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Search Results: 1 - 10 of 1641 matches for " Edna;SABINO "
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Significance of isolated hepatitis B core antibody in blood donors from S o Paulo
ALMEIDA NETO Cesar de,STRAUSS Edna,SABINO Esther Cerdeira,SUCUPIRA Maria Cecília Araripe
Revista do Instituto de Medicina Tropical de S?o Paulo , 2001,
Abstract: The clinical significance of isolated anti-HBc is still a challenge. To elucidate the real importance of this finding in our blood donors, an investigation algorithm was tested. One hundred and twelve isolated anti-HBc seropositive blood donors underwent clinical evaluation and retesting of HBV markers. Those who presented repeatedly reactive isolated anti-HBc, received a single dose of hepatitis B recombinant vaccine to verify anti-HBs early response. A HBV-DNA determination by PCR was done for those who did not test positive to anti-HBs after vaccine. The level of anti-HBc was recorded as a ratio of the sample-to-cut-off values (S:C ratio) in 57 candidates at donation. Comparing true and false-positive anti-HBc results, the different S:C ratios of them were statistically significant and when less than 2, implying in a false-positive result probability over 80%. A high percent of false-positive results (16.07%) was verified after anti-HBc retesting. HBV immunity was characterized in 49.11%, either by anti-HBs detection in retesting (15.18%), or after a single dose HBV vaccination (33.93%). HBV-DNA was negative in all tested donors. In conclusion, this algorithm was useful to clarify the meaning of isolated anti-HBc in most of our blood donors.
Liver histology in co-infection of hepatitis C virus (HCV) and Hepatitis G virus (HGV)
STRAUSS, Edna;GAYOTTO, Luiz Carlos da Costa;FAY, Fabian;FAY, Oscar;FERNANDES, Helena Sabino;CHAMONE, Dalton de Alencar Fischer;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2002, DOI: 10.1590/S0036-46652002000200003
Abstract: as little is known about liver histology in the co-infection of hepatitis c virus (hcv) and hepatitis g virus (hgv), hgv rna was investigated in 46 blood donors with hepatitis c, 22 of them with liver biopsy: co-infection hcv / hgv (n = 6) and hcv isolated infection (n = 16). besides staging and grading of inflammation at portal, peri-portal and lobular areas (brazilian consensus), the fibrosis progression index was also calculated. all patients had no symptoms or signs of liver disease and prevalence of hgv / hcv co-infection was 15.2%. most patients had mild liver disease and fibrosis progression index, calculated only in patients with known duration of infection, was 0.110 for co-infection and 0.130 for isolated hcv infection, characterizing these patients as "slow fibrosers". no statistical differences could be found between the groups, although a lesser degree of inflammation was always present in co-infection. in conclusion co-infection hcv / hgv does not induce a more aggressive liver disease, supporting the hypothesis that hgv is not pathogenic.
Significance of isolated hepatitis B core antibody in blood donors from S?o Paulo
ALMEIDA NETO, Cesar de;STRAUSS, Edna;SABINO, Esther Cerdeira;SUCUPIRA, Maria Cecília Araripe;CHAMONE, Dalton de Alencar Fischer;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2001, DOI: 10.1590/S0036-46652001000400005
Abstract: the clinical significance of isolated anti-hbc is still a challenge. to elucidate the real importance of this finding in our blood donors, an investigation algorithm was tested. one hundred and twelve isolated anti-hbc seropositive blood donors underwent clinical evaluation and retesting of hbv markers. those who presented repeatedly reactive isolated anti-hbc, received a single dose of hepatitis b recombinant vaccine to verify anti-hbs early response. a hbv-dna determination by pcr was done for those who did not test positive to anti-hbs after vaccine. the level of anti-hbc was recorded as a ratio of the sample-to-cut-off values (s:c ratio) in 57 candidates at donation. comparing true and false-positive anti-hbc results, the different s:c ratios of them were statistically significant and when less than 2, implying in a false-positive result probability over 80%. a high percent of false-positive results (16.07%) was verified after anti-hbc retesting. hbv immunity was characterized in 49.11%, either by anti-hbs detection in retesting (15.18%), or after a single dose hbv vaccination (33.93%). hbv-dna was negative in all tested donors. in conclusion, this algorithm was useful to clarify the meaning of isolated anti-hbc in most of our blood donors.
