全文获取类型
收费全文 | 6033篇 |
免费 | 274篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 91篇 |
妇产科学 | 53篇 |
基础医学 | 831篇 |
口腔科学 | 31篇 |
临床医学 | 582篇 |
内科学 | 328篇 |
皮肤病学 | 11篇 |
神经病学 | 996篇 |
特种医学 | 76篇 |
外科学 | 867篇 |
综合类 | 859篇 |
一般理论 | 2篇 |
预防医学 | 604篇 |
眼科学 | 36篇 |
药学 | 681篇 |
2篇 | |
中国医学 | 184篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 97篇 |
2022年 | 169篇 |
2021年 | 177篇 |
2020年 | 175篇 |
2019年 | 236篇 |
2018年 | 304篇 |
2017年 | 167篇 |
2016年 | 162篇 |
2015年 | 155篇 |
2014年 | 395篇 |
2013年 | 393篇 |
2012年 | 314篇 |
2011年 | 408篇 |
2010年 | 260篇 |
2009年 | 276篇 |
2008年 | 315篇 |
2007年 | 275篇 |
2006年 | 273篇 |
2005年 | 208篇 |
2004年 | 190篇 |
2003年 | 123篇 |
2002年 | 123篇 |
2001年 | 104篇 |
2000年 | 93篇 |
1999年 | 79篇 |
1998年 | 79篇 |
1997年 | 60篇 |
1996年 | 51篇 |
1995年 | 49篇 |
1994年 | 50篇 |
1993年 | 27篇 |
1992年 | 31篇 |
1991年 | 29篇 |
1990年 | 34篇 |
1989年 | 24篇 |
1988年 | 25篇 |
1987年 | 22篇 |
1986年 | 18篇 |
1985年 | 29篇 |
1984年 | 23篇 |
1982年 | 27篇 |
1981年 | 27篇 |
1979年 | 30篇 |
1978年 | 24篇 |
1977年 | 19篇 |
1976年 | 24篇 |
1975年 | 28篇 |
1974年 | 31篇 |
1973年 | 27篇 |
1972年 | 15篇 |
排序方式: 共有6354条查询结果,搜索用时 15 毫秒
11.
Maria G. Genkova-Papazova Maria B. Lazarova-Bakarova 《European neuropsychopharmacology》1996,6(4):285-290
Deficit in active and inhibitory avoidance behaviour has been found in pentylenetetrazole (PTZ)-kindled rats. This supports the view that memory deficit is an integral part of epilepsy. In the present study we examined the effect of the nootropic drugs piracetam and fipexide on memory deficit induced by PTZ-kindling in shuttle-box- and step-down-trained rats. The retention in piracetam- and fipexide-treated animals was significantly improved compared to the kindled controls. The mechanisms of action of the two drugs are considered. The favourable effects of nootropic drugs in cases of amnesia provoked by PTZ-kindling might be of interest in clinical practice. 相似文献
12.
Reviewing the definition of "elderly" 总被引:1,自引:0,他引:1
Hajime Orimo Hideki Ito Takao Suzuki Atsushi Araki Takayuki Hosoi Motoji Sawabe 《Geriatrics & Gerontology International》2006,6(3):149-158
Conventionally, "elderly" has been defined as a chronological age of 65 years old or older, while those from 65 through 74 years old are referred to as "early elderly" and those over 75 years old as "late elderly." However, the evidence on which this definition is based is unknown. We have attempted to review the definition of elderly by analyzing data from long-term longitudinal epidemiological studies, and clinical and pathological studies that have been accumulated at the Tokyo Metropolitan Geriatric Hospital and the Tokyo Metropolitan Institute of Gerontology. Our recommendation might be a starting point in developing a strategy for a successful society by reviewing the definition of elderly based on comprehensive evidence in all aspects of social, cultural and medical sciences. 相似文献
13.
