全文获取类型
收费全文 | 37931篇 |
免费 | 2636篇 |
国内免费 | 110篇 |
专业分类
耳鼻咽喉 | 581篇 |
儿科学 | 916篇 |
妇产科学 | 502篇 |
基础医学 | 4781篇 |
口腔科学 | 595篇 |
临床医学 | 3855篇 |
内科学 | 8594篇 |
皮肤病学 | 238篇 |
神经病学 | 3743篇 |
特种医学 | 1531篇 |
外科学 | 6369篇 |
综合类 | 382篇 |
一般理论 | 78篇 |
预防医学 | 2920篇 |
眼科学 | 568篇 |
药学 | 2304篇 |
中国医学 | 32篇 |
肿瘤学 | 2688篇 |
出版年
2023年 | 244篇 |
2022年 | 416篇 |
2021年 | 1012篇 |
2020年 | 555篇 |
2019年 | 933篇 |
2018年 | 1095篇 |
2017年 | 768篇 |
2016年 | 868篇 |
2015年 | 985篇 |
2014年 | 1385篇 |
2013年 | 1735篇 |
2012年 | 2814篇 |
2011年 | 2854篇 |
2010年 | 1612篇 |
2009年 | 1315篇 |
2008年 | 2454篇 |
2007年 | 2544篇 |
2006年 | 2431篇 |
2005年 | 2404篇 |
2004年 | 2187篇 |
2003年 | 2058篇 |
2002年 | 1969篇 |
2001年 | 420篇 |
2000年 | 328篇 |
1999年 | 382篇 |
1998年 | 393篇 |
1997年 | 315篇 |
1996年 | 279篇 |
1995年 | 276篇 |
1994年 | 218篇 |
1993年 | 210篇 |
1992年 | 247篇 |
1991年 | 267篇 |
1990年 | 228篇 |
1989年 | 202篇 |
1988年 | 166篇 |
1987年 | 170篇 |
1986年 | 154篇 |
1985年 | 154篇 |
1984年 | 174篇 |
1983年 | 150篇 |
1982年 | 148篇 |
1981年 | 136篇 |
1980年 | 110篇 |
1979年 | 85篇 |
1978年 | 86篇 |
1977年 | 67篇 |
1976年 | 59篇 |
1974年 | 53篇 |
1973年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
MD MS Gregory L Larkin PhD John Moskop MD FACEP Arthur Sanders MD JD FACEP Arthur Derse 《Annals of emergency medicine》1994,24(6)
Confidentiality is a promise rooted in tradition, law andmedical ethics. Emergency physicians treat a variety of patients to whom confidentiality is of vital importance: employees, celebrities, victims of violence or disaster, minors, students, criminals, drug abusers, and patients with STDs. EDs should develop methods of ensuring confidentiality for all patients.34Although confidentiality is an important principle thatshould be respected and guarded, it is not absolute. Various laws mandate disclosure of certain patient information; in addition, an overriding moral duty may occasionally require, a breach of confidentiality. As Beauchamp and Childress noted, “the therapeutic role may sometimes have to yield to ones role as citizen and as protector of the interests of others”.19 In general, however, circumstances requiring a breach of confidentiality are rare. 相似文献
132.
133.
K A Knox M Finney A E Milner C D Gregory M J Wakelam R H Michell J Gordon 《International journal of cancer. Journal international du cancer》1992,52(6):959-966
Spontaneous apoptosis in germinal-centre (GC) B cells can be prevented by treatment with anti-immunoglobulin (Ig). By contrast, susceptible group-I Burkitt lymphoma (BL) cells can be driven to apoptosis by anti-Ig. The second-messenger pathways involved in the regulation of apoptosis in GC B lymphocytes and in BL cell lines were studied using pharmacological agonists or inhibitors of intracellular calcium ([Ca2+]i) and protein kinase C (PKC). Anti-Ig was found to mobilize Ca2+ in group-I cells. Pre-incubation with the Ca2+ chelator EGTA partially reduced apoptosis induced by anti-Ig or by Ca2+ ionophore in group-I BL cells. Activation of PKC with phorbol ester reduced such Ca(2+)-driven programmed cell death (PCD) to control levels of apoptosis. Apoptosis in group-I BL cell lines could also be triggered by the kinase inhibitors staurosporine and Ro-31-8220 at concentrations selective for PKC activity. Expression of the bcl-2 protein in BL group-I cells following gene transfer affords protection from apoptosis induced by ionomycin or anti-Ig. In the present study, bcl-2 was additionally found to protect from apoptosis driven by staurosporine. The high levels of spontaneous apoptosis exhibited by normal GC B cells were reduced, but not abrogated, by co-culture with phorbol ester. These results indicate that, in group-I BL cells, imbalance in the phosphoinositide pathway of signalling, in favour of [Ca2+]i and away from PKC, results in apoptosis: constitutive phosphorylation of key proteins by PKC may therefore suppress apoptosis in BL as well as in GC B cells. 相似文献
134.
cAMP production was investigated in retinal pigment epithelium (RPE) cells isolated from normal rats and from rats with an inherited retinal dystrophy (Rdy/p+). In normal RPE cells, 5'-[N-Ethylcarboxamido]-adenosine (A2 receptors) produced a fivefold increase in the level of cyclic adenosine monophosphate (cAMP) over basal levels. However, only a onefold increase in cAMP was observed in dystrophic cells. cAMP production by prostaglandins E1 and E2 (prostaglandin receptors) in dystrophic RPE cells was only 29-38% of the level observed in normal cells. Direct stimulation of adenylyl cyclase by 10 mumol/l forskolin increased cAMP levels in normal RPE cells by 90 fold over basal, but only by sixfold in the dystrophic cells. These data suggest there may be a defect in the adenylyl cyclase signaling pathway in dystrophic RPE cells. 相似文献
135.
136.
Thomas Patrick S. Jr; Fraley Gregory S.; Damian Vincent; Woodke Lillie B.; Zapata Francisco; Sopher Bryce L.; Plymate Stephen R.; La Spada Albert R. 《Human molecular genetics》2006,15(19):2972
Human Molecular 相似文献
137.
Summary: B-cell development is a highly ordered multistep process dependent upon signals generated by the pre-B and B-cell antigen receptor (BCR). BCR signals drive maturation of the B cell by integrating a number of parallel and sequential biological processes that result in generation of fully immunocompetent B cells. Among these biological processes are positive selection through several developmental checkpoints, negative selection of potentially self-reactive B cells, and activation of the mature B cell. In addition, recent studies have shown that developing and mature B cells rely on the constant activity of the BCR for their continued survival. Ligand (antigen)-dependent and -independent mechanisms of BCR signaling have been proposed, but their specific contributions to B-cell maturation and differentiation in the bone marrow and periphery are not completely clear. We discuss here a model, whereby ligand-independent basal BCR activity would be sufficient to trigger B-cell development through to the mature stage. However, long-term survival and formation of specific mature B-cell populations may be dependent on ligand–receptor interactions. 相似文献
138.
139.
140.