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   1022篇
  免费   60篇
  国内免费   27篇
耳鼻咽喉   7篇
儿科学   5篇
妇产科学   39篇
基础医学   160篇
口腔科学   14篇
临床医学   98篇
内科学   89篇
皮肤病学   7篇
神经病学   54篇
特种医学   37篇
外科学   58篇
综合类   138篇
预防医学   83篇
眼科学   75篇
药学   108篇
中国医学   116篇
肿瘤学   21篇
  2023年   10篇
  2022年   37篇
  2021年   54篇
  2020年   33篇
  2019年   32篇
  2018年   23篇
  2017年   23篇
  2016年   29篇
  2015年   35篇
  2014年   87篇
  2013年   58篇
  2012年   83篇
  2011年   78篇
  2010年   64篇
  2009年   55篇
  2008年   56篇
  2007年   54篇
  2006年   42篇
  2005年   24篇
  2004年   33篇
  2003年   24篇
  2002年   15篇
  2001年   15篇
  2000年   14篇
  1999年   10篇
  1998年   9篇
  1997年   7篇
  1996年   8篇
  1995年   8篇
  1994年   8篇
  1993年   9篇
  1992年   5篇
  1991年   4篇
  1990年   3篇
  1989年   7篇
  1988年   4篇
  1987年   5篇
  1986年   7篇
  1985年   10篇
  1984年   6篇
  1983年   2篇
  1982年   5篇
  1981年   5篇
  1980年   2篇
  1979年   4篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
排序方式: 共有1109条查询结果,搜索用时 81 毫秒
1.
2.
L-acetylcarnitine is a compound with cholinergic properties and putative action on the visual system and the glucose metabolism. Ten healthy, emmertropic volunteers (age range: 21 to 28 years) were studied. Each subject was administered 5, 10, and 30 mg/kg acute intravenous doses of L-acetylcarnitine and matching placebo. Retinal oscillatory potentials to full-field flash stimulation were recorded before and 30, 60, and 120 min after administration. A systematic reduction of the implicit time of the P2 and N2 oscillatory potential components was observed after administration of the 10 and 30 mg/kg doses: significant changes were not evident at the 5 mg dose or after placebo. The latency reduction was significantly correlated with the postdrug increment of the L-acetylcarnitine plasma concentration. No other systematic modification in latency of amplitude was observed.The results were presented in part at the XXV I.S.C.E.V. Symposium, Sarasota (Florida), April 26–30, 1987.  相似文献   
3.
本文报告大鼠分别在6时、12时、18时、24时接受汤岗子矿泉38~39℃浸浴15分钟后,立即断头取血测定血液皮质醇及甲状腺素(T_4)。在6时、24时的矿泉浸浴组大鼠血浆皮质醇比对照组明显升高。在12时、18时矿泉浸浴组大鼠血清T_4比对照组明显升高。说明肾上腺皮质及甲状腺功能对全身矿泉浸浴热刺激的反应也遵循日周期节律。为矿泉治疗的时间生物学理论提供依据。  相似文献   
4.
Electroretinograms and retinal oscillatory potentials to full-field flash stimulation were recorded by dermal electrodes in a population of subjects (1 to 84 yrs) balanced for age and sex (119 females, 133 males), without evidence or history of ocular and/or relevant systemic diseases. The electroretinogram latencies and b-wave amplitude increased, while the a-wave amplitude decreased linearly with age. The oscillatory potential amplitude initially increased, to decrease approximately at the age of 50, with an inverted U-shaped distribution.Presented in part at the XXV ISCEV Symposium, Sarasota (Florida), April 26–30, 1987.  相似文献   
5.
Mice immunized against anti-substance P (anti-SP) monoclonal antibodies produced anti-SP anti-idiotypic antibodies (SPAb2). In a previous report. SPAb2 antibodies were found to have in vitro biological activity i.e. to behave either as agonists or as antagonists for substance P (SP) depending on the biological test. In this study, the involvement of SPAb2 in vivo biological activity has been tested. Because of the possible implication of SP in the generation and transmission of nociceptive information, we have tested the responsiveness of SPAb2 responding mice in behavioral nociceptive tests. SPAb2 mice showed very small behavioral variations in the hot plate test as compared with a control group of mice immunized against an unrelated monoclonal antibody. In the formalin test, however, SPAb2 mice displayed a significant increase in paw licking time, which was significantly correleted with SPAb2 serum concentration. These results are discussed in terms of the use of SPAb2 as pharmacological tools for studying the biological properties of SP receptors and more generally of auto anti-idiotypic antibodies in modulating behavior responses.  相似文献   
6.
