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   2911篇
  免费   161篇
  国内免费   11篇
耳鼻咽喉   9篇
儿科学   93篇
妇产科学   71篇
基础医学   292篇
口腔科学   69篇
临床医学   256篇
内科学   693篇
皮肤病学   45篇
神经病学   228篇
特种医学   83篇
外科学   544篇
综合类   25篇
预防医学   175篇
眼科学   75篇
药学   170篇
中国医学   17篇
肿瘤学   238篇
  2023年   23篇
  2022年   45篇
  2021年   87篇
  2020年   59篇
  2019年   94篇
  2018年   78篇
  2017年   60篇
  2016年   74篇
  2015年   77篇
  2014年   89篇
  2013年   133篇
  2012年   146篇
  2011年   159篇
  2010年   92篇
  2009年   75篇
  2008年   117篇
  2007年   131篇
  2006年   93篇
  2005年   85篇
  2004年   95篇
  2003年   83篇
  2002年   93篇
  2001年   72篇
  2000年   81篇
  1999年   64篇
  1998年   25篇
  1997年   18篇
  1996年   17篇
  1995年   22篇
  1993年   14篇
  1992年   73篇
  1991年   57篇
  1990年   55篇
  1989年   67篇
  1988年   66篇
  1987年   68篇
  1986年   62篇
  1985年   52篇
  1984年   36篇
  1983年   22篇
  1979年   29篇
  1978年   14篇
  1977年   15篇
  1976年   14篇
  1975年   14篇
  1972年   15篇
  1971年   18篇
  1970年   13篇
  1969年   13篇
  1968年   13篇
排序方式: 共有3083条查询结果,搜索用时 250 毫秒
101.
Journal of Neurology - The Present study was conducted to systematically review the effect of the melatonin on sleep quality. We summarized evidence from randomized clinical trials (RCTs) that...  相似文献   
102.
103.
Pancreatic tumors are chemoresistant and malignant, and there are very few therapeutic options for pancreatic cancer, as the disease is normally diagnosed at an advanced stage. Although attempts have been made to develop vaccine therapies for pancreatic cancer for a couple of decades, none of the resultant protocols or regimens have succeeded in improving the clinical outcomes of patients. We herein review vaccines tested within the past few years, including peptide, biological and multiple vaccines, and describe the three sets of criteria used to evaluate the therapeutic activity of vaccines in solid tumors.  相似文献   
104.

Background

Delayed gastric emptying (DGE) is a common complication of pancreaticoduodenectomy. We determined the efficiency of a new reconstruction technique, designed to preserve motilin-secreting cells and maximize the utility of their receptors, in reducing the incidence of DGE after pancreaticoduodenectomy.

Methods

From April 2005 to September 2014, 217 consecutive patients underwent pancreaticoduodenectomy at our institution. Nine patients who underwent total pancreatectomy were excluded. We compared outcomes between patients who underwent pancreaticoduodenectomy with resection of the pyloric ring followed by proximal Roux-en-y gastrojejunal anastomosis (group I, n?=?90) and patients who underwent standard pancreaticoduodenectomy with the orthotopic reconstruction technique (group II, n?=?118).

Results

Overall and clinically relevant rates of DGE were significantly lower in group I than in group II (10 and 2.2 % vs. 57 and 24 %, respectively; p?<?0.05). Length of hospital stay as a result of DGE was shorter in group I than in group II. In univariate analysis, older age, comorbidities, ASA grade 4, operative time, preoperative diabetes, standard reconstruction technique, and postoperative complications were significant risk factors for DGE. In multivariate analysis, older age, standard technique, and postoperative complications were independent risk factors for DGE.

Conclusion

Our new reconstruction technique reduces the occurrence of DGE after pancreaticoduodenectomy.
  相似文献   
105.

Purpose

Sepantronium bromide (YM155) is a hydrophilic quaternary compound that cannot be administered orally due to its low oral bioavailability; it is furthermore rapidly eliminated via the kidneys. The current study aims at improving the pharmacokinetic profile of YM155 by its formulation in immunoliposomes that can achieve its enhanced delivery into tumor tissue and facilitate uptake in neuroblastoma cancer cells.

