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   224482篇
  免费   21104篇
  国内免费   11048篇
耳鼻咽喉   2620篇
儿科学   6417篇
妇产科学   2210篇
基础医学   36696篇
口腔科学   6648篇
临床医学   17844篇
内科学   31689篇
皮肤病学   5012篇
神经病学   12173篇
特种医学   5158篇
外国民族医学   125篇
外科学   36378篇
综合类   33361篇
现状与发展   56篇
一般理论   4篇
预防医学   5325篇
眼科学   4749篇
药学   15090篇
  41篇
中国医学   5704篇
肿瘤学   29334篇
  2024年   368篇
  2023年   3005篇
  2022年   5264篇
  2021年   7884篇
  2020年   7289篇
  2019年   7162篇
  2018年   7384篇
  2017年   7769篇
  2016年   8089篇
  2015年   8982篇
  2014年   13578篇
  2013年   15018篇
  2012年   12557篇
  2011年   14334篇
  2010年   12173篇
  2009年   11811篇
  2008年   12239篇
  2007年   12544篇
  2006年   11709篇
  2005年   10633篇
  2004年   9163篇
  2003年   7781篇
  2002年   6350篇
  2001年   5402篇
  2000年   4515篇
  1999年   3922篇
  1998年   3697篇
  1997年   3346篇
  1996年   3030篇
  1995年   2607篇
  1994年   2438篇
  1993年   1886篇
  1992年   1691篇
  1991年   1496篇
  1990年   1131篇
  1989年   1066篇
  1988年   1002篇
  1987年   774篇
  1986年   713篇
  1985年   922篇
  1984年   801篇
  1983年   542篇
  1982年   612篇
  1981年   484篇
  1980年   419篇
  1979年   305篇
  1978年   225篇
  1977年   177篇
  1976年   138篇
  1975年   51篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
Depigmented lesions may occur as postinflammatory sequelae of subacute cutaneous lupus erythematosus (SCLE), leading to great psychosocial impact. A 53‐year‐old male patient presented with post‐SCLE depigmented facial lesions after five years of disease stability. We proposed surgical treatment with melanocyte‐keratinocyte transplantation procedure (MKTP), and after five months the patient achieved 90% repigmentation, without Koebner phenomenon (KP). In theory, KP is a possible complication of MKTP procedure since the preparation of the receptor area involves the use of dermabrasion. In an attempt to avoid it, we suggest to maintain the treatment of the underlying disease and wait for a minimum period of disease stability before the procedure.  相似文献   
32.
BackgroundSkin cancer is a highly prevalent condition with a multifactorial etiology resulting from genetic alterations, environmental and lifestyle factors. In Brazil, among all malignant tumors, skin cancers have the highest incidences.ObjectiveTo retrospectively evaluate the incidence, prevalence and profile of basal cell carcinoma, squamous cell carcinoma and cutaneous melanoma in Campos dos Goytacazes and region.Methods:In total, 2,207 histopathological reports of a local reference hospital were analyzed between January 2013 and December 2015, of which 306 corresponded to the neoplasms studied.Results:Of the 306 reports evaluated, 232 basal cell carcinomas (75.9%), 55 squamous cell carcinomas (18%) and 19 cutaneous melanomas (6.5%) were identified. The face was the most involved anatomical site (58.8%) and women (51%) were the most affected gender. The temporal analysis revealed a decrease in the overall incidence of 3.4% from 2013 to 2014 and 5.4% from 2014 to 2015. There was a 10.1% increase in basal cell carcinomas and 38% in melanomas in this period; however, there was a decrease in the number of squamous cell carcinomas of 14.8% during the studied years.Study limitations:Some samples of cutaneous fragments had no identification of the anatomical site of origin.Conclusion:Research that generates statistical data on cutaneous tumors produces epidemiological tools useful in the identification of risk groups and allows the adoption of more targeted and efficient future prevention measures.  相似文献   
33.
Recent years have brought an enhanced understanding of keratinocyte contribution to cutaneous nociception. While intra‐epidermal nerve endings were classically considered as the exclusive transducers of cutaneous noxious stimuli, it has now been demonstrated that epidermal keratinocytes can initiate nociceptive responses, like Merkel cells do for the innocuous mechanotransduction. In the light of recent in vivo findings, this article outlines this paradigm shift that points to a not yet considered population of sensory epidermal cells.  相似文献   
34.
目的:探讨3D-CRT 低剂量区 V5体积的大小对非小细胞肺癌患者肺功能的影响。方法:收集我院肿瘤科2014年4月~2015年10月收治的46例首次行三维适形放射治疗且顺利完成治疗的非小细胞肺癌患者,对每例患者分别在治疗前以及治疗后的1、3个月进行肺功能检测,分析3D-CRT 低剂量区 V5体积的大小与肺功能变化之间的关系。结果:放疗后1个月的 FEV1%、FVC%值明显高于放疗前且差异均具有显著性。放疗后1个月、3个月的 DLCO%值明显低于放疗前,且放疗前的与放疗后3个月的差异具有显著性;V5≦45%、45%55%三组放疗前后的 FEV1%值和 FVC%值比较差异均不具有显著性。V5≦45%、45%55%三组放疗前后的 DLCO%值均呈逐渐下降趋势,且 V5>55%组的放疗前后 DLCO%值比较差异具有显著性。而 V5≦45%组和45%55%时,DLCO%值降低的趋势更加显著。  相似文献   
35.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
36.
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.

Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.

Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.

Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion.  相似文献   
37.
38.
39.
复杂性胸壁缺损的修复一直是一项极具挑战性的工作。肿瘤性复杂性胸壁缺损的修复决策及其执行困难是限制胸壁肿瘤治疗方法选择及影响预后的重要因素之一。皮瓣解剖学研究的深入、胸壁支持结构重建技术的进步、显微外科技术的发展、麻醉护理的发展、对综合治疗的重视和治疗手段的进步等,使传统认为不可切除的胸壁肿瘤得以彻底地切除和安全有效地修复,从而使与缺损修复相关的肿瘤切除及辅助治疗的禁忌证缩减到最小程度,有效地提高了胸壁肿瘤患者的生存质量,并很大程度上延长了生存率。作者以湖南省肿瘤医院整形外科15年565例胸壁肿瘤切除后修复重建的临床资料为依据,充实了胸壁肿瘤切除及修复的策略:(1)可靠的胸壁骨性支架重建;(2)有效的软组织修复;(3)麻醉及护理与手术团队的合作;(4)系统有序的综合治疗。并进一步明确了复杂胸壁肿瘤切除及重建的细节理念,包括胸部肿瘤治疗中加强多学科合作的密切性和科学性,整形外科医生参与肿瘤治疗整体规划的主动性和时机前移等。  相似文献   
40.
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