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   25682篇
  免费   1229篇
  国内免费   86篇
耳鼻咽喉   314篇
儿科学   645篇
妇产科学   635篇
基础医学   3368篇
口腔科学   1608篇
临床医学   1880篇
内科学   6172篇
皮肤病学   521篇
神经病学   1935篇
特种医学   548篇
外科学   2904篇
综合类   125篇
一般理论   13篇
预防医学   3066篇
眼科学   387篇
药学   1724篇
  1篇
中国医学   144篇
肿瘤学   1007篇
  2023年   229篇
  2022年   153篇
  2021年   552篇
  2020年   345篇
  2019年   611篇
  2018年   1067篇
  2017年   638篇
  2016年   655篇
  2015年   798篇
  2014年   844篇
  2013年   1149篇
  2012年   2065篇
  2011年   2270篇
  2010年   1026篇
  2009年   695篇
  2008年   1723篇
  2007年   1834篇
  2006年   1624篇
  2005年   1576篇
  2004年   1390篇
  2003年   1284篇
  2002年   1181篇
  2001年   448篇
  2000年   495篇
  1999年   366篇
  1998年   106篇
  1997年   50篇
  1996年   51篇
  1995年   45篇
  1994年   36篇
  1993年   43篇
  1992年   221篇
  1991年   158篇
  1990年   136篇
  1989年   118篇
  1988年   103篇
  1987年   101篇
  1986年   91篇
  1985年   72篇
  1984年   56篇
  1983年   56篇
  1979年   32篇
  1975年   38篇
  1974年   50篇
  1973年   29篇
  1971年   34篇
  1970年   36篇
  1969年   32篇
  1968年   38篇
  1967年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
OBJECTIVE: To evaluate the dynamics of bacterial contamination of healthcare workers' (HCWs) hands during neonatal care. SETTING: The 20-bed neonatal unit of a large acute care teaching hospital in Geneva, Switzerland. METHODS: Structured observation sessions were conducted. A sequence of care began when the HCW performed hand hygiene and ended when the activity changed or hand hygiene was performed again. Alcohol-based handrub was the standard procedure for hand hygiene. An imprint of the five fingertips of the dominant hand was obtained before and after hand hygiene and at the end of a sequence of care. Regression methods were used to model the final bacterial count according to the type and duration of care and the use of gloves. RESULTS: One hundred forty-nine sequences of care were observed. Commensal skin flora comprised 72.4% of all culture-positive specimens (n = 360). Other microorganisms identified were Enterobacteriaceae (n = 55, 13.8%); Staphylococcus aureus (n = 10, 2.5%); and fungi (n = 7, 1.8%). Skin contact, respiratory care, and diaper change were independently associated with an increased bacterial count; the use of gloves did not fully protect HCWs' hands from bacterial contamination. CONCLUSIONS: These data confirm that hands become progressively contaminated with commensal flora and potential pathogens during neonatal care, and identify activities at higher risk for hand contamination. They also reinforce the need for hand hygiene after a sequence of care, before starting a different task, and after glove removal.  相似文献   
32.

Background  

The justification for Nazi programs involving involuntary euthanasia, forced sterilisation, eugenics and human experimentation were strongly influenced by views about human dignity. The historical development of these views should be examined today because discussions of human worth and value are integral to medical ethics and bioethics. We should learn lessons from how human dignity came to be so distorted to avoid repetition of similar distortions.  相似文献   
33.
This case report demonstrates how extracting a maxillary deciduous canine affects the eruption path of a labially displaced ectopically erupting permanent canine. A long-term follow-up is presented, and the biologic mechanisms are discussed.  相似文献   
34.
Percutaneous embolization of large portosystemic collaterals was performed in three patients following placement of a transjugular intrahepatic portosystemic shunt in order to improve hepatopetal portal flow. Improved hepatic portal perfusion was achieved in these cases, thereby theoretically reducing the risk of chronic hepatic encephalopathy.  相似文献   
35.
