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   221826篇
  免费   5896篇
  国内免费   584篇
耳鼻咽喉   2996篇
儿科学   7818篇
妇产科学   6122篇
基础医学   29292篇
口腔科学   6638篇
临床医学   17847篇
内科学   41614篇
皮肤病学   4936篇
神经病学   14786篇
特种医学   12308篇
外国民族医学   97篇
外科学   32906篇
综合类   1244篇
一般理论   12篇
预防医学   17308篇
眼科学   4839篇
药学   14983篇
  2篇
中国医学   191篇
肿瘤学   12367篇
  2021年   889篇
  2018年   4206篇
  2017年   4398篇
  2016年   3959篇
  2015年   5701篇
  2014年   5373篇
  2013年   4729篇
  2012年   11988篇
  2011年   6946篇
  2010年   3535篇
  2009年   5026篇
  2008年   4066篇
  2007年   4778篇
  2006年   4965篇
  2005年   12900篇
  2004年   14104篇
  2003年   9654篇
  2002年   4801篇
  2001年   4568篇
  2000年   1859篇
  1999年   6092篇
  1998年   810篇
  1992年   6916篇
  1991年   7150篇
  1990年   7382篇
  1989年   7000篇
  1988年   6502篇
  1987年   6267篇
  1986年   5988篇
  1985年   5270篇
  1984年   3616篇
  1983年   2943篇
  1982年   1035篇
  1981年   792篇
  1980年   859篇
  1979年   3836篇
  1978年   2375篇
  1977年   1801篇
  1976年   1577篇
  1975年   2495篇
  1974年   3124篇
  1973年   2750篇
  1972年   2768篇
  1971年   2752篇
  1970年   2562篇
  1969年   2468篇
  1968年   2237篇
  1967年   2169篇
  1966年   1904篇
  1965年   1135篇
排序方式: 共有10000条查询结果,搜索用时 531 毫秒
951.
952.
Misuse of zopiclone and convulsions during withdrawal.   总被引:3,自引:0,他引:3  
It has been documented that benzodiazepines have the potential to cause dependence and withdrawal reactions, including convulsions. However, the available data concerning zopiclone, a nonbenzodiazepine hypnotic, are insufficient. The present study describes the case of a 36-year-old man who repeatedly misused zopiclone, in daily doses of 60-90 mg. Furthermore, the patient suffered from convulsion on two occasions following abrupt withdrawal of zopiclone. The concomitant use of alcohol, trimipramine, and promazine may have contributed to the development of convulsions. It is concluded that zopiclone may cause problems associated with misuse and withdrawal reactions similar to those of benzodiazepines.  相似文献   
953.
The effect of insulin on the development of excitotoxic vulnerability in primary cultures of the rat cerebral cortex was examined. Cells were maintained for two weeks in serum-supplemented culture media, in the presence or absence of increasing insulin concentrations. Excitotoxic cell death was induced by 1 mM glutamate. The vulnerability of cells was evaluated by phase contrast microscopy and by the measurement of lactate dehydrogenase (LDH) release due to cytotoxic injury. In addition to a moderate (less than 50%) stimulation of protein and DNA synthesis, insulin produced more than a twofold increase in the excitotoxic vulnerability of cells. The effect of insulin was specific, concentration-dependent and required an intact molecular structure of insulin. Our findings indicate that insulin induces significant changes in cerebral neurons by increasing the lethal vulnerability of cortical cells to excitatory amino acids (EAAs).  相似文献   
954.
Biochemical results concerning 64 patients suspected of mitochondrial myopathies are presented. Four clinical groups were studied including 21 encephalomyopathies, 42 ocular myopathies, 8 isolated myopathies and 3 cardiomyopathies. In 26 cases, the coexistence of a normal mitochondrial DNA and a mutated mitochondrial DNA (heteroplasmy) was found (19 simple deletions, 4 multiple deletions and 3 punctual mutations) and all cases presented with ocular disorders (excepted 2 cases with MERRF). Furthermore, 1 complex I deficiency (1 ocular myopathy), 1 complex IV deficiency (1 adult encephalomyopathy type Leigh), 3 complexes I + IV deficiencies (2 cases with a cardiomyopathy and 1 familial MELAS) and 2 pyruvate (1 adult from of Leigh's encephalomyopathy) dehydrogenase deficiencies (clinically and genetically different) did not show evidence of mitochondrial DNA mutation.  相似文献   
955.
956.
957.
We describe an unusual case of absolute bilateral phakolytic glaucoma. On admission for cataract surgery the 75-year-old patient was found to be totally blind, no light perception in either eye. The ocular tensions were about 75 mmHg in both eyes, corneas hazy, the fundi could not be seen. The swollen lens of the right eye had slightly subluxated downwards. In the left eye the ultrasound showed a luxated swollen lens in the vitreous space. The ultrasound also revealed totally excavated optic discs. This patient had been on the waiting list for 8 months. Information of the stage of the cataracts of patients on the waiting lists for operation is of paramount importance in the prevention of lens induced problems which may lead to irreversible visual deterioration.  相似文献   
958.
The study is based on the work histories and mortality data for 3832 male workers first employed before 1967 at a copper smelter in northern Sweden and followed up from 1950 to 1981. From the 3832 workers a lead cohort consisting of 437 workers employed for at least three years at sites with considerable lead exposure during 1950-74 was selected. These workers had regularly had blood lead measurements performed since 1950. Based on the cumulative blood lead dose 1950-74 and peak blood lead values, the cohort was subdivided into high mean, low mean, high peak, and low peak groups. Standardised mortality ratios (SMR) were calculated for the six groups using general and local reference populations. The original cohort of 3832 workers showed considerable excess of deaths for total mortality, malignant neoplasms especially lung and stomach cancer, ischaemic heart diseases, and cerebrovascular diseases when compared with the general population. In the lead cohort where the workers had been subjected to a considerable lead exposure only the raised SMR for lung cancer was sustained (SMR = 162; not significant). No significant differences were found between high lead and low lead exposed smelter workers.  相似文献   
959.
A case, referred to the Department of Stomatognathic Physiology, G?teborg, with an unstable occlusion is presented. There was a facial asymmetry and the bony morphology differed markedly between the sides. No EMG activity in the masticatory muscles could be detected on the left side. It was diagnosed as a probable sequela to poliomyelitis in the childhood. The impact of altered muscle function on the bony structures and dentition is discussed.  相似文献   
960.
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