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   6536篇
  免费   488篇
  国内免费   23篇
耳鼻咽喉   41篇
儿科学   224篇
妇产科学   199篇
基础医学   870篇
口腔科学   102篇
临床医学   1114篇
内科学   1262篇
皮肤病学   103篇
神经病学   561篇
特种医学   131篇
外科学   583篇
综合类   54篇
一般理论   9篇
预防医学   777篇
眼科学   104篇
药学   457篇
中国医学   8篇
肿瘤学   448篇
  2024年   6篇
  2023年   47篇
  2022年   81篇
  2021年   193篇
  2020年   141篇
  2019年   196篇
  2018年   194篇
  2017年   160篇
  2016年   167篇
  2015年   173篇
  2014年   235篇
  2013年   358篇
  2012年   505篇
  2011年   485篇
  2010年   291篇
  2009年   237篇
  2008年   453篇
  2007年   451篇
  2006年   442篇
  2005年   420篇
  2004年   394篇
  2003年   376篇
  2002年   306篇
  2001年   55篇
  2000年   62篇
  1999年   66篇
  1998年   71篇
  1997年   39篇
  1996年   43篇
  1995年   46篇
  1994年   27篇
  1993年   28篇
  1992年   42篇
  1991年   25篇
  1990年   28篇
  1989年   24篇
  1988年   37篇
  1987年   19篇
  1986年   17篇
  1985年   19篇
  1984年   11篇
  1983年   16篇
  1982年   8篇
  1981年   6篇
  1980年   12篇
  1979年   3篇
  1978年   8篇
  1977年   3篇
  1967年   4篇
  1964年   3篇
排序方式: 共有7047条查询结果,搜索用时 15 毫秒
1.
Lessons Learned
  • The combination of trametinib and sorafenib has an acceptable safety profile, albeit at doses lower than approved for monotherapy.
  • Maximum tolerated dose is trametinib 1.5 mg daily and sorafenib 200 mg twice daily.
  • The limited anticancer activity observed in this unselected patient population does not support further exploration of trametinib plus sorafenib in patients with hepatocellular carcinoma.
BackgroundThe RAS/RAF/MEK/ERK signaling pathway is associated with proliferation and progression of hepatocellular carcinoma (HCC). Preclinical data suggest that paradoxical activation of the MAPK pathway may be one of the resistance mechanisms of sorafenib; therefore, we evaluated trametinib plus sorafenib in HCC.MethodsThis was a phase I study with a 3+3 design in patients with treatment‐naïve advanced HCC. The primary objective was safety and tolerability. The secondary objective was clinical efficacy.ResultsA total of 17 patients were treated with three different doses of trametinib and sorafenib. Two patients experienced dose‐limiting toxicity, including grade 4 hypertension and grade 3 elevation of aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/bilirubin over 7 days. Maximum tolerated dose was trametinib 1.5 mg daily and sorafenib 200 mg twice a day. The most common grade 3/4 treatment‐related adverse events were elevated AST (37%) and hypertension (24%). Among 11 evaluable patients, 7 (63.6%) had stable disease with no objective response. The median progression‐free survival (PFS) and overall survival (OS) were 3.7 and 7.8 months, respectively. Phosphorylated‐ERK was evaluated as a pharmacodynamic marker, and sorafenib plus trametinib inhibited phosphorylated‐ERK up to 98.1% (median: 81.2%) in peripheral blood mononuclear cells.ConclusionTrametinib and sorafenib can be safely administered up to trametinib 1.5 mg daily and sorafenib 200 mg twice a day with limited anticancer activity in advanced HCC.  相似文献   
2.
3.
4.
Purpose: Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I–III) was studied.

Materials and methods: Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score?≤??2.0. In addition, we focused on Z-score?≤??1.0 because this may indicate a tendency towards low bone mineral density.

Results: We included 16 studies, comprising 465 patients aged 1–65?years. Moderate and conflicting evidence for low bone mineral density (Z-score?≤??2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score?≤??1.0) for several body parts.

Conclusions: Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy.

  • Implications for Rehabilitation
  • Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP.

  • Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view.

  • If indicated, medication and fall prevention training should be prescribed.

  相似文献   
5.

Background  

The prevalence of tobacco usage in Native American adults and adolescents is higher than any other racial or ethnic group, yet biological risk and protective factors underlying tobacco use in this ethnic group remain unknown. A genome scan for loci associated with tobacco use phenotypes was performed with data collected from a community sample of Mission Indians residing in Southwest California.  相似文献   
6.
7.
8.
9.
BACKGROUND: The HOXA1 gene plays a major role in brainstem and cranial morphogenesis. The G allele of the HOXA1 A218G polymorphism has been previously found associated with autism. METHODS: We performed case-control and family-based association analyses, contrasting 127 autistic patients with 174 ethnically matched controls, and assessing for allelic transmission disequilibrium in 189 complete trios. RESULTS: A, and not G, alleles were associated with autism using both case-control (chi(2) = 8.96 and 5.71, 1 df, p <.005 and <.025 for genotypes and alleles, respectively), and family-based (transmission/disequilibrium test chi(2) = 8.80, 1 df, p <.005) association analyses. The head circumference of 31 patients carrying one or two copies of the G allele displayed significantly larger median values (95.0th vs. 82.5th percentile, p <.05) and dramatically reduced interindividual variability (p <.0001), compared with 166 patients carrying the A/A genotype. CONCLUSIONS: The HOXA1 A218G polymorphism explains approximately 5% of the variance in the head circumference of autistic patients and represents to our knowledge the first known gene variant providing sizable contributions to cranial morphology. The disease specificity of this finding is currently being investigated. Nonreplications in genetic linkage/association studies could partly stem from the dyshomogeneous distribution of an endophenotype morphologically defined by cranial circumference.  相似文献   
10.
There are significant international differences in the type of vascular accesses that are routinely used in the hemodialysis population. Most U.S. hemodialysis patients dialyze with grafts or catheters, while most European and Japanese patients dialyze with the preferable native arteriovenous (A-V) fistulae. Recent analyses suggest that several practice patterns that can be significantly affected by nephrology nurses may help increase both the use of native A-V fistulae and vascular access longevity in the U.S.  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