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   23901篇
  免费   2267篇
  国内免费   645篇
耳鼻咽喉   423篇
儿科学   286篇
妇产科学   672篇
基础医学   3465篇
口腔科学   241篇
临床医学   3108篇
内科学   2355篇
皮肤病学   121篇
神经病学   8902篇
特种医学   468篇
外科学   2108篇
综合类   1685篇
预防医学   668篇
眼科学   206篇
药学   1257篇
  3篇
中国医学   620篇
肿瘤学   225篇
  2023年   546篇
  2022年   676篇
  2021年   1658篇
  2020年   1346篇
  2019年   1098篇
  2018年   1019篇
  2017年   991篇
  2016年   853篇
  2015年   799篇
  2014年   1439篇
  2013年   1540篇
  2012年   1059篇
  2011年   1235篇
  2010年   981篇
  2009年   993篇
  2008年   1007篇
  2007年   952篇
  2006年   873篇
  2005年   730篇
  2004年   644篇
  2003年   628篇
  2002年   541篇
  2001年   404篇
  2000年   370篇
  1999年   331篇
  1998年   289篇
  1997年   270篇
  1996年   201篇
  1995年   214篇
  1994年   234篇
  1993年   171篇
  1992年   229篇
  1991年   182篇
  1990年   180篇
  1989年   167篇
  1988年   133篇
  1987年   135篇
  1986年   130篇
  1985年   207篇
  1984年   185篇
  1983年   142篇
  1982年   146篇
  1981年   138篇
  1980年   135篇
  1979年   120篇
  1978年   99篇
  1977年   75篇
  1976年   77篇
  1975年   47篇
  1974年   51篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的探讨短时程脊髓电刺激(temporary spinal cord stimulation, tSCS)治疗爆发痛合并触诱发痛的急性期带状疱疹的临床疗效。方法回顾性地分析同济大学附属第十人民医院疼痛科2020年1月—2020年12月收治的52例接受tSCS治疗的爆发痛合并触诱发痛的急性期带状疱疹患者的临床资料,评估在治疗前、治疗后3d、7d、14d、3个月、6个月的总体疼痛情况(numerical rating scale, NRS)评分、(simple McGill scores, McGill)评分、爆发痛情况(发生率、NRS评分、次数以及持续时间)、触诱发痛情况(发生率、分级)、术后不良反应等;评估在治疗前、治疗后7d、3个月、6个月的睡眠时长、睡眠中醒来次数、疼痛障碍指数(pain disorder index, PDI)、功能状态评分(Karnofsky score, KPS)、抑郁症筛查量表(patient health questionnaire depression module scale, PHQ-9)和焦虑症筛查量表(generalized anxiety disorder-7 scale, GAD-7)等。结果与治疗前相比,治疗后3d、7d、14d、3个月、6个月的总体疼痛NRS评分、总体疼痛MCGILL评分、静息痛NRS评分明显降低(均P<0.001);与治疗前相比,治疗后3d、7d、14d、3个月、6个月的的爆发痛NRS评分明显降低(均P<0.05),治疗后14d、3个月、6个月时的爆发痛次数以及持续时间都明显降低(均P<0.05);与治疗前比较,患者治疗后7d、14d、3个月、6个月时的触诱发痛的分级都明显降低,差异均有统计学意义(均P<0.05);与治疗前相比,治疗后14d、3个月、6个月的PDI评分明显降低(P<0.05);与治疗前相比,治疗后14d、3个月、6个月的PHQ-9评分和GAD-7评分都明显减少(P<0.05),与术前的药物使用情况相比,治疗后各镇痛药使用人数普遍呈下降趋势;术中及整个随访期间未观察到严重不良事件。结论短时程脊髓电刺激对爆发痛合并触诱发痛的急性期带状疱疹具有较好的临床疗效。  相似文献   
2.
