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1.
To evaluate the effects of long-term treatment antihypertensive with the dihydropyridine calcium antagonist amlodipine on insulin sensitivity, plasma insulin, and lipoprotein metabolism in obese hypertensive patients. We measured the insulin sensitivity index (SI), determined by the Minimal Model Method of Bergman, fasting plasma insulin and glucose concentrations, serum total triglyceride and lipoprotein cholesterol fractions, and blood pressure in 20 obese, non-diabetic patients with essential hypertension before and after 6 weeks of placebo and again after 6 months of amlodipine. Ten patients [mean body mass index (BMI) 30.2 kg.m-2] had been on prior treatment with a thiazide diuretic in low dosage and/or a beta-adrenoceptor blocker (group A), and 10 matched patients [BMI 31.8 kg.m-2] had been previously untreated (group B). Amlodipine was started in a dose of 5 mg and was increased to 10 mg once daily in 14 patients who were hypertensive after 8 weeks on the lower dosage. At entry (before placebo), SI was slightly but not significantly lower in group A than B [2.7 vs. 3.6 x 10(-4) ml.microU-4.min-1]; fasting plasma insulin was 13.6 vs. 12.9 microU.ml-1. After 6 weeks on placebo, S1 averaged 3.7 in group A and 4.4 x 10(-4) microU.ml-1.min-1 in group B; fasting plasma insulin was 14.6 vs. 15.1 microU.ml-1, and glucose 5.5 vs. 5.5 mmol.l-1.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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A novel biodegradable device, designed for long-lasting residual effectiveness of feeding stimulant (sugar) and insecticide (dimethoate) against apple maggot files and other insects, was formulated. The device is an 8-cm diameter fruit-mimicking sphere, consisting of 42-50% sugar entrapped in a mixture of gelatinized corn flour and wheat flour in the presence of glycerin, and coated with a layer of latex paint containing dimethoate and sugar. We found that the outer layer of paint prevents cracking of the sphere upon drying and creates a barrier to control the release of both sugar and dimethoate. Releases of each ingredient were screened first by chemical analysis and then by bioassays in the laboratory and in field cages against apple maggot flies. Chemical analysis demonstrated strong potential for controlled release of water-soluble feeding stimulant and water-insoluble insecticide measured as a function of the amount of rainfall and duration of exposure time. Field results showed greater than 70% insecticidal activity after 11 weeks of sphere exposure in an orchard. This device has the potential to be used for a variety of insect-control applications through manipulating its shape, color and texture into forms known to be attractive to target insects, and by employing various toxicants designed to be effective against such insects.  相似文献   

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BACKGROUND: Indication of liver transplantation for patients infected with hepatitis B virus (HBV) remains controversial because of the high incidence of posttransplant HBV recurrence and aggressive involvement of the allograft. In this article, we provide evidence that the introduction of lamivudine may favorably alter the prognosis of these patients. METHODS: Lamivudine was used in 40 HBV-infected adult patients suffering from chronic end-stage liver disease who underwent liver transplantation. The drug was used in the following settings: failure of prolonged passive immunoprophylaxis, elective conversion from immunoprophylaxis, de novo posttransplant HBV infection, and primary treatment with lamivudine which started before and continued after transplantation. Twenty patients (50%) had viral replication at the time lamivudine was started. Posttransplant and antiviral treatment follow-ups were 8-64 months (median follow-up: 27.5 months) and 9-39 months (median follow-up: 19 months), respectively. RESULTS: The patient and graft survival rates were 97.5% (39/40). Thirty-three patients (82.5%) have remained free of viral recurrence. In the seven re-infected patients, the manifestations of HBV involvement of the allograft have been mild. There have been no side effects related to lamivudine, and the treatment is substantially less costly than with other anti-HBV agents. CONCLUSIONS: Compared with historic series utilizing other modalities of treatment, the use of lamivudine has, so far, yielded superior results. This drug may be an important acquisition for antiviral prophylaxis in HBV-infected liver recipients. Because of the risk of viral mutations, however, efforts should proceed to achieve more efficacious methods for prevention and control of HBV recurrence.  相似文献   

