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   17979篇
  免费   1960篇
  国内免费   189篇
耳鼻咽喉   141篇
儿科学   531篇
妇产科学   298篇
基础医学   2485篇
口腔科学   614篇
临床医学   1913篇
内科学   3434篇
皮肤病学   176篇
神经病学   2107篇
特种医学   656篇
外科学   2542篇
综合类   466篇
一般理论   30篇
预防医学   1830篇
眼科学   457篇
药学   1298篇
  1篇
中国医学   39篇
肿瘤学   1110篇
  2021年   222篇
  2020年   159篇
  2019年   267篇
  2018年   253篇
  2017年   245篇
  2016年   264篇
  2015年   287篇
  2014年   435篇
  2013年   628篇
  2012年   880篇
  2011年   1052篇
  2010年   543篇
  2009年   475篇
  2008年   875篇
  2007年   938篇
  2006年   881篇
  2005年   893篇
  2004年   827篇
  2003年   833篇
  2002年   826篇
  2001年   563篇
  2000年   624篇
  1999年   505篇
  1998年   292篇
  1997年   268篇
  1996年   256篇
  1995年   189篇
  1994年   186篇
  1993年   184篇
  1992年   370篇
  1991年   324篇
  1990年   358篇
  1989年   292篇
  1988年   336篇
  1987年   281篇
  1986年   259篇
  1985年   245篇
  1984年   202篇
  1983年   177篇
  1982年   156篇
  1981年   151篇
  1980年   146篇
  1979年   190篇
  1978年   140篇
  1977年   123篇
  1976年   117篇
  1975年   95篇
  1974年   127篇
  1973年   118篇
  1972年   99篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Clinical Rheumatology - Prof. Ari Polachek on of the author of the published version of this article missed to add his second affiliation which is the Department of Rheumatology, Tel Aviv Sourasky...  相似文献   
5.
6.
7.
PURPOSE: Few published studies have addressed individual patient risk after R0 resection for gastric cancer. We developed and internally validated a nomogram that combines these factors to predict the probability of 5-year gastric cancer-specific survival on the basis of 1,039 patients treated at a single institution. METHODS: Nomogram predictor variables included age, sex, primary site (distal one-third, middle one-third, gastroesophageal junction, and proximal one-third), Lauren histotype (diffuse, intestinal, mixed), number of positive lymph nodes resected, number of negative lymph nodes resected, and depth of invasion. Death as a result of gastric cancer was the predicted end point. The concordance index was used as an accuracy measure, with bootstrapping to correct for optimistic bias. Calibration plots were constructed. RESULTS: Gastric cancer-specific survival at 5 years was 50%. A nomogram was constructed on the basis of a Cox regression model. The bootstrap-corrected concordance index was 0.80. When compared with the predictive ability of American Joint Committee on Cancer stage, the nomogram discrimination was superior (P <.001). Nomogram calibration appeared to be excellent. CONCLUSION: A nomogram was developed to predict 5-year disease-specific survival after R0 resection for gastric cancer. This tool should be useful for patient counseling, follow-up scheduling, and clinical trial eligibility determination.  相似文献   
8.
Development of the New Lung Allocation System in the United States   总被引:2,自引:2,他引:0  
This article reviews the development of the new U.S. lung allocation system that took effect in spring 2005. In 1998, the Health Resources and Services Administration of the U.S. Department of Health and Human Services published the Organ Procurement and Transplantation Network (OPTN) Final Rule. Under the rule, which became effective in 2000, the OPTN had to demonstrate that existing allocation policies met certain conditions or change the policies to meet a range of criteria, including broader geographic sharing of organs, reducing the use of waiting time as an allocation criterion and creating equitable organ allocation systems using objective medical criteria and medical urgency to allocate donor organs for transplant. This mandate resulted in reviews of all organ allocation policies, and led to the creation of the Lung Allocation Subcommittee of the OPTN Thoracic Organ Transplantation Committee. This paper reviews the deliberations of the Subcommittee in identifying priorities for a new lung allocation system, the analyses undertaken by the OPTN and the Scientific Registry for Transplant Recipients and the evolution of a new lung allocation system that ranks candidates for lungs based on a Lung Allocation Score, incorporating waiting list and posttransplant survival probabilities.  相似文献   
9.
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects.  相似文献   
10.
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community.  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