全文获取类型
收费全文 | 9195篇 |
免费 | 821篇 |
国内免费 | 106篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 117篇 |
妇产科学 | 130篇 |
基础医学 | 662篇 |
口腔科学 | 251篇 |
临床医学 | 2010篇 |
内科学 | 1173篇 |
皮肤病学 | 59篇 |
神经病学 | 657篇 |
特种医学 | 278篇 |
外科学 | 433篇 |
综合类 | 1223篇 |
一般理论 | 2篇 |
预防医学 | 1949篇 |
眼科学 | 115篇 |
药学 | 515篇 |
6篇 | |
中国医学 | 188篇 |
肿瘤学 | 260篇 |
出版年
2024年 | 37篇 |
2023年 | 200篇 |
2022年 | 241篇 |
2021年 | 338篇 |
2020年 | 343篇 |
2019年 | 385篇 |
2018年 | 376篇 |
2017年 | 388篇 |
2016年 | 349篇 |
2015年 | 316篇 |
2014年 | 582篇 |
2013年 | 745篇 |
2012年 | 534篇 |
2011年 | 562篇 |
2010年 | 466篇 |
2009年 | 485篇 |
2008年 | 527篇 |
2007年 | 481篇 |
2006年 | 426篇 |
2005年 | 362篇 |
2004年 | 273篇 |
2003年 | 225篇 |
2002年 | 200篇 |
2001年 | 163篇 |
2000年 | 136篇 |
1999年 | 134篇 |
1998年 | 83篇 |
1997年 | 102篇 |
1996年 | 68篇 |
1995年 | 63篇 |
1994年 | 54篇 |
1993年 | 53篇 |
1992年 | 42篇 |
1991年 | 43篇 |
1990年 | 34篇 |
1989年 | 26篇 |
1988年 | 22篇 |
1987年 | 26篇 |
1986年 | 25篇 |
1985年 | 27篇 |
1984年 | 34篇 |
1983年 | 14篇 |
1982年 | 37篇 |
1981年 | 16篇 |
1980年 | 20篇 |
1979年 | 15篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Histological appearances of the long saphenous vein 总被引:1,自引:0,他引:1
C M Milroy D J Scott J D Beard M Horrocks J W Bradfield 《The Journal of pathology》1989,159(4):311-316
The long saphenous vein is frequently used as a graft in both coronary artery and femoro-distal bypass surgery. The histological changes which are seen after implantation into the arterial system have been well documented in the past, but little attention has been focused on the histological appearances of the donor long saphenous vein prior to grafting. In this study, samples of the long saphenous vein in excess of that required for bypass have been examined. In none of the veins did the histological appearances conform to the described normal. All showed evidence of intimal fibrosis which contained elastic tissue and enmeshed smooth muscle cells. The longitudinal and circular muscle layers showed evidence of muscle cell hypertrophy with increase in intervening connective tissue. Elsewhere, similar histological changes have been attributed to 'arterialization'. This study shows that many of the changes are present prior to grafting and may be important in graft failure. 相似文献
72.
青岛市中青年领导干部心理健康状况的调查研究 总被引:7,自引:0,他引:7
本研究采用部卷方式,调查探讨了青岛市中青年领导干部的心理健康状况,结果表明,(1)青岛市中青年领导干部的心理健康状况远远好于普通人群。(2)青岛市中青年领导干部的“自我与经验的和谐水平”以及“自我的灵活性”极明显地高于大学生常模。(2)青岛市青年领导干部的“自我与经验的不和谐”水平与其心理健康程度密切相关;其“自我的灵活性”与心理健康的多个方面也有着密切的相关。 相似文献
73.
A. Meier U. Gübelin Prof. Dr. P. Weidmann M. Grimm G. Keusch Z. Glück I. Minder C. Beretta-Piccoli 《Journal of molecular medicine (Berlin, Germany)》1980,58(21):1183-1188
Summary The interrelationships among age, cardiovascular pressor reactivity to intravenously infused norepinephrine (NE) or angiotensin II, and endogenous plasma NE or renin (PRA) levels were evaluated in 31 normal subjects and 37 patients with essential hypertension. In normal subjects both angiotensin II pressor dose and PRA decreased progressively with aging. Angiotensin pressor dose correlated positively with PRA (r=0.41,P<0.025) and inversely with age (r=–0.46,P<0.02). NE pressor dose and basal plasma NE were also positively correlated (r=0.53,P<0.005), but the two factors remained largely unchanged with aging. Findings in essential hypertension differed in certain aspects. Angiotensin II pressor dose did not correlate with either basal PRA or age; and pressor doses of NE and angiotensin II tended to be lower in some patients than in normal subjects. These findings indicate that aging is accompanied by a physiologic increase in cardiovascular reactivity to angiotensin II, probably due to a concomitant decrease in circulating renin. The dissociation between angiotensin pressor dose and PRA in essential hypertension suggests an interference from an other factor.This work was supported by the Swiss National Science Foundation 相似文献
74.
