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   241013篇
  免费   12965篇
  国内免费   7719篇
耳鼻咽喉   2830篇
儿科学   8456篇
妇产科学   3072篇
基础医学   18544篇
口腔科学   4275篇
临床医学   29795篇
内科学   40327篇
皮肤病学   3061篇
神经病学   15616篇
特种医学   12855篇
外国民族医学   23篇
外科学   38505篇
综合类   23068篇
现状与发展   27篇
预防医学   15259篇
眼科学   4457篇
药学   24985篇
  96篇
中国医学   4857篇
肿瘤学   11589篇
  2023年   2169篇
  2022年   5243篇
  2021年   10744篇
  2020年   5771篇
  2019年   11582篇
  2018年   6159篇
  2017年   5502篇
  2016年   7483篇
  2015年   10396篇
  2014年   18895篇
  2013年   16823篇
  2012年   19789篇
  2011年   16681篇
  2010年   15346篇
  2009年   14853篇
  2008年   13444篇
  2007年   13562篇
  2006年   11509篇
  2005年   7718篇
  2004年   4106篇
  2003年   3678篇
  2002年   3008篇
  2001年   2383篇
  2000年   2095篇
  1999年   1417篇
  1998年   1886篇
  1997年   1747篇
  1996年   1405篇
  1995年   1439篇
  1994年   1375篇
  1993年   1082篇
  1992年   1327篇
  1991年   1156篇
  1990年   1220篇
  1989年   1200篇
  1988年   1053篇
  1987年   966篇
  1986年   844篇
  1985年   1827篇
  1984年   1940篇
  1983年   1409篇
  1982年   1478篇
  1981年   1445篇
  1980年   1248篇
  1979年   1012篇
  1978年   791篇
  1977年   786篇
  1976年   673篇
  1974年   459篇
  1973年   442篇
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
71.
 Û   ¬  ࿞ ¿   ¬ í  &#x; ྽   &#x;         &#x; 《中国肺癌杂志》2021,24(3):161
背景与目的以免疫检查点抑制剂(immune checkpoint inhibitors, ICIs)为代表的免疫治疗越来越广泛地应用于肺癌治疗。然而,对于程序性死亡受体配体1(programmed cell death-ligand 1, PD-L1)高表达,即肿瘤比例评分(tumor proportion score, TPS)≥50%的晚期非小细胞肺癌(non-small cell lung cancer, NSCLC)患者,采用单纯免疫治疗还是免疫联合化疗在临床上仍存争议。本研究旨在评估PD-L1高表达的晚期NSCLC患者接受单纯免疫治疗与免疫联合化疗的疗效。方法本研究回顾性分析了49例PD-L1高表达晚期NSCLC患者的临床资料。PD-L1表达采用22C3抗体行免疫组化染色,按TPS判读PD-L1表达水平。比较不同临床特征分组患者的客观缓解率(objective response rate,ORR)和无进展生存时间(progression free survival, PFS)。结果免疫单药与免疫联合化疗组的ORR分别为47.1%(8/17)和43.8%(14/32),差异无统计学意义(P=0.825)。免疫单药与免疫联合化疗组的中位PFS分别为8.0个月和6.8个月,差异无统计学意义(P=0.502)。并对本组PD-L1高表达患者免疫治疗的预测因素进行了分析,结果显示,一线免疫治疗ORR(12/19, 63.2%)显著优于二线及以上免疫治疗(10/30, 33.3%),差异有统计学意义(P=0.041),二者间PFS无差异。年龄、性别、吸烟史、功能状态评分(performance status, PS)、病理类型、肿瘤大小、肿瘤淋巴结转移(tumor node metastasis, TNM)分期与ORR和PFS不相关。结论PD-L1高表达的晚期NSCLC患者接受免疫单药和免疫联合化疗的疗效相近。PD-L1高表达患者一线免疫治疗的ORR更佳。对此类人群的最佳治疗方案有待于前瞻性临床研究进一步探索。  相似文献   
72.
《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   
73.
《Clinical neurophysiology》2019,130(12):2231-2237
ObjectiveThe clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients.MethodsWe performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC).ResultsTwenty-four patients (aged 3–35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ± 1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group.ConclusionsThese neurophysiological findings suggest a subcortical generator of myoclonus in AS.SignificanceMyoclonus in AS has not a cortical origin as previously hypothesised.  相似文献   
74.
