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   1360篇
  免费   123篇
  国内免费   3篇
耳鼻咽喉   5篇
儿科学   73篇
妇产科学   23篇
基础医学   224篇
口腔科学   15篇
临床医学   139篇
内科学   292篇
皮肤病学   22篇
神经病学   46篇
特种医学   90篇
外科学   116篇
综合类   33篇
预防医学   116篇
眼科学   39篇
药学   133篇
中国医学   1篇
肿瘤学   119篇
  2021年   32篇
  2020年   12篇
  2019年   23篇
  2018年   31篇
  2017年   22篇
  2016年   25篇
  2015年   26篇
  2014年   43篇
  2013年   57篇
  2012年   62篇
  2011年   63篇
  2010年   33篇
  2009年   39篇
  2008年   56篇
  2007年   57篇
  2006年   55篇
  2005年   60篇
  2004年   42篇
  2003年   42篇
  2002年   36篇
  2001年   38篇
  2000年   36篇
  1999年   46篇
  1998年   32篇
  1997年   30篇
  1996年   21篇
  1995年   18篇
  1994年   14篇
  1993年   15篇
  1992年   19篇
  1991年   23篇
  1990年   29篇
  1989年   27篇
  1988年   37篇
  1987年   32篇
  1986年   28篇
  1985年   44篇
  1984年   24篇
  1983年   14篇
  1982年   14篇
  1981年   12篇
  1980年   9篇
  1979年   12篇
  1978年   9篇
  1977年   6篇
  1976年   8篇
  1975年   6篇
  1973年   5篇
  1972年   9篇
  1971年   10篇
排序方式: 共有1486条查询结果,搜索用时 15 毫秒
1.
European Journal of Nutrition - The French Nutri-Bébé 2013 study aimed to assess the nutritional intake of infants and young children in comparison with the recommendations of the 2013...  相似文献   
2.
3.
The objective of this study was to assess the in vivo fate of poly(2-(dimethylamino)ethyl methacrylate) (pDMAEMA)-based polyplexes after intravenous administration into mice. Circulation kinetics and tissue distribution in terms of plasmid localization and transfection efficiency were assessed. To gain more insight into the observed biodistribution and gene expression profile, the interaction of pDMAEMA-based polyplexes with blood components (erythrocytes and albumin) was investigated in vitro. In the case of i.v. injection of positively charged polyplexes at a dose of 30 microg DNA most of the radioactivity was found in the lungs and the liver 60 min after injection. In the case of pDMAEMA/DNA polyplexes with a negative charge, uptake occurred mainly by the liver. Administration of positively charged complexes at a 30 microg DNA dose resulted in reporter gene expression primarily in the lungs. Injection of negatively charged complexes and naked plasmid did not result in luciferase expression in any of the organs examined. In vitro turbidity experiments showed the induction of a charge dependent aggregation process upon addition of albumin to the polyplexes pointing out to the involvement of aggregate formation in the dominant lung uptake of the positively charged polyplexes. Also, incubations of polyplexes after pre-incubation with a physiological concentration of albumin with washed erythrocytes confirmed that polyplexes induce the formation of extremely large structures. This paper underlines the need for the design of systems with reduced interaction with blood components to promote the delivery of DNA to target tissues outside the lungs.  相似文献   
4.
A randomized two-way crossover study was conducted in 12 healthy volunteers to assess the effect of food on the pharmacokinetics of quinapril (CI-906) and its active metabolite, CI-928, after quinapril dosing. Forty-milligram oral quinapril doses were administered in a fasted or a fed state with a one-week washout period between treatments. No significant treatment differences were observed in quinapril and CI-928 values for maximum plasma concentration, area under the plasma concentration-time curve, or percentage of dose excreted in the urine. Small but significant increases of less than 0.5 hour in quinapril and CI-928 tmax values were observed after consumption of food. The pharmacokinetic profiles of quinapril and CI-928 were not significantly altered by the administration of food.  相似文献   
5.
A simple, precise method has been developed for assessing neutrophil secretory responses (release of vitamin B12 binding protein from specific granules) to challenge of aliquots of whole blood with the bacterial chemotactic peptide N-formylmethionyl-leucyl-phenylalanine (fMLP). Dose-response studies performed on blood from normal healthy volunteers showed higher maximal secretory responses in males than females (33.3 +/- SEM 2.2 vs. 27.4 +/- 2.5, P less than .005) a left shift in dose-response curves after feeding compared to fasting (P less than .005), spontaneous up-regulation of responses in blood incubated at 37 degrees C for 1 h, and marked upregulation in response to preincubation with endotoxin. This whole blood challenge method may be used to study neutrophil responses in groups of individuals or patients without the confounding effects of changes in cell responses resulting from cell isolation procedures. The method may also be used as a bioassay for neutrophil-activating factors.  相似文献   
6.
Calciphylaxis – a topical overview   总被引:3,自引:0,他引:3  
'Calciphylaxis', a calcification syndrome associated with ischaemic cutaneous necrosis, is acquired naturally in humans in disease states. It is a life and limb-threatening complication, usually observed in patients with renal disease and secondary hyperparathyroidism, but known to occur in the absence of renal or parathyroid disease. The reported mortality rate, which ranges from 60-80%, relates to wound infection, sepsis and organ failure. It is a small-vessel vasculopathy, which is estimated to occur in about 4% of haemodialysis patients. Clinically, violaceous, reticulate areas of cutaneous necrosis and eschar may be evident, particularly in the extremities. In addition to the clinical picture, a raised calcium phosphorous product, an elevated parathyroid hormone level, radiographic evidence of vessel and soft-tissue calcification and the finding of mural calcification affecting small arteries and arterioles on histopathology help to confirm the diagnosis of this entity which generally has a poor prognosis. A high index of suspicion and an active multidisciplinary management approach, with rigorous attention to wound care and prevention of sepsis, are vital in the management of these patients. In this overview, we discuss the pathophysiology, clinical features and associations, risk factors, diagnosis and management issues relating to calciphylaxis.  相似文献   
7.
8.
Cisplatin and its analogs have become important components of chemotherapeutic regimens for the treatment of solid tumors, however, their overall effectiveness is limited by the emergence of drug-resistant tumor cells. Resistance to the platinum drugs is multifactorial consisting of mechanisms that prevent the formation of lethal platinum-DNA adducts and mechanisms that operate downstream of the drug/target interaction to promote cell survival. Continued progress in the study of the drug resistance phenotype as well as the development of new platinum analogs may eventually lead to improved therapies and increased survival rates.  相似文献   
9.
Summary: The objective of this study was to assess the efficacy and safety aspects of performing transcervical endometrial resection (T.C.R.E.) on a selected group of 278 patients with menstrual disorders under local analgesia (intracervical block) only. Patient acceptance of the procedure was high, with only 3 cases not completed due to insufficient analgesia (1.07%), although a further 9 (3.2%) were completed with the help of intravenous sedation. Patient satisfaction at 4 months was 90%. There were 4 perforations (1.4%), but no laparotomy was required. Five cases (1.7%) of haemorrhage required a Foley catheter, with 1 needing a transfusion. There was no case of clinically evident glycine overload. Twelve patients required an overnight stay.
Patient acceptance of T.C.R.E. under local analgesia, and the incidence of major complications, compared favourably with other published series, including a series of 330 cases performed concurrently by the same operators under general anaesthesia.  相似文献   
10.
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