全文获取类型
收费全文 | 21017篇 |
免费 | 1392篇 |
国内免费 | 287篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 524篇 |
妇产科学 | 205篇 |
基础医学 | 3662篇 |
口腔科学 | 368篇 |
临床医学 | 2099篇 |
内科学 | 1726篇 |
皮肤病学 | 149篇 |
神经病学 | 3960篇 |
特种医学 | 203篇 |
外国民族医学 | 1篇 |
外科学 | 521篇 |
综合类 | 1810篇 |
一般理论 | 1篇 |
预防医学 | 4510篇 |
眼科学 | 39篇 |
药学 | 2315篇 |
8篇 | |
中国医学 | 224篇 |
肿瘤学 | 330篇 |
出版年
2024年 | 75篇 |
2023年 | 334篇 |
2022年 | 719篇 |
2021年 | 997篇 |
2020年 | 769篇 |
2019年 | 628篇 |
2018年 | 578篇 |
2017年 | 668篇 |
2016年 | 713篇 |
2015年 | 681篇 |
2014年 | 1203篇 |
2013年 | 1625篇 |
2012年 | 1025篇 |
2011年 | 1177篇 |
2010年 | 850篇 |
2009年 | 890篇 |
2008年 | 926篇 |
2007年 | 891篇 |
2006年 | 833篇 |
2005年 | 665篇 |
2004年 | 545篇 |
2003年 | 518篇 |
2002年 | 456篇 |
2001年 | 349篇 |
2000年 | 274篇 |
1999年 | 262篇 |
1998年 | 215篇 |
1997年 | 201篇 |
1996年 | 173篇 |
1995年 | 164篇 |
1994年 | 147篇 |
1993年 | 128篇 |
1992年 | 138篇 |
1991年 | 132篇 |
1990年 | 114篇 |
1989年 | 120篇 |
1988年 | 121篇 |
1987年 | 99篇 |
1986年 | 148篇 |
1985年 | 247篇 |
1984年 | 242篇 |
1983年 | 174篇 |
1982年 | 213篇 |
1981年 | 200篇 |
1980年 | 195篇 |
1979年 | 181篇 |
1978年 | 127篇 |
1977年 | 139篇 |
1976年 | 130篇 |
1975年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
牛磺酸与大脑发育关系的初步探讨——牛磺酸与行为 总被引:6,自引:0,他引:6
本实验将断乳大鼠随机分成三组。补充0.6%牛磺酸组(ST组);未补充牛磺酸组(TF组);及5703大鼠常备膳组(5703组)。用水迷宫及食物偏爱性试验观察补充牛磺酸对大鼠学习、记忆能力的影响。结果表明,三组大鼠在水迷宫试验总潜伏期,总错误次数,无误率及持续时间四项指标上均存在高度显著差异。ST:TF P<0.01;ST:5703 P<0.01;5703:TF P<0.05。ST与TF在食物偏爱性试验上存在显著差异(P<0.05)。上述结果表明:牛磺酸与大脑发育有关,表现为补充了牛磺酸的大鼠在学习、记忆等方面的提高。而牛磺酸缺乏对幼鼠大脑及智力发育有不利影响,表现为学习、记忆能力的不足。 相似文献
82.
The effects of monoamine oxidase inhibitors (MAOIs) that selectively inhibit the MAO-A or MAO-B forms of MAO were studied in rats performing under a differential-reinforcement-of-low-rate 72-s (DRL 72-s) schedule of reinforcement. Clorgyline and CGP11305A, irreversible and reversible MAO-A inhibitors, respectively, increased the reinforcement rate, decreased the response rate, and enhanced temporal discrimination. The irreversible MAO-B inhibitor (–)-deprenyl did not produce similar effects. Pargyline did not increase the reinforcement rate at low doses that selectively inhibit MAO-B, but did increase the reinforcement rate at doses that inhibit MAO-A by more than 90%. The present results are in accord with clinical data demonstrating that MAO-A inhibitors are effective therapeutic agents in treating depression while MAO-B inhibitors are of questionable antidepressant efficacy. The present findings provide further evidence that the DRL 72-s schedule may be useful both as a screen for identifying new antidepressants and for investigating the neurochemical effects of antidepressant drugs that are responsible for their therapeutic effects. 相似文献
83.
背景 近年来,国内针对多病共存患者在分级诊疗背景下就医机构选择行为的研究较少,研究多病共存患者的就医机构选择行为有重要的现实意义。目的 以分级诊疗为视角,分析多病共存患者就医机构选择行为及其影响因素,为进一步落实分级诊疗制度和合理配置医疗资源提供研究参考。方法 采用随机抽样法,选取2019-06-01至2020-01-01在上海市杨浦区中心医院医疗联合体(上海市杨浦区中心医院和上海市杨浦区定海、延吉、长白社区卫生服务中心)就诊的多病共存患者为研究对象。采用自设问卷对其进行调查,收集多病共存患者的一般资料,了解其对分级诊疗政策的认知情况及实际遵守情况、在不同疾病控制状况下至社区卫生服务中心首诊的意愿,以及其选择就诊医疗机构时考虑的因素等。采用二分类Logistic回归分析多病共存患者此次因病就医是否选择至社区卫生服务中心首诊的影响因素。结果 共发放1 100份问卷,回收有效问卷1 072份,有效问卷回收率为97.45%。1 072例多病共存患者中,老年(≥60岁)多病共存患者占85.07%(912/1 072)。624例(58.21%)患者表示知晓分级诊疗制度;940例(87.69%)患... 相似文献
84.
