全文获取类型
收费全文 | 2018篇 |
免费 | 162篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 59篇 |
妇产科学 | 39篇 |
基础医学 | 208篇 |
口腔科学 | 46篇 |
临床医学 | 641篇 |
内科学 | 324篇 |
皮肤病学 | 10篇 |
神经病学 | 112篇 |
特种医学 | 141篇 |
外科学 | 149篇 |
综合类 | 68篇 |
一般理论 | 1篇 |
预防医学 | 171篇 |
眼科学 | 8篇 |
药学 | 135篇 |
肿瘤学 | 103篇 |
出版年
2021年 | 19篇 |
2020年 | 12篇 |
2019年 | 18篇 |
2018年 | 39篇 |
2017年 | 22篇 |
2016年 | 21篇 |
2015年 | 24篇 |
2014年 | 38篇 |
2013年 | 76篇 |
2012年 | 64篇 |
2011年 | 49篇 |
2010年 | 55篇 |
2009年 | 58篇 |
2008年 | 61篇 |
2007年 | 68篇 |
2006年 | 62篇 |
2005年 | 56篇 |
2004年 | 69篇 |
2003年 | 44篇 |
2002年 | 67篇 |
2001年 | 64篇 |
2000年 | 62篇 |
1999年 | 64篇 |
1998年 | 111篇 |
1997年 | 105篇 |
1996年 | 86篇 |
1995年 | 72篇 |
1994年 | 62篇 |
1993年 | 62篇 |
1992年 | 43篇 |
1991年 | 43篇 |
1990年 | 45篇 |
1989年 | 43篇 |
1988年 | 46篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 38篇 |
1984年 | 22篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 13篇 |
1979年 | 26篇 |
1978年 | 15篇 |
1977年 | 14篇 |
1974年 | 10篇 |
1972年 | 19篇 |
1971年 | 14篇 |
1970年 | 9篇 |
1968年 | 12篇 |
排序方式: 共有2217条查询结果,搜索用时 0 毫秒
71.
De Marco M Weiner B Meade SA Hadley M Boyd C Goldmon M Green M Manning M Howard DL Godley P Corbie-Smith G 《Journal of the National Medical Association》2011,103(9-10):960-967
We assessed church readiness to engage in health disparities research using a newly developed instrument, examined the correlates of readiness, and described strategies that churches used to promote health. We pilot tested the instrument with churches in a church-academic partnership (n = 12). We determined level of readiness to engage in research and assessed correlates of readiness. We also conducted interviews with participating pastors to explore strategies they had in place to support research engagement. Churches scored fairly high in readiness (average of 4.04 out of 5). Churches with a pastor who promoted the importance of good nutrition in a sermon or had a budget for health-related activities had significantly higher readiness scores than churches without such practices. Having a tool to evaluate church readiness to engage in research will inform targeted technical assistance and research projects that will strengthen church-academic partnerships and improve capacity to address health disparities. 相似文献
72.
Leptin-induced decrease in food intake in chickens 总被引:6,自引:0,他引:6
Denbow DM Meade S Robertson A McMurtry JP Richards M Ashwell C 《Physiology & behavior》2000,69(3):359-362
The effect of intracerebroventricular (i.c.v.) injection of leptin was investigated using broiler and Single Comb White Leghorn (SCWL)-type chickens. These represent relatively fast- and slow-growing birds, respectively. The i.c.v. injection of leptin decreased food intake in both broilers and Leghorns in a dose-dependent manner. The most efficacious dose appeared to be 10 microg in both types of chickens. Water intake was generally not affected by leptin, indicating that this effect was not due to general malaise. It appears that leptin can act within the central nervous sytstem of birds to decrease food intake. 相似文献
73.
Background
Chronic obstructive pulmonary disease (COPD) is a major but neglected public health problem. Currently 1.4% of the England population has a clinical diagnosis of COPD, but the true burden of the disease has not been known with certainty, as many cases remain undiagnosed. 相似文献74.
75.
S G Shaffer H W Kilbride L K Hayen V M Meade B A Warady 《The Journal of pediatrics》1992,121(2):275-279
PURPOSE: To assess the frequency and pathogenesis of hyperkalemia in the very low birth weight infant. METHODS: Infants who weighed less than 1000 gm at birth were prospectively entered into the study within 12 hours of birth. Potential risk factors for hyperkalemia were assessed. Body weight, fluid and electrolyte balance, serum levels of sodium and potassium, creatinine clearance, fractional sodium excretion, and urine sodium/potassium ratio were measured every 8 hours for 72 hours. Measurements of plasma renin, serum aldosterone, and plasma atrial natriuretic factor were made at study entry and repeated when hyperkalemia (serum potassium greater than 6.5 mmol/L) occurred or at 72 hours. Infants in whom hyperkalemia developed were compared with those in whom it did not. RESULTS: Thirty-one infants completed the study; hyperkalemia developed in 16 (51.6%). The only difference in the occurrence of perinatal complications was the more frequent occurrence of pH less than 7.20 in infants with subsequent development of hyperkalemia. Creatinine clearance, urine output, and potassium excretion were significantly lower in the hyperkalemia group during the first 24 hours. Serum potassium concentration at 24 hours was inversely related to urine output in the prior 24 hours. Fractional sodium excretion, urine sodium/potassium ratio, and levels of renin, aldosterone, and atrial natriuretic factor did not differ between groups. CONCLUSIONS: Hyperkalemia is a frequent complication in very low birth weight infants. Infants with low urinary flow rates during the first few hours after birth are at greatest risk for the development of hyperkalemia. 相似文献
76.
