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   1002644篇
  免费   77243篇
  国内免费   2614篇
耳鼻咽喉   13006篇
儿科学   34657篇
妇产科学   28664篇
基础医学   146051篇
口腔科学   28080篇
临床医学   90989篇
内科学   194678篇
皮肤病学   22979篇
神经病学   79759篇
特种医学   38671篇
外国民族医学   305篇
外科学   150514篇
综合类   24039篇
一般理论   396篇
预防医学   78548篇
眼科学   22743篇
药学   72217篇
  3篇
中国医学   2032篇
肿瘤学   54170篇
  2018年   10661篇
  2017年   8326篇
  2016年   9461篇
  2015年   10708篇
  2014年   14567篇
  2013年   22257篇
  2012年   29342篇
  2011年   31208篇
  2010年   18689篇
  2009年   17611篇
  2008年   29100篇
  2007年   30821篇
  2006年   31310篇
  2005年   29969篇
  2004年   29249篇
  2003年   28088篇
  2002年   27116篇
  2001年   47143篇
  2000年   48259篇
  1999年   40477篇
  1998年   11253篇
  1997年   10165篇
  1996年   10213篇
  1995年   9831篇
  1994年   9150篇
  1993年   8534篇
  1992年   32417篇
  1991年   31638篇
  1990年   31196篇
  1989年   30024篇
  1988年   27320篇
  1987年   27480篇
  1986年   25586篇
  1985年   24744篇
  1984年   18468篇
  1983年   15592篇
  1982年   9343篇
  1981年   8425篇
  1979年   16930篇
  1978年   12282篇
  1977年   10357篇
  1976年   9794篇
  1975年   10218篇
  1974年   12363篇
  1973年   11884篇
  1972年   10930篇
  1971年   10166篇
  1970年   9416篇
  1969年   8760篇
  1968年   8138篇
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
171.
172.
Prolidase deficiency is a rare autosomal recessive disorder characterized by cutaneous ulcers, facial dysmorphism, recurrent infections, and intellectual disability. We report a unique case of a 6‐year‐old boy with prolidase deficiency and Crohn's disease who presented with lower extremity ulcers. Cutaneous ulcers due to prolidase deficiency are historically resistant to treatment, and we report success with the novel use of topical tacrolimus.  相似文献   
173.
Psoriasis is a chronic disease that requires long‐term treatment. Consequently, understanding the safety and tolerability of any potential treatment over time is critical to effective prescribing. The biologic agents currently available for the treatment of psoriasis target a number of different inflammatory cytokines involved in psoriasis disease pathogenesis. The monoclonal antibodies tildrakizumab, guselkumab and risankizumab target the p19 subunit that is specific to interleukin (IL)‐23. This article reviews published data on the safety of these IL‐23p19 inhibitors in patients with psoriasis compared with other currently available biologic therapies. Data from randomized, placebo‐ and active‐controlled phase 3 clinical trials show tildrakizumab, guselkumab and risankizumab to have a favourable risk–benefit profile in patients with moderate to severe psoriasis. No significant safety concerns have been observed for any of these IL‐23p19 inhibitors in the data published to date. The most commonly reported adverse events (AEs) associated with these agents in phase 3 studies were upper respiratory tract infections. No increase was seen in rates of serious infections, malignancies or major adverse cardiovascular events, with no signals suggestive of an elevated risk of opportunistic infections, active tuberculosis or reactivation of latent tuberculosis infection, mucocutaneous Candida infections, triggering or worsening of inflammatory bowel disease, demyelinating disorders or suicidal ideation. Selectively targeting IL‐23p19 may help avoid AEs that have been associated with biologic agents with other mechanisms of action. Data from long‐term extension studies and patient registries will further establish the safety profile of IL‐23p19 inhibitors for the treatment of moderate to severe psoriasis in routine practice.  相似文献   
174.
175.
Digestive Diseases and Sciences - To determine whether the presence of portal vein thrombosis (PVT) where venous flow within the liver may be altered may delay the diagnosis of HCC and be...  相似文献   
176.
ABSTRACT

Although exclusive breastfeeding has been linked to lower rates of postnatal HIV transmission compared to nonexclusive breastfeeding, mechanisms underlying this are unclear. Across a longitudinally sampled cohort of South African infants, we showed that exclusively breastfed (EBF) infants had altered gut bacterial communities when compared to nonexclusively breastfed (NEBF) infants, as well as reduced peripheral CD4 + T cell activation and lowered chemokine and chemokine receptor expression in the oral mucosa. We further demonstrated that the relative abundance of key taxa was correlated with peripheral CD4 + T cell activation. Here, we supplement those findings by using compositional data analyses to identify shifts in the abundance of several Bifidobacteria strains relative to select strains of Escherichia, Bacteroides, and others that are associated with the transition to NEBF. We illustrate that the abundance ratio of these taxa is tightly correlated with feeding modality and is a strong predictor of peripheral T cell activation. More broadly, we discuss our study in the context of novel developments and explore future directions for the field.  相似文献   
177.
178.
179.
180.
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