目的 探讨亚低温治疗高温高湿环境下重型颅脑损伤的护理方法。方法 高温高湿环境下的重型颅脑损伤患者60例,随机分为亚低温治疗组和对照组。规范护理程序,严密观察病人生命体征变化,采取积极护理措施,减少并发症。结果 亚低温治疗24h后颅内压逐渐下降,脑组织PO2逐渐上升,伤后3个月亚低温治疗组的良好率明显高于对照组(P〈0.05),而死亡率明显低于对照组(P〈0.01)。结论 精心护理有助于改善亚低温治疗的高温高湿环境下重型颅脑损伤病人的预后。  相似文献   
7.
目的 探讨高温高湿环境下守岛官兵训练前后脑血流和脑电生理的变化,为临床防治热致疾病提供依据.方法 从守岛官兵中随机抽取在常温常湿环境下温度(27.40±1.37)℃,湿度(50.25±6.76)%]新兵100名为常温新兵组,高温高湿环境下(温度≥35℃,湿度≥80%)新兵100名为高温新兵组;高温高湿环境下服役2~3 年的官兵100名为高温老兵组.受试者负重15 kg,分次在3000 m/15 min,5000 m/30 min和10 000 m/45 min内完成跑步训练.10 000 m训练后,根据受试者脑血流高低又分为脑血流增高组(24名)、脑血流降低组(46名)和脑血流正常组(230名).训练前后行经颅多普勒血流诊断仪和脑电图仪检测.结果 (1)3000 m训练后3组受试官兵脑平均血流速度(Vm)较训练前均显著增高(P<0.01),但5000 m和10 000 m训练后,常温新兵组降低6%和16%,高温老兵组降低5%和15%,高温新兵组降低14%和31%,比常温新兵组和高温老兵组低(P<0.01);(2)10 000 m训练前后3组脑电图均在正常范围,3组比较差异无统计学意义(P>0.05);(3)10 000 m训练后脑血流增高组和降低组脑电图比正常血流组活跃(P<0.01).结论 高温高湿环境下10 000 m训练对官兵的脑血流有较大的影响,但对脑电生理无影响,老兵在此环境下则表现出较好的热耐受力和适应性.  相似文献   
8.
Objectives: To assess the efficacy and tolerability of a new matrix patch delivering 0.05 mg estradiol per day (Estraderm MX 50) in postmenopausal women with moderate to severe postmenopausal symptoms. Methods: A multicenter, double-blin, randomized, between-patient, placebo controlled trial in 109 postmenopausal women was carried out. Patches were applied twice weekly for 12 weeks. Patients were assessed at 4, 8 and 12 weeks of treatment. The primary efficacy variable was change from baseline in mean number of moderate to severe hot flushes (including night sweats) per 24 h during the last 2 weeks of treatment. Other variables included Kupperman Index, local and systemic tolerability. Plasma concentrations of estradiol (E2), estrone (E1) and estrone sulfate (E1S) were determined before and after treatment. Results: Estraderm MX was significantly superior to placebo (P < 0.001) in reducing mean number of moderate to severe hot flushes (including night sweats) per 24 h after 4, 8 and 12 weeks of treatment. The estimate of treatment group differences after 12 weeks was 4.2 hot flushes (95% confidence interval: 2.6–5.5). Estraderm MX also significantly reduced Kupperman Index at all time points compared to placebo (P < 0.001). Estraderm MX induced increases in mean E2, E1 and E1S plasma levels as expected (E2: baseline 2.7 pg/ml, 12 weeks 38.9 pg/ml; E1: baseline 18.8 pg/ml, 12 weeks 41.6 pg/ml; E1S: baseline 235.6 pg/ml, 12 weeks 765.1 pg/ml). Overall rates of adverse experiences were similar for Estraderm MX and placebo. The number of patients reporting skin irritation was low and similar in both groups. Conclusions: Estraderm MX 50, a new matrix patch, offers an effective and well tolerated dosage form for transdermal delivery of 0.05 mg E2 per day.  相似文献   
9.
刘迎九 《医学信息》2004,17(10):626-628
本文通过用Flash 5.0制作《医学电子学》中PN结的形成过程的介绍,在熟悉Flash 5.0制作方法的同时.完成相应的多媒体教学。  相似文献   
10.
Laboratory and Ambulatory Monitoring of Menopausal Hot Flashes   总被引:2,自引:0,他引:2  
A large increase in skin conductance activity recorded from the sternum was found during menopausal hot flashes and corresponded well with patient self-reports. The magnitude and time course of this skin conductance change was similar during spontaneous hot flashes recorded in the laboratory, during heat-induced hot flashes, and during those recorded by ambulatory monitoring techniques. This pattern of sternal skin conductance change did not occur in premenopausal women during body heating or ambulatory monitoring. These methods should be useful in research on the etiology and treatment of menopausal hot flashes.  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