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   12614篇
  免费   777篇
  国内免费   267篇
耳鼻咽喉   35篇
儿科学   101篇
妇产科学   245篇
基础医学   359篇
口腔科学   75篇
临床医学   1948篇
内科学   248篇
皮肤病学   21篇
神经病学   632篇
特种医学   264篇
外国民族医学   2篇
外科学   3670篇
综合类   3092篇
现状与发展   2篇
预防医学   425篇
眼科学   26篇
药学   1773篇
  21篇
中国医学   518篇
肿瘤学   201篇
  2024年   21篇
  2023年   156篇
  2022年   245篇
  2021年   382篇
  2020年   365篇
  2019年   336篇
  2018年   300篇
  2017年   363篇
  2016年   356篇
  2015年   347篇
  2014年   793篇
  2013年   791篇
  2012年   764篇
  2011年   793篇
  2010年   635篇
  2009年   557篇
  2008年   650篇
  2007年   658篇
  2006年   583篇
  2005年   563篇
  2004年   427篇
  2003年   410篇
  2002年   365篇
  2001年   316篇
  2000年   245篇
  1999年   192篇
  1998年   182篇
  1997年   150篇
  1996年   157篇
  1995年   145篇
  1994年   132篇
  1993年   131篇
  1992年   101篇
  1991年   94篇
  1990年   101篇
  1989年   92篇
  1988年   82篇
  1987年   76篇
  1986年   80篇
  1985年   105篇
  1984年   89篇
  1983年   73篇
  1982年   78篇
  1981年   57篇
  1980年   50篇
  1979年   24篇
  1978年   15篇
  1977年   10篇
  1976年   8篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
81.
目的 观察可乐定透皮贴剂联合芬太尼静脉自控镇痛(PCIA)用于原发性高血压(EH)病人术后镇痛的效果.方法 择期全麻下行腹腔镜胆囊切除术病人60例,均合并EH,依据术后镇痛方法的不同,随机均分为三组,肌注哌替啶组(P组)、芬太尼PCIA组(F组)和可乐定透皮贴剂联合芬太尼PCIA组(CF组).使用芬太尼1.0mg稀释至100ml,PCIA均采用负荷量-持续背景量-PCA量模式,背景剂量芬太尼20 μg/h,PCA追加剂量5 μg,锁定时间15 min.记录病人术后镇痛4、8、24、48 h VAS及Ramsay镇静评分,并记录不良反应和处理措施.监测入院时、术后24、48 h血浆内皮素(ET)及降钙素基因相关肽(CGRP)浓度、血糖(Glu),同时记录MAP、HR.结果 镇痛期间F、CF组VAS低于P组(P<0.01),CF组低于F组(P<0.05).Ramsay镇静评分F组高于P组(P<0.01),CF组高于F组(P<0.05),三组均无过度镇静.CF组MAP、HR术后较入院时明显降低(P<0.01),血浆ET、血浆CGRP浓度与入院时比较差异无统计学意义.术后ET、Glu浓度和MAP、HR F组低于P组,CGRP浓度高于P组(P<0.05).术后ET、Glu浓度和MAP、HR P组>F组>CF组;术后CGRP浓度:CF组>F组>P组(P<0.05).不良反应发生率三组差异无统计学意义.结论 对高血压病人,可乐定透皮贴剂增强芬太尼PCIA镇痛作用,使血流动力学更稳定.  相似文献   
82.
目的研究布托啡诺用于老年患者术后静脉镇痛的疗效及不良反应。方法60例择期行上腹部手术的老年患者,随机均分为布托啡诺组(B组)、芬太尼组(F组)及芬太尼联合曲马多组(FT组),分别接受持续静脉镇痛。记录并比较术后48h内疼痛视觉模拟评分(VAS)、Ramsay镇静评分及不良反应。结果三组术后镇痛效果VAS组内比较差异无统计学意义。但术后6hF组和B组的VAS明显低于FT组(P<0.05);术后12h,B组的VAS仍低于FT组(P<0.05)。B组术后0.5、6、12h Ramsay镇静评分明显高于F组(P<0.05)。B组恶心呕吐发生率明显低于FT组(P<0.05)。结论布托啡诺可用于老年患者术后静脉镇痛。  相似文献   
83.
HP 818 (1-benzoyl-6-fluoro-3-(1-methyl-4-piperidinyl)-1H-indazole) exhibits the profile of a potent nonnarcotic analgesic with neuroleptic properties. HP 818 blocks the effects of chemical (phenylquinone), pressure (tail clip), and radiant heat (tail flick) painful stimuli in mice (ED50 values of 0.3, 1.2, and 4.1 mg/kg s.c., respectively). This compound displays antinociceptive activity by the subcutaneous, oral, and intravenous routes of administration. It is also effective in the shock titration assay in squirrel monkeys and in a model of surgically induced pain. The rank order of potency of HP 818 and several other standard compounds in these tests for analgesia was Innovar > fentanyl > HP 818 > codeine > droperidol. In addition to its antinociceptive effects, HP 818 possesses neuroleptic properties. It is active in the climbing mouse, pole climb avoidance, and intracranial self-stimulation assays (ED50 values of 1.8, 1.7, and 2.5 mg/kg i.p., respectively). Moreover, HP 818 inhibits amphetamine- and apomorphine-induced stereotypy, indicative of D2-dopaminergic blocking properties. HP 818, unlike typical neuroleptic agents, does not induce supersensitivity to the effects of apomorphine when administered chronically in mice. In contrast to the clinical standard neuroleptanalgesic Innovar, HP 818 (1.0–3.0 mg/kg i.v.) produces no significant cardiovascular or respiratory changes in the anesthetized dog. Thus, HP 818 is potentially an effective presurgical medication due to its nonnarcotic analgesic activity and sedative neuroleptic effects, along with its lack of limiting cardiorespiratory side effects.  相似文献   
84.
