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   34787篇
  免费   3458篇
  国内免费   45篇
耳鼻咽喉   417篇
儿科学   1102篇
妇产科学   962篇
基础医学   4756篇
口腔科学   782篇
临床医学   3736篇
内科学   7254篇
皮肤病学   453篇
神经病学   2744篇
特种医学   1325篇
外国民族医学   9篇
外科学   4405篇
综合类   766篇
一般理论   28篇
预防医学   3961篇
眼科学   831篇
药学   2411篇
中国医学   42篇
肿瘤学   2306篇
  2021年   463篇
  2020年   259篇
  2019年   461篇
  2018年   538篇
  2017年   460篇
  2016年   440篇
  2015年   471篇
  2014年   740篇
  2013年   1121篇
  2012年   1571篇
  2011年   1628篇
  2010年   884篇
  2009年   808篇
  2008年   1442篇
  2007年   1567篇
  2006年   1523篇
  2005年   1404篇
  2004年   1283篇
  2003年   1264篇
  2002年   1281篇
  2001年   1141篇
  2000年   1185篇
  1999年   998篇
  1998年   398篇
  1997年   373篇
  1996年   411篇
  1995年   354篇
  1994年   347篇
  1993年   337篇
  1992年   929篇
  1991年   916篇
  1990年   835篇
  1989年   797篇
  1988年   703篇
  1987年   723篇
  1986年   724篇
  1985年   695篇
  1984年   563篇
  1983年   436篇
  1982年   352篇
  1981年   295篇
  1980年   261篇
  1979年   532篇
  1978年   325篇
  1977年   269篇
  1976年   288篇
  1975年   328篇
  1974年   353篇
  1973年   293篇
  1972年   273篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
31.
32.
Abstract We report a case of SMV injury in a critically ill patient. The patient was a 19-year-old woman involved in a motor vehicle collision. Her injuries included grade II splenic and renal lacerations, devascularized and lacerated right and transverse colon, a transected transverse mesocolon, a massive shear injury of her abdominal wall, and two partial SMV transections. At initial damage control laparotomy, the SMV was ligated, the devascularized bowel resected and a temporary abdominal closure applied. At re-operation, a mesocaval shunt using saphenous vein was employed. The shunt failed and the patient required a saphenous vein jump graft. Although visceral vascular injuries are rare, ligation of the SMV in a damage control situation is acceptable. This case study is the first to discuss appropriate treatment when interruption to a patient's collateral visceral venous drainage limits the surgeon’s ability to ligate. In these situations, bypass shunts may be successful.  相似文献   
33.
The authors describe a method for silicone intubation of a single patent canaliculus associated with a nasolacrimal duct obstruction. Although bicanalicular intubation is always preferable when possible, unicanalicular stenting is necessary when only one canaliculus is patent. A chief advantage of this technique is that the lacrimal stent is inaccessible to the child and thus cannot be accidentally pulled out.  相似文献   
34.
35.
The objective of this study is to determine whether a normal fetal morphology ultrasound scan in women older than 35 years reduces the risk of aneuploidy. We reviewed the results of amniocentesis and second trimester sonogram in all women older than 35 years from 1991 to 1995. None had prior screening. We excluded fetuses with structural anomalies. We determined the sensitivity and specificity of minor markers in detecting Down syndrome and also determined the reduction in risk of a normal sonogram. Among the 2060 women older than 35 years giving birth during the study period, 16 (0.78%) delivered an infant with Down syndrome. Of the 16 fetuses, two had no prenatal testing or ultrasound, two had invasive testing but no second trimester sonogram, five had a normal sonogram and seven had one or more sonographic markers of Down syndrome. At least 17% of women older than 35 years did not participate in prenatal testing or ultrasound. Ultrasound detected Down syndrome with a sensitivity of 59% (95% confidence interval: 45–72%), a false‐positive rate of 10.6% (9.4–11.8%) and a positive predictor value of 1 in 9. The likelihood of having normal karyotype if the sonogram was normal was 0.46 (0.31–0.61). In women older than 35 years, a normal second trimester sonogram reduces the risk of Down syndrome by more than 50%. At least 17% of women older than 35 years do not participate in prenatal testing or ultrasound.  相似文献   
36.
37.
38.
Stent fracture is uncommon but may have consequences including restenosis. To date, stent fractures reported have been related to aggressive post dilation. We describe a case that involves fracture of a stent deployed to nominal pressure. Unlike most stent fractures reported that involve stent struts only our case demonstrated circumferential disruption with complete separation of the stent segments.  相似文献   
39.
Wound assessment is a key element of effective wound care, and assessment of pressure ulcers includes accurate determination of wound stage. Although the original staging system established by Shea was based on his understanding of the pathology involved in pressure ulcer development, subsequent staging systems (and the one currently in use) were intended simply to establish the level of tissue damage. Recently, clinicians have drawn attention to numerous limitations associated with the current staging system, including the inability to differentiate between an inflammatory response involving intact skin and a deep tissue injury (deep bruising) underneath intact skin. This is a clinically significant difference because clinicians have noted that most inflammatory responses resolve with intervention, whereas most areas of deep tissue injury progress to full-thickness ulcers even when appropriate intervention is provided. A second area of controversy involves partial-thickness (Stage 2) lesions; because many of these lesions are caused by maceration and/or friction (as opposed to pressure) clinicians are frequently unclear regarding which of these lesions should be staged. In response to these concerns, the National Pressure Ulcer Advisory Panel convened a consensus forum and published white papers to clearly outline the issues; they solicited clinician feedback on the white papers and the Wound, Ostomy, Continence Nurses Society provided a written response. This article summarizes the key points of the white papers, WOCN Society response, and consensus forum discussion.  相似文献   
40.
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