"Necklace olfactory glomeruli" form unique components of the rat primary olfactory system 总被引:3,自引:0,他引:3
A distinct subset of rat primary olfactory neurons was identified immunohistochemically by means of a polyclonal antibody against human placental antigen X-P2 (hPAX-P2), an incompletely characterized substance found in all estrogen-biosynthetic organs. The subset of olfactory receptor cells was distributed widely over the olfactory epithelium with some degree of concentration on the dorsocaudal walls of nasal subcavities. The subset formed unique "necklace olfactory glomeruli," which were composed of seven to nine solitary glomeruli located in the caudal end of the olfactory bulb. One of them was located in the "modified glomerular complex" reported to be involved in rat suckling behavior. The projectional patterns of the necklace olfactory system, albeit diffuse, indicated some degree of spatial correspondence between zones of olfactory epithelium and specific glomeruli. Axons emanating from neighboring cells can project to several glomerular loci. From the necklace olfactory system, an average of 150-200 receptor cells were estimated to converge onto a single necklace glomerulus. 相似文献
85.
In many animal studies, acute treatment with the novel anxiolytic agent buspirone exhibits only minimal anxiolytic efficacy (i.e., increases in punished responding) when compared to benzodiazepines and barbiturates. The present studies examined the effects of acute pre-test challenges with buspirone in subjects receiving chronic post-test buspirone or saline treatments. Chronic post-test treatment with buspirone (4 mg/kg/day for 4 weeks, followed by 8 mg/kg/day for 12 weeks) did not significantly affect CSD behavior. Consistent with previous reports, acute pre-test administration of buspirone (0.125–2 mg/kg, IP) to subjects receiving chronic post-test saline treatment resulted in only a modest anti-conflict effect in the CSD paradigm (approximately ten shocks over control). In contrast, subjects chronically treated with buspirone exhibited a dramatically greater anti-conflict effect following acute challenge with buspirone (up to 40 shocks over control). These data are consistent with the hypothesis that the full anxiolytic efficacy of buspirone requires repeated administration. 相似文献
86.
Prevention of Postinfectious Asthma in Children by Reducing Self-Inoculatory Behavior 总被引:1,自引:0,他引:1
Cortey Donald L.; Gevirtz Richard; Nideffer Robert; Cummins Leo 《Journal of pediatric psychology》1987,12(4):519-531
Recent studies have shown that the spread of infectious nasalsecretions from hand-to-hand or hand-to-object, followed byself-inoculation is an efficient means of viral transmission.The present study was designed to investigate whether self-inoculationbehavior in asthmatic children could be reduced and, if so,whether this reduction would reduce the frequency of infectionand asthma. Sixteen subjects aged 4 to 8, all diagnosed withpostinfectious asthma, were assigned to a treatment (differentialreinforcement of other behavior and contingent education) orplacebo control condition. Results indicate that self-inoculatorybehavior, infection, and asthma were signjficantly reduced.These findings may indicate an important role for behavioralmedicine inpostinfectious asthma. 相似文献
87.
88.
Chronic experiments on cats showed that analgesics, in subanalgesic doses, not only exhibit an antinociceptive effect when accompanied by subthreshold stimulation of the mesencephalon, but also potentiate the analgesic action of central stimulation. Tranquilizers only facilitate the development of an analgesic effect during subthreshold mesencephalic stimulation. The possible reasons for differences in the action of these substances are discussed.Department of Pharmacology, I. P. Pavlov First Leningrad Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 1, pp. 36–41, January, 1978. 相似文献
89.
神经症的性压抑与心理因素的相关性研究 总被引:1,自引:0,他引:1
研究神经症患者潜在人格与性压抑和情绪的相关性.方法:对124例神经症患者进行了婚姻质量问卷(性生活、婚姻质量部份)、抑郁自评量表(以下简称SDS)、焦虑自评量表(以下简称SAS)及自编的性生活调查问卷、主题统觉测验(以下简称TAT)测评.结果:1、神经症伴性障碍组TAT潜在人格与对照组相比,在支配、性、援助、躯体社会攻击、财产破坏欲求、自我攻击、情绪变化欲求和情绪言语攻击性、躯体社会攻击、引诱、缺乏、丧失、灾害、丧失支持、躯体伤害压力上均较对照组显著增高,而成就欲求下降(P<005-001);与神经症无性障碍组相比,神经症伴性障碍组的成就、支配、教养、性欲求得分显著增高,情绪言语攻击欲求得分下降(P<001~005);2、神经症伴性障碍组的性生活质量低,性频度、性后快感均低.3、SDS、SAS与TAT中的负性欲求呈明显的相关性,性行为调查与婚姻质量量表中的性行为呈正相关.结论:神经症的性压抑与其潜在人格有密切的相关性. 相似文献
90.
妊娠中晚期暴露于可卡因对子代海马发育的影响 总被引:1,自引:0,他引:1
目的 建立妊娠中晚期暴露于可卡因的小鼠动物模型 ,研究可卡因对子代海马的发育是否具有影响以及这种影响在可卡因诱发的神经行为异常发病机理中可能所起的作用。方法 运用水迷宫方法观察可卡因对子鼠青春期空间辨别能力的影响 ,分别采用甲苯胺蓝染色技术和免疫组织化学结合图象分析技术观察海马中锥体细胞和神经胶质细胞的发育情况。结果 妊娠中晚期暴露于可卡因的小鼠子代在青春期海马锥体细胞极性紊乱 ,发育不良 ,未迁移到正常位置 ;神经胶质细胞数目减少。水迷宫结果显示可卡因可引起子代寻找平台的潜休期延长。结论 妊娠中晚期暴露于可卡因可引起子代青春期海马发育异常 ,这可能在可卡因引起子代空间辨别能力下降的发病机理中起着重要作用。 相似文献