T. Y. Wu X. Q. Wang C. Y. Wei H. W. Cheng X. Z. Wang Y. Li Ge-Dong H. N. Zhao P. Young G. L. Li Z. G. Wang 《Comparative clinical pathology》2005,14(1):25-35
Tibetans form a population which has resided on the Qinghai–Tibetan plateau for thousands of years, and are reported to have less hemoglobin than Han Chinese lowlanders who have migrated to the plateau. However, for various altitudes, detailed comparisons of hemoglobin in the two ethnic groups has not been reported. We investigated the hypothesis that the effects of altitude, age, and gender on hemoglobin concentration would differ between Han and Tibetan residents of the plateau. Hematological parameters for both genders were determined in healthy Tibetan adults (n=3,000) and children (n=332), and healthy Han Chinese adults (n=2,612) and children (n=275), aged 5–60 years living at four different altitudes (mean altitude of 2,664, 3,813, 4,525, and 5,200 m). Hemoglobin values increased with altitude for all ages in both ethnic groups and in both genders. The gain in hemoglobin with altitude had the rank order: Han males > Han females > Tibetan males and females. Even before puberty, Han children had more hemoglobin than Tibetan children. An effect of age on hemoglobin was seen at the time of puberty in men, but not in women. A positive correlation was found between hemoglobin concentration and age in adult Han males and females, but not in Tibetan males, and only at the higher altitudes, in Tibetan females. In both Tibetans and Hans, males had higher hemoglobin values than females at each altitude, but the gender differences increased with altitude in Han, whereas it either decreased or did not change in Tibetans. Examination of hemoglobin levels by histogram showed non-Gaussian distributions: Tibetan men and women had skewing to higher values, whereas Han men and women had skewing in the opposite direction. We conclude that increasing age and the effect of gender in Tibetans are associated with different hemoglobin responses to altitude than in Han, and we speculate that genetic influences may be involved. 相似文献
75.
农村老年人心理健康状况的调查分析 总被引:10,自引:2,他引:10
随着经济的发展和社会的进步 ,人口老龄化已经成为当今世界人口发展的一种必然趋势。因此 ,老龄问题日益受到关注。研究老年人的心理健康状况及其影响因素对如何提高老年人的生活质量具有重要的指导意义。国内已有一些学者对老年人的心理健康状况进行了研究[1- 7] ,但研究的对象主要是城市老年人 ,关于农村老年人的心理健康状况的研究极少。因此 ,本文想就这一问题作些探讨。1 对象与方法1.1 对象在湖州市所辖三县三区各抽取 9个行政村 ,每个行政村随机抽取 13~ 14个年龄在 6 0岁以上 (包括 6 0岁 )的老年农民进行调查 ,其中有 16人资料… 相似文献
76.
All citizens (N = 22066) aged 16 to 65 of a medium-sized Belgiantown were personally invited to CPR training sessions held intheir neighbourhood. 1152 responded by attending a trainingsession. Those who did not so respond were surveyed (randomsample N=600) for reasons of their not coming. The sample fittedwell with census data for gender, age and suburb location butnot for job, because retired persons and women at home wereover represented. 123 persons did not want to answer the questions. 116 personssaid they were already trained in CPR, 276 said they would accepton a future occasion and 82 said they would not. Three personsdid not answer this question. There was no discrimination for job, gender and suburb locationbetween those who did and did not accept a future training opportunity,nor was the existence of a heart patient among relatives. Theolder the person, the less inclined was that person to participatein CPR training (age effect x2 = 17.17, d.f. = 9, P<0.05).The 276 who accepted future training, chose their workplace(221) and/or their social meeting place (club etc.) as the placewhere this future training should be held. We suggest that CPR training is well accepted and that the trainingopportunities should be given at places of work and social gatherings. 相似文献
77.
