全文获取类型
收费全文 | 2045篇 |
免费 | 212篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 72篇 |
妇产科学 | 31篇 |
基础医学 | 344篇 |
口腔科学 | 47篇 |
临床医学 | 266篇 |
内科学 | 437篇 |
皮肤病学 | 41篇 |
神经病学 | 234篇 |
特种医学 | 270篇 |
外科学 | 131篇 |
综合类 | 41篇 |
一般理论 | 1篇 |
预防医学 | 209篇 |
眼科学 | 26篇 |
药学 | 110篇 |
中国医学 | 1篇 |
肿瘤学 | 54篇 |
出版年
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 14篇 |
2018年 | 17篇 |
2017年 | 18篇 |
2016年 | 21篇 |
2015年 | 30篇 |
2014年 | 29篇 |
2013年 | 63篇 |
2012年 | 55篇 |
2011年 | 63篇 |
2010年 | 53篇 |
2009年 | 63篇 |
2008年 | 74篇 |
2007年 | 101篇 |
2006年 | 70篇 |
2005年 | 75篇 |
2004年 | 60篇 |
2003年 | 65篇 |
2002年 | 54篇 |
2001年 | 46篇 |
2000年 | 49篇 |
1999年 | 49篇 |
1998年 | 79篇 |
1997年 | 84篇 |
1996年 | 94篇 |
1995年 | 77篇 |
1994年 | 58篇 |
1993年 | 62篇 |
1992年 | 32篇 |
1991年 | 42篇 |
1990年 | 43篇 |
1989年 | 73篇 |
1988年 | 43篇 |
1987年 | 52篇 |
1986年 | 41篇 |
1985年 | 59篇 |
1984年 | 38篇 |
1983年 | 47篇 |
1982年 | 46篇 |
1981年 | 36篇 |
1980年 | 35篇 |
1979年 | 26篇 |
1978年 | 29篇 |
1977年 | 26篇 |
1976年 | 11篇 |
1975年 | 12篇 |
1971年 | 10篇 |
1970年 | 13篇 |
1969年 | 15篇 |
排序方式: 共有2322条查询结果,搜索用时 15 毫秒
141.
A single normal ultrasonographic scan at age 65 years rules out significant aneurysm disease for life in men. 总被引:4,自引:0,他引:4
P Crow E Shaw J J Earnshaw K R Poskitt M R Whyman B P Heather 《The British journal of surgery》2001,88(7):941-944
BACKGROUND: Screening for abdominal aortic aneurysm (AAA) has been carried out in Gloucestershire since 1990. All men in the county are offered aortic ultrasonography in their 65th year. Men with an aortic diameter of less than 26 mm are considered 'normal' and no follow-up is arranged. The aim of this study was to ascertain if men with 'normal' aortic diameters at age 65 years ever develop a clinically significant aneurysm. METHODS: A cohort study was performed on 223 65-year-old men who had an aorta of less than 26 mm in diameter in 1988. These men had repeat ultrasonography in 1993 and 2000. The causes of death in men who died during this interval were investigated. RESULTS: Eight men were lost to follow-up. As far as it was possible to ascertain, none of the 86 men who died over the 12-year interval did so from ruptured AAA. There was no clinically significant increase in mean aortic diameter in the remaining 129 men who had three serial ultrasonographic scans over the 12-year interval. CONCLUSION: A single, 'normal' ultrasound scan at age 65 years effectively rules out the risk of clinically significant aneurysm disease for life in men. 相似文献
142.
