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   126421篇
  免费   10739篇
  国内免费   8185篇
耳鼻咽喉   1024篇
儿科学   1562篇
妇产科学   2324篇
基础医学   14833篇
口腔科学   2067篇
临床医学   16441篇
内科学   20689篇
皮肤病学   1450篇
神经病学   6889篇
特种医学   4302篇
外国民族医学   70篇
外科学   13109篇
综合类   18988篇
现状与发展   24篇
一般理论   5篇
预防医学   7818篇
眼科学   3652篇
药学   12838篇
  116篇
中国医学   6081篇
肿瘤学   11063篇
  2024年   353篇
  2023年   1849篇
  2022年   4705篇
  2021年   5926篇
  2020年   4259篇
  2019年   4081篇
  2018年   4142篇
  2017年   3706篇
  2016年   3472篇
  2015年   5240篇
  2014年   6550篇
  2013年   6110篇
  2012年   8919篇
  2011年   9771篇
  2010年   5953篇
  2009年   4738篇
  2008年   6510篇
  2007年   6497篇
  2006年   6544篇
  2005年   6479篇
  2004年   4459篇
  2003年   4212篇
  2002年   3560篇
  2001年   3223篇
  2000年   3311篇
  1999年   3448篇
  1998年   2243篇
  1997年   2168篇
  1996年   1564篇
  1995年   1457篇
  1994年   1266篇
  1993年   819篇
  1992年   1227篇
  1991年   1075篇
  1990年   931篇
  1989年   823篇
  1988年   712篇
  1987年   668篇
  1986年   508篇
  1985年   463篇
  1984年   249篇
  1983年   178篇
  1982年   118篇
  1981年   116篇
  1980年   76篇
  1979年   120篇
  1978年   59篇
  1976年   52篇
  1975年   55篇
  1974年   65篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
BACKGROUNDGuillain-Barré syndrome (GBS) is a rare disorder that typically presents with ascending weakness, pain, paraesthesias, and numbness, which mimic the findings in lumbar spinal stenosis. Here, we report a case of severe lumbar spinal stenosis combined with GBS.CASE SUMMARYA 70-year-old man with a history of lumbar spinal stenosis presented to our emergency department with severe lower back pain and lower extremity numbness. Magnetic resonance imaging confirmed the diagnosis of severe lumbar spinal stenosis. However, his symptoms did not improve postoperatively and he developed dysphagia and upper extremity numbness. An electromyogram was performed. Based on his symptoms, physical examination, and electromyogram, he was diagnosed with GBS. After 5 d of intravenous immunoglobulin (0.4 g/kg/d for 5 d) therapy, he gained 4/5 of strength in his upper and lower extremities and denied paraesthesias. He had regained 5/5 of strength in his extremities when he was discharged and had no symptoms during follow-up.CONCLUSIONGBS should be considered in the differential diagnosis of spinal disorder, even though magnetic resonance imaging shows severe lumbar spinal stenosis. This case highlights the importance of a careful diagnosis when a patient has a history of a disease and comes to the hospital with the same or similar symptoms.  相似文献   
3.
4.
5.
6.
7.
8.
评估玻璃体切割联合内界膜剥除对糖尿病性黄斑水肿(DME)的疗效。方法:回顾性病例对照研究。2014年6月至2017年1月间因糖尿病视网膜病变合并玻璃体积血或增殖病变于温州医科大学附属眼视光医院杭州院区行玻璃体切割手术治疗,且术前或术中经光学相干断层扫描(OCT)检查确诊合并DME的患者31例(33眼)纳入研究。16例(18眼)术中联合内界膜剥除作为剥膜组,15例(15眼)仅接受玻璃体切割手术治疗者作为对照组。所有手术均由同一医师主刀完成。术后1、3个月随访时复查OCT,对比观察黄斑中心厚度(CMT)和视力的术后变化情况。随访中CMT和最佳矫正视力(BCVA)比较采用重复测量方差分析,组间CMT和BCVA比较采用独立样本t检验。结果:手术前,手术后1、3个月2组间比较LogMAR视力总体差异有统计学意义(F=15.93,P<0.001)。术后 1个月时剥膜组BCVA高于对照组(t=2.55,P=0.02),但术后3个月时2组间差异无统计学意义(t=0.82, P=0.42)。手术前,手术后1、3个月CMT总体差异无统计学意义(F=2.85,P=0.065)。术后1、3个月时,剥膜组的CMT均低于对照组,2组间差异均有统计学意义(t=2.24,P=0.03;t=3.79,P=0.001)。术后1个月时,剥膜组有效(与术前比CMT减少20%以上)、无效(变化不超过20%)及恶化(增厚超过 20%)的例数分别为8、6、4例,术后3个月时则分别为11、5、2例,与对照组相比,术后1个月时组间差异无统计学意义(Z=-1.687,P=0.092),术后3个月时剥膜组DME改善有效比例明显高于对照组,组间差异有统计学意义(Z=-2.177,P=0.029)。结论:对于非牵拉性DME,内界膜剥除有助于术后早期DME消退。  相似文献   
9.

Background

Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.

Objectives

To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.

Methods

Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.

Results

Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.

Conclusions

These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study.  相似文献   
10.
Two new bisamides, aglaiamides A (1) and B (2), along with three known ones (35), were isolated from the leaves of Aglaia perviridis. Their structures were established on the basis of detailed spectroscopic analyses.  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