全文获取类型
收费全文 | 19972篇 |
免费 | 1884篇 |
国内免费 | 263篇 |
专业分类
耳鼻咽喉 | 178篇 |
儿科学 | 523篇 |
妇产科学 | 228篇 |
基础医学 | 1475篇 |
口腔科学 | 525篇 |
临床医学 | 2077篇 |
内科学 | 2066篇 |
皮肤病学 | 265篇 |
神经病学 | 1888篇 |
特种医学 | 653篇 |
外科学 | 1307篇 |
综合类 | 1852篇 |
一般理论 | 1篇 |
预防医学 | 1049篇 |
眼科学 | 5907篇 |
药学 | 1298篇 |
2篇 | |
中国医学 | 388篇 |
肿瘤学 | 437篇 |
出版年
2024年 | 56篇 |
2023年 | 431篇 |
2022年 | 628篇 |
2021年 | 1093篇 |
2020年 | 892篇 |
2019年 | 908篇 |
2018年 | 966篇 |
2017年 | 899篇 |
2016年 | 850篇 |
2015年 | 798篇 |
2014年 | 1517篇 |
2013年 | 1572篇 |
2012年 | 1191篇 |
2011年 | 1236篇 |
2010年 | 945篇 |
2009年 | 921篇 |
2008年 | 994篇 |
2007年 | 863篇 |
2006年 | 699篇 |
2005年 | 549篇 |
2004年 | 469篇 |
2003年 | 371篇 |
2002年 | 274篇 |
2001年 | 263篇 |
2000年 | 220篇 |
1999年 | 193篇 |
1998年 | 194篇 |
1997年 | 157篇 |
1996年 | 147篇 |
1995年 | 140篇 |
1994年 | 128篇 |
1993年 | 117篇 |
1992年 | 117篇 |
1991年 | 81篇 |
1990年 | 79篇 |
1989年 | 74篇 |
1988年 | 99篇 |
1987年 | 76篇 |
1986年 | 68篇 |
1985年 | 117篇 |
1984年 | 98篇 |
1983年 | 82篇 |
1982年 | 83篇 |
1981年 | 79篇 |
1980年 | 82篇 |
1979年 | 55篇 |
1978年 | 47篇 |
1977年 | 42篇 |
1976年 | 48篇 |
1975年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
M. E. J. van Velthoven M. D. de Smet R. O. Schlingemann M. Magnani F. D. Verbraak 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2006,244(9):1119-1123
Background Evaluating the presence of leakage on fluorescein angiography (FA) in patients with age-related macular degeneration (AMD) retreated with photodynamic therapy (PDT) can be difficult. New diagnostic tools such as optical coherence tomography (OCT) might help to optimize PDT management.Methods Thirty AMD patients scheduled for regular follow-up FA in conjunction with PDT treatment were also scanned with OCT. Follow-up data at 9 months were retrieved from the patients’ medical records. Inter-observer agreement [kappa (κ) coefficient] for the presence of leakage on FA, for OCT parameters for leakage, and agreement between FA and OCT evaluations were calculated. The indication for retreatment was evaluated using the leakage analysis based on FA alone, OCT alone, and both examinations combined, and compared to the actual follow-up of the patients at 9 months.Results Agreement between the two observers for the presence of leakage on FA was moderate (κ=0.51). OCT agreement between the two observers for the presence of leakage was good (κ=0.85). Agreement between FA and OCT for the presence of leakage was poor (κ=0.16). Follow-up data at 9 months on all patients were analyzed. Seven out of 30 patients were not retreated at the time of examination, and four of these patients (57%) remained stable without further treatment. Twenty-three patients did receive a PDT treatment at the time of examination; and eight of these patients did not show leakage on OCT, and five of these patients (62%) remained stable without additional treatment. In contrast, only three out of 15 patients (20%) with leakage on both FA and OCT remained stable during this 9 month follow-up period.Conclusions Inter-observer agreement for the presence of leakage was moderate for FA and good for OCT. There was considerable disagreement between leakage as judged by OCT and by FA. OCT could be of help in the decision regarding PDT retreatment. Assuming that 57% of the patients without leakage either on FA or OCT would remain stable without retreatment, the rate of probable ineffective retreatment could be reduced from 35% to 20%.There was no financial support for this study. The authors have full access to the data and will allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review the data if requeste.d 相似文献
82.
83.
辐照猪皮与金因肽联合在儿童烧伤创面治疗中的应用 总被引:1,自引:1,他引:0
目的:观察辐照猪皮与金因肽在儿童Ⅱ度烧伤治疗中的作用。方法:治疗组清创后应用辐照猪皮与金因肽覆盖创面;对照组应用磺胺嘧啶银锌霜+金因肽覆盖创面。临床选择65例患者(总共127个创面),包括浅、深Ⅱ度烧伤,临床观察创面愈合时间、应用辐照猪皮与金因肽对全身情况的影响,后期瘢痕增生情况。结果:治疗组比对照组创面愈合时间明显缩短,治疗组明显优于对照组(P〈0.05);患者未出现过敏反应和其他不良反应,后期随访瘢痕增生少。结论:辐照猪皮与金因肽联合治疗儿童Ⅱ度烧伤创面,可促进创面上皮化,明显缩短创面愈合时间,瘢痕增生少,疗效可靠。 相似文献
84.
85.