Methods

PEGylated YM155 loaded liposomes composed of DPPC, cholesterol and DSPE-PEG2000 were prepared via passive film-hydration and extrusion method. Targeted (i.e. immuno-)liposomes were prepared by surface functionalization with SATA modified monoclonal anti-disialoganglioside (GD2) antibodies. Liposomes were characterized based on their size, charge, antibody coupling and YM155 encapsulation efficiency, and stability. Flow cytometry analysis and confocal microscopy were performed on IMR32 and KCNR neuroblastoma cell lines. The efficacy of developed formulations were assessed by in-vitro toxicity assays. A pilot pharmacokinetic analysis was performed to assess plasma circulation and tumor accumulation profiles of the developed liposomal formulations.

Results

YM155 loaded immunoliposomes had a size of 170 nm and zeta potential of ?10 mV, with an antibody coupling efficiency of 60% andYM155 encapsulation efficiency of14%. Targeted and control liposomal formulations were found to have similar YM155 release rates in a release medium containing 50% serum. An in-vitro toxicity study on KCNR cells showed less toxicity for immunoliposomes as compared to free YM155. In-vivo pharmacokinetic evaluation of YM155 liposomes showed prolonged blood circulation and significantly increased half-lives of liposomal YM155 in tumor tissue, as compared to a bolus injection of free YM155.

Conclusions

YM155 loaded immunoliposomes were successfully formulated and characterized, and initial in-vivo results show their potential for improving the circulation time and tumor accumulation of YM155.
  相似文献   
106.
107.
108.
A 13-year-old boy was referred to us for investigation of a giant liver mass, approximately 16 cm in diameter. Sonographically guided percutaneous needle biopsy was performed and histological examination revealed a fetal-type hepatoblastoma. After four courses of chemotherapy, we performed a left hepatic trisegmentectomy. Follow-up computed tomography, 55 months after the surgery, showed a 1-cm tumor on the route of the preoperative needle biopsy. A second laparotomy revealed a peritonealised tumor, which was excised. The histology of this tumor was identical to that of the primary hepatoblastoma. To our knowledge, this is only the second report of needle tract implantation of hepatoblastoma after percutaneous needle biopsy.  相似文献   
109.
110.
Aldo-keto reductase 1C3 (AKR1C3, EC 1.1.1.188) metabolises steroid hormones, prostaglandins and xenobiotics, and activates the dinitrobenzamide mustard prodrug PR-104A by reducing it to hydroxylamine PR-104H. Here, we describe a functional assay for AKR1C3 in cells using the fluorogenic probe coumberone (a substrate for all AKR1C isoforms) in conjunction with a specific inhibitor of AKR1C3, the morpholylurea SN34037. We use this assay to evaluate AKR1C3 activity and PR-104A sensitivity in human leukaemia cells. SN34037-sensitive reduction of coumberone to fluorescent coumberol correlated with AKR1C3 protein expression by immunoblotting in a panel of seven diverse human leukaemia cell lines, and with SN34037-sensitive reduction of PR-104A to PR-104H. SN34037 inhibited aerobic cytotoxicity of PR-104A in high-AKR1C3 TF1 erythroleukaemia cells, but not in low-AKR1C3 Nalm6 pre-B cell acute lymphocytic leukaemia (B-ALL) cells, although variation in PR-104H sensitivity confounded the relationship between AKR1C3 activity and PR-104A sensitivity across the cell line panel. AKR1C3 mRNA expression showed wide variation between leukaemia patients, with consistently higher levels in T-ALL than B-ALL. In short term cultures from patient-derived paediatric ALL xenografts, PR-104A was more potent in T-ALL than B-ALL lines, and PR-104A cytotoxicity was significantly inhibited by SN34037 in T-ALL but not B-ALL. Overall, the results demonstrate that SN34037-sensitive coumberone reduction provides a rapid and specific assay for AKR1C3 activity in cells, with potential utility for identifying PR-104A-responsive leukaemias. However, variations in PR-104H sensitivity indicate the need for additional biomarkers for patient stratification.  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