全文获取类型
收费全文 | 7714篇 |
免费 | 558篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 312篇 |
妇产科学 | 122篇 |
基础医学 | 951篇 |
口腔科学 | 95篇 |
临床医学 | 743篇 |
内科学 | 1646篇 |
皮肤病学 | 103篇 |
神经病学 | 807篇 |
特种医学 | 351篇 |
外科学 | 1223篇 |
综合类 | 38篇 |
预防医学 | 536篇 |
眼科学 | 118篇 |
药学 | 572篇 |
中国医学 | 14篇 |
肿瘤学 | 643篇 |
出版年
2024年 | 14篇 |
2023年 | 95篇 |
2022年 | 122篇 |
2021年 | 204篇 |
2020年 | 169篇 |
2019年 | 214篇 |
2018年 | 263篇 |
2017年 | 234篇 |
2016年 | 215篇 |
2015年 | 257篇 |
2014年 | 331篇 |
2013年 | 431篇 |
2012年 | 608篇 |
2011年 | 622篇 |
2010年 | 321篇 |
2009年 | 288篇 |
2008年 | 489篇 |
2007年 | 502篇 |
2006年 | 511篇 |
2005年 | 417篇 |
2004年 | 414篇 |
2003年 | 374篇 |
2002年 | 373篇 |
2001年 | 58篇 |
2000年 | 40篇 |
1999年 | 60篇 |
1998年 | 71篇 |
1997年 | 59篇 |
1996年 | 58篇 |
1995年 | 50篇 |
1994年 | 40篇 |
1993年 | 44篇 |
1992年 | 27篇 |
1991年 | 29篇 |
1990年 | 22篇 |
1989年 | 22篇 |
1988年 | 17篇 |
1987年 | 19篇 |
1986年 | 23篇 |
1985年 | 20篇 |
1984年 | 13篇 |
1983年 | 31篇 |
1982年 | 19篇 |
1981年 | 21篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1975年 | 11篇 |
1972年 | 7篇 |
1967年 | 7篇 |
排序方式: 共有8323条查询结果,搜索用时 15 毫秒
31.
Henrik Husted S ren Overgaard Jens Ole Laursen Klaus Hinds Lise N rrekjaer Hansen Harald M. Knudsen Niels B. Mossing 《Acta orthopaedica》1996,67(5):421-423
During the 10-year period 1981-1990, 1, 199 patients in the county of South Jutland, Denmark, had 1, 477 primary total hip arthroplasties (THA) performed because of primary arthrosis (OA).
The patients were followed until the end of 1994, with a mean follow-up of 5.6 (0-14) years. Bilateral operations were performed on 356 patients, whereas 248 patients had died with only 1 THA.
The cumulated risk of replacement of the contralateral hip was approximately 0.15 1 year after replacement of the first hip, 0.20 after 2 years, 0.29 after 5 years and 0.47 after 10 years, respectively.
During the follow-up period, the demand for a THA of the contralateral hip continued to be approximately 15 times higher than in the general population. 相似文献
The patients were followed until the end of 1994, with a mean follow-up of 5.6 (0-14) years. Bilateral operations were performed on 356 patients, whereas 248 patients had died with only 1 THA.
The cumulated risk of replacement of the contralateral hip was approximately 0.15 1 year after replacement of the first hip, 0.20 after 2 years, 0.29 after 5 years and 0.47 after 10 years, respectively.
During the follow-up period, the demand for a THA of the contralateral hip continued to be approximately 15 times higher than in the general population. 相似文献
32.
Erik A. Richter Bente Sonne Kari J. Mikines Thorkil Ploug Henrik Galbo 《European journal of applied physiology》1984,52(3):346-350
Summary We have previously found that during exercise net muscle glycogen breakdown is impaired in adrenodemedullated rats, as compared with controls. The present study was carried out to elucidate whether, in rats with deficiencies of the sympatho-adrenal system, diminished exercise-induced glycogenolysis in skeletal muscle was accompanied by increased breakdown of triglyceride and/or protein. Thus, the effect of exhausting swimming and of running on concentrations of glycogen, protein, and triglyceride in skeletal muscle and liver were studied in rats with and without deficiencies of the sympatho-adrenal system. In control rats, both swimming and running decreased the concentration of glycogen in fast-twitch red and slow-twitch red muscle whereas concentrations of protein and triglyceride did not decrease. In the liver, swimming depleted glycogen stores but protein and triglyceride concentrations did not decrease. In exercising rats, muscle glycogen breakdown was impaired by adrenodemedullation and restored by infusion of epinephrine. However, impaired glycogen breakdown during exercise was not accompanied by a significant net breakdown of protein or triglyceride. Surgical sympathectomy of the muscles did not influence muscle substrate concentrations. The results indicate that when glycogenolysis in exercising muscle is impeded by adrenodemedullation no compensatory increase in breakdown of triglyceride and protein in muscle or liver takes place. Thus, indirect evidence suggests that, in exercising adrenodemedullated rats, fatty acids from adipose tissue were burnt instead of muscle glycogen. 相似文献
33.
