全文获取类型
收费全文 | 6785篇 |
免费 | 241篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 97篇 |
妇产科学 | 47篇 |
基础医学 | 1194篇 |
口腔科学 | 36篇 |
临床医学 | 1311篇 |
内科学 | 349篇 |
皮肤病学 | 21篇 |
神经病学 | 738篇 |
特种医学 | 101篇 |
外科学 | 719篇 |
综合类 | 818篇 |
预防医学 | 841篇 |
眼科学 | 10篇 |
药学 | 633篇 |
1篇 | |
中国医学 | 57篇 |
肿瘤学 | 89篇 |
出版年
2024年 | 12篇 |
2023年 | 37篇 |
2022年 | 136篇 |
2021年 | 181篇 |
2020年 | 140篇 |
2019年 | 94篇 |
2018年 | 91篇 |
2017年 | 140篇 |
2016年 | 192篇 |
2015年 | 156篇 |
2014年 | 380篇 |
2013年 | 427篇 |
2012年 | 431篇 |
2011年 | 476篇 |
2010年 | 353篇 |
2009年 | 408篇 |
2008年 | 429篇 |
2007年 | 420篇 |
2006年 | 336篇 |
2005年 | 247篇 |
2004年 | 204篇 |
2003年 | 161篇 |
2002年 | 120篇 |
2001年 | 76篇 |
2000年 | 68篇 |
1999年 | 58篇 |
1998年 | 59篇 |
1997年 | 77篇 |
1996年 | 98篇 |
1995年 | 177篇 |
1994年 | 133篇 |
1993年 | 112篇 |
1992年 | 108篇 |
1991年 | 110篇 |
1990年 | 90篇 |
1989年 | 67篇 |
1988年 | 22篇 |
1987年 | 16篇 |
1986年 | 21篇 |
1985年 | 15篇 |
1984年 | 17篇 |
1982年 | 16篇 |
1981年 | 18篇 |
1980年 | 20篇 |
1979年 | 16篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1975年 | 13篇 |
1974年 | 12篇 |
1972年 | 16篇 |
排序方式: 共有7077条查询结果,搜索用时 31 毫秒
61.
Ahmadiyeh N Churchill GA Solberg LC Baum AE Shimomura K Takahashi JS Redei EE 《Behavior genetics》2005,35(2):189-198
A genome-wide scan was carried out on a segregating F2 population of rats derived from reciprocal intercrosses between two inbred strains of rats, Fisher 344 (F344) and Wistar Kyoto (WKY) that differ significantly in their behavioral coping responses to stress measured by the defensive burying (DB) test. The DB test measures differences in coping strategies by assaying an animals behavioral response to an immediate threat. We have previously identified three X-linked loci contributing to the phenotypic variance in behavioral coping. Here we report on six significant autosomal quantitative trait loci (QTL) related to different behaviors in the DB test:one for the number of shocks received, three for number of prod approaches, one for latency to bury, and one pleiotropic locus affecting both approach and latency. These QTL contributing to different aspects of coping behaviors show that the effect of genotype on phenotype is highly dependent on lineage. The WKY lineage was particularly influential, with five out of the six QTL affecting coping behavior only in rats of the WKY lineage, and one locus affecting only those in the F344 lineage. Thus, epigenetic factors, primarily of WKY origin, may significantly modulate the genetic contribution to variance in behavioral responses to stress in the DB test. 相似文献
62.
警察的孤独感状况及其相关因素分析 总被引:3,自引:0,他引:3
目的:探讨警察的孤独感状况及其与心理健康、应对方式、社会支持的相关关系。方法:采用UCLA孤独量表,SCL-90症状自评量表,TCSQ特质应对方式问卷和PsSS领悟社会支持量表。对某市区公安分局884名公安干警进行调查。结果:派出所警察的孤独感明显高于机关干警。50—59岁组警察的孤独感明显低于其他年龄段。警察的孤独感与警种、积极应对、社会支持显著负相关,与消极应对及SCL-90得分显著正相关。年龄、婚姻状况、应对方式、社会支持以及SCL-90总分是影响警察孤独感的显著因素。结论:警察的孤独感程度较高。50岁以下的派出所民警,尤其是婚姻不稳定者是孤独敏感群体。警察的孤独感与应对方式、社会支持及心理健康水平相互影响。 相似文献
63.
