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   74745篇
  免费   7356篇
  国内免费   3276篇
耳鼻咽喉   118篇
儿科学   4090篇
妇产科学   369篇
基础医学   6016篇
口腔科学   531篇
临床医学   7035篇
内科学   13107篇
皮肤病学   672篇
神经病学   1492篇
特种医学   1822篇
外国民族医学   7篇
外科学   28131篇
综合类   9813篇
现状与发展   16篇
一般理论   3篇
预防医学   1645篇
眼科学   1266篇
药学   3781篇
  22篇
中国医学   2991篇
肿瘤学   2450篇
  2024年   139篇
  2023年   1354篇
  2022年   1535篇
  2021年   3417篇
  2020年   2988篇
  2019年   3204篇
  2018年   3155篇
  2017年   2926篇
  2016年   2898篇
  2015年   2872篇
  2014年   4851篇
  2013年   5337篇
  2012年   3770篇
  2011年   4503篇
  2010年   3981篇
  2009年   3890篇
  2008年   3995篇
  2007年   4077篇
  2006年   3977篇
  2005年   3449篇
  2004年   2851篇
  2003年   2416篇
  2002年   1988篇
  2001年   1730篇
  2000年   1382篇
  1999年   1075篇
  1998年   966篇
  1997年   841篇
  1996年   798篇
  1995年   674篇
  1994年   734篇
  1993年   437篇
  1992年   551篇
  1991年   427篇
  1990年   283篇
  1989年   282篇
  1988年   268篇
  1987年   203篇
  1986年   163篇
  1985年   182篇
  1984年   155篇
  1983年   83篇
  1982年   107篇
  1981年   99篇
  1980年   67篇
  1979年   68篇
  1978年   61篇
  1977年   51篇
  1976年   41篇
  1975年   27篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
The use of livers from anti-hepatitis B core (HBc) positive donors can alleviate donor shortage. Nineteen of 367 (6%) adults receiving anti-HBc positive allografts [three were hepatitis B antigen (HBsAg) negative, hepatitis B antibody (HBsAb) positive; four were HBsAg positive and 12 were not exposed to hepatitis B viral (HBV) infection] were retrospectively reviewed. In HBsAg negative recipients, immunoprophylaxis (IP) was guided by viral serology and immunohistochemistry (IH) of day 0 and day 7 liver biopsies. If IH was negative, IP was stopped. None of three HBsAg negative, HBsAb positive recipients infected; one (replicating) of four HBsAg positive recipients reinfected and seven of eight (87.5%) HBsAg, HBsAb negative recipients, who did not receive long-term IP, infected after a median time of 2 years (range 1-5); one patient died of liver failure. Four HBsAg, HBsAb negative recipients, receiving life-long IP, remained infection free. Anti-HBc positive donor livers must be directed selectively first to HBsAg positive recipients, next to recipients having HBV antibodies and finally to HBV-naive recipients. Identification of both donor and recipient risk factors for HBV infection before transplantation allows indiscriminate use of antiviral prophylaxis. The necessity for IP therapy should be guided by HBV-DNA testing of donor liver tissue and serum. IH of early liver biopsies is an unreliable marker for predicting antiviral treatment requirements.  相似文献   
92.
93.
Pancreatic panniculitis is an uncommon condition that can occur in association with pancreatic disease. We present a case of pancreatic panniculitis in a female pancreas-kidney transplant recipient 5 months post-transplant. The patient was on standard immunosuppressive medications and had acute rejection of her renal allograft. The diagnosis of allograft pancreatitis and rejection presenting with pancreatic panniculitis was supported clinically, histopathologically and by laboratory and imaging data. This is the fourth case of pancreatic panniculitis occurring in a transplant recipient and the first in a simultaneous pancreas-kidney transplant recipient. It is also the first case associated with allograft rejection. Clinicians should be aware that pancreatic panniculitis may be a manifestation of underlying allograft pancreatic disease.  相似文献   
94.
The purpose of this study is to determine the role of liver biopsy and outcome of patients undergoing donor evaluation for adult-to-adult right hepatic lobe living donor liver transplantation (LDLT). Records of patients presenting for a comprehensive donor evaluation between 1997 and February 2005 were reviewed. Liver biopsy was performed only in patients with risk factors for abnormal histology. Two hundred and sixty patients underwent a comprehensive donor evaluation and 116 of 260 (45%) were suitable for donation, 14 of 260 (5.4%) did not complete evaluation and 130 of 260 (50%) were rejected. Four patients underwent unsuccessful hepatectomy surgery due to discovery of intraoperative abnormalities. Between 1997 and 2001, the acceptance rate of donor candidates (63%) was higher than 2002-2005 (36%), p < 0.0001. Sixty-six of the 150 eligible patients (44%) fulfilled criteria for liver biopsy and 28 of 66 (42%) had an abnormal finding. Less than half of the patients undergoing donor evaluation were suitable donors and the donor acceptance rate has declined over time. A large proportion of the patients undergoing liver biopsy have abnormal findings. Our evaluation process failed to identify 4 of 103 who had aborted donor surgeries.  相似文献   
95.
We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant.  相似文献   
96.
