全文获取类型
收费全文 | 8688篇 |
免费 | 655篇 |
国内免费 | 189篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 53篇 |
妇产科学 | 181篇 |
基础医学 | 276篇 |
口腔科学 | 71篇 |
临床医学 | 1481篇 |
内科学 | 157篇 |
皮肤病学 | 17篇 |
神经病学 | 438篇 |
特种医学 | 161篇 |
外国民族医学 | 2篇 |
外科学 | 2035篇 |
综合类 | 2227篇 |
现状与发展 | 1篇 |
预防医学 | 309篇 |
眼科学 | 10篇 |
药学 | 1456篇 |
17篇 | |
中国医学 | 471篇 |
肿瘤学 | 140篇 |
出版年
2024年 | 21篇 |
2023年 | 135篇 |
2022年 | 190篇 |
2021年 | 302篇 |
2020年 | 291篇 |
2019年 | 271篇 |
2018年 | 242篇 |
2017年 | 284篇 |
2016年 | 265篇 |
2015年 | 266篇 |
2014年 | 600篇 |
2013年 | 595篇 |
2012年 | 565篇 |
2011年 | 578篇 |
2010年 | 465篇 |
2009年 | 390篇 |
2008年 | 467篇 |
2007年 | 447篇 |
2006年 | 403篇 |
2005年 | 384篇 |
2004年 | 285篇 |
2003年 | 262篇 |
2002年 | 228篇 |
2001年 | 192篇 |
2000年 | 146篇 |
1999年 | 101篇 |
1998年 | 108篇 |
1997年 | 89篇 |
1996年 | 86篇 |
1995年 | 89篇 |
1994年 | 65篇 |
1993年 | 59篇 |
1992年 | 53篇 |
1991年 | 42篇 |
1990年 | 42篇 |
1989年 | 42篇 |
1988年 | 29篇 |
1987年 | 37篇 |
1986年 | 54篇 |
1985年 | 73篇 |
1984年 | 68篇 |
1983年 | 53篇 |
1982年 | 55篇 |
1981年 | 40篇 |
1980年 | 29篇 |
1979年 | 13篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1975年 | 5篇 |
排序方式: 共有9532条查询结果,搜索用时 15 毫秒
71.
72.
In order to detect possible interaction between GABA and opiates, the effects of GABA-ergic drugs on analgesia induced by morphine were studied. The vocalization response to electrical stimulation of the tail in rats was used as an index of the action of morphine. Thiosemicarbazide, an inhibitor of glutamate decarboxylase, and bicuculline, which blocks GABA-ergic receptors, drugs which, it is suggested, can be considered as a group of GABA-negative compounds, weaken and shorten the effect of morphine. Depakine, an inhibitor of -ketoglutarate-GABA-transaminase, like GABA itself, given in large doses (GABA-positive effects) strengthens morphine analgesia and prolongs its effect. The possible causes of these relations between GABA and opiates are discussed.Laboratory of Pharmacology of the Nervous System, Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 35–37, July, 1979. 相似文献
73.
目的观察不同镇痛方式在开胸手术后的镇痛效果及其对肺功能的影响。方法39例ASAⅠ~Ⅱ级,在硬膜外复合全身麻醉下行侧开胸手术的病人,术后随机接受罗哌卡因(罗哌组,n=10)、甲磺酸罗哌卡因(甲罗组,n=10)和布比卡因(布比组,n=10)硬膜外镇痛(patient controlled epidural analgesia,PCEA)及吗啡(吗啡组,n=9)静脉镇痛(patient controlled intravenous analgesia,PCIA)。结果术后1、2、5d静息时的疼痛评分罗哌组和甲罗组均明显低于布比组,但与吗啡组相比无明显差异;术后1d静息时疼痛评分吗啡组也明显低于布比组,但术后2、5d两组间无明显差异。术后1、2、5d咳嗽时疼痛评分罗哌组均明显低于布比组和吗啡组;各时间咳嗽时疼痛评分布比组和吗啡组之间无明显差异。术后1、2dPaCO2罗哌组均明显低于布比组,术后1dPaCO2罗哌组也明显低于布比组;术后1、2dPaCO2罗哌组均明显高于吗啡组,但与布比组之间无明显差异。术后1、2、5d用力肺活量和呼吸峰流速四组间无明显差异。结论罗哌卡因和甲磺酸罗哌卡因加舒芬太尼可安全用于开胸手术后硬膜外镇痛,其镇痛效果优于布比卡因加芬太尼硬膜外镇痛和吗啡静脉镇痛,并使术后病人维持更好的呼吸功能,且不增加副作用的发生率。 相似文献
74.
