2,348 research outputs found
Glycosylation is a key in SARS-CoV-2 infection
SARS-CoV-2 causes the respiratory syndrome COVID-19 and is responsible for the current pandemic. The S protein of SARS-CoV-2-mediating virus binding to target cells and subsequent viral uptake is extensively glycosylated. Here we focus on how glycosylation of both SARS-CoV-2 and target cells crucially impacts SARS-CoV-2 infection at different levels: (1) virus binding and entry to host cells, with glycosaminoglycans of host cells acting as a necessary co-factor for SARS-CoV-2 infection by interacting with the receptor-binding domain of the SARS-CoV-2 spike glycoprotein, (2) innate and adaptive immune response where glycosylation plays both a protective role and contributes to immune evasion by masking of viral polypeptide epitopes and may add to the cytokine cascade via non-fucosylated IgG, and (3) therapy and vaccination where a monoclonal antibody-neutralizing SARS-CoV-2 was shown to interact also with a distinct glycan epitope on the SARS-CoV-2 spike protein. These evidences highlight the importance of ensuring that glycans are considered when tackling this disease, particularly in the development of vaccines, therapeutic strategies and serological testing
Phenylethyl isothiocyanate extracted from watercress by-products with aqueous micellar systems: development and optimisation
Phenylethyl isothiocyanate (PEITC) was reported as a useful antioxidant, anti-inflammatory, and chemopreventive agent. Due to technological and stability issues, it is necessary to be able to extract PEITC from its natural matrix (watercress) through sustainable and scalable methodologies. In this article, we explored, for the first time, the extractive capacity of aqueous micellar systems (AMSs) of two non-ionic surfactants. For this, we compared the AMSs with conventional organic solvents. Furthermore, we developed and optimised a new integral PEITC production and extraction process by a multifactorial experimental design. Finally, we analysed the antioxidant capacity by the oxygen radical absorbance capacity (ORAC) and ABTS methods. As results, the AMSs were able to extract PEITC at the same level as the tested conventional solvents. In addition, we optimised by response surface methodology the integrated process (2.0% m/m, 25.0 C, pH 9.0), which was equally efective (ca. 2900 g PEITC/g watercress), regardless of the surfactant used. The optimal extracts showed greater antioxidant capacity than pure PEITC, due to other antioxidant compounds extracte in the process. In conclusion, by the present work, we developed an innovative cost-effective and low environmental impact process for obtaining PEITC extracts from watercress by-products.N/
Presence and significance of Helicobacter spp. in the gastric mucosa of Portuguese dogs
Background: Non-Helicobacter pylori Helicobacters (NHPH) are also able to cause disease in humans. Dogs are a natural reservoir for many of these species. Close and intense human contact with animals has been identified as a risk factor and therefore, an important zoonotic significance has been attributed to NHPH.
Methods: To determine the prevalence of Helicobacter species and the gastric histopathological changes associated, gastric mucosa samples of 69 dogs were evaluated.
Results: Only one dog presented a normal histopathological mucosa with absence of spiral-shaped organisms. A normal gastric mucosa and the presence of spiral-shaped bacteria was observed in two dogs. All remaining animals presented histopathological changes representative of gastritis. Helicobacter species were detected in 60 dogs (87.0%) by at least one detection method. Histological, histochemical and immunohistochemical evaluations revealed that Helicobacter spp. were present in 45 (65.2%), 52 (75.4%) and 57 (82.6%) dogs, respectively. Spiral-shaped bacteria were detected by qPCR analysis in 33 (47.8%) dogs. H. heilmannii-like organisms were identified in 22 animals (66.7%) and predominantly in the antral gastric region. H. salomonis was the second most prevalent species (51.5%) although it was mainly found in association with other Helicobacter spp. and in the body gastric region. H. bizzozeronii and H. felis were less frequently detected.
