全文获取类型
收费全文 | 30710篇 |
免费 | 1759篇 |
国内免费 | 108篇 |
专业分类
耳鼻咽喉 | 346篇 |
儿科学 | 627篇 |
妇产科学 | 846篇 |
基础医学 | 3823篇 |
口腔科学 | 1550篇 |
临床医学 | 2378篇 |
内科学 | 7679篇 |
皮肤病学 | 714篇 |
神经病学 | 2588篇 |
特种医学 | 644篇 |
外国民族医学 | 1篇 |
外科学 | 4018篇 |
综合类 | 200篇 |
一般理论 | 8篇 |
预防医学 | 2681篇 |
眼科学 | 481篇 |
药学 | 2237篇 |
中国医学 | 183篇 |
肿瘤学 | 1573篇 |
出版年
2023年 | 252篇 |
2022年 | 647篇 |
2021年 | 1123篇 |
2020年 | 647篇 |
2019年 | 921篇 |
2018年 | 1179篇 |
2017年 | 764篇 |
2016年 | 811篇 |
2015年 | 936篇 |
2014年 | 1282篇 |
2013年 | 1622篇 |
2012年 | 2337篇 |
2011年 | 2417篇 |
2010年 | 1283篇 |
2009年 | 1140篇 |
2008年 | 1871篇 |
2007年 | 1765篇 |
2006年 | 1650篇 |
2005年 | 1557篇 |
2004年 | 1363篇 |
2003年 | 1158篇 |
2002年 | 1094篇 |
2001年 | 483篇 |
2000年 | 454篇 |
1999年 | 386篇 |
1998年 | 208篇 |
1997年 | 163篇 |
1996年 | 157篇 |
1995年 | 136篇 |
1994年 | 113篇 |
1993年 | 97篇 |
1992年 | 252篇 |
1991年 | 213篇 |
1990年 | 209篇 |
1989年 | 168篇 |
1988年 | 156篇 |
1987年 | 112篇 |
1986年 | 147篇 |
1985年 | 123篇 |
1984年 | 102篇 |
1983年 | 81篇 |
1982年 | 80篇 |
1981年 | 64篇 |
1980年 | 67篇 |
1979年 | 102篇 |
1978年 | 59篇 |
1977年 | 56篇 |
1975年 | 57篇 |
1974年 | 59篇 |
1973年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Recent longitudinal studies using personality questionnaires and ratings have shown remarkable stability across the adult years. In an investigation of age changes and differences in personality as measured by the Holtzman Inkblot Technique (HIT), ninety-three men and women aged twenty-five to ninety were administered Form A of the HIT; forty-four of these were retested one to three years later. Stability coefficients ranged from .07 for Form Appropriateness to .73 for Form Definiteness, with most variables showing significant but moderate stability. Repeated measures analyses of variance showed increases in six variables and decreases in two others, but only one of these changes was paralleled by cross-sectional age differences. Correlations with self-report measures of the broad personality domains of neuroticism, extraversion, and openness to experience failed to show hypothesized relations, and the associations seen were attributable to chance. It was concluded that the HIT measures perceptual-cognitive variables that are moderately stable in adulthood. 相似文献
22.
Muscarinic receptor-stimulated phosphoinositide metabolism has been recently suggested as a possible target for the neurotoxic effects of ethanol during brain development. Since two other alcohols, tertiary butanol and n-propanol, have been shown to cause microencephaly in the rat when administered during the brain growth spurt, in the present study we investigated the in vitro effects of five short chain aliphatic alcohols on muscarinic receptor-stimulated phosphoinositide metabolism in cerebral cortical slices from 7 day-old rats. In neonatal animals all alcohols tested inhibited carbachol (1 mM)-stimulated [3H]inositol phosphates accumulation in a dose- and time-dependent manner. The order of potency was t-butanol greater than n-propanol greater than or equal to iso-propanol greater than ethanol greater than methanol. After 90 min of incubation, ethanol, n-propanol and t-butanol caused a significant inhibition of muscarinic receptor-stimulated inositol metabolism at doses as low as 15 - 50 mM, comparable to the blood concentrations reached after in vivo administration of doses able to induce developmental neurotoxicity. The inhibitory effect of ethanol was additive to that of iso-propanol or t-butanol. Differently from these effects in 7 day-old rats, in cortical slices from adult animals methanol and ethanol had no effect on carbachol-stimulated phosphoinositide metabolism, while the two propanol isomers and t-butanol were less effective than in neonatal animals. These results suggest that muscarinic receptor-coupled phosphoinositide metabolism might be a common neurochemical target for the developmental neurotoxicity of short chain aliphatic alcohols. 相似文献
23.