N. M. Gajraj  MB  BS  FRCA    S. K. Sharma  MB  BS  FRCA    A. J. Souter  MB  BS  FRCA    Y. Pole  MB  BS  FRCA    J. E. Sidawi  MD   《Anaesthesia》1995,50(8):740-741
  相似文献   
85.
电针改善硬膜外吗啡用于术后镇痛所引起的免疫抑制   总被引:1,自引:1,他引:0  
为观察硬膜外吗啡和电针对术后患者免疫功能的影响,检测自然杀伤细胞(NKcell)活性和PHA诱导白细胞介素2(IL-2)水平在单纯胆囊切除术患者术前和术后第1、3、7天的动态变化情况。结果吗啡组NK活性在术后第1、3、7天抑制,手术组仅在术后第1、3天出现抑制,而抑制率低于同天的吗啡组,电针可拮抗吗啡引起的NK活性抑制加深状况。在术后第1天,手术组和吗啡组IL-2水平均下降,吗啡+电针组无明显变化,术后第7天吗啡+电针组IL-2升高接近正常人水平。表明电针能改善硬膜外吗啡引起的免疫抑制,促进术后机体的恢复。硬膜外吗啡结合电针是值得推荐的术后镇痛方法。  相似文献   
86.
通过抑制子宫平滑肌、镇痛及抗炎等试验评价月舒贴药液对原发性痛经的主要功效。结果表明:月舒贴药液有抑制正常大鼠子宫平滑肌收缩频率、幅度的趋势,明显对抗缩宫素所致子宫平滑肌收缩作用,显著抑制冰醋酸对小鼠的致痛作用,明显抑制大鼠足趾部肿胀作用。上述结果提示月舒贴可有效的缓解痛经的症状和体征。  相似文献   
87.
The authors report a retrospective study of 390 cancer pain patients tested with oral morphine during a four-month period. Initial pain scores were reduced to one half after one week of treatment and then maintained throughout the study period. Mean daily dosages of morphine were lower in those patients 65 years and older. No significant changes in performance in relation to therapy were noted except for an increase in hours of sleep. An accurate titration of dosage and continued control of side effects are the main requirements of this method of administration. The presence of side effects and the cause of interruption of treatment are reported.  相似文献   
88.
The effects of a prostaglandin synthesis inhibitor (diclofenac, Voltaren) and an opiate (oxycodone, Oxanest) on postoperative pain were compared. Included in the study were 85 candidates for various operations. Patients requesting an analgesic were given either 75 mg of diclofenac or 10 mg of oxycodone as an intramuscular injection. The onset of analgesic effect occurred within 13 +/- 4 min with oxycodone and within 16 +/- 8 min with diclofenac. The analgesic effect of diclofenac was slightly weaker than that of oxycodone (on a pain scale of 1-4, 1.6/2.1 after 0.5 h and 1.5/1.8 after 1 h). The patients again asked for an analgesic after an average of 4.6 h in the oxycodone group and after an average of 6.1 h in the diclofenac group. The average number of injections required until the first postoperative morning was 2.5 in the oxycodone group and 1.8 in the diclofenac group. Side-effects: 21 patients in the oxycodone group reported a total of 39 side-effects and eight patients in the diclofenac group a total of 10 side-effects. Diclofenac is an alternative to opiates in the management of postoperative pain. It is especially useful in patients in whom opiates cause side-effects.  相似文献   
89.
Summary In order to assess whether the indications for conservative treatment of supratentorial epidural haematomas are applicable also to posterior fossa epidural haematomas (PFEDH), the author reviewed the records of 25 patients. With a PFEDH volume of no more than 10 ml, a thickness of no more than 15 mm, a midline shift of no more than 5 mm, and in the absence of a significant intracranial haematoma elsewhere on computed tomography (CT) scans, the patients undergoing conservative treatment achieved the same excellent outcome as those undergoing early surgery. These CT criteria for conservative treatment of PFEDHs are similar to those of supratentorial epidural haematomas except the volume factor, namely, 10 ml in the former against 30 ml in the latter. That means a PFEDH of 10 ml or larger in the small posterior fossa may produce the same degree of midline shift and compression, and be as dangerous as an epidural haematoma of 30 ml or larger in the more capacious supratentorial compartment. But also for epidural haematomas of the posterior fossa, which initially are smaller than 10 ml, the general rule remains valid that they should be under close clinical supervision  相似文献   
90.
Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.  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