全文获取类型
收费全文 | 6361篇 |
免费 | 634篇 |
国内免费 | 92篇 |
学科分类
医药卫生 | 7087篇 |
出版年
2024年 | 29篇 |
2023年 | 95篇 |
2022年 | 237篇 |
2021年 | 234篇 |
2020年 | 197篇 |
2019年 | 175篇 |
2018年 | 228篇 |
2017年 | 232篇 |
2016年 | 262篇 |
2015年 | 240篇 |
2014年 | 376篇 |
2013年 | 398篇 |
2012年 | 378篇 |
2011年 | 378篇 |
2010年 | 339篇 |
2009年 | 332篇 |
2008年 | 286篇 |
2007年 | 323篇 |
2006年 | 293篇 |
2005年 | 306篇 |
2004年 | 242篇 |
2003年 | 199篇 |
2002年 | 163篇 |
2001年 | 149篇 |
2000年 | 113篇 |
1999年 | 96篇 |
1998年 | 75篇 |
1997年 | 54篇 |
1996年 | 47篇 |
1995年 | 48篇 |
1994年 | 65篇 |
1993年 | 42篇 |
1992年 | 47篇 |
1991年 | 25篇 |
1990年 | 25篇 |
1989年 | 22篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 14篇 |
1985年 | 30篇 |
1984年 | 43篇 |
1983年 | 54篇 |
1982年 | 45篇 |
1981年 | 34篇 |
1980年 | 31篇 |
1979年 | 19篇 |
1978年 | 31篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有7087条查询结果,搜索用时 26 毫秒
1.
Ihsan A. Badr 《International ophthalmology》1993,17(3):155-160
The region is characterized by diversity in cultural, political, economic and health conditions. Blindness in the region varies from 6.4% to 0.2% with cataract ranking highly as an underlying cause. There is a need to develop national policies to deliver affordable, technically suitable, and cost effective management plans to reduce cataract. Economic, demographic, health, and manpower statistics are essential information to be considered in formulating such policies. 相似文献
2.
糖尿病患者超声乳化白内障吸除手术的临床观察 总被引:4,自引:0,他引:4
目的:探讨糖尿病患者进行超声乳化白内障吸除联合人工晶状体植入手术的临床效果。方法:50例(61只眼)糖尿病患者(设为A组)和同期163例(174只眼)血糖正常患者(设为B组)接受超声乳化白内障吸除联合人工晶状体植入手术。糖尿病患者手术前通过饮食疗法、口服药物或肌注胰岛素治疗,使空腹血糖降到 10mmol/L以下。术后随访 1~28个月(平均 8.6个月),复查视力、裂隙灯及眼底检查。结果:术后矫正视力≥0.5者,A组为77.1%;B组为80.5%。两组经统计学处理差异无显著性(P>0.05)。两组术中出现后囊破裂及术后发生角膜水肿和前房渗出等并发症的差异无显著性(P>0.05 )。结论:糖尿病患者进行超声乳化白内障吸除手术前只要有效控制血糖,其手术效果与对照组患者相同。但术后血糖的控制仍然十分重要。眼科学报2003;19:98-100。 相似文献
3.
应用激光干涉视力仪检测了23例(23只眼)膜性白内障Nd:YAG激光切开术前及术后的干涉视力,结果显示:术前与术后干涉视力之间的差异无显著性(P>0.05)。术前干涉视力与术后矫正视力呈正相关(P<0.05),提示半透明膜性白内障对激光干涉视力无显著影响.激光干涉视力是反映术后视力康复的可靠方法.但在具体分析时,应注意假阴性和假阳性的可能.65.2%的眼术后矫正视力高于术后干涉视力,反映了高度屈光不正的无晶体眼对激光干涉条纹在视网膜上的形成有一定的影响. 相似文献
4.
Smoking has recently been identified from epidemiological studies as a possible cause of cataract but the mechanism involved is not known. Therefore, our laboratory has initiated studies aimed at elucidating these mechanisms. Whole bovine lenses were cultured to examine possible effects of cigarette smoke on amino acid uptake and protein synthesis. Cigarette smoke, filtered to remove nicotine and tar which would not reach the eye in vivo, was bubbled through culture medium. Bovine lenses were incubated in this medium in the presence of [14C]-leucine for four days. A significant decrease in uptake of [14C]-leucine and a decrease in protein synthesis were found with smoke treated lenses. This is the first demonstration of an effect of cigarette smoke on the lens. Further work is needed to determine how this metabolic upset is mediated and how it could lead to cataract. 相似文献
5.
Anthony P Cullen Olanrewaju M Oriowo Anita C Voisin 《Clinical & experimental optometry》1997,80(3):80-86
Concern about short- and long-term ultraviolet radiation (particularly UVB) damage to the eye has led to increased research in this area. Numerous studies have confirmed the pathogenic enhancing roles of reflected ultraviolet (UV) and visible radiation in our environment. There is concern that conventional sunglasses do not protect the eye adequately from reflected rays (albedo), especially on the lateral aspect, from behind and from below. Using eye models and computer ray tracing methods, the pathways of oblique rays incident at the temporal peripheral cornea have been plotted by Maloof, Ho and Coroneo.1 These rays are refracted and focused and theoretically can result in up to 20 times the concentration of incident irradiance at the nasal anterior chamber angle and nasal equatorial cortex of the crystalline lens. The purpose of this study was to determine the limits of angular subtense of the incident peripheral light which is refracted in this manner in human subjects and to investigate the relation between corneal shape and certain ocular parameters to the limits. A statistically significant positive correlation was found between temporal entrance angle and anterior chamber depth (r = 0.70, P< 0.0006). The entrance angle ranged from 15 degrees to 30 degrees and was located 10 degrees to 45 degrees posterior to the coronal plane. Our results support Maloof and colleagues' predictions for the implication of focused peripheral UV and high intensity visible radiation in the pathogenesis of pterygium and cortical cataract and emphasise the need for lateral eye protection in conditions of high ultraviolet albedo. 相似文献
6.
7.
8.
9.
10.
目的通过化学方法制成动物核性白内障模型,探讨相对能量复合指数(RECP)与角膜内皮细胞活性的关系。方法将5种化学物质注入晶状体,以透过黑白条纹的清晰程度判断晶状体混浊程度并分级。然后将实验眼球分为6组(Ⅰ组为对照组;Ⅱ-Ⅵ为实验组),行标准超声乳化白内障摘除手术。手术后立即取下角膜,作锥蓝-茜素红联合染色标本和扫描电镜标本。结果晶状体内注入甲醛、冰醋酸、无水乙醇、丙酮和苯扎溴铵均能形成晶状体混浊,其中:冰醋酸致晶状体混浊能力最弱,无水乙醇、丙酮次之,甲醛、苯扎溴铵最强。当RECP≤90时,锥蓝-茜素红双重染色和扫描电镜均表明角膜内皮细胞活性好,其形态和细胞联接均无改变。当RECP=120时,角膜内皮细胞形态尚正常,但是细胞联结和胞膜部分破坏。当RECP=150时,角膜内皮细胞严重损伤。结论用化学方法制作核性白内障模型供过渡训练使用是可行的。当RECP超过某一数值(>90)时,即与角膜内皮细胞的活性成负相关。 相似文献