全文获取类型
收费全文 | 65810篇 |
免费 | 6129篇 |
国内免费 | 1389篇 |
专业分类
耳鼻咽喉 | 849篇 |
儿科学 | 1685篇 |
妇产科学 | 1143篇 |
基础医学 | 7122篇 |
口腔科学 | 1391篇 |
临床医学 | 7604篇 |
内科学 | 10345篇 |
皮肤病学 | 906篇 |
神经病学 | 5378篇 |
特种医学 | 2853篇 |
外国民族医学 | 4篇 |
外科学 | 7971篇 |
综合类 | 6526篇 |
现状与发展 | 8篇 |
一般理论 | 34篇 |
预防医学 | 6741篇 |
眼科学 | 1396篇 |
药学 | 5616篇 |
36篇 | |
中国医学 | 2040篇 |
肿瘤学 | 3680篇 |
出版年
2023年 | 416篇 |
2022年 | 900篇 |
2021年 | 1416篇 |
2020年 | 1038篇 |
2019年 | 929篇 |
2018年 | 1024篇 |
2017年 | 1047篇 |
2016年 | 989篇 |
2015年 | 1360篇 |
2014年 | 1761篇 |
2013年 | 2645篇 |
2012年 | 3849篇 |
2011年 | 3994篇 |
2010年 | 3004篇 |
2009年 | 2592篇 |
2008年 | 3472篇 |
2007年 | 3602篇 |
2006年 | 3367篇 |
2005年 | 2901篇 |
2004年 | 2549篇 |
2003年 | 2310篇 |
2002年 | 2140篇 |
2001年 | 2005篇 |
2000年 | 1926篇 |
1999年 | 1485篇 |
1998年 | 568篇 |
1997年 | 535篇 |
1996年 | 497篇 |
1995年 | 472篇 |
1994年 | 415篇 |
1992年 | 1164篇 |
1991年 | 1180篇 |
1990年 | 1094篇 |
1989年 | 1098篇 |
1988年 | 908篇 |
1987年 | 1035篇 |
1986年 | 957篇 |
1985年 | 974篇 |
1984年 | 765篇 |
1983年 | 625篇 |
1982年 | 396篇 |
1980年 | 372篇 |
1979年 | 700篇 |
1978年 | 524篇 |
1977年 | 447篇 |
1976年 | 459篇 |
1975年 | 398篇 |
1974年 | 520篇 |
1973年 | 455篇 |
1972年 | 383篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
A retrospective analysis of the results of 27,801 cervical smears from one year in a community laboratory was undertaken. This represented 23,820 individual patients. Abnormalities were seen in 9.3% of patients. Three point seven percent of patients had benign abnormalities, 5.5% had cervical intraepithelial neoplasia and 0.1% had major abnormalities. The incidence of cervical epithelial abnormality was highest in the 15-34 age group but major abnormalities were seen most often in the 55+ age group. Human papillomavirus was more commonly seen in the youngest age group. The presence of inflammation was reported in 65% of the smears. Thirty percent of smears had no endocervical cells and 0.6% were grossly inadequate. Fifteen percent of patients had repeat smears and 3% of total smears were judged unnecessary. Forty two point six percent of patients less than 55 years of age in the laboratory population base had a smear but only 7.9% of those over 55. 相似文献
42.
Nursing diagnosis as a critical component of the nursing process provides a common taxonomy to describe problems that nurses can treat and is a convenient, logical way to reference nursing standards. Theory is translated into practice with the use of population-specific prototype care guides and a written orders system. Nurses in leadership are responsible for providing the necessary resources to promote professional growth and facilitate desired change. Recommendations to assist with the implementation of nursing diagnosis are identified in Table 1. The system is dependent on staff nurses' professional commitment to learning and willingness to actively participate in change. Involvement of staff nurses continues to be a critical factor in the improvement of nursing practice. 相似文献
43.
