85 °Cfor 1h. The extraction in the system with magnesium chloride (800°C) reached 63% of the potassium and with solubilization maximum of 5% of Fe and Al. The extractions of potassium with gypsum were.listelement.badge.dso-type Item , Converging TLR9 and PI3Kgamma signaling induces sterile inflammation and organ damage(Universidade Federal de Minas Gerais, 2019) Bráulio Henrique Freire Lima; Pedro Elias Marques; Lindisley Ferreira Gomides; Matheus Silvério Mattos; Lucas Kraemer; Celso Martins Queiroz-Junior; Mark Lennon; Emilio Hirsch; Remo Castro Russo; Gustavo Batista Menezes; Edith Hessel; Augustin Amour; Mauro Martins TeixeiraToll-like receptor 9 (TLR9) and Phosphatidylinositol-3-kinase gamma (PI3Kγ) are very important effectors of the immune response, however, the importance of such crosstalk for disease development is still a matter of discussion. Here we show that PI3Kγ is required for immune responses in which TLR9 is a relevant trigger. We demonstrate the requirement of PI3Kγ for TLR9-induced inflammation in a model of CpG-induced pleurisy. Such requirement was further observed in inflammatory models where DNA sensing via TLR9 contributes to disease, such as silicosis and drug-induced liver injury. Using adoptive transfer, we demonstrate that PI3Kγ is important not only in leukocytes but also in parenchymal cells for the progression of inflammation. We demonstrate this crosstalk between TLR9 and PI3Kγ in vitro using human PBMCs. The inhibition of PI3Kγ in CpG-stimulated PBMCs resulted in reduction of both cytokine production and phosphorylated Akt. Therefore, drugs that target PI3Kγ have the potential to treat diseases mediated by excessive TLR9 signalling.