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   10919篇
  免费   1362篇
  国内免费   654篇
耳鼻咽喉   31篇
儿科学   68篇
妇产科学   29篇
基础医学   824篇
口腔科学   206篇
临床医学   571篇
内科学   1104篇
皮肤病学   78篇
神经病学   433篇
特种医学   175篇
外国民族医学   4篇
外科学   585篇
综合类   2226篇
现状与发展   3篇
预防医学   1195篇
眼科学   161篇
药学   2292篇
  9篇
中国医学   2545篇
肿瘤学   396篇
  2024年   84篇
  2023年   367篇
  2022年   650篇
  2021年   897篇
  2020年   729篇
  2019年   513篇
  2018年   424篇
  2017年   431篇
  2016年   440篇
  2015年   412篇
  2014年   748篇
  2013年   780篇
  2012年   804篇
  2011年   788篇
  2010年   600篇
  2009年   508篇
  2008年   513篇
  2007年   515篇
  2006年   388篇
  2005年   337篇
  2004年   283篇
  2003年   265篇
  2002年   195篇
  2001年   127篇
  2000年   133篇
  1999年   99篇
  1998年   82篇
  1997年   78篇
  1996年   70篇
  1995年   66篇
  1994年   60篇
  1993年   56篇
  1992年   51篇
  1991年   39篇
  1990年   42篇
  1989年   28篇
  1988年   45篇
  1987年   31篇
  1986年   32篇
  1985年   36篇
  1984年   28篇
  1983年   18篇
  1982年   29篇
  1981年   17篇
  1980年   16篇
  1979年   15篇
  1978年   13篇
  1977年   10篇
  1976年   13篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
前后挤压型骶骨Ⅱ区骨折与骶丛神经损伤的关系   总被引:1,自引:0,他引:1  
目的 探讨前后挤压致骶骨Ⅱ区骨折造成骶丛神经损伤的机制。方法 经甲醛短期(1年内)浸泡固定的国人尸体6具,12侧。解剖保护骶丛神经,制成前后挤压型暴力致骶Ⅱ区骨折模型,定量测量不同骨折移位时骶丛神经被拉长的距离。另外,利用X线片观察骶从神经受压情况。结果 随耻骨联合分离逐渐增大,骶丛神经张应变呈直线相关逐渐加大,以S1,S4为最显著,且可造成神经的刺伤,多见于L5和S1,X线未发现骶丛神经受压表现。结论 前后挤压型暴力致骶骨Ⅱ区骨折神经损伤以牵拉伤为丰,以S1,S4为主,且与骨折移位程度成正相关关系。神经的刺伤,多见于骨折移位较大的L5和S1。  相似文献   
32.
Vascular malformation (AVM) in the gastrointestinal tract is an uncommon, but not rare, cause of bleeding and iron deficiency anemia, especially in an aging population. While endoscopic coagulative therapy is the method of choice for controlling bleeding, a substantial number of cases require additional therapy. Adjunctive or even primary phamacotherapy may be indicated in recurrent bleeding. However, there is little evidence-based proof of efficacy for any agent. The bulk of support is derived from anecdotal reports or case series. The present review compares the outcome of AVM after no intervention, coagulative therapy or focus on pharmacological agents. Most of the literature encompasses two common AVMs, angiodysplasia and hereditary hemorrhagic telangiectasia. Similarly, the bulk of information evaluates two therapies, hormones (estrogen and progesterone) and the somatostatin analogue octreotide. Of these, the former is the only therapy evaluated in randomized trials, and the results are conflicting without clear guidelines. The latter therapy has been reported only as case reports and case series without prospective trials. In addition, other anecdotally used medications are discussed.  相似文献   
33.
狂犬病病毒(RV)是一种高度嗜神经性病毒,由RV引发的狂犬病通常是一种急性致死性神经系统损伤性疾病。RV通过周围神经末梢和中枢神经系统(CNS)的神经元进行病毒的复制和传播。绝大多数狂犬病例CNS病理学表现为急性脑脊髓炎,常常没有显著的显微镜下改变,脑部可以轻度肿胀,脑膜和脑实质血管轻度充血并伴有少量炎症细胞浸润,这也是其他急性病毒性脑炎常见的共同表现。  相似文献   
34.
