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   49127篇
  免费   3217篇
  国内免费   73篇
耳鼻咽喉   438篇
儿科学   1368篇
妇产科学   1066篇
基础医学   7285篇
口腔科学   1708篇
临床医学   4281篇
内科学   10571篇
皮肤病学   842篇
神经病学   4693篇
特种医学   1868篇
外国民族医学   11篇
外科学   6542篇
综合类   183篇
现状与发展   1篇
一般理论   64篇
预防医学   4832篇
眼科学   723篇
药学   2537篇
中国医学   47篇
肿瘤学   3357篇
  2023年   199篇
  2022年   355篇
  2021年   674篇
  2020年   518篇
  2019年   769篇
  2018年   908篇
  2017年   788篇
  2016年   949篇
  2015年   1013篇
  2014年   1351篇
  2013年   1773篇
  2012年   2742篇
  2011年   2732篇
  2010年   1512篇
  2009年   1567篇
  2008年   2428篇
  2007年   2532篇
  2006年   2485篇
  2005年   2350篇
  2004年   2057篇
  2003年   1991篇
  2002年   1695篇
  2001年   1672篇
  2000年   1597篇
  1999年   1491篇
  1998年   591篇
  1997年   549篇
  1996年   542篇
  1995年   425篇
  1994年   409篇
  1993年   398篇
  1992年   1068篇
  1991年   996篇
  1990年   972篇
  1989年   893篇
  1988年   842篇
  1987年   724篇
  1986年   729篇
  1985年   649篇
  1984年   454篇
  1983年   372篇
  1982年   196篇
  1981年   194篇
  1979年   324篇
  1977年   177篇
  1975年   194篇
  1974年   191篇
  1973年   195篇
  1972年   222篇
  1971年   188篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Following injections of 3H-leucine and 35S-methionine in the caudal half of the medial accessory olive, labeled climbing fibers were found contralateral to the injection site in the sagittal A-zone of the cerebellar vermis and in the fastigial nucleus. Labeling in the fastigial nucleus was analyzed with ultrastructural autoradiography. Labeled boutons of climbing fibers were found in the neuropil but never on somata. They contain spherical vesicles and occasionally some dense core vesicles in an electron-lucent matrix. The terminals of climbing fiber collaterals in the fastigial nucleus resemble climbing fiber terminals in the molecular layer with respect to their internal ultrastructural characteristics.  相似文献   
92.
93.
Out of 29 patients with right-sided infective endocarditis 13 had associated congenital heart disease and none was a drug addict. Staphylococcus aureus was the commonest organism isolated. The tricuspid valve was infected twice as commonly as the pulmonary valve. Only 11 out of the 29 patients had valvular infection potentially amenable to surgical therapy at the time of death. Ring abscesses were present in 10 patients.  相似文献   
94.
95.
We describe a 53-year-old women with eosinophilia-myalgia syndrome who suddenly developed severe persistent myalgias of her arms, legs, back, and shoulder after a 5-month period of daily L-tryptophan ingestion, associated with fever, progressive stenocardia and left-sided congestive heart failure. Laboratory tests showed a leukocytosis of 11.2/nl with 3.14/nl eosinophils and an elevated erythrocyte sedimentation rate. There was a marked, predominantly proximal sclerosis of her arms, legs and trunk with a brownish discoloration. The skin of her arms and legs appeared dimpled (peau d'orange). Findings of the electrophysiological examinations were consistent with sensory neuropathy and myositis. Remarkable fasciitis and interstitial myositis were present in a biopsy specimen (from skin to muscle) taken from her thigh. However, eosinophilic infiltrates were rare. Angiography revealed an apical obstructive cardiomyopathy. In this paper, we describe the clinical findings, the course over 2 years, as well as the therapeutic management. Furthermore, the most important differential diagnoses are discussed and the literature is reviewed with special attention given to more recent pathogenic insights into this newly recognized multisystem disease.  相似文献   
96.
If a patternless field is modulated sinusoidally in time so that the luminance change in one eye is in counterphase to that in the other, the resulting flicker appears faster than if the modulation to both eyes has the same phase. If observers set the frequency and the amplitude of a comparison in-phase field so that it matches a neighbouring counterphase field, modulated at, say, 2.5 x its threshold, they set the frequency to twice the counterphase frequency, and the amplitude to a value that is, for a given frequency, a constant ratio of the modulation of the counterphase field. Counterphase stimulation thus appears to cause an internal second-harmonic signal. However, it is not possible to cancel this by adding a second harmonic component to the stimulus.  相似文献   
97.
98.
99.
The per- and post-operative characteristics of three different i.v. anaesthetic induction agents were studied double-blindly in 75 patients admitted for outpatient gynaecological dilatation and curettage. All the patients were premedicated with midazolam 0.1 mg/kg i.m. Induction started with alfentanil 0.015 mg/kg i.v. 60 s before either: propofol 2.2 mg/kg i.v., or thiopentone 4.0 mg/kg i.v., or methohexitone 2.0 mg/kg i.v. All the patients received 66% nitrous oxide in oxygen. The propofol patients were significantly better relaxed and had a higher incidence of hypotension during the procedure. The methohexitone patients had higher pulse rates and a higher frequency of hiccups during the procedure. Propofol induction resulted in a faster awakening of the patients and a better recovery function compared with methohexitone for the first 15 min and compared with thiopentone for the first 240 min after the procedure. Postoperative side-effects were less frequent in the thiopentone group, and minor abdominal pain was significantly more frequent in the propofol group. There was no significant difference between the groups for any variable after 240 min postoperatively.  相似文献   
100.
This study was initiated in 1986 in response to increased interest in restorative procedures favoring preservation of tooth substance and in the search for alternatives to dental amalgams. Eighty-seven preventive resin restorations in permanent molars and 35 occlusal composite resin restorations in primary molars (limited size) and 13 in premolars were followed up for 2 years. They were placed by a large number of operators, mainly dental students under supervision, and rated by five calibrated instructors in accordance with an internationally accepted system for the evaluation of the clinical performance of dental materials. One composite resin (Occlusin) was used. A survival model was used to calculate the cumulative theoretical number of successful treatments of children who had dropped out. For none of the 6 clinical variables was the success rate lower than 91%, and only 3 of 26 failures were of a nature requiring remake or correction. The failures occurred, with a few exceptions, during the 1st year of observation. The two types of restoration have thus proved to be efficient treatments fulfilling all reasonable requirements in modern operative dentistry.  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