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   6693篇
  免费   592篇
  国内免费   11篇
耳鼻咽喉   62篇
儿科学   171篇
妇产科学   294篇
基础医学   885篇
口腔科学   50篇
临床医学   1024篇
内科学   1027篇
皮肤病学   168篇
神经病学   506篇
特种医学   136篇
外国民族医学   1篇
外科学   837篇
综合类   151篇
一般理论   12篇
预防医学   822篇
眼科学   55篇
药学   592篇
中国医学   7篇
肿瘤学   496篇
  2023年   23篇
  2022年   50篇
  2021年   109篇
  2020年   56篇
  2019年   115篇
  2018年   136篇
  2017年   106篇
  2016年   138篇
  2015年   143篇
  2014年   209篇
  2013年   326篇
  2012年   473篇
  2011年   458篇
  2010年   280篇
  2009年   244篇
  2008年   442篇
  2007年   434篇
  2006年   405篇
  2005年   393篇
  2004年   390篇
  2003年   336篇
  2002年   306篇
  2001年   145篇
  2000年   97篇
  1999年   108篇
  1998年   66篇
  1997年   54篇
  1996年   55篇
  1995年   62篇
  1994年   40篇
  1993年   51篇
  1992年   101篇
  1991年   84篇
  1990年   62篇
  1989年   80篇
  1988年   57篇
  1987年   51篇
  1986年   42篇
  1985年   61篇
  1984年   64篇
  1983年   46篇
  1982年   35篇
  1981年   30篇
  1980年   26篇
  1979年   35篇
  1978年   24篇
  1977年   23篇
  1976年   19篇
  1974年   26篇
  1973年   23篇
排序方式: 共有7296条查询结果,搜索用时 15 毫秒
31.
The recent cloning of the thyroid peroxidase (TPO) has shown that it is identical to the thyroid microsomal antigen (TMA), a potent antigen involved in autoimmune thyroid disease (ATD), which shares significant sequence homology with myeloperoxidase. The present study shows that autoantibodies (aAb) to the TMA/TPO antigen cross-react with human leucocyte myeloperoxidase, bovine lactoperoxidase and horseradish peroxidase. Cross-reactivity to myeloperoxidase was only apparent by ELISA using reduced and alkylated antigen preparations or by immunoblotting following denaturation with SDS. Sequential absorption of sera on SDS-denatured thyroid microsomes immobilized on Sepharose-4B followed by absorption on native microsomes removed all aAb specificities to TMA/TPO and the three peroxidase preparations, giving compelling evidence on the genuine cross-reactive nature of these aAbs. Sera from different patients contain different qualitative and quantitative specificities of aAb to the TMA/TPO antigen, confirming the polyclonal nature of this autoimmune response.  相似文献   
32.
Our recent data have confirmed that maximum oxygen delivery in racing Thoroughbreds is positively correlated to left ventricular mass measured by echocardiography. A similar, but weaker relationship also exists between left ventricular mass and Timeform performance rating in commercial racehorses. The relationship of the Thoroughbred heart to racing success and the special problems that selective breeding for aerobic capacity have had in this species are reviewed in this article.  相似文献   
33.
Handicapped children may gain considerably from being introduced systematically to musical sounds. The benefit comes not only from enjoyment, but also from promoting intellectual, emotional, and social development. Some children who are severely handicapped intellectually may have great musical talent, such as perfect pitch, and if this is systematically cultivated a key can sometimes be found unlocking the barriers to the child's progress. Some examples are described.

Several years' experience of working as a music therapist with children both normal and handicapped have convinced me that the use of music as an aid to learning is worth further study and research.

  相似文献   
34.
The genetic polymorphisms of the heat shock protein 70 (HSP70) and complement component C4 were investigated in 90 patients with hyperthyroid Graves' disease and 92 normal control subjects. The 8.5-kb PstI HSP70 allele was strongly associated with Graves' disease when compared with controls (P less than 0.001). The presence of the 8.5-kb PstI HSP70 allele was strongly associated with a deletion of the C4A gene in both patients and controls (P less than 0.0003 and P less than 0.00005 respectively). However, in the absence of C4A gene deletion, the frequency of the 8.5-kb PstI HSP70 allele was still significantly higher in patients when compared with controls (P less than 0.04). These results suggest that the HSP70 locus may have an immunological role to play in autoimmune hyperthyroid Graves' disease.  相似文献   
35.