初中生自我中心与父母教养方式的相关研究 总被引:1,自引:0,他引:1
鹿美丽 《中国健康心理学杂志》2008,16(2):199-200
目的探索初中生自我中心与父母教养方式的关系。方法运用自我中心与父母教养方式量表对276名初中学生进行调查。结果①初中生自我中心在性别、是否独生上均不存在显著差异。②初中生假想观众与父母过分干涉、过分保护呈显著正相关。③初中生的个人神话水平与父、母情感温暖理解,父亲偏爱有显著正相关。结论国内初中生自我中心与其父母教养方式之间存在密切关系。 相似文献
64.
目的对研究获得的强迫症疾病行为特征探索其精神病理学机制。方法以符合CCMD-Ⅱ的门诊强迫症患者50例为对象,选取非精神科病人50例组成对照,应用“强迫症疾病行为特征量表(OBPS)”,确定其有无强迫症疾病行为。同时调查研究组与对照组的人格特质、偶发事件、应对策略等方面,研究这些因素在疾病发生、发展中的作用。结果①研究组全部符合李一高量表的疾病行为特征,积分明显高于对照组(t=26.480,P〈0.01);②强迫症患者人格当中的强迫质偏高,积分明显高于对照组(t=15.93,P〈0.01);③研究组中绝大多数患者存在偶发事件,而对照组中偶发事件的发生率低于研究组(X^2=21.374,P〈0.01);④应对策略特征方面研究组不成熟应对方式的应用明显多于对照组。结论强迫神经症形成中人格特质作为基础,偶发事件起到启动对“不完全的恐怖”,错误的应对策略不断强化病感,促进疾病形成。李一高强迫症疾病行为理论的3项内容,特征性的反映了强迫症的疾病行为。 相似文献
65.
铁路警察和监狱警察应对方式比较 总被引:1,自引:0,他引:1
目的了解铁路警察和监狱警察应对方式的差异。方法采用应对方式问卷对87名广州铁路警察进行调查,并以87名监狱警察作为对照组。结果铁路警察的主要应对方式是解决问题,与监狱警察相类似,但铁路警察的退避、自责得分较高(P〈0.05)。女性和青年的应对方式无差异(P〉0.05),而男性和中年铁路警察的自责、退避得分较高(P〈0.05)。对铁路警察的应对方式进行回归分析发现他们的应对方式与其待遇评价、警龄、是否想转行和婚姻状况密切相关。结论铁路警察的应对方式是积极的,退避和自责可能是与铁路警察职业相适应的应对方式调整。 相似文献
66.
目的探讨在押男性犯罪嫌疑人与正常人群大五人格、应对方式的差异。方法对78名在押男性犯罪嫌疑人(实验组)及54名对照组男性(对照组)进行问卷调查。结果①利他性与道德感维度差异显著;②实验组积极应对显著低于正常组,但消极应对差异不大;⑧实验组与对照组在人格与心理健康的相互关系上具有不同的特点。结论青年男性在押犯罪嫌疑人与正常青年男性在大五人格、应对方式上存在差异。 相似文献
67.
Christer Halldin Karl-Olof Schoeps Sharon Stone-Elander Fritz-Axel Wiesel 《European journal of nuclear medicine and molecular imaging》1987,13(6):288-291
The synthesis of d-and l-(1-11C)tyrosine, starting with 11C-cyanide, is reported. dl-(1-11C)Tyrosine was prepared by the Bücherer-Strecker reaction, from carrier added 11C-cyanide with an incorporation of 80% in 20 min. The isolation of the pure d- and l-amino acid isomers from the enantiomeric mixture was accomplished within 15 min by preparative HPLC using a chiral stationary phase and a phosphate buffer as the mobile phase. Typically, the total synthesis time was 50 min (including purification) from end of trapping of 11C-cyanide, with a radiochemical yield of d- and l-amino acid of 40%–60%. The d- and l-(1-11C)tyrosine were both obtained optically pure, with a carrier added specific activity of 0.3–0.5 Ci/mmol and a radiochemical purity better than 99%. The 11C labelled l-tyrosine was used in an in vivo study in the human brain using positron emission tomography (PET). 相似文献
68.
