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   194127篇
  免费   13489篇
  国内免费   5428篇
耳鼻咽喉   2657篇
儿科学   2761篇
妇产科学   2516篇
基础医学   28026篇
口腔科学   4341篇
临床医学   19687篇
内科学   31702篇
皮肤病学   5036篇
神经病学   13450篇
特种医学   10005篇
外国民族医学   21篇
外科学   23211篇
综合类   12576篇
现状与发展   31篇
一般理论   31篇
预防医学   11872篇
眼科学   5326篇
药学   18982篇
  67篇
中国医学   5187篇
肿瘤学   15559篇
  2024年   257篇
  2023年   1805篇
  2022年   4878篇
  2021年   7317篇
  2020年   4331篇
  2019年   4871篇
  2018年   5735篇
  2017年   4994篇
  2016年   5824篇
  2015年   8371篇
  2014年   10124篇
  2013年   11117篇
  2012年   16490篇
  2011年   16429篇
  2010年   10028篇
  2009年   8752篇
  2008年   11771篇
  2007年   11169篇
  2006年   10321篇
  2005年   9435篇
  2004年   7845篇
  2003年   7271篇
  2002年   6159篇
  2001年   4681篇
  2000年   4172篇
  1999年   3354篇
  1998年   1675篇
  1997年   1349篇
  1996年   1106篇
  1995年   989篇
  1994年   906篇
  1993年   673篇
  1992年   1128篇
  1991年   1045篇
  1990年   930篇
  1989年   825篇
  1988年   644篇
  1987年   655篇
  1986年   479篇
  1985年   473篇
  1984年   320篇
  1983年   231篇
  1982年   169篇
  1981年   197篇
  1980年   156篇
  1979年   242篇
  1978年   171篇
  1976年   136篇
  1974年   143篇
  1973年   130篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
A role for type II interferon (IFN-gamma) in resolving viral infection is suggested by the correlation of hepatitis C virus (HCV) clearance with enhancement of IFN-gamma-producing activated T cells in the resolution of acute HCV infection. Using vesicular stomatitis virus (VSV), a synergistic direct antiviral effect was documented using IFN-gamma1b and a potent, consensus type I IFN (IFN alfacon-1). Global expression profiling following EC50 exposure to IFN alfacon-1, IFN-gamma1b, or a cocktail of the two allowed the antiviral state to be correlated with induction of a subset of IFN-stimulated genes (ISGs). Genes identified through this analysis corresponded to classic antiviral components, ISGs more recently associated with direct antiviral functions, as well as expressed sequence tags (ESTs) and hypothetical proteins. The magnitude of these antiviral EC50-correlated expression events in human hepatoma (Huh7) cells exposed to clinically relevant doses of IFN alfacon-1, IFN-gamma1b, or a cocktail of the two was also probed because the standard of care for patients with chronic hepatitis C is type I IFN-containing regimens. Relative to type I IFNs used alone, the addition of type II IFN caused enhanced expression not only of many of the genes correlated with the direct antiviral state but also of genes involved in (1) antigen presentation to cytotoxic T lymphocytes (CTLs), (2) macrophage, natural killer (NK), and T helper 1 (Th1) cell recruitment and activation, (3) complement system function, (4) apoptosis, and (5) ISGs with unknown functions. As many of these processes are correlated clinically with resolution of chronic HCV infection, the combined use of these IFNs could display a beneficial effect on viral clearance in patients infected with HCV and other viruses through enhancement of one of these processes or of the direct antiviral state.  相似文献   
72.
73.
74.
75.
Diseases like rotavirus afflict both upper- and lower-income countries, but most serious illnesses and deaths occur among the latter. It is a vital public health issue that vaccines for these types of global diseases can recover research and development (R&D) costs from high-priced markets quickly so that manufacturers can offer affordable prices to lower-income nations. Cost recovery depends on how high R&D costs are, and this study attempts to replace high, unverified estimates with lower, more verifiable estimates for two new vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline or GSK), based on detailed searches of public information and follow-up interviews with senior informants. We also offer a new perspective on “cost of capital” as a claim for recovery from public bodies. Our estimates suggest that companies can recover all fixed costs quickly from affluent markets and thus can offer these vaccines to lower-income countries at prices they can afford. Better vaccines are a shared project between companies and public health agencies; greater transparency and consistency in reporting of R&D costs is needed so that fair prices can be established.  相似文献   
76.
