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   8121篇
  免费   744篇
  国内免费   25篇
耳鼻咽喉   108篇
儿科学   232篇
妇产科学   257篇
基础医学   1053篇
口腔科学   159篇
临床医学   681篇
内科学   1925篇
皮肤病学   114篇
神经病学   625篇
特种医学   271篇
外科学   1177篇
综合类   77篇
一般理论   3篇
预防医学   781篇
眼科学   132篇
药学   616篇
中国医学   22篇
肿瘤学   657篇
  2023年   59篇
  2022年   105篇
  2021年   237篇
  2020年   126篇
  2019年   186篇
  2018年   251篇
  2017年   172篇
  2016年   196篇
  2015年   220篇
  2014年   297篇
  2013年   393篇
  2012年   549篇
  2011年   586篇
  2010年   300篇
  2009年   276篇
  2008年   476篇
  2007年   488篇
  2006年   464篇
  2005年   453篇
  2004年   430篇
  2003年   394篇
  2002年   355篇
  2001年   183篇
  2000年   195篇
  1999年   142篇
  1998年   71篇
  1997年   44篇
  1996年   53篇
  1995年   62篇
  1994年   44篇
  1993年   46篇
  1992年   85篇
  1991年   55篇
  1990年   77篇
  1989年   65篇
  1988年   53篇
  1987年   72篇
  1986年   74篇
  1985年   54篇
  1984年   58篇
  1983年   36篇
  1982年   40篇
  1981年   42篇
  1980年   29篇
  1979年   36篇
  1978年   33篇
  1977年   20篇
  1975年   20篇
  1973年   21篇
  1972年   19篇
排序方式: 共有8890条查询结果,搜索用时 31 毫秒
101.
Cranial and spinal infections are severe events that require timely diagnosis and treatment. Physical and neurological examination, laboratory tests and radiological imaging may be insufficient for assessing cranial and spinal septic lesions. This study aimed to evaluate the accuracy of indium-111 white blood cell (WBC) scan in assessing the presence of leucocytes in intracranial and spinal lesions, and in the diagnosis, management and follow-up of primary, post-traumatic and post-surgical infections. One hundred and twenty-four subjects were included in the study (48 with post-traumatic or post-surgical lesions, 73 with primary cerebral lesions, and 3 with spinal lesions). All patients underwent a diagnostic work-up including planar scans with 111In-labelled WBCs, at 4 and 24 h post tracer injection. All subjects underwent surgical treatment. Patients who did not recover from the infection as suggested by clinical evolution underwent further treatment (up to three times) and further WBC scans (up to four times). WBC scintigraphy correctly identified all the areas of leucocyte accumulation, as confirmed after surgery. WBC scintigraphy also correctly excluded the presence of leucocytes in all other lesions, as demonstrated at surgery. The results of this study confirm the accuracy of WBC scan for the assessment of patients with cranial and spinal lesions, in whom the demonstration of leucocyte accumulation can ease the diagnosis of infection, and indicate that the method is also accurate for the follow-up and management of neurosurgical patients.  相似文献   
102.
103.
Vivian  W.  Pinn  林芸 《美国医学会杂志》2006,25(2):113-116
与当代生物医学及行为研究的某些挑战比较,近年来,妇女健康研究概念的延伸和扩展是平行甚至超前的。15年前,妇女健康研究主要集中在生殖健康方面。尽管女性并非总被排除于生殖系统之外的临床研究,但是在同时涉及女性和男性的临床试验并未常规确定女性与男性的差别。为了拓宽女性健康的概念,加之认识到绝经后妇女的增多,研究的倡导者强调需要阐明女性一生的健康状态,包括正常衰老的影响。  相似文献   
104.
105.
目的:探讨流式细胞仪交叉配型(flow cytometry crossmatch, FCXM)对移植肾一年存活率的影响。方法:应用χ2检验比较FCXM阳性与阴性组间1年移植肾死亡有无差异。以“移植后1年肾脏的存活状况(是/否)”为应变量,以移植后早期排斥反应(移植后1月内发生)、血管性排斥反应、移植肾功能延迟(移植后1周内需做血液透析)、FCXM、群体抗原反应抗体(PRA)、 HLA A,B配型、HLA DR配型、供者类型(尸肾/活体供肾)、既往移植次数、免疫抑制药物的使用、血清巨细胞病毒状态、冷缺血时间、供者和受者年龄等可疑影响因素为自变量建立Logistic回归模型,探讨流式细胞仪交叉配型对移植肾1年存活有无影响。结果:258例患者平均随访时间为25个月(12~60个月),期间30例移植肾死亡,其中23例发生在移植后1年内。 χ2检验显示,FCXM阳性与阴性组间1年移植肾死亡无统计学差异(P=0.157?0)。 Logistic 回归显示,对移植肾1年死亡有影响的因素包括移植肾功能延迟(OR=8.00, P=0.001?4),供者类型为尸肾(OR=9.30, P=0.001?7)和血管排斥反应(OR=5.05, P=0.021?9)。FCXM的结果不会影响移植肾一年存活率(OR=1.60, P=0.534?6)。结论: FCXM对移植肾1年后存活尚无肯定的影响。  相似文献   
106.
