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   14670篇
  免费   489篇
  国内免费   533篇
耳鼻咽喉   113篇
儿科学   531篇
妇产科学   288篇
基础医学   947篇
口腔科学   234篇
临床医学   1517篇
内科学   2272篇
皮肤病学   162篇
神经病学   422篇
特种医学   307篇
外国民族医学   16篇
外科学   1297篇
综合类   2111篇
预防医学   2992篇
眼科学   184篇
药学   801篇
  3篇
中国医学   648篇
肿瘤学   847篇
  2024年   10篇
  2023年   195篇
  2022年   388篇
  2021年   457篇
  2020年   345篇
  2019年   32篇
  2018年   135篇
  2017年   100篇
  2016年   995篇
  2015年   897篇
  2014年   676篇
  2013年   565篇
  2012年   966篇
  2011年   1258篇
  2010年   208篇
  2009年   151篇
  2008年   795篇
  2007年   812篇
  2006年   787篇
  2005年   926篇
  2004年   715篇
  2003年   722篇
  2002年   729篇
  2001年   785篇
  2000年   658篇
  1999年   414篇
  1998年   134篇
  1997年   24篇
  1996年   48篇
  1995年   76篇
  1994年   86篇
  1993年   38篇
  1992年   41篇
  1991年   34篇
  1990年   55篇
  1989年   38篇
  1988年   39篇
  1987年   49篇
  1986年   36篇
  1985年   40篇
  1984年   34篇
  1983年   40篇
  1982年   32篇
  1981年   16篇
  1980年   16篇
  1979年   19篇
  1978年   30篇
  1977年   5篇
  1959年   7篇
  1958年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Background: Reports of major and minor sequelae following lidocaine spinal anesthesia have generated interest in an alternative short-acting intrathecal agent. Of the available anesthetics suitable for short-duration spinal anesthesia, prilocaine is perhaps the most promising agent. However, data comparing the neurotoxicity of these agents are lacking. Accordingly, the present experiments investigate whether prilocaine and lidocaine differ with respect to sensory impairment and histologic damage when administered intrathecally in the rat.

Methods: Ninety rats were divided into three groups to receive an intrathecal infusion of 2.5% prilocaine in saline, 2.5% lidocaine in saline, or normal saline. The animals were assessed for persistent sensory impairment 4 days after anesthetic administration using the tail-flick test. Three days later, the animals were killed, and specimens of the spinal cord and nerve roots were obtained for histopathologic examination.

Results: Prilocaine and lidocaine produced equivalent elevations in tail-flick latency that differed significantly from saline. Histologic injury scores with prilocaine were greater than with lidocaine, but this difference did not reach statistical significance.  相似文献   

12.
广西医学院儿少卫生教研室受区卫生厅委托于1985年9月开始举办为期半年的学校卫生医师培训班。来自基层防疫站和学校的31名学  相似文献   
13.
14.
张亦农 《上海医药》2005,26(8):353-353
Biocon公司是印度重要的生物技术公司之一,最近,该公司与Karolinska学院(瑞典最主要的医科大学)签署了一份协议,根据这项协议,双方将在研究、教育领域开展合作。此协议内容包括合作开发产品和共同研究规划。印度生物技术企业欲与瑞典开展合作@张亦农  相似文献   
15.
Background: Despite decades of use, controversy remains regarding the extent and time course of cephalad spread of opioids in cerebrospinal fluid (CSF) after intrathecal injection. The purpose of this study was to examine differences between two often used opioids, morphine and fentanyl, in distribution in the CSF after intrathecal injection.

Methods: Eight healthy volunteers received intrathecal injection of morphine (50 [mu]g) plus fentanyl (50 [mu]g) at a lower lumbar interspace. CSF was sampled through a needle in an upper lumbar interspace for 60-120 min. At the end of this time, a sample was taken from the lower lumbar needle, and both needles were withdrawn. CSF volume was determined by magnetic resonance imaging. Pharmacokinetic modeling was performed with NONMEM.

