92 research outputs found

    Microglial cell-mediated anti-Candida activity: temperature, ions, protein kinase C as crucial elements.

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    An in vitro established microglial cell line, BV-2, constitutively exhibits high levels of anti-Candida activity. To elucidate the cascade of events leading to the accomplishment of such activity, we studied its dependence on temperature and ion availability. The role of protein kinases has also been studied by the specific inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7) and N-(2-guanidinoethyl)-5-isoquinoline sulfonamide hydrochloride (HA 1004). We found that (a) the BV-2 cell/Candida conjugate formation is a discrete step, temperature-, ion- and protein kinase-independent; (b) the phagocytic event, which is protein kinase-independent, is significantly impaired by temperature decrease and ion deprivation; (c) the fulfillment of anti-Candida effects is strictly dependent upon temperature, ion availability and functional protein kinase. Functional protein kinase C, but not other kinases, is required for the accomplishment of anti-Candida activity, which, in fact, is selectively abrogated by H7 but not HA. Furthermore, protein kinase C activators, such as 12-O-tetradecanoylphorbol 13-acetate (TPA) or 1-oleoyl-2-acetyl glycerol (OAG), consistently potentiate BV-2 cell-mediated anti-Candida activity, the phenomena being dose-dependent. These results indicate that the multistep events leading a microglial cell to express anti-Candida activity can be dissected and differentiated for biochemical and biological demands, the latest along the cascade being the most demanding steps

    Metodologia para implantaçăo de serviços digitais em uma Rede HFC existente /

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    Orientador: Horácio Tertuliano FilhoInclui apęndiceDissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduaçăo em Engenharia Elétrica. Defesa: Curitiba, 2006Inclui bibliografiaResumo: As redes de televisăo via cabo estăo emergindo como uma importante infraestruturapara disponibilizar conteúdos interativos e acessos em alta velocidade embanda larga ŕ rede mundial de computadores. Neste contexto, as redes HFC (HybridFiber-Coax) săo cada vez mais exigidas nos aspectos de qualidade no transporte desinais digitais e deixam de ser apenas redes de transportes de canais de televisăoanalógica, devido a disponibilidade de banda de transmissăo e a capilaridade na suaárea de cobertura.Este trabalho abordará o desenvolvimento de uma metodologia de trabalhostécnicos que deverăo ter como resultados finais a vantagem de melhorar o desempenhoda infra-estrutura existente, e em assim sendo, poder disponibilizar o maior conteúdode programaçăo e o maior número de serviços, conseqüentemente maior interatividadeaos seus clientes, com o melhor aproveitamento possível do espectro de freqüęncia.Será apresentado, primeiramente, um estudo sistęmico destacando os conceitos básicosda rede HFC, a padronizaçăo do sistema de cable modem e do sistema de televisăodigital. Em seguida, serăo apresentados os cálculos necessários, destacando osparâmetros de qualidade da rede HFC para o plano de canalizaçăo analógica e planode canalizaçăo para o transporte de vídeo e dados digitais. Posteriormente, seráapresentada uma metodologia de procedimentos técnicos operacionais que deverá serseguida para extrair o melhor desempenho da rede existente e poder, dessa forma,assegurar a qualidade dos serviços prestados pela operadora. Finalmente, umadiscussăo sobre os resultados aplicados em campo como forma de validaçăo dasmetodologias desenvolvidas, com o estudo de caso de uma área de interesse o qualservirá como base para implementaçőes futuras

    The Role of Nitric Oxide in Mycobacterial Infections

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    Although tuberculosis poses a significant health threat to the global population, it is a challenge to develop new and effective therapeutic strategies. Nitric oxide (NO) and inducible NO synthase (iNOS) are important in innate immune responses to various intracellular bacterial infections, including mycobacterial infections. It is generally recognized that reactive nitrogen intermediates play an effective role in host defense mechanisms against tuberculosis. In a murine model of tuberculosis, NO plays a crucial role in antimycobacterial activity; however, it is controversial whether NO is critically involved in host defense against Mycobacterium tuberculosis in humans. Here, we review the roles of NO in host defense against murine and human tuberculosis. We also discuss the specific roles of NO in the central nervous system and lung epithelial cells during mycobacterial infection. A greater understanding of these defense mechanisms in human tuberculosis will aid in the development of new strategies for the treatment of disease

    The Ny-Ålesund Aerosol Cloud Experiment (NASCENT): Overview and First Results

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    The Arctic is warming at more than twice the rate of the global average. This warming is influenced by clouds, which modulate the solar and terrestrial radiative fluxes and, thus, determine the surface energy budget. However, the interactions among clouds, aerosols, and radiative fluxes in the Arctic are still poorly understood. To address these uncertainties, the Ny-Ålesund Aerosol Cloud Experiment (NASCENT) study was conducted from September 2019 to August 2020 in Ny-Ålesund, Svalbard. The campaign’s primary goal was to elucidate the life cycle of aerosols in the Arctic and to determine how they modulate cloud properties throughout the year. In situ and remote sensing observations were taken on the ground at sea level, at a mountaintop station, and with a tethered balloon system. An overview of the meteorological and the main aerosol seasonality encountered during the NASCENT year is introduced, followed by a presentation of first scientific highlights. In particular, we present new findings on aerosol physicochemical and molecular properties. Further, the role of cloud droplet activation and ice crystal nucleation in the formation and persistence of mixed-phase clouds, and the occurrence of secondary ice processes, are discussed and compared to the representation of cloud processes within the regional Weather Research and Forecasting Model. The paper concludes with research questions that are to be addressed in upcoming NASCENT publications

    Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia.

