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   3373篇
  免费   170篇
  国内免费   16篇
耳鼻咽喉   80篇
儿科学   138篇
妇产科学   35篇
基础医学   296篇
口腔科学   115篇
临床医学   310篇
内科学   726篇
皮肤病学   82篇
神经病学   244篇
特种医学   97篇
外科学   609篇
综合类   40篇
一般理论   2篇
预防医学   116篇
眼科学   137篇
药学   297篇
中国医学   12篇
肿瘤学   223篇
  2024年   4篇
  2023年   49篇
  2022年   126篇
  2021年   222篇
  2020年   129篇
  2019年   132篇
  2018年   163篇
  2017年   108篇
  2016年   124篇
  2015年   157篇
  2014年   204篇
  2013年   195篇
  2012年   331篇
  2011年   311篇
  2010年   176篇
  2009年   151篇
  2008年   175篇
  2007年   200篇
  2006年   158篇
  2005年   125篇
  2004年   95篇
  2003年   92篇
  2002年   58篇
  2001年   8篇
  2000年   9篇
  1999年   10篇
  1998年   12篇
  1997年   4篇
  1996年   4篇
  1995年   6篇
  1994年   4篇
  1993年   2篇
  1992年   1篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1986年   2篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1977年   1篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有3559条查询结果,搜索用时 0 毫秒
61.
62.
63.
BackgroundData on convalescent plasma therapy (CPT) in patients of hematological malignancies with severe Covid-19 is scarce.ObjectiveTo study 14-day mortality in patients who received CPT.Patients & methodsRetrospective multicentre observational study conducted in 4 centres treating haematological malignancies across Delhi-national capital region. Total 33 haematological malignancies patients with severe Covid-19 who received CPT were analysed.ResultsThe median age of the study cohort was 62 years (18–80 years). Twenty one percent patients had 1 comorbidity, 18 % had 2 comorbidities and 6% patients had 3 and 5 comorbidities each. Twenty four patients were on active therapy. Sixty nine percent of patients required ICU stay. Twenty five patients received plasma therapy within 7 days (early) of diagnosis of Covid-19 infection. Median day of plasma infusion from date of diagnosis of Covid-19 infection was 4 days (range: 2–25 days). Patient who had early initiation of plasma therapy had shorter duration of hospitalisation (12.7 vs 24.3 days, p = 0.000). Overall mortality in the cohort was 45.5%. There was no effect of disease status, active therapy, presence of comorbidity on mortality. There was no difference in the mortality in patients receiving early vs late initiation of plasma therapy or in patients receiving one versus two plasma therapy.ConclusionsWe provide a large series of patients with hematological malignancies and role of CPT in this group.  相似文献   
64.
The International Journal of Cardiovascular Imaging - Abnormal atrial mechanics in biventricular circulations have been associated with elevated left heart filling pressures. Similar associations...  相似文献   
65.

Purpose

Conjoined twins are a rare complication of 9 monozygotic twins and are associated with high perinatal mortality. Pygopagus are one of the rare types of conjoined twins with only a handful of cases reported in the literature.

Case summary

We present the case of one-and-half month-old male pygopagus conjoined twins, who were joined together dorsally in lower lumbar and sacral region and had spina bifida and shared a single thecal sac with combined weight of 6.14 kg. Spinal cord was separated at the level of the conus followed by duraplasty. They had uneventful recovery with normal 15 months follow-up.

Conclusion

Separation of conjoined twins is recommended in where this is feasible with the anticipated survival of both or one infant.
  相似文献   
66.
European Spine Journal - The aim of the study was to investigate if axial T1ρ MR images had similar accuracy as established sagittal T1ρ MRI for the assessment of proteoglycan...  相似文献   
67.
Metabolic syndrome is a cluster of risk factors for cardiovascular disease that include obesity, atherogenic dyslipidemia, raised blood pressure, and insulin resistance. The growing trend of obesity is associated with increased prevalence of metabolic syndrome. Optimizing diet and exercise are still the leading therapy for controlling the metabolic syndrome. Based on the current evidence, further emphasis should be placed on aggressive management of other metabolic risk factors such as high blood pressure and dyslipidemia.  相似文献   
68.
Anabolic biosynthesis requires precursors supplied by the Krebs cycle, which in turn requires anaplerosis to replenish precursor intermediates. The major anaplerotic sources are pyruvate and glutamine, which require the activity of pyruvate carboxylase (PC) and glutaminase 1 (GLS1), respectively. Due to their rapid proliferation, cancer cells have increased anabolic and energy demands; however, different cancer cell types exhibit differential requirements for PC- and GLS-mediated pathways for anaplerosis and cell proliferation. Here, we infused patients with early-stage non–small-cell lung cancer (NSCLC) with uniformly 13C-labeled glucose before tissue resection and determined that the cancerous tissues in these patients had enhanced PC activity. Freshly resected paired lung tissue slices cultured in 13C6-glucose or 13C5,15N2-glutamine tracers confirmed selective activation of PC over GLS in NSCLC. Compared with noncancerous tissues, PC expression was greatly enhanced in cancerous tissues, whereas GLS1 expression showed no trend. Moreover, immunohistochemical analysis of paired lung tissues showed PC overexpression in cancer cells rather than in stromal cells of tumor tissues. PC knockdown induced multinucleation, decreased cell proliferation and colony formation in human NSCLC cells, and reduced tumor growth in a mouse xenograft model. Growth inhibition was accompanied by perturbed Krebs cycle activity, inhibition of lipid and nucleotide biosynthesis, and altered glutathione homeostasis. These findings indicate that PC-mediated anaplerosis in early-stage NSCLC is required for tumor survival and proliferation.  相似文献   
69.
TNF ligand superfamily member 12, also known as TNF-related weak inducer of apoptosis (TWEAK), acts through its receptor, fibroblast growth factor-inducible 14 (Fn14), to mediate several key pathologic processes involved in tissue injury relating to lupus nephritis. To explore the potential for renal protection in lupus nephritis by targeting this pathway, we introduced the Fn14 null allele into the MRL-lpr/lpr lupus mouse strain. At 26–38 weeks of age, female Fn14-knockout MRL-lpr/lpr mice had significantly lower levels of proteinuria compared with female wild-type MRL-lpr/lpr mice. Furthermore, Fn14-knockout mice had significantly improved renal histopathology accompanied by attenuated glomerular and tubulointerstitial inflammation. There was a significant reduction in glomerular Ig deposition in Fn14-knockout mice, despite no detectable differences in either serum levels of antibodies or splenic immune cell subsets. Notably, we found that the Fn14-knockout mice displayed substantial preservation of podocytes in glomeruli and that TWEAK signaling directly damaged barrier function and increased filtration through podocyte and glomerular endothelial cell monolayers. Our results show that deficiency of the Fn14 receptor significantly improves renal disease in a spontaneous lupus nephritis model through prevention of the direct injurious effects of TWEAK on the filtration barrier and/or modulation of cytokine production by resident kidney cells. Thus, blocking the TWEAK/Fn14 axis may be a novel therapeutic intervention in immune-mediated proliferative GN.  相似文献   
70.
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