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   15201篇
  免费   1045篇
  国内免费   152篇
耳鼻咽喉   200篇
儿科学   350篇
妇产科学   172篇
基础医学   1903篇
口腔科学   232篇
临床医学   1247篇
内科学   3958篇
皮肤病学   306篇
神经病学   1043篇
特种医学   627篇
外科学   2178篇
综合类   202篇
一般理论   21篇
预防医学   1086篇
眼科学   363篇
药学   918篇
中国医学   60篇
肿瘤学   1532篇
  2023年   92篇
  2022年   157篇
  2021年   344篇
  2020年   236篇
  2019年   332篇
  2018年   376篇
  2017年   353篇
  2016年   396篇
  2015年   441篇
  2014年   556篇
  2013年   693篇
  2012年   1128篇
  2011年   1087篇
  2010年   669篇
  2009年   525篇
  2008年   1011篇
  2007年   1110篇
  2006年   982篇
  2005年   1042篇
  2004年   895篇
  2003年   971篇
  2002年   907篇
  2001年   147篇
  2000年   127篇
  1999年   140篇
  1998年   174篇
  1997年   182篇
  1996年   145篇
  1995年   135篇
  1994年   93篇
  1993年   81篇
  1992年   78篇
  1991年   63篇
  1990年   58篇
  1989年   49篇
  1988年   43篇
  1987年   37篇
  1986年   29篇
  1985年   39篇
  1984年   39篇
  1983年   38篇
  1982年   37篇
  1981年   29篇
  1980年   31篇
  1979年   24篇
  1978年   24篇
  1977年   31篇
  1976年   18篇
  1973年   19篇
  1966年   18篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
61.
Postsynaptic dopamine (DA) receptor sensitivity was assessed during abstinence in 15 male patients with alcohol dependence. The DA receptor sensitivity was evaluated using growth hormone (GH) responses to the DA receptor agonist apomorphine (0.18-0.24 mg intravenously). The patients were cared for in an alcoholism treatment unit for the 2 months prior to the investigation. They were carefully controlled for sobriety during this period. Thirteen healthy men were used as controls. The maximum GH responses to apomorphine were significantly reduced in patients compared with those in the control group. The patients had a significantly higher proportion of blunted GH responses. The findings suggest reduced postsynaptic DA, possibly D2, receptor sensitivity in abstinent alcoholics. The question whether this abnormal DA receptor status is genetically determined or acquired after long-term alcohol consumption remains to be addressed.  相似文献   
62.
63.
Thrombotic microangiopathy (TMA) may develop after living donor liver transplantation (LDLT), but the mechanism is not fully understood. We retrospectively analyzed all patients undergoing LDLT at our center, including TMA patients, to elucidate the clinical characteristics and presentation and to determine which patients have a higher risk of occurrence of TMA. In all, 57 adult patients were reviewed after LDLT at our institution. TMA was diagnosed by sudden and severe thrombocytopenia, followed by hemolytic anemia with fractionated erythrocytes in the blood smear. Clinical features were compared between the TMA group and the non-TMA group. Of the 57 patients, 4 were diagnosed with posttransplantation TMA. ABO blood group (ABO)-incompatibility, cyclophosphamide (CPA), and recipient blood group (type O) were closely correlated with the occurrence of TMA. Thrombocytopenia appeared 1 to 5 days before hemolytic anemia. Coagulative function markers stayed at the same level after TMA, while marked elevation was shown in fibrinolytic function markers such as plasminogen activator inhibitor type 1 (PAI-1). TMA occurred at a higher prevalence in ABO-incompatible graft recipients. Additional factors associated with ABO-incompatible transplantation, such as an overdose of immunosuppressants, may affect the likelihood of TMA. Sudden and severe thrombocytopenia presented before hemolytic anemia and the serum levels of PAI-1 correlated well with the clinical course of TMA. In conclusion, early recognition of thrombocytopenia and elevation of PAI-1 is crucial to diagnose TMA especially in ABO-incompatible LDLT.  相似文献   
64.
PURPOSE: To evaluate the treatment results of low-dose-rate (LDR) and high-dose-rate (HDR) interstitial brachytherapy (ISBT) for T3 mobile tongue cancer. MATERIAL AND METHODS: Between 1974 and 1992, 61 patients with T3 mobile tongue cancer were treated with LDR ISBT using (192)Ir hairpins with or without single pins. In addition, between 1991 and 1999, 14 patients were treated with HDR ISBT. For nine patients treated with ISBT alone, the total dose was 59-94 Gy (median 72 Gy) within one week in LDR ISBT and 60 Gy/10 fractions/5 days in HDR ISBT. For 66 patients treated with a combination therapy of external beam radiotherapy (EBRT) and ISBT, the total dose was 12.5-60 Gy (median 30 Gy) of EBRT and 50-112 Gy (median 68 Gy) within 1 week in LDR ISBT or 32-60 Gy (median 48 Gy)/8-10 fractions/5-7 days in HDR ISBT. RESULTS: The 2- and 3-year local control rates of all patients were both 68%. The 2- and 3-year local control rates of patients treated with LDR ISBT were both 67%, and those with HDR ISBT were both 71%. The local control rate of patients treated with HDR ISBT was similar to those with LDR ISBT. CONCLUSIONS: ISBT for T3 mobile tongue cancer is effective and acceptable. The treatment result of HDR ISBT is almost similar to that of LDR ISBT for T3 mobile tongue cancer.  相似文献   
65.
66.
Background: Opioids are commonly used in conjunction with sedative drugs to provide anesthesia. Previous studies have shown that opioids reduce the clinical requirements of sedatives needed to provide adequate anesthesia. Processed electroencephalographic parameters, such as the Bispectral Index (BIS; Aspect Medical Systems, Newton, MA) and Auditory Evoked Potential Index (AAI; Alaris Medical Systems, San Diego, CA), can be used intraoperatively to assess the depth of sedation. The aim of this study was to characterize how the addition of opioids sufficient to change the clinical level of sedation influenced the BIS and AAI.

Methods: Twenty-four adult volunteers received a target-controlled infusion of remifentanil (0-15 ng/ml) and inhaled sevoflurane (0-6 vol%) at various target concentration pairs. After reaching pseudo-steady state drug levels, the modified Observer's Assessment of Alertness/Sedation score, BIS, and AAI were measured at each target concentration pair. Response surface pharmacodynamic interaction models were built using the pooled data for each pharmacodynamic endpoint.

Results: Response surface models adequately characterized all pharmacodynamic endpoints. Despite the fact that sevoflurane-remifentanil interactions were strongly synergistic for clinical sedation, BIS and AAI were minimally affected by the addition of remifentanil to sevoflurane anesthetics.  相似文献   

67.
68.
69.
During a survey of the parasite fauna of the euryhaline notothenioid fish Eleginops maclovinus (Cuvier) caught in brackish water creeks in the Falkland Islands, small white cysts were observed in the mesenteries and on the surfaces of the visceral organs and heart. On dissection these proved to be plasmodia of a species of the myxosporean genus Henneguya. This is the first record of a member of this genus from a marine or euryhaline fish in the south-west Atlantic. A comparison of the spore of our species with other species in the genus convinced us that our species is new. This paper describes it as Henneguya shackletoni sp. nov. after the Shackleton Fund which funded the study.  相似文献   
70.
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