全文获取类型
收费全文 | 2740篇 |
免费 | 280篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 130篇 |
妇产科学 | 63篇 |
基础医学 | 357篇 |
口腔科学 | 54篇 |
临床医学 | 363篇 |
内科学 | 479篇 |
皮肤病学 | 48篇 |
神经病学 | 251篇 |
特种医学 | 277篇 |
外科学 | 442篇 |
综合类 | 74篇 |
一般理论 | 1篇 |
预防医学 | 204篇 |
眼科学 | 20篇 |
药学 | 205篇 |
中国医学 | 5篇 |
肿瘤学 | 109篇 |
出版年
2021年 | 36篇 |
2020年 | 23篇 |
2019年 | 37篇 |
2018年 | 41篇 |
2017年 | 33篇 |
2016年 | 30篇 |
2015年 | 50篇 |
2014年 | 57篇 |
2013年 | 73篇 |
2012年 | 83篇 |
2011年 | 65篇 |
2010年 | 66篇 |
2009年 | 84篇 |
2008年 | 82篇 |
2007年 | 130篇 |
2006年 | 98篇 |
2005年 | 91篇 |
2004年 | 92篇 |
2003年 | 67篇 |
2002年 | 76篇 |
2001年 | 92篇 |
2000年 | 78篇 |
1999年 | 65篇 |
1998年 | 81篇 |
1997年 | 93篇 |
1996年 | 94篇 |
1995年 | 84篇 |
1994年 | 62篇 |
1993年 | 80篇 |
1992年 | 66篇 |
1991年 | 60篇 |
1990年 | 52篇 |
1989年 | 79篇 |
1988年 | 72篇 |
1987年 | 70篇 |
1986年 | 52篇 |
1985年 | 58篇 |
1984年 | 44篇 |
1983年 | 54篇 |
1982年 | 46篇 |
1981年 | 36篇 |
1980年 | 42篇 |
1979年 | 30篇 |
1978年 | 37篇 |
1977年 | 26篇 |
1976年 | 25篇 |
1975年 | 21篇 |
1974年 | 21篇 |
1973年 | 18篇 |
1972年 | 16篇 |
排序方式: 共有3089条查询结果,搜索用时 484 毫秒
21.
J. Bolton R. Abbott M. Kiely M. Alleyne S. Bell L. Stubbs M. Slevin 《Journal of human nutrition and dietetics》1992,5(2):79-84
This study set out to compare the long-term palatability of three oral sip-feed supplements. Sixty patients with various malignancies were randomized to receive one of three products—Build-Up, Fortimel and Fortisip. Participants were encouraged to take as much of the supplements each day for as long as they could manage. At the initial tasting, palatability and acceptability of the products was recorded and this was repeated throughout the trial period. Patients' reasons for discontinuing the trial were noted.
Build-Up was found to be the best-tolerated product of the three. It was taken for a significantly longer time than either Fortimel or Fortisip. There was an indication that Build-Up was more acceptable at the initial tasting than Fortisip but not Fortimel. A smaller proportion of patients stopped taking Build-Up due to flavour-related reasons compared to Fortisip but there was no significant difference between Build-Up and Fortimel. In all, 54% of the patients discontinued the trial for flavour-related reasons. Thirty-five per cent found that the sip-feeds they had been allotted unpalatable at the initial tasting, while 19% stopped the trial due to 'flavour fatigue'. Only 10% of the sample continued taking their allotted product for 90 days or more. 相似文献
Build-Up was found to be the best-tolerated product of the three. It was taken for a significantly longer time than either Fortimel or Fortisip. There was an indication that Build-Up was more acceptable at the initial tasting than Fortisip but not Fortimel. A smaller proportion of patients stopped taking Build-Up due to flavour-related reasons compared to Fortisip but there was no significant difference between Build-Up and Fortimel. In all, 54% of the patients discontinued the trial for flavour-related reasons. Thirty-five per cent found that the sip-feeds they had been allotted unpalatable at the initial tasting, while 19% stopped the trial due to 'flavour fatigue'. Only 10% of the sample continued taking their allotted product for 90 days or more. 相似文献
22.
