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   204890篇
  免费   3427篇
  国内免费   38篇
耳鼻咽喉   1490篇
儿科学   7728篇
妇产科学   3727篇
基础医学   20107篇
口腔科学   2116篇
临床医学   16248篇
内科学   36035篇
皮肤病学   1130篇
神经病学   19302篇
特种医学   9914篇
外科学   32461篇
综合类   2980篇
一般理论   49篇
预防医学   21535篇
眼科学   3255篇
药学   11628篇
  2篇
中国医学   659篇
肿瘤学   17989篇
  2021年   483篇
  2020年   283篇
  2019年   437篇
  2018年   22343篇
  2017年   17650篇
  2016年   19880篇
  2015年   1344篇
  2014年   1466篇
  2013年   1791篇
  2012年   8259篇
  2011年   22449篇
  2010年   19558篇
  2009年   12109篇
  2008年   20728篇
  2007年   23047篇
  2006年   1939篇
  2005年   3439篇
  2004年   4658篇
  2003年   5417篇
  2002年   3503篇
  2001年   1225篇
  2000年   1376篇
  1999年   931篇
  1998年   487篇
  1997年   475篇
  1996年   322篇
  1995年   349篇
  1994年   307篇
  1993年   258篇
  1992年   728篇
  1991年   790篇
  1990年   787篇
  1989年   676篇
  1988年   647篇
  1987年   589篇
  1986年   582篇
  1985年   568篇
  1984年   444篇
  1983年   438篇
  1982年   295篇
  1981年   252篇
  1980年   267篇
  1979年   428篇
  1978年   320篇
  1977年   269篇
  1976年   247篇
  1975年   236篇
  1974年   319篇
  1973年   262篇
  1972年   233篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
41.
42.
This study examined the feasibility of isolating and transferringthe centrosome-containing region of spermatozoa to mature humanoocytes. The findings demonstrate that individual sperm centrosomescan be transferred and are capable of nucleating maternal tubulinto form a well-developed sperm aster in the recipient oocyte.The results are discussed with respect to centrosome functionin early human development and applications in clinical in-vitrofertilization in the treatment of certain forms of male factorinfertility.  相似文献   
43.
44.
Fetal scalp blood sampling (FSBS), in conjunction with fetal heart rate monitoring, is a method of fetal surveillance that may avoid cesarean delivery of the healthy fetus or indicate the need for immediate delivery of a compromised fetus. Some researchers have recently begun to question the efficacy of FSBS. In this article, three nurse-midwives discuss FSBS as a tool in assessing fetal well-being during labor and consider whether FSBS is a nurse-midwifery procedure.  相似文献   
45.
Analysis and management of chronic testicular pain   总被引:3,自引:0,他引:3  
A total of 45 patients was seen in consultation between May 1980 and April 1989 for chronic unilateral or bilateral orchialgia, defined as intermittent or constant testicular pain 3 months or longer in duration that significantly interferes with the daily activities of the patient so as to prompt him to seek medical attention. We analyzed 34 patients available for followup in terms of socioeconomic parameters, etiology and duration of pain, associated urological symptomatology, specific treatment and results of therapy. Of the patients 31 underwent surgical treatment after failing medical management (24 orchiectomies, 10 epididymectomies, 5 orchiopexies and 1 hydrocelectomy). Of 10 patients who underwent epididymectomy 9 underwent subsequent orchiectomy as definitive treatment. Of 15 patients who underwent inguinal orchiectomy 11 (73%) reported complete relief of pain, while 4 had partial relief. Of the 9 patients who underwent scrotal orchiectomy 5 (55%) reported complete relief of pain, 3 had partial relief and 1 denied improvement. On the basis of these results we recommend inguinal orchiectomy as the procedure of choice for the management of chronic testicular pain when conservative measures are unsuccessful.  相似文献   
46.
We performed magnetic resonance imaging on sixty-seven individuals who had never had low-back pain, sciatica, or neurogenic claudication. The scans were interpreted independently by three neuro-radiologists who had no knowledge about the presence or absence of clinical symptoms in the subjects. About one-third of the subjects were found to have a substantial abnormality. Of those who were less than sixty years old, 20 per cent had a herniated nucleus pulposus and one had spinal stenosis. In the group that was sixty years old or older, the findings were abnormal on about 57 per cent of the scans: 36 per cent of the subjects had a herniated nucleus pulposus and 21 per cent had spinal stenosis. There was degeneration or bulging of a disc at at least one lumbar level in 35 per cent of the subjects between twenty and thirty-nine years old and in all but one of the sixty to eighty-year-old subjects. In view of these findings in asymptomatic subjects, we concluded that abnormalities on magnetic resonance images must be strictly correlated with age and any clinical signs and symptoms before operative treatment is contemplated.  相似文献   
47.
48.
49.
Deep venous thrombosis and pulmonary embolism   总被引:2,自引:0,他引:2  
All surgical patients are at risk for the development of deep venous thrombosis and subsequent pulmonary embolism or postphlebitic syndrome. The evolution of ultrasonographic imaging has increased the awareness of prevention, diagnosis, and treatment of deep venous thrombosis. Duplex imaging and Doppler color flow imaging have made the diagnosis of deep venous thrombosis relatively simple, painless, inexpensive, and definitive. These procedures have gained acceptance by both patients and physicians. Several risk factors have been identified that increase the chance of the development of deep venous thrombosis. These factors include a history of deep venous thrombosis, presence of a malignant process, increasing age, cigarette smoking, obesity, prolonged bed rest, and general anesthesia. The greater the number of risk factors, the more aggressive prophylaxis should be. Means of prophylaxis have improved, and surgeons now generally agree that some form of prophylaxis is required. Heparin and intermittent compression devices appear to be equally effective in preventing deep venous thrombosis. The addition of venous monitoring in high-risk patients permits immediate identification of the presence of deep venous thrombosis. During the last decade, the treatment of patients with deep venous thrombosis has changed little. Heparin followed by warfarin remains the treatment of choice. A small group of patients receive fibrinolytic therapy for deep venous thrombosis. Although the incidence of postoperative deep venous thrombosis has decreased during the last decade, it remains a significant complication.  相似文献   
50.
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