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   72618篇
  免费   7598篇
  国内免费   4791篇
耳鼻咽喉   478篇
儿科学   1193篇
妇产科学   706篇
基础医学   5874篇
口腔科学   1372篇
临床医学   9565篇
内科学   8384篇
皮肤病学   753篇
神经病学   2604篇
特种医学   2456篇
外国民族医学   19篇
外科学   5148篇
综合类   17239篇
现状与发展   21篇
一般理论   5篇
预防医学   7853篇
眼科学   1458篇
药学   8644篇
  94篇
中国医学   6975篇
肿瘤学   4166篇
  2024年   326篇
  2023年   981篇
  2022年   2367篇
  2021年   3128篇
  2020年   2764篇
  2019年   1820篇
  2018年   1812篇
  2017年   2209篇
  2016年   1806篇
  2015年   2970篇
  2014年   3869篇
  2013年   4502篇
  2012年   6468篇
  2011年   6877篇
  2010年   5699篇
  2009年   4824篇
  2008年   5069篇
  2007年   4924篇
  2006年   4504篇
  2005年   3866篇
  2004年   2613篇
  2003年   2380篇
  2002年   2080篇
  2001年   1663篇
  2000年   1385篇
  1999年   807篇
  1998年   420篇
  1997年   389篇
  1996年   310篇
  1995年   283篇
  1994年   236篇
  1993年   124篇
  1992年   179篇
  1991年   182篇
  1990年   149篇
  1989年   139篇
  1988年   114篇
  1987年   126篇
  1986年   103篇
  1985年   80篇
  1984年   60篇
  1983年   54篇
  1982年   31篇
  1981年   30篇
  1980年   34篇
  1979年   25篇
  1978年   25篇
  1973年   29篇
  1972年   23篇
  1970年   17篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
61.
香烟烟雾提取物致小鼠生殖细胞的遗传学损伤   总被引:5,自引:1,他引:4  
目的:研究香烟烟雾提取物对小鼠生殖细胞染色体和精子的影响,方法:给雄性小鼠腹腔注射不同剂量的香烟烟雾提取物,观察其精原细胞染色体畸变及精子畸形的情况,结果:精原细胞染色体畸变率及精子畸形率均增高,精子畸形率增高的程度大于精原细胞染色体畸变率。结论:香烟烟雾提取物可致雄性小鼠生殖细胞染色体畸变和精子畸形。  相似文献   
62.
From July 1 994to June 1 999,5 4 5 onychomyco-sis patients were treated with Itraconazole and com-pleted their treatment courses with complete follow-up in out- patientdepartment.The recovery rate was83.1 4% and 79.2 3% in fingernail and toenail dis-eases respectively.But following phenomena werefound:( 1 ) Some new nails stopped growing in cer-tain length,even if the treatment continued;( 2 )Some damaged nails reappeared soon after the treat-ment ceased;( 3) Some damaged nails with deep- co…  相似文献   
63.
Tang  Xin  Chen  Lixin  Chen  Wenwen  Li  Peiyun  Zhang  Ling  Fu  Ping 《International urology and nephrology》2021,53(9):1911-1921
Purpose

Intradialytic hypotension (IDH) is a serious complication in dialysis patients. Diuretics might reduce the incidence of IDH by decreasing ultrafiltration. However, the effect of diuretics on IDH in maintenance dialysis patients is still unclear.

Methods

We searched Medline, Embase, the Cochrane Library, China National Knowledge Infrastructure and clinical trials registries from 1945 to May 2019. Randomized controlled trials (RCTs) or observational studies about IDH in maintenance dialysis with diuretics were included.

