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   4020篇
  免费   327篇
  国内免费   24篇
耳鼻咽喉   35篇
儿科学   147篇
妇产科学   61篇
基础医学   731篇
口腔科学   32篇
临床医学   453篇
内科学   852篇
皮肤病学   66篇
神经病学   476篇
特种医学   74篇
外科学   442篇
综合类   14篇
一般理论   2篇
预防医学   369篇
眼科学   42篇
药学   277篇
中国医学   9篇
肿瘤学   289篇
  2024年   2篇
  2023年   40篇
  2022年   56篇
  2021年   101篇
  2020年   60篇
  2019年   102篇
  2018年   111篇
  2017年   73篇
  2016年   81篇
  2015年   105篇
  2014年   154篇
  2013年   203篇
  2012年   311篇
  2011年   342篇
  2010年   171篇
  2009年   170篇
  2008年   290篇
  2007年   285篇
  2006年   283篇
  2005年   278篇
  2004年   259篇
  2003年   279篇
  2002年   220篇
  2001年   29篇
  2000年   18篇
  1999年   32篇
  1998年   40篇
  1997年   51篇
  1996年   31篇
  1995年   23篇
  1994年   31篇
  1993年   33篇
  1992年   7篇
  1991年   14篇
  1990年   10篇
  1989年   8篇
  1988年   3篇
  1987年   3篇
  1986年   12篇
  1985年   2篇
  1984年   10篇
  1983年   4篇
  1982年   8篇
  1981年   6篇
  1980年   5篇
  1979年   2篇
  1978年   3篇
  1977年   2篇
  1964年   1篇
  1962年   1篇
排序方式: 共有4371条查询结果,搜索用时 15 毫秒
101.
102.
This multicentre prospective randomised trial compared the efficacy and safety of two doses of thalidomide in patients with relapsed or refractory myeloma. The study was designed to test the non-inferior efficacy and to confirm the better tolerability of low-dose thalidomide as compared to a higher dose. Four hundred patients were randomly assigned to receive either 100 or 400 mg/day of thalidomide. Dexamethasone treatment was added in both arms for patients with stable disease or treatment failure at 12 weeks. The primary endpoint was 1-year overall survival (OS). Thalidomide 100 mg/day was better tolerated than 400 mg/day with less high-grade somnolence, constipation, nausea/vomiting and peripheral neuropathy (P < 0.001, P = 0.007, P = 0.03 and P = 0.007, respectively). In the per-protocol population (PP), the estimated 1-year OS rates were of 74.5% (n = 149) and 67.3% (n = 156) in the 400 and 100 groups, respectively. The upper limit of the difference between these rates was of 15.6% higher than the non-inferiority acceptable limit of 12.75%, and the hypothesis of non-inferiority of 100 could not be established (P = 0.14). On the other hand, when intent-to-treat (ITT) population was analysed, the non-inferiority was demonstrated because the 1-year OS rates were of 72.8% (n = 195) and 68.8% (n = 205) in the same groups, leading to an upper limit of the difference of 11.49% lower than the non-inferiority acceptable limit. In addition, in patients alive 12 weeks postrandomisation and those who received thalidomide plus dexamethasone, there were no significant differences in response rates, time to progression, progression-free survival and OS between the two groups. Collectively, low-dose thalidomide 100 mg/day has significant activity in advanced myeloma with an improved safety profile and can be a good salvage therapy in combination with dexamethasone.  相似文献   
103.
Aims Previous research has shown that consistently not responding to alcohol‐related stimuli in a go/no‐go training procedure reduces drinking behaviour. This study aimed to examine further the mechanisms underlying this go/no‐go training effect. Design, setting and participants Fifty‐seven heavy drinkers were assigned randomly to two training conditions: in the beer/no‐go condition, alcohol‐related stimuli were always paired with a stopping response, while in the beer/go condition participants always responded to alcohol‐related stimuli. Participants were tested individually in a laboratory at Maastricht University. Measurements Weekly alcohol intake, implicit attitudes towards beer, approach–avoidance action tendencies towards beer and response inhibition were measured before and after the training. Findings Results showed a significant reduction in both implicit attitudes (P = 0.03) and alcohol intake (P = 0.02) in the beer/no‐go condition, but not in the beer/go condition. There were no significant training effects on action tendencies or response inhibition. Conclusions Repeatedly stopping pre‐potent responses towards alcohol‐related stimuli reduces excessive alcohol use via a devaluation of alcohol‐related stimuli rather than via increased inhibitory control over alcohol‐related responses.  相似文献   
104.
In addition to its role in the regulation of artery contraction, Rho kinase (ROCK) was reported to be involved in the cytosolic calcium response to vasoconstrictor agonists in rat aorta and superior mesenteric artery (SMA). However, it remains to be determined whether ROCK also contributes to calcium signaling in resistance arteries, which play a major role in blood pressure regulation. The investigation of the effect of ROCK inhibition on the calcium and contractile responses of rat resistance mesenteric artery (RMA), in comparison with aorta and SMA, indicated that the calcium response to noradrenaline was inhibited by the ROCK inhibitor Y-27632 in aorta and SMA but not in RMA. The effect of Y-27632 on the calcium signal was unaffected by cytochalasin-D. ROCK activation in noradrenaline-stimulated arteries was confirmed by the inhibition of myosin light chain phosphorylation by Y-27632. Moreover, noradrenaline-induced calcium signaling was similarly inhibited by nimodipine in aorta, SMA and RMA, but nimodipine sensitivity of the contraction increased from the aorta to the RMA, suggesting that the contraction was controlled by different sources of calcium. In pressurized RMA, Y-27632 and H-1152 depressed pressure-induced calcium responses and abolished myogenic contraction. These results stress the important differences in calcium signaling between conductance and resistance arteries.  相似文献   
105.
106.
The new incretin-based therapies, dipeptidyl peptidase-4 (DPP4) inhibitors and glucagon like peptide 1 (GLP1) receptor agonists are widely used for the treatment of type 2 diabetes because of their glucose-lowering capacity with low risk of hypoglycemia. As they are weight neutral or induce weight loss in this mostly overweight population, they are popular among clinicians and patients alike. Nonetheless, concerns have been raised about GLP1's trophic effects. While increased β cell mass observed in rodents sounds appealing for treatment of diabetes, there was also an increased incidence of medullary thyroid cancer (MTC) in some species. We reviewed literature available in the Medline database until March 2012. Safety signals have emerged for MTC and pancreatic carcinoma from adverse event databases in the United States and Europe. Considering the relatively short duration of these studies, it is more likely that premalignant lesions are stimulated in presence of GLP1, rather than new neoplasms induced. Moreover, interpreting results of animal studies is difficult because of species-specific differences in presence and density of GLP1 receptors. Furthermore, data are emerging suggesting beneficial effects of GLP1 on colon and breast cancer. In conclusion, presently, the benefits of using DPP4 inhibitors or GLP1 receptor agonists for treatment of type 2 diabetes outweigh the risks. Nonetheless, their safety profile should be monitored and their indications should be widened cautiously. At present they remain contra-indicated in patients with a personal or family history of MTC or multiple endocrine neoplasia type 2.  相似文献   
107.
Heart failure self-care is vital to achieving clinical stability and improved health outcomes. Yet despite the attention it has been given, in both research and clinical practice, effective self-care remains elusive. It is recognised that there are many patient factors that impact on attaining effective self-care skills. Systematic research is warranted to resolve the knowledge gap of how patients process information and develop the necessary self-care skills. In addition, sound screening tools are needed to assess factors that hinder the development of effective heart failure self-care skills. In this manner, education and support strategies can be applied on an individualised needs basis to enhance health outcomes.  相似文献   
108.
109.

