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   32951篇
  免费   2046篇
  国内免费   2096篇
耳鼻咽喉   611篇
儿科学   264篇
妇产科学   104篇
基础医学   2975篇
口腔科学   3566篇
临床医学   3755篇
内科学   721篇
皮肤病学   39篇
神经病学   5175篇
特种医学   1504篇
外国民族医学   2篇
外科学   9115篇
综合类   5088篇
现状与发展   3篇
预防医学   632篇
眼科学   143篇
药学   1630篇
  16篇
中国医学   1196篇
肿瘤学   554篇
  2024年   124篇
  2023年   615篇
  2022年   847篇
  2021年   1124篇
  2020年   1130篇
  2019年   985篇
  2018年   957篇
  2017年   1043篇
  2016年   1078篇
  2015年   1148篇
  2014年   2160篇
  2013年   2278篇
  2012年   1948篇
  2011年   1977篇
  2010年   1799篇
  2009年   1641篇
  2008年   1531篇
  2007年   1671篇
  2006年   1545篇
  2005年   1288篇
  2004年   1133篇
  2003年   1102篇
  2002年   955篇
  2001年   737篇
  2000年   592篇
  1999年   583篇
  1998年   537篇
  1997年   492篇
  1996年   386篇
  1995年   354篇
  1994年   335篇
  1993年   288篇
  1992年   271篇
  1991年   214篇
  1990年   199篇
  1989年   218篇
  1988年   156篇
  1987年   149篇
  1986年   205篇
  1985年   302篇
  1984年   234篇
  1983年   180篇
  1982年   152篇
  1981年   138篇
  1980年   129篇
  1979年   40篇
  1978年   44篇
  1977年   31篇
  1976年   18篇
  1975年   8篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
1.
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   
2.
《中国现代医生》2020,58(4):182-184+188
目的 探讨脊柱后路内固定术后硬膜外血肿的预防与护理体会。方法 遵照回顾性分析法选择我院2013年2 月~2018 年2 月纳入的60 例脊柱后路内固定术患者,依照不同理疗方式进行分组。其中30 例给予常规药物治疗作为对照组,另30 例除了常规治疗之外实施综合护理作为研究组,记录两组硬膜外血肿、腰椎术后血肿及颈椎术后血肿发生率,分别在干预前后进行生活质量评分(QOL)调查,出院时发放满意度调查问卷表,对比两组干预结果。结果 研究组血肿发生率为6.67%,明显低于对照组的20.00%(P<0.05)。干预前两组的食欲、精神、睡眠、疼痛及日常生活评分相比差异无统计学意义(P>0.05),干预后研究组的各项评分均高于对照组(P<0.05)。研究组对干预效果的满意度为90.00%,明显高于对照组的76.67%(P<0.05)。结论 护理干预运用于脊柱后路内固定中效果显著,能够有效减少硬膜外血肿的发生率,提升生活质量,促进病情稳定,患者满意度较高,可维持良好医患关系。  相似文献   
3.
《Journal of endodontics》2020,46(6):846-857
IntroductionThis study assessed the cleaning, shaping, and disinfection abilities of 2 instrumentation systems in molar root canals using a novel correlative analytical approach.MethodsThe root canals from extracted mandibular and maxillary molars with apical periodontitis were pair matched according to anatomic similarities as determined by micro–computed tomographic analysis and prepared with either XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n = 16) or Reciproc Blue (VDW, Munich, Germany) (n = 16) instruments and 2.5% sodium hypochlorite irrigation. Pre- and postpreparation micro–computed tomographic scans were used to identify and calculate the unprepared surface areas (shaping), which were histobacteriologically evaluated for the presence of residual bacteria (disinfection) and pulp tissue remnants (cleaning) in each canal third.ResultsUnprepared canal surface areas for XP-endo Shaper and Reciproc Blue in the full canal length were approximately 26% and 19% (P < .05), respectively (30% and 23% in the apical part of the canal, P > .05). Preparation with Reciproc Blue resulted in 37.5% canals free of bacteria in all sections examined and 56% in the apical sections only. XP-endo Shaper resulted in 44% canals free of bacteria in all sections, and 56% in the apical part of the canal only. Pulp tissue remnants were not observed in 31% (all canal sections) and 50% (apical canal sections) of specimens from both instrument systems. No significant differences were observed between instruments when comparing the amount of pulp tissue remnants and the number of cases negative for bacteria and tissue remnants (P > .05).ConclusionsAlthough the Reciproc Blue instrument had superior shaping ability in comparison with XP-endo Shaper, both systems performed similarly in cleaning and disinfecting root canals. Irregular canals and difficult-to-reach areas were not thoroughly cleaned and disinfected by any of the tested systems.  相似文献   
4.
《Journal of endodontics》2020,46(9):1317-1322
IntroductionThe purpose of this study is to evaluate the amount of residual obturation material of retroinstrumented surgically resected roots using controlled memory files and to evaluate the incidence of adverse treatment outcomes.MethodsThirty maxillary anterior teeth in human cadavers were selected, and nonsurgical root canal treatment was performed on these teeth. A standardized 4-mm osteotomy and a 3-mm root resection with as close to 0° bevel as possible were made on each tooth. A microsurgical diamond tip was used to create a 1- to 2-mm starting point for each retropreparation. A 25/06 and 30/06 VTaper 2H were bent at about 90° angle to mimic the clinical and anatomic restrictions and used to create a retropreparation to a depth of 14 mm. Micro–computed tomography scans were taken and analyzed for volume and percentage of residual obturation material at 5 and 10 mm. In addition, the incidences of instrument separation and crack and ledge formation in the teeth were recorded.ResultsThe median volume of residual obturation at 5 and 10 mm was 0.18 mm3 (interquartile range, 0.36 mm3) and 1.97 mm3 (interquartile range, 1.99 mm3), respectively. The overall incidence of file separation during retropreparation was 13.33% (4/30). Among the cases analyzed with micro–computed tomography, none showed crack or ledge formation.ConclusionsRetroinstrumentation of surgically resected roots using controlled memory files cleans the canal effectively with relatively low adverse treatment outcomes. Although this novel technique is limited in application, it is a safe and effective way to achieve a deep, clean retropreparation.  相似文献   
5.
