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1.
Sensors (Basel) ; 23(21)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37960591

RESUMO

There is only a very short reaction time for people to find the best way out of a building in a fire outbreak. Software applications can be used to assist the rapid evacuation of people from the building; however, this is an arduous task, which requires an understanding of advanced technologies. Since well-known pathway algorithms (such as, Dijkstra, Bellman-Ford, and A*) can lead to serious performance problems, when it comes to multi-objective problems, we decided to make use of deep reinforcement learning techniques. A wide range of strategies including a random initialization of replay buffer and transfer learning were assessed in three projects involving schools of different sizes. The results showed the proposal was viable and that in most cases the performance of transfer learning was superior, enabling the learning agent to be trained in times shorter than 1 min, with 100% accuracy in the routes. In addition, the study raised challenges that had to be faced in the future.


Assuntos
Aprendizagem , Reforço Psicológico , Humanos , Algoritmos , Software , Instituições Acadêmicas
2.
Cell Tissue Bank ; 17(4): 689-697, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27718130

RESUMO

The aim of this paper was to evaluate through histological analysis of the tissue reaction of deproteinized bovine bone matrix (DBBM) when inserted into the site of intramuscular ectopic sheep. In this study, 16 sheep received 3 groups and these were divided into 2 experimental times: Group 1-sham group, Group 2-particulate autogenous bone and Group 3-DBBM granules. All animals underwent surgical procedures for insertion of materials in an ectopic site (muscles of the lower back and after 3 and 6 months postoperatively, the samples were evaluated by histological analysis. The results indicated that the Sham group showed dense collagen fibers and thin, characterizing fibrosis at 3 and 6 months. In the autograft group there was a significant amount of collagen deposition and decreased inflammation at 6 months postoperatively. Group of DBBM, it was noted the presence of dense connective tissue and surrounding remaining particles was observed the formation of with osteoid characteristic tissue. The DBBM demonstrated biocompatibility, osteoconductivity and small osteogenesis capacity on ectopic site.


Assuntos
Matriz Óssea/química , Matriz Óssea/transplante , Transplante Ósseo , Músculos/cirurgia , Osteogênese , Animais , Regeneração Óssea , Substitutos Ósseos/química , Substitutos Ósseos/uso terapêutico , Transplante Ósseo/métodos , Bovinos , Colágeno/análise , Músculos/ultraestrutura , Proteínas/isolamento & purificação , Ovinos
3.
Antiviral Res ; 229: 105968, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39004311

RESUMO

Since human angiotensin-converting enzyme 2 (ACE2) serves as a primary receptor for SARS-CoV-2, characterizing ACE2 regions that allow SARS-CoV-2 to enter human cells is essential for designing peptide-based antiviral blockers and elucidating the pathogenesis of the virus. We identified and synthesized a 25-mer mimetic peptide (encompassing positions 22-46 of the ACE2 alpha-helix α1) implicated in the S1 receptor-binding domain (RBD)-ACE2 interface. The mimetic (wild-type, WT) ACE2 peptide significantly inhibited SARS-CoV-2 infection of human pulmonary Calu-3 cells in vitro. In silico protein modeling predicted that residues F28, K31, F32, F40, and Y41 of the ACE2 alpha-helix α1 are critical for the original, Delta, and Omicron strains of SARS-CoV-2 to establish the Spike RBD-ACE2 interface. Substituting these residues with alanine (A) or aspartic acid (D) abrogated the antiviral protective effect of the peptides, indicating that these positions are critical for viral entry into pulmonary cells. WT ACE2 peptide, but not the A or D mutated peptides, exhibited significant interaction with the SARS-CoV-2 S1 RBD, as shown through molecular dynamics simulations. Through identifying the critical amino acid residues of the ACE2 alpha-helix α1, which is necessary for the Spike RBD-ACE2 interface and mobilized during the in vitro viral infection of cells, we demonstrated that the WT ACE2 peptide protects susceptible K18-hACE2 mice against in vivo SARS-CoV-2 infection and is effective for the treatment of COVID-19.

4.
Front Immunol ; 13: 948419, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36148232

RESUMO

The autoimmune regulator (AIRE) protein functions as a tetramer, interacting with partner proteins to form the "AIRE complex," which relieves RNA Pol II stalling in the chromatin of medullary thymic epithelial cells (mTECs). AIRE is the primary mTEC transcriptional controller, promoting the expression of a large set of peripheral tissue antigen genes implicated in the negative selection of self-reactive thymocytes. Under normal conditions, the SIRT1 protein temporarily interacts with AIRE and deacetylates K residues of the AIRE SAND domain. Once the AIRE SAND domain is deacetylated, the binding with SIRT1 is undone, allowing the AIRE complex to proceed downstream with the RNA Pol II to the elongation phase of transcription. Considering that the in silico and in vitro binding of the AIRE SAND domain with SIRT1 provides a powerful model system for studying the dominant SAND G228W mutation mechanism, which causes the autoimmune polyglandular syndrome-1, we integrated computational molecular modeling, docking, dynamics between the whole SAND domain with SIRT1, and surface plasmon resonance using a peptide harboring the 211 to 230 residues of the SAND domain, to compare the structure and energetics of binding/release between AIRE G228 (wild-type) and W228 (mutant) SAND domain to SIRT1. We observed that the G228W mutation in the SAND domain negatively influences the AIRE-SIRT1 interaction. The disturbed interaction might cause a disruption in the binding of the AIRE SAND domain with the SIRT1 catalytic site, impairing the AIRE complex to proceed downstream with RNA Pol II.


Assuntos
RNA Polimerase II , Sirtuína 1 , Cromatina , Regulação da Expressão Gênica , Mutação , Peptídeos , Sirtuína 1/genética
5.
Quintessence Int ; 46(2): 139-44, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25279396

RESUMO

The use of dental implants to improve functional and esthetic demands of dentition has increased significantly over the past two decades. Soft and hard tissue management is one of the factors contributing to improved esthetic results. This report describes the correction of an esthetic problem in a single implant combined connective tissue graft and autogenous bone graft. Four months after the surgical procedure, it could be observed that the combination of connective tissue graft and autogenous bone graft resulted in the augmentation of hard and soft tissue in the peri-implant area with favorable esthetic outcomes.


Assuntos
Aumento do Rebordo Alveolar/métodos , Transplante Ósseo/métodos , Tecido Conjuntivo/transplante , Implantação Dentária Endóssea , Implantes Dentários para Um Único Dente , Estética Dentária , Gengiva/cirurgia , Dente Pré-Molar , Feminino , Humanos , Pessoa de Meia-Idade , Retalhos Cirúrgicos
6.
Artigo em Português | ARCA | ID: arc-17516

RESUMO

As tecnologias de Internet mudaram o desenvolvimento de software. As mudanças afetam uma gama completa de aplicações, assim como a forma em que os usuários interagem com os computadores. No campo da saúde, a pesquisa médica demanda muito investimento, esforço e informações para a comercialização segura de um fármaco novo. O projeto WebInVivo visa fornecer suporte automatizado à pesquisa médica, alicerçado em tecnologias de Internet. Ele inclui mecanismos para o compartilhamento e a reutilização de informações de pesquisas médicas, tais como protocolos, dados de protocolos, fluxos de trabalho e metadados de fluxos de trabalho para o controle do ciclo de vida do protocolo, da modelagem à execução. Neste projeto, o conhecimento da área biomédica permeia três segmentos da sociedade brasileira: (a) pesquisa e desenvolvimento, (b) agentes de saúde e (c) a população. Este conhecimento será disponibilizado em redes sociais, para esses segmentos da sociedade brasileira.

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