全文获取类型
收费全文 | 1863篇 |
免费 | 120篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 76篇 |
妇产科学 | 43篇 |
基础医学 | 226篇 |
口腔科学 | 36篇 |
临床医学 | 524篇 |
内科学 | 196篇 |
皮肤病学 | 11篇 |
神经病学 | 281篇 |
特种医学 | 120篇 |
外科学 | 132篇 |
综合类 | 38篇 |
预防医学 | 152篇 |
眼科学 | 8篇 |
药学 | 82篇 |
肿瘤学 | 71篇 |
出版年
2021年 | 10篇 |
2020年 | 13篇 |
2019年 | 11篇 |
2018年 | 21篇 |
2017年 | 21篇 |
2016年 | 18篇 |
2015年 | 32篇 |
2014年 | 32篇 |
2013年 | 62篇 |
2012年 | 53篇 |
2011年 | 40篇 |
2010年 | 46篇 |
2009年 | 59篇 |
2008年 | 51篇 |
2007年 | 64篇 |
2006年 | 55篇 |
2005年 | 40篇 |
2004年 | 50篇 |
2003年 | 55篇 |
2002年 | 48篇 |
2001年 | 53篇 |
2000年 | 42篇 |
1999年 | 51篇 |
1998年 | 103篇 |
1997年 | 98篇 |
1996年 | 88篇 |
1995年 | 74篇 |
1994年 | 55篇 |
1993年 | 67篇 |
1992年 | 40篇 |
1991年 | 48篇 |
1990年 | 52篇 |
1989年 | 46篇 |
1988年 | 51篇 |
1987年 | 21篇 |
1986年 | 28篇 |
1985年 | 29篇 |
1984年 | 31篇 |
1983年 | 22篇 |
1982年 | 28篇 |
1981年 | 20篇 |
1980年 | 17篇 |
1979年 | 22篇 |
1978年 | 19篇 |
1977年 | 14篇 |
1976年 | 12篇 |
1975年 | 17篇 |
1974年 | 10篇 |
1973年 | 12篇 |
1971年 | 11篇 |
排序方式: 共有2020条查询结果,搜索用时 15 毫秒
991.
Keith McBurnett Adrian Raine Magda Stouthamer-Loeber Rolf Loeber Adarsh M Kumar Mahendra Kumar Benjamin B Lahey 《Neuropsychopharmacology》2005,57(10):1109-1116
BACKGROUND: Relations between stress hormones and antisocial behavior are understudied. METHODS: A subsample (n = 335) of at-risk males recruited in first grade for a longitudinal study were recruited at approximately 16 years of age for a laboratory study, including two psychological challenges: describing their worst experience on videotape, and a task in which a loud tone could be avoided. Measures of affect, urine, and saliva were collected multiple times before and after challenges. RESULTS: Negative affect increased following the worst-event challenge and decreased following the avoidance challenge. Mean conduct problems (CP) across ages 7-17 years were positively related to negative affect and inversely related to positive affect. CP were inversely related to post-challenge urinary epinephrine (E) levels when baseline E and potential confounds were controlled. Cortisol concentrations in saliva collected soon after the first challenge were positively related to CP in a post hoc subset of youths with extreme CP. CONCLUSIONS: Key findings A) associated persistent CP with more negative affectivity and less positive affectivity, B) replicated and extended prior findings of an inverse association of CP and urinary E, and C) suggested provocative hypotheses for future study relating CP, trauma history, trauma recall, and cortisol reactivity. 相似文献
992.
993.
B Cannella A H Cross C S Raine 《Laboratory investigation; a journal of technical methods and pathology》1991,65(1):23-31
The expression of a battery of adhesion-related molecules and cytokines was investigated by immunocytochemistry in the central nervous system (CNS) of SJL/J mice sensitized for experimental autoimmune encephalomyelitis (EAE). These molecules consisted of the ligands MECA-325, intercellular adhesion molecule-1, and major histocompatibility complex molecules I and II, plus the receptors lymphocyte function-associated antigen-1, CD8, and CD4. The cytokines comprised interferon-gamma and tumor necrosis factor-alpha. EAE was induced by the adoptive transfer of myelin basic protein-sensitized lymphocytes. MECA-325, a marker for murine high endothelial venules in lymph node tissue, was absent from normal CNS tissue, was expressed at low levels on venules 24 to 48 hours before the onset of clinical signs, rose to maximal levels during acute disease, decreased to preclinical levels during remissions, and rose again during relapses. Intercellular adhesion molecule-1, major histocompatibility antigen-I, and major histocompatibility antigen-II showed similar fluctuations around CNS vessels. The receptors lymphocyte function-associated antigen-1 and CD4 fluctuated in parallel with the above molecules, whereas CD8 remained at a similar low level. Interferon-gamma was present during the acute, remitting, and relapsing phases and was localized to inflammatory cells, whereas tumor necrosis factor occurred at low levels only. Thus, several molecules associated with lymphocyte traffic in lymphoid tissue are selectively expressed in a stage-specific manner within the target organ, the CNS, during EAE. This suggests that the CNS may act as an ancillary organ of the immune system, and that cellular traffic into the CNS during EAE is related to the fluctuating expression of several distinct adhesion-related molecules, frequently co-expressed on the same vessel. The findings may have relevance to the sequence of events in the developing CNS lesion of multiple sclerosis. 相似文献
994.
