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   513980篇
  免费   33362篇
  国内免费   614篇
耳鼻咽喉   6893篇
儿科学   16841篇
妇产科学   13522篇
基础医学   85015篇
口腔科学   14473篇
临床医学   44339篇
内科学   93609篇
皮肤病学   12157篇
神经病学   36189篇
特种医学   18463篇
外国民族医学   63篇
外科学   77036篇
综合类   8471篇
一般理论   118篇
预防医学   38969篇
眼科学   12136篇
药学   40538篇
中国医学   1006篇
肿瘤学   28118篇
  2018年   4930篇
  2015年   4509篇
  2014年   6060篇
  2013年   9547篇
  2012年   12870篇
  2011年   14270篇
  2010年   8300篇
  2009年   7772篇
  2008年   13693篇
  2007年   14696篇
  2006年   14939篇
  2005年   14357篇
  2004年   14049篇
  2003年   13390篇
  2002年   13267篇
  2001年   24067篇
  2000年   25079篇
  1999年   20556篇
  1998年   5426篇
  1997年   4705篇
  1996年   5041篇
  1995年   4625篇
  1994年   4318篇
  1993年   4136篇
  1992年   15727篇
  1991年   16310篇
  1990年   16422篇
  1989年   15796篇
  1988年   14576篇
  1987年   14419篇
  1986年   13599篇
  1985年   12975篇
  1984年   9627篇
  1983年   8247篇
  1982年   4559篇
  1981年   4229篇
  1979年   9418篇
  1978年   6855篇
  1977年   5772篇
  1976年   5603篇
  1975年   6396篇
  1974年   7634篇
  1973年   7132篇
  1972年   6960篇
  1971年   6685篇
  1970年   6174篇
  1969年   5888篇
  1968年   5559篇
  1967年   5012篇
  1966年   4450篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
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   
992.
993.
994.
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   
995.
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   
996.
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   
997.
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   
998.
999.
We describe physical symptoms and signs, laboratory data and psychosocial assessments for 84 children (age 1-17) hospitalized for the first time with suspected or definite rheumatic disease. At 16 months (range 7-28) followup change of disease severity was assessed based on hospital records. The patients were categorized as unchanged/worse (n = 36) or improved (n = 48). A linear discriminant model applying a combined set of 6 medical and 2 psychosocial variables characterized correctly 68 of 84 patients (81%). The variables were age at onset, disease severity, months of disease duration, presence of rheumatic disease in the family, erythrocyte sedimentation rate (ESR), thrombocytes, total behavior problem score on the Child Behavior Checklist and maternal distress. By discriminant function analysis of biopsychosocial variables more homogeneous groups may be obtained. Study of such groups may improve prediction of the prognosis.  相似文献   
1000.
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