目的探讨移植肝缺血-再灌注损伤程度的评估方法及其与肝移植患者预后的关系。方法218例良性终末期肝病患者,在移植肝恢复血液灌注后1h采取外周静脉血,测定丙氨酸转氨酶浓度(定义为基础肝功能),同时采用组织气体分析仪测定肝组织的氧分压,并取肝组织活检,计算水变性及坏死细胞百分比,分别对上述3项指标进行评分,再根据各指标得分之和将缺血-再灌注损伤程度划分为5级(0~Ⅳ级),统计围手术期(术后2周内)、术后近期(术后2周至1个月)、术后中远期(1个月以上)的患者死亡率。结果移植肝缺血再灌注损伤程度评为0级者157例(A组),死亡7例(4.5%),71.4%(5/7)死于术后3-6个月;缺血-再灌注损伤程度评为Ⅰ级者25例(B组),死亡5例(20.0%),80.0%(4/5)死于术后2周至3个月;缺血-再灌注损伤程度评为Ⅱ级者23例(C组),死亡5例(21.7%),80.0%(4/5)死于术后2周至3个月;缺血-再灌注损伤程度评为Ⅲ级者8例(D组),死亡7例(87.5%),85.7%(6/7)死于术后1个月内;缺血-再灌注损伤程度评为Ⅳ级者5例(E组),全部死亡,80.0%(4/5)死于术后1个月内。A组各期死亡率明显低于B组、C组(P〈0.05)和D组、E组(P〈0.01);B组、C组间各期死亡率的差异无统计学意义(P〉0.05);B组、C组各期死亡率均低于D组、E组(P〈0.05)。结论基础肝功能、组织氧分压以及水变性和坏死细胞百分比三项指标可基本反映移植肝缺血-再灌注损伤程度;缺血-再灌注损伤评级达Ⅲ~Ⅳ级者术后死亡率较高。  相似文献   
97.
Implantation of left ventricular assist devices (LVAD) is associated with HLA antibody sensitization. The objective of this study was to determine the specificity of antibodies produced by LVAD recipients using a combination of ELISA, Luminex and microcytotoxicity assays. Fifty-one LVAD patients were studied, from 44 to 838 days post-implantation. No patient developed HLA antibodies, although 24 produced IgG antibodies detectable in both ELISA and Luminex assays. These antibodies manifest as positive reactions with class I and class II wells of the ELISA and also blank wells. In Luminex assays, they produce high MFI readings with the negative control beads. Antibodies were detected 18 to 228 days after implantation. This reactivity was found to be directed against bovine serum albumin (BSA), commonly used to block non-specific binding in ELISA and Luminex assays; absorption of sera with BSA-coated beads completely abrogated reactivity in all solid phase assays, but did not eliminate anti-HLA antibodies in control sera. Ten of the 24 patients have proceeded to transplantation, with a 1-year graft survival of 69%. In conclusion, it appears that implantation of LVADS disrupts immunoregulatory pathways leading to production of anti-albumin antibodies. These can be misinterpreted as anti-HLA antibodies in solid phase assays.  相似文献   
98.
99.
趾蹼血管分型的临床认识   总被引:2,自引:2,他引:0  
目的分析120例足趾移植再造手指病例,对趾蹼间的血管形态和交通情况进行观察,并阐述其临床意义。方法临床观察120例156侧趾蹼,对第一跖骨背动脉和第一趾底动脉在趾蹼间的走向、口径以及两者的交通支情况进行记录并进行分型。结果按孙博的分型方法:Ⅰ型72侧,占46.2%;Ⅱ型57侧,占36.5%;Ⅱ型7侧,占4.5%;Ⅳ型3侧,占1.9%;Ⅴ型15侧,占9.6%;另有2侧(占1.3%)第一跖骨背血管口径〉1mm,虽发出趾背动脉供养蹲趾胫侧和第二趾腓侧,但在趾蹼内与趾底血管无吻合,故称之为孙博Ⅵ型。结论(1)从解剖形态看应增加孙博Ⅵ型较全面;(2)从临床实用角度出发,趾蹼间血管可以简单分为三型:Ⅰ型交通支口径在0.5mm以上。Ⅱ型交通支在0.5mm以下。Ⅲ型无交通;(3)手术中采用第一套或第二套供血系统,首先要看趾蹼间血管的交通支,即按本组的分型属Ⅰ型采用第一套供血系统,Ⅱ、Ⅲ型采用第二套供血系统。  相似文献   
100.
目的探讨磁共振成像在肝移植并发症诊断中的价值。方法回顾分析11例肝移植术后发生并发症者的磁共振检查影像资料。结果11例患者术后出现皮肤和巩膜黄染、发热以及尿黄等症状,丙氨酸转氨酶、天冬氨酸转氨酶、γ-谷氨酰转移酶和胆红素升高.经B型超声波检查不能明确原因,采用磁共振(MRI、MRA和MRCP)检查,明确肝动脉吻合口狭窄1例;肝动脉闭塞2例;下腔静脉吻合口狭窄及血栓形成各1例;胆管吻合口狭窄4例,其中1例伴胆汁瘤形成;肝门水平非吻合口狭窄6例;肝坏死2例;肝包膜下血肿及右肾上腺出血各1例;均显示不等量的右侧胸腔积液、腹腔积液及肝门部水肿。结论磁共振一次检查可显示肝内外的多种结构,能为肝移植术后并发症的诊断提供丰富的肝脏、血管、胆道以及肝外结构的图像信息。  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