全文获取类型
收费全文 | 1046篇 |
免费 | 38篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 166篇 |
妇产科学 | 23篇 |
基础医学 | 34篇 |
临床医学 | 72篇 |
内科学 | 176篇 |
神经病学 | 18篇 |
特种医学 | 6篇 |
外科学 | 16篇 |
综合类 | 123篇 |
预防医学 | 49篇 |
眼科学 | 359篇 |
药学 | 42篇 |
中国医学 | 20篇 |
肿瘤学 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 24篇 |
2022年 | 38篇 |
2021年 | 38篇 |
2020年 | 46篇 |
2019年 | 44篇 |
2018年 | 53篇 |
2017年 | 22篇 |
2016年 | 26篇 |
2015年 | 36篇 |
2014年 | 92篇 |
2013年 | 71篇 |
2012年 | 81篇 |
2011年 | 77篇 |
2010年 | 64篇 |
2009年 | 51篇 |
2008年 | 67篇 |
2007年 | 35篇 |
2006年 | 48篇 |
2005年 | 26篇 |
2004年 | 17篇 |
2003年 | 21篇 |
2002年 | 7篇 |
2001年 | 14篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有1114条查询结果,搜索用时 15 毫秒
21.
Hypertension is an established risk factor for retinopathy. Whether it is an independent risk factor or acts only by association with nephropathy is not known. Therefore, we studied 273 Type 1 diabetic patients. They were divided into four groups. Group 1 (n = 55) were normotensive and normoalbuminuric, group 2 (n = 51) had hypertension but were normoalbuminuric, group 3 (n = 33) had nephropathy but were normotensive, and group 4 (n = 134) had nephropathy and hypertension. Hypertensive patients with normoalbuminuria (blood pressure 146 +/- 19 (+/-SD)/87 +/- 12 mmHg) had the same prevalence of retinopathy as normoalbuminuric normotensive patients (123 +/- 12/75 +/- 5 mmHg). Hypertensive nephropathic patients (blood pressure 147 +/- 18/87 +/- 8 mmHg) had more retinopathy than hypertensive normoalbuminuric patients despite similar blood pressure (normal retina/advanced retinopathy: 3%/73% vs 46%/17%, p less than 0.001). Nephropathic normotensive patients had worse retinal changes than hypertensive normoalbuminuric patients (19%/49%, p less than 0.001) but fewer than the nephropathic hypertensive patients p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
22.
23.
Summary In 231 subjects with Type 1 diabetes mellitus aged 17.6 ± 4.0 years, with a diabetes duration of 8.5 ± 4.9 years at the end
of the study, the prevalence and the development of retinopathy during a period of 5 years were studied. All patients were
examined between one and six times both by ophthalmoscopy and fluorescein angiography. A total of 626 fluorescein angiographies
were evaluated. By the end of the study, 109 out of 231 patients (47%) had developed retinal changes, half of which were classified
as minimal (<5 microaneurysms). Thirty-eight patients (35% of those affected) had background (n = 28) or proliferative (n = 10) retinopathy. In subjects less than 15 years of age and diabetic for less than 5 years, retinal lesions were rare. With
increasing age and duration of diabetes, both the prevalence and severity of retinal changes increased markedly. Life-table
analysis was used to calculate the median individual risk for the development of early retinal changes, which was 9.1 years
of diabetes duration. This risk differed in sub-groups with different ages at onset of diabetes, i. e. 12.1, 8.9 and 6.6 years
(p < 0.0001), with diabetes starting below 4, between 5 and 9, and after 10 years of age respectively. After 18 years of diabetes,
every patient demonstrated at least incipient structural changes. Fluorescein angiography allowed the detection of retinopathy,
on average, four years earlier than with ophthalmoscopy. The median interval between the ‘onset’ of retinopathy, as indicated
by a few microaneurysms, and background retinopathy was 5 years. 相似文献
24.