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A field trial to evaluate the efficacy of an oral vaccinia-rabies glycoprotein recombinant virus vaccine in controlling epidemic raccoon (Procyon lotor) rabies was conducted by distributing 180,816 doses (10(8.2)TCID50/ml) of vaccine in wax ampules within fish-meal polymer baits at a rate of 64 doses/km2/treatment throughout a 552 km2 area, forming an 18 km wide band across the northern Cape May Peninsula of New Jersey (USA). Vaccination treatments were conducted in the spring and fall between May 1992 and October 1994 from a helicopter along ecotones and from motor vehicles along roads. Vaccine-laden baits were removed by animals from tracking stations within 3 wk and 61% of the identifiable tracks were those of raccoons. Tetracycline incorporated in the baits as a biomarker was detected in 155 (73%) of the vaccination area raccoons following the fall 1993 and spring 1994 vaccinations. Eleven (61%) of the raccoons sampled in the same time period seroconverted (> or = 0.5 IU) in response to rabies virus glycoprotein. A raccoon diagnosed with rabies from the northern border of the vaccination area on 30 April 1993 provided the first evidence that the barrier was being challenged by the rabies epidemic. The prevalence of rabies in raccoons from the vaccination area for the first year (10%, n = 96) and second year (8%, n = 61) of challenge was reduced more than six-fold by vaccination compared to unvaccinated raccoons from northern adjacent surveillance areas during the corresponding first (65%, n = 189) and second years (53%, n = 43). Vaccination also effectively reduced by three-fold the rate at which the epidemic moved through the raccoon population (15 km/yr). The breach of the vaccination area resulted in a resumption of the high rate (43 km/yr) of epidemic movement and a significant nine-fold increase in rabies prevalence (77%, n = 47). The maximum linear movement (12.9 km) among five ear-tagged rabid raccoons in the study area was significantly greater than that of 19 normal radio-collared raccoons (2.58 km) in the area. These large movements of rabid raccoons, together with relocation of nuisance raccoons, spillover of raccoon rabies in skunks (Mephitis mephitis) and other species, insufficient funding and a decision to discontinue the program in 1994 (which could have resulted in insufficient population immunity among raccoons in the vaccination area) may have contributed to the eventual breach of the barrier.  相似文献   

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Two previously healthy patients were admitted for chest pain, haemoptysis and dyspnoea. Perfusion-ventilation lung scanning demonstrated pulmonary embolism. Lower extremity duplex imaging and contrast venography revealed a thrombosed popliteal vein aneurysm as the source of emboli. After immediate anticoagulant therapy, the thrombo-embolic source was excluded by aneurysmectomy with lateral venography in the first patient. The second patient was treated by anticoagulants and percutaneous vena cava inferior filter placement to prevent recurrent pulmonary embolism. Anatomopathological findings, possible origin, diagnostic modalities and medical and surgical treatment of popliteal vein aneurysm are discussed.  相似文献   

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Needleless connectors have been widely introduced into clinical practice to allow the connection of syringes and luers to peripheral and central vascular catheters. The potential for microbial contamination of catheters via these devices is currently unclear. A recently introduced connector, the 'Connecta Clave', was assessed by various in-vitro methods. The 'Connecta Clave' is specifically devised to separate external components from the fluid pathway. The compression seals of 50 devices were contaminated with 1 x 10(4) cfu Staphylococcus epidermidis, disinfected with isopropanol, and fluid passed through. Only one device allowed organisms to pass through, despite this challenge, representing a contamination rate of 2%. In comparison, when 50 connectors were challenged with 20 cfu of S. epidermidis, no organisms passed through the device during use. In the clinical situation, after manipulation, < 16 cfu of skin organisms were found associated with the compression seal of the devices. It is, therefore, likely that the contamination rates in clinical practice will be extremely low. Three methods of disinfecting the compression seals and associated rims were also evaluated. A combination of alcohol chlorhexidine spray, followed by a 70% isopropanol swab, resulted in the most efficacious disinfection. The isopropanol swabs produced an adequate disinfection rate. The overall results suggest that by use of specially designed connectors, not only are needlestick injuries reduced, but the likelihood of microbial contamination of catheters via the internal route may also be diminished.  相似文献   

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根据炼钢连铸结晶器的特点,设计并实现了便携式结晶器振动监测系统。系统实现了三维振动动画模型的建立、振动频率辨识与计算、振动相位计算、振动幅值及偏差计算和相关工艺参数计算。经过在炼钢厂的现场应用,系统设计满足工业现场的使用要求,能精确地测量结晶器的振动幅值、频率、相位和相关工艺参数,为结晶器的安全生产提供了科学依据,有较好的工程应用价值。  相似文献   

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根据炼钢连铸结晶器的特点,设计并实现了结晶器便携式振动监测系统。采用附加测试件方法消除结晶器表面对信号的影响,提高原始信号质量;通过自适应放大及带通滤波进一步消除干扰信号,提高A/D量化精度;采用多通道同步采样,确保各通道无相移。系统软件具有数据采集与管理、采样组态、测点定义与管理、时域波形显示、波形放大、历史波形回放、历史波形比较、振动相位检测、振动频率检测、报表生成、特征数据采集和振动三维动画显示等功能。  相似文献   

