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981.
ZUO Zhi-gang LI Sheng-cai School of Engineering University of Warwick Coventry CV AL UK LIU Shu-hong 《水动力学研究与进展(B辑)》2009,21(2):152-158
In order to further verify the proposed theory of cavitation resonance, as well as to proceed the investigations into microscopic level, a series of studies are being carried out on the Warwick venturi. The analysis of the oscillation characteristics of the cavitation resonance has conclusively verified the macro-mechanism proposed through previous studies on other cavitating flows by the authors. The initial observations using high-speed photographic approach have revealed a new attribution of cavitation resonance. That is, the volumetric oscillation of cavitation cloud is associated with the cavitation resonance, which is a collective behaviour of the bubbles in the cloud. 相似文献
982.
Our study is to demonstrate the advantages and disadvantages of middle cerebral artery occlusion (MCAO) model in the mouse. CD-1 mice had permanent MCAO for 24 h, or temporary occlusion for either 1 h followed by 23 h of reperfusion or 2 h of occlusion with 22 h of reperfusion. The infarct volume and blood-brain barrier disruption were smaller in the 1-h/23-h temporary occlusion than in either the 24-h permanent occlusion group or the 2-h/22-h temporary occlusion group (p<0.05). Our study demonstrates that blood flow, infarct volume, and blood-brain barrier disruption remain important markers of focal cerebral ischemia. 相似文献
983.
To generate a useful strategy for mucosal immunization, we have developed an approach of lipidating a multiple Ag peptide (MAP) containing part of the V3 loop from HIV-1 gp120IIIB. In this work, we compare two delivery systems, lipidated MAP in PBS and encapsulation in poly(DL-lactide-co-glycolide) microparticles. Subcutaneous immunization, followed by intragastric administration of MAP peptide entrapped or not entrapped in microparticles, induced mucosal and systemic immune responses at local and distant sites, including mucosal IgA in saliva, vaginal secretions and feces, and IgG in blood. However, lipidated Ag delivered in microparticles induced higher levels of mucosal Abs, particularly of intestinal IgA, and generated CTL responses. In contrast, lipidated MAP delivered by nasal route microparticles was less effective in inducing CTL responses. These results demonstrate the feasibility of using a lipidated multimeric peptide for mucosal immunization to stimulate both systemic and mucosal immune systems, including the genital tract, irrespective of the route or method of delivery and without requiring the use of a carrier or an extraneous adjuvant. 相似文献
984.
Two investigational vaccines, TC-83 (live-attenuated) and C-84 (formalin-inactivated), are currently available to immunize at-risk individuals against Venezuelan equine encephalitis virus (VEE). Ideally, such vaccines should protect against both the natural mosquito-borne route of infection and from aerosol, the most common route of laboratory infection. Whereas considerable data on vaccine efficacy following parenteral challenge are available, the efficacy of these vaccines against disease caused by aerosol exposure is not well established in primates. We compared the immunogenicity and protective capacity of TC-83 and C-84 against either subcutaneous or aerosol routes of infection in cynomolgus monkeys implanted with temperature-monitoring radiotelemetry devices. A single s.c. dose of TC-83, or three s.c. doses (days 0, 7, 28) of C-84, elicited similar serum virus-neutralizing antibody responses. Animals immunized with either TC-83 or C-84 were protected against s.c. infection. In contrast, after aerosol infection, 40% of the animals vaccinated with either TC-83 or C-84 developed signs nearly as severe as those seen in unvaccinated animals. Protection was not entirely consistent with the measured preinfection immune responses: unprotected animals had serum virus-neutralizing antibody titers and lymphoproliferative responses similar to those seen in protected animals. In this study, C-84 (three doses) protected monkeys as well as TC-83 (one dose) against either a s.c. or aerosol VEE challenge. 相似文献
985.
VI Shumski? AI Koval'kov AL Roslov VA Denisov GL Sachechelashvili 《Canadian Metallurgical Quarterly》1992,(3):23-27
Recurrent or residual choledocholithiasis was diagnosed in 202 patients with a history of cholecystectomy, in 148 cases this condition was combined with papillostenosis. Transfistula extraction of the concrements and endoscopic papillosphyncterotomy helped achieve cure of 186 (92%) patients without relaparotomy. The authors discuss the role of roentgenology in such combined x-ray and endoscopic diapedetic examinations and emphasize its role in identification of the diagnostic details that are so important for the choice of the optimal treatment strategy. They come to a conclusion that the results of treatment of complicated cholelithiasis by 'minor surgery' means depend not only on the manipulations and skills of the surgeon endoscopist, but on the full-value employment of roentgenology as well. 相似文献
986.