75.
76.
77.
78.
(1) The spread of epidural analgesia following injection of 15ml of 2% mepivacaine was 17.3 ± 0.6, 14.3 ± 0.4, and 13.3 ± 0.7 spinal segments in cervical, thoracic, and lumbar epidural analgesia, respectively. The patients age showed significant correlation with the spread of epidural analgesia in cervical (r = 0.5776, p < 0.001), thoracic (r = 0.3758, p < 0.01), and lumbar area (r = 0.8195, p < 0.001). The spread of cervical epidural analgesia was more caudad than cephalad (p < 0.05), but in lumbar epidural analgesia it was more cephalad than caudad (p < 0.05). There was no difference between the cephalad and caudad spread in thoracic epidural analgesia.(2) The epidural pressure immediately after injection of 15ml of 2% mepivacaine into the lumbar epidural space at a constant pressure (80mmHg) correlated to the patients age (r = –0.5714, p < 0.001) and the spread of analgesia (r = –0.3904, p < 0.05). The lower epidural pressure associated with higher age, the wider spread of analgesia. There was no significant correlation between the residual pressure at 60 seconds and the age or the spread of analgesia.(Hirabayashi Y et al.: Spread of epidural analgesia following a constant pressure injection: an investigation of relationships between locus of injection, epidural pressure and spread of analgesia. J Anesth 1: 44–50, 1987) 相似文献
79.
The relationships between the epidural pressures following the injection of local anesthetic solution and the spread of epidural analgesia were investigated. In 46 patients, 15ml of 2% mepivacaine was injected into the lumbar epidural space at a constant rate (1ml/sec) using an electropowered syringe pump. Injection pressures and residual pressures were recorded and the spread of analgesia to pinprick was assessed. The changes of the epidural pressures during and following the injection of a volume of local anesthetic solution in old subjects were significantly smaller than those in young subjects (P < 0.05). The spread of analgesia closely correlated with the epidural pressures during and following the injection of local anesthetic solution. The most close correlation was found between the epidural pressure immediately after the completion of injection and the spread of analgesia (r = –0.5659, P < 0.001). In conclusion, the lower the terminal injection pressure and the residual pressures associated with higher age, the wider the spread of epidural analgesia.(Hirabayashi Y, Matsuda I, Inoue S et al.: Epidural pressure and its relation to spread of epidural analgesia. J Anesth 1: 168–172, 1987) 相似文献
80.
目的 :探讨异氟醚用于阴道分娩镇痛对新生儿神经行为的影响。方法 :75例产妇随机分为异氟醚组、笑气组和对照组 ,采用新生儿神经适应能力评分 (NACS)对新生儿出生后 15min ,2h及 2 4h进行监测。结果 :3组新生儿的神经行为状态差异无显著性 (P >0 0 5 )。 15min ,2h及 2 4h的评分相比 ,3组新生儿均为 2h的评分最低。 2 4h评分时 ,3组分别有 92 %、89%和 90 %的新生儿评为高分。结论 :吸入异氟醚分娩镇痛对新生儿 15min、2h及 2 4h的神经行为状态无不良影响。 相似文献