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   3058篇
  免费   196篇
  国内免费   11篇
耳鼻咽喉   17篇
儿科学   78篇
妇产科学   78篇
基础医学   404篇
口腔科学   9篇
临床医学   295篇
内科学   675篇
皮肤病学   60篇
神经病学   364篇
特种医学   54篇
外科学   252篇
综合类   12篇
一般理论   8篇
预防医学   359篇
眼科学   27篇
药学   230篇
中国医学   8篇
肿瘤学   335篇
  2024年   3篇
  2023年   43篇
  2022年   62篇
  2021年   136篇
  2020年   75篇
  2019年   128篇
  2018年   139篇
  2017年   71篇
  2016年   94篇
  2015年   114篇
  2014年   145篇
  2013年   186篇
  2012年   313篇
  2011年   312篇
  2010年   151篇
  2009年   129篇
  2008年   173篇
  2007年   186篇
  2006年   162篇
  2005年   126篇
  2004年   122篇
  2003年   89篇
  2002年   92篇
  2001年   22篇
  2000年   22篇
  1999年   27篇
  1998年   15篇
  1997年   5篇
  1996年   9篇
  1995年   7篇
  1994年   8篇
  1993年   4篇
  1992年   10篇
  1991年   17篇
  1990年   12篇
  1989年   12篇
  1988年   4篇
  1987年   7篇
  1986年   3篇
  1985年   3篇
  1981年   5篇
  1980年   2篇
  1970年   1篇
  1969年   1篇
  1968年   4篇
  1967年   1篇
  1966年   1篇
  1948年   4篇
  1943年   1篇
  1924年   1篇
排序方式: 共有3265条查询结果,搜索用时 15 毫秒
41.
42.
INTRODUCTIONBouveret's syndrome is a rare variant of gallstone ileus and describes gastric outlet obstruction secondary to an impacted stone in the duodenum. Its presentation is vague and clinical diagnosis is often difficult resulting in a delay in diagnosis.PRESENTATION OF CASEWe report a patient who presented initially with non-specific symptoms and subsequently with features in keeping with acute pancreatitis, but eventually was found to have Bouveret's syndrome.DISCUSSIONDifferent treatment strategies are discussed. Although endoscopic treatment combined with many newer modalities like lithotripsy have been tried, surgery remains the definitive management in the vast majority of cases.CONCLUSIONBouveret's syndrome is a rare condition, can also present as pancreatitis and often difficult to diagnose initially, but with appropriate treatment has a good outcome.  相似文献   
43.
44.
Objectives: To evaluate the efficacy of Oraqix® during scaling and root planing (SRP) in comparison with 20% benzocaine and placebo. Study Design: 15 patients requiring 4 sessions of SRP were enrolled. For each patient, Oraqix®, Hurricaine®, vaseline or no anesthetic product were randomly assigned each to a quadrant. Treatment pain was evaluated on a 100 mm Visual Analog Scale (VAS) and on a Verbal Rating Scale (VRS). The amount of product administered, the need to re-anesthetise, patient and operator satisfaction and the onset of side-effects were also recorded. Results: Oraqix® was significantly better than nothing, with a reduction of VAS score to 13.3 units, but without significant differences with Vaseline or Hurricaine®. Oraqix® was better in VRS reduction than not using any anesthetic (p=0.001) or using vaseline (p=0.024), but similar to Hurricaine® (p=0.232). Conclusions: Oraqix® effectively controls pain in SRP procedures, with few side-effects and a good acceptance on the part of patients and clinicians. Key words:Controlled clinical trial, topical anesthetic, scaling and root planing.  相似文献   
45.
Although their primary therapeutic indications are different, aminobisphosphonates and statins target enzymes in the mevalonate pathway, which is critical for bone homeostasis. Previous studies have shown that some polymorphisms of the gene encoding farnesyl diphosphate synthase (FDPS), the main target of aminobisphosphonates, modulate the response to these drugs. In this study, we explored whether those single nucleotide polymorphisms (SNPs) also influence the changes in bone mineral density (BMD) following therapy with statins. Sixty-six patients with coronary heart disease were studied at baseline and after 1-year therapy with atorvastatin. BMD was measured by DXA. Three SNPs of the FDPS gene (rs2297480, rs11264359 and rs17367421) were analyzed by using Taqman assays. The results showed that there was no association between the SNPs and basal BMD. However, rs2297480 and rs11264359 alleles, which are in linkage disequilibrium, were associated with changes in hip BMD following atorvastatin therapy. Thus, patients with AA genotype at the rs2297480 locus had a 0.8 ± 0.8 % increase in BMD at the femoral neck, whereas in patients with AC/CC genotypes, BMD showed a 2.3 ± 0.8 % decrease (p = 0.02). Similar results were obtained regarding changes of BMD at the femoral trochanter and when alleles at the rs11264359 locus were analyzed. However, there was no association between BMD and rs17367421 alleles. In conclusion, these results suggest that polymorphisms of the FDPS gene may influence the bone response to various drugs targeting the mevalonate pathway, including not only aminobisphosphonates but also statins.  相似文献   
46.
Recent research has indicated that vicarious learning can lead to increases in children’s fear beliefs and avoidance preferences for stimuli and that these fear responses can subsequently be reversed using positive modeling (counterconditioning). The current study investigated children’s vicariously acquired avoidance behavior, physiological responses (heart rate), and attentional bias for stimuli and whether these could also be reduced via counterconditioning. Ninety-six (49 boys, 47 girls) 7- to 11-year-olds received vicarious fear learning for novel stimuli and were then randomly assigned to a counterconditioning, extinction, or control group. Fear beliefs and avoidance preferences were measured pre- and post-learning, whereas avoidance behavior, heart rate, and attentional bias were all measured post-learning. Control group children showed increases in fear beliefs and avoidance preferences for animals seen in vicarious fear learning trials. In addition, significantly greater avoidance behavior, heart rate responding, and attentional bias were observed for these animals compared to a control animal. In contrast, vicariously acquired avoidance preferences of children in the counterconditioning group were significantly reduced post-positive modeling, and these children also did not show the heightened heart rate responding to fear-paired animals. Children in the extinction group demonstrated comparable responses to the control group; thus the extinction procedure showed no effect on any fear measures. The findings suggest that counterconditioning with positive modelling can be used as an effective early intervention to reduce the behavioral and physiological effects of vicarious fear learning in childhood.  相似文献   
47.
48.
49.
50.
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