目的 评价诊断中老年男子部分雄激素缺乏综合征(PADAM)的游离睾酮指数(FTI).方法 对129例45岁以上健康男性的FTI进行年龄相关分析.以推算的游离睾酮(CFT)值为依据,对FTI进行有效性检验.结果 男子在中老年期FTI与增龄呈明显的负相关.FTI敏感性97.78%,特异性58.33%.结论 计算简单的FTI可用于PADAM病人的筛选和随访,尤其对70岁以上男子是血清FT较为有效的参数.  相似文献   
77.
78.
BACKGROUND: Dialysis patient mortality remains high, and this high mortality may be due to many factors. In peritoneal dialysis (PD) patients, old age, co-morbid diseases, malnutrition, low residual renal function (RRF) and a high peritoneal transport rate have been shown to influence survival, but the relative importance of these factors may differ between different patient populations. Besides, centre practice patterns may differ between centres and may influence patient survival. In addition, the literature suggests that dialysis patient survival may be better in Asian than in Caucasian patients. METHODS: The influence of centre and patient characteristics on patient survival was investigated in 132 Korean and 106 Swedish incident PD patients, who underwent initial biochemical measurements and assessment of adequacy of dialysis, nutritional status, RRF and peritoneal transport characteristics. RESULTS: At the start of PD, Korean patients had a higher prevalence of diabetes, peritoneal Kt/V(urea), peritoneal creatinine clearance and peritoneal fluid removal, and lower body mass index, RRF and dialysate to plasma creatinine concentration ratio (D/P Cr) compared with Swedish patients. Significantly more patients from Korea were placed on temporary haemodialysis before PD (100 out of 132) when compared with Swedish patients (21 out of 106). During the follow-up, there was a significantly higher rate of transfer to other units in Korea and a significantly higher rate of kidney transplantation in Sweden. On Kaplan-Meier analysis, overall patient survival did not differ and relative risk for death was also not different between the two centres even after adjustment for age, diabetes, cardiovascular disease, RRF and D/P Cr. On Cox proportional hazards multivariate analysis, age, diabetes, RRF and D/P Cr were found to be independent predictors of mortality in the combined cohort of patients. While age, diabetes and D/P Cr were independent predictors of mortality in Korean patients, age and RRF independently predicted mortality in Swedish patients. CONCLUSION: Although there were significant differences in centre and patient characteristics, we were unable to confirm a survival advantage for Korean over Swedish PD patients. The results of this study suggest that the reported difference in survival between Asian and Caucasian dialysis patients may have been due, in part, to differences in centre and patient characteristics rather than to race as such. The genetic influence on patient characteristics remains, however, to be elucidated.  相似文献   
79.
[目的]探讨外固定支架结合骨折端局部注射自体骨髓多能干细胞治疗桡骨远端粉碎性骨折的有效性。[方法]应用外固定支架结合骨折端局部注射自体骨髓多能干细胞治疗桡骨远端粉碎性骨折18例。[结果]随访6~15个月(平均8个月),优10例,良6例,可2例,差0例。优良率为88.9%。没有一例出现针道浅表感染等并发症。[结论]外固定支架结合骨折端局部注射自体骨髓多能干细胞是治疗桡骨远端粉碎性骨折的一种方便、有效的方法,不仅骨折愈合效果满意,而且固定确实可靠,并能早期功能调整和训练。  相似文献   
80.
我们自2000年10月至2008年12月采用大承气汤加黄连应用与肛周常见疾病术后病人,治疗其术后大小便潴留,里急后重等症状,取得了满意的疗效,现报告如下.  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