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   52006篇
  免费   3732篇
  国内免费   2384篇
耳鼻咽喉   1740篇
儿科学   834篇
妇产科学   408篇
基础医学   6276篇
口腔科学   1450篇
临床医学   4666篇
内科学   4736篇
皮肤病学   363篇
神经病学   9792篇
特种医学   2373篇
外国民族医学   2篇
外科学   7705篇
综合类   5749篇
现状与发展   1篇
一般理论   2篇
预防医学   3619篇
眼科学   2600篇
药学   2985篇
  18篇
中国医学   1117篇
肿瘤学   1686篇
  2024年   46篇
  2023年   731篇
  2022年   929篇
  2021年   1591篇
  2020年   1822篇
  2019年   1689篇
  2018年   1543篇
  2017年   1839篇
  2016年   1857篇
  2015年   1787篇
  2014年   3061篇
  2013年   3300篇
  2012年   2590篇
  2011年   2850篇
  2010年   2432篇
  2009年   2303篇
  2008年   2471篇
  2007年   2560篇
  2006年   2305篇
  2005年   2080篇
  2004年   1929篇
  2003年   1835篇
  2002年   1522篇
  2001年   1306篇
  2000年   1092篇
  1999年   992篇
  1998年   843篇
  1997年   760篇
  1996年   575篇
  1995年   700篇
  1994年   633篇
  1993年   585篇
  1992年   625篇
  1991年   526篇
  1990年   473篇
  1989年   403篇
  1988年   376篇
  1987年   338篇
  1986年   338篇
  1985年   461篇
  1984年   386篇
  1983年   260篇
  1982年   286篇
  1981年   254篇
  1980年   235篇
  1979年   147篇
  1978年   127篇
  1977年   107篇
  1976年   80篇
  1975年   43篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
61.
62.
63.
The aim of this study was to describe a perineural ultrasound-guided infiltration technique for management of radial tunnel syndrome and to report its preliminary results in 54 patients. A mixture of a saline solution, a local anesthetic, and a corticosteroid solution was infiltrated in the perineural region at the arcade of Frohse. Pain was reported in 100% of patients before the procedure versus 1.9% after the procedure. Scratch collapse and Cozen test results were positive in 98.1% and 66.7% of patients before infiltration, respectively, versus 5.6% and 9.2% after infiltration. All variables had statistically significant differences between preprocedure and postprocedure evaluations (P < .01).  相似文献   
64.
《Clinical neurophysiology》2020,131(4):951-957
ObjectiveTo establish a noninvasive method to measure the neuromagnetic fields of the median nerve at the carpal tunnel after electrical digital nerve stimulation and evaluate peripheral nerve function.MethodsUsing a vector-type biomagnetometer system with a superconducting quantum interference device, neuromagnetic fields at the carpal tunnel were recorded after electrical stimulation of the index or middle digital nerve in five healthy volunteers. A novel technique for removing stimulus-induced artifacts was applied, and current distributions were calculated using a spatial filter algorithm and superimposed on X-ray.ResultsA neuromagnetic field propagating from the palm to the carpal tunnel was observed in all participants. Current distributions estimated from the magnetic fields had five components: leading and trailing components parallel to the conduction pathway, outward current preceding the leading component, inward currents between the leading and trailing components, and outward current following the trailing component. The conduction velocity and peak latency of the inward current agreed well with those of sensory nerve action potentials.ConclusionRemoving stimulus-induced artifacts enabled magnetoneurography to noninvasively visualize with high spatial resolution the electrophysiological neural activity from the palm to the carpal tunnel.SignificanceThis is the first report of using magnetoneurography to visualize electrophysiological nerve activity at the palm and carpal tunnel.  相似文献   
65.
66.
《Clinical neurophysiology》2020,131(8):1896-1901
ObjectiveWe retrospectively investigated the utility of the central motor conduction time (CMCT) in detecting upper motor neuron (UMN) involvements in patients with amyotrophic lateral sclerosis (ALS).MethodsFifty-two ALS patients and 12 disease control patients participated in this study. Surface electromyograms were recorded from the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles. We stimulated the motor cortex, brainstem, and spinal nerve using transcranial magnetic stimulation (TMS) in order to measure the cortical, brainstem, and spinal latencies. We divided the ALS patients into 2 subgroups (with UMN impairment vs. without UMN impairment) and calculated the rates of abnormal CMCT prolongation judged by their comparison with the normal ranges obtained by the measurement in the control patients.ResultsThe CMCTs in the FDI and TA were abnormally prolonged in over 40% of the ALS patients with UMN impairment and in nearly 30% of those without UMN impairment.ConclusionsCMCT shows UMN dysfunction in ALS patients without clinical UMN impairment.SignificanceTMS still has diagnostic utility in a significant portion of ALS patients.  相似文献   
67.
68.
