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   1640301篇
  免费   113545篇
  国内免费   2556篇
耳鼻咽喉   22712篇
儿科学   53317篇
妇产科学   43175篇
基础医学   242859篇
口腔科学   46101篇
临床医学   147911篇
内科学   309032篇
皮肤病学   37438篇
神经病学   121639篇
特种医学   63269篇
外国民族医学   276篇
外科学   246557篇
综合类   33859篇
现状与发展   3篇
一般理论   404篇
预防医学   117928篇
眼科学   38338篇
药学   129270篇
  10篇
中国医学   4709篇
肿瘤学   97595篇
  2019年   12231篇
  2018年   17622篇
  2017年   13781篇
  2016年   15495篇
  2015年   17277篇
  2014年   23590篇
  2013年   34931篇
  2012年   47284篇
  2011年   49916篇
  2010年   29351篇
  2009年   27634篇
  2008年   46214篇
  2007年   49586篇
  2006年   50454篇
  2005年   47625篇
  2004年   45980篇
  2003年   44054篇
  2002年   42633篇
  2001年   86424篇
  2000年   88320篇
  1999年   73423篇
  1998年   18767篇
  1997年   16320篇
  1996年   16516篇
  1995年   15627篇
  1994年   14183篇
  1993年   13361篇
  1992年   55330篇
  1991年   54050篇
  1990年   52988篇
  1989年   51410篇
  1988年   46515篇
  1987年   45268篇
  1986年   42861篇
  1985年   40211篇
  1984年   29371篇
  1983年   24846篇
  1982年   13762篇
  1979年   26563篇
  1978年   18242篇
  1977年   15951篇
  1976年   14402篇
  1975年   16281篇
  1974年   18970篇
  1973年   18289篇
  1972年   17382篇
  1971年   16272篇
  1970年   15234篇
  1969年   14443篇
  1968年   12971篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
31.
32.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
33.

Purpose

Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.

Methods

Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.

Results

CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.

Conclusion

PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.  相似文献   
34.
Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.  相似文献   

35.
36.
Bulletin of Experimental Biology and Medicine - Ammonium, an end-product of catabolism, in low doses can promote adaptation of metabolic pathways in erythrocytes under conditions of extreme...  相似文献   
37.
38.
39.
40.
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