T. Kato M. Katsuyama N. Karai A. Hirose M. Nakamura J. Katsube 《Naunyn-Schmiedeberg's archives of pharmacology》1986,332(3):243-246
Summary The effect of l-threo-DOPS on the reserpine-induced ptosis in mice and its modification by imipramine, a norepinephrine (NE) uptake inhibitor, or nialamide, a monoamineoxidase inhibitor, were studied.Intraperitoneal (i.p.) injection of l-threo-DOPS (800 mg/kg) significantly reduced the severity of the ptosis. This reversal of the ptosis by l-threo-DOPS was markedly potentiated by i.p. injection of either imipramine (2.5 mg/kg) or nialamide (30 mg/kg). Response to l-threo-DOPS was also significantly potentiated by intracerebroventricular (i.c.v.) injection of imipramine (10 g). On the other hand, this treatment with imipramine (10 g, i.c.v.) also significantly potentiated the reversal of the ptosis by NE (20 g, i.c.v.), but the reversal by the subcutaneous (s.c.) injection of NE (1 and 3 mg/kg) was not affected.Reserpine (5 mg/kg, i.p.) markedly decreased the brain content of NE in mice, whereas l-threo-DOPS (400 mg/kg, i.p.) slightly restored it. Moreover, by the pretreatment with nialamide (30 mg/kg, i.p.), l-threo-DOPS produced a significant increase in the brain content of NE in reserpinetreated mice.These results suggested that l-threo-DOPS was capable of reversing the reserpine-induced ptosis due to the formation, at least in part of (–)-NE at the synaptic sites of central noradrenergic neurons. 相似文献
69.
The analgesic ED50 values of some classical morphine congeners (morphine, methadone, fentanyl, azidomorphine) in the rat and mouse tail-flick tests were found to be similar. However, several synthetic derivatives of the natural enkephalins were more potent in mice than in rats. (These analogs contain d-amino acid in position 2 and d- or l-sulfonic (or phosphonic) acid residue in position 5). -Endorpin, d-Met2, Pro5-enkephalinamide and two partial agonists showed intermediate interspecies relative potencies. According to the data obtained, similar opiate receptors might mediate the analgesic action of classical opiates in rats and in mice. However, the opiate receptors responsible for the antinociceptive effects of the above mentioned enkephalin analogues must be dissimilar in the two species examined. The results are discussed in terms of the role of - and -receptors in mediation of the analgesic effect induced by different types of opioids. 相似文献
70.
Summary Several compounds have been shown to antagonize the excitation of single neurons produced by excitatory amino acids. This study was designed to determine the effectiveness of these compounds in antagonizing the hypermotility response to excitatory amino acids after intraaccumbens administration. Of the putative antagonists tested, D-aminoadipic acid, diaminopimelic acid and glutamic acid diethyl ester all showed significant inhibitory effects on excitatory amino acid-induced hypermotility while 2-amino-5-phosphonovaleric acid, -D-glutamylglycine, 2-amino-4-phosphonobutyric acid and cis-2,3-piperidine dicarboxylic acid were ineffective. D-Aminoadipic acid decreased N-methyl-aspartic acid-induced hypermotility while having no significant effect on the hypermotility responses induced by kainic or quisqualic acids. Diaminopimelic acid markedly decreased N-methyl-aspartic acid- and kainic acid-induced hypermotility but was totally ineffective on quisqualic acid-induced hypermotility. In contrast to D-aminoadipic acid, glutamic acid diethyl ester antagonized the increase in motility produced by kainic and quisqualic acids but not that produced by N-methyl-aspartic acid. The above data suggests that N-methyl-aspartic acid and quisqualic acid may produce their motor effects through the activation of two different receptors in the nucleus accumbens while kainic acid may mediate its hypermotility response through both N-methyl-aspartic acid and quisqualic acid receptors. However, a third receptor type activated solely by kainic acid cannot be excluded at this time. 相似文献