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An ultrasound system has been developed to generate microbubbles in vivo for use as ultrasound contrast agent. Possible application include diagnosis of reflux in the urinary tract. In experiments designed to elucidate the contrast microbubble generation process, acoustic bursts (at 1.8 MHz, 125 ms) were propagated through a latex rubber balloon, modeled after a rabbit urinary bladder, containing fluids of various air and carbon dioxide saturations and concentrations of cavitation nuclei (0.198-micron-diam polystyrene particles). The peak rarefactional pressure threshold for contrast microbubble generation, as visualized with a diagnostic ultrasound system, decreased approximately a factor of 2 for increasing particle concentration from 10(8) to 10(10) particles/cc, with the lowest threshold of 5.24 MPa. For samples with gas saturations below 50% and 10(10) particles/cc, the average thresholds were at least twice as high as those of more saturated fluids (with mean threshold for saturated fluids of 6.45 MPa), and samples containing CO2 had considerably lower thresholds than respective under-saturations in air. At a fixed pressure amplitude, echogenicity tended to increase with both increasing particle concentration and gas saturation; this was more favorable for samples containing CO2. Even in a restricted-nuclei environment such as the urinary bladder, generation of vaporous cavitation should be possible; however, subsequently, abundant gas is needed to grow vaporous bubbles to persistent and imageable sizes, to assist in the diagnosis of urinary reflux.  相似文献   

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This article examines the claim that the learning of a dynamic control task is mediated by a lookup table consisting of previously successful trials on the task. Consistent with the predictions of a lookup table, in 2 experiments participants tended to give the same response to situations in which they had previously been successful rather than unsuccessful. Further, in both experiments, participants' knowledge did not generalize to new dissimilar situations, unless the dynamic control task was governed by a highly salient rule. A version of G. Logan's (1988) instance theory, which assumes that participants store each successful response as a separate instance linking the situation to the response, was able to quantitatively match a range of measures of participants' performance with 1 free parameter, except in the case in which the control task was governed by a salient rule. In a complementary way, an alternative rule-based model could only match participants' performance when the control task was governed by a highly salient rule. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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介绍基于STC12C5A60S2单片机的便携式里氏硬度计的研究与设计,详细介绍了里氏硬度计的设计原理、硬件结构图、实现里氏硬度测量的主程序流程,同时,给出了部分程序代码和实际的测试数据.  相似文献   

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《Acta Metallurgica Materialia》1990,38(11):2353-2355
A reciprocating marmen engine has been devised and built. Examination of stills from cine films of the engine executing its piston-like action have enabled measurements to be made of the times for heat transfer into, and from, the working elements.  相似文献   

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In article the questions about modernization of portable equipment for rendering the first, medical and the first medical qualified care to the wounded and injured on the battle field and at the stages of medical evacuation are analyzed. The problems of creation of portable equipment for the medical specialists for rendering the urgent care to the injured and patients outside of medical establishments in peace time are considered. Development, carried out by the authors, have allowed to improve equipment of the medical service personnel.  相似文献   

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OBJECTIVES: To validate the results of the home penile tumescence monitor versus the sleep laboratory studies of erectile function. METHODS: We used both methods to study 18 episodes of rigidity and 19 episodes of tumescence in 10 subjects with erectile dysfunction before and after the use of an experimental vasodilating medication. RESULTS: The tumescence measurement in the sleep laboratory compared favorably with the changes in tumescence with the RigiScan portable home monitor: at the base (r = 0.70; P < 0.001), and at the tip (r = 0.84; P < 0.001). In measuring rigidity, the buckling pressure in the sleep laboratory compared favorably with the RigiScan measurements of percent average rigidity at the base (r = 0.56; P = 0.017), at the tip (r = 0.62; P = 0.006), and mean rigidity of the base and tip (r = 0.64; P = 0.004). In a comparison of the buckling pressure with the new RigiScan Plus quantitative program, there was good correlation with the rigidity activity units at the base (r = 0.70; P = 0.001) and at the tip (r = 0.72; P < 0.001). A clinical estimate of penetrable rigidity correlates with the RigiScan base rigidity of 55% to 60% and tip rigidity of about 50%. CONCLUSIONS: The portable home monitor is a viable and cost-effective clinical tool to measure nocturnal penile activity.  相似文献   

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