《Clinical neurophysiology》2021,132(10):2357-2364
ObjectivesTo investigate the subcortical somatosensory evoked potentials (SEPs) to electrical stimulation of either muscle or cutaneous afferents.MethodsSEPs were recorded in 6 patients suffering from Parkinson’s disease (PD) who underwent electrode implantation in the pedunculopontine (PPTg) nucleus area. We compared SEPs recorded from the scalp and from the intracranial electrode contacts to electrical stimuli applied to: 1) median nerve at the wrist, 2) abductor pollicis brevis motor point, and 3) distal phalanx of the thumb. Also the high-frequency oscillations (HFOs) were analysed.ResultsAfter median nerve and pure cutaneous (distant phalanx of the thumb) stimulation, a P1-N1 complex was recorded by the intracranial lead, while the scalp electrodes recorded the short-latency far-field responses (P14 and N18). On the contrary, motor point stimulation did not evoke any low-frequency component in the PPTg traces, nor the N18 potential on the scalp. HFOs were recorded to stimulation of all modalities by the PPTg electrode contacts.ConclusionsStimulus processing within the cuneate nucleus depends on modality, since only the cutaneous input activates the complex intranuclear network possibly generating the scalp N18 potential.SignificanceOur results shed light on the subcortical processing of the somatosensory input of different modalities.  相似文献   
3.
ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation.  相似文献   
4.
5.
ObjectiveTo analyze the effects of electrolysis, through a medium frequency current, associated to aerobic physical activity in the body composition of young women.MethodsThe study was composed of 34 sedentary women (24.35 ± 4.43 years, 71.30 ± 7.08 kg, 1.61 ± 0.06 m, 27.31 ± 1.67 kg/m2) which were evaluated for their anthropometric measures and body composition. The volunteers were randomly assigned to two group: Electrolyphysis plus Aerobic Exercise (gEEA): 17 volunteers were submitted to the application, for 60 min , of the Aussie current, followed by aerobic physical activity (77% of HRmax) on the trampoline for 40 min, through video-lessons of Jump; and Aerobic Exercise group (gEA): 17 volunteers performed only physical activity following the same parameters mentioned above. Each group performed its protocols twice weekly, for 5 weeks, totaling 10 sessions. For the data analysis, measures repeated ANOVA was performed to compare the means of the variables analyzed before and after the treatment protocols using the SPSS - 21.0 software, adopting a p ≤ 0.05.ResultsAlthough gEEA decreased suprailiac skinfold (p = 0.04), abdominal skinfold (p = 0.03) and circumference at umbilical scar (p = 0.02) in an intragroup analysis, these means differences in anthropometric measures were not important between-groups (p > 0.05). Furthermore, there were no effect of treatment on body composition (p > 0.05).ConclusionTo this studied condition, our results suggested that application of medium frequency electrolysis did not enhance the losses on anthropometric measures and body composition.  相似文献   
6.
7.