Results: Morphine and fentanyl peaked in CSF at the cephalad needle at similar times (41 +/- 13 min for fentanyl, 57 +/- 12 min for morphine). The ratio of morphine to fentanyl in CSF at the cephalad needle increased with time, surpassing 2:1 by 36 min and 4:1 by 103 min. CSF concentrations did not correlate with weight, height, or lumbosacral CSF volume. The concentrations of morphine and fentanyl at both sampling sites were well described by a simple pharmacokinetic model. The individual model parameters did not correlate with the distance between the needles, CSF volume, patient height, or patient weight.  相似文献   

16.
Background: The study hypothesizes that nitrous oxide (N2O) releases opioid peptide in the brain stem, which results in inhibition of [gamma]-aminobutyric acid-mediated (GABAergic) neurons that tonically inhibit the descending noradrenergic inhibitory neurons (DNIN), resulting in activation of DNIN. In the spinal cord, activation of DNIN leads to the release of norepinephrine, which inhibits nociceptive processing through direct activation of [alpha]2 adrenoceptor and indirect activation of GABAergic neurons through [alpha]1 adrenoceptor. Arising from this hypothesis, it follows that GABAergic neurons will modulate the antinociceptive effect of N2O in diametrically opposite directions at supraspinal and spinal levels. The authors have tested this tenet and further examined the effect of midazolam, a GABA-mimetic agent, on N2O-induced antinociceptive effect.

Methods: Adult male Fischer rats were administered muscimol (GABAA receptor agonist) intracerebroventricularly (icv), gabazine (GABAA receptor antagonist) intrathecally (intrathecal), or midazolam intraperitoneally (intraperitoneal). Fifteen minutes later, they were exposed to air or 75% N2O and were subjected to the plantar test after 30 min of gas exposure. In some animals administered with midazolam, gas exposure was continued for 90 min, and the brain and spinal cord were examined immunohistochemically.

Results: The N2O-induced antinociceptive effect, which was attenuated by icv muscimol, intrathecal gabazine, and intraperitoneal midazolam. Midazolam inhibited N2O-induced c-Fos expression (a marker of neuronal activation) in the pontine A7 and spinal cord.  相似文献   

17.
辛静 《上海医药》2005,26(8):375-375
印度生物技术主导企业协会(Biotechnology-LedEnterprisesofIndia)计划在美国设立分会,目的是为了在美国发展生物技术工业。美国当地商界有影响的权威人士Sartorious将担任该分会的名誉会长。印度生物技术界试图开拓美国市场@辛静  相似文献   
18.
免疫抑制剂致药物性肾损害   总被引:3,自引:0,他引:3  
《日本医学介绍》2006,27(8):351-355
免疫抑制剂与类固醇激素一起用于器官移植、自身免疫疾病等疾病的治疗。目前作为免疫抑制剂应用的药物有硫唑嘌呤、环磷酰胺、环孢菌素(CyA)和他克莫司,还有日本开发、广泛应用的咪唑立宾(mizoribine,MZB)。近来,免疫抑制剂不仅用于器官移植,也成为肾脏领域肾病综合征以及自身免疫疾病的治疗中不可或缺的一部分。其中钙调神经磷酸酶抑制剂(calcineulin inhibitor,CNI)类免疫抑制剂的共同副作用为肾损害,特别是长期应用导致的慢性肾毒性已成为严重问题。  相似文献   
19.
颈部烧伤后疤痕挛缩、颌颈粘连的治疗方法较多,各有利弊。自1990年12月以来,我们使用双叶瓣治疗颈部疤痕粘连,获得较好效果,现报导如下。皮瓣设计和手术方法一、皮瓣设计,以肩颈部为基部,设计一双叶瓣(即a瓣,b瓣)。a瓣通常与疤痕紧邻,在锁骨中1/3或其附近。a瓣的大小  相似文献   
20.
With the method of rapid gel sequencing, the complete nueleotide sequence of Fasciolopsis buski 5S rRNA has been determined: AAC GGG AUG AAG CUA GAC AUG UGG CGG CCU AGU UGG AGG UCG GAA CUC GGA AGU UAA GGA AUG UUG GGC CUG GUU AGU ACU GGU AUG GGU GAC CUU GGG AAU ACC GGG UGU UGC GUC CA_(OH) This have been compared with 553 species of other organisms 5S rRNA sequences previously published and fitted to a secondary structural model.  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