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   10316篇
  免费   935篇
  国内免费   227篇
耳鼻咽喉   129篇
儿科学   117篇
妇产科学   98篇
基础医学   1535篇
口腔科学   93篇
临床医学   1419篇
内科学   1210篇
皮肤病学   84篇
神经病学   259篇
特种医学   580篇
外国民族医学   4篇
外科学   1571篇
综合类   1446篇
预防医学   299篇
眼科学   114篇
药学   432篇
  3篇
中国医学   1063篇
肿瘤学   1022篇
  2025年   17篇
  2024年   132篇
  2023年   161篇
  2022年   295篇
  2021年   439篇
  2020年   461篇
  2019年   402篇
  2018年   372篇
  2017年   389篇
  2016年   433篇
  2015年   416篇
  2014年   805篇
  2013年   686篇
  2012年   690篇
  2011年   717篇
  2010年   603篇
  2009年   554篇
  2008年   518篇
  2007年   473篇
  2006年   430篇
  2005年   359篇
  2004年   329篇
  2003年   260篇
  2002年   289篇
  2001年   196篇
  2000年   129篇
  1999年   134篇
  1998年   103篇
  1997年   93篇
  1996年   82篇
  1995年   66篇
  1994年   52篇
  1993年   40篇
  1992年   40篇
  1991年   48篇
  1990年   34篇
  1989年   33篇
  1988年   33篇
  1987年   24篇
  1986年   24篇
  1985年   31篇
  1984年   10篇
  1983年   9篇
  1982年   11篇
  1981年   12篇
  1979年   7篇
  1978年   5篇
  1976年   6篇
  1973年   4篇
  1972年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
目的 总结貌似多发性硬化的皮层下梗死和白质脑病的常染色体显性遗传性脑动脉病(CADASIL)的临床特点.方法 报告1例经基因检查和周围神经活检确诊为CADASIL的临床资料.结果 患者腓肠神经活检可见有髓神经纤维密度轻度减少,电镜下可见神经束膜小动脉中层平滑肌细胞外大量颗粒性电子致密嗜锇颗粒物质(GOM)沉积.基因检测显示Notch3基因4号外显子Cys117Arg突变.结论 为避免CADASIL的漏诊及误诊,凡遇青年反复脑卒中发作,又无高血压、糖尿病等常见的血管病危险因素,虽无偏头痛病史,亦应注意追问家族史并做基因检测和周围神经活检.  相似文献   
4.
5.
Two hundred and eight ultrasonographic fine-needle aspiration biopsies were performed in patients with head and neck masses and examined cytologically. The average minimum diameter of the masses was 1.5 cm. The smallest punctured lymph node located in the perivascular sheath had a diameter of 0.4 cm. In none of the patients were complications observed. Ninety-seven percent of the diagnoses based on cytological examination were confirmed in the histological examination of surgical biopsies or in the further clinical course.  相似文献   
6.
7.
Temporal artery biopsy is considered the gold standard investigation of giant cell arteritis and is recommended in suspected cases despite a sensitivity of 81–91%. This review highlights the potential risk of facial nerve injury during temporal artery biopsy and introduces recent advances in the emerging role of imaging modalities. When these non-invasive techniques are used in conjunction with American College of Rheumatology scoring, which includes clinical features and biochemical test results, temporal artery biopsy may be avoided in selected cases.  相似文献   
8.

Background

Prostate biopsy parameters are commonly used to attribute cancer risk. A targeted approach to lesions found on imaging may have an impact on the risk attribution given to a man.

Objective

To evaluate whether, based on computer simulation, targeting of lesions during biopsy results in reclassification of cancer risk when compared with transrectal ultrasound (TRUS) guided biopsy.

Design, setting, and participants

A total of 107 reconstructed three-dimensional models of whole-mount radical prostatectomy specimens were used for computer simulations. Systematic 12-core TRUS biopsy was compared with transperineal targeted biopsies using between one and five cores. All biopsy strategies incorporated operator and needle deflection error. A target was defined as any lesion ≥0.2 ml. A false-positive magnetic resonance imaging identification rate of 34% was applied.

Outcome measurements and statistical analysis

Sensitivity was calculated for the detection of all cancer and clinically significant disease. Cases were designated as high risk based on achieving ≥6 mm cancer length and/or ≥50% positive cores. Statistical significance (p values) was calculated using both a paired Kolmogorov-Smirnov test and the t test.

Results and limitations

When applying a widely used biopsy criteria to designate risk, 12-core TRUS biopsy classified only 24% (20 of 85) of clinically significant cases as high risk, compared with 74% (63 of 85) of cases using 4 targeted cores. The targeted strategy reported a significantly higher proportion of positive cores (44% vs 11%; p < 0.0001) and a significantly greater mean maximum cancer core length (7.8 mm vs 4.3 mm; p < 0.0001) when compared with 12-core TRUS biopsy. Computer simulations may not reflect the sources of errors encountered in clinical practice. To mitigate this we incorporated all known major sources of error to maximise clinical relevance.

Conclusions

Image-targeted biopsy results in an increase in risk attribution if traditional criteria, based on cancer core length and the proportion of positive cores, are applied. Targeted biopsy strategies will require new risk stratification models that account for the increased likelihood of sampling the tumour.  相似文献   
9.
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