全文获取类型
收费全文 | 22299篇 |
免费 | 1598篇 |
国内免费 | 507篇 |
专业分类
耳鼻咽喉 | 270篇 |
儿科学 | 694篇 |
妇产科学 | 460篇 |
基础医学 | 2733篇 |
口腔科学 | 250篇 |
临床医学 | 1891篇 |
内科学 | 3827篇 |
皮肤病学 | 368篇 |
神经病学 | 1420篇 |
特种医学 | 828篇 |
外国民族医学 | 1篇 |
外科学 | 2706篇 |
综合类 | 1561篇 |
现状与发展 | 1篇 |
一般理论 | 23篇 |
预防医学 | 3322篇 |
眼科学 | 532篇 |
药学 | 1524篇 |
11篇 | |
中国医学 | 634篇 |
肿瘤学 | 1348篇 |
出版年
2024年 | 48篇 |
2023年 | 238篇 |
2022年 | 494篇 |
2021年 | 769篇 |
2020年 | 427篇 |
2019年 | 597篇 |
2018年 | 702篇 |
2017年 | 546篇 |
2016年 | 554篇 |
2015年 | 689篇 |
2014年 | 895篇 |
2013年 | 1259篇 |
2012年 | 1822篇 |
2011年 | 1886篇 |
2010年 | 1238篇 |
2009年 | 1003篇 |
2008年 | 1390篇 |
2007年 | 1443篇 |
2006年 | 1340篇 |
2005年 | 1103篇 |
2004年 | 1017篇 |
2003年 | 918篇 |
2002年 | 816篇 |
2001年 | 429篇 |
2000年 | 359篇 |
1999年 | 265篇 |
1998年 | 105篇 |
1997年 | 103篇 |
1996年 | 75篇 |
1995年 | 71篇 |
1994年 | 70篇 |
1993年 | 46篇 |
1992年 | 151篇 |
1991年 | 139篇 |
1990年 | 158篇 |
1989年 | 173篇 |
1988年 | 141篇 |
1987年 | 140篇 |
1986年 | 113篇 |
1985年 | 103篇 |
1984年 | 73篇 |
1983年 | 57篇 |
1982年 | 23篇 |
1981年 | 30篇 |
1980年 | 24篇 |
1979年 | 45篇 |
1975年 | 29篇 |
1974年 | 21篇 |
1973年 | 23篇 |
1972年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Alessio HM Hagerman AE Nagy S Philip B Byrnes RN Woodward JL Callahan P Wiley RL 《Physiology & behavior》2005,84(1):65-72
Voluntary and forced exercise decrease morbidity and mortality in laboratory animals. Caloric restriction has similar effects on health and unique benefits on life span. Nonetheless, in most experiments, animals do not have access to physical activity and are fed ad libitum (AL). We hypothesized that with regular access to either unlimited running wheel exercise (EX) or limited physical activity (PA), key biomarkers of health would be enhanced enough to counter some consequences of a sedentary AL lifestyle. This 16-month study compared body weight, tumor number and size, tissue lesions, oxidative stress, and reactive stress in (1) sedentary animals with no access to physical activity (SED); (2) animals with access to hour-long, twice weekly activity in a large box (PA); and (3) animals with access every other day to a running wheel (EX). At the end of the study, EX body weight was 8-9% lower than PA and SED. In addition, EX had no kidney lesions versus 50% in PA and SED, and had smaller tumor size (10+/-2 vs. 14+/-4 and 30+/-4 mm). Exhaustive exercise lowered glutathione/oxidized glutathione ratio in EX and PA, but in SED, the ratio was depressed even in resting animals. In all treatments, prolactin (PRL) levels were lower in resting animals than in acutely exercised animals. In conclusion, EX had the most favorable health biomarkers while SED had the least. PA did not confer gross health benefits different than the SED group, but was biochemically more similar to EX animals. 相似文献
62.
Muthotho JN Waiyaki PG Mbalu M Wairugu A Mwanthi B Odongo B 《African journal of health sciences》1995,2(1):232-235
Results of four years' studies from a number of hospitals in Kenya have shown that nosocomial infections in burns units are due to Methicillin Resistant Staphylococcus aureus (MRSA). Through chromosomal DNA and plasmid DNA, the stain is highly resistant to sulphonamide ointment and other antibiotics. 90% of patients admitted in burns units get colonized or infected with MRSA. The strain prolongs the duration of patients in hospitals. The burns degenerate to second and third degree burns, thereby necessitating skin grafting. The environment has been found to be contaminated with this strain with some staff members having chronic throat infections. Minocycline was found to be effective in treating the infected staff members. Cleaning this environment with Sodium dichloroisocyanurate (precepts)/Sodium hypochlorite (JIK) reduced drastically the mechanical transmission of bacteria in the units. The duration of stay of the patient was reduced. This shows that MRSA which is spread in government and private hospitals can cheaply be controlled by the proper use of disinfectants, antiseptics, and use of effective antibiotics when necessary. 相似文献
63.
