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   7201篇
  免费   460篇
  国内免费   52篇
耳鼻咽喉   96篇
儿科学   123篇
妇产科学   150篇
基础医学   1112篇
口腔科学   238篇
临床医学   551篇
内科学   1764篇
皮肤病学   250篇
神经病学   623篇
特种医学   201篇
外科学   863篇
综合类   57篇
一般理论   1篇
预防医学   482篇
眼科学   98篇
药学   560篇
中国医学   52篇
肿瘤学   492篇
  2023年   51篇
  2022年   129篇
  2021年   317篇
  2020年   144篇
  2019年   189篇
  2018年   241篇
  2017年   177篇
  2016年   174篇
  2015年   201篇
  2014年   296篇
  2013年   356篇
  2012年   572篇
  2011年   555篇
  2010年   303篇
  2009年   286篇
  2008年   488篇
  2007年   464篇
  2006年   430篇
  2005年   404篇
  2004年   397篇
  2003年   314篇
  2002年   341篇
  2001年   75篇
  2000年   57篇
  1999年   54篇
  1998年   43篇
  1997年   46篇
  1996年   49篇
  1995年   36篇
  1994年   28篇
  1993年   34篇
  1992年   42篇
  1991年   40篇
  1990年   32篇
  1989年   25篇
  1988年   29篇
  1987年   16篇
  1986年   13篇
  1985年   20篇
  1984年   31篇
  1983年   27篇
  1982年   16篇
  1981年   22篇
  1979年   15篇
  1978年   15篇
  1977年   16篇
  1974年   9篇
  1973年   14篇
  1972年   9篇
  1966年   8篇
排序方式: 共有7713条查询结果,搜索用时 15 毫秒
1.
2.
3.
We report on a 3‐year‐old girl with a microvesicular generalized rash in whom primary infection by parvovirus B19 was demonstrated by seroconversion. To our knowledge, this is the first instance of an eruption arising from parvovirus B19 with this peculiar clinical pattern.  相似文献   
4.
5.
Clinical decisions are often made with incomplete information, yet patient care decisions are made every day. Patients vary clinically, uncertainty exists in diagnostic and prognostic information, and many preventive and treatment alternatives have not been formally assessed for their effectiveness. Because scientific information will never answer all clinical questions, clinical decisions are partially based on probabilistic information.
This paper describes how to apply clinical decision making to diagnosing and managing dental caries and periodontal diseases. By using explicit information to quantify probabilities and outcomes, clinical decision making analyzes decisions made under uncertain conditions and the uncertain impact of clinical information.
Clinical decision making incorporates concepts for preventing, diagnosing and treating dental caries and periodontal diseases: risk assessment, evidence-based dentistry, and multiple oral health outcomes. This information can serve as a tool for clinicians to augment clinical judgment and expertise.  相似文献   
6.
7.
8.
Mice pretreated with Bacillus megaterium ATCC 33085 grown on TSA medium developed a significant increase in primary antibody response to SRBC. Conversely, pretreatment with a spore suspension harvested from nutrient Agar medium decreased this antibody response. A suspension of organisms grown on a defined, phosphorus-deficient medium (P-Medium) had no effect. Otherwise, only the spore suspension was able to enhance the contact sensitivity to dinitrofluorobenzene. Peritoneal leucocyte numbers were increased by inoculation with both TSA-cultured bacteria and the spore suspension, but not by P-Medium-cultured bacteria. Administration of both the spore suspension and P-Medium-cultured bacteria decreased the in vitro phagocytosis by peritoneal adherent cells. These immunomodulator properties are discussed in relation to characteristics of the strain tested.  相似文献   
9.
A middle-down LC/MS approach, for the rapid quantitation and characterization of site-specific methionine oxidation in a recombinant monoclonal IgG1 molecule, is described. An IgG1 antibody was digested with endoprotease LysC under limited proteolytic conditions to produce two major components; an antigen binding fragment (Fab) and a crystallizable fraction (Fc). These fractions were then reduced to produce three major species; light chain (LC), Fc/2 which is the C terminal region of the heavy chain (HC) and the N-terminal heavy chain region (Fd). These three fragments were separated by reversed-phase HPLC using a diphenyl column. The diphenyl column resolved site-specific methionine oxidation in all three subunits. Middle- down N-terminal sequencing with a LCT premier mass spectrometer was used to identify the sites of oxidation in the LC. Sites of oxidation in the Fc/2 were identified using middle-down collision-induced dissociation (CID) on a Qtof premier. This method allowed for the rapid quantitation and identification of oxidation on each methionine residue in an IgG1 molecule.  相似文献   
10.
We have constructed a new capsid-modified adenovirus (Ad) vector that specifically replicates in tumor cells and expresses TNF-related apoptosis-inducing ligand (TRAIL). The Ad capsid contains short-shafted fibers derived from Ad serotype 35, which allow for efficient infection of malignant tumor cells, and largely avoids innate toxicity after intravenous application. Replication-dependent homologous recombination in Ad genomes was used to achieve tumor-specific expression of Ad E1a (to mediate viral replication) and TRAIL (to mediate apoptosis and enhance release of progeny virus from infected cells). We demonstrated that our oncolytic vector (Ad5/35.IR-E1A/TRAIL) induced apoptosis in human tumor cell lines derived from colorectal, lung, prostate, and liver cancer. Both in vitro and in vivo tumor models showed efficient intratumoral spread of this vector. In a model for metastatic colon cancer, tail vein infusion of Ad5/35.IR-E1A/TRAIL resulted in elimination of preestablished liver metastases. Intravenous injection of this vector caused a transient elevation of serum glutamic pyruvic transaminase in tumor-bearing mice, which we attributed to factors released from apoptotic tumor cells. Liver histology analyzed at day 14 after virus injection did not show signs of hepatocellular damage. This new oncolytic vector represents a potentially efficient means for gene therapy of metastatic cancer.  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