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   12445篇
  免费   763篇
  国内免费   185篇
耳鼻咽喉   106篇
儿科学   182篇
妇产科学   188篇
基础医学   542篇
口腔科学   337篇
临床医学   2354篇
内科学   754篇
皮肤病学   106篇
神经病学   324篇
特种医学   722篇
外科学   902篇
综合类   2841篇
一般理论   1篇
预防医学   1922篇
眼科学   272篇
药学   1028篇
  55篇
中国医学   427篇
肿瘤学   330篇
  2024年   30篇
  2023年   148篇
  2022年   341篇
  2021年   423篇
  2020年   427篇
  2019年   260篇
  2018年   294篇
  2017年   344篇
  2016年   388篇
  2015年   393篇
  2014年   995篇
  2013年   861篇
  2012年   967篇
  2011年   939篇
  2010年   739篇
  2009年   656篇
  2008年   683篇
  2007年   691篇
  2006年   607篇
  2005年   474篇
  2004年   372篇
  2003年   319篇
  2002年   236篇
  2001年   215篇
  2000年   194篇
  1999年   189篇
  1998年   125篇
  1997年   144篇
  1996年   104篇
  1995年   96篇
  1994年   89篇
  1993年   87篇
  1992年   63篇
  1991年   57篇
  1990年   44篇
  1989年   35篇
  1988年   33篇
  1987年   26篇
  1986年   29篇
  1985年   31篇
  1984年   22篇
  1983年   20篇
  1982年   42篇
  1981年   28篇
  1980年   23篇
  1979年   29篇
  1978年   26篇
  1977年   11篇
  1976年   12篇
  1975年   12篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
佛山市城区集体儿童健康状况调查分析   总被引:1,自引:0,他引:1  
目的了解佛山市城区集体儿童健康状况,以制定干预措施。方法采用随机整群抽样的方法,抽取本市城区共15间幼儿园,并对各间园所的儿童体检的资料数据进行整理和分析。结果佛山市集体儿童缺点总检出率为71.40%。其中私营幼儿园儿童缺点患病率明显高于事业单位的幼儿园(P<0.05),有显著性差异。儿童骨矿物质测定缺钙的检出率为13.73%。男女儿童无性别差异。结论今后继续加强对幼儿园的管理工作,私营的幼儿园管理工作是我们今后管理工作的重点,做好防治工作,降低患病率,增强儿童的身心健康。  相似文献   
32.
目的:研究芪丹煎剂有效成分超声法提取的最适条件.方法:利用正交试验设计,对水量、提取时间和提取次数进行分析,找出最适条件.按最适条件重复3次,考察重复性.结果:水量为14倍、提取时间为30min,提取次数为3次时有效成分的总含量最大,3次平行试验有效成分总含量RSD为0.86%.结论:超声法提取的最佳条件为:水量14倍、提取时间30min,提取次数3次.本方法重复性较好.  相似文献   
33.
The validity of a simple clinical classification of acute ischaemic stroke   总被引:6,自引:0,他引:6  
The aim of the study reported here was to test the validity of a simple clinical classification of acute ischaemic stroke (Oxfordshire Community Stroke Project, OCSP) in predicting the site and size of cerebral infarction on computed tomography (CT). Consecutive patients admitted to hospital with acute ischaemic stroke were prospectively identified and classified into one of four clinical syndromes according to the OCSP classification, blind to the result of CT. The CT brain scans were classified blind to the clinical features into those demonstrating: small, medium or large cortical infarcts; small or large subcortical infarcts in the anterior circulation territory; and posterior cerebral circulation territory infarcts. A total of 108 patients were included. A recent infarct was seen. on the CT scan in 91 patients (84%), and the clinical classification correctly predicted the site and size of the cerebral infarct in 80 of these (88%; 95% confidence interval 77–92%). The positive predictive value was best for large cortical infarcts (0.94) and worst for small subcortical infarcts (0.63). The OCSP clinical classification is a reasonably valid way of predicting the site and size of cerebral infarction on CT and can, therefore, be used very early after stroke onset before the infarct appears on the scan.  相似文献   
34.
肝炎和肝硬化患者胆囊超声改变的观察与分析   总被引:7,自引:0,他引:7  
目的 :研究肝炎肝硬化患者胆囊彩色B超声像图变化 ,并探讨其临床意义。方法 :采用彩色超声诊断仪对 139例肝炎和肝硬化患者及 4 2例非肝炎体检者进行胆囊超声检查。结果 :慢性肝炎、重型肝炎、肝硬化患者组与非肝炎对照组彩色B超胆囊异常率比较均差异显著 (P <0 .0 1)。重型肝炎、肝硬化组与慢性肝炎组之间胆囊异常率也存在明显的差异 (P <0 .0 5 )。结论 :慢性肝病患者胆囊异常与胆囊本身炎症无关。胆囊声像图的改变对判断肝脏实质性病变的严重程度及指导临床治疗有一定的参考价值。  相似文献   
35.
本文采用三氮唑核苷超声雾化吸入治疗喘憋性肺炎,并与静脉用药比较,结果表明:用药前及用药后末梢血象变化,雾化给药不影响血液系统,而且有助于红细胞、血红蛋白恢复正常,无论在止咳、平喘、肺部罗音及X线炎症吸收效果均明显优于静脉给药组(P<0.01),提示超声雾化吸入用于治疗呼吸道感染(ARI),可以取代静脉途经用药,其疗效快,安全方便,避免静脉用药所引起的不良反应。  相似文献   
36.