Diabetes mellitus (DM) is a systemic, chronic metabolic disease that is related to heredity and autoimmunity and is often accompanied by complications of retinopathy. However, the causative mechanism involved in the pathological process remains unclear. In this research, treatment with fosinopril or LY2109761 was found to be responsible for the improvement of the pathological processes, serum biochemical indexes and retinopathy in rats with streptozotocin-induced diabetes. In addition, the upregulation of angiotensin-converting enzyme (ACE) in the serum and the increased expression of TGF-β1 in the pathological outer nuclear layer (ONL) and inner nuclear layer (INL) of the retina were also reduced. In vitro experiments demonstrated that ACE enhanced cell damage and TGF-β1/Smad signaling pathway activation in retinal capillary endothelial cells (RCECs) under high glucose conditions. In addition, the activity of ACE was also considered to be related to the increasing levels of activated TGF-β1 in both rat retinal Müller cells (RMCs) and RCECs, but ACE activity had no effect on the high glucose-mediated upregulation of total TGF-β1 in RMCs. Coculture experiments with RCECs and RMCs showed that the barrier that was established under normal conditions was significantly impaired when exposed to high glucose combined with ACE, and damage of barrier can be prevented by adding fosinopril or LY2109761. Finally, a similar auxiliary effect of ACE was also observed in the activated TGF-β1-mediated barrier damage in blood-retinal barrier model in vitro. In summary, ACE-mediated TGF-β1/Smad signaling pathway activation was found to be involved in the destruction of the blood-retina barrier during diabetic retinopathy in a model of streptozotocin-induced diabetes, and these data may provide evidence to guide the treatment of the complications of diabetes mellitus. 相似文献
25.
目的分析内皮祖细胞(EPCs)与极低出生体重早产儿发生支气管肺发育不良(BPD)、早产儿视网膜病(ROP)和脑室内出血(IVH)并发症的相关性。方法选取于复旦大学附属儿科医院NICU住院的胎龄〈32周、出生体重〈1500g的早产儿,分别于出生时、生后7、14、21和28d及纠正胎龄36周时收集外周血,流式细胞仪检测EPCs水平,酶联免疫法检测血管内皮生长因子(VEGF)、基质细胞衍生因子等水平。结果68例极低出生体重早产儿纳入分析,其中对照组30例,BPD组20例,ROP组10例,IVH组8例。BPD组与对照组出生时EPCs水平差异无统计学意义,生后7d时点EPCs水平较对照组明显降低,CD34+KDR+:(0.019±0.009)%伽(0.026±0.012)%,P〈0.05;KDR+CDl33+:(0.004±D.002)%傩(0.008±0.004)%,P〈0.01;CD34+KDR+CDl33+:(0.005±0.002)%船(0.008±0.004)%,P〈0.05。从出生时至生后21d,BPD组血浆VEGF水平均明显低于对照组。ROP组出生时至生后28d的EPCs水平与对照组差异无统计学意义,纠正胎龄36周时KDR+CDl33+和CD34+KDR+CDl33+EPCs与对照组相比略有升高趋势。与对照组相比,IVH组生后不同时点的EPCs水平差异均无统计学意义。结论生后早期的EPCs和VEGF水平降低可能参与了早产儿BPD的发生,但其具体机制仍需进一步研究。 相似文献
26.
目的:探讨对糖尿病并发视网膜病变患者实施持续健康教育的效果。方法将280例糖尿病并发视网膜病变患者,按随机数字表法分为观察组和对照组,每组140例。两组患者均给予常规的基础治疗和护理方法进行治疗,观察组在常规治疗的基础上应用持续健康教育。依据自我护理能力测定表( ESCA)、自制自我管理能力调查表、视功能损害眼病患者生活质量量表对糖尿病并发视网膜病变患者的健康教育结果、自我管理能力和生活质量的水平进行评价。采用SPSS 18.0统计软件进行数据分析。结果实施健康教育前两组患者ESCA 4个维度评分及总分、生活质量评分差异均无统计学意义( P>0.05);实施健康教育后,观察组患者ESCA总分为(122.1±11.7)分,生活质量总分为(47.1±4.2)分,均高于对照组(106.0±10.3),(34.6±4.1)分,差异有统计学意义(t值分别为3.692,8.926;P<0.05), ESCA 4个维度评分两组比较差异均有统计学意义(P<0.05);观察组患者在对疾病的自我管理能力优于对照组,差异有统计学意义(P<0.01)。结论持续健康教育能够提升糖尿病并发视网膜病变患者健康教育的效果,提高患者自我管理能力,改善其生活质量。 相似文献
27.