Conclusions: It was concluded that, despite the high incidence and worldwide distribution of gastric NHPH in dogs, the presence of specific Helicobacter species may vary between geographic regions. NHPH infections were significantly accompanied by mild to moderate intraepithelial lymphocyte infiltration and mild to moderate gastric epithelial injury, but a clear relationship between gastritis and Helicobacter infection could not be established
Estimativa da vari?vel densidade e seu impacto no planejamento de lavra : estudo de caso mina de Serra Azul.
Programa de P?s-Gradua??o em Engenharia Mineral. Departamento de Engenharia de Minas, Escola de Minas, Universidade Federal de Ouro Preto.Esse trabalho visa mensurar e minimizar os riscos e incertezas associados ?s etapas de
avalia??o de recursos e reservas minerais por meio da incorpora??o da variabilidade da
densidade no planejamento de lavra. Na pr?tica, a maioria dos projetos de minera??o
utilizam um valor de densidade m?dia para cada um dos diferentes tipos litol?gicos
presentes no dep?sito mineral. As determina??es de densidade de min?rio e est?ril
requerem aten??o especial, pois afetam diretamente a convers?o de volumes em
tonelagens e teores em quantidades de metal. Um estudo de caso foi desenvolvido em
uma mina de ferro localizada na regi?o do quadril?tero ferr?fero, onde os efeitos da
incorpora??o das incertezas da vari?vel densidade em um plano de lavra foram
investigados. Para realiza??o dessa an?lise dois cen?rios foram estudados e os seus
resultados comparados. O primeiro consiste em estimar as reservas minerais para o
dep?sito a partir da utiliza??o do atributo densidade determinado pela m?dia das amostras,
enquanto o segundo cen?rio analisa as reservas minerais a partir do atributo densidade
estimado para cada bloco do modelo mediante aplica??o das ferramentas geoestat?sticas.
No desenvolvimento do estudo de caso a metodologia de planejamento de mina
convencional foi utilizada. O impacto de se considerar ou n?o a variabilidade da
densidade na defini??o dos valores aos blocos foi avaliada e, consequentemente, sua
influ?ncia na defini??o dos limites da cava ?tima e no sequenciamento de lavra foi
investigado. Ao comparar os cen?rios estudados observa-se que os resultados dos
trabalhos desenvolvidos utilizando a m?dia do atributo densidade s?o consistentemente
menores do que os resultados dos trabalhos onde o atributo densidade foi estimado. Uma
diferen?a de 3 % na avalia??o dos recursos minerais foi encontrada, enquanto o impacto
na avalia??o das reservas minerais chegou a 5%. A influ?ncia na vida ?til do
empreendimento foi de aproximadamente um ano, impactando o VPL do projeto em 2%.
A reconcilia??o m?ssica para um intervalo de cinco anos de produ??o tamb?m foi
realizada indicando o modelo onde a densidade ? estimada bloco a bloco como o mais
aderente.This study aims to measure and minimize the risks and uncertainties associated with the
mineral resource and mineral reserve estimation steps, incorporating bulk density
variability into the mine planning. In practice, most mining projects use an average bulk
density value for each of the different lithological types present in the mineral deposit.
Ore and waste density determinations require special attention as they directly affect the
conversion of volumes to tonnages and ore grades to metal contents. A case study was
developed in an iron ore mine located in the region of the Iron Quadrangle, MG, Brazil.