Richard Reid MD Katherine H. Omoto MS Sheryl L. Precop RN NP Nancy R. Berman RN CS MSN Lisa H. Rutledge BA Steven M. Dean MD Mark Pleatment MD 《American journal of obstetrics and gynecology》1995,172(6):1684-1701
Objective: The management of chronic vulvovaginal pain, not explicable on specific histologic grounds, presents a major problem in referral centers for lower genital tract diseases.Study design: This article reports on a two-step protocol in a sample of 175 medical nonresponders, drawn from a 2-year cohort of 725 women with vulvovaginal pain. The first maneuver was the use of a flashlamp-excited dye laser to selectively photocoagulate symptomatic subepithelial blood vessels in 168 women; the second was the microsurgical removal of chronically painful Bartholin's glands in 52 women not responsive or not suited to flashlamp-excited dye laser photothermolysis.Results: Dye laser response rates werer independent of whether patients manifested macroscopic focl of painful erythema (“vestibular adenitis”) or just colposcopically apparent hyperemia-ectasia of the individual blood vessels (“pruritic papillomatosis”) (55% vs 45% after a single surgical procedure; 76% vs 65% after serial retreatment; p not significant). Conversely, response rates were much lower among women in whom pressure on the Bartholin's glands produced sharp, lancinating pain (15% vs 66% after a single surgical procedure; 22% vs 93% after serial retreatment; p < 0.001). Forty-two (85%) of 50 patients with flashlamp-excited dye laser failure had deep pain; however, the impasse to progress was broken by gland removal. Final response rates were 92.5% (complete response 62%; partial response 30%) in the “surface-only” group and 80.3% in the “surface-plus-deep” group (χ2 = 14.9; p < 0.001). The major complication was acute bacterial cellulitis, occurring in the first postoperative week. Modification of the treatment protocol to include topical antibiotics with an occlusive dressing reduced the cellulitis rate from 17.2% to 2.5%. In four women (1.8%) Koebner-like exophytic condylomas also developed within 1 month of flashlamp-excited dye laser surgery.Conclusion: The availability of a safe, efficacious, and relatively noninvasive treatment should reduce the need for resective surgery in most patients with idiopathic vulvodynia. 1995; 172; 1684–1701.) 相似文献
77.
Because bacterial colonization of medical devices may result in clinical infection, it is conceivable that antimicrobial impregnation of tissue expanders may reduce the rate of infection. The objective of this in vitro study was to examine the spectrum, durability, and shelf-life antimicrobial activity of minocycline/rifampin-impregnated silicone tissue expander shells. The impregnated devices exhibited zones of inhibition at baseline against Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli. The impregnated devices exhibited strong residual activity against S. epidermidis and S. aureus after suspension in serum at 37 degrees C for 4 weeks. There was no significant decrease in the size of zones of inhibition after storing the impregnated devices at room temperature for 1 year. These results indicate that minocycline/rifampin-impregnated tissue expander shells provide broad-spectrum and durable antimicrobial activity and that the shelf-life antimicrobial activity exceeds 1 year. These findings prompt future exploration of the anti-infective efficacy of these antimicrobial-impregnated devices. 相似文献
78.
79.
The HMC-1 mast cell line has both adenosine A(3) and A(2b) receptors on its surface, but only agonists of the A(2b) receptor are effective at releasing interleukin 8. Object of this study was to look for co-factors for adenosine A(2b) receptor activation. There was a powerful and statistically significant synergy for release of IL-8, both at the mRNA level (measured after 4 hr) and protein level (measured after 24 hr), between adenosine A(2b) receptor agonists and stem cell factor (SCF). Suitable concentrations for showing synergy were 100 ng/mL SCF and 3 microM 5'-N-ethylcarboxamidoadenosine (NECA). At these concentrations, the IL-8 released into the culture medium after SCF and NECA together was typically 3-5-fold greater in amount than the sum of the amounts of IL-8 released after exposure to the same concentrations of NECA and SCF separately. Since mast cells may be exposed to both adenosine and stem cell factor in the diseased lung, the synergy observed in this model system may have implications for asthma. 相似文献
80.