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    ABSTARCT: Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease. METHODS: Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique. RESULTS: In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X. CONCLUSIONS: This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis

    Metodologia para implantaçăo de serviços digitais em uma Rede HFC existente /

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    Orientador: Horácio Tertuliano FilhoInclui apęndiceDissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduaçăo em Engenharia Elétrica. Defesa: Curitiba, 2006Inclui bibliografiaResumo: As redes de televisăo via cabo estăo emergindo como uma importante infraestruturapara disponibilizar conteúdos interativos e acessos em alta velocidade embanda larga ŕ rede mundial de computadores. Neste contexto, as redes HFC (HybridFiber-Coax) săo cada vez mais exigidas nos aspectos de qualidade no transporte desinais digitais e deixam de ser apenas redes de transportes de canais de televisăoanalógica, devido a disponibilidade de banda de transmissăo e a capilaridade na suaárea de cobertura.Este trabalho abordará o desenvolvimento de uma metodologia de trabalhostécnicos que deverăo ter como resultados finais a vantagem de melhorar o desempenhoda infra-estrutura existente, e em assim sendo, poder disponibilizar o maior conteúdode programaçăo e o maior número de serviços, conseqüentemente maior interatividadeaos seus clientes, com o melhor aproveitamento possível do espectro de freqüęncia.Será apresentado, primeiramente, um estudo sistęmico destacando os conceitos básicosda rede HFC, a padronizaçăo do sistema de cable modem e do sistema de televisăodigital. Em seguida, serăo apresentados os cálculos necessários, destacando osparâmetros de qualidade da rede HFC para o plano de canalizaçăo analógica e planode canalizaçăo para o transporte de vídeo e dados digitais. Posteriormente, seráapresentada uma metodologia de procedimentos técnicos operacionais que deverá serseguida para extrair o melhor desempenho da rede existente e poder, dessa forma,assegurar a qualidade dos serviços prestados pela operadora. Finalmente, umadiscussăo sobre os resultados aplicados em campo como forma de validaçăo dasmetodologias desenvolvidas, com o estudo de caso de uma área de interesse o qualservirá como base para implementaçőes futuras

    Desain Glass Bottom Catamaran Boat dengan Panel Surya di Kepulauan Mentawai, Sumatera Barat

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    Mentawai merupakan salah satu kabupaten yang terletak di Provinsi Sumetera Barat. Secara geografis, Kabupaten Kepulauan Mentawai berada terpisah dari Provinsi Sumatera Barat. Mentawai terdiri dari 4 pulau besar dan juga sebagai salah satu tempat wisata yang terkenal akan ombaknya. Selain berselancar, kawasan ini juga memiliki spot snorkeling dan diving. Salah satunya di kawasan Taman Kima yang berada di Pulau Sipora. Di sana para wisatawan dapat melihat kima atau yang biasa disebut kerang raksasa. Namun, kapal wisata yang beroperasi di Kepulauan Mentawai masih sangat sedikit dan belum terdapat glass bottom boat yang beroperasi di Kepulauan Mentawai. Tujuan dari Tugas Akhir ini adalah melakukan desain kapal yang dapat mengakomodasi penumpang untuk melihat pemandangan bawah laut di perairan Kepulauan Mentawai tanpa harus menyelam, melalui material transparan yaitu akrilik yang dipasang pada kedua lambung kapal. Alasannya digunakannya katamaran karena katamaran memiliki geladak yang lebih luas dan stabilitas yang lebih baik dibandingkan monohull. Penggunaan panel surya bertujuan untuk mengurangi konsumsi bahan bakar dan ramah lingkungan. Sumber energi electric motor ini adalah generator dan baterai, yang bersumber dari panel surya. Penentuan ukuran utama kapal menggunakan parent ship design. Penentuan payload menggunakan metode forecasting dari data jumlah kunjungan wisatawan di Kepulauan Mentawai dan hasil kuisioner ketertarikan wisata di Kepulauan Mentawai. Kemudian didapatkan payload sebanyak 50 orang. Ukuran utama yang memenuhi kriteria teknis dan regulasi adalah Lpp = 24.50 m; B =9.80 m; H = 4.50 m; T = 2.50 m. Tinggi freeboard minimum sebesar 0.853 m. Untuk estimasi biaya pembangunan kapal sebesar Rp. 17,586,012,016 dengan IRR 17% pada penumpang 50%. ====================================================================================================== Mentawai is one of the regencies located in West Sumetera Province. Geographically, Mentawai Islands Regency is separated from West Sumatera Province. Mentawai consists of 4 large islands and is also one of the tourist attractions famous for its waves. In addition to surfing, the area also has snorkeling and diving spots. One of them is in the Kima Park area on Sipora Island. There, tourists can see giant clams or the so-called kima. However, tourist ships operating in the Mentawai Islands are still very few and there are no glass bottom boats operating in the Mentawai Islands. The purpose of this Final Assignment is to design a ship that can accommodate passengers to see the underwater scenery in the waters of the Mentawai Islands without having to dive, through transparent material that is acrylic mounted on both hulls. The reason for the use of katamarans is because the katamaran has a wider deck and better stability than monohull. The use of solar panels aims to reduce fuel consumption and be environmentally friendly. Electric motor's energy sources are generators and batteries, sourced from solar panels. Determination of the main size of the ship using parent ship design. Determination of payload using forecasting method from data on the number of tourist visits in Mentawai Islands and the results of questionnaires of tourist interest in the Mentawai Islands. Then get a payload of 50 people. The main size that meets the technical and regulatory criteria is Lpp = 24.50 m; B =9.80 m; H = 4.50 m; T = 2.50 m. Minimum freeboard height is 0.853 m. Building cost Rp. 17,586,012,016, IRR 17% for 50% passanger
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