Results

Seven studies including 28,226 patients were included, of which 4 were RCTs involving mineralocorticoid receptor antagonists (MRAs) and 3 were observational studies involving loop diuretics. There was a trend that a lower incidence rate of IDH in maintenance dialysis patients who used loop diuretics than control, although the result was not statistically significant (OR 0.65, 95% CI 0.34–1.22, P?=?0.18). Similarly, lower incidence rate of all-cause mortality (OR 0.92, 95% CI 0.87–0.99; P?=?0.02) and cardiovascular (CV) mortality (OR 0.86, 95% CI 0.75–0.99, P?=?0.03) in dialysis patients who used loop diuretics than control. On the contrary, there were no significant difference in the incidence of IDH (OR 1.35, 95% CI 0.78–2.34, P?=?0.29) and all-cause mortality (OR 0.73, 95% CI 0.26–2.01; P?=?0.54) and CV mortality (OR 0.57, 95% CI 0.14–2.25; P?=?0.42) in maintenance dialysis patients who used MRAs compared with control.

Conclusion

Loop diuretics, but not MRAs, might have a potential benefit to reduce the incidence rate of IDH, all-cause mortality and CV mortality. More high-quality studies are needed to strengthen the arguments.

  相似文献   
64.
Dai  Wei  Zhuang  Zong  Ling  Haiping  Yang  Yongbo  Hang  Chunhua 《Neurosurgical review》2021,44(1):515-527
Neurosurgical Review - To quantitatively synthesize the comparative efficacy and safety of the most common surgical approaches including endonasal transsphenoidal endoscopic surgery (ETES),...  相似文献   
65.
Tea is a famous beverage that is produced from leaves of Camellia sinensis. Amongst the six major tea categories in China, dark tea is the only one that involves microbial fermentation in the manufacturing process, which contributes unique flavors and functions for the tea. In the recent decade, the reports about the biofunctions of dark teas have increased rapidly. Therefore it may be the proper time to consider dark tea as one potential homology of medicine and food. In this viewpoint, our current understanding of the chemical constituents, biological activities and possible health beneficial effects of dark teas were introduced. Some future directions and challenges to the development perspectives of dark teas were also discussed.  相似文献   
66.
67.
Rhabdomyosarcoma (RMS) is a common malignancy in children, but embryonal rhabdomyosarcoma (ERMS) deposits rarely occur in the breast in adults. Therefore, little is known about magnetic resonance imaging (MRI) features of breast metastases from RMS, especially the embryonal type. We reported a case of a 22-year-old woman who was diagnosed with ERMS at left foot 2 years ago and accepted operation and chemotherapy. She was confirmed to have breast metastases from the left foot. Successive imaging examinations were performed 3 months apart. Breast ultrasound indicated a benign lesion, and further examination did not reveal any bone metastases. However, predominant restricted diffusion and rim contrast enhancement on MRI combined with the patient's medical history suggested a malignancy of BI-RADS 5. After 3 months, breast ultrasound revealed masses detected last time became larger and lobulated. In addition, internal heterogeneous intensity and rim contrast enhancement with restricted diffusion were revealed on MRI. We speculated that typical MRI findings of breast metastases from RMS may include iso- to hypointensity on T1WI, heterogeneous hyperintensity on T2WI, and circular enhancement with restricted diffusion. Moreover, mild peritumoral edema, rapid expansion of necrosis, and ascending time-intensity curve detected on MRI may be features of the ERMS type.  相似文献   
68.
69.
慢性肺源性心脏病人血液触变特性   总被引:1,自引:0,他引:1  
本文用Low Shear 30流变测定仪,测定了55例肺心病患者全血触变特性的变化,分析了这些变化与肺心病发生和发展的关系。结果表明:肺心病患者血液的触变特性发生了异常改变。HCT、τ_o、η_s、μ、(η_s-μ)、A、ARC均升高,并随病情加重而逐渐明显。其原因主要在于肺心病缺氧所致的继发性红细胞增多及血液氧分压降低,和二氧化碳分压升高所致的红细胞变形性降低。血液触交特性的改变又使血液循环外周阻力增大,右心负荷增加,从而进一步加重了病情的发展。  相似文献   
70.
豚鼠灌服地高辛复制地高辛中毒模型,研究五加对地高辛中毒的影响。结果发现,服刺五加组豚鼠发生心律失常较未给药组明显推迟,而血中地高辛浓度则显著高于未给药组,提未临床应用地高辛时同时给予刺五加有于减少减轻地高辛的毒性反应。  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