107.
108.
109.
The aim of this study was to examine the clinical presentation and time of hepatic artery thrombosis (HAT) after orthotopic liver transplantation (OLT), stressing the role of imaging modalities. Therapeutic options are described, such as retransplantation (Re-OLT), hepatic resections and revascularization procedures, focusing on complications and outcome in a consecutive series of 687 OLT. Over the period from 1986 to 1999, 687 OLT were carried out in 601 patients, 592 of whom were adults and 95 pediatric subjects. Of these operations 601 were primary OLT and 86 Re-OLT (71 I Re-OLT, 14 II Re-OLT and 1 III Re-OLT). In this retrospective study, we reviewed rejection episodes, time of HAT (early or late), possible cause of HAT, day of suspected diagnosis of HAT and day of confirmation of diagnosis. Clinical presentation, management, complications, outcome, survival rates and the need for Re-OLT were also recorded. The incidence of HAT was 2.47% (17/687). Early HAT (n = 9, < 30 days) was diagnosed 15.6 days after OLT (range: 3-25 days), whereas late HAT (n = 8, > 30 days) occurred 295.1 days after OLT (range: 38-1830 days). In two asymptomatic patients (2/17: 11.7%), HAT was discovered incidentally. Most of the patients (11/17: 64.7%) presented with increased liver function test values and fever. Relapsing bacteremia occurred in 7/17 cases (41.1%), whereas a biliary stricture and biliary leak were diagnosed in 3/17 (17.6%) and in 1/17 patients (5.8%), respectively. Fulminant hepatic failure was the clinical presentation in 2/17 cases (11.7%). In one case the clinical presentation was acute and chronic rejection (1/17: 5.8%). Intrahepatic abscesses were diagnosed in one case (1/17: 5.8%), as well as an intrahepatic haemorrhage (1/17: 5.8%). Doppler ultrasound (DUS) correctly revealed HAT in 9 of the 17 patients (52.9% sensitivity). In 8 of the 9 patients (88.8%) in whom HAT was diagnosed by DUS, angiography was also performed to confirm the diagnosis. Overall, angiography detected HAT in 14/17 patients (82.3% sensitivity). HAT management consisted of immediate Re-OLT in 6 patients 6.8 days (range: 3-12 days) after diagnosis. Delayed Re-OLT was performed in 6 patients 529.1 days (range: 68-1920 days) after diagnosis. The overall retransplantation rate was 70.5% (12/17). Two patients died despite undergoing intraarterial urokinase treatment. Three grafts were salvaged, but suffered biliary stricture due to ischemic cholangitis and underwent hepatico-jejunostomy. A II Re-OLT was carried out in 4 of 12 patients (33.3%). The overall mortality rate was 41.1% (7/17). One-year and 3-year overall survival rates were 58.8% (10/17) and 47.0% (8/17), respectively. Both 5- and 10-year overall survival rates were 11.7% (2/17). Although the results of OLT have improved dramatically over the past few years, HAT is still associated with substantial morbidity, a high incidence of graft failure and high mortality rates. The use of DUS to screen for HAT has permitted earlier diagnosis, but early angiographic evaluation of the hepatic arteries is still needed for accurate diagnosis of HAT and remains the gold standard. Retransplantation is the definitive solution for HAT in the majority of cases, though it is essentially the patient's clinical condition that dictates the form of management.  相似文献   
110.
Metastastic tumours involving the epididymis are rare and most often found in patients with disseminated disease. It is even more unusual when the metastasis of the epididymis is the first sign of tumour recurrence. We report a case of an asymptomatic recurrent colon carcinoma presenting as metastasis in the epididymis. Although metastatic cancer presenting as an intra-scrotal mass is extremely rare, it should be considered as a possibility in patients who present with a mass involving the testicle or epididymis.  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