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   79685篇
  免费   7513篇
  国内免费   4728篇
耳鼻咽喉   817篇
儿科学   1201篇
妇产科学   966篇
基础医学   8374篇
口腔科学   1380篇
临床医学   8728篇
内科学   11530篇
皮肤病学   1267篇
神经病学   4393篇
特种医学   2939篇
外国民族医学   27篇
外科学   9444篇
综合类   14411篇
现状与发展   16篇
一般理论   19篇
预防医学   5813篇
眼科学   2055篇
药学   7750篇
  70篇
中国医学   4758篇
肿瘤学   5968篇
  2024年   216篇
  2023年   997篇
  2022年   2241篇
  2021年   3209篇
  2020年   2614篇
  2019年   2263篇
  2018年   2460篇
  2017年   2435篇
  2016年   2321篇
  2015年   3246篇
  2014年   4060篇
  2013年   4266篇
  2012年   6122篇
  2011年   6627篇
  2010年   4735篇
  2009年   4096篇
  2008年   4922篇
  2007年   4813篇
  2006年   4578篇
  2005年   4140篇
  2004年   3360篇
  2003年   3175篇
  2002年   2817篇
  2001年   2094篇
  2000年   1760篇
  1999年   1407篇
  1998年   830篇
  1997年   731篇
  1996年   560篇
  1995年   542篇
  1994年   458篇
  1993年   309篇
  1992年   403篇
  1991年   412篇
  1990年   355篇
  1989年   316篇
  1988年   273篇
  1987年   242篇
  1986年   235篇
  1985年   187篇
  1984年   131篇
  1983年   82篇
  1982年   57篇
  1981年   58篇
  1979年   78篇
  1977年   59篇
  1976年   56篇
  1974年   73篇
  1973年   60篇
  1972年   63篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Bilateral horizontal gaze palsies are rare. In this case report, we present a 28-year-old woman with bilateral horizontal gaze palsies due to involvement of both paramedian pontine reticular formations (PPRFs) by multiple sclerosis (MS) plaques.  相似文献   
53.
The effects of 3,6-dimethamidodibenzopyriodonium citrate (I-65) on the contractile response of electrically paced guinea pig papillary muscles in vitro were studied. I-65 (0.1-300 mumol/L) decreased the contractile force and inhibited isoprenaline-induced restoration of the contractile response in papillary muscles rendered inexcitable by KCl 22 mmol/L. Both effects were concentration-dependent, and the IC50 were 36.0 and 7.3 mumol/L, respectively. I-65 antagonized the positive inotropic effects of Iso and CaCl2 in a non-competitive manner. Like verapamil, I-65 had a frequency-dependent negative inotropic effect, and delayed the recovery of post-rest potentiation. It is concluded that the negative inotropic effect of I-65 results not only from the reduction of Ca2+-influx through the sarcolemmal membrane, but also from the inhibition of Ca2+ translocation in the sarcoplasmic reticulum.  相似文献   
54.
目的探讨前列腺素E1(PGE1)应用于尸体肾移植术后肾功能延迟恢复(DGF)患者对移植肾功能恢复的影响.方法回顾性分析因急性排斥(AR)和急性肾小管坏死(ANT)导致DGF的127例临床资料,其中应用PGE1治疗56例(PGE1组),未用PGE1者71例(对照组).比较两组在出现DGF后的透析治疗时间、肾功能恢复情况、彩超的移植肾血流阻力指数(RI)及6个月内AR发生率.结果与对照组比较,PGE1组透析治疗时间明显缩短(P<0.05),移植肾的血肌酐下降速度快(P<0.05),RI及6个月内AR发生率低(P<0.05).结论PGE1有利于尸体肾移植术后DGF患者移植肾功能的早期恢复,并能降低AR的发生率.  相似文献   
55.
谈耳鼻喉科教学中多媒体技术的应用   总被引:3,自引:0,他引:3  
多媒体教学技术应用于耳鼻喉科教学,具有直观性好、动态感强、信息量大等优点,能使教学信息直接、形象、具体、生动地展现给学生,让学生体会到学习的乐趣,是耳鼻喉科现代化教学的理想模式.  相似文献   
56.
