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   3950797篇
  免费   324247篇
  国内免费   15196篇
耳鼻咽喉   56115篇
儿科学   123990篇
妇产科学   107074篇
基础医学   603257篇
口腔科学   111775篇
临床医学   348400篇
内科学   709942篇
皮肤病学   102002篇
神经病学   332682篇
特种医学   159507篇
外国民族医学   767篇
外科学   619776篇
综合类   118919篇
现状与发展   24篇
一般理论   2411篇
预防医学   317027篇
眼科学   92051篇
药学   279943篇
  18篇
中国医学   11067篇
肿瘤学   193493篇
  2021年   49502篇
  2020年   35325篇
  2019年   58385篇
  2018年   72196篇
  2017年   54957篇
  2016年   60921篇
  2015年   74551篇
  2014年   108829篇
  2013年   174176篇
  2012年   105231篇
  2011年   107244篇
  2010年   120134篇
  2009年   123920篇
  2008年   95270篇
  2007年   101116篇
  2006年   110680篇
  2005年   106323篇
  2004年   107899篇
  2003年   98773篇
  2002年   88769篇
  2001年   136932篇
  2000年   131141篇
  1999年   123041篇
  1998年   62555篇
  1997年   59535篇
  1996年   57069篇
  1995年   57704篇
  1994年   52076篇
  1993年   48447篇
  1992年   90240篇
  1991年   86275篇
  1990年   82971篇
  1989年   81512篇
  1988年   76071篇
  1987年   74369篇
  1986年   71361篇
  1985年   70064篇
  1984年   60031篇
  1983年   53547篇
  1982年   45248篇
  1981年   42155篇
  1980年   39802篇
  1979年   52371篇
  1978年   43213篇
  1977年   38863篇
  1976年   35557篇
  1975年   36069篇
  1974年   39491篇
  1973年   37885篇
  1972年   36141篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
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