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   11202篇
  免费   521篇
  国内免费   53篇
耳鼻咽喉   131篇
儿科学   150篇
妇产科学   141篇
基础医学   1276篇
口腔科学   260篇
临床医学   711篇
内科学   2954篇
皮肤病学   183篇
神经病学   835篇
特种医学   429篇
外科学   2176篇
综合类   58篇
一般理论   1篇
预防医学   246篇
眼科学   148篇
药学   936篇
中国医学   23篇
肿瘤学   1118篇
  2023年   61篇
  2022年   146篇
  2021年   258篇
  2020年   123篇
  2019年   188篇
  2018年   232篇
  2017年   219篇
  2016年   246篇
  2015年   242篇
  2014年   324篇
  2013年   395篇
  2012年   569篇
  2011年   697篇
  2010年   381篇
  2009年   356篇
  2008年   547篇
  2007年   691篇
  2006年   627篇
  2005年   618篇
  2004年   647篇
  2003年   633篇
  2002年   623篇
  2001年   212篇
  2000年   228篇
  1999年   228篇
  1998年   132篇
  1997年   104篇
  1996年   101篇
  1995年   85篇
  1994年   89篇
  1993年   78篇
  1992年   162篇
  1991年   152篇
  1990年   146篇
  1989年   164篇
  1988年   134篇
  1987年   102篇
  1986年   96篇
  1985年   84篇
  1984年   60篇
  1983年   58篇
  1982年   35篇
  1979年   44篇
  1978年   44篇
  1976年   38篇
  1975年   30篇
  1974年   41篇
  1973年   33篇
  1969年   31篇
  1968年   33篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
991.
The effect of cyclosporin A (CyA) on regenerating liver was investigated in subtotal hepatectomized rats treated with CyA in terms of mitochondrial phosphorylative activity, hepatic energy charge, and serum bilirubin levels. In the CyA-treated hepatectomized group, the energy charge decreased from normal control value of 0.857 to 0.782 at 6 h after hepatectomy. The decreased energy charge, however, gradually increased and returned to 0.842 at 48 h after hepatectomy with no significant changes being observed between CyA-treated and untreated hepatectomized groups. Phosphorylation rate in the CyA-untreated group increased to 142% of the normal control at 24 h and then decreased to 114% at 48 h after hepatectomy. By contrast, phosphorylation rate in the CyA-treated group increased to 144% of the normal control at 24 h, but remained at the high value of 132% (P less than 0.01; compared to the CyA-untreated group) even at 48 h after hepatectomy. Serum total bilirubin levels in the CyA-treated group were significantly higher than those in the CyA-untreated group during all experimental periods. We conclude that CyA does not exert a direct detrimental effect on mitochondrial function and that, despite the marked hyperbilirubinemia induced by CyA, the mitochondrial phosphorylative activity increases adaptively to provide sufficient energy for enhanced ATP-utilizing reactions in an early process of liver regeneration.  相似文献   
992.
The relationship between initial hepatic uptake of indocyanine green (ICG) and hepatic energy status was studied in about 70% hepatectomized rabbits. At 24 h after hepatectomy, the initial plasma disappearance rate (K) and the maximal removal rate (Rmax) of ICG fell to 27 and 26%, respectively, and the mitochondrial phosphorylative activity was enhanced maximally with a concomitant decrease in the energy charge ( (ATP+1/2ADP)/(ATP+ADP+AMP) ) level. Afterward, the initial reduction of ICG removal rate was followed by a rapid increase in week 1 and more gradual return to preoperative values by week 6 after hepatectomy. In the early period after hepatectomy (1-7 days), the mitochondrial phosphorylative activity was the higher the smaller the %K value was, while in the late period after hepatectomy (1-6 weeks), the mitochondrial phosphorylative activity remained unchanged irrespective of increasing %K. It is suggested that the mitochondrial phosphorylative activity may be a better guide to evaluate the functional status of the remnant liver than the initial hepatic uptake of ICG, especially in the early period after hepatoctomy.  相似文献   
993.

Purpose

Postoperative superficial surgical site infection is a major complication in hepatobiliary-pancreatic surgery. We aimed to compare the efficacy of subcuticular sutures versus staples for skin closure in preventing superficial surgical site infection in hepatobiliary-pancreatic surgery.

Methods

Consecutive patients who underwent hepatobiliary-pancreatic surgery at our hospital from October 2006 to March 2011 and from April 2012 to March 2015 were reviewed retrospectively. Superficial surgical site infection incidence was evaluated in patients who received subcuticular sutures and those who received staples for skin closure. Propensity score matching analysis was used to adjust bias from confounding factors.

Results

A total of 691 patients were included. Patients with skin staple closures (n?=?346) were compared with patients with subcuticular suture closures (n?=?345). After a propensity score matching analysis, a significant difference in superficial surgical site infection incidence was found between the skin stapler group (11.3%) and subcuticular sutures group (2.6%). The same comparison was performed by a subgroup analysis and supported this finding in patients after hepatectomy without biliary reconstruction, pancreatoduodenectomy, or open laparotomy surgeries and in patients with body mass index <?25.

Conclusions

Subcuticular suturing after hepatobiliary-pancreatic surgery was more efficacious in reducing postoperative superficial surgical site infection incidence than staples for skin closure.
  相似文献   
994.
S-carboxymethylcysteine (S-CMC) is a mucolytic agent that can prevent respiratory infection by decreasing the attachment of respiratory pathogens to human pharyngeal epithelial cells (HPECs). Streptococcus pneumoniae is a major cause of respiratory infections. A previous study revealed that treatment of S. pneumoniae with S-CMC caused a decrease in the attachment of this bacterium to HPECs. In the present study we found that the effect of S-CMC varied according to hosts and strains. S-CMC treatment altered the surface structure of S. pneumoniae, resulting in a decrease of attachment, without affecting the virulence of the bacteria.  相似文献   
995.
996.
997.
998.
The transduction of cancer cells using recombinant adeno-associated virus (rAAV) occurs with low efficiency, which limits its utility in cancer gene therapy. We have previously sought to enhance rAAV-mediated transduction of cancer cells by applying DNA-damaging stresses. In this study, we examined the effects of the histone deacetylase inhibitor FR901228 on tumor transduction mediated by rAAV types 2 and 5. FR901228 treatment significantly improved the expression of the transgene in four cancer cell lines. The cell surface levels of alpha v integrin, FGF-R1, and PDGF-R were modestly enhanced by the presence of FR901228. These results suggest that the superior transduction induced by the HDAC inhibitor was due to an enhancement of transgene expression rather than increased viral entry. Furthermore, we characterized the association of the acetylated histone H3 in the episomal AAV vector genome by using the chromatin immunoprecipitation assay. The results suggest that the superior transduction may be related to the proposed histone-associated chromatin form of the rAAV concatemer in transduced cells. In the analysis with subcutaneous tumor models, strong enhancement of the transgene expression as well as therapeutic effect was confirmed in vivo. The use of this HDAC inhibitor may enhance the utility of rAAV-mediated transduction strategies for cancer gene therapy.  相似文献   
999.
1000.
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