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   8563篇
  免费   861篇
  国内免费   52篇
耳鼻咽喉   93篇
儿科学   368篇
妇产科学   150篇
基础医学   1160篇
口腔科学   289篇
临床医学   912篇
内科学   1899篇
皮肤病学   186篇
神经病学   727篇
特种医学   354篇
外国民族医学   2篇
外科学   1223篇
综合类   107篇
一般理论   1篇
预防医学   737篇
眼科学   171篇
药学   432篇
中国医学   15篇
肿瘤学   650篇
  2023年   53篇
  2022年   76篇
  2021年   207篇
  2020年   100篇
  2019年   252篇
  2018年   313篇
  2017年   238篇
  2016年   222篇
  2015年   269篇
  2014年   319篇
  2013年   444篇
  2012年   446篇
  2011年   417篇
  2010年   330篇
  2009年   298篇
  2008年   348篇
  2007年   401篇
  2006年   391篇
  2005年   331篇
  2004年   276篇
  2003年   257篇
  2002年   279篇
  2001年   188篇
  2000年   208篇
  1999年   198篇
  1998年   167篇
  1997年   156篇
  1996年   153篇
  1995年   117篇
  1994年   123篇
  1993年   79篇
  1992年   156篇
  1991年   177篇
  1990年   141篇
  1989年   162篇
  1988年   148篇
  1987年   126篇
  1986年   137篇
  1985年   98篇
  1984年   79篇
  1983年   63篇
  1982年   43篇
  1981年   42篇
  1980年   41篇
  1979年   55篇
  1978年   28篇
  1977年   37篇
  1976年   42篇
  1975年   29篇
  1973年   35篇
排序方式: 共有9476条查询结果,搜索用时 15 毫秒
991.

Introduction  

Vascular inflammation is common in certain systemic autoimmune diseases and contributes to the oxidation of low-density lipoprotein (oxLDL) and oxLDL/β2-glycoprotein I (β2GPI) complex formation. These complexes have been implicated as proatherogenic autoantigens that participate in the development of atherosclerotic disease.  相似文献   
992.
Human follicular fluid (hFF), as an extra oocyte microenvironment, is essential to the biological processes of oocyte development. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified 426 proteins as consistently present in hFF from different participants. According to our gene chip data, the granulosa cells in the follicle locally produce 235 of these proteins. These data suggest that the granulosa cells actively participate in the follicular development by synthesizing important molecules to support the activity of pathways that are essential to oocyte development and genomic preservation. The computational Ingenuity Pathway Analysis (IPA) suggests that the identified proteins have well-established functions in the pathways of steroidogenesis, cell-to-cell signaling and interaction, molecular transport, the antioxidative system, interleukin 1 (IL-1) and IL-6 signaling, liver X receptor/retinoid X receptor (LXR/RXR) activation, and the interconnective insulin-like growth factor and lipid metabolism networks. The hFF peptide composition is likely to serve not only the inflammatory follicular state as has been previously suggested; rather, it is a highly diverse and multifunctional environment with several interconnected pathways. These results provide us with important knowledge related to the environment in which the oocyte develops as well as the molecular basis for controlling the process independently of blood supply.  相似文献   
993.
994.
In 2008, an increase in the prevalence of carbapenem-resistant Klebsiella pneumoniae was noted in a 286-bed tertiary case hospital in Colombia, where 84 patients (32 infected and 52 colonized) had positive cultures. The identified index patient came from Israel for a liver transplantation. High level carbapenem resistance was observed. Polymyxin B and tigecycline were the only two antibiotics that remained active. PCR-restriction fragment length polymorphism analysis and sequencing revealed blaKPC-3 in the major clone, which was indistinguishable from the K. pneumoniae carbapenemase-3-producing clone described previously in Israel. This exemplifies the threat posed by the global spread of K. pneumoniae carbapenemase-producing pathogens.  相似文献   
995.
Porcine epidemic diarrhoea virus (PEDV) infects pigs of all ages causing vomiting and diarrhoea. PEDV is transmitted via the oral–faecal route, and a very low dose is enough to infect susceptible pigs, resulting in significant production losses. This short communication aims to describe the introduction of PEDV into a 10,000-sow farrow-to-wean farm located in northwest Mexico. Following the onset of clinical signs, an outbreak investigation was conducted to determine the most probable route of introduction. Based on data collected from interviews, construction of a timeline of events, and the detection of PEDV RNA in feed samples and samples collected from various surfaces of feed transport vehicles, it was concluded that the most probable route for PEDV incursion into this breeding herd was contaminated feed or a contaminated feed transport vehicle. This paper describes how feed or feed transport could serve as potential routes of PEDV infection to a farm and highlights the importance of establishing biosecurity programs to mitigate these risks.  相似文献   
996.
Niedmers  H.  Defosse  J. M.  Wappler  F.  Lopez  A.  Schieren  M. 《Der Anaesthesist》2022,71(8):608-617
Die Anaesthesiologie - Während zahlreiche Kliniken in Deutschland thoraxchirurgische Eingriffe durchführen, liegen bisher nur unzureichende Daten über die verwendeten...  相似文献   
997.
998.
999.
The risk of fragility fracture increases for people with type 2 diabetes mellitus (T2DM), even after controlling for bone mineral density, body mass index, visual impairment, and falls. We hypothesize that progressive glycemic derangement alters microscale bone tissue composition. We used Fourier-transform infrared (FTIR) imaging to analyze the composition of iliac crest biopsies from cohorts of postmenopausal women characterized by oral glucose tolerance testing: normal glucose tolerance (NGT; n = 35, age = 65 ± 7 years, HbA1c = 5.8 ± 0.3%), impaired glucose tolerance (IGT; n = 26, age = 64 ± 5 years, HbA1c = 6.0 ± 0.4%), and overt T2DM on insulin (n = 25, age = 64 ± 6 years, HbA1c = 9.13 ± 0.6). The distributions of cortical bone mineral content had greater mean values (+7%) and were narrower (−10%) in T2DM versus NGT groups (p < 0.05). The distributions of acid phosphate, an indicator of new mineral, were narrower in cortical T2DM versus NGT and IGT groups (−14% and −14%, respectively) and in trabecular NGT and IGT versus T2DM groups (−11% and −10%, respectively) (all p < 0.05). The distributions of crystallinity were wider in cortical NGT versus T2DM groups (+16%) and in trabecular NGT versus T2DM groups (+14%) (all p < 0.05). Additionally, bone turnover was lower in T2DM versus NGT groups (P1NP: −25%, CTx: −30%, ucOC: −24%). Serum pentosidine was similar across groups. The FTIR compositional and biochemical marker values of the IGT group typically fell between the NGT and T2DM group values, although the differences were not always statistically significant. In summary, worsening glycemic control was associated with greater mineral content and narrower distributions of acid phosphate, an indicator of new mineral, which together are consistent with observations of lower turnover; however, wider distributions of mineral crystallinity were also observed. A more mineralized, less heterogeneous tissue may affect tissue-level mechanical properties and in turn degrade macroscale skeletal integrity. In conclusion, these data are the first evidence of progressive alteration of bone tissue composition with worsening glycemic control in humans. © 2020 American Society for Bone and Mineral Research (ASBMR).  相似文献   
1000.
The acute phase of influenza infection is rarely associated with significant cognitive dysfunction. We describe a case of a 24 year-old man who developed global amnesia in the acute phase of influenza A infection. His deficits resolved over the course of several weeks. Transient abnormalities of diffusion and T2-weighted imaging were seen in the bilateral hippocampi. We review cerebral complications of influenza and discuss the possible role of previously proposed mechanisms in our patient’s case.  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