Summary Nerve regeneration was studied in a model of centrocentral anastomosis (CCA) performed on the sciatic nerve of the rat. Experimental CCA was made by suturing the proximal end of the peroneal branch on the proximal end of the sural branch, placing between them a peroneal nerve graft (Group I, 20 rats) or a silicone chamber (Group II, 12 rats). Nerve grafts had a length of 5mm and silicone chambers 7 mm. In six silicone chambers an 1 mm nerve graft was placed in the centre of the tube. In group I animals anterograde degeneration was studied by cutting the graft 60 days after surgery. In group II, nerve regeneration was studied 2, 4 and 8 weeks after surgery. Results indicate that in CCA: 1) regenerated axons coming from one nerve end grow into the graft but do not cross the contralateral suture line; 2) regeneration is poorer in silicone chambers than in nerve grafts; and, 3) in silicone chambers regeneration is related to time. The reduction in the regenerative capability in CCA seems to be related to the alteration of nerve sprouts aiming for the peripheral targets.  相似文献   
36.
We have designed a double-lumen inflatable needle for the atraumatic dissection of brain substance. This balloon needle has been successfully used for the ventricular approach in brain grafting procedures to obtain a rounded corticotomy with a diameter of 1.5-2 cm in the treatment of Parkinson's disease.  相似文献   
37.
Nine publications are reviewed concerning blood pressure (BP) levels among Amerindian tribes of the Amazon Basin. The lifestyle of these lowland peoples includes most known protective factors against hypertension, and relative isolation from Western society. The latter, however, is rapidly changing. Sampling, data, and analysis problems make current blood pressure data difficult to interpret, and provide a questionable baseline from which to document pressure change during rapid culture change for these groups. Ethnographic and epidemiological perspectives are offered for future blood pressure and health studies among native Amazonians.  相似文献   
38.
39.
After total gastrectomy, the ileocecal graft may act as a reservoir and protect against reflux but give rise to transposition of the ileum and cause possible changes in bile acid metabolism and nutrition. This study compared the ileocecal graft and jejunal pouch. Male Wistar rats weighing 265 +/- 22 g were submitted to sham operation (S), ileocecal interposition graft (IIG), and jejunal pouch interposition graft (JP) after total gastrectomy. Eight weeks later, the esophagus was examined for evidence of esophagitis. Nutritional biochemistry and weight profile were documented preoperatively and 8 weeks after surgery. The oral glucose tolerance test was performed. Thirty-three rats were operated on and 30 survived for 8 weeks. Esophagitis occurred in seven JP rats. Body weight was significantly higher in IIG than in JP rats (p < .05). Normal glucose tolerance to intragastric glucose load was observed in sham and operated rats. JP rats had a significant decrease in serum albumin, glucose, transferrin, hemoglobin, iron, folate, and calcium, compared to sham (p < .05). Cobalamine was significantly lower in IIG rats than in JP rats (p < .05). In the IIG and JP groups, serum/hepatic total bile acid did not differ significantly from preoperative and sham values. In conclusion, the IIG interposition graft in rats prevented esophagitis, preserved nutrition, and did not interfere with enterohepatic total bile acid circulation.  相似文献   
40.
Apical ballooning is a novel clinical entity reported in different contexts of physical and psychological stress, which is more common in middle-aged women. Of unknown etiology, the syndrome is characterized by a sudden and transient dilatation of the left ventricular apex in the absence of obstructive atherosclerotic coronary disease or evidence of myocardial necrosis, with total late recovery of ventricular function. The authors report the case of a 53-year-old woman who was admitted to the emergency room with left arm ischemia and low cardiac output, requiring ventilatory support. Left catheterization showed typical medial and apical myocardial dysfunction, with normal coronary arteries. Transesophageal echocardiography revealed a thrombus attached to the lower face of the aortic arch, which probably explained the thromboembolism of the arm but was unlikely to be the cause of the left ventricular dysfunction since there were no enzymatic or electrocardiographic signs of myocardial necrosis and normal wall motion was fully recovered.  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