N E Miller C H Bolton T M Hayes D Bainton J W Yarnell I A Baker P M Sweetnam 《Journal of epidemiology and community health》1988,42(3):220-225
In surveys of 4860 middle-aged men in Caerphilly (South Wales) and Speedwell (Bristol) alcohol consumption has been related to high density lipoprotein (HDL) cholesterol and its major subfractions, HDL2 and HDL3, measured in a single fasting blood sample. The results confirm that high density lipoprotein cholesterol concentration increases as the amount of alcohol regularly consumed increases. The relationship appears to be linear and is independent of age, smoking habit, body mass index, low density lipoprotein cholesterol and plasma total triglyceride. This rise in HDL cholesterol is not mediated through either HDL2 cholesterol or HDL3 cholesterol alone. Both subclasses increase significantly and by similar amounts with increasing alcohol intake. 相似文献
23.
24.
25.
26.
D A Ogden A A McKechnie D A Bolton R B Rankin S E Dobbins J A Clements 《Journal of pharmaceutical and biomedical analysis》1989,7(11):1273-1280
A method is described for the determination of pipothiazine in human plasma, based on reversed-phase HPLC. The method has been applied in a pharmacokinetic study of pipothiazine in six psychiatric patients receiving repeated depot intramuscular injections for six months. A number of compounds likely to be taken concurrently by patients were tested for potential to interfere with the assay. There was no evidence of "dose-dumping" in the period following injection. Comparison of the pharmacokinetic profiles after the first and sixth injections showed no evidence of drug accumulation. 相似文献
27.
Calcium events in smooth muscles and their interstitial cells; physiological roles of sparks 总被引:2,自引:1,他引:2
Tom B. Bolton 《The Journal of physiology》2006,570(1):5-11
The observation of spontaneous sporadic releases of packets of stored calcium made 20 years ago has opened up a number of new concepts in smooth muscle physiology: (1) the calcium release sites are ryanodine and inositol 1,4,5-trisphosphate (IP3 ) receptor channels which contribute to cell-wide increases in [Ca2 + ]i in response to cell depolarization, activation of IP3 -generating receptors, or other stimuli; (2) changes in [Ca2 + ]i act back on the cell membrane to activate or modulate K+ , Cl− and cation channel activity so affecting contraction, in arterial smooth muscle for example affecting blood pressure; (3) IP3 production is voltage dependent and is believed to contribute to pacemaker potentials and to refractory periods which control the rhythmical motility of many hollow organs. Most smooth muscle tissues contain interstitial cells (ICs) in addition to contractile smooth muscle cells (SMCs). The interactions of these internal mechanisms, and in turn the interactions of SMCs and ICs in various smooth muscle tissues, are major factors in determining the unique physiological profiles of individual smooth muscles. 相似文献
28.
A comparison of Skirrow's, Butzler's, Blaser's, Campy-BAP and Preston media for Campylobacter spp was made using human, animal and environmental specimens. Butzler's medium gave the lowest isolation rate and Preston medium, which was the most selective, the highest isolation rate. Enrichment culture using Preston enrichment broth gave a higher isolation rate than direct plating onto Preston medium. 相似文献
29.
O'Brien SG Guilhot F Larson RA Gathmann I Baccarani M Cervantes F Cornelissen JJ Fischer T Hochhaus A Hughes T Lechner K Nielsen JL Rousselot P Reiffers J Saglio G Shepherd J Simonsson B Gratwohl A Goldman JM Kantarjian H Taylor K Verhoef G Bolton AE Capdeville R Druker BJ;IRIS Investigators 《The New England journal of medicine》2003,348(11):994-1004
30.
CTLA-4 is required for the induction of high dose oral tolerance 总被引:5,自引:3,他引:5
Samoilova EB; Horton JL; Zhang H; Khoury SJ; Weiner HL; Chen Y 《International immunology》1998,10(4):491-498
Mucosal and systemic administrations of high dose antigens induce long-
lasting peripheral T cell tolerance. We and others have shown that high
dose peripheral T cell tolerance is mediated by anergy or deletion and is
preceded by T cell activation. Co-stimulatory molecules B7-1 (CD80)/B7-2
(CD86) and their counter-receptors CD28/CTLA-4 play pivotal roles in T cell
activation and immune regulation. In the present study, we examined the
roles of the B7 co-stimulation pathway in the generation of high dose
peripheral T cell tolerance. We found that blocking B7:CD28/CTLA-4
interaction at the time of tolerance induction partially prevented T cell
tolerance, whereas selective blockade of B7:CTLA-4 interaction completely
abrogated peripheral T cell tolerance induced by either oral or i.p.
antigens. These results suggest that CTLA-4-mediated feedback regulation
plays a crucial role in the induction of high dose peripheral T cell
tolerance.
相似文献