34.
Henrik Aggerbeck Bent Nørgaard-Pedersen Iver Heron 《Journal of immunological methods》1996,190(2):171-183
A dual, double antigen, time-resolved fluorescence immunoassay (DELFIA) for the simultaneous detection and quantitation of diphtheria (D) and tetanus (T) antibodies in sera has been developed. In the double antigen format one arm of the antibody binds to antigen coated microtitre wells and the other arm binds to labelled antigen to provide a fluorescent signal. This assay was found to be functionally specific for IgG antibodies and showed a good correlation with established toxin neutralization assays. Furthermore, the double antigen set-up was species independent, permitting the direct use of existing international references of animal origin to measure protective antibody levels in humans in international units (IU/ml). The detection limit corresponded to 0.0003 IU/ml with Eu3+-labelled toxoids and to 0.0035 IU/ml using Sm3+-labelled toxoids. The assay was fast with a high capacity making it a suitable method for serological surveillance studies. 相似文献
35.
Antibody-antigen cross-reactions were examined with sera from patients with Escherichia coli O157 infection and lipopolysaccharide (LPS) purified from a range of enterohaemorrhagic E. coli (EHEC) including those belonging to serogroups O26, O103, O111, O145 and O157. Six of 10 patients infected with an O157 EHEC produced serum antibodies that cross-reacted with common LPS-core epitopes, which were expressed by 23 of 33 strains of EHEC examined. These common LPS-core epitopes were also present on strains of E. coli O26 which did not produce verocytotoxin. These cross-reacting antibodies did not influence the basic immunoblotting procedures used for the routine serodiagnosis of infections with E. coli O157. 相似文献
36.
Henrik Husby Borghild Roald Rune Schjetlein Britt-Igjerd Nesheim Kåre Berg 《Clinical genetics》1996,50(1):47-49
We report a family with two cases of severe pre-eclampsia/eclampsia in which very high levels of Lp(a) lipoprotein were found. The serum level of Lp(a) lipoprotein is genetically determined and the Lp(a) apolipoprotein has a close homology to plasminogen. Very high levels of Lp(a) lipoprotein might interfere with the fibrinolytic/thrombolytic process in man. A previous report suggested that a high maternal serum Lp(a) lipoprotein level can cause fetal growth retardation, and it is proposed that very high levels might lead to increased deposition of fibrin in the uterine spiral arteries in pregnancy, which is central in the pathogenesis of pre-eclampsia. If confirmed, a very high Lp(a) lipoprotein level could be one risk factor for pre-eclampsia that is genetically determined. 相似文献
37.
38.
Henrik Toft-Hansen Alicia A Babcock Jason M Millward Trevor Owens 《Journal of neuroinflammation》2007,4(1):24
Background
Matrix metalloproteinases (MMPs) are thought to mediate cellular infiltration in central nervous system (CNS) inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (MT-MMPs). Leukocyte infiltration is an integral part of the pathogenesis of autoimmune inflammation in the CNS, as occurs in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE), as well as in the response to brain trauma and injury. We have previously shown that gene expression of the majority of MMPs was upregulated in the spinal cord of SJL mice with severe EAE induced by adoptive transfer of myelin basic protein-reactive T cells, whereas four of the six MT-MMPs (MMP-15, 16, 17 and 24) were downregulated. The two remaining MT-MMPs (MMP-14 and 25) were upregulated in whole tissue. 相似文献39.
Many biochemical, physiological, and behavioral processes display daily rhythms generated by an internal timekeeping mechanism referred to as the circadian clock. The core oscillator driving this clock is located in the ventral part of the hypothalamus, the so called suprachiasmatic nuclei (SCN). At the molecular level, this oscillator is thought to be composed of interlocking autoregulatory feedback loops involving a set of clock genes. Among the components driving the mammalian circadian clock are the Period 1 and 2 (mPer1 and mPer2) and Cryptochrome 1 and 2 (mCry1 and mCry2) genes. A mutation in the mPer2 gene leads to a gradual loss of circadian rhythmicity in mice kept in constant darkness (DD). Here we show that inactivation of the mCry2 gene in mPer2 mutant mice restores circadian rhythmicity and normal clock gene expression patterns. Thus, mCry2 can act as a nonallelic suppressor of mPer2, which points to direct or indirect interactions of PER2 and CRY2 proteins. In marked contrast, inactivation of mCry1 in mPer2 mutant mice does not restore circadian rhythmicity but instead results in complete behavioral arrhythmicity in DD, indicating different effects of mCry1 and mCry2 in the clock mechanism 相似文献
40.