6.
BACKGROUNDGuillain-Barré syndrome (GBS) is a rare disorder that typically presents with ascending weakness, pain, paraesthesias, and numbness, which mimic the findings in lumbar spinal stenosis. Here, we report a case of severe lumbar spinal stenosis combined with GBS.CASE SUMMARYA 70-year-old man with a history of lumbar spinal stenosis presented to our emergency department with severe lower back pain and lower extremity numbness. Magnetic resonance imaging confirmed the diagnosis of severe lumbar spinal stenosis. However, his symptoms did not improve postoperatively and he developed dysphagia and upper extremity numbness. An electromyogram was performed. Based on his symptoms, physical examination, and electromyogram, he was diagnosed with GBS. After 5 d of intravenous immunoglobulin (0.4 g/kg/d for 5 d) therapy, he gained 4/5 of strength in his upper and lower extremities and denied paraesthesias. He had regained 5/5 of strength in his extremities when he was discharged and had no symptoms during follow-up.CONCLUSIONGBS should be considered in the differential diagnosis of spinal disorder, even though magnetic resonance imaging shows severe lumbar spinal stenosis. This case highlights the importance of a careful diagnosis when a patient has a history of a disease and comes to the hospital with the same or similar symptoms.  相似文献   
7.
目的: 分析探讨加速康复外科(ERAS)理念在脊柱结核围手术期护理应用中的效果。 方法: 收集青岛市胸科医院外科2017年7月至2020年6月收治的147例脊柱结核患者。其中,2017年7月至2018年12月收治的68例脊柱结核手术患者围手术期应用常规护理,作为对照组;2019年1月至2020年6月收治的79例脊柱结核手术患者在常规护理措施基础上融入了ERAS理念,作为ERAS组。比较两组患者的引流管拔除、最初下床进行功能锻炼、最初自主排尿的时间,术后72h疼痛(采用视觉模拟评分法)评分,住院天数,恶心呕吐、肺部感染、药物性肝损伤的发生率,以及患者满意度的差异。 结果: 与对照组相比,ERAS组患者引流管拔除时间[6.00(4.00,8.00)d和8.00(7.00,8.00)d;W=4321.000,P<0.001]、最初下床进行功能锻炼时间[2.00(2.00,4.00)d和5.50(4.25,6.00)d;W=3376.000,P<0.001]、首次在床上自主排尿时间[5.00(3.00,6.00)h和9.00(7.00,9.00)h;W=3369.000,P<0.001]、术后72h疼痛评分[3.00(2.00,4.00)分和5.00(5.00,6.00)分;W=4078.500,P<0.001]、住院总天数[19.00(18.00,21.00)d和22.00(19.00,27.00)d;W=4791.500,P<0.001]均有所下降,差异均有统计学意义。与对照组相比,ERAS组术后恶心呕吐发生率[7.6%(6/79)和19.1%(13/68);χ2=4.311,P=0.038]、肺部感染发生率[2.5%(2/79)和11.8%(8/68);χ2=4.914,P=0.027]、药物性肝损伤发生率[1.3%(1/79)和13.2%(9/68),χ2=8.258,P=0.004]均有所下降,差异均有统计学意义。ERAS组患者满意度高于对照组[96.2%(76/79)和85.3%(58/68),χ2=7.100,P=0.008],差异有统计学意义。 结论: ERAS理念应用于脊柱结核围手术期护理可以加速患者的康复,减少并发症的发生,提高患者的满意度。  相似文献   
8.
《Clinical neurophysiology》2021,132(12):3104-3115
ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.  相似文献   
9.
10.
ObjectiveTo analyze the incidence and characteristics of traumatic spinal cord injury (SCI) in geriatric population of Galicia (Spain), hospital management and functional prognosis.MethodsComparative retrospective study. Patients admitted with acute traumatic SCI during the time period between January 2010 and December 2016 were included. Two groups established: The elderly over and under 75 years of age, with the latter acting as a control group.ResultsThree hundred seventy-nine patients were studied (27.2% ≥75 years). The main etiology in the >75 years group were falls: 80.6%. There were 65.7% who presented incomplete spinal cord injuries with mean motor index (MI) of 44.9/100. Upon discharge, 90.8% were dependent. Hospital mortality was 34.9%. Those >75 years suffered from more cervical injuries (74.8 vs. 51.2%; p<0.001), longer delay in diagnosis (31.1 vs. 9.2%; p<0.001) and higher hospital mortality (34.9 vs. 3.2%; p<0.001). Fewer surgical interventions were performed, with a longer delay. Percentages for admission into ICU, mechanical ventilation and performing a tracheostomy proved to be similar. There were no significant differences found in the evolution according to the ASIA scale or the MI.Conclusions1) The frequency of traumatic SCI in the elderly in Galicia is high; 2) Neurological evolution is similar to younger patients but the level of dependence is higher; 3) The level of care provided is similar in both groups, except for the surgical indication, and 4) Hospital mortality is high.  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