Pathologic angiogenesis induced by hypoxia is a hallmark of ischemic retinopathy including diabetic retinopathy and retinopathy of prematurity. These 2 diseases affect substantial number of working population and preterm babies, respectively, resulting in visual deterioration. It is essential for novel therapeutics for ischemic retinopathy to demonstrate the potency in reducing pathologic angiogenesis and the safety without definite toxicity on the retina and the whole body. In this review, we suggest a novel platform of integrative studies from in vitro to in vivo experiments on angiogenesis and toxicity with the aim of accelerating and facilitating the development of novel therapeutic agents for ischemic retinopathy. Robust in vitro and in vivo studies with bridging microfluidic and ex vivo systems help researchers to evaluate the efficacy and anticipate the toxicity of candidate drugs. We hope that novel therapeutic approach based on this platform will be developed in near future and reduce the incidence of vision loss from ischemic retinopathy. 相似文献
28.
Yoon Jeon Kim June-Gone Kim Joo Yong Lee Kyoung Sub Lee Soo Geun Joe Joong-Yeol Park Min-Seon Kim Young Hee Yoon 《Journal of Korean medical science》2014,29(12):1699-1705
The aim of this study was to evaluate the incidence of and risk factors for the development of diabetic retinopathy (DR) and progression to proliferative DR (PDR) in Korean patients. Patients diagnosed with type 2 diabetes and followed for more than 5 years at a university-based clinic since 2000 were consecutively enrolled in this retrospective cohort study. Based on the DR classification at the initial and final visits, the incidence and progression of DR was determined and patient characteristics were compared according to DR progression. Hazard ratios of each putative risk factor for DR progression were calculated with a multivariate Cox proportional hazard model. Rate of DR development and progression to PDR were 32.1/1,000 and 26.2/1,000 person-years, respectively. A longer duration of diabetes and higher mean HbA1c level were significant risk factors for the development of DR. Regarding progression to PDR, higher mean HbA1c level, higher standard deviation of HbA1c, and higher urine albumin-to-creatinine ratio were significant risk factors. The rates of development of DR and progression to PDR in Koreans with type 2 diabetes are lower than those reported over the last decade. An inadequate blood glycemic control is the common risk factor for development and progression of DR.
Graphical Abstract
相似文献29.
目的 探究老年糖尿病视网膜病变(DR)患者血清中miR-29b和miR-126水平及相关性研究。方法 选取2017年5月-2019年11月来台州市立医院接受治疗的126例老年DR患者作为研究对象,其中单纯2型糖尿病(DM)组42例,非增殖性糖尿病视网膜病变(NPDR)组40例,增殖性糖尿病视网膜病变(PDR)组44例;另选取40例老年体检者作为对照组。采用实时荧光定量PCR方法检测血清中miR-29b和miR-126水平。比较各组间血清miR-29b、miR-126,血压、血糖及血脂等指标差异,将影响糖尿病患者视网膜病变的指标进行单因素分析,同时应用多因素Logistic逐步回归分析探讨糖尿病视网膜病变的危险因素。结果 四组血清miR-29b和miR-126水平比较差异均有统计学意义(P<0.05),其中PDR组血清miR-29b水平明显高于对照组、DM组及NPDR组,且miR-126水平明显低于对照组、DM组及NPDR组;NPDR组血清miR-29b明显高于DM组和对照组,且miR-126明显低于DM组和对照组(P<0.05);NPDR组及PDR组SBP、DBP明显高于对照组,NPDR组、PDR组及DM组FBG、2hPG、HbA1c、TG、TC、HDL-C水平明显高于对照组,PDR组FBG、2hPG、HbA1c、TG水平明显高于DM组(P<0.05)。单因素分析显示,年龄、血清miR-29b、miR-126、HbA1c、FBG等因素具有统计学意义(P<0.05)。多因素Logistic逐步回归分析,结果显示患者年龄<75岁、血清miR-126<2.43ng/ul为老年糖尿病患者视网膜病变的保护因素,血清miR-29b≥8.38ng/ul、HbA1c≥6.00%、FBG≥8.15mmol/L为老年糖尿病患者视网膜病变的危险因素。结论 老年DR患者血清miR-29b水平升高,而血清miR-126水平降低,二者有望成为老年糖尿病视网膜病变的有效生物标志物。 相似文献
30.
Marlene Coelho da Costa Gabriela Unchalo Eckert Bárbara Gastal Borges Fortes Jo?o Borges Fortes Filho Rita C. Silveira Renato S Procianoy 《Clinics (S?o Paulo, Brazil)》2013,68(2):199-203