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   3796篇
  免费   325篇
  国内免费   74篇
耳鼻咽喉   122篇
儿科学   87篇
妇产科学   72篇
基础医学   481篇
口腔科学   93篇
临床医学   357篇
内科学   754篇
皮肤病学   90篇
神经病学   262篇
特种医学   245篇
外科学   627篇
综合类   157篇
一般理论   2篇
预防医学   135篇
眼科学   89篇
药学   296篇
中国医学   31篇
肿瘤学   295篇
  2023年   25篇
  2022年   70篇
  2021年   122篇
  2020年   68篇
  2019年   73篇
  2018年   97篇
  2017年   82篇
  2016年   122篇
  2015年   133篇
  2014年   126篇
  2013年   196篇
  2012年   243篇
  2011年   231篇
  2010年   165篇
  2009年   134篇
  2008年   162篇
  2007年   223篇
  2006年   157篇
  2005年   160篇
  2004年   165篇
  2003年   124篇
  2002年   116篇
  2001年   97篇
  2000年   108篇
  1999年   82篇
  1998年   80篇
  1997年   70篇
  1996年   73篇
  1995年   54篇
  1994年   48篇
  1993年   33篇
  1992年   34篇
  1991年   35篇
  1990年   38篇
  1989年   69篇
  1988年   49篇
  1987年   45篇
  1986年   38篇
  1985年   33篇
  1984年   33篇
  1983年   17篇
  1982年   21篇
  1981年   19篇
  1980年   26篇
  1979年   10篇
  1978年   12篇
  1977年   12篇
  1976年   12篇
  1975年   11篇
  1968年   6篇
排序方式: 共有4195条查询结果,搜索用时 15 毫秒
71.

Background  

An aqueous extract of multi-hypoglycemic herbs of Panax ginseng C.A.Meyer, Pueraria lobata, Dioscorea batatas Decaisne, Rehmannia glutinosa, Amomum cadamomum Linné, Poncirus fructus and Evodia officinalis was investigated for its anti-diabetic effects in cell and animal models.  相似文献   
72.
Even with the increasing importance being placed on research into immigrant elders’ healthcare use as countries change their policies to reflect their increasing immigrant and aging populations, little research has examined changes in healthcare use disparities between immigrant and native elders in relation to these policy changes. To fill this gap in the literature, this study examined healthcare disparities in relation to the welfare reform that the US implemented in 1996 and then compared significant indicators of immigrants’ healthcare use during the pre- and post-reform periods. The difference-in-difference (DD) analyses and post hoc probing of the DD analyses were used in multivariate logistic regression of the National Health Information Survey data that were pooled for the pre- and post-reform periods. The results revealed that while inequalities in healthcare existed before the reform, they significantly increased after the reform. A further test showed that the changes in the inequalities were significant among relatively long-stay immigrants, but not significant among immigrants who entered the US before the reform and thus were exempted from the reform restrictions. During the pre-reform period, insurance, employment, sex, and race/ethnicity were related to healthcare use; however, the enabling factors (i.e., insurance, income, and education) and social structural factors (i.e., marital status, family structure, length of US residency, race/ethnicity, and geographical region) explained the post-reform immigrants’ healthcare use, while controlling for healthcare needs factors. These findings suggest that welfare reform may be the driving force of inequalities in healthcare.  相似文献   
73.
Chronic kidney disease (CKD) is caused by dysfunctional kidneys, which result in complications like cardiovascular diseases. Chronic kidney disease-induced pathophysiological conditions decrease efficacy of autologous mesenchymal stem/stromal cell (MSC)-based therapy by reducing MSC functionality. To enhance therapeutic potential in patients with CKD, we isolated exosomes derived from melatonin-treated healthy MSCs (MT exosomes) and assessed the biological functions of MT exosome–treated MSCs isolated from patients with CKD (CKD-MSCs). Treatment with melatonin increased the expression of cellular prion protein (PrPC) in exosomes isolated from MSCs through the upregulation of miR-4516. Treatment with MT exosomes protected mitochondrial function, cellular senescence, and proliferative potential of CKD-MSCs. MT exosomes significantly increased the level of angiogenesis-associated proteins in CKD-MSCs. In a murine hindlimb ischemia model with CKD, MT exosome–treated CKD-MSCs improved functional recovery and vessel repair. These findings elucidate the regenerative potential of MT exosome–treated CKD-MSCs via the miR-4516-PrPC signaling axis. This study suggests that the treatment of CKD-MSCs with MT exosomes might be a powerful strategy for developing autologous MSC-based therapeutics for patients with CKD. Furthermore, miR-4516 and PrPC could be key molecules for enhancing the regenerative potential of MSCs in ischemic diseases.  相似文献   
74.
75.
76.
77.
78.
Background: The use and timing of steroids in the management of acute tubulointerstitial nephritis (ATIN) remains debatable. Aims: To determine the incidence and aetiology of ATIN in our unit, and to examine trends in the use of steroids and their impact on renal outcomes. Methods: Patients with a histological diagnosis of ATIN over a 9‐year period were identified and divided into steroid‐treated (StG) and steroid‐naïve groups (SnG). Mean change in estimated glomerular filtration rate (eGFR) was determined. Results: Forty‐nine patients had ATIN as their main diagnosis, 67% of cases were drug‐induced, and proton pump inhibitors (PPI) were the second commonest implicated drug category. Majority (75%) of patients received steroids, and eGFR improved to a significantly greater degree in these steroid‐treated patients (3.4‐fold improvement vs 2.0‐fold in SnG; P < 0.05, unpaired t‐test). Despite comparable eGFR at presentation (StG: 11.7; SnG: 15.4), steroid‐treated patients were less likely to receive dialysis, although not significantly so (OR 0.27; 95% CI 0.06–1.15, P = 0.066, chi‐squared test). However, there was no significant relation between the degree of eGFR improvement and delay in starting steroids (Pearson r = ?0.25, P > 0.45), and no difference in eGFR at the time of last follow‐up (StG: 33 ± 3; SnG: 32 ± 7; P > 0.9, unpaired t‐test). Conclusion: StG patients had a greater degree of improvement in renal function, but with no correlation between degree of improvement in eGFR and delay in starting steroids, and similar eGFR values at final follow‐up. PPI were the second commonest drug category among drug‐induced cases.  相似文献   
79.
80.
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