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   57172篇
  免费   3604篇
  国内免费   112篇
耳鼻咽喉   535篇
儿科学   2341篇
妇产科学   1542篇
基础医学   7154篇
口腔科学   563篇
临床医学   8793篇
内科学   9808篇
皮肤病学   796篇
神经病学   5544篇
特种医学   1007篇
外科学   4760篇
综合类   614篇
一般理论   112篇
预防医学   7937篇
眼科学   770篇
药学   3752篇
中国医学   61篇
肿瘤学   4799篇
  2023年   304篇
  2022年   473篇
  2021年   1093篇
  2020年   734篇
  2019年   1117篇
  2018年   1265篇
  2017年   1019篇
  2016年   1100篇
  2015年   1289篇
  2014年   1762篇
  2013年   2815篇
  2012年   4002篇
  2011年   4324篇
  2010年   2380篇
  2009年   2164篇
  2008年   3900篇
  2007年   4131篇
  2006年   3989篇
  2005年   4118篇
  2004年   3925篇
  2003年   3693篇
  2002年   3399篇
  2001年   507篇
  2000年   389篇
  1999年   496篇
  1998年   695篇
  1997年   623篇
  1996年   486篇
  1995年   491篇
  1994年   432篇
  1993年   340篇
  1992年   277篇
  1991年   229篇
  1990年   218篇
  1989年   232篇
  1988年   202篇
  1987年   188篇
  1986年   182篇
  1985年   190篇
  1984年   205篇
  1983年   178篇
  1982年   220篇
  1981年   217篇
  1980年   160篇
  1979年   103篇
  1978年   120篇
  1977年   63篇
  1976年   58篇
  1975年   54篇
  1974年   76篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use.  相似文献   
92.
93.
94.
The addition of candesartan cilexetil (Atacand®, Amias®, Biopress®, Kenzen®, Ratacand®) to standard therapy for chronic heart failure (CHF) provided important clinical benefits at little or no additional cost in France, Germany, and the UK, according to a detailed economic analysis focusing on major cardiovascular events and prospectively collected resource-use data from the CHARM-Added and CHARM-Alternative trials in patients with CHF and left ventricular (LV) systolic dysfunction. Results of a corresponding cost-effectiveness analysis showed that candesartan cilexetil was either dominant over placebo or was associated with small incremental costs per life-year gained, depending on the country and whether individual trial or pooled data were used. Preliminary data from a US cost-effectiveness analysis based on CHARM data also showed favorable results for candesartan cilexetil.Two cost-effectiveness analyses of candesartan cilexetil in hypertension have been published, both conducted in Sweden. Data from the SCOPE trial in elderly patients with hypertension, which showed a significant reduction in nonfatal stroke with candesartan cilexetil-based therapy versus non-candesartan cilexetil-based treatment, were incorporated into a Markov model and an incremental cost-effectiveness ratio of €12 824 per quality-adjusted life-year (QALY) gained was calculated (2001 value). Another modelled cost-effectiveness analysis of candesartan cilexetil was based on the ALPINE trial, in which the incidence of new-onset diabetes was significantly lower in patients with newly diagnosed hypertension who were randomized to candesartan cilexetil (with or without felodipine) than among those who received hydrochlorothiazide (with or without atenolol). Although candesartan cilexetil was dominant over hydrochlorothiazide, the ALPINE cost-effectiveness analysis relied on a small number of clinical events and did not evaluate the incremental cost of candesartan cilexetil per life-year or QALY gained.In conclusion, despite some inherent limitations, economic analyses incorporating CHARM data and conducted primarily in Europe have shown that candesartan cilexetil appears to be cost effective when added to standard CHF treatment in patients with CHF and compromized LV systolic function. The use of candesartan cilexetil as part of antihypertensive therapy in elderly patients with elevated blood pressure was also deemed to be cost effective in a Swedish analysis, primarily resulting from a reduced risk of nonfatal stroke (as shown in the SCOPE study); however, the generalizability of results to other contexts has not been established. Cost-effectiveness analyses comparing candesartan cilexetil with ACE inhibitors or other angiotensin receptor blockers in CHF or hypertension are lacking, and results reported for candesartan cilexetil in a Swedish economic analysis of ALPINE data focusing on outcomes for diabetes require confirmation and extension.  相似文献   
95.
Cholesterol intakes in Britain have been re-estimated by analysing Total Diet samples taken in 1991 and from 1993 National Food Survey records. The Total Diet samples contained only 284 mg/day compared with 319 mg/day in 1987 and 337 mg/day in 1981, while the National Food Survey showed intakes had fallen to 238 mg/day from 259 mg/day in 1990 and 405 mg/day in 1970-75. More details of the intakes by adults in 1986/87 are given, and compared with the results from the other methods. Daily intakes of eight phytosterols were also estimated, the main ones being β-sitosterol, campesterol, stigmasterol and 57-stigmastenol whose intakes were 104, 49, 10 and 4 mg/day, respectively, in 1991. These intakes had increased since 1981, reflecting the rising consumption of vegetable oils.  相似文献   
96.
97.
98.
This paper concerns the analysis of menstrual data; in particular, methodology to identify variables that contribute to the variability of menstrual cycles both within and between women. The basis for the proposed methodology is a parameterization of the mean length of a menstrual cycle conditional upon the past cycles and covariates. This approach accommodates the length-bias and censoring commonly found in menstrual data. Data from a longitudinal study of menstrual patterns and other variables among Lese women of the Ituri Forest, Zaire, illustrate the methodology. A small simulation illustrates the bias caused by incorrectly deleting the censored cycles.  相似文献   
99.
Several states have designed and implemented innovative programs for Medicaid beneficiaries that carve-out the provision of mental health from general health care. This paper describes several such programs and outlines the choices states face in designing these services. Major decisions include the selection of a public or private agency, how that agency is chosen, reimbursement schemes, eligibility criteria, and benefits to be covered. While carve-out programs have yielded initial savings, more research is needed on their effect on quality of care and general health care costs.  相似文献   
100.
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