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   1688篇
  免费   99篇
  国内免费   22篇
耳鼻咽喉   1篇
儿科学   151篇
妇产科学   17篇
基础医学   178篇
口腔科学   47篇
临床医学   161篇
内科学   384篇
皮肤病学   27篇
神经病学   37篇
特种医学   475篇
外科学   109篇
综合类   28篇
预防医学   53篇
眼科学   13篇
药学   66篇
中国医学   3篇
肿瘤学   59篇
  2022年   5篇
  2021年   9篇
  2020年   9篇
  2019年   7篇
  2018年   20篇
  2017年   10篇
  2016年   23篇
  2015年   30篇
  2014年   26篇
  2013年   61篇
  2012年   28篇
  2011年   25篇
  2010年   73篇
  2009年   59篇
  2008年   39篇
  2007年   28篇
  2006年   28篇
  2005年   21篇
  2004年   19篇
  2003年   16篇
  2002年   23篇
  2001年   17篇
  2000年   22篇
  1999年   26篇
  1998年   134篇
  1997年   120篇
  1996年   124篇
  1995年   91篇
  1994年   75篇
  1993年   81篇
  1992年   25篇
  1991年   22篇
  1990年   16篇
  1989年   59篇
  1988年   47篇
  1987年   49篇
  1986年   45篇
  1985年   48篇
  1984年   25篇
  1983年   31篇
  1982年   34篇
  1981年   20篇
  1980年   36篇
  1979年   14篇
  1978年   15篇
  1977年   17篇
  1976年   23篇
  1975年   25篇
  1974年   3篇
  1966年   2篇
排序方式: 共有1809条查询结果,搜索用时 15 毫秒
141.
142.
143.
A prospective evaluation of color flow mapping and real-time ultrasound was performed to determine if pseudoaneurysms could be distinguished from other causes of masses surrounding vascular grafts of the lower extremities. Twelve palpable pulsatile masses were imaged. Diagnoses were confirmed at angiography (n = 11), computed tomography (n = 7), aspiration biopsy (n = 5), and operative intervention (n = 6). A swirling pattern of blood flow was seen in six of seven cases of pseudoaneurysm. Lack of flow signals was noted in four of the five collections representing hematoma (n = 2) or infection (n = 2). The seventh case was later shown to be an infected, thrombosed pseudoaneurysm. The single false-positive diagnosis was made early in the series when the flow signals detected were due to transmitted arterial pulsations. The authors conclude that color Doppler flow imaging is useful in the differential diagnosis of pulsatile masses associated with prosthetic grafts. Prosthetic graft pseudoaneurysms have a specific appearance of swirling blood flow arising from a wide neck and are distinguishable from traumatic or iatrogenic pseudoaneurysms of the native vascular tree.  相似文献   
144.
Aim : To investigate whether infants with intrauterine growth retardation (IUGR) experience different changes in temperature and cortisol excretion after routine immunization compared with normal healthy infants. Methods : Overnight deep body temperature and urinary cortisol to creatinine ratios were measured on the night after immunization and a control night in normal and IUGR infants. Results : In 60 normal infants, first vaccination at about 10 wk of age led to a significant increase in minumum overnight temperature compared to the control night, mean rise 0.25°C (95% CI, 0.12 to 0.38). In 35 IUGR infants the mean rise in temperature between immunization night and control night was 0.35°C (95% CI, 0.15 to 0.55). The increases in minimum temperature did not differ significantly between the normal and IUGR infants ( p = 0.11). Cortisol to creatinine ratios measured from overnight urine samples showed that 23 IUGR infants had consistently higher levels than 39 normal infants; control night medians 34 and 15 ( p = 0.01) and immunization night medians 56 and 26 ( p= 0.02), respectively. However, the percentage increase did not differ significantly between the IUGR infants and the normal infants. A smaller number of second immunizations were studied, but no significant differences were found.

Conclusion : These results suggest that although the impact of immunization is the same for IUGR and normal infants, because IUGR infants are less mature and at greater stress before immunization, the absolute levels that they experience after immunization are higher than those for normal infants.  相似文献   
145.
146.
147.
The first case of Dupuytren's contracture in a black patient with no obvious caucasian admixture was reported in 1979. This condition is rare in the purely black population and since 1979 only 23 cases have been reported. We present the case of a black man with no history of caucasian admixture with bilateral Dupuytren's contracture. We suggest that this condition may not be as rare as the literature suggests and, that canvassing other hand societies for their experience, particularly in the continent of Africa, may help to establish the true incidence of this condition.  相似文献   
148.
A new tray has been designed for use during procedures involving needles and other sharp objects. The tray includes a foam adhesive pad, marked into 10 sections, into which the sharp objects can be placed point first. After the procedure, the objects can be safely withdrawn by their handles and then discarded. The tray has been used in more than 250 procedures.  相似文献   
149.
Jaundice develops in many patients with liver metastases from colorectal adenocarcinoma during hepatic arterial infusion chemotherapy (HAIC). The usual cause is thought to be hepatotoxicity from the chemotherapeutic agent or biliary obstruction from progressive neoplastic disease. The authors evaluated the abdominal computed tomography and ultrasound examinations performed on 49 patients who were jaundiced during long-term HAIC. In only one patient was diffuse intrahepatic biliary dilatation caused by an obstructing mass in the porta. Two patients had metastatic hepatic lesions causing focal biliary obstruction. Intrahepatic dilatation without an obstructing mass occurred in 20 patients. Percutaneous or endoscopic cholangiograms were commonly interpreted prospectively as showing extrinsic compression by metastases, but no mass was confirmed on imaging studies. Seven patients had focal intrahepatic ductal dilatation from stricture without an associated mass. The remaining 19 patients had normal-caliber ducts; their jaundice was caused by chemical hepatitis. This series suggests that the most common causes of jaundice in these patients are chemical hepatitis and common bile duct stricture, complications of intraarterial chemotherapy, rather than neoplastic obstruction. Stricture formation may be confused with extrinsic compression on direct cholangiograms.  相似文献   
150.
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