Linking DJ-1 to neurodegeneration offers novel insights for understanding the pathogenesis of Parkinson’s disease 总被引:12,自引:0,他引:12
Rare monogenic forms of Parkinson's disease (PD) are promoting our understanding of the molecular pathways involved in the common, non-Mendelian forms of the disease. Here, we focus on PARK7, an autosomal recessive form of early-onset parkinsonism caused by mutations in the DJ-1 gene. We first review the genetics of this form and the rapidly expanding knowledge about the structure and biochemical properties of the DJ-1 protein. We also discuss how DJ-1 dysfunction might lead to neurodegeneration, and the implications of this novel piece of information for the pathogenesis of the common PD forms. Although much work remains to be done to clarify the biology of DJ-1, its proposed activity as a molecular chaperone and/or as oxidative sensor appear intriguing in the light of the current theories on the pathogenesis of PD. 相似文献
64.
65.
Ben Jemaa Z Mahjoubi F Ben Haj H'mida Y Hammami N Ben Ayed M Hammami A 《Pathologie-biologie》2004,52(2):82-88
Antimicrobial susceptibility and frequency of occurrence of clinical blood isolates in Sfax-Tunisia (1993-1998). The choice of antimicrobial therapy for the treatment of bacteremia is often empirical and based on the knowledge of susceptibility profiles of the most common bacteria causing such infections. This study determines the bacterial etiology of bacteremic episodes and antimicrobial susceptibility patterns recorded at a teaching hospital, from January 1993 to December 1998. We collected 2979 strains responsible for bacteremia. Gram negative bacteria were predominant (60%). The organisms recovered most frequently were Staphylococcus aureus (18.9%), Escherichia coli (14.7%), Klebsiella pneumoniae (14%) and Pseudomonas aeruginosa (7.6%). The incidence of resistance to methicillin were 17.4% for Staphylococcus aureus and 26.8% for coagulase negative Staphylococcus. No resistance to glycopeptides was observed among the enterococci and staphylococci studied. 27.7% of enterobacteriaceae were resistant to third generation cephalosporins. Imipenem was the most active agent against gram negative bacteria. To carry out a surveillance of bacteremic episodes occurring at every hospital, it is necessary to provide valuable information which should be the basis for effective empiric therapy. 相似文献
66.
Farhi J; Homburg R; Ferber A; Orvieto R; Ben Rafael Z 《Human reproduction (Oxford, England)》1997,12(2):241-243
The most important aspect of diminished ovarian reserve is the associated
decline in reproductive potential. Assessment of ovarian reserve is mainly
based on measurement of early follicular phase follicle stimulating hormone
(FSH) concentration. The objective of this study was to report the
identification of a group of 12 infertile women initially diagnosed as
having unexplained or anovulatory infertility, who had a normal baseline
hormonal profile and did not respond to repeated ovarian stimulation with
gonadotrophins. All developed ovarian failure within a relatively short
time span. Non-response to ovarian stimulation was defined by failure to
achieve development of follicles >12 mm and failure to raise oestradiol
concentration >350 pmol/l in two successive cycles of human menopausal
gonadotrophin (HMG) doses of up to five ampoules per day for 5-8 days.
Within a mean of 9 months following the failed attempts of ovarian
stimulation the mean day 3 FSH concentrations rose from 5.4 +/- 2.7 IU/l to
53.5 +/- 19.7 IU/l. In these patients, day 3 FSH concentration failed to
indicate the low ovarian reserve manifested only by lack of clinical
response to treatment with gonadotrophins which was the first sign of
impending ovarian failure. We conclude that women with normal early
follicular phase serum FSH concentrations who do not respond to ovarian
stimulation by HMG are at risk of developing ovarian failure within several
months.
相似文献
67.
The dose-response characteristics of dieldrin-mediated enhancementof liver tumour formation in CF-1 mice were analysed, usingexisting tumour data from chronic feeding studies at six levelsof continuous exposure, involving a total of > 1500 animals.The dose-response relationship can be expressed as: Dx x Tx= D0 x T0 = constant, where T0 = the median liver tumour inductionperiod in control CF-1 mice, Tx = the median liver tumour inductionperiod in dieldrin-treated mice at a dose level Dx, D0 = thebackground dose equivalent for the induction of spontaneousliver tumours, Dx = the sum of background dose (D0) and actualdieldrin dose (x). The relationship, which is a Druckrey equation(D x Tn = constant) where n = 1, indicates that: (i) the velocityof liver tumour development is proportional to the daily doselevel (Dx), (ii) the total tumourigenic dose is constant acrossall doses, (iii) the effects of dieldrin on the neo-plasticprocess in mouse liver are essentially irreversible and cumulative,and (iv) there is no evidence for a threshold level. However,when x «D0, the actual contribution of dieldrin to tumourformation is expected to be negligible. 相似文献
68.
Die Unfallchirurgie - 相似文献
69.
Wang Ben Deng Yu-xuan Yan Sha Xie Hong-fu Li Ji Jian Dan 《Lasers in medical science》2021,36(3):649-655
Lasers in Medical Science - Acne scarring is one of the most common facial skin disorders. The appropriate treatments for acne scars in patients with rosacea have not been studied. This study was... 相似文献
70.