Su BW Protopsaltis TS Koff MF Chang KP Strauch RJ Crow SA Rosenwasser MP 《The Journal of hand surgery》2005,30(2):237-245
PURPOSE: Stainless steel suture is high in tensile strength but is not widely used in flexor tendon repair because of difficulty with handling and knot tying. The purpose of this study was to examine the biomechanical characteristics of the single-strand multifilament stainless steel Teno Fix device (Ortheon Medical, Winter Park, FL) designed for zone II flexor digitorum profundus (FDP) tendon repair. METHODS: Sixty cadaveric flexor tendons were transected and randomized to receive a Teno Fix or 4-stranded (3-0 or 4-0 braided polyester) suture repair; all repairs were tested with and without a 5-0 monofilament polypropylene circumferential epitendinous suture. By using a material testing system all tendons were tested to failure in tension using a linear model with a loading rate of 1 mm/s. Stiffness, force, and energy at both 2-mm gap and peak force were calculated from the resulting force-displacement curves. RESULTS: The 2-mm gapping force was significantly greater for the Teno Fix and the 3-0 repairs than for the 4-0 repairs. The energy absorbed up to 2-mm gap was significantly greater for the Teno Fix, however, than for all suture repairs both with and without a circumferential suture. There was no statistically significant difference in peak force or energy absorbed at peak force between the Teno Fix and suture repairs; the average gap at peak force for all repairs was 5.2 mm. The addition of a circumferential suture increased the 2-mm gapping and peak forces of the Teno Fix repair to 54.5 N and 66.7 N, respectively. CONCLUSIONS: Increased strength and energy absorbed at 2-mm gap and ease of installation makes the Teno Fix a promising repair method. 相似文献
143.
144.
Soubhagya R. Nayak Ashwin Krishnamurthy SJ Madhan Kumar Latha V. Prabhu Bhagath Kumar Potu Sujatha D’Costa Anu Vinod Ranade 《Hand (New York, N.Y.)》2010,5(1):31-36
The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7 mm. The present study concludes that the median–ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial–median–ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand. 相似文献
145.
0 引言 腹泻乃小儿最常见病 ,尤以 2岁以下婴幼儿最为常见 .年龄越小 ,发病率越高 ,且多在夏、秋季发病 .小儿患病后惧怕打针 ,服药以及输液 ,给治疗带来一些困难 . 12 a来 ,我们用自拟的止泻散敷脐治疗婴幼儿泄泻 ,效果良好 .1 对象和方法1.1 对象 1998- 0 6 / 1999- 10婴幼儿腹泻发病高峰期门诊病例 10 0 (男 6 6 ,女 34 )例 ,年龄 2月龄~ 5岁 .肠炎 5 8例 ,单纯消化不良 42例 . 6 7例曾多次治疗 ,33例初诊 .凡接受治疗之患儿 ,一律停止用其他药物 .1.2 方法 药物组成 :川椒 12 g,干姜 12 g,小茴香 12 g,白芷 2 0 g,吴茱萸 5 g,… 相似文献
146.
Blake SM Caspersen CJ Finnegan J Crow RA Mittlemark MB Ringhofer KR 《American journal of health promotion : AJHP》1996,11(1):23-34
PURPOSE: To assess organizational and employee participation during three community-wide worksite exercise competitions in two communities. DESIGN: A one-group, posttest-only design was used. Lack of controls, exercise baseline, and the short-term nature of the interventions were limitations. SETTING: The Minnesota Heart Health Program conducted annual exercise campaigns between 1982 and 1989 within three intervention communities to reduce behavioral risk for cardiovascular disease. The Shape Up Challenge was a worksite exercise competition designed, in conjunction with other campaign activities, to increase levels of physical activity. SUBJECTS: A total of 119 participating companies in two Minnesota communities, and 17,626 employees within these worksites, composed the subjects in this study. INTERVENTION: Eligible worksites were invited to participate in a month-long competition during which employees recorded minutes spent daily in aerobic activities. Incentives were established to promote intragroup cooperation and intergroup competition. Companies competed for awards that were based on average minutes of exercise per employee versus per participant. MEASURES: Numbers of companies recruited and participating, campaign activities, minutes of exercise, and costs were recorded on implementation logs. Companies completed surveys describing business type, number and sex of employees, existing health promotion programs, and perceived benefits of participation. RESULTS: Of the 365 companies invited to participate, 33% participated (range 15% to 50%). Participating companies were more likely than nonparticipating companies to offer other health promotion programs and perceived greater benefits from participation. Women and smaller companies had significantly greater participation rates than men and larger companies. Average employee participation rates ranged from as high as 84% in smaller organizations to as low as 16% as organization size increased. CONCLUSIONS: Community-based worksite exercise competitions appear to be a viable strategy for promoting employee exercise, particularly in smaller companies. Group-based contingencies applied in natural work units may facilitate employee participation. Further research is needed to assess the relative efficacy of this approach, compare alternative incentives, and identify strategies to enhance exercise maintenance after the intervention has ceased. 相似文献
147.
148.
149.