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71.
IM Robbins EV Colvin TP Doyle WE Kemp JE Loyd WS McMahon GN Kay 《Canadian Metallurgical Quarterly》1998,98(17):1769-1775
BACKGROUND: This report describes the complication of pulmonary vein stenosis with resultant severe pulmonary hypertension that developed in 2 patients after successful catheter ablation of chronic atrial fibrillation. METHODS AND RESULTS: Three months after successful catheter ablation of atrial fibrillation, both patients developed progressive dyspnea and pulmonary hypertension. Both were found to have severe stenosis of all 4 pulmonary veins near the junction with the left atrium. Balloon dilation of the stenotic pulmonary veins was performed in these patients, with improvement in dyspnea and pulmonary hypertension. CONCLUSIONS: The complication of pulmonary vein stenosis is potentially life-threatening, and the application of radiofrequency current within the pulmonary veins with standard catheter technology should be avoided. This complication can be treated with balloon dilation, although the long-term course is unknown. 相似文献
72.
Qualitative and quantitative characteristics of chronic pain syndrome and their possible use in assessing analgetic effects of treatment were studied in 16, 49, 26 and 17 patients with gastric ulcer, duodenal ulcer, chronic pancreatitis, chronic colitis, respectively. Pain was measured with the use of McHill's questionnaire modification and visual-verbal-analog scale. In addition to routine analysis of the data from the respondents, graphic mean profiles of pain for each group have been devised. There were differences in quantitative parameters of pain syndrome depending on nosological unity and profiles of patients. The questionnaire proved rather informative in evaluation and gradation of analgetic effects of therapeutic factors in ulcer patients. 相似文献
73.
It is known that drugs are not unlimitedly stable. Dilutions of the antineoplastic agent daunoblastin used in the clinic and experimental work, were examined, whether they could be stored for several days. By means of impulscytophotometry, spectral-photometric measurements, counting of surviving cells and estimation of DNA-synthesis after culturing pieces of tissue in the presence of daunoblastin it could be established that this drug, diluted even four days ago, still possesses sufficient activity. 相似文献
74.
75.
A preview tracking task has been developed which has particular application to neurological assessment and rehabilitation. Generated and monitored by a graphic display computer, it permits accurate global quantification of the upper-limb sensory-motor system. The incorporation of 'preview' into the tracking task is considered to significantly increase its effectiveness and relevance in relation to normal daily activities. Applied to three groups of normal subjects, several features of normal psychomotor performance and learning were identified or verified: hand dominance is not significant in overall arm control; learning does not completely plateau; increase in age (15-59 years) results in only a minor overall decrement in performance; an initial wide performance distribution decreases dramatically in subsequent sessions. Applied to brain-damaged patients, particularly head injury or stroke, the preview tracking task allows assessment at regular intervals enabling sensory-motor recovery curves to be generated. The potential of this technique, to help determine the efficacy of therapeutic procedures on the recovery process, is illustrated with the presentation of results from three brain-damaged patients demonstrating zero, significant and disjointed recovery of sensory-motor function. The usefulness of the preview tracking task can be expanded by combination with a less frequently applied but more component specific neurological assessment battery. 相似文献
76.
Hsing Kenneth?ChengEmail author Haluk?Demirkan Gary J.?Koehler 《Information Systems and E-Business Management》2003,1(3):305-329
In this paper, we study the price and capacity competition of two application service providers (ASPs). The customers realize an intrinsic time-independent value from transactions processed by the ASP. The cost to the customers includes both the price charged by the ASP and the delay cost due to turnaround time of the ASP service system. Customers will choose to join the ASP who delivers a higher net value of the service. This paper examines the competition between two ASPs and the impact of customers' delay cost on ASP's pricing and capacity decisions. We find that the ASP with higher capacity will charge a higher price and enjoy a larger market share and, surprisingly, that customers' delay cost has no direct impact on the arrival rates to the ASPs but affects the ASPs' pricing decisions. The ASPs will charge a higher price premium to capitalize customers' higher delay cost. For the long-run problem, we find that in the presence of higher customer's delay cost, both ASPs' optimal profits suffer, in contrast to the short-run problem where a higher customer's delay cost leads to a higher profitability for both ASPs. 相似文献
77.