JOSEPH ROCHFORD ANANDA P SEN ISABELLE ROUSSE SHARON A WELNER 《Brain research bulletin》1996,41(5):313-317
Latent inhibition (LI) is a reduction in the rate of acquisition of a Pavlovian conditioned response that results from prior nonreinforced preexposure to a conditioned stimulus (CS). LI has been suggested to reflect the operation of mechanisms involved in stimulus selection for subsequent cognitive processing. The present experiment was conducted to assess the effect of bilateral lesions of the nucleus basalis magnocellularis (NBM) on LI employing a conditioned emotional response paradigm. Bilateral lesions of the NBM were produced by administration of 0.12 M quisqualic acid and resulted in decreased cortical acetylcholinesterase staining, as well as a 40% reduction in cortical choline acetyltransferase activity. Following lever press training, preexposed animals received 40 presentations of a 60-s tone CS. Nonpreexposed animals received no tone presentations. Acquisition of conditioned suppression was then assessed over the course of 4 tone-shock (0.6 mA, 0.5 s) pairings. Control, preexposed animals displayed a retarded rate of acquisition in comparison to nonpreexposed controls, thereby demonstrating that the parameters used in the present experiment produced LI. In contrast, lesioned animals preexposed to the CS acquired conditioned suppression as readily as non-preexposed lesioned animals. However, the acquisition of conditioned suppression in both lesioned groups was found to be similar to that displayed in the preexposed control group. This pattern of results was interpreted as being attributable to a lesion-induced impairment in the ability to maintain stimulus processing, rather than a deficit in the ability to filter a stimulus. Copyright © 1996 Elsevier Science Inc. 相似文献
14.
John T. Pardeck John W. Murphy Karen A. Callaghan 《Early child development and care》1994,97(1):67-72
This article suggests that the United States educational system needs significant changes. The goal of the article is to present a basic educational philosophy that would facilitate this reform. Specifically, education should be viewed as not only a means to an end that teaches basic skills for employment, but also as a process that enhances social development and self-actualization. Recommendations are offered to achieve this important goal. 相似文献
15.
党的十六大所提出的全面建设小康社会,是一个包括政治、经济、文化、环境乃至国民素质的综合概念。它特别要求国民具有健全的环境意识,良好的环境伦理道德和高尚的环境道德行为。作为担负着提高全体国民环境素质和培养中小学环境教育教师和地方环境建设服务三重使命的高师地理学科,面临着其环境教育的课程设置、教材建设和教师队伍建设等不可回避的课题,有必要进行深入探索。 相似文献
16.
17.
d-Amphetamine, 4-OH amphetamine, and epinephrine have been shown in many behavioral studies to facilitate memory when given post-training. The effect of these drugs on the maintained discharge of cells in the locus coeruleus (LC) was investigated using a route of administration (intraperitoneal) and a log-dose range of these drugs comparable to those used in the behavioral experiments.d-Amphetamine profoundly suppressed maintained discharge: an inhibitory effect was observed at every dose (0.1, 1.0, 10.0 mg/kg). In contrast, only the highest dose of 4-OH amphetamine (8.2 mg/kg) inhibited activity in the LC, and this effect was a modest one. Unlike the amphetamines, epinephrine (500 μ/kg) elevated maintained discharge. These results are discussed in the contex of the hypothesized involvement of the LC in the enhancement of memory by these drugs. 相似文献
18.
Research on the neurobiology of learning and memory has been guided by two major theories: (i) memory as a psychological process and (ii) memory as a change in synaptic neural connectivity. It is not widely recognised that not only are these theories different but, moreover, they are fundamentally incompatible. Confusion concerning basic concepts in the learning and memory field in mammals has lead to the creation of an extensive but often inconclusive experimental literature. However, one important conclusion suggested by recent work in this field is that experience-dependent changes in neural connectivity occur in many different brain systems. Particular brain structures, such as the hippocampus, do not play any uniquely important role in experience-dependent behavior. Research in learning and memory can be best pursued on the basis of biological studies of animal behavior and a cellular approach to brain function. 相似文献
19.
To increase preschoolers' science and mathematics learning experiences both within and outside the classroom, we developed age-appropriate materials containing general questions and instructions that teachers and parents could use when interacting with their students and children. The questions and instructions were related to a specific science or mathematics skill (e.g., classifying), but were general enough so that they could be applied to a variety of situations. Observations of three classrooms and interviews with the classroom teachers and aides, and the parents of the children in the classrooms suggested that use of these materials was beneficial to the children, teachers, and parents, and resulted in increasing the amount of science and mathematics activities and discussions in two of the classrooms as well as outside the classrooms. 相似文献
20.
目的提出对学习策略和教学方式的改进建议。方法测试口腔医学生的场依存/独立认知风格,并用统计学方法分析其与口腔正畸学学习成绩的关系。结果①场独立认知风格是口腔医学专业学生认知风格的主体;②不同性别口腔医学专业学生的场依存/独立认知风格无显著性差异;③学生场依存/独立认知风格与口腔正畸学理论考试成绩有负相关倾向,与口腔正畸学实习操作成绩有正相关倾向。结论学习策略和教学方式因受认知风格的影响而制约学生学习的效果。 相似文献