In this study, the effects of incorporating bulk density uncertainties in a mining plan were
investigated. In order to perform this analysis two scenarios were studied and their results
were compared. The first one estimate the mineral reserves for the deposit using the bulk
density determined by the samples mean, while the second scenario analyzes the mineral
reserves from the estimated bulk density for each block of the model by applying the
geostatistical tools. In the development of the case study the conventional mine planning
methodology was used. The impact of whether or not to consider the bulk density
variability in the definition of the economic blocks values was evaluated and,
consequently, its influence on the definition of the optimal pit boundaries and the mining
scheduling was investigated. When comparing the studied scenarios, it is observed that
the results of the works developed using the bulk density average are consistently lower
than the results of the works where the bulk density was estimated geostatistically. A 3%
difference in the mineral resources estimation was found, while the impact on the mineral
reserves estimation reached 5%. The influence on the life of mine project was
approximately one year, impacting the project's NPV by 2%. Mining reconciliation for a
five year production interval was also performed indicating the model where bulk density
is estimated block by block as the most adherent
Chitosan-olive oil microparticles for phenylethyl isothiocyanate delivery: optimal formulation
Phenylethyl isothiocyanate (PEITC), a chemopreventive compound, is highly reactive due to its considerably electrophilic nature. Furthermore, it is hydrophobic and has low stability, bioavailability and bioaccessibility. This restricts its use in biomedical and nutraceutical or food applications. Thus, the encapsulation of this agent has the function of overcoming these limitations, promoting its solubility in water, and stabilizing it, preserving its bioactivity. So, polymeric microparticles were developed using chitosan-olive oil-PEITC systems. For this, an optimisation process (factors: olive oil: chitosan ratio and PEITC: chitosan ratio) was implemented through a 3-level factorial experimental design. The responses were: the particle size, zeta-potential, polydisperse index, and entrapment efficiency. The optimal formulation was further characterised by FTIR and biocompatibility in Caco-2 cells. Optimal conditions were olive oil: chitosan and PEITC: chitosan ratios of 1.46 and 0.25, respectively. These microparticles had a size of 629 nm, a zeta-potential of 32.3 mV, a polydispersity index of 0.329, and entrapment efficiency of 98.49%. We found that the inclusion process affected the optical behaviour of the PEITC, as well as the microparticles themselves and their interaction with the medium. Furthermore, the microparticles did not show cytotoxicity within the therapeutic values of PEITC. Thus, PEITC was microencapsulated with characteristics suitable for potential biomedical, nutraceutical and food applications.info:eu-repo/semantics/publishedVersio
As políticas de incentivos aplicadas à fruticultura em proteção integrada na Beira Interior
Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para
cumprimento dos requisitos necessários à obtenção do grau de Mestre em Fruticultura Integrada.Conciliar a produção agrícola e a segurança alimentar com a sustentabilidade ambiental é
um dos maiores desafios que se colocam, atualmente, ao setor agrícola. Neste cenário, a
produção integrada surge, como um método de produção interessante, permitindo a
obtenção de bens alimentares de alta qualidade utilizando os recursos naturais e os
mecanismos de regulação natural em substituição de fatores de produção prejudiciais ao
ambiente assegurando assim, no longo prazo, a sustentabilidade dos ecossistemas.
No respeitante às políticas públicas de apoio ao setor frutícola, o modo de produção
integrada tem vindo a ser estimulado desde a década de 70, beneficiando desde 1995 de
diferentes tipos de apoio resultantes da implementação das medidas agroambientais
constantes dos consecutivos quadros comunitários de apoio.
O presente trabalho permitiu então, avaliar o impacto da implementação das referidas
políticas, com especial incidência no Programa de Desenvolvimento Rural 2007-2013
(PRODER), na evolução do modo de produção integrada no setor frutícola da Beira Interior
(distritos de Castelo Branco e Guarda) através de uma investigação baseada na seguinte
metodologia: (i) análise bibliográfica e documental para enquadramento teórico e
contextualização do objeto de estudo; (ii) análise da informação de base constante no Sistema
de Informação do PRODER (SI PRODER) para identificar e caracterizar os beneficiários e as
operações constantes dos pedidos de apoio apresentados no período 2007-2012.