Previous studies have shown that stimulation of adrenergic receptors in the brain increases the expression of the immediate early gene (IEG), c-fos, in vivo (Mol. Brain Res., 6(1989) 39-45). The present study was undertaken to determine whether this also holds for other IEGs which have been shown to be activated in brain cell culture by adrenergic agonists. Both yohimbine injection and stressful stimulation, two treatments causing brain norepinephrine (NE) release, were found to cause a parallel, transient activation of at least 5 IEGs (c-fos, nur77, tis-7, zif-268 and tis-21) in the rat cortex. Genes that are not immediate early (beta-actin, NGF and HSP70) were found not to be affected in the interval used (6 h). The responses were mediated predominantly by beta-adrenoceptors with some contribution from alpha 1 receptors. The parallel activation of multiple genes by noradrenergic receptors may enable the coding of different biochemical responses to the activation of different receptors. 相似文献
44.
报道了1,2-环己二胺异柠檬酸铂(Ⅱ)及1,2-环己二胺柠檬酸铂(Ⅱ)的合成及鉴定方法。抗癌试验表明前者在40及80mg/kg 剂量下对小鼠 L1210、P388及S180均有明显的抑瘤作用,且有部分动物可治愈;后者对 L1210也有明显的抑瘤作用,但较前者为弱。 相似文献
45.
80例健康青年分别经针刺或艾灸肺俞穴后的肺功能变化 总被引:3,自引:0,他引:3
目的:探讨针刺与艾灸肺俞穴对健康人肺功能的影响。方法:我们选择了20-22岁健康男性80例,随机分为针刺组和艾灸组各40例,于针刺,艾灸前和针刺,艾灸后10min测试用力肺活量(FVC),用力呼气量(FEV1.0),最大呼气中段流速(MMF),最大呼气流量(PEFR),75%,50%,25%肺活量时的最大呼气流速(V75,V50,V25),结果:显示经针刺和艾灸肺俞穴后2组FVC,FFV1.0均显著增加,P<0.05,2组间比较针刺组FVC明显高于艾灸组,P<0.05,而且艾灸组MMF,V25亦显著降低P<0.05,结论:健康人经针刺和艾灸肺俞穴后均可使大气道阻力减少,肺容量增加,提示一定量的艾燃烧后的烟雾可使健康人肺功能受到影响,使肺的小气道收缩,出现阻塞性改变。 相似文献
46.
The family physician should follow the small premature infant in the neonatal intensive care center and review the baby's problems and risk factors. In the office, special attention is required in monitoring the infant. Proper hospital and office care greatly improve the prognosis. 相似文献
47.
Cocaine-treated rats acquired a preference for cocaine-associated contextual stimuli (CS) relative to saline-injected control rats. However, when animals were given repeated tests for conditioned place preference intermittent between conditioning trials, they displayed an attenuation in strength of conditioning. This attenuation was not due to pharmacologic tolerance (Experiment 1), but rather reflected a disruption in learning due to exposure to the CS alone (Experiment 2). Like other examples of classical conditioning, the strength of the conditioned response (CR) as assessed by the conditioned place preference model may be influenced by partial reinforcement. 相似文献
48.
Distance learning in a school nurse credential program. 总被引:4,自引:0,他引:4
Distance learning, which encompasses many methodologies, is becoming a more readily available educational alternative. Because there are a limited number of school nurse credential programs and the demand for school nurses is increasing, distance learning may be a viable method of instruction. This article describes the authors' experiences organizing and presenting distance learning courses to five remote sites for students in a university school nurse credential program. After numerous inquiries, potential students from several areas were surveyed, and arrangements were made with universities in those areas to receive two-way audio and video transmissions of two seminar courses; later, two clinically oriented courses in the school nurse program. Students were able to complete their program requirements by taking equivalent course work at their local universities. Perceptions of students and the instructor, course evaluation, and practical suggestions are shared. Guidelines for potential students about selecting quality distance education programs are also noted. 相似文献
49.
Pediatric procedures in the Emergency Department typically involve techniques for stabilization, evaluation, and treatment of the child. This article considers indications and techniques for vascular access, lumbar puncture, arterial lines, pulse oximetry, and urine collection. Multiple routes of medication administration and pain management modalities also are reviewed. 相似文献
50.