BACKGROUND/OBJECTIVESAlthough some juices affect subjective sleep quality, there is a lack of information on the effect of a specific juice on objective sleep quality and heart rate variability (HRV) during sleep; thus the present study investigated whether a blended juice made from natural extracts influenced sleep quality and HRV during sleep in adults with disturbed sleep.SUBJECTS/METHODSA randomized, crossover study was conducted on twenty-five adults (15/10, female/male) complaining of difficulty initiating or maintaining nighttime sleep (Pittsburgh sleep quality index [PSQI] ≥ 5). During feeding sessions (FS), subjects received sleep-inducing juice made of natural ingredients (250 mL/trial) twice a day for 8 weeks or non-FS (N-FS) for 8 weeks while maintaining normal activities. Sleep quality and parameters were recorded via wearable actigraph for 7 consecutive days, and PSQI scores were assessed before and after the intervention. HRV was also monitored at rest and during sleep.RESULTSAfter receiving the sleep-inducing juice intervention (FS), PSQI scores were significantly decreased (P < 0.001) and correlated with a significant decline in fatigue severity scale and visual analogue scale levels (P < 0.05; both). HRV indices of vagal activity were significantly improved during FS (P < 0.05), and no significant differences in N-FS were observed. Sleep efficiency and total sleep time increased significantly (P < 0.05) and sleep latency, total counts, sleep fragmentation index, and movement index, decreased significantly (P < 0.05, all 4) during FS, with no significant differences-observed during N-FS.CONCLUSIONSThis study results demonstrated that an 8-week course of sleep-inducing juice has led to improve sleep quality, suggesting an enhanced cardiac vagal tone during sleep. Thus, it could be a well-tolerated option for adults with disturbed sleep.  相似文献   
69.
目的探讨1例输入性、家庭聚集性严重急性呼吸综合征冠状病毒2(SARS-CoV-2)感染的2个月龄新型冠状病毒疾病(COVID-19)婴儿的临床流行病学资料及影像学资料特点,并进行文献复习。 方法选择2020年2月7日,四川省金堂县第一人民医院收治的2个月龄COVID-19婴儿为研究对象。采用回顾性分析方法,收集该例婴儿的临床病例资料,对其临床流行病学特点、影像学资料、诊断、治疗方案及预后进行分析。本研究对报道COVID-19婴儿的相关文献进行复习,设定检索策略为:以"婴儿""新型冠状病毒肺炎""新型冠状病毒疾病""2019-nCoV""NCP""SARS-CoV-2""COVID-19""infant"等为关键词,在PubMed、Medline、中国知网、维普中文科技期刊数据库、万方数据知识服务平台,以及"医学界儿科频道"等公众平台及新闻网站中,检索相关文献,检索时间设定为2019年12月1日至2020年2月21日。总结符合本研究纳入、排除标准的文献中报道的COVID-19婴儿临床特点及其诊断、治疗方案与预后。本研究遵循的程序符合2013年修订的《世界医学协会赫尔辛基宣言》要求。 结果①病史采集、诊断、治疗结果:患儿,男性,生后2个月+29 d;2020年1月18日,患儿姨妈自武汉返蓉,密切接触后,患儿出现气促、轻微咳嗽、腹泻等症状。入院后,患儿检查结果显示,肺炎支原体及衣原体、甲型及乙型流感病毒抗原均呈阴性。胸部CT检查结果显示,患儿双肺胸膜下多发性浅淡磨玻璃病灶。2次鼻咽拭子SARS-CoV-2核酸检测均呈阳性。根据流行病学史、临床与影像学表现及核酸检测结果,确诊为普通型COVID-19患儿。经过对症治疗后,患儿气促、咳嗽临床症状消失,胸部影像学检查结果显示,肺部炎症病灶吸收,SARS-CoV-2核酸检测呈阴性。目前,患儿继续观察中,等候出院。②文献复习结果:按照本研究设定的文献检索策略,共计检索出5篇国内有关婴儿COVID-19文献及2篇婴儿COVID-19新闻报道,涉及18例COVID-19婴儿的临床特点、诊断、治疗方案及预后等研究。这18例COVID-19婴儿,均具有家庭聚集性、输入性感染特点(武汉COVID-19患者接触史)。其中,3例新生儿及其母亲均为SARS-CoV-2感染者。出生后,对2例新生儿进行有效隔离,无感染者接触史。这18例COVID-19婴儿的首发症状为:发热5例(27.8%)、咳嗽及下呼吸道症状3例(16.7%)、打喷嚏及吐奶1例(5.6%)、无症状3例(16.7%)、病史不详6例(33.3%)。其中,7例婴儿文献报道胸部CT检查结果,并且均存在异常,表现为双肺或单侧肺纹理增粗、磨玻璃影和(或)实变影。除2例婴儿未报道预后情况外,其余16例婴儿均预后良好,无死亡病例报道。 结论文献报道的COVID-19婴儿及纳入本研究的1例婴儿,均具有输入性、家庭聚集性感染特点,而且对新生儿患者,目前尚不能排除母婴垂直传播可能性。对于临床症状相对较轻,肺部病变范围相对较小且局限的COVID-19婴儿,一般预后较好。在COVID-19暴发流行期,应尽可能加强儿童,特别是婴儿的防护,避免输入性、家庭聚集性SARS-CoV-2感染。  相似文献   
70.
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