Na Beira Interior, ao longo dos últimos 25 anos e paralelamente ao sucedido em todo o
país, o setor frutícola foi afetado por uma acentuada redução do total de área destinada à
produção, representando uma diminuição de 21,4% relativamente a 1986. No período
analisado neste estudo verificou-se que, na Beira Interior, a superfície total intervencionada
pelo PRODER foi de 2.512,12 ha, de entre os quais, 1.869,26 ha (74,4%) correspondem a
novas instalações de pomares efetuando-se, na sua grande maioria, na NUT III Cova da Beira.
Ainda do total intervencionado, 62,7% da superfície de pomares apurada, encontra-se
certificada em PRODI correspondendo a 1.574,69 ha.
O investimento total do PRODER no setor da fruticultura na Beira Interior corresponde a
45.001.711,83 euros, do qual, 55,7 % é referente à instalação de jovens agricultores
Expression profile of mucins (MUC2, MUC5AC and MUC6) in Helicobacter pylori infected pre-neoplastic and neoplastic human gastric epithelium
BACKGROUND: Helicobacter pylori (H. pylori) causes gastritis and intestinal metaplasia (IM) that may evolve to gastric carcinoma. The objective of this study was to compare the profile of mucins in the progressive stages of H. pylori infected pre-neoplastic and neoplastic human gastric epithelium. We used a panel of monoclonal antibodies with well-defined specificities of MUC2, MUC5AC and MUC6 to characterize the expression pattern of mucins by immunohistochemistry. METHODS: RUT and ELISA were down for H. pylori confirmation. Human gastric biopsy sections were stained using immunohistochemistry with MUC2, MUC5AC and MUC6 antibodies. RESULTS: MUC5AC was expressed in the superficial epithelium and the upper part of the gastric pits. MUC6 expression was detected in the lower part of the gastric glands. MUC2 was expressed in intestinal metaplasia, mostly in goblet cells. The mucin expression profile in the progressive stages of H. pylori infected human gastric epithelium allows the identification of intestinal metaplasia, which is characterized by a decreased expression of the gastric mucins (MUC5AC and MUC6) and de novo expression of MUC2. CONCLUSION: In conclusion, our results suggest that there is altered expression of MUC5AC and MUC6 together with the aberrant expression of MUC2 in intestinal metaplasia, during the process of gastric carcinogenesis. The present study indicates that the MUC2 mucin expression pattern is a reliable marker of intestinal metaplasia, which appears in the context of H. pylori infected individuals
Phenylethyl isothiocyanate: a bioactive agent for gastrointestinal health
The incidence of gastrointestinal pathologies (cancer in particular) has increased progressively, with considerable morbidity and mortality, and a high economic impact on the healthcare system. The dietary intake of natural phytochemicals with certain bioactive properties has shown therapeutic and preventive effects on these pathologies. This includes the cruciferous vegetable derivative phenylethyl isothiocyanate (PEITC), a bioactive compound present in some vegetables, such as watercress. Notably, PEITC has antioxidant, anti-inflammatory, bactericidal, and anticarcinogenic properties. This review summarized the current knowledge on the role of PEITC as a potential natural nutraceutical or an adjuvant against oxidative/inflammatory-related disorders in the gastrointestinal tract. We also discussed the safe and recommended dose of PEITC. In addition, we established a framework to guide the research and development of sustainable methodologies for obtaining and stabilizing this natural molecule for industrial use. With PEITC, there is great potential to develop a viable strategy for preventing cancer and other associated diseases of the gastrointestinal tract. However, this topic still needs more scientific studies to help develop new PEITC products for the nutraceutical, pharmaceutical, or food industries.info:eu-repo/semantics/publishedVersio
Seleção e composição de uma carteira de ações com base na técnica grafista
