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91.
92.
BACKGROUND: Dual therapy with ticlopidine and aspirin has been shown to be as effective as or more effective than conventional anticoagulation in patients with an optimal result after implantation of intracoronary metallic stents. However, the safety and efficacy of antiplatelet therapy alone in an unselected population has not been evaluated. METHODS: Patients were randomized to conventional anticoagulation or to treatment with antiplatelet therapy alone. Indications for stenting were classified as elective (decided before the procedure) or unplanned (to salvage failed angioplasty or to optimize the results of balloon angioplasty). After stenting, patients received aspirin and either ticlopidine or conventional anticoagulation (heparin or oral anticoagulant). The primary end point was the occurrence of bleeding or peripheral vascular complications; secondary end points were cardiac events (death, infarction, or stent occlusion) and duration of hospitalization. RESULTS: In 13 centers, 236 patients were randomized to anticoagulation and 249 to antiplatelet therapy. Stenting was elective in 58% of patients and unplanned in 42%. Stent implantation was successfully achieved in 99% of patients. A primary end point occurred in 33 patients (13.5%) in the antiplatelet group and 48 patients (21%) in the anticoagulation group (odds ratio=0.6 [95% CI 0.36 to 0.98], P=0.03). Major cardiac-related events in electively stented patients were less common (odds ratio=0.23 [95% CI 0.05 to 0.91], P=0.01) in the antiplatelet group (3 of 123, 2.4%) than the anticoagulation group (11 of 111, 9.9%). Hospital stay was significantly shorter in the antiplatelet group (4.3+/-3.6 versus 6. 4+/-3.7 days, P=0.0001). CONCLUSIONS: Antiplatelet therapy after coronary stenting significantly reduced rates of bleeding and subacute stent occlusion compared with conventional anticoagulation.  相似文献   
93.
94.
Over the past year, increasing research attention has been devoted to the issue of women at increased risk of developing breast cancer. These articles focus on a range of issues from recruiting high-risk women into breast cancer trials to recommendations for assessment and counseling women with a family history of breast cancer. In addition, continuing research attention has focused on quality of life, symptom management, and articles related to physician-patient communication. This review summarizes and critiques publications in these areas, and it includes articles reviewing the status of research in psychosocial oncology.  相似文献   
95.
Most information about the structures within the brain stem that modulate respiration and sleep are gathered from animal experiments. Therefore we examined 10 patients several weeks after an infarction of the brain stem by means of polysomnography and tested the chemosensitive drives of respiration. None of these patients complained about symptoms of sleep disordered breathing. In each case polysomnographic measurements and ventilatory response curves revealed pathologic findings. The respiratory response to CO2 was diminished or completely abolished in each patient. In some cases hypoventilation or disturbances of the respiratory rhythmicity could be seen. In several cases missing REM sleep, sleep fragmentation or the reduction of slow wave sleep were observed. The study indicates that on the base of results from animal research the comparison of morphological and pathophysiological data is helpful to gain a better understanding on the coupling of the respiratory system with sleep at the brain stem level as well as on the pathomechanism of sleep related breathing disorder.  相似文献   
96.
The electrochemical behaviour of 1024 mild steel electrodes is investigated in the presence of 0.05–0.5 M sodium bicarbonate in aqueous solution at pH 8.9 and 25°C. Voltammograms are obtained with a rotating gold ring-mild steel electrode and the effect of the NaHCO3 concentration, the potential limits and the rotation speed of the disc electrode is considered. The voltammograms display an oxidation peak current at low potentials, a passivity region and a transpassive region at high potentials for the potential sweep in the anodic direction. The oxidation current in the passivity region is practically independent of the applied potential and the NaHCO3 concentration. The rate-determining step of the oxidation reaction in both the oxidation peak current region and the transpassive region is determined.  相似文献   
97.
航空工业中的锻压技术及其发展   总被引:3,自引:0,他引:3  
本文论述了锻压技术在航空工业中的重要作用及其发展;指出了目前应重点发展等温模锻技术、大型锻件的模锻技术、大型风扇叶片的成形及连接技术、锻压过程的物理模拟试验技术和钛合金叶片精锻技术的推广应用等。  相似文献   
98.
研究和讨论了图像质量评估方法,提出一种基于模糊推理的块效应评估标准。假设图像由平滑区域、边缘区域以及纹理区域等组成,而且不同的区域应采用不同的方法进行质量评估。在此基础上,给出了三个分别适用于不同区域的图像质量评估因子,并提出了一个灵活的模糊图像质量评估方法。此方法把块效应和图像本身具有的边缘分开,防止了边缘会被误认为是块效应。仿真结果表明,提出的标准对于不同的图像具有鲁棒性,有一般图像质量评价标准的性能。  相似文献   
99.
In this paper, an evolving least squares support vector machine (LSSVM) learning paradigm with a mixed kernel is proposed to explore stock market trends. In the proposed learning paradigm, a genetic algorithm (GA), one of the most popular evolutionary algorithms (EAs), is first used to select input features for LSSVM learning, i.e., evolution of input features. Then, another GA is used for parameters optimization of LSSVM, i.e., evolution of algorithmic parameters. Finally, the evolving LSSVM learning paradigm with best feature subset, optimal parameters, and a mixed kernel is used to predict stock market movement direction in terms of historical data series. For illustration and evaluation purposes, three important stock indices, S&P 500 Index, Dow Jones Industrial Average (DJIA) Index, and New York Stock Exchange (NYSE) Index, are used as testing targets. Experimental results obtained reveal that the proposed evolving LSSVM can produce some forecasting models that are easier to be interpreted by using a small number of predictive features and are more efficient than other parameter optimization methods. Furthermore, the produced forecasting model can significantly outperform other forecasting models listed in this paper in terms of the hit ratio. These findings imply that the proposed evolving LSSVM learning paradigm can be used as a promising approach to stock market tendency exploration.  相似文献   
100.
Support vector machines (SVM) is an effective tool for building good credit scoring models. However, the performance of the model depends on its parameters’ setting. In this study, we use direct search method to optimize the SVM-based credit scoring model and compare it with other three parameters optimization methods, such as grid search, method based on design of experiment (DOE) and genetic algorithm (GA). Two real-world credit datasets are selected to demonstrate the effectiveness and feasibility of the method. The results show that the direct search method can find the effective model with high classification accuracy and good robustness and keep less dependency on the initial search space or point setting.  相似文献   
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