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   6682篇
  免费   603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
71.
Previous studies have shown that murine anti-CD4 monoclonal antibody, cross-linked by rabbit anti-mouse immunoglobulin, could mediate apoptosis of murine CD4+ lymphocytes when they were stimulated by T cell receptor antibody. In this study, we have shown that the murine anti-CD4 monoclonal antibody, OKT4, can induce apoptosis in human CD4+ T cells stimulated by the recall antigen tuberculin purified protein derivative (PPD) only when cross-linked by rabbit anti-mouse immunoglobulin. The chimeric anti-CD4 monoclonal antibody, cM-T412 whose Fc fragment is human, was able to cause apoptosis without cross-linking by a second antibody. Similarly, abolition of PPD-induced proliferation of peripheral blood mononuclear cells by cM-T412 did not require cross-linking with rabbit anti-human immunoglobulin. Inhibition of proliferation by cM-T412 could be reduced by pre-treating monocytes with heat-aggregated human IgG. This suggested that monocyte Fcγ receptors might be cross-linking the human Fc of cM-T412. Propidium iodide staining together with immunofluorescence showed that the apoptotic cells were indeed CD4+ lymphocytes. It is proposed that during treatment with cM-T412 in autoimmune disease such as rheumatoid arthritis, cM-T412-coated CD4 T cells, when they are subsequently stimulated by the unknown arthritogenic antigen, may undergo apoptotic cell death through cross-linking of cM-T412 on Fey receptor-positive cells within the joint.  相似文献   
72.
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   
73.
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   
74.
Summary Strains of the virus of foot-and-mouth disease obtained from different hosts and tissue cultures were tested in tissue cultures of pig, calf, ox and lamb kidneys for their ability to multiply and produce cytopathogenic effects. It was found that whereas cattle and kidney strains of the virus multiplied well in the cultures with cytopathogenic effect, mouse and egg adapted strains did not multiply or show cytopathogenic effect to the same extent especially in the ox and calf kidneys, and this could be correlated with their behaviour in cattle, pigs and cattle tongue epithelium tissue cultures. With all the strains used it was found possible to produce plaques on pig kidney monolayers, but the size and shape of the plaque varied as well as the relation of plaque titre to the titre in mice. The plaque size and plaque population from different sources were compared, and it was found that the relative number of the different plaque sizes varied with the source of the virus and changed in passage in the different systems. The possible significance of these findings in relation to vaccine preparation and adaptation of the virus is discussed.Part of the work described represents the kidney tissue culture side of experiments on attenuated strains of the virus of foot-and-mouth disease. We are grateful to our colleagues at Pirbright for the supply of virus strains and the results of many cattle, egg and mouse titrations.We would also like to thank MissP. Tremayne-Smitli, Mr.W. Chapman and Mr.D. Maskell for their excellent assistance in this work.  相似文献   
75.
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   
76.
Alcohol use disorders in persons with co-occurring psychiatric disorders are associated with high rates of psy-chosocial instability and poorer treatment outcomes. Thus, assessment of alcohol use and abuse should become an integral part of psychiatric care. Because setf-report-based measures are frequently used, issues of reliability and validity in this population should be critically examined. The purpose of this article is to review and critique the existing empirical literature that has evaluated the psychometric integrity of self- report-based measures in psychiatric settings, and to outline a research agenda that promises to enhance the accuracy of alcohol assessment by persons receiving psychiatric treatment.  相似文献   
77.
James Strachey published his seminal paper on the nature of therapeutic action in 1934 in which he introduced his ideas on the mutative interpretation. He saw interpretation as the cornerstone of the psychoanalytic method. Since then, there has been a great deal of work looking at the essential nature of the interpretation and how it can promote change. By the1960s, Loewald and others were discussing how interpretation needed to incorporate new psychoanalytic thinking, particularly in the area of object relations. As the intersubjectivity of the psychoanalytic encounter gained more prominence, the use of the structural interpretation decreased. The author suggests that there is still need for further work on how interpretation can promote change. Using theoretical ideas and clinical examples, the paper concludes that the mutative interpretation continues to offer something potentially transformative, but that the technique has to take account of relational aspects of the treatment and the developmental issues of the patient. However, the clinician's relationship with the ideas about a mutative interpretation can also affect the clinician's ability to use it to a therapeutic effect.  相似文献   
78.
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   
79.
The prophylactic and therapeutic effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis (CIA) were evaluated in DA rats. Prophylactic treatment with cyclosporin A and cyclophosphamide suppressed the arthritis incidence, clinical inflammation, destructive bone changes, and development of anti-collagen antibody in DA rats subsequently injected with porcine type-II collagen. Therapeutic treatment with cyclosporin A and cyclophosphamide had a definite suppression on established CIA when started 21 days after the initial collagen injection, but the suppression was less marked than that of prophylactic treatment. Gold had no impact on CIA in DA rats when administered either prophylactically or therapeutically.  相似文献   
80.
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