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   139645篇
  免费   12268篇
  国内免费   6297篇
耳鼻咽喉   409篇
儿科学   4398篇
妇产科学   696篇
基础医学   8894篇
口腔科学   876篇
临床医学   20077篇
内科学   20421篇
皮肤病学   695篇
神经病学   8954篇
特种医学   6152篇
外国民族医学   8篇
外科学   27625篇
综合类   25683篇
现状与发展   17篇
一般理论   3篇
预防医学   7093篇
眼科学   1444篇
药学   12627篇
  125篇
中国医学   8424篇
肿瘤学   3589篇
  2024年   516篇
  2023年   2744篇
  2022年   4750篇
  2021年   7241篇
  2020年   6197篇
  2019年   5118篇
  2018年   4823篇
  2017年   5312篇
  2016年   5608篇
  2015年   5371篇
  2014年   9136篇
  2013年   10432篇
  2012年   8172篇
  2011年   9036篇
  2010年   7528篇
  2009年   6972篇
  2008年   6973篇
  2007年   7000篇
  2006年   6542篇
  2005年   5857篇
  2004年   4924篇
  2003年   4510篇
  2002年   3378篇
  2001年   3021篇
  2000年   2476篇
  1999年   1963篇
  1998年   1748篇
  1997年   1555篇
  1996年   1379篇
  1995年   1178篇
  1994年   966篇
  1993年   743篇
  1992年   680篇
  1991年   546篇
  1990年   438篇
  1989年   455篇
  1988年   359篇
  1987年   314篇
  1986年   288篇
  1985年   406篇
  1984年   285篇
  1983年   183篇
  1982年   215篇
  1981年   206篇
  1980年   153篇
  1979年   140篇
  1978年   98篇
  1977年   84篇
  1976年   75篇
  1975年   43篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
马瑛  靳学婷 《中国新药杂志》2007,19(11):991-994
目的:运用药物经济学的方法对在我院应用的6种中药注射液进行成本-效果分析。方法:271例急性脑梗死患者依据药物治疗方案不同分为6组,即血塞通组、舒血宁组、苦碟子组、疏血通组、川芎嗪组、丹红组,分别观察疗效,并运用药物经济学的方法进行成本-效果分析。结果:疏血通组的成本为3 419.90元,总有效率最高(91.84%),6组间增量成本-效果最低。因此疏血通组是较为合理、经济的方案。  相似文献   
34.
①目的 了解猪同种原位心脏移植术后早期一氧化氮 (NO)、一氧化氮合酶 (NOS)含量的变化 ,及其与早期缺血再灌注损伤的关系。②方法 建立猪同种原位心脏移植模型。供心在移植前低温保存 (Thomas液 ,4℃ ) 4h ,移植成功心脏复搏后 2h取材。应用组织化学方法测定心肌组织中NO、NOS的含量 ,应用核酸原位末端标记法 (TUNEL)测定心肌细胞凋亡指数 ,作为评价心肌缺血再灌注损伤的指标。以正常心肌及单纯缺血心肌组织作为对照。③结果 移植后心肌组织NO、NOS的含量较缺血组与正常组低 ,差异有显著意义 (F =2 7.2 2 9、16 .2 0 3,q =5 .716~ 6 .4 12 ,P <0 .0 1)。移植组心肌细胞凋亡指数与正常组及缺血组比较明显升高 ,差异有显著性(F =16 3.884 ,q =7.4 82、6 .975 ,P <0 .0 1)。心肌组织NO、NOS含量与心肌细胞凋亡指数呈负相关关系 (r =- 0 .886、- 0 .795 ,P <0 .0 1)。④结论 猪心脏移植后早期心肌缺血再灌注损伤所致的细胞死亡主要表现为心肌细胞凋亡 ;再灌注期间内源性NO、NOS的减少参与了心脏移植后早期缺血再灌注损伤的发生  相似文献   
35.
Abstract. A total of 81 rat kidney grafts, flushed out and cold stored in either Sacks' or University of Wisconsin (UW) solution, were transplanted into hemodiluted (Hct = 30%± 4%) or untreated (Hct = 43%± 3%) recipients. The cold ischemia times (CIT) used were 24 and 36 h. One week after transplantation, the surviving recipients ( n = 67) were contralaterally nephrectomized. The experiment was terminated after a total period of 4 weeks, and the percentage of surviving animals was determined for each treatment. Data was pooled and the results show that grafts cold stored in UW solution were viable to a significantly greater extent and after longer CIT than grafts cold stored in Sacks' solution (47% vs 23%; P < 0. 05). Recipient hemodilution did not improve graft viability (39% vs 32%; NS). Kidneys cold stored for 24 h were viable to a greater extent than kidneys with a CIT of 36 h (50% vs 15%; P < 0. 01).  相似文献   
36.
