首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6173篇
  免费   306篇
  国内免费   16篇
耳鼻咽喉   99篇
儿科学   408篇
妇产科学   73篇
基础医学   579篇
口腔科学   101篇
临床医学   417篇
内科学   1388篇
皮肤病学   178篇
神经病学   357篇
特种医学   194篇
外科学   1047篇
综合类   130篇
一般理论   3篇
预防医学   269篇
眼科学   299篇
药学   457篇
中国医学   18篇
肿瘤学   478篇
  2023年   47篇
  2022年   65篇
  2021年   226篇
  2020年   106篇
  2019年   139篇
  2018年   182篇
  2017年   127篇
  2016年   134篇
  2015年   160篇
  2014年   232篇
  2013年   275篇
  2012年   440篇
  2011年   457篇
  2010年   273篇
  2009年   188篇
  2008年   335篇
  2007年   348篇
  2006年   342篇
  2005年   329篇
  2004年   281篇
  2003年   232篇
  2002年   218篇
  2001年   96篇
  2000年   70篇
  1999年   81篇
  1998年   51篇
  1997年   43篇
  1996年   41篇
  1995年   39篇
  1994年   25篇
  1993年   27篇
  1992年   87篇
  1991年   63篇
  1990年   49篇
  1989年   62篇
  1988年   49篇
  1987年   43篇
  1986年   52篇
  1985年   41篇
  1984年   34篇
  1983年   21篇
  1981年   21篇
  1979年   33篇
  1977年   20篇
  1976年   33篇
  1975年   23篇
  1972年   21篇
  1971年   23篇
  1970年   28篇
  1969年   27篇
排序方式: 共有6495条查询结果,搜索用时 31 毫秒
1.
2.
3.
A 65-year-old man developed acute limb ischemia, severe abdominal wall and lower limb livedo reticularis following a coronary angiogram. The differential diagnoses of acute limb ischemia and multiple cholesterol emboli syndrome (MCES) are discussed. This work was performed at Long Island Jewish Medical Center, 270-05, 76th Avenue, New Hyde Park, NY 11040.  相似文献   
4.
Forty-nine cases of gastroduodenal perforation were subjected to new air insufflation test. The clinical and radiological criteria of air insufflation test were applied to every patient of this study. Forty-seven cases (95.9%) were positive to the new test whereas 2 negative cases turned out to be old sealing perforation. The new test is highly useful in preoperative detection of site of perforation in perforative peritonitis.  相似文献   
5.
6.
O P Khanna  J H Loose 《Urology》1990,36(2):139-142
Three patients with interstitial cystitis diagnosed on the basis of clinical symptoms, classic endoscopic findings, and a typical histologic picture were treated with intravesical doxorubicin. All 3 patients showed remarkable improvement, as manifested by complete clearance of irritative bladder symptoms and healing of ulceration. Doxorubicin therefore may be the breakthrough drug for interstitial cystitis.  相似文献   
7.
8.
This is a prospective, non-randomized study to evaluate and compare the results, morbidity and surgical time for endonasal carbon-dioxide laser assisted dacryocystorhinostomy and external dacryocystorhinostomy. 70 consecutive patients of chronic dacryocystitis with nasolacrimal duct obstruction were selected for the study. 36 patients under went endonasal CO2 laser assisted dacryocystorhinostomy and 34 had external dacryocystorhinostomy. Selection of the type of operation was left to the patient's choice. All the patients had preoperative counseling and both the procedures were explained in detail with their advantages and disadvantages. Patients not willing for the external incision were selected for endonasal laser assisted dacryocystorhinostomy and others were operated via external approach. Silicone tubes were put in all the patients for three months after surgery. The final follow up was 12 months after the removal of silicone tubes. The patency of the lacrimal passage was confirmed by irrigation, and patients were questioned about their symptoms. The success rates, 12 months after removal of silicone tubes were 100% in endonasal CO2 laser assisted dacryocystorhinostomy and 88.24% in external dacryocystorhinostomy. The surgical time of endonasal laser assisted dacryocystorhinostomy was 38 minutes as compared to 62 in external dacryocystorhinostomy. Complication rate in both groups was almost equal. Thus, we came to the conclusion that Endonasal CO2 laser assisted dacryocystorhinostomy is a better surgical option to external dacryocystorhinostomy in cases of chronic dacryocystitis with nasolacrimal duct obstruction, with shorter surgical time.  相似文献   
9.
