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   515111篇
  免费   33417篇
  国内免费   620篇
耳鼻咽喉   6899篇
儿科学   16924篇
妇产科学   13534篇
基础医学   85155篇
口腔科学   14522篇
临床医学   44417篇
内科学   93861篇
皮肤病学   12173篇
神经病学   36342篇
特种医学   18486篇
外国民族医学   63篇
外科学   77175篇
综合类   8476篇
一般理论   118篇
预防医学   39050篇
眼科学   12142篇
药学   40600篇
中国医学   1006篇
肿瘤学   28205篇
  2018年   4954篇
  2015年   4542篇
  2014年   6092篇
  2013年   9594篇
  2012年   12933篇
  2011年   14344篇
  2010年   8352篇
  2009年   7804篇
  2008年   13760篇
  2007年   14750篇
  2006年   14999篇
  2005年   14411篇
  2004年   14101篇
  2003年   13435篇
  2002年   13297篇
  2001年   24093篇
  2000年   25110篇
  1999年   20585篇
  1998年   5441篇
  1997年   4713篇
  1996年   5048篇
  1995年   4633篇
  1994年   4323篇
  1993年   4140篇
  1992年   15738篇
  1991年   16328篇
  1990年   16438篇
  1989年   15808篇
  1988年   14592篇
  1987年   14435篇
  1986年   13615篇
  1985年   12995篇
  1984年   9638篇
  1983年   8257篇
  1982年   4570篇
  1981年   4235篇
  1979年   9423篇
  1978年   6858篇
  1977年   5781篇
  1976年   5604篇
  1975年   6399篇
  1974年   7635篇
  1973年   7136篇
  1972年   6964篇
  1971年   6687篇
  1970年   6173篇
  1969年   5889篇
  1968年   5559篇
  1967年   5013篇
  1966年   4450篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
991.
The natural killing of K 562 cells by whole blood from normal subjects was comparable with that shown by separated mononuclear cells. In order to establish the conditions for a reliable natural killer assay by using very small numbers of effector cells in whole blood, the isotope uptake of target cells was increased by a modified labelling method, which permitted the use of fewer target cells in the assay. The natural cytotoxicity of whole blood was augmented by interferon to the same extent as observed with separated mononuclear cells. The chemiluminescence of granulocytes in whole blood comparable with that of separated granulocytes. Taken together, these methods are considerably less tedious than the conventional methods, technique is also economical, and the results may reflect in vivo cytolytic processes much better.  相似文献   
992.
A data system which enables utilization of individual patient data by public health nurses, physicians and home helpers, is required both for the continuous and comprehensive monitoring of the various needs of the aged receiving care services at home in the local district and for facilitating welfare services. Therefore, an experimental and comprehensive system for public health, medical services and welfare was put into practice for district public health services for the aging society. The results of this trial system shows that this system is useful indeed for the welfare services, though it also has several problems.  相似文献   
993.
Moscow Scientific Research Institute of Roentgenoradiology. Translated from Meditsinskaya Tekhnika, No. 2, pp. 6–8, March–April, 1992.  相似文献   
994.
In the fasting state, antral motor activity is similar in preterm and term infants, but the antral responses to feeding have not been compared in preterm and term infants. The purpose of this study was to use low-compliance, continuous perfusion manometry to compare antral and duodenal feeding responses in 13 preterm and nine term infants within the first 14 days of life. Confirming our previous studies, fasting antral motor activity was similar in preterm and term infants, but duodenal activity differed. Individual duodenal cluster activity was of shorter duration in preterm than in term infants (p less than 0.01). Motor activity in antrum and duodenum changed in both groups of infants in response to an intraduodenal milk infusion of 4 ml/kg/2 h; however, the nature of the change varied in the two regions. In term infants, the number of antral pressure waves, the duration of antral clusters, and the antral motility index decreased by one third or more during feeding when compared with fasting (all p less than 0.05). In contrast to the decrease in antral activity in response to feeding, the duodenal motility index and cluster activity increased significantly during feeding compared with fasting (both p less than 0.05). The divergent response of antral and duodenal motor activity in response to feedings was also seen in preterm infants. Antral pressure waves, the duration of antral clusters, and the antral motility index were decreased during feeding (all p less than 0.005 or less).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
995.
996.
997.
Thrombosis of the internal jugular and subclavian vein is often caused by central venous catheters. We report on a 39-year-old patient suffering from clinically suspected thrombosis of the internal jugular and subclavian veins. Thrombosis was confirmed by B-mode-sonography. The development of thrombosis in this case as a consequence of a central venous catheter and of an additional continuous i.v. treatment with human granulocyte/macrophage colony-stimulating factor (GM-CSF) is discussed.  相似文献   
998.
A case of bilateral blepharospasm who registered the efficacy of edrophonium was reported. The case is a 49-year-old female. She had been in good health until January, 1991 when she complained of difficulty in opening her eyes while driving. Thereafter the condition progressed to such a degree that she was unable to experience a comfortable life. Her blinking rate did not changed. The symptoms were triggered by stress or some physical action, such as walking or driving. They were attenuated by taking a bath, sleep or sedation. The severity of the symptoms varied during the day and from day to day. Neurological examination revealed bilateral spasms of the orbicular oculi muscles, and occasionally of the orbicular oris muscles, sternocleidmastoid muscles and the perinasal regions. Neither orolingual dyskinesia nor other involuntary movements were detected. Surface electromyography (EMG) disclosed tonic discharges mainly from the orbicular oculi muscles. The abnormal spasm disappeared with the injection of edrophonium chloride. The test for the serum antiacetylcholine receptor antibody was negative and a repetitive stimulation EMG showed no waning phenomenon. No thymoma or thymus abnormalities were detected by pneumomediastinography. A needle EMG revealed neurogenic change in the distal portion of the limbs. A single fiber EMG showed elongation of the jitter value and the blocking phenomenon. Although distigmine bromide was ineffective against the spasm, pyridostigmine bromide and the local injection of botulinum toxin were very effective.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
999.
Two cases are presented in which conventional approaches did not permit dilation of and stent placement in obstructed ureters. In patients with iatrogenic ureteral laceration or rigid ureteral kinking, direct percutaneous translumbar puncture may provide a safe alternative. The authors' technique is described.  相似文献   
1000.
Nurses working in primary health care settings often care for large numbers of clients in brief periods of time. Both clients and nurses express frustration toward the care provided in these circumstances. Development of a screening tool to identify high-risk clients could assist nurses in targeting interventions to these individuals; in turn, this has the potential for increasing nurse and client satisfaction. A general procedure for identifying persons at risk in primary health care settings is described. The procedure is illustrated with a specific population of clients--incarcerated women. Factors found important in assessing risk were social characteristics such as education, situational factors such as sentence length, and indicators of psychological distress such as depression. These broad categories may serve as a basis for the development of screening tools for a variety of populations.  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