Biliary obstruction and multiple hepatic abscesses occurred in a patient after ligation of a segmental branch of the right hepatic duct. The patient was successfully managed by transhepatic biliary drainage and balloon dilatation of an internal fistula that developed between the ligated duct and a Roux limb of jejunum. Internal biliary fistulas may be dilated using interventioanl radiologic techniques to permit nonobstructed bile flow. Implications for the nonsurgical treatment' of biliary strictures are discussed.  相似文献   
37.
跳水运动员颈椎损伤的生物力学研究   总被引:1,自引:1,他引:0  
作者通过在新鲜成人颈椎标本上做了椎体静力性负荷和动力性负荷实验,表明颈椎在后伸位应力为前屈位的50%,最大应力位于颈椎4-6,是跳水运动员头颈部入水时引起颈椎致伤的生物力学因素。  相似文献   
38.
AIMS: To investigate the association between estimated glomerular filtration rate (eGFR) and total and cardiovascular mortality in a population-based cohort of diabetic subjects. METHODS: A longitudinal study using a population-based district diabetes register comprising 3288 subjects in South Tees, UK. The eGFR was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Patients were stratified by baseline eGFR into five stages as per the National Kidney Foundation guidelines: Stage 1, eGFR > 90; Stage 2, eGFR 60-89; Stage 3, eGFR 30-59; Stage 4, eGFR 15-29; and Stage 5, eGFR < 15 ml/min per 1.73 m(2). Main outcome was all-cause and cardiovascular mortality between 1 January 1994 and 31 July 2004. RESULTS: At baseline, mean age (58.4 years) differed between groups. Persons with lower eGFR were older (P < 0.001). Thirty-six percent (n = 1193, males 56%) had died by 10 years (cardiovascular cause in 60%). Median follow-up was 10.5 years amounting to 28 342 person years. Stages 4 and 5 (eGFR 相似文献   
39.
兔坐骨神经挤压伤的MRI与SEP对比研究   总被引:3,自引:0,他引:3  
目的:探讨磁共振成像和体感诱发电位以及两者结合在坐骨神经急性挤压伤中的诊断价值。方法:24只兔按钳夹力的不同随机分为A、B两组,左后肢为损伤侧,右后肢为对照侧,建立坐骨神经急性挤压伤模型,于伤后1、2、4、8周行MR扫描,同时行双侧体感诱发电位检查。结果:损伤侧24条神经,有23条MR显示异常,诊断正确率95.8%,假阴性率4.17%(1/24);24条损伤侧坐骨神经,有22条SEP显示异常,诊断正确率91.6%,假阴性率8.3%(2/24)。MRI与SEP对神经损伤的正确诊断率无统计学差异(P>0.05)。MRI与SEP结合起来,24条损伤神经均显示异常,诊断正确率100%。结论:MR与SEP检查可无创、准确地判断神经损伤,两者结合可明显提高神经损伤的正确诊断率,重复性好,可作为神经损伤的较好诊断手段。  相似文献   
40.
With the introduction of more potent immunosuppressive agents, rejection has decreased in simultaneous pancreas/kidney transplant (SPK) recipients. However, as a consequence, opportunistic infections have increased. The purpose of this report is to outline the course of SPK patients who developed polyomavirus-associated nephropathy (PVAN). A retrospective review of 146 consecutive SPK recipients from January 1, 1996 to December 31, 2002 was performed. Immunosuppression, rejection and development of PVAN were reviewed. Nine patients were identified. All received induction with either OKT3 or thymoglobulin. Immunosuppression included tacrolimus/cyclosporine, MMF/azathioprine and sirolimus/prednisone. Two patients were treated for kidney rejection prior to the diagnosis of PVAN. Time to diagnosis was an average of 359.3 days post-transplantation. Immunosuppression was decreased but five ultimately lost function. However, none developed pancreatic abnormalities as demonstrated by normal glucose and amylase. Two underwent renal retransplantation after PVAN diagnosis and both have normal kidney function. PVAN was the leading cause of renal loss in SPK patients in the first 2 years after transplantation and is a serious concern for SPK recipients. The pancreas, however, is spared from evidence of infection, and no pancreatic rejection occurred when immunosuppression was decreased.  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