Measuring the efficacy of antiepileptic drugs.   总被引:4,自引:0,他引:4  
Clinical trials of new antiepileptic drugs (AEDs) include regulatory studies aimed at demonstrating efficacy and reasonable safety, post-marketing open-open label studies and longer term outcome studies. Regulatory trials involve a carefully selected population of patients and are conducted under rigorously standardised conditions. Data from such studies cannot often be translated into clinical practice. Pragmatic post-marketing studies using flexible dosing schedules allow clinicians to better judge the utility of the new drug in a wider population of patients with epilepsy and decide the most appropriate dosing schedules. This paper discusses some of the issues surrounding the measurement of efficacy of new AEDs in both pre- and post-marketing phases of their development. All of the newer AEDs are initially used in patients with refractory partial seizures as adjunctive treatment. These trials are generally parallel-group studies although cross-over designs have been employed. The use of placebo-control is uncontroversial in this type of study. Efficacy endpoints are generally manipulations of seizure frequency on study drug compared to control. Global outcome measures and health related quality of life scores can also be used to measure efficacy. As the standard AEDs are associated with a high rate of seizure remission in patients who receive them as monotherapy, demonstration of superior efficacy of a new agent in a comparative trial will require large numbers of patients in a design that takes into account the natural history of treated epilepsy. Comparing investigational agents to a standard AED in an 'active-control' study with demonstration of equivalent efficacy would seem to be an acceptable way of assessing efficacy of new AEDs in this population. Some regulators, however, do not accept equivalence as proof of efficacy and insist on demonstration of superiority compared to a control. The use of placebo alone in the control group is ethically dubious. Several innovative study designs have, therefore, been used to satisfy regulatory requirements, while maintaining patient safety including withdrawal to monotherapy using high versus low dose comparators. Observational outcome studies provide the best opportunity of exploring the long-term utility of individual AEDs. Such studies largely follow standard clinical practice and need considerable time and resources. They can, however, yield valuable information about the effectiveness of AEDs in everyday clinical practice. Data from regulatory trials should be complemented by postmarketing studies and longer term studies of outcome to help clinicians decide the best way of utilising new AEDs and establishing their role in the therapeutic armamentarium.  相似文献   
10.
Physiological analysis to quantify training load in badminton.   总被引:2,自引:1,他引:1       下载免费PDF全文
OBJECTIVE: To estimate the training load of specific on court training regimens based on the magnitude of variation of heart rate-lactate response during specific training and to determine the magnitude of variation of biochemical parameters (urea, uric acid, and creatine phosphokinase (CPK)) 12 hours after the specific training programme so as to assess training stress. METHODS: The study was conducted on six national male badminton players. Maximum oxygen consumption (VO2), ventilation (VE), heart rate, and respiratory quotient were measured by a protocol of graded treadmill exercise. Twelve training sessions and 35 singles matches were analysed. Heart rate and blood lactate were monitored during technical training routines and match play. Fasting blood samples collected on two occasions--that is, during off season and 12 hours after specific training--were analysed for serum urea, uric acid, and CPK. RESULTS: Analysis of the on court training regimens showed lactate values of 8-10.5 mmol/l in different phases. The percentage of maximum heart rate ranged from 82% to 100%. Urea, uric acid, and CPK activity showed significant changes from (mean (SD)) 4.93 (0.75) mmol/l to 5.49 (0.84) mmol/l, 0.23 (0.04) to 0.33 (0.06) mmol/l, and 312 (211.8) to 363 (216.4) IU/l respectively. CONCLUSION: Maximum lactate reported in the literature ranges from 3-6 mmol/l. Comparatively high lactate values and high percentage of maximum heart rate found in on court training show a considerable stress on muscular and cardiovascular system. The training load needs appropriate monitoring to avoid over-training. Workouts that are too intensive may interfere with coordination, a factor that is important in sports requiring highly technical skill such as badminton.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号