This study aims to select the stocks in the Brazilian stock market to compose the portfolio by using the technique analysis. The portfolio selection was in the binging or Augustof 2002. In that moment, twelve stocks were chosen with different proportions. The stocks of corporation were, by decreasing order, the following: Bank of Brazil ON, Embratel PN, Petrobras PN, Itaú Bank PN, Copel PNB, Eletrobrás PNB, Usiminas PNA, Telemar PN, Perdigão PN, Brazil Telepar PN, Bradesco Bank PN, Pão de Açúcar PNA. The results had indicated that, after 12 months, the return of portfolio selection was 94,7%. This performance had been much higher than any other financing market asset, including the indicators of Brazilian stock market as Ibovespa and FVG100. Therefore the technique analysis was powerful process of selecting a portfolio of stock.Key words: portfolio, technique analysis, capital market, stock market; stock exchange.Este estudo objetiva selecionar, por meio da técnica de análise grafista, ações negociadas na Bolsa de Valores brasileira, para compor uma determinada carteira de investimento, além de avaliar o seu desempenho, comparando-o com outros ativos financeiros. A data fixada para composição da carteira foi 2 de agosto de 2002. As 12 ações selecionadas, por ordem de participação na carteira, foram as das seguintes companhias abertas: Banco do Brasil ON, Embratel PN, Petrobrás PN, Banco Itaú PN, Copel PNB, Eletrobrás PNB, Usiminas PNA, Telemar PN, Perdigão PN, Brasil Telepar PN, Banco Bradesco PN e Pão de Açúcar PNA. Os resultados indicaram que, após 12 meses, a rentabilidade da carteira foi de 94,7%. Portanto, esse desempenho foi muito superior ao de quaisquer outras aplicações no mercado financeiro, inclusive dos próprios fundos de investimentos ou indicadores baseados em preços de ações como Ibovespa e FGV100. A análise grafista tem se apresentado potente no processo de seleção e composição da carteira de ações.Palavras-chave: carteira de ativos, análise técnica, mercado de capitais, carteira de ações, bolsa de valores
Seleção e composição de uma carteira de ações com base na técnica grafista
This study aims to select the stocks in the Brazilian stock market to compose the portfolio by using the technique analysis. The portfolio selection was in the binging or Augustof 2002. In that moment, twelve stocks were chosen with different proportions. The stocks of corporation were, by decreasing order, the following: Bank of Brazil ON, Embratel PN, Petrobras PN, Itaú Bank PN, Copel PNB, Eletrobrás PNB, Usiminas PNA, Telemar PN, Perdigão PN, Brazil Telepar PN, Bradesco Bank PN, Pão de Açúcar PNA. The results had indicated that, after 12 months, the return of portfolio selection was 94,7%. This performance had been much higher than any other financing market asset, including the indicators of Brazilian stock market as Ibovespa and FVG100. Therefore the technique analysis was powerful process of selecting a portfolio of stock.Key words: portfolio, technique analysis, capital market, stock market; stock exchange.Este estudo objetiva selecionar, por meio da técnica de análise grafista, ações negociadas na Bolsa de Valores brasileira, para compor uma determinada carteira de investimento, além de avaliar o seu desempenho, comparando-o com outros ativos financeiros. A data fixada para composição da carteira foi 2 de agosto de 2002. As 12 ações selecionadas, por ordem de participação na carteira, foram as das seguintes companhias abertas: Banco do Brasil ON, Embratel PN, Petrobrás PN, Banco Itaú PN, Copel PNB, Eletrobrás PNB, Usiminas PNA, Telemar PN, Perdigão PN, Brasil Telepar PN, Banco Bradesco PN e Pão de Açúcar PNA. Os resultados indicaram que, após 12 meses, a rentabilidade da carteira foi de 94,7%. Portanto, esse desempenho foi muito superior ao de quaisquer outras aplicações no mercado financeiro, inclusive dos próprios fundos de investimentos ou indicadores baseados em preços de ações como Ibovespa e FGV100. A análise grafista tem se apresentado potente no processo de seleção e composição da carteira de ações.Palavras-chave: carteira de ativos, análise técnica, mercado de capitais, carteira de ações, bolsa de valores
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