BACKGROUND: Although pedophilia is of high public concern, little is known about underlying neural mechanisms. Although pedophilic patients are sexually attracted to prepubescent children, they show no sexual interest toward adults. This study aimed to investigate the neural correlates of deficits of sexual and emotional arousal in pedophiles. METHODS: Thirteen pedophilic patients and 14 healthy control subjects were tested for differential neural activity during visual stimulation with emotional and erotic pictures with functional magnetic resonance imaging. RESULTS: Regions showing differential activations during the erotic condition comprised the hypothalamus, the periaqueductal gray, and dorsolateral prefrontal cortex, the latter correlating with a clinical measure. Alterations of emotional processing concerned the amygdala-hippocampus and dorsomedial prefrontal cortex. CONCLUSIONS: Hypothesized regions relevant for processing of erotic stimuli in healthy individuals showed reduced activations during visual erotic stimulation in pedophilic patients. This suggests an impaired recruitment of key structures that might contribute to an altered sexual interest of these patients toward adults.  相似文献   
35.
The mechanism of release from sustained-release adinazolam mesylate tablets was assessed by the Higuchi equation and by analysis of drug release profiles through 60% released using the Peppas equation. Computed values of the diffusional exponent, n, ranged from 0.59 to 0.66. Values of n in this range are consistent with a mixed mechanism of release, with diffusion of drug through the hydrated polymer matrix and relaxation of this matrix being the principal processes controlling release. The rate of in vitro drug release was increased for half tablets relative to whole tablets and is attributed to an increase in the surface to volume ratio of half tablets of about 16%. This increase in surface-to-volume ratio of half tablets was reflected by an increase in the constant, k, from the Peppas equation of 20–23% and by an increase in the slope of Higuchi plots of 12–18% for four lots of tablets. In vivo/in vitro relationships from two bioavailability studies were thoroughly evaluated. Using either a linear or a quadratic relationship, an in vivo/in vitro correlation exists for sustained-release adinazolam mesylate tablets.  相似文献   
36.
Between 23 and 70% of occupants involved in frontal impacts sustain cervical spine injuries, many with neurological involvement. It has been hypothesized that cervical spinal cord compression and injury may explain the variable neurological profile described by frontal impact victims. The goals of the present study, using a biofidelic whole cervical spine model with muscle force replication, were to quantify canal pinch diameter (CPD) narrowing during frontal impact and to evaluate the potential for cord compression. The biofidelic model and a sled apparatus were used to simulate frontal impacts at 4, 6, 8, and 10 g horizontal accelerations of the T1 vertebra. The CPD was measured in the intact specimen in the neutral posture (neutral posture CPD), under static sagittal pure moments of 1.5 Nm (pre-impact CPD), during dynamic frontal impact (dynamic impact CPD), and again under static pure moments following each impact (post-impact CPD). Frontal impact caused significant (P<0.05) dynamic CPD narrowing at C0-dens, C2-C3, and C6-C7. The narrowest dynamic CPD was observed at C0-dens during the 10 g impact and was 25.9% narrower than the corresponding neutral posture CPD. Interpretation of the present results indicate that the neurological symptomatology reported by frontal impact victims is most likely not due to cervical spinal cord compression. Cord compression due to residual spinal instability is also not likely.  相似文献   
37.
在过去的20多年中,对吸入麻醉药作用机制的合理解释大量增多,同时也提出了更多目前还不能回答的问题。Eger等提出了吸入麻醉药产生对伤害性刺激无体动反应的作用靶位可能是两个相距5埃的位点的假设,简称5埃理论。现就相关问题作一综述。  相似文献   
38.
目的 验证降糖灵 1号的降血糖作用。方法 以大、小白鼠为实验动物 ,分别与空白对照、高血糖对照及降糖甲片组和消渴丸组进行对照。研究降糖灵 1号对肾上腺素性和四氧嘧啶性高血糖的药理作用。结果 降糖灵 1号组除与消渴丸组对糖尿病差异无显著性意义 (P >0 0 5 )外 ,与其他各组差异均有显著性意义 (P <0 0 5 ,P <0 0 1)。结论 降糖灵 1号具有明显的降血糖作用  相似文献   
39.
中医情志的发生机制刍议   总被引:1,自引:0,他引:1  
在情志学说和脑主神明理论指导下对情志产生的生理机制作新的诠释。认为脑神的气化出入及整合作用是情志发生的生理基础 ;五脏所化的气血精津为情志发生的物质基础  相似文献   
40.
市场机制下政府调节与医疗管制制度框架的构建   总被引:4,自引:1,他引:3  
医疗机构分类管理的政策确定了我国医疗服务的市场取向.我国医疗市场服务因其特殊的技术经济特点也存在一般意义上的市场失灵,使政府管制这一非市场治理机制的产生与存在成为必要,以弥补与矫正市场缺陷,保证医疗服务市场的规范运行和卫生改革的顺利推进.  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