首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8143篇
  免费   498篇
  国内免费   63篇
耳鼻咽喉   17篇
儿科学   128篇
妇产科学   76篇
基础医学   1362篇
口腔科学   78篇
临床医学   1859篇
内科学   402篇
皮肤病学   36篇
神经病学   828篇
特种医学   115篇
外科学   958篇
综合类   767篇
预防医学   969篇
眼科学   11篇
药学   637篇
  2篇
中国医学   55篇
肿瘤学   404篇
  2024年   15篇
  2023年   91篇
  2022年   148篇
  2021年   197篇
  2020年   234篇
  2019年   217篇
  2018年   189篇
  2017年   219篇
  2016年   254篇
  2015年   242篇
  2014年   400篇
  2013年   687篇
  2012年   459篇
  2011年   465篇
  2010年   374篇
  2009年   451篇
  2008年   433篇
  2007年   443篇
  2006年   357篇
  2005年   291篇
  2004年   246篇
  2003年   206篇
  2002年   160篇
  2001年   139篇
  2000年   108篇
  1999年   93篇
  1998年   92篇
  1997年   116篇
  1996年   121篇
  1995年   186篇
  1994年   163篇
  1993年   132篇
  1992年   134篇
  1991年   135篇
  1990年   106篇
  1989年   82篇
  1988年   38篇
  1987年   25篇
  1986年   38篇
  1985年   20篇
  1984年   22篇
  1983年   12篇
  1982年   16篇
  1981年   17篇
  1980年   20篇
  1979年   16篇
  1977年   12篇
  1975年   12篇
  1973年   11篇
  1972年   15篇
排序方式: 共有8704条查询结果,搜索用时 31 毫秒
81.
The current study examined how individuals deal with genital herpes, a recurrent, incurable disease with a great psychological impact. An assessment battery composed of cognitive and problem-focused coping, attribution, and social support mechanisms was employed. These coping mechanisms were correlated with measures of psychological adjustment: self-esteem, depression, sexual adjustment, and amount upset by herpes. Subjects were 152 people with herpes recruited from self-help groups and people from the community who volunteered to participate in the study. Results supported several hypotheses derived from previous research on coping with life stressors. Cognitive coping mechanisms, especially negative thoughts, along with wishful thinking and characterological self-blame, were significant predictors of poor psychological adjustment. Social support was correlated with better psychological adjustment. In addition, the repeated use of disease management strategies was found to correlate with poor psychological adjustment. Further research in the area of coping with chronic illness is suggested.  相似文献   
82.
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   
83.
We examined the long term predictivity of heart rate reactivity (HRR) and its relation to cardiovascular and biochemical activity during rest and during tasks requiring active and passive coping. HRR was determined in 28 young men by measuring peak heart rate change to cold pressor one year after performing tasks eliciting active and passive coping. Heart rate change to cold pressor was significantly correlated with change to active coping (r= .65, p<.01) and to passive coping (r= .53, p<.01). Responses to the tasks were equivalent for Type A and B subjects. On the other hand, high HRRs were significantly more reactive than low HRRs with the effect being most apparent during active coping. HRR appeared to be a trait stable over one year which predicted enhanced cardiac, neuroendocrine, and neuromuscular response.  相似文献   
84.
Kittens were given differential early experience in order to compare an objective coping behavior with the result of an inescapable aversive experience. Separate groups of kittens were treated in a shock motivated runway task at either 4 or 12 weeks of age, by allowing one member of a weight matched sibling pair to acquire an escape behavior, while the other member was confined; a third subject served as a handled control. Escape behavior was significantly different for 4 and 12 week old subjects, since the older kittens reached a running asymptote within the first few shock trials. At 6 months of age, the subjects were tested for effects of differential early treatment; heart rate, respiration rate and amplitude, and somatic activity were measured during classical conditioning. While all groups gave evidence of acquisition in one or more response measures, only a potentiated heart rate response in 4 week kittens could be related to early experience. Heart rate did not differentiate escaping kittens from confined ones. Rather, heart rate was related to early treatment with shock, perhaps reflecting an increased tendency to react with a passive defensive response.  相似文献   
85.
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   
86.
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   
87.
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   
88.
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   
89.
The COVID-19 pandemic has focused health systems on supporting patients affected by this virus. Meanwhile in the community, many other contained patients could only use self-care strategies, especially in countries that have set up a long and strict containment such as France. The study aimed to compare coping strategies deployed by patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS; a poorly recognised syndrome) to those with better known and referenced chronic conditions. An online flash survey was conducted during the containment period in partnership with French Patients Organizations including ME/CFS national association. Therefore, ‘Brief COPE’ version of Lazarus and Folkman's Ways of Coping Check List has been adapted to the specificity of the containment. The survey was e-distributed in France from 15 April to 11 May 2020. Differences of coping strategies were analyzed using Wilcoxon–Mann–Withney test. Amongst 637 responses, 192 were complete, presenting a wide variety of diseases, including 93 ME/CFS. The latter have significantly different coping strategies than recognised diagnosed diseases patients: similar uses of emotion focused coping but less uses of seek social support and problem-focused copings. In conclusion, coping strategies are different for those who deal with the daily experience of ME/CFS, highly disabling chronic condition with diagnostic ambiguity, low degree of medical and social recognition and without treatment. Better understanding of those strategies is needed to provide the means for health promotion researchers, managers and clinicians, to accompany those patients.  相似文献   
90.
非自杀性自伤(NSSI)在各国青少年群体中均有很高的发生率,且其发生率正逐年上升,已成为现阶段全球公认的影响青少年身心健康的重大公共卫生问题之一,备受国内外广大专家、学者的关注与重视。然而,其发生机制尚不明确,目前的研究也正处于初级阶段。据目前研究显示,NSSI的影响因素主要有个体因素、环境因素和神经生物学因素。家庭作为青少年成长过程中最重要的外部环境,在青少年身心发展中起着至关重要的作用。良好的家庭环境能在一定程度上预防和减少青少年NSSI等风险行为的发生, 并可能成为未来早期干预工作的一个重要途径。本文拟对近年来国内外相关文献进行综述,为下一步研究家庭因素对青少年NSSI行为的影响提供思路,同时为临床干预和治疗提供参考。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号