The aims of this study were (1) to elicit the users' responses to four electronic head-mounted devices (Jordy, Flipperport, Maxport and NuVision) and (2) to correlate users' opinion with performance. Ten patients with early onset macular disease (EOMD) and 10 with age-related macular disease (AMD) used these electronic vision enhancement systems (EVESs) for a variety of visual tasks. A questionnaire designed in-house and a modified VF-14 were used to evaluate the responses. Following initial experience of the devices in the laboratory, every patient took home two of the four devices for 1 week each. Responses were re-evaluated after this period of home loan. No single EVES stood out as the strong preference for all aspects evaluated. In the laboratory-based appraisal, Flipperport typically received the best overall ratings and highest score for image quality and ability to magnify, but after home loan there was no significant difference between devices. Comfort of device, although important, was not predictive of rating once magnification had been taken into account. For actual performance, a threshold effect was seen whereby ratings increased as reading speed improved up to 60 words per minute. Newly diagnosed patients responded most positively to EVESs, but otherwise users' opinion could not be predicted by age, gender, diagnosis or previous CCTV experience. User feedback is essential in our quest to understand the benefits and shortcoming of EVESs. Such information should help guide both prescribing and future development of low vision devices. 相似文献
86.
中枢神经细胞瘤5例报告及文献复习 总被引:1,自引:1,他引:0
目的探讨提高中枢神经细胞瘤诊疗水平的策略和方法。方法回顾分析2004年8月至2006年4月我院收治的5例中枢神经细胞瘤,总结其临床表现、影像学表现、病理学特征及显微外科手术治疗效果。结果肿瘤位于侧脑室前部或室间孔附近,呈宽基底与侧脑室壁或透明隔相连。肿瘤边缘及内部可见多发囊泡,常见钙化,MRI检查T1WI、T2WI相均表现为等或略高信号,增强后呈轻至中度强化。免疫组织化学染色均显示神经突触素阳性。显微外科手术治疗5例,其中全切除4例,次全切除1例,1例死于术后并发症,4例随访至今未复发。结论中枢神经细胞瘤影像学表现具有一定特征,是术前诊断的重要参考。显微手术切除肿瘤是最佳的治疗手段,预后良好。 相似文献
87.
目的通过测定开颅术后周围静脉血、皮下引流液及脑脊液中药物浓度,来评价开颅手术对脑脊液药物浓度的影响.方法开颅手术前半小时静脉滴注硫酸庆大霉素8万单位,6小时后分别测定周围静脉血、皮下引流液及脑脊液中庆大霉素浓度,分别对无需切开硬脑膜及需要切开硬脑膜的病例各20例进行对照观察.结果硬脑膜完整组:周围静脉血为0.47±0.15,皮下引流液为1.41±0.46,脑脊液0.27±0.18,以皮下引流液中浓度最高,周围静脉血其次,脑脊液最低,三者比较均有显著差异(P<0.01);硬脑膜开放组:周围静脉血为0.56±0.19,皮下引流液为1.28±0.75,脑脊液为0.52±0.15,亦是皮下引流液中浓度最高,但周围静脉血与脑脊液无显著差异(P>0.05).两组之间周围静脉血以及皮下引流液无显著差异(P>0.05),而脑脊液有显著差异(P<0.01).结论开颅术后的皮下引流液中含有较高的药物浓度,与脑脊液间存在着明显的浓度差,药物能通过脑脊液与皮下渗出液的交换而进入颅内,使脑脊液中的药物浓度上升. 相似文献
88.
目的:探讨应用自体刃厚头皮片移植厚中厚皮片供区以抑制瘢痕增生的可行性及应用效果。方法:烧伤后全身大范围的增生性瘢痕患者24例,行功能部位的增生性瘢痕切除,应用非功能部位的大张厚中厚皮片修复,厚中厚皮片供区应用刃厚头皮片移植修复。结果:24例患者非功能部位厚中厚皮片供区经刃厚头皮片移植后,未见有明显的瘢痕增生。经随访半年至2年11例,2年以上3例,均未见有明显的瘢痕增生。头皮片供区无瘢痕形成,头发生长良好。结论:应用自体刃厚头皮片移植厚中厚皮片供区抑制瘢痕增生是一种可行的方法,值得临床推广。 相似文献
89.
Sandra Harris 《Clinical & experimental optometry》2003,86(1):51-56
Age‐related macular degeneration is a major cause of serious vision loss. The earliest stages of age‐related maculopathy may be defined by the size of the drusen present in the macula and the effects on vision. Further manifestations may include soft drusen, choroidal neovascularisation, macular haemorrhage and cicatricial or disciform degeneration of the macula. This report describes a patient with a macular haemorrhage, a choroidal neovascular membrane and serious loss of vision. In addition, the pathogenesis, diagnosis and treat‐ment options of macular degeneration are reviewed. 相似文献
90.
Background: The slitlamp can be used to estimate the anterior chamber depth (ACD). The length of a slit object is increased until the corneal and iris/lens images appear to just touch. Multiplying the just‐touching‐slit‐length (JTSL) by a conversion factor gives an estimate of the ACD as measured by ultrasonography. The purpose of this study was to determine if central corneal thickness (CCT) affects the accuracy of this technique. Methods: The ACD of 50 subjects was measured by A‐scan ultrasonography and estimated by the slitlamp technique. CCT was measured by ultrasonic pachometry. The refractive error was determined subjectively. Results: The average ultrasonographic ACD for all subjects was 3.32 ± 0.65 mm. The average JTSL was 2.46 ± 0.38 mm. The conversion ratio between the ultrasonographic ACD and the average JTSL was 1.35. The predicted ACD using the regression equation of JTSL on the ultrasound anterior chamber depth (USACD) was 3.32 ± 0.54 mm. The corresponding value using the regression equation of JTSL and CCT on USACD was exactly the same, that is, 3.32 ± 0.54 mm. Conclusion: Incorporation of CCT into a regression equation does not improve the accuracy of the Smith technique. 相似文献