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   722篇
  免费   63篇
  国内免费   5篇
耳鼻咽喉   2篇
儿科学   37篇
妇产科学   27篇
基础医学   55篇
口腔科学   20篇
临床医学   91篇
内科学   174篇
皮肤病学   15篇
神经病学   25篇
特种医学   96篇
外科学   85篇
综合类   9篇
预防医学   52篇
眼科学   4篇
药学   62篇
  2篇
肿瘤学   34篇
  2023年   7篇
  2022年   6篇
  2021年   7篇
  2020年   9篇
  2019年   10篇
  2018年   18篇
  2017年   14篇
  2016年   21篇
  2015年   23篇
  2014年   29篇
  2013年   31篇
  2012年   25篇
  2011年   22篇
  2010年   27篇
  2009年   35篇
  2008年   34篇
  2007年   15篇
  2006年   30篇
  2005年   18篇
  2004年   22篇
  2003年   15篇
  2002年   22篇
  2001年   20篇
  2000年   16篇
  1999年   17篇
  1998年   23篇
  1997年   21篇
  1996年   19篇
  1995年   17篇
  1994年   16篇
  1993年   15篇
  1992年   5篇
  1991年   10篇
  1990年   11篇
  1989年   14篇
  1988年   13篇
  1987年   12篇
  1986年   12篇
  1985年   15篇
  1984年   7篇
  1983年   9篇
  1982年   7篇
  1980年   4篇
  1979年   12篇
  1978年   7篇
  1977年   5篇
  1976年   7篇
  1975年   6篇
  1969年   5篇
  1966年   12篇
排序方式: 共有790条查询结果,搜索用时 0 毫秒
101.
We instilled naphazoline Hcl (0.1%), an imidazole derivative with preferential alpha-2 activity, in 17 eyes of 12 patients with myopathic ptosis due to involvement of the levator palpebrae superioris, in the attempt to selectively stimulate Müller's smooth muscle. Naphazoline significantly widened the palpebral fissure with little change in pupillary diameter and no significant change in ocular pressure, visual acuity and near point determination. However, a reduction of the effect, probably due to tachyphylaxis, was noticed when using naphazoline regularly several times a day for few weeks. In conclusion naphazoline has powerful cosmetical and functional effects in mild to moderate myopathic ptosis above all if taken occasionally.  相似文献   
102.
103.
Human breast cancer in vivo: H-1 and P-31 MR spectroscopy at 1.5 T   总被引:3,自引:0,他引:3  
To assess the potential of in vivo magnetic resonance (MR) spectroscopy for breast cancer, hydrogen-1 and phosphorus-31 MR spectra of five malignant human breast tumors were compared with those of unaffected breast tissue. The water-to-fat ratio was high in the tumors (average, 2.2) but low in the unaffected tissue (average, 0.3). The P-31 spectrum of normal breast tissue showed low levels of phosphomonoesters (PMEs), inorganic phosphate, phosphodiesters (PDEs), and ATP. In addition, an intense phosphocreatine (PCr) signal was observed in breast tissue of young women: The relative intensities of the PCr and ATP signals had a mean value of 1.9. The tumor spectrum showed elevated levels of PMEs, Pi, and PDEs, while no PCr was seen (PCr/ATP less than 0.2). In two breast cancers treated with radiation therapy, resulting in a decrease of tumor volume of more than 50%, a similar change in the tumor P-31 spectrum was observed: An intense PCr signal developed (PCr/ATP = 1.1). Control experiments indicated that the appearance of PCr after radiation therapy was the result of a radiation-induced metabolic change in the tumor itself.  相似文献   
104.
105.
The effects of a new inhaled antimuscarinic drug, oxitropium bromide, and of a slow-release theophylline preparation upon nocturnal asthma were compared in a placebo-controlled double-blind study. Two samples were studied: 12 patients received oxitropium at 600 micrograms (6 subjects) or at 400 micrograms t.i.d. (6 subjects) whereas 11 received theophylline at 300 mg b.i.d. Morning dipping, assessed by the fall in peak flow overnight, was significantly reduced in the periods when either active drug was taken, whereas no difference was noticed during the placebo administration. No significant difference was noticed between results obtained with either active drug, as well as with either dosage of oxitropium. No subject reported side effects of oxitropium, as compared to three subjects reporting nausea, vomiting and tremors after theophylline. Oxitropium proves to be a valuable alternative to theophylline in nocturnal asthma, since it is equally potent, safer and does not require the titration of dosage.  相似文献   
106.
Non-invasive methods for assessment of the vascular effects of antimigraine drugs were evaluated with respect to their utility, variability and sensitivity in a double-blind, placebo-controlled, three-period crossover study in six healthy volunteers using an intravenous vasoconstrictor, methoxamine, as a probe drug. Changes in the internal diameter of the brachial and radial arteries were measured using ultrasound which had low between-day and within-day coefficients of variation. Peak systolic velocity (PSV), time-averaged velocity (TAV), total flow, resistance (RI) and pulsatility indices (PI) were measured by Doppler from one arterial wave form. Whilst PSV and TAV increased with methoxamine, because of bradycardia, changes in PI and RI were difficult to interpret. An automatic oscillametric cuff, a mercury-in-silastic strain gauge method and the "Finapres", finger arterial blood pressure monitor were used to follow changes in systolic blood pressure (SBP). The strain gauge technique underestimated arm SBP compared to the oscillometric method but clearly showed drug-related increases whilst the Finapres did not reflect changes in blood pressure detected by the other methods.  相似文献   
107.
108.
109.
110.
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