Serological, epidemiological and molecular aspects of hepatitis C virus infection in a population from Londrina, PR, Brazil, 2001-2002
Vogler, Ingridt Hildegard;Nishiya, Anna;Morimoto, Helena Kaminami;Reiche, Edna Maria Vissoci;Bortoliero, André Luiz;Matsuo, Tiemi;Sabino, Ester Cerdeira;Vaz, Adelaide Jose;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2004, DOI: 10.1590/S0036-46652004000600002
Abstract: serological, epidemiological and molecular aspects of hepatitis c virus (hcv) infection were evaluated in 183 subjects from londrina, paraná, brazil, and adjacent areas. serum samples which tested anti-hcv positive by microparticle enzyme immunoassay (meia) obtained from eight patients with chronic hepatitis c, 48 blood donors, and 127 patients infected with the human immunodeficiency virus (hiv) were submitted to another enzyme immunoassay (elisa) and to the polymerase chain reaction (pcr). about 78.7% of samples were also reactive by elisa, with the greater proportion (70.8%) of discordant results verified among blood donors. a similar finding was observed for hcv-rna detection by pcr, with 111/165 (67.3%) positive samples, with higher rates among hiv-positive subjects and patients with chronic hepatitis than among blood donors. sixty-one pcr-positive samples were submitted to hcv genotyping, with 77.1, 21.3 and 1.6% of the samples identified as types 1, 3 and 2, respectively. finally, analysis of some risk factors associated with hcv infection showed that intravenous drug use was the most common risk factor among hiv/hcv co-infected patients, while blood transfusion was the most important risk factor in the group without hiv infection. the present study contributed to the knowledge regarding risk factors associated with hcv infection and the distribution of hcv genotypes in the population evaluated.
Fabrication and characterization of gold ultra and microelectrodes
Menolasina,Sabino;
Revista Técnica de la Facultad de Ingeniería Universidad del Zulia , 2004,
Abstract: gold disk ultramicroelectrodes of 10 μm and microelectrodes of 60 μm diameter were fabricated using gold wires. these ultra and microelectrodes were characterized by electrochemical measurements and using scanning electron microscopy (sem) for determining the real shape of the surface, and obtaining information about the quality of the seal at the electrode material-insulating material interface.
Electrochemical study of the underpotential deposition of PB on gold ultramicroelectrodes
Menolasina,Sabino;
Revista Técnica de la Facultad de Ingeniería Universidad del Zulia , 2004,
Abstract: gold disc electrodes of 10 mm diameter were fabricated using gold wires. the underpotential deposition (upd) of lead on gold ultramicrodisks was investigated by cyclic voltammetry and chronoamperometry, using dilute solutions of pb2+ in 0.2 mol dm-3 hclo4. the upd of pb(0) occurs between 0 v and -0.4 v vs. sce. the process of underpotential deposition is controlled by diffusion. the results of voltammetry experiments show that a monolayer of lead is formed in the upd region. the results of the chronoamperometry experiments demostrate that the formation of a complete monolayer can be related to the appearence of a nonmonotonic current-time transient.
Electrochemical studies of Fe(CN)6(4-)/Fe(CN)6(3-) on gold ultramicroelectrodes varying the concentrations of KF as supporting electrolyte
Menolasina,Sabino;
Revista Técnica de la Facultad de Ingeniería Universidad del Zulia , 2005,
Abstract: gold disk ultramicroelectrodes of 10 mm diameter were fabricated using gold wires. these ultramicroelectrodes were characterized by electrochemical measurements and scanning electron microscopy (sem). electrochemical behavior of the hexacyano ferrate couple using gold ultramicroelectrodes (10 mm diameter) was investigated in a range of different concentrations of kf as supporting electrolyte. the steady state response at a gold ultramicrodisc at different concentrations of hexacyanoferrate couple with high concentrations of electrolyte was utilised to determine the diffusion coefficients of both electroactive species. voltammetric experiments shown, that the oxidation and reduction of this couple is affected by the concentration of the supporting electrolyte. theoretical tafel plots were calculated considering double layer effects and comparisons with the experimental results indicated that determination of the heterogeneous rate constants for the free (unpaired) anions species seems to be imposible. even at lower concentrations and after correction for double layer effects, the reaction is still dominated by ion pair effects.