我国正常生育力男子精浆的微量元素研究 总被引:12,自引:5,他引:7
本文报告测试了68例正常生育力成年男子精浆中的锌、铜,铁等微量元素和镁,测试结果如下:锌130±5.64μg/ml,铜1.84±0.158μg/ml,铁0.801±0.104μg/ml,镁103.86±10.01μg/ml。所测得的数值均在正常范围内。在正常范围内的精液,精浆中的锌、镁含量与精液质量(精子密度和活动力)之间无显著差异。但铜的含量与精子活动度关系密切,含量高则活动度差,反之则活动度好。铁的含量与精子密度关系也十分密切,含量高时精子密度也高。 相似文献
78.
摘 要: 目的:探究中老年人颈动脉斑块与血清25羟维生素D (25-OH-D) 的相关性。 方法:选取2019年1月—2020
年 12 月自愿参与该研究的上海市浦东新区北蔡社区常住居民 412 人为研究对象,测定及记录其一般临床资料及血清
25-OH-D 等实验室检测结果。依据血管 B 超结果将研究对象分为有斑块组 268 人和无斑块组 144 人,比较两组人群血清
25-OH-D水平差异,用Pearson相关性分析各变量的关系,采用logistic回归分析颈动脉斑块形成的危险因素。结果:有斑块
组血清 25-OH-D 为 (45.18±18.71) nmol/L,无斑块组为 (56.12±19.54) nmol/L,两组差异有统计学意义 (χ2=5.573,P<
0.05)。相关性分析显示颈动脉斑块与收缩压、HbA1c、年龄呈正相关 (r值分别为0.388、0.119和0.128,P值均<0.05);与
血清 25-OH-D 呈负相关 (r=-0.365,P<0.01)。血清 25-OH-D 是颈动脉斑块形成的独立相关因素 (OR=0.973,95%CI:
0.960,0.985,P<0.05)。结论:低水平血清25-OH-D是颈动脉斑块形成的独立危险因素。 相似文献
79.
《Health & place》2021
Within the United States South, the socio-religious norms that shape life for many residents may have public health implications. Drawing from 12 key informant interviews, this study explores the role of religious institutions in HIV care and prevention access among transgender people of color in Southern cities. Findings suggest that while religious anti-transgender stigma is pervasive, the regional importance of faith-based beliefs and institutions necessitates targeted faith-based initiatives for the population. Broadly, findings suggest regional environments may demand interventions that negotiate historically marginalizing relationships between at-risk groups and dominant cultural institutions. 相似文献
80.
Ushma D. Upadhyay Phoebe Y. Danza Torsten B. Neilands Jessica D. Gipson Claire D. Brindis Michelle J. Hindin Diana Greene Foster Shari L. Dworkin 《The Journal of adolescent health》2021,68(1):86-94
PurposeWe developed and validated a measure that assesses the latent construct of sexual and reproductive empowerment among adolescents and young adults. A specific measure for this group is critical because of their unique life stage and circumstances, which often includes frequent changes in sexual partners and involvement from parents in decision-making.MethodsAfter formative qualitative research, a review of the literature, and cognitive interviews, we developed 95 items representing nine dimensions of sexual and reproductive empowerment. Items were then fielded among a national sample of young people aged 15–24 years, and those who identified as sexually active completed a 3-month follow-up survey. We conducted psychometric analysis and scale validation.ResultsExploratory factor analysis on responses from 1,117 participants resulted in the Sexual and Reproductive Empowerment Scale for Adolescents and Young Adults, containing 23 items captured by seven subscales: comfort talking with partner; choice of partners, marriage, and children; parental support; sexual safety; self-love; sense of future; and sexual pleasure. Validation using logistic regression demonstrated that the subscales were consistently associated with sexual and reproductive health information and access to sexual and reproductive health services measured at baseline and moderately associated with the use of desired contraceptive methods at 3-month follow-up.ConclusionsThe Sexual and Reproductive Empowerment Scale for Adolescents and Young Adults is a new measure that assesses young people’s empowerment regarding sexual and reproductive health. It can be used by researchers, public health practitioners, and clinicians to measure sexual and reproductive empowerment among young people. 相似文献