24.
Presenting a clinical case, the authors reveal the possible cholesteatoma complications arising from otospongious surgery. He notice that there are very few literature about similar cases. Underlining the rarity of this complication, the authors will put forward concisely the principal etiological mechanisms occurring in this kind of pathology. Since the reoperation must often be carried out on fragile inner ears, the authors stress on the necessity to respect the elementary rules of prevention in order to avoid the formation of precholesteatoma states. 相似文献
25.
Renato S. Gomez L. O. F. Andrade J. R. Rezende Costa 《Journal canadien d'anesthésie》1997,44(7):732-734
Purpose To present a case of brainstem anaesthesia as a complication of peribulbar anaesthesia.
Clinical features A 75-yr-old woman received peribulbar anaesthesia for cataract surgery. A few seconds after the block was performed, she had
a respiratory arrest, became unconscious, and developed hypertension and tachycardia followed by hypotension and bradycardia.
Ventilatory and haemodynamic support were performed before the patient regained adequate spontaneous breathing and normal
heart rate and blood pressure.
Conclusion Peribulbar anaesthesia generally cames a low risk of serious complications. However, respiratory arrest and brainstem anaesthesia
may occur as complications of peribulbar blocks.
Résumé Objectif Présenter un cas d’anesthésie du tronc cérébral compliquant une anesthésie péribulbaire. éléments cliniques Un bloc péribulbaire était réalisé chez une femine de 75 ans pour l’extraction d’une cataracte. Quelques secondes après l’injection, la patiente cessait de respirer et perdait conscience. Elle devenait hypertendue et tachycarde puts hypotendue et bradycarde. La ventilation et la circulation devaient être supportées jusqu’au retour spontané à la normale. Conclusion En général, l’anesthésie péribulbare comporte un faible risque de complications sérieuses. Un arrêt respiratoire par anesthésie du tronc cérébral est toujours possible.相似文献
26.
27.
28.
29.
Raquel Carreira Ana Duarte Pedro Monteiro Maria Sancha Santos Ana Cristina Rego Catarina R Oliveira Lino M Gon?alves Luís A Providência 《Revista portuguesa de cardiologia》2004,23(11):1447-1455
Ischemia negatively affects mitochondrial function by inducing the mitochondrial permeability transition (MPT). The MPT is triggered by oxidative stress, which occurs in mitochondria during ischemia as a result of diminished antioxidant defenses and increased reactive oxygen species production. It causes mitochondrial dysfunction and can ultimately lead to cell death. Therefore, drugs able to minimize mitochondrial damage induced by ischemia may prove to be clinically effective. We analyzed the effect of carvedilol, a beta-blocker with antioxidant properties, on mitochondrial dysfunction. Carvedilol decreased levels of TBARS (thiobarbituric acid reactive substances), an indicator of oxidative stress, which is consistent with its antioxidant properties. Regarding cell death by apoptosis, although ischemia did increase caspase-8-like activity, there were no changes in caspase-3-like activity, which is activated downstream of caspase-8; this may indicate that the apoptotic cascade is not activated by 60 minutes of ischemia. We conclude that carvedilol protects ischemic mitochondria by preventing oxidative mitochondrial damage, and, by so doing, it may also inhibit the formation of the MPT pore. 相似文献
30.
Andrew H Evans Durval C Costa Sveto Gacinovic Regina Katzenschlager John D O'sullivan Simon Heales Phillip Lee Andrew J Lees 《Movement disorders》2004,19(10):1232-1236
Reports of parkinsonism in phenylketonuria are exceedingly rare. We report on a patient who had received a delayed diagnosis of phenylketonuria as an infant and subsequently developed levodopa-responsive parkinsonism at the age of 33. Single-photon emission computed tomography (SPECT) using (123)I-FP-CIT ([(123))I]-2 beta-carbomethoxy-3beta-(-4-iodophenyl)-N-(3-fluoropropyl)-nortropane) used to measure dopamine transporter levels on two occasions, 7 and 9 years after the onset of neurological symptoms, were normal. Iodine-123-iodo-lisuride SPECT (IBZM) imaging, however, showed reduced caudate over putamen binding. This combination of imaging findings indicates a possible upregulation of postsynaptic D2 receptors in the context of intact presynaptic dopamine nerve terminal density. 相似文献