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OBJECTIVES: This study compared the long-term effects of complete atrioventricular junction (AVJ) ablation with those of AVJ modification in patients with medically refractory atrial fibrillation (AF). BACKGROUND: Comparisons between the long-term effects of AVJ ablation with those of AVJ modification in patients with medically refractory AF have not been systematically studied. METHODS: Sixty patients with medically refractory AF were randomly assigned to receive complete AVJ ablation with permanent pacing or AVJ modification. Subjective perception of quality of life (QOL) was assessed by a semiquantitative questionnaire before and 1 and 6 months after ablation. Cardiac performance was evaluated by echocardiography and radionuclide angiography within 24 h (baseline) and at 1 and 6 months after ablation. RESULTS: Both methods were associated with significant improvement in general QOL and a significant reduction in the frequency of major symptoms and symptoms during attacks. The frequency of hospital admission and emergency room visits and antiarrhythmic drug trials significantly decreased after ablation in both groups. However, patients after complete AVJ ablation had a significantly greater improvement in general QOL and a significantly reduced frequency of major symptoms and symptoms during attacks (including palpitation, dizziness, chest oppression, blurred vision and syncope). Left ventricular (LV) systolic function and the ability to perform activities of daily life significantly improved after ablation in patients with depressed LV function in both groups. All improvements after ablation or modification were maintained over the 6-month follow-up period. CONCLUSIONS: AVJ ablation with permanent pacing, as compared with AVJ modification, had a significantly greater ability to decrease the frequency of attacks and the extent of symptoms of AF, and the patients who received this procedure were more satisfied with their general well-being.  相似文献   
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We analyzed the variability and established the phylogeny of the L1 capsid protein gene of 33 isolates of human papillomavirus type 5 (HPV5) obtained from epidermodysplasia verruciformis patients from different continents. By comparing the sequences of a 419-bp fragment with those published for two Japanese isolates, we found 12.9% variable nucleotide positions, defining 25 variants with mutation rates ranging from 0.2 to 8.8%. Such a high intratypic diversity is unusual among HPVs. Nine of the 139 encoded amino acids were variable and 12 protein variants were identified. Fifteen of the 16 substitutions observed were clustered in two short regions. A 9-amino-acid insert, already reported for the Japanese HPV5b isolate, was found within one of the regions in five isolates. Our data support that the insert arose from the duplication of a 30-nucleotide sequence. Phylogenetic trees distributed the DNA variants into three subtypes (a to c) with a divergence higher than 4.5% and allowed the recognition of European and African lineages. By contrast with the trees based on the HPV5 E6 gene, HPV5a DNA variants and the HPV5b variants lacking the insert constituted a single group in the L1 amino acid tree, probably reflecting different levels of structural constraints for the HPV5 L1 and E6 proteins. In that respect, the short variable L1 sequences should represent less constrained regions.  相似文献   
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BACKGROUND: The epidemic of Human Immunodeficiency Virus (HIV) infection led blood banks to initiate donation deferral criteria based on self-reported risk factors. However little information is available on the differences in reporting risk factors before and after HIV status is known. METHODS: Between April and July 1994, blood donors in a provincial hospital in northern. Thailand were interviewed at the time of donation, about their demographic characteristics and risk factors. All donors had agreed to learn their test results and were called back for post-test counselling and reinterview. RESULTS: HIV-positive blood donors were more likely to change from 'denying' to 'acknowledging' risk factors while HIV-negatives were more likely to change from 'acknowledging' to 'denying'. The differences between risk factors obtained before and after test results were known resulted in stronger, weaker or even opposite risk measures. CONCLUSION: The study results raise questions about the impact of the differences in reporting HIV-related risk factors by the donors on how effective donation deferral criteria can be developed.  相似文献   
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The basic characteristics of a N2-jet system coupled with a surface-ionization type ion source have been investigated at KUR-ISOL. The yields of transported activities and ionized ions have been measured under various conditions for both the He- and N2-jets. The effects of N2 gas upon the ionization and skimmer efficiency have been investigated. It was found that N2 gas has almost no effect upon the ionization efficiency, but causes poorer skimmer efficiency than He gas owing to the large opening angle of aerosol particles at the outlet of a capillary. A mixture of He and N2 gases was also tested.  相似文献   
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The solutions of the diffusion equations with a moving boundary for bubble dissolution (or growth) accompanied by a chemical reaction, were examined. From the viewpoint of the interaction between the convective transport and the chemical reactions, some approximations introduced to solve numerically the equations governing the bubble dissolution (or growth) were studied. For bubble dissolution in glassmelts with equilibrium redox reactions due to refining agents, the applicability of the convection transport approximations employed in the literature was discussed. It was found that our previously proposed model, in which the convective transport is neglected, agrees well with the rigorous finite-difference solution and is more reasonable compared with the approximate models proposed in the literature. Comparisons between our approximate model and the rigorous numerical solution indicate better agreement for dissolution of a bubble by simultaneous mass transfer and chemical reaction, compared with that by only mass transfer. © 1998 Chapman & Hall  相似文献   
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The mixing and mass transfer characteristics in concentric-tube airlift gas-liquid contactors intended for possible use as fermenters are discussed. Liquid velocities, circulation times, gas hold-ups, and volumetric mass transfer coefficients were measured in water and aqueous carboxy methyl cellulose solutions. Measurements were made in an inverted conical-bottom device with draft tubes of three different diameters. An increase of liquid velocities at the column axis and a corresponding decrease of volumetric mass transfer coefficients due to the introduction of draft tubes were found for water as the liquid medium. For the non-Newtonian fluids, a complicating influence of the draft tubes on liquid velocity and mass transfer, which is attributed to a combination of factors related to improvement of liquid circulation and reduction of apparent viscosity, was observed.  相似文献   
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