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   3212324篇
  免费   278176篇
  国内免费   13815篇
耳鼻咽喉   44765篇
儿科学   102235篇
妇产科学   83802篇
基础医学   511030篇
口腔科学   86649篇
临床医学   284910篇
内科学   563862篇
皮肤病学   87150篇
神经病学   277619篇
特种医学   128490篇
外国民族医学   374篇
外科学   510112篇
综合类   98374篇
现状与发展   25篇
一般理论   2374篇
预防医学   268249篇
眼科学   73485篇
药学   221501篇
  18篇
中国医学   9096篇
肿瘤学   150195篇
  2021年   49477篇
  2020年   35325篇
  2019年   58427篇
  2018年   71425篇
  2017年   54219篇
  2016年   59866篇
  2015年   74039篇
  2014年   108407篇
  2013年   173950篇
  2012年   93733篇
  2011年   94348篇
  2010年   117432篇
  2009年   121820篇
  2008年   81794篇
  2007年   85089篇
  2006年   95378篇
  2005年   91704篇
  2004年   93211篇
  2003年   83664篇
  2002年   73229篇
  2001年   89138篇
  2000年   81221篇
  1999年   83067篇
  1998年   58201篇
  1997年   56344篇
  1996年   53925篇
  1995年   54690篇
  1994年   49015篇
  1993年   45692篇
  1992年   58403篇
  1991年   55383篇
  1990年   52493篇
  1989年   51790篇
  1988年   48296篇
  1987年   47297篇
  1986年   45303篇
  1985年   45555篇
  1984年   42992篇
  1983年   39736篇
  1982年   39608篇
  1981年   37331篇
  1980年   35297篇
  1979年   34885篇
  1978年   31971篇
  1977年   29404篇
  1976年   27029篇
  1975年   25610篇
  1974年   26171篇
  1973年   25059篇
  1972年   23658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