CS Liverman JW Brown R Sandhir RM Klein K McCarson & NEJ Berman 《Cephalalgia : an international journal of headache》2009,29(5):520-531
The mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), is activated in experimental models of chronic pain, and is also activated by oestrogen. We used an established model of inflammatory trigeminal pain, injection of Complete Freund's Adjuvant (CFA) into the masseter muscle, to determine whether ERK activation may play a role in hormone-related trigeminal pain disorders. We measured withdrawal responses to stimulation of the masseter (V3, primary allodynia) and whisker pad (V2, secondary allodynia) using graded monofilaments. Oestrogen treatment in the presence of inflammation increased withdrawal response to stimulation of both masseter and whisker pad compared with inflammation alone, indicating an additive effect of inflammation and oestrogen on both primary and secondary allodynia. We examined ERK activation in trigeminal ganglia from each treatment group using western blot and immunohistochemistry. Both masseter inflammation and oestrogen treatment increased ERK activation, and combined treatment had an additive effect. Both masseter inflammation and oestrogen increased the percentage of pERK immunoreactive neurons in divisions 1 and 2 (V1/2), and combined treatment increased pERK immunoreactivity in V1/2 compared with inflammation alone. We stereotactically administered ERK antagonist U0126, or inactive control U0124, to the trigeminal ganglion of CFA+E2-treated rats. U0126 decreased withdrawal responses to mechanical stimulation of the whisker pad compared with U0124-treated rats. Because the secondary allodynia in V2 after inflammation in V3 was reduced by antagonizing ERK activation in the periphery, these data suggest a peripheral component to secondary allodynia mediated through ERK activation. 相似文献
995.
996.
997.
Impairment of cardiac function and energetics in experimental renal failure. 总被引:5,自引:0,他引:5 下载免费PDF全文
A E Raine A M Seymour A F Roberts G K Radda J G Ledingham 《The Journal of clinical investigation》1993,92(6):2934-2940
Cardiac function and energetics in experimental renal failure in the rat (5/6 nephrectomy) have been investigated by means of an isolated perfused working heart preparation and an isometric Langendorff preparation using 31P nuclear magnetic resonance (31P NMR). 4 wk after nephrectomy cardiac output of isolated hearts perfused with Krebs-Henseleit buffer was significantly lower (P < 0.0001) at all levels of preload and afterload in the renal failure groups than in the pair-fed sham operated control group. In control hearts, cardiac output increased with increases in perfusate calcium from 0.73 to 5.61 mmol/liter whereas uremic hearts failed in high calcium perfusate. Collection of 31P NMR spectra from hearts of renal failure and control animals during 30 min normoxic Langendorff perfusion showed that basal phosphocreatine was reduced by 32% to 4.7 mumol/g wet wt (P < 0.01) and the phosphocreatine to ATP ratio was reduced by 32% (P < 0.01) in uremic hearts. During low flow ischemia, there was a substantial decrease in phosphocreatine in the uremic hearts and an accompanying marked increase in release of inosine into the coronary effluent (14.9 vs 6.1 microM, P < 0.01). We conclude that cardiac function is impaired in experimental renal failure, in association with abnormal cardiac energetics and increased susceptibility to ischemic damage. Disordered myocardial calcium utilization may contribute to these derangements. 相似文献
998.
Clare Collins RN CS PhD FAAN 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1998,27(5):563-568
Mind-body fitness programs use a combination of muscular activity and mindful focus on awareness of the self, breath, and energy to promote health. The ancient discipline of yoga includes physical postures and breathing and meditation techniques. Scientific evidence exists about the physiologic effects of yoga. Mind-body fitness programs may offer therapeutic effects different from those offered by traditional body fitness programs. 相似文献
999.
TOPIC: Children's peer relations are one of the most powerful predictors of mental health PROBLEMS: Peer rejection and neglect are associated with depression, academic problems, school withdrawal, and delinquency. PURPOSE: To provide brief introductions to models of social development and peer rejection, and to introduce a developmental-group psychotherapy model for children experiencing peer neglect or rejection. SOURCES: Theoretical and empirical literature, as well as clinical experience. CONCLUSIONS: Early identification and intervention with children vulnerable to peer rejection are essential. Research addressing affective experiences of peer-rejected children and the relationships between self-perception and treatment outcomes is needed. 相似文献
1000.