对中医药防治新型冠状病毒肺炎临床研究方案注册情况进行分析,为提高相关研究设计质量提供参考和建议。检索中国临床试验注册中心网站(www.chictr.org.cn)以及美国临床试验注册中心网站(clinicaltrials.gov),以新型冠状病毒肺炎、2019-nCoV等为检索词,检索新型冠状病毒肺炎中医药相关临床研究方案。按照纳入排除标准筛选文献,并提取研究注册时间、研究目的、研究类型、申办单位、研究对象、样本量、干预措施、评价指标等数据,采用描述性分析方法。共纳入新型冠状病毒肺炎中医药相关研究方案49个,研究负责单位以湖北、北京、浙江等地医院或高等院校为主。研究具体实施单位属地集中在湖北、广东、浙江、河南等地医院。研究设计以干预性试验研究为主(共40个),其中随机平行对照研究30个,非随机对照试验7个,单臂研究2个,连续入组1个;观察性研究6个;卫生服务研究2个;预防性研究1个。总样本量30562例,单个研究样本量最大20000例,最小30例。49个方案的研究对象包括健康人群(3个)、隔离观察人群(1个)、疑似病例(10个)、确诊病例(31个)、康复期病例(4个)。31个拟纳入确诊病例的研究方案中,有16个研究未明确病情分级,3个研究明确排除危重症,4个研究纳入普通型,2个研究纳入轻型、普通型或重型,1个研究纳入轻型和普通型,1个研究纳入普通型或重型,3个研究纳入重型,1个研究纳入重症或危重症。评价的干预措施包括中成药(连花清瘟胶囊/颗粒、藿香正气滴丸/口服液、八宝丹、固表解毒灵、金蒿解热颗粒、复方鱼腥草合剂、金叶败毒颗粒、疏风解毒胶囊、双黄连口服液、痰热清注射液、血必净注射液、热毒宁注射液、喜炎平注射液)、汤药、太极拳疗法。主要疗效指标以退热时间、临床症状缓解、新型冠状病毒核酸转阴、重症转化率、胸部CT影像为主。结果表明中医药防治新冠肺炎的临床研究响应快速,当前注册方案涵盖了疾病预防、治疗和康复全过程。但存在人群定义不清,研究目标不明确,干预方案需要细化,疗效评价指标需要优化等问题;另外,需要考虑疫情救治的实际困难和工作负担,在符合医学伦理条件下,优化流程,提高研究方案的可操作性。  相似文献   
8.
《Brain stimulation》2020,13(4):1040-1050
BackgroundAchieving deep brain stimulation (DBS) dose equivalence is challenging, especially with pulse width tuning and directional contacts. Further, the precise effects of pulse width tuning are unknown, and recent reports of the effects of pulse width tuning on neural selectivity are at odds with classic biophysical studies.MethodsWe created multicompartment neuron models for two axon diameters and used finite element modeling to determine extracellular influence from standard and segmented electrodes. We analyzed axon activation profiles and calculated volumes of tissue activated.ResultsWe find that long pulse widths focus the stimulation effect on small, nearby fibers, suppressing distant white matter tract activation (responsible for some DBS side effects) and improving battery utilization when equivalent activation is maintained for small axons. Directional leads enable similar benefits to a greater degree. Reexamining previous reports of short pulse stimulation reducing side effects, we explore a possible alternate explanation: non-dose equivalent stimulation may have resulted in reduced spread of neural activation. Finally, using internal capsule avoidance as an example in the context of subthalamic stimulation, we present a patient-specific model to show how long pulse widths could help increase the biophysical therapeutic window.DiscussionWe find agreement with classic studies and predict that long pulse widths may focus the stimulation effect on small, nearby fibers and improve power consumption. While future pre-clinical and clinical work is necessary regarding pulse width tuning, it is clear that future studies must ensure dose equivalence, noting that energy- and charge-equivalent amplitudes do not result in equivalent spread of neural activation when changing pulse width.  相似文献   
9.
目的观察脑电仿生电刺激小脑顶核对脑梗死后认知功能障碍的影响,并探讨其可能的机制。方法选取脑梗死后并发认知功能障碍患者50例,随机分成治疗组与对照组各25例。2组患者均接受康复治疗及认知功能训练,治疗组同时加用脑电仿生电刺激进行干预。2组患者分别于治疗前后应用蒙特利尔认知评估量表(MoCA)、简易精神状态量表(MMSE)评定认知功能变化,采用经颅多普勒超声(TCD)评估颅内动脉血流动力学改变。结果治疗后2组患者MoCA评分、MMSE评分均较组内治疗前提高(P<0.05),且治疗组评分明显较对照组高,差异有统计学意义(P<0.05)。治疗后2组患者颅内动脉血流动力学较组内治疗前改善(P<0.05),且治疗组较对照组改善更显著,差异有统计学意义(P<0.05)。治疗组与对照组总有效率分别为92%和64%,差异有统计学意义(P<0.05)。结论脑电仿生电刺激小脑顶核可有效改善脑梗死患者的认知功能,其可能机制是通过改善患者的脑循环进一步改善认知功能。  相似文献   
10.
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