牟鑫 《医疗设备信息》2003,18(11):34-35
近年来,超声定量检查技术在临床的应用为心血管疾病患者的心功能评估提供了量化的依据,本文介绍了超声诊断仪的使用部分最新定量检查技术。  相似文献   
37.
目的:探讨超声在贲门失弛缓症诊断中的应用价值。方法:对临床拟诊为贲门失弛缓症病人首先采用超声检查,诊断贲门失弛缓症38例,同时进行了X线钡剂食管及胃肠造影,并与40例正常人进行了对照。结果:超声对贲门失弛缓症的诊断符合率为100%,失弛缓症的食管管径明显大于正常对照组(P<0.01),管壁厚度亦大于正常对照组(P<0.01)食管蠕动明显减弱,甚者消失,扩张的食管腔内见有潴留的内容物。结论:超声对贲门失弛缓症诊断具有重要的临床应用价值,可取代传统的X线钡剂造影检查。  相似文献   
38.
Examination is a cornerstone in the manual procedures leading to mobilisation/manipulation of the low back. The observer variation of the more specific segmental tests remains to be investigated. Two skilled specialists in manual medicine examined the segmental changes in the lumbar spine. The patients were unknown to the examiners and no information of the case history was given. All test results were recorded by an observer present in the room who ensured that no conversation was allowed during the examination. The primary outcome measures were the kappa values for each test. The matching was defined as acceptable (acc) within two neighbouring levels and perfect (per) on the same level. Intra-observer variation (tested in 33 patients and 10 subjects without low-back pain): The agreement between first and second segmental diagnosis examination was 70% (per) and 82% (per + acc). Kappa values were: segmental diagnosis 0.60 (per) and 0.70 (per + acc), multifidus test 0.51 (per) and 0.60 (per + acc), sideflexion 0.57 (per) and 0.69 (per + acc), and ventral flexion 0.31 (per) and 0.45 (per + acc). Inter-observer variation (tested in 60 patients): The agreement for segmental diagnosis between the examiner A and B was 42% (per) and 75% (per + acc). Kappa values were: segmental diagnosis 0.21 (per) and 0.57 (acc), multifidus test 0.12 (per) and 0.48 (acc), sideflexion 0.22 (per) and 0.45 (acc), and ventralflexion 0.22 (per) and 0.44 (acc). By manual tests, skilled examiners seem to be able to diagnose segmental dysfunctions in the low back. The clinical implication of these dysfunctions remains to be clarified.  相似文献   
39.
Summary: Tumors and cortical dysplasia are associated with epilepsy, but few studies have examined the coexistence of neoplasia and dysplasia in these patients. We studied 13 patients (age 4–29 years) with recurrent seizures of 1 month to 21-year' duration (median 72 months). Ten patients were aged <21 years. Imaging studies localized the lesion to the temporal lobe (10 patients), parietal lobe (2 patients), and frontal lobe (1 patient). Tumors included ganglioglioma (8 patients), dysembryoplastic neuroepithelial tumor (DNT) (3 patients), and low-grade as- trocytoma (2 patients). Cortical dysplasia, including atypical aggregates of neurons (6 patients), multifocal loss of the cortical laminar architecture (7 patients), and neurons in the molecular layer of the cortex (3 patients) were observed near but separate from the tumor. Coexistence of certain tumors with cortical dysplasia, most frequently observed in the pediatric population, suggests a hamar-tomatous/dysplastic nature of the neoplasms.  相似文献   
40.
Summary The present study was undertaken to investigate the involvement of the noradrenergic neurotransmission system in the ultra sonic callings emitted by rat pups separated from their mother and exposed to cold stimulation. The investigation was primarily performed by help of agents selectively affecting the -adrenoceptors: the 2-agonist clonidine, the 1-antagonist prazosin and the 2-antagonist idazoxan.Clonidine dose-dependently stimulated the amount of ultra sonic vocalization, an effect not solely dependent upon the effect of clonidine on body temperature. In a developmental study it was found that clonidine uniformly stimulated crying at all ages from 4 days of age up to 18 days of age, that is during the whole preweaning period. Clonidine stimulated ultrasonic crying in rat pups, devoid of presynaptic catecholamine (CA) neurons by combined pretreatment with the monoamine depletor, reserpine, and the inhibitor of CAsynthesis, -methyl-tyrosine. This finding suggested that the stimulating effect of clonidine on ultrasonic vocalization was mediated by postsynaptic adrenoceptors.In pups, 12 days of age, idazoxan blocked the effect of cold stimulation on ultra sonic crying, suggesting that 2-adrenoceptors, presumably postsynaptic ones, mediated this kind of stimulation. Idazoxan also antagonized the effect of clonidine, but only at a dose effective also in control pups. Prazosin had no effect on cold-stimulated crying, but antagonized the effect of clonidine, suggesting that the effect of clonidine was also mediated by 1-receptors. At 18 days of age, prazosin no longer antagonized the effect of clonidine, whereas the antagonizing action of idazoxan was reinforced.The age-dependent variation in responsiveness to the adrenergic drugs suggest maturational changes in the function of the CA-system occurring between 12–16 days of age.  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