Application of Different Methods of Surface Analysis for the Early Diagnosis of Art-Stone (Calcarenite) Deterioration
Sabino Bufo
Karaelmas Science and Engineering Journal , 2011, DOI: http://dx.doi.org/10.7212/zkufbd.v1i2.53
Abstract: The deterioration process of historical building is progressive and irreversible, and the timing and mode of impact are different depending on the characteristics of building materials used, local microclimate, air pollution, presence of specific flora and fauna. The surface structural characterisation of building materials is mandatory in preventing and eventually recovering degradation effects. Ideally, the analysis of structural stones should be complete, efficient, rapid, and non destructive when dealing with a precious or unique construction.For this purpose a building sample (ca. 1m3) was constructed by using calcarenite stones (33x15cm), collected from a local quarry, and placed between the archaeological site of Lavello, a little town located in the Basilicata Region (Italy), and the industrial area surrounding this town.In this case study in progress on the degradation of stone materials, we set as an objective the characterization of the state of conservation of stone surfaces.The intact calcarenite stone was characterised by using different methods of surface analysis (XRD, XPS, SEM), and exposed to outdoor conditions. The analyses of the stone material were repeated after three and six months to early evaluate the progression of alterations and the forward modifications of calcarenite structure. Results obtained by using all the applied surface analysis methods were compared. Climatic parameters (temperature, light irradiation, wind intensity, humidity), and air pollutants (SO2, CO, NO2, NO, O3, and heavy metals) were determined. Biological attacks on the surface of calcarenite stones were also investigated.After only three months of the stone sample exposures, the adopted analytical methods were able to provide a series of data, which as in the arrangement of a simple jigsaw puzzle, allowed the assessment of the incipient modification of the stone surfaces confirmed by observations performed on six months replicates, given that climatic conditions and air pollution undermined the structure and the compactness of stones favouring the biological colonization especially in the South–East direction of prevailing winds.
Electrochemical studies of Fe(CN)6(4-)/Fe(CN)6(3-) on gold ultramicroelectrodes varying the concentrations of KF as supporting electrolyte
Sabino Menolasina
Revista Técnica de la Facultad de Ingeniería Universidad del Zulia , 2005,
Abstract: Gold disk ultramicroelectrodes of 10 mum diameter were fabricated using gold wires. These ultramicroelectrodes were characterized by electrochemical measurements and scanning electron microscopy (SEM). Electrochemical behavior of the hexacyano ferrate couple using gold ultramicroelectrodes (10 mum diameter) was investigated in a range of different concentrations of KF as supporting electrolyte. The steady state response at a gold ultramicrodisc at different concentrations of hexacyanoferrate couple with high concentrations of electrolyte was utilised to determine the diffusion coefficients of both electroactive species. Voltammetric experiments shown, that the oxidation and reduction of this couple is affected by the concentration of the supporting electrolyte. Theoretical Tafel plots were calculated considering double layer effects and comparisons with the experimental results indicated that determination of the heterogeneous rate constants for the free (unpaired) anions species seems to be imposible. Even at lower concentrations and after correction for double layer effects, the reaction is still dominated by ion pair effects. Ultramicroelectrodos de oro de 10 mym de diámetro fueron fabricados utilizando alambres de oro. Estos ultramicroelectrodos fueron caracterizados electroquimicamente y utilizando microscopía de barrido electrónico para determinar la forma real de la superficie y obtener información acerca de la calidad del sello entre la interface del metal y el material aislante utilidado en la construcción del electrodo. El comportamiento electroquímico de la pareja redox Fe(CN)6(4-)/Fe(CN)6(3-) fue investigado a diferentes concentraciones del electrolito de soporte KF. Los experimentos realizados por Voltamperometría mostraron que la oxidación y reducción de estas especies son afectadas por la concentración del electrolito de soporte. La velocidad de transferencia electrónica es favorecida al aumentar la concentración del electrolito de soporte. Cálculos teóricos de curvas Tafel tomando en cuenta los efectos de la doble capa fueron realizados y comparados con los resultados experimentales. Estos estudios mostraron que no se puede determinar las constantes de velocidad heterogénea para las especies iónicas no apareadas, debida a que aún a concentraciones muy bajas del electrolito de soporte, la reacción sigue siendo controlada por efectos de par iónico.
Fabrication and characterization of gold ultra and microelectrodes
Sabino Menolasina
Revista Técnica de la Facultad de Ingeniería Universidad del Zulia , 2004,
Abstract: Microelectrodos de oro de 10 y 60 μm de diámetro fueron fabricados utilizando alambres de oro. Estos microelectrodos fueron caracterizados electroquímicamente y utilizando microscopía de barrido electrónico para determinar la forma real de la superficie y obtener información acerca de la calidad del sello entre la interfase del metal y el material aislante utilizado en la construcción del electrodo. Gold disk ultramicroelectrodes of 10 μm and microelectrodes of 60 μm diameter were fabricated using gold wires. These ultra and microelectrodes were characterized by electrochemical measurements and using scanning electron microscopy (SEM) for determining the real shape of the surface, and obtaining information about the quality of the seal at the electrode material-insulating material interface.
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