本文报道对59例健康吸烟者血液流变学9项指标的观察,并与非吸烟组进行比较。吸烟组的血小板粘附率、红细胞压积和全血粘度均较非吸烟组升高,差异非常显著(P<0.001)血浆比粘度在大量吸烟组升高,差异有显著性(P<0.05)说明吸烟使部份血粘滞因素升高,给血液的流变性带来不利影响。不同吸烟量的两组之间各项指标变化无显著差异。本文对发生机制及临床意义略加讨论。  相似文献   
57.
本文报道给家兔注入不同剂量的~3H-α-第二丁基对羟基苄醇,观察该药在其体内的药物动力学。结果表明,血中分布相快,消除相慢,消除半衰期T_1/1β为12h。经F值检验和理论计算值与实测值的契合程度比较,表明该药在兔体内的运转符合二室开放模型的动力学方程。  相似文献   
58.
In view of the ability of ketones to partially replace glucose as an alternative fuel in the brain, the potential protective effects of diet-induced ketosis were examined in male NEDH rats with hypoglycaemia due to a serially transplantable radiation-induced insulinoma. Ketosis was induced by daily oral administration of medium chain triglycerides to normal rats and to insulinoma-bearing rats 1 day after subcutaneous subscapular implantation of tumours fragments. All rats treated with medium chain triglycerides became ketotic within 72 hours, and plasma 3-hydroxybutyrate concentrations remained 5-10 fold elevated at 24 days. Untreated insulinoma-bearing rats became moderately hyperinsuliaemic and hypoglycaemic by 17 days, with the later manifestation of more marked hyperinsulineamia (21.6 +/- 0.8 ng/ml, mean +/- SEM) severe hypoglycaemia (1.5 +/- 0.1 mmol/l) and death by 24-28 (26 +/- 1) days. Induction and maintenance of hyperketonaemia did not affect the development of hyperinsulineamia, hypoglycaemia or the exaggerated fall of plasma glucose produced by an 8 hour fast in these rats. However by day 21, the severity of hypoglycaemia was greater in insulinoma-bearing rats receiving medium chain triglycerides, culminating in accelerated death by 22-25 (23 +/- 1) days and an accompanying 50% decrease in final tumour weight. These results demonstrate that induction of ketosis in the face of marked hyperinsulinaemia did not afford protection against the profound hypoglycaemia produced by a serially transplantable rat insulinoma.  相似文献   
59.
60.
Performance standards for toric soft contact lenses.   总被引:1,自引:0,他引:1  
PURPOSE: To simplify the clinical assessment of toric soft contact lens (TSCL) on-eye behavior by establishing a set of standard clinical evaluation techniques. The likely performance range expected among the TSCL wearing population was determined for a series of lens designs and acceptable performance standards indicated for each variable. METHODS: Four prism-ballast, two peri-ballast and one dynamic stabilization TSCL designs were each worn by groups of 20 subjects in a nondispensing study. After 20 min of lens wear, lenses were assessed, in right eyes only, for subjective comfort (100-point scale), lens mislocation (degrees deviation from vertical) and rotational recovery after deliberate 30 degrees mislocation (degrees/10 blinks). The percentage of lenses orienting within +/-10 degrees of target orientation (zero rotation) and the variability of orientation (standard deviation of mislocation) were also calculated for each lens group. RESULTS: Based on partitioning of the data distributions for each variable, performance was designated as excellent, acceptable or poor. Corresponding performance cut-offs were determined at > or =90, 89 to 80, and <80 for subjective comfort, < or =+/-6 degrees , +/-7 degrees to 10 degrees , and >+/-10 degrees for mislocation, >10 degrees /10 blinks, 10 degrees to 6 degrees /10 blinks, and <6 degrees /10 blinks for rotational recovery. For groups of wearers the appropriate cut-offs were > or =90%, 89 to 70%, and <70% of lenses orienting within +/-10 degrees of target orientation and <+/-6 degrees , +/-6 degrees to 10 degrees , and >+/-10 degrees for variability of orientation. CONCLUSION: Techniques suitable for the evaluation of TSCL clinical performance have been described and guidelines for the assessment of such lenses established. In the process, we have identified potential performance differences that may relate to variations in TSCL design.  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