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   3094272篇
  免费   271951篇
  国内免费   13546篇
耳鼻咽喉   43568篇
儿科学   99112篇
妇产科学   81354篇
基础医学   496848篇
口腔科学   83996篇
临床医学   273569篇
内科学   540303篇
皮肤病学   85611篇
神经病学   266878篇
特种医学   124906篇
外国民族医学   361篇
外科学   492771篇
综合类   96407篇
现状与发展   23篇
一般理论   2166篇
预防医学   256534篇
眼科学   70736篇
药学   212712篇
  17篇
中国医学   8804篇
肿瘤学   143093篇
  2021年   49106篇
  2020年   34848篇
  2019年   57784篇
  2018年   70206篇
  2017年   53186篇
  2016年   58745篇
  2015年   73045篇
  2014年   107084篇
  2013年   172137篇
  2012年   83956篇
  2011年   82934篇
  2010年   114134篇
  2009年   119450篇
  2008年   70834篇
  2007年   72834篇
  2006年   83923篇
  2005年   79910篇
  2004年   81848篇
  2003年   73076篇
  2002年   62787篇
  2001年   88508篇
  2000年   80692篇
  1999年   82521篇
  1998年   57611篇
  1997年   55945篇
  1996年   53567篇
  1995年   54348篇
  1994年   48662篇
  1993年   45443篇
  1992年   58125篇
  1991年   55121篇
  1990年   52223篇
  1989年   51588篇
  1988年   48071篇
  1987年   47060篇
  1986年   45103篇
  1985年   45319篇
  1984年   42773篇
  1983年   39491篇
  1982年   39383篇
  1981年   37139篇
  1980年   35085篇
  1979年   34732篇
  1978年   31816篇
  1977年   29259篇
  1976年   26901篇
  1975年   25472篇
  1974年   26045篇
  1973年   24939篇
  1972年   23562篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
Many environmental risk factors for hepatobiliary cancers are known but whether they are associated with specific cancer types is unclear. We present here a novel approach of assessing standardized incidence ratios (SIRs) of previously diagnosed comorbidities for hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cholangiocarcinoma (CCA) and ampullary cancer. The 13 comorbidities included alcohol and nonalcohol related liver disease, chronic obstructive pulmonary disease, gallstone disease, viral and other kinds of hepatitis, infection of bile ducts, hepatic and other autoimmune diseases, obesity and diabetes. Patients were identified from the Swedish Inpatient Register from 1987 to 2018, and their cancers were followed from 1997 onwards. SIRs for HCC were 80 to 100 in men and women diagnosed with hepatitis C virus and they were also >10 in patients diagnosed with hepatitis B virus, other kind of hepatitis, hepatic autoimmune disease and nonalcohol related liver disease. Many of these risks, as well as alcohol related liver disease, were either specific to HCC or were shared with intrahepatic CCA. For GBC, CCA and ampullary cancer infection of bile ducts was the main risk factor. Gallstone disease, nonhepatic autoimmune diseases and diabetes were associated with all hepatobiliary cancers. The limitations of the study include inability to cover some rare risk factors and limited follow-up time. Many of the considered comorbidities are characterized by chronic inflammation and/or overt immune disturbance in autoimmune diseases. The results suggest that local chronic inflammation and a related immune disturbance is the carcinogenic trigger for all these cancers.  相似文献   
2.
3.
4.
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.  相似文献   
5.
6.
7.
8.
9.
10.
Aristodemou  E.  Retzepi  M.  Calciolari  E.  Donos  N. 《Clinical oral investigations》2022,26(8):5223-5235
Clinical Oral Investigations - To evaluate the effect of membrane occlusiveness and experimental diabetes on early and late healing following guided bone regeneration. A total of 30 Wistar rats...  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