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   28502篇
  免费   1359篇
  国内免费   166篇
耳鼻咽喉   406篇
儿科学   448篇
妇产科学   502篇
基础医学   3719篇
口腔科学   706篇
临床医学   2066篇
内科学   7878篇
皮肤病学   371篇
神经病学   2167篇
特种医学   914篇
外科学   4826篇
综合类   114篇
一般理论   1篇
预防医学   817篇
眼科学   428篇
药学   1829篇
中国医学   57篇
肿瘤学   2778篇
  2022年   210篇
  2021年   476篇
  2020年   269篇
  2019年   326篇
  2018年   461篇
  2017年   360篇
  2016年   433篇
  2015年   489篇
  2014年   671篇
  2013年   856篇
  2012年   1261篇
  2011年   1349篇
  2010年   749篇
  2009年   685篇
  2008年   1291篇
  2007年   1418篇
  2006年   1401篇
  2005年   1290篇
  2004年   1334篇
  2003年   1297篇
  2002年   1388篇
  2001年   955篇
  2000年   976篇
  1999年   885篇
  1998年   374篇
  1997年   297篇
  1996年   274篇
  1995年   256篇
  1994年   232篇
  1993年   205篇
  1992年   654篇
  1991年   674篇
  1990年   571篇
  1989年   571篇
  1988年   543篇
  1987年   528篇
  1986年   446篇
  1985年   447篇
  1984年   338篇
  1983年   259篇
  1982年   126篇
  1979年   244篇
  1978年   152篇
  1977年   153篇
  1974年   136篇
  1973年   131篇
  1972年   143篇
  1971年   135篇
  1969年   140篇
  1967年   130篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.

Background

There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).

Methods

Patients with AEG and UGC who were judged as non-sarcopenic before surgery were reassessed the presence of postoperative development of sarcopenia 6 months after surgery. Patients were divided into the development group or non-development group, and clinicopathological factors and prognosis between these two groups were analyzed.

Results

The 5-year overall survival rates were significantly poorer in the development group than non-development group (68.0% vs. 92.6%, P?=?0.0118). Multivariate analyses showed that postoperative development of sarcopenia was an independent prognostic factor for poor overall survival (P?=?0.0237).

Conclusions

Postoperative development of sarcopenia was associated with a poor prognosis in patients with AEG and UGC.  相似文献   
3.
4.
5.
Syphilis is a sexually transmitted disease caused by Treponema pallidum. Syphilitic aortitis might coexist in a dysfunctional aortic valve, but the etiology remains unclear, because microbiological diagnosis is difficult. A 62-year-old man with low-grade fever was diagnosed with aortitis and infective endocarditis, due to Treponema pallidum infection, using polymerase chain reaction analysis. This case suggests that syphilis might cause infective endocarditis.  相似文献   
6.
7.
Abstract: The risk of cardiovascular death is high in hemodialysis (HD) patients, and thickening, stiffening and calcification of the arterial wall have been shown as its predictive factors. Activated vitamin D preparations are used for the treatment of secondary hyperparathyroidism in HD patients, but as they increase serum phosphate and calcium concentrations, there is a concern that they promote vascular calcification and, consequently, exacerbate the outcomes. In this article, the effects of vitamin D therapy on survival, cardiac function, arteriosclerosis, immunity, and inflammation are evaluated by reviewing the literature. In HD patients, the risk of death (particularly cardiovascular death) is significantly lower in those treated than in those not treated with vitamin D. Moreover, activated vitamin D improves cardiac function and alleviates cardiac hypertrophy in HD patients. Experimental data in cultured macrophages, vascular smooth muscle cells, and vascular endothelial cells suggest that it has antiatherosclerotic effects. In vivo, the administration of vitamin D improves immune functions and normalizes inflammatory reactions. In HD patients, vascular calcification is related to the dose of calcium carbonate, but its relationship with the administration of vitamin D is not significant. These observations suggest that, contrary to the general concerns, activated vitamin D exerts favorable effects on the cardiovascular system in HD patients as long as it is used in appropriate clinical doses.  相似文献   
8.
There have been no systematic efforts to manage and treat patients with frontotemporal dementia (FTD), but Perry described pharmacologic interventions for some behavioral syndromes in 2001. In Perry's report, selective serotonin reuptake inhibitors (SSRI) were recommended as first choice drugs because they were well tolerated and might have an effect on some symptoms such as compulsive symptoms and eating abnormalities. Some reports were presented concerning Japanese FTD patients which showed the effect of SSRI on stereotyped behaviors and eating abnormalities by Nishikawa, et al. (2001), Ikeda, et al. (2004), and others. We describe two FTD patients with compulsive complaints of pain, one mainly on abdomen and the other on lumbar region. Fluvoxamine markedly improved their complaints of pain as well as stereotyped symptoms. Fluvoxamine might be effective for behavioral disturbances due to improvement of serotoninergic dysfunction in frontal medial and cingulated cortices, as previously described. Moreover, it has been reported that an altered response to pain stimuli, either via a loss of awareness of pain or exaggerated reaction to pain, is a specific feature of FTD, but there have been only a few reports on this feature. Fluvoxamine might be effective for compulsive complaints of pain due to improvements of compulsive symptoms and exaggerated reactions to pain in FTD, or due to the analgesic effect of SSRI. SSRI may improve compulsive complaints of pain in FTD patients.  相似文献   
9.
10.
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN.  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