36.
Major salivary gland tumours were studied for the presence of hormone receptors for oestrogen and progesterone. Of the eight salivary gland tumours exhibiting varied histology, none showed high affinity receptors for oestrogen or progesterone. Salivary tissue from four patients with non-neoplastic salivary gland disease was also studied and found not to contain high affinity receptor sites. The absence of hormone receptors in these glands suggests that such tumours are not dependent on endocrine function.  相似文献   
37.
New families of adhesion molecules play a vital role in platelet functions   总被引:4,自引:0,他引:4  
Adhesion molecules play a crucial part in cell-matrix and in cell-cell interactions. These interactions, which are essential to the body's defense processes, involve adhesion molecules belonging to different families: integrins, immunoglobulins and selectins. Integrins are expressed by a large number of tissues, whereas other adhesion molecule families are restricted to a small number of cell types. A recent symposium dealt with the recruitment of circulating platelets at specific sites, their adhesion to extracellular matrix components and their activation by agonists leading to aggregation or attachment to other cells. These events, supporting hemostasis and thrombosis, involve integrins, selectins and other adhesion molecules. This report focuses on newly reported integrins (GPIa, GPIc, GPIIa), selectins (GMP-140) and GPIIIb, previously known as 'minor' surface oriented platelet glycoproteins. Major membrane glycoproteins such as GPIIb-IIIa (an integrin) and GPIb, which also play a vital role in platelet functions, have been extensively reviewed elsewhere.  相似文献   
38.
Interleukin 17 modulates the immune response to vaccinia virus infection   总被引:2,自引:0,他引:2  
Interleukin 17 (IL-17) is a newly identified cytokine that has a homolog in herpesvirus saimiri. We inserted murine IL-17 into vaccinia virus to study the role of IL-17 in viral infection. Vaccinia virus expressing IL-17 (vv-IL17) and its parental control virus (vv-pRB) grew to similar titers in vitro; however, vv-IL17 was more virulent in mice with a threefold lower LD(50) than for vv-pRB, and mean time to death of 2.8 days versus 4.5 days. Mice infected with vv-IL17 had higher titers of virus in the ovaries (P < 0.02) and showed a decrease in NK cell cytotoxicity (P < 0.02) on day 3 after infection. No significant difference was found in CTL activity. In addition, a significant decrease in IgG2a (P < 0.01) and increases in IgG1, IgG3, and IgA (P < 0.03) vaccinia virus-specific antibody titers were observed in mice infected with vv-IL17 versus vv-pRB, suggesting a Th-2-like response to infection. These data indicate that IL-17 modulates the immune response during virus infection.  相似文献   
39.
Recently, evidence has accumulated for the role of neurotrophic processes in mood disorders. Neurotrophins operate on receptors, one of which is the p75 neurotrophin receptor (p75(NTR)). We examined three p75(NTR) markers at the p75(NTR) gene, including a missense polymorphism that changes serine to leucine (S205L), for association with suicide attempt (SA) in 203 childhood-onset mood disorder (COMD) cases. There was no difference between COMD suicide attempters and COMD non-attempters with logistic regression models for any of the three markers. We also compared the three polymorphisms between 192 COMD cases and 192 matched healthy controls and found no significant differences between COMD and healthy controls. Our results do not support an association of the p75(NTR) S205L polymorphism with risk for COMD or SA in COMD.  相似文献   
40.
Genetic linkage analysis has been instrumental in mapping thegene for X-linked agammaglobulinemia (XLA) to the proximal longarm of the human X chromosome, to Xq22. Due to the relativerarity of this disease the localization of the gene within Xq22has remained imprecise. We have investigated twenty-nine familiesaffected by XLA and have found no recombinants with the DXS178locus in over 30 informative meioses. DXS178 is now the mostreliable and informative locus for use in pre-natal diagnosisand carrier detection of XLA. In addition, we have identifiednew closely linked proximal and distal flanking markers forXLA, DXS442 and DXS101, respectively. These loci are separatedby 2cM, considerably reducing the extent of DNA within whichthe XLA locus can be contained. This will open up the way formore directed positional cloning efforts for the isolation ofthe XLA gene.  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