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   9800篇
  免费   724篇
  国内免费   17篇
耳鼻咽喉   158篇
儿科学   421篇
妇产科学   374篇
基础医学   1349篇
口腔科学   463篇
临床医学   970篇
内科学   1586篇
皮肤病学   277篇
神经病学   888篇
特种医学   451篇
外科学   1458篇
综合类   147篇
一般理论   3篇
预防医学   761篇
眼科学   217篇
药学   539篇
中国医学   13篇
肿瘤学   466篇
  2021年   147篇
  2019年   137篇
  2018年   155篇
  2017年   107篇
  2016年   138篇
  2015年   142篇
  2014年   206篇
  2013年   275篇
  2012年   363篇
  2011年   432篇
  2010年   243篇
  2009年   243篇
  2008年   353篇
  2007年   413篇
  2006年   443篇
  2005年   375篇
  2004年   363篇
  2003年   286篇
  2002年   295篇
  2001年   315篇
  2000年   287篇
  1999年   264篇
  1998年   128篇
  1997年   116篇
  1996年   106篇
  1995年   116篇
  1994年   94篇
  1993年   102篇
  1992年   212篇
  1991年   178篇
  1990年   224篇
  1989年   218篇
  1988年   223篇
  1987年   205篇
  1986年   190篇
  1985年   187篇
  1984年   149篇
  1983年   131篇
  1982年   95篇
  1981年   82篇
  1979年   118篇
  1978年   94篇
  1977年   91篇
  1976年   79篇
  1975年   93篇
  1974年   92篇
  1973年   89篇
  1972年   78篇
  1971年   85篇
  1970年   84篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
Deformation due to growth disturbance after epiphyseal fractures around the knee may involve more than the primarily injured epiphysis, as spontaneous corrective growth of the opposite epiphyseal plate can take place in an attempt to maintain overall alignment of the leg. As a result, there will be an inclination in the knee joint line if corrective osteotomy is only performed for the primary angulation. We report two cases of this complex deformity in which corrective osteotomies of both the distal femur and the proximal tibia were performed, resulting in correct alignment of the overall leg axis and knee joint axis. Received: 25 May 1996 Accepted: 20 November 1996  相似文献   
24.
The effect of progesterone on the available intracellular sulphate pool in subcultured glandular epithelial cells from guinea-pig endometrium is reported. Progesterone in concert with 17 beta-estradiol was shown to cause an increase in the available intracellular sulphate pool. The maximum effect was obtained for 10(-8) M and 10(-7) M progesterone. This effect of progesterone on the available intracellular sulphate pool essentially concerned the intracellular inorganic sulphate and was inhibited by the antiprogesterone steroid RU 486 (5 x 10(-7) M). Sulphate incorporation into the endometrial epithelial cells was suppressed by the inhibitor of anion transport diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and the protein synthesis inhibitor, cycloheximide. These results would suggest that a sulphate transport system may be involved in the accumulation of the intracellular sulphate, stimulated by progesterone. This phenomenon could be an early process in the preparation of the endometrium for implantation.  相似文献   
25.
We report on our experience in the use of a new system of a totally implantable device for repeated vascular access in children, developed in 1989 by Pharmacia and named P.A.S. Port (Peripheral Access System Port). The P.A.S. Port is far smaller than other systems and has been designed for peripheral location in the arm. This avoids unsightly pectoral scars particularly in girls and allows insertion under local anesthesia. It is an interesting alternative to the Port-a-Cath for children older than 5 years of age. It is easily accepted by the patient as well as by the caring team.  相似文献   
26.
We report a case of a fatal toxic encephalomyelopathy in a 12-year-old girl due to prophylactic intrathecal injection of methotrexate and cytosine arabinoside, with a characteristic progressive symptomatology leading to death after 28 days. The location and type of neuropathological changes support the hypothesis of a direct toxic effect of methotrexate and/or cytosine arabinoside on structures directly exposed to the cerebrospinal fluid.  相似文献   
27.
The aim of this study was to investigate markers of serotonin and immune function in suicidal patients. Cytotoxic activity of natural killer cells (NK) and CD16 lymphocytes were studied in 28 suicide attempters and 26 healthy controls, and related in patients to 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF). Patients with CSF 5-HIAA below the median had significantly lower NK cell activity than other patients. CD16 cell frequency was significantly lower in patients than in controls, and patients also tended to have lower NK cell cytotoxicity than healthy controls. There were no statistically significant correlations between 4-hydroxy-3methoxyphenyl glycol (HMPG), homovanillic acid (HVA), CSF cortisol and NK cell activity. The results support the hypothesis of compromised immune function in suicidal patients with evidence of disordered serotonin function.  相似文献   
28.
Urine samples from 402 victims of ski accidents were analyzed for the presence of benzodiazepines (BZD) and alcohol. Eighty-one (20%) samples were positive for alcohol; BZD were detected in 34 (8.5%) cases. Ten of the samples (2.5%) were found to be positive for both alcohol and BZD. Subjects who were positive for either alcohol or BZD or both were older than the other persons examined. The prevalence of alcohol was significantly higher among male accident victims. BZD intake could be demonstrated to have a significant influence on the severity of injuries. Besides an increased awareness of the need for skier education regarding drug use, heightened attention of medical caregivers is warranted to inform their patients about potential accident hazards in sport activities when BZD are prescribed.  相似文献   
29.
In this longitudinal study of a random sample of North Carolinians over the age of 65 and living in their homes, 325 blacks and 280 whites were examined and interviewed 18 months after baseline examinations. Coronal caries incidence was greater among whites than blacks. The increment due to teeth becoming root fragments were similar for both races; however, there were more newly crowned teeth among whites. Newly crowned surfaces were not used as part of the caries increment in logistic regression models to investigate potential risk predictors. For blacks, caries development over the 18-month period was associated with a higher lactobacillus score and more coronal caries at baseline, more previously filled coronal surfaces, and lack of active membership in clubs or other groups. For whites, having no self-reported tooth sensitivity, having a lower socioeconomic index score, taking antihistamine medications at baseline, and having the perception of more problems after the age of 40 than before were all associated with the development of coronal caries.  相似文献   
30.
Idiopathic perioptic neuritis is a term used to describe noninfectious inflammatory disorders of the optic nerve sheaths, the causes of which are unknown. In the following report, a 68-year-old woman with bilateral visual loss was found to have chronic inflammation with necrobiotic granulomas of her optic nerve sheaths. The patient, who had no systemic condition known to be associated with necrobiotic granuloma, lost vision from infarction of the optic nerve parenchyma and from compression due to thickened meninges. Although there are similarities between the inflammatory reaction in this case to the necrobiotic dermatoses, the pathogenesis of this condition remains obscure.  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