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   34271篇
  免费   3407篇
  国内免费   60篇
耳鼻咽喉   414篇
儿科学   1077篇
妇产科学   957篇
基础医学   4716篇
口腔科学   759篇
临床医学   3633篇
内科学   7112篇
皮肤病学   441篇
神经病学   2723篇
特种医学   1251篇
外国民族医学   9篇
外科学   4371篇
综合类   756篇
一般理论   28篇
预防医学   3931篇
眼科学   828篇
药学   2407篇
中国医学   37篇
肿瘤学   2288篇
  2021年   455篇
  2020年   254篇
  2019年   455篇
  2018年   519篇
  2017年   450篇
  2016年   423篇
  2015年   457篇
  2014年   724篇
  2013年   1114篇
  2012年   1559篇
  2011年   1616篇
  2010年   860篇
  2009年   762篇
  2008年   1420篇
  2007年   1573篇
  2006年   1514篇
  2005年   1411篇
  2004年   1280篇
  2003年   1252篇
  2002年   1272篇
  2001年   1134篇
  2000年   1178篇
  1999年   992篇
  1998年   378篇
  1997年   348篇
  1996年   386篇
  1995年   327篇
  1994年   325篇
  1993年   316篇
  1992年   923篇
  1991年   914篇
  1990年   834篇
  1989年   784篇
  1988年   696篇
  1987年   716篇
  1986年   700篇
  1985年   688篇
  1984年   556篇
  1983年   437篇
  1982年   350篇
  1981年   291篇
  1980年   262篇
  1979年   533篇
  1978年   323篇
  1977年   266篇
  1976年   294篇
  1975年   322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 62 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