Background

The request to lose weight is expanding not only in obese and morbidly obese patients but also in overweight patients affected by co-morbidities as diabetes and hypertension and who do not tolerate diet regimen or lifestyle changes. The aim of this study is a multicenter evaluation of outcomes of intragastric balloon in overweight patients.

Methods

Patients (BMI 27–30 kg/m2) treated with a BioEnterics Intragastric Balloon (BIB) between 1996 and 2010 were extracted from the database of the participating centres in Rome (Italy), Liège (Belgium) and Madrid (Spain). Primary endpoints were the efficacy and safety at 6 and 42 months from balloon positioning. Secondary endpoints included resolution of co-morbidities.

Results

A total of 261 patients were included in this study. The most common indication for balloon placement was a psychological disorder (54 %). Mean body mass index (BMI) fell from 28.6?±?0.4 at baseline to 25.4?±?2.6 kg/m2 at 6 months and to 27.0?±?3.1 kg/m2 at 3 years from BIB removal. The mean %EWL was 55.6 % at 6 months and 29.1 % at 3 years. Forty-seven patients (18 %) had complications associated with placement of the intragastric balloon (leak?=?28, intolerance?=?14, duodenal ulcer?=?2, gastritis?=?1, oesophagitis?=?1, duodenal polyps?=?1). The rate of patients with hypertension decreased from 29 % at baseline to 16 % at 3 years. Diabetes decreased from 15 to 10 %, dyslipidaemia decreased from 20 to 18 %, hypercholesterolaemia decreased from 32 to 21 % and osteoarthropathy decreased from 25 to 13 %.

Conclusions

The intragastric balloon is safe and effective in overweight patients, helping to reduce progression to obesity and decreasing the prevalence of a number of important co-morbidities.  相似文献   
110.
Assessment of the early stages of fracture healing via X‐rays and computed tomography is limited by the low radio‐opacity of cartilage. We validated a method of contrast‐enhanced computed tomography (CECT) for non‐destructive identification of cartilage within a healing fracture callus. Closed, stabilized fractures in femora of C57BL/6 mice were harvested on post‐operative day 9.5 and imaged ex vivo with micro‐computed tomography (µCT) before and after incubation in a cationic contrast agent that preferentially accumulates in cartilage due to the high concentration of sulfated glycosaminoglycans in the tissue. Co‐registration of the pre‐ and post‐incubation images, followed by image subtraction, enabled two‐ and three‐dimensional delineation of mineralized tissue, soft callus, and cartilage. The areas of cartilage and callus identified with CECT were compared to those identified with the gold‐standard method of histomorphometry. No difference was found between the areas of cartilage measured by the two methods (p = 0.999). Callus area measured by CECT was smaller than, but strongly predictive of (R2 = 0.80, p < 0.001), the corresponding histomorphometric measurements. CECT also enabled qualitative identification of mineralized cartilage. These findings indicate that the CECT method provides accurate, quantitative, and non‐destructive visualization of the shape and composition of the fracture callus, even during the early stages of repair when little mineralized tissue is present. The non‐destructive nature of this method would allow subsequent analyses, such as mechanical testing, to be performed on the callus, thus enabling higher‐throughput, comprehensive investigations of bone healing. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 567–573, 2013  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