全文获取类型
收费全文 | 379091篇 |
免费 | 25252篇 |
国内免费 | 8646篇 |
专业分类
耳鼻咽喉 | 4528篇 |
儿科学 | 9977篇 |
妇产科学 | 6676篇 |
基础医学 | 29402篇 |
口腔科学 | 8300篇 |
临床医学 | 44607篇 |
内科学 | 46132篇 |
皮肤病学 | 4655篇 |
神经病学 | 20711篇 |
特种医学 | 21900篇 |
外国民族医学 | 33篇 |
外科学 | 41222篇 |
综合类 | 55561篇 |
现状与发展 | 12篇 |
一般理论 | 29篇 |
预防医学 | 35871篇 |
眼科学 | 5758篇 |
药学 | 31516篇 |
403篇 | |
中国医学 | 30990篇 |
肿瘤学 | 14706篇 |
出版年
2023年 | 5905篇 |
2022年 | 10770篇 |
2021年 | 14550篇 |
2020年 | 13475篇 |
2019年 | 18837篇 |
2018年 | 16775篇 |
2017年 | 13814篇 |
2016年 | 11589篇 |
2015年 | 10895篇 |
2014年 | 22441篇 |
2013年 | 23551篇 |
2012年 | 20701篇 |
2011年 | 22382篇 |
2010年 | 18178篇 |
2009年 | 16946篇 |
2008年 | 16563篇 |
2007年 | 16832篇 |
2006年 | 14730篇 |
2005年 | 12834篇 |
2004年 | 10449篇 |
2003年 | 9140篇 |
2002年 | 7136篇 |
2001年 | 6503篇 |
2000年 | 5337篇 |
1999年 | 4564篇 |
1998年 | 3740篇 |
1997年 | 3535篇 |
1996年 | 2989篇 |
1995年 | 2908篇 |
1994年 | 2762篇 |
1993年 | 2203篇 |
1992年 | 2207篇 |
1991年 | 1889篇 |
1990年 | 1675篇 |
1989年 | 1508篇 |
1988年 | 1421篇 |
1987年 | 1227篇 |
1985年 | 3900篇 |
1984年 | 4910篇 |
1983年 | 3416篇 |
1982年 | 3897篇 |
1981年 | 3625篇 |
1980年 | 3232篇 |
1979年 | 2970篇 |
1978年 | 2587篇 |
1977年 | 1955篇 |
1976年 | 2176篇 |
1975年 | 1634篇 |
1974年 | 1433篇 |
1973年 | 1284篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Yancu Hertzanu M.D. Menachem Hirsch Louis Goleman 《Cardiovascular and interventional radiology》1987,10(4):230-233
Two unusual cases of delayed synthetic graft complications resulting from manufacturing defects of knitted Dacron are presented.
Computed tomography appears to be a suitable noninvasive alternative examination to angiography in this condition. 相似文献
992.
目的 评价第三代CT定量诊断胆囊结石的准确率及敏感性.方法 120例胆囊结石的病人在使用第三代CT检查后7天内施行胆囊切除手术,术后剖开胆囊,进行结石计数和最大结石的最大径线测量.结果 120例胆囊结石患者,其中87例有确切结石计数和测量结果(72.5%);33例CT检查未发现胆囊结石(27.5%).CT图像中显示的胆囊结石的数目:均数±标准差=3±15个;范围为2~82个与手术发现的数目:均数±标准差=68±316个;范围为2~1326个,两者比较具有显著性差异(P<0.001).CT图像发现的胆囊内最大结石的最大径线值:均数±标准差=1.08±1.06cm,范围为0~2.4cm;与手术测量值均数±标准=1.68±0.14cm范围为0.67~3.1cm,两者比较有显著性差异(P<0.001).结论 用第三代CT进行胆囊结石的定量诊断不够准确,敏感性也有不足. 相似文献
993.
P. CURZEN 《Medical education》1987,21(6):498-504
A complete annual entry of 181 students were administered a questionnaire in which they were invited to make value judgements about all aspects of their 3-month course in obstetrics and gynaecology. The resulting performance indicators were used to compare individual staff and clinical firms. 相似文献
994.
