全文获取类型
收费全文 | 6347篇 |
免费 | 834篇 |
国内免费 | 140篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 131篇 |
妇产科学 | 23篇 |
基础医学 | 215篇 |
口腔科学 | 1篇 |
临床医学 | 304篇 |
内科学 | 834篇 |
皮肤病学 | 9篇 |
神经病学 | 52篇 |
特种医学 | 48篇 |
外国民族医学 | 1篇 |
外科学 | 87篇 |
综合类 | 795篇 |
一般理论 | 1篇 |
预防医学 | 153篇 |
眼科学 | 4007篇 |
药学 | 338篇 |
5篇 | |
中国医学 | 263篇 |
肿瘤学 | 21篇 |
出版年
2024年 | 34篇 |
2023年 | 173篇 |
2022年 | 256篇 |
2021年 | 430篇 |
2020年 | 302篇 |
2019年 | 267篇 |
2018年 | 340篇 |
2017年 | 300篇 |
2016年 | 312篇 |
2015年 | 279篇 |
2014年 | 407篇 |
2013年 | 447篇 |
2012年 | 387篇 |
2011年 | 397篇 |
2010年 | 324篇 |
2009年 | 271篇 |
2008年 | 323篇 |
2007年 | 300篇 |
2006年 | 213篇 |
2005年 | 181篇 |
2004年 | 162篇 |
2003年 | 129篇 |
2002年 | 122篇 |
2001年 | 121篇 |
2000年 | 83篇 |
1999年 | 72篇 |
1998年 | 83篇 |
1997年 | 57篇 |
1996年 | 46篇 |
1995年 | 44篇 |
1994年 | 31篇 |
1993年 | 32篇 |
1992年 | 24篇 |
1991年 | 24篇 |
1990年 | 41篇 |
1989年 | 21篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 23篇 |
1985年 | 38篇 |
1984年 | 40篇 |
1983年 | 26篇 |
1982年 | 33篇 |
1981年 | 23篇 |
1980年 | 18篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1970年 | 4篇 |
排序方式: 共有7321条查询结果,搜索用时 46 毫秒
1.
2.
目的 利用频域光学相干断层扫描深度增强(enhanced depth imaging spectral domain optical coherence tomography,EDI SD-OCT)观察糖尿病黄斑水肿(diabetic macular edema,DME)患者脉络膜厚度(choroidal thickness,CT)的变化及结构特点,探讨DME病变程度与CT的关系。方法 纳入2型糖尿病患者共123例204眼,其中69眼诊断为DME(DME组),135眼无黄斑水肿为对照组。DME眼依据OCT形态学特点进一步分为视网膜弥漫性增厚(diffuse retinal thickness,DRT)型(34眼)、黄斑囊样水肿(cystoid macular edema,CME)型(19眼)和浆液性视网膜脱离(serous retinal detachment,SRD)型(16眼),利用EDI-OCT分别测量黄斑中心凹下CT和以黄斑为中心上、下、鼻、颞500 μm、1000 μm、1500 μm、2000 μm处CT。结果 DME组黄斑中心凹下CT为(326.72±90.15)μm,对照组为(320.17±106.46)μm,两组之间无统计学差异,但黄斑中心凹下CT与视网膜厚度间具有明显正相关关系(r=0.270,P=0.025)。DME亚型CT分别为:DRT型(303.94±81.47)μm、CME型(304.42±73.98)μm和SRD型(401.63±88.80)μm,SRD型CT明显高于其他亚型(P<0.05),此外,SRD型的周边CT同样呈现均匀一致的增厚;鼻侧CT从500 μm至2000 μm呈距离敏感性降低(P<0.05),但SRD型鼻侧CT降低幅度明显变缓(P=0.195)。结论 SRD型黄斑水肿患者CT在中心凹下及周边部均显著增厚,CT与DME病变程度之间有一定相关性。 相似文献
3.
Ahmed M. Abu El-Asrar Ajmal Ahmad Eef Allegaert Mohammad Mairaj Siddiquei Priscilla W. Gikandi Gert De Hertogh 《Ocular immunology and inflammation》2020,28(4):575-588
ABSTRACT
Purpose
To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR). 相似文献4.
Diabetic macular ischaemia (DMI) is traditionally defined and graded based on the angiographic evidence of an enlarged and irregular foveal avascular zone. However, these anatomical changes are not surrogate markers for visual impairment. We postulate that there are vascular phenotypes of DMI based on the relative perfusion deficits of various retinal capillary plexuses and choriocapillaris. This review highlights several mechanistic pathways, including the role of hypoxia and the complex relation between neurons, glia, and microvasculature. The current animal models are reviewed, with shortcomings noted. Therefore, utilising the advancing technology of optical coherence tomography angiography (OCTA) to identify the reversible DMI phenotypes may be the key to successful therapeutic interventions for DMI. However, there is a need to standardise the nomenclature of OCTA perfusion status. Visual acuity is not an ideal endpoint for DMI clinical trials. New trial endpoints that represent disease progression need to be developed before irreversible vision loss in patients with DMI. Natural history studies are required to determine the course of each vascular and neuronal parameter to define the DMI phenotypes. These DMI phenotypes may also partly explain the development and recurrence of diabetic macular oedema. It is also currently unclear where and how DMI fits into the diabetic retinopathy severity scales, further highlighting the need to better define the progression of diabetic retinopathy and DMI based on both multimodal imaging and visual function. Finally, we discuss a complete set of proposed therapeutic pathways for DMI, including cell-based therapies that may provide restorative potential. 相似文献
5.