HJ Wellens CP Lau B Lüderitz M Akhtar AL Waldo AJ Camm C Timmermans HF Tse W Jung L Jordaens G Ayers 《Canadian Metallurgical Quarterly》1998,98(16):1651-1656
BACKGROUND: During atrial fibrillation, electrophysiological changes occur in atrial tissue that favor the maintenance of the arrhythmia and facilitate recurrence after conversion to sinus rhythm. An implantable defibrillator connected to right atrial and coronary sinus defibrillation leads allows prompt restoration of sinus rhythm by a low-energy shock. The safety and efficacy of this system, called the Atrioverter, were evaluated in a prospective, multicenter study. METHODS AND RESULTS: The study included 51 patients with recurrent atrial fibrillation who had not responded to antiarrhythmic drugs, were in New York Heart Association Heart failure class I or II, and were at low risk for ventricular arrhythmias. The atrial defibrillation threshold had to be =240 V during preimplant testing. Atrial fibrillation detection, R-wave shock synchronization, and defibrillation threshold were tested at implantation and during follow-up. Shock termination of spontaneous episodes of atrial fibrillation was performed under physician observation. Results are given after a minimum of 3 months of follow-up. During a follow-up of 72 to 613 days (mean, 259+/-138 days), 96% of 227 spontaneous episodes of atrial fibrillation in 41 patients were successfully converted to sinus rhythm by the Atrioverter. In 27% of episodes, several shocks were required because of early recurrence of atrial fibrillation. Shocks did not induce ventricular arrhythmias. Most patients received antiarrhythmic medication during follow-up. In 4 patients, the Atrioverter was removed: in 1 because of infection, in 1 because of cardiac tamponade, and in 1 because of frequent episodes of atrial fibrillation requiring His bundle ablation. CONCLUSIONS: With the Atrioverter, prompt and safe restoration of sinus rhythm is possible in patients with recurrent atrial fibrillation. 相似文献
987.
988.
PURPOSE: Optimization of image quality by use of digital luminescence radiography (DLR) in voiding cystoureterography (VCU) instead of a conventional screen film system. PATIENTS AND METHODS: 53 patients with a suspected vesicouretral reflux were examined with a VCU in analogous and digital technique. The X-rays were taken in a sitting position while simultaneously measuring the bladder pressure. An intraindividual comparison was omitted for X-ray saving reasons. In the follow-up 3 patients were examined with the other system. Two radiologists and two urologists compared 60 VCU of 53 patients--30 VCU in conventional screen film and 30 in DLR technique presented in standard and edge-enhanced images--with regard to image quality according to 3-step score (A--good image quality, B--sufficient image quality, C--insufficient image quality). RESULTS: The 59 conventional films were scored 72 times with an A, 76 times with a B, and 72 times with a C, whereas the DLR films were scored 116 times with an A, 72 times with a B, and only 8 times with a C. Hereby the edge-enhanced images were the most useful for distinguishing the bladder shadow from the soft tissue of the thigh and for detecting reflux. Furthermore, the exposure dose when applying DLR could be decreased to 75% in grown-ups and to 57% in children without any significant loss of information. CONCLUSION: The DLR is highly superior to the conventional film screen system because of its relatively high tolerance towards wrong exposures, especially with respect of the sitting position during MCU. With the DLR we obtained 96% and with the conventional system only 63% films usable for diagnosis. 相似文献
989.
ME Mackenzie WT Davies MB Farnell AL Weaver DM Ilstrup 《Canadian Metallurgical Quarterly》1996,131(10):1083-1085
OBJECTIVE: To determine if the presence of duodenal diverticula predisposes to the development of common bile duct stones. DESIGN: Cohort study; median follow-up, 10.0 years (25th and 75th percentiles, 5.2 and 16.1 years, respectively). SETTING: Tertiary care center. PATIENTS: One hundred fifty-seven patients with radiologically diagnosed duodenal diverticula who had undergone cholecystectomy from 1950 through 1987 and were asymptomatic at the initiation of follow-up. MAIN OUTCOME MEASURES: All patients were followed up for evidence of recurrent biliary tract disease to the following end points: (1) evidence of choledocholithiasis demonstrated by radiologic surgical, or biochemical means and (2) clinical or biochemical evidence of biliary pancreatitis. RESULTS: Of the 157 patients in the study cohort, 13 patients were categorized as having had recurrent biliary tract disease. Using the Kaplan-Meier survivorship method, the cumulative probabilities of recurrent biliary tract disease in patients with radiologically diagnosed duodenal diverticula were 3.6% at 5 years (95% confidence interval, 0.5-6.9), 5.5% at 10 years (95% confidence interval, 1.5-9.4), and 10.2% at 15 years (95% confidence interval, 3.8-16.7). Age, common bile duct exploration and choledochotomy, and the presence of common bile duct dilatation were not found to be significantly associated with recurrence based on a univariate analysis of risk factors by means of the log-rank statistic. CONCLUSIONS: For patients with radiologically diagnosed, second-portion duodenal diverticula, the risk of developing recurrent bile duct stones after cholecystectomy is lower than has been suggested in previous studies. In the absence of concurrent choledocholithiasis, sphincterotomy or biliary bypass at the time of cholecystectomy seems unwarranted. 相似文献
990.