目的研究分析连续护理干预模式对脊柱骨折伴脊髓损伤患者术后康复效果。方法本项研究回顾了2017年2月—2018年7月间在某院采取了脊柱骨折伴脊髓损伤治疗的52例患者整个治疗过程的资料,将所有的患者使用数字双盲法将其分为了对照组(n=26)和观察组(n=26)。对照组患者使用护理措施为常规护理措施,观察组使用的护理措施为连续护理干预模式,在患者治疗完成后对比两个不同组别患者在围手术期期间各类指标和出现并发症概率。结果对照组患者手术下床活动时间、住院时间、住院所需费用以及患者并发症发生率均显著高于观察组,组别间数据对比差异具有统计学意义(P<0.05)。结论医护人员在进行脊柱骨折伴脊髓损伤患者的护理工作当中,对其采取连续护理模式可以降低患者并发症发生率,缩短患者住院时间,对患者身体的恢复具有显著意义。  相似文献   
75.
目的 探讨PDCA 循环在消化道肿瘤伴糖尿病患者营养全程管理中的效果观察。方法 运用PDCA循环对80例不同程度营养不良的消化道肿瘤伴糖尿病患者实施营养全程管理,比较干预前后患者的体重、BMI指数、糖化血红蛋白、血红蛋白、总蛋白、白蛋白及球蛋白水平。结果 患者血红蛋白、总蛋白、白蛋白及球蛋白水平均有提高,比较差异均有统计学意义(P<0.05)。结论 PDCA循环管理在消化道肿瘤伴糖尿病患者营养全程管理中有较大的优势, 值得推广。  相似文献   
76.
77.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
78.
目的对中国精神分裂症患者采取家庭干预的研究文献进行综合回顾和系统评价, 比较不同条件下家庭干预效果的差异。方法在中国知网、维普、万方、中国生物医学文献数据库四大中文数据库及OVID Medline、Science Direct、Web of Science、EBSCO四大英文数据库中, 检索各数据库建库至2015年1月为止使用社会功能缺陷筛选量表(SDSS)、简明精神病(科)量表(BPRS)、阳性与阴性症状量表(PANSS)研究中国精神分裂症患者家庭干预效果的文献, 以标准化加权均数差( SMD)作为效应量, 采用meta分析比较不同干预时间、不同干预类型、对不同病程和不同严重程度的精神分裂症患者的家庭干预效果差异。 结果共纳入57篇符合标准的文献。SDSS、PANSS分析结果显示:① 干预时间越长干预效果越好( P < 0.0001、 P=0.0025);② 单独家庭干预比多个家庭合并单独家庭干预的效果更明显( P < 0.0001、 P=0.0131);③ 干预对于病情较重患者效果较好( P < 0.0001、 P=0.0280)。SDSS量表还显示家庭干预对于病程短的患者效果更好( P < 0.0001)。 结论家庭干预更适合病程较短的精神分裂症患者, 干预应实施较长时间; 单独家庭干预更有利于患者阴性症状的改善和社会功能的康复, 且对于病情较轻患者的阴性症状改善效果更好。  相似文献   
79.
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   
80.
ObjectivesThis study aimed to determine the effect of lower leg compression during cesarean section (CS) on post-spinal hypotension (PSH) and neonatal hemodynamic parameters.MethodsThis study is a nonrandomized controlled clinical trial conducted in the cesarean delivery unit of the National Medical institute, Damanhour, Egypt. The sample included 120 parturients (60 intervention and 60 control). The researchers developed three tools for data collection: sociodemographic data and reproductive history interview schedule, electronic monitoring of maternal hemodynamic parameters, and neonatal hemodynamic assessment sheet. All parturients received ordinary pre-operative care. For the intervention group, a long elastic stocking (ordinary pressure 20–30 mmHg, 1 mmHg = 0.133 kPa) was applied on both legs during cesarean section. The control group received the same care without the elastic stocking.ResultsSystolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were significantly higher in the intervention group throughout the entire operation period except in the last 5–15 min. Heart rate was significantly lower in the intervention group. Only 13.3% of the intervention group took ephedrine compared with 45% of the control group. Apgar score was higher among neonates of intervention group compared with the control group at 1 min. Neonatal acidosis was significantly higher in the control group than in the contral group.ConclusionLower leg compression technique can effectively reduce PSH and neonatal acidosis.  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