水解淫羊藿苷糖基的土壤细菌筛选 总被引:1,自引:0,他引:1
从20种土壤细菌中筛选出了对淫羊藿苷水解能力高的菌株Rhodanobncter sp.GS3054.该菌株30℃下发酵3~4d的发酵液提酶后对淫羊藿苷水解能力最佳;水解淫养藿苷成低糖基苷的最适反应条件为:50℃、pH6.0、底物20mg/mL,反应时间24h. 相似文献
78.
Kil-Sung LEE Hyeon-Kyeong SEO Yong-June YANG Woo-Chae HWANG Kwang-Hee IM In-Young YANG 《中国有色金属学会会刊》2011,(Z1):135-140
The recent trend of vehicle design aims at crash safety and environmentally-friendly aspect. For the crash safety aspect, the energy absorbing members should absorb collision energy sufficiently but for the environmentally-friendly aspect, the vehicle structure must be light weight in order to improve the fuel efficiency and reduce the tail gas emission. Therefore, the light weight of vehicle must be achieved in a securing safety status of crash. An aluminum or carbon fiber reinforced plastics (CFRP) is rep... 相似文献
79.
AM Castellino P Cantalupo IM Marks JV Vartikar KW Peden JM Pipas 《Canadian Metallurgical Quarterly》1997,71(10):7549-7559
Simian virus 40 (SV40) DNA replication requires the coordinated action of multiple biochemical activities intrinsic to the virus-encoded large tumor antigen (T antigen). We report the preliminary biochemical characterization of the T antigens encoded by three SV40 mutants, 5030, 5031, and 5061, each of which have altered residues within or near the ATP binding pocket. All three mutants are defective for viral DNA replication in cultured cell lines. However, while 5030 and 5031 can be complemented in vivo by providing a wild-type T antigen in trans, 5061 exhibits a strong trans-dominant-negative phenotype. In order to determine the basis for their replication defects and to explore the mechanisms of trans dominance, we purified the T antigens encoded by each of these mutants and examined their activities in vitro. The 5061 T antigen had no measurable ATPase activity and failed to hexamerize in response to ATP, and its affinity for the SV40 origin of DNA replication (ori) DNA was not increased by ATP. In contrast, the 5030 and 5031 T antigens exhibited at least some ATPase activity and both readily formed hexamers in the presence of ATP. These mutants differed in that 5030 was very defective in an ori-dependent unwinding assay while 5031 retained significant activity. Both the 5030 and 5031 T antigens bound to ori-containing DNA, but the binding was less efficient than that of wild-type T antigen and was not affected by the presence of ATP. These results suggest that 5030 and 5031 are defective in some aspect of communication between the ATP binding and DNA binding domains and that the ability of ATP to induce T-antigen hexamerization is distinct from its action to increase the affinity for ori. Finally, all three mutants were defective for the ability to support SV40 DNA replication in vitro. Both the 5031 and 5061 T antigens inhibited wild-type-T-antigen-stimulated replication in vitro, while the 5030 T antigen did not. The fact that the 5031 T antigen was trans dominant in the in vitro assays but not in vivo indicates that the in vitro system does not accurately reflect events occurring in vivo. 相似文献
80.
Donald L. Smith Andrew S. Alimonda Chau-Chen Chen Hsing C. Tuan 《Journal of Electronic Materials》1990,19(1):19-27
The high rate of charge trapping in thin-film silicon nitride causes its electrical properties to change with stressing level
and time. The rate of shift of the high-frequency CV curves of Al/SiNxHy/cSi capacitors was used here to measure nitride charging rate and to compare PECVD nitrides deposited under various conditions
of plasma power and gas mixture in the same parallel-plate reactor. By operating the plasma under high power to activate the
NH3 or N2 and under low SiH4 flow to ensure that all of the SiH4 reacts with N, it is possible to deposit N-rich nitride that has no detectable Si—H bonding,
which bonding others have correlated with charge trapping. Nitride deposited under these conditions using NH3 and 13 MHz rf power had charging rates for both gate polarities that were 20 times lower than those of nitride that had a
“stoichiometric” N/Si ratio of 4/3 and that had its H distributed among Si—H and N—H bonds. MIS capacitors made with the latter
nitride also had a high negative initial flat-bond voltage, indicating the presence of grown-in positive charge. This charge
was large enough to invert the surface ofp-Si substrates. N-rich nitride free of Si—H that was deposited either using N2 or using low-frequency rf power (≤400 kHz) had higher charging rates than did that deposited from NH3 at 13 MHz. Also, the low-frequency material contained grown-in positive charge that is attributed to H+ implanted by the high ion bombardment energy of the low-frequency plasma. 相似文献