Wheezing at 8 and 13 years: changing importance of bronchiolitis and passive smoking 总被引:2,自引:0,他引:2
A group of 153 children (51 with a history of bronchiolitis and 102 matched controls) were evaluated in a historical cohort study at a mean age of 8 years and again at 13 years to test the primary hypothesis that mild bronchiolitis, far more common than severe (hospitalized) bronchiolitis, predicts wheezing. A secondary hypothesis was that passive smoking also predicts wheezing. Many potentially confounding variables such as family history of asthma were controlled in analyses. Analysis at 13 years produced results that were not anticipated from previous analysis of interviews at age 8. Although mild bronchiolitis was a powerful predictor of wheezing at age 8 years, it was no longer a strong predictor of wheezing at age 13 in either bivariate or multivariate analysis. Although epidemiologic studies, by their nature, cannot prove causality, findings are consistent with the hypothesis that sequelae often follow mild bronchiolitis but diminish during childhood. Maternal smoking was a powerful predictor of wheezing at age 13 in bivariate analysis (Kendall's Tau B = 0.19, P less than 0.01) and in multivariate analysis (odds ratio = 2.67, P less than 0.01). In children at highest risk for wheezing, males with a family history of asthma, multivariate analysis suggested that maternal smoking is associated with an increase in wheezing from 36% to 60%. We conclude that passive smoking, previously identified as a risk factor in this population for both bronchiolitis in infancy and wheezing at age 8, is a risk factor for wheezing-associated morbidity throughout the childhood years. 相似文献
995.
William H. Cormier Akira Otani L. Sherilyn Cormier 《Cognitive therapy and research》1986,10(1):95-108
The present study assessed the effects of problem-solving (D'Zurilla & Goldfried, 1971) training on two problem-solving tasks. Sixty-one subjects were assigned randomly to and trained in one of the following groups: general orientation (GO)-problem definition (PD)-generation of alternatives (GA)-decision making (DM), GO-PD-GA, GO-PD-DM, GO-GA-DM, GO, and a control group. The six groups did not differ significantly at pretesting on the measures of selecting the best alternative solution and describing problem-solving behaviors used to solve problems. Training was significantly effective on selecting the best alternative solution for all groups compared with the control group at the time of posttesting. The GO-PD-GA-DM and GO-PD-DM groups described significantly more problem-solving behaviors than the GO-PD-GA, GO-GA-DM, and GO groups. All five treatment groups performed significantly better than the control group at the time of post-testing. At follow-up 1 month after posttesting, groups trained with the PD component selected significantly better alternatives than the groups without PD training. Groups trained with the DM component described significantly more problem-solving behaviors at follow-up than the groups trained without the DM component. 相似文献
996.
本文对食管癌高、低发区食管癌患者和正常人,经MNNG诱导的DNA损伤修复功能进行了研究。实验采用外周血淋巴细胞培养的方法。每组又分为对照组及MNNG诱导组。样品以~3H-TdR标记后经液闪仪计数法进行检测。结果发现,低发区正常人经MNNG诱导的DNA损伤修复功能明显高于对照组,两个地区食管癌患者修复能力均低于正常人,与地区无关。 相似文献
997.
当代大学生手淫行为比较普遍,很多大学生在上大学之前就养成了难以自控的手淫习惯。大学生手淫既影响了他们的身心健康,对他们在校园里健康成长成材也构成了严重的威胁。从思想与心里教育角度引导大学生正确对待手淫,促使他们养成积极健康的生活习惯,对他们将来人生的健康发展及营造和谐的校园风气具有重要的作用。文章论述了当代大学生手淫的根源、手淫危害、诱发因素、手淫动机及预防、矫治措施。 相似文献
998.
999.
根据由精氨酸-甘氨酸-天冬氨酸组成的肽能抑制血小板聚集的机制,设计并合成了[5-(4-甲脒-苄基)-2,4-二氧代-咪唑烷-3-基]-乙酰基-L-天冬氨酰-L-缬氨酸(9)。生物试验结果表明:(9)抑制血小板聚集作用最强,其活性以IC_(50)值相比,强于类似物。 相似文献
1000.
Onelio Geatti Brahm Shapiro Pier Giuseppe Orsolon Gianni Proto Ugo Paolo Guerra Francesco Antonucci Daniele Gasparini 《European journal of nuclear medicine and molecular imaging》1994,21(1):17-22
Technetium-99m methoxyisobutylisonitrile (MIBI), like thallium-201, has recently been introduced as a myocardial perfusion agent and is now also showing very promising results in parathyroid scintigrapy. The results of 201Tl/99mTc-pertechnetate and 99mTc-MIBI/99mTc-pertechnetate subtraction scintigraphy, ultrasonography and computed tomography are presented in a series of 43 patients operated on for hyperparathyroidism. All four imaging modalities were confirmed to be reliable, scintigraphy being the most accurate. Sensitivities ranged from 81% to 95%, that of 99mTc-MIBI being the highest. Moreover this tracer, which has more favourable physical and also biochemical properties, yielded images of superior quality. This allowed localization of the lesion by visual inspection only in as many as 86% of the patients with positive 99mTc-MIBI/99mTc-pertechnetate subtraction scintigraphy. We believe that the higher sensitivity, superior image quality and lower cost of 99mTc-MIBI imaging will make 99mTc-MIBI the new radiopharmaceutical of choice for parathyroid scintigraphy (when one takes into account the stability of labelling with large activities it is possible to perform three or four cardiac studies together with one parathyroid scintigraphic examination using one lyophililzed vial). 相似文献