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   1357346篇
  免费   85056篇
  国内免费   1911篇
耳鼻咽喉   18940篇
儿科学   44665篇
妇产科学   38514篇
基础医学   205600篇
口腔科学   36255篇
临床医学   117246篇
内科学   259780篇
皮肤病学   28762篇
神经病学   101208篇
特种医学   52153篇
外国民族医学   348篇
外科学   206660篇
综合类   26276篇
现状与发展   1篇
一般理论   302篇
预防医学   98829篇
眼科学   31186篇
药学   102907篇
  23篇
中国医学   2677篇
肿瘤学   71981篇
  2018年   13135篇
  2016年   11191篇
  2015年   12679篇
  2014年   17415篇
  2013年   26166篇
  2012年   36727篇
  2011年   39615篇
  2010年   23268篇
  2009年   21557篇
  2008年   37829篇
  2007年   41128篇
  2006年   41364篇
  2005年   40317篇
  2004年   38934篇
  2003年   37849篇
  2002年   37249篇
  2001年   59607篇
  2000年   61065篇
  1999年   51694篇
  1998年   14587篇
  1997年   13006篇
  1996年   13144篇
  1995年   12389篇
  1994年   11663篇
  1993年   10802篇
  1992年   41387篇
  1991年   41664篇
  1990年   41227篇
  1989年   40216篇
  1988年   37371篇
  1987年   36671篇
  1986年   34871篇
  1985年   33169篇
  1984年   24679篇
  1983年   21498篇
  1982年   12505篇
  1981年   11009篇
  1979年   23710篇
  1978年   16589篇
  1977年   14230篇
  1976年   13820篇
  1975年   15437篇
  1974年   18051篇
  1973年   17425篇
  1972年   16435篇
  1971年   15358篇
  1970年   14381篇
  1969年   13798篇
  1968年   13028篇
  1967年   11479篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
86.
87.

Objective

To assess the incidence of pertussis (whooping cough) in subjects aged 50 years and older in France.

Methods

Participating family physicians (FPs) using the patient record management software AxiSanté® included patients aged 50 years and older, who had signed an informed consent form, presenting with persistent cough for 7 to 21 days. Bordetella genetic material was detected by polymerase chain reaction (PCR) on nasopharyngeal samples collected at the FP's discretion.

Results

A total of 42 FPs included 129 patients from June 2013 to August 2014 (large cities: 38; medium-sized cities: 57; rural areas: 34); 106 samples were analyzed. Overall, 30 pertussis cases were diagnosed: 10 cases confirmed by PCR, 18 purely clinical cases, and two direct epidemiological cases. The crude incidence rate per 100,000 patients aged  50 years was 103.6 (95% CI: 69.9–47.9): 77.1 in large cities, 103.1 in medium-sized cities, and 143.9 in rural areas. The extrapolated incidence rate per 100,000 persons aged  50 years was 187.1 (95% CI: 126.2–67.1): 131.1 in large cities, 256.1 in medium-sized cities, and 242.2 in rural areas.

Conclusion

The population aged 50 years and older can serve as a reservoir. Its role in Bordetella pertussis circulation should be taken into account for pertussis booster vaccination programs.  相似文献   
88.
89.
Iron-oxide nanoparticles (NPs) generated by environmental events are likely to represent health problems. α-Fe2O3 NPs were synthesized, characterized and tested in a model for toxicity utilizing human whole blood without added anticoagulant. MALDI-TOF of the corona was performed and activation markers for plasma cascade systems (complement, contact and coagulation systems), platelet consumption and release of growth factors, MPO, and chemokine/cytokines from blood cells were analyzed. The coronas formed on the pristine α-Fe2O3 NPs contained contact system proteins and they induced massive activation of the contact (kinin/kallikrein) system, as well as thrombin generation, platelet activation, and release of two pro-angiogeneic growth factors: platelet-derived growth factor and vascular endothelial growth factor, whereas complement activation was unaffected. The α-Fe2O3 NPs exhibited a noticeable toxicity, with kinin/kallikrein activation, which may be associated with hypotension and long-term angiogenesis in vivo, with implications for cancer, arteriosclerosis and pulmonary disease.  相似文献   
90.
ApoB-100 and Phosphatidylcholine-specific phospholipase C (PC-PLC) are important contributors to atherosclerosis development. ApoB-100 is the main structural protein of LDL, being directly associated with atherosclerosis plaque generation. PC-PLC is highly expressed in atherosclerosis lesions and contributes to their progression. We show how phosphatidylcholine-coated nanomicelles can be used for specific characterisation of atherosclerosis plaque. Results show that ApoB-100 in the protein corona of the nanomicelle targets the particles to atherosclerotic areas in apolipoprotein E?/? mice. Furthermore, PC-PLC selectively removes the polar heads from the phospholipid coating of the nanomicelles leading to their accumulation. To fully characterise the behaviour of the nanomicelles, we developed multimodal probes using a nanoemulsion step. Hybrid imaging revealed plaque accumulation of the nanomicelles and colocalisation with PC-PLC expression and ApoB-100 in the plaque. This study shows how protein corona composition and enzyme-driven nanomaterial accumulation can be used for detection of atherosclerosis.  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