目的:分析糖尿病视网膜病变合并黄斑水肿联合采用激光与复方血栓通胶囊治疗的临床疗效。方法:选取我院2017年1月—2019年1月收治的200例糖尿病视网膜病变合并黄斑水肿患者为研究对象,随机分为两组。对照组单独行激光治疗,观察组于对照组基础上联合复方血栓通胶囊治疗,对比两组临床疗效、治疗前后IL-6(白介素-6)、VEGF(血管内皮生长因子)、NOS(血清一氧化氮合成酶)水平变化情况。结果:对照组总有效率(68.00%,68/100)较观察组总有效率(98.00%,98/100)更高(P<0.05);与对照组对比,观察组治疗后NOS水平更高,IL-6、VEGF水平更低(P<0.05)。结论:糖尿病视网膜病变合并黄斑水肿联合采用激光与复方血栓通胶囊治疗的临床疗效显著,值得推广。 相似文献
6.
7.
Basic fibroblast growth factor mRNA, bFGF peptide and FGF receptor in epiretinal membranes of intraocular proliferative disorders (PVR and PDR) 总被引:3,自引:0,他引:3
Arno Hueber Peter Wiedemann Peter Esser Klaus Heimann 《International ophthalmology》1997,20(6):345-350
Basic fibroblast growth factor (bFGF) has been shown to be involved in epiretinal membrane formation in proliferative vitreoretinal disorders. However, up to now, little knowledge exists, as to the actual cellular source of this potent mitogen.We examined 20 epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) (n = 12) and proliferative vitreoretinopathy (PVR) (n = 8) for the presence of bFGF peptide, fibroblast growth factor receptor-1 (FGFR-1) and bFGF messenger ribonucleic acid (mRNA).Using a specific antibody, we detected bFGF peptide in most (8/10) examined PDR membranes and in all (8/8) PVR membranes. Moreover, we found positive staining for the corresponding receptor.Local production of bFGF in epiretinal membranes was confirmed by nonisotopic in situ hybridisation for bFGF mRNA in some (4/7) examined PDR membranes and some (3/4) examined PVR membranes. All membranes which contained bFGF mRNA were also positive for bFGF peptide.In conclusion, bFGF is produced and stored in epiretinal membranes. Together with the corresponding receptor, bFGF may play a role in the auto- and paracrine control of the proliferative processes at the vitroretinal interface.Abbreviations aFGF
acidic fibroblast growth factor
- bFGF
basic fibroblast growth factor
- FGFR-1
fibroblast growth factor receptor-1
- mRNA
messenger ribonucleic acid 相似文献
8.
糖尿病大鼠视网膜血管内皮生长因子与一氧化氮的变化 总被引:4,自引:1,他引:3
目的:探讨糖尿病大鼠视网膜血管内皮生长因子(VEGF)与一氧化氮(NO)的变化及其在糖尿病视网膜病变(DR)发生发展过程中的作用。方法:选择健康成年SD大鼠,随机分成正常对照组,糖尿病1月(DM1),糖尿病3月(DM3)和糖尿病5月(DM5)组,一次性腹腔注射链佐菌素(STZ)诱发糖尿病模型,应用免疫组织化学方法观察各组视网膜组织VEGF的表达情况,并检测各组视网膜组织中一氧化氮合酶(NOS)活性和NO含量变化。结果:3个月时,糖尿病大鼠视网膜VEGF表达增强,NOS活性增强,NO含量增高,5个月时,糖尿病大鼠视网膜表达进一步增强,而NOS活性开始减弱,NO含量减少,结论:糖尿病大鼠视网膜VEGF的过度表达和NOS活性,NO含量的变化在DR的发生发展过程中起重要作用。 相似文献
9.
N Deb-Joardar N Germain G Thuret A -F Garcin P Manoli A Defreyn P Gain B Estour 《Diabetic medicine》2007,24(3):303-307
AIMS: Screening for diabetic retinopathy (DR) is highly inadequate in France because of insufficient infrastructure and increasing disease prevalence. We describe the results of the first systematic DR screening programme established in a university diabetes department. METHODS: In this cross-sectional study conducted over 1 year, consecutive adult patients underwent three-field retinal photography with the Topcon TRC NW6S digital fundus camera following pupillary dilatation with Tropicamide 1%. A questionnaire provided information on patients' systemic and ocular history. Glycated haemoglobin (HbA1c) was measured at the screening visit.Two ophthalmologists graded the retinal photographs in a masked fashion. RESULTS: Of 1157 patients attending the diabetes department, 1153 (99.7%)underwent photographic screening. Images were gradable in 96% patients.Diabetic retinopathy was detected in 522 (45%) patients and sight-threatening DR in 167 (14%). Of 704 (61%) patients previously believed to have no DR,254 (34%) screened positive. The presence of DR was associated with age,insulin use and non-Caucasian ethnicity in Type 2 patients, and with duration of diabetes and HbA1c in Type 1 and Type 2 patients. Associated ocular pathologies were diagnosed in 612 (53%) patients. CONCLUSIONS: Our photographic screening programme using pharmacological mydriasis provided a high screening coverage feasible in a hospital setting. We obtained information regarding prevalence and associated risk factors of DR inpatients attending a tertiary care centre. Screening was well accepted by patients and met with no protest from city ophthalmologists. It generated considerable interest among endocrinologists and feedback of results is expected to improve optimization of glycaemic control. 相似文献
10.
目的观察和营清热降糖法为主治疗糖尿病视网膜病变的临床疗效。方法40例患者按中医辨证分为阴虚燥热证和气阴两虚、脉络瘀滞证,分别以和营清热、活血降糖及和营活血、利水降糖法治疗,治疗时间平均(5±1.2)月。结果总有效率分别为81.58%和73.33%,阴虚燥热证疗效优于气阴两虚、脉络瘀滞证。结论中医和营降糖法治疗糖尿病视网膜病变有较好疗效。 相似文献