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   4491篇
  免费   519篇
  国内免费   67篇
耳鼻咽喉   61篇
儿科学   30篇
妇产科学   6篇
基础医学   242篇
口腔科学   26篇
临床医学   162篇
内科学   104篇
皮肤病学   39篇
神经病学   193篇
特种医学   55篇
外科学   61篇
综合类   287篇
预防医学   65篇
眼科学   3235篇
药学   361篇
中国医学   91篇
肿瘤学   59篇
  2024年   22篇
  2023年   89篇
  2022年   106篇
  2021年   196篇
  2020年   200篇
  2019年   166篇
  2018年   193篇
  2017年   199篇
  2016年   205篇
  2015年   184篇
  2014年   214篇
  2013年   478篇
  2012年   181篇
  2011年   264篇
  2010年   213篇
  2009年   201篇
  2008年   195篇
  2007年   194篇
  2006年   177篇
  2005年   151篇
  2004年   146篇
  2003年   107篇
  2002年   90篇
  2001年   100篇
  2000年   65篇
  1999年   54篇
  1998年   53篇
  1997年   53篇
  1996年   33篇
  1995年   43篇
  1994年   24篇
  1993年   29篇
  1992年   23篇
  1991年   25篇
  1990年   27篇
  1989年   23篇
  1988年   24篇
  1987年   15篇
  1986年   22篇
  1985年   52篇
  1984年   52篇
  1983年   40篇
  1982年   40篇
  1981年   32篇
  1980年   41篇
  1979年   15篇
  1978年   12篇
  1977年   3篇
  1976年   6篇
排序方式: 共有5077条查询结果,搜索用时 343 毫秒
51.
弱视遮盖治疗对屈光度和立体视的影响   总被引:1,自引:0,他引:1  
目的 :研究主眼遮盖对弱视儿童屈光度和立体视的影响。方法 :动态分析经主眼遮盖法基本治愈的弱视 6 2例治疗前后双眼屈光度和立体视的变化。结果 :6 2例患儿平均遮盖主眼 2 5± 1 7年后 ,视力 >0 8,基本治愈 ;治疗后双眼球镜度均较治疗前下降 ,未遮盖眼下降更明显 ;双眼柱镜度无显著变化 ,立体视功能改善与治疗前差异有显著性。结论 :对弱视儿童主眼进行遮盖 ,未加速被遮盖眼的近视化 ,适当的遮盖治疗不会对立体视发育造成显著影响。  相似文献   
52.
目的 观察川芎嗪对慢性眼高压下视网膜神经细胞损伤的保护作用 .方法 用 2 0 g· L- 1 甲基纤维素前房注射法建立兔慢性眼高压模型 .4组分别给予生理盐水、川芎嗪注射液 10 mg· kg- 1 ,2 .5 g· L- 1 噻吗心安眼液和联合应用川芎嗪与噻吗心安 ,连续用药 4wk.于 2 8d取眼球作光镜、电镜检查和光镜下细胞计数 .结果 生理盐水组模型眼节细胞数为 (7.83± 1.34 )个 /10格 ,双极细胞数为 (10 .6 6± 1.6 3)个 /格 ;川芎嗪组模型眼节细胞数为 (9.5 0± 3.87)个 /10格 ,双极细胞数为 (12 .5 0± 2 .73)个 /格 ;生理盐水组模型眼和川芎嗪组模型眼节细胞 (P<0 .0 5 )与双极细胞 (P<0 .0 5 )比较 ,有显著性差异 .生理盐水组模型眼节细胞变性、坏死 ,锥、杆细胞外节紊乱 ,色素上皮不完整 ,川芎嗪组变化比生理盐水组轻 ,联合用药组变化最小 .结论 川芎嗪对慢性眼高压下视网膜神经节细胞和双极细胞具有保护作用 .  相似文献   
53.
新鲜羊膜移植治疗眼表疾病的临床评价   总被引:3,自引:0,他引:3  
目的 评价新鲜人羊膜在眼表重建术手术中的临床价值。方法 用新鲜羊膜移植,治疗陈旧性睑球粘连、结膜囊缺失,复发性翼状胬肉、蚕蚀性角膜溃疡、热烧伤后角膜和结膜溶解等眼表疾病的连续病例19例(21只眼)。结果 19例患者的羊膜移植手术均为一次成功。平均随访12.5个月,羊膜移植片未见免疫排斥反应或溶解吸收。手术后,患者的睑球粘连松解,结膜囊形成,蚕蚀性角膜溃疡和复发性翼状胬肉在随访期间未见复发,角膜和结  相似文献   
54.
The 4th nationwide epidemiological survey on Behçet disease (BD), which included all patients with BD at 1,200 hospitals selected at random from 10,081 hospitals in Japan, was carried out by the BD Research Committee of the Ministry of Health and Welfare in 1991 to examine the epidemiological features of BD in Japan by comparing with previous surveys. 3,938 patients from these hospitals were examined by the Japanese diagnostic criteria of BD (JCBD) revised in 1987 and the International criteria for classification of BD (ICBD). Among these 3,938 patients, 622 patients were only suspected of having BD or clinical signs of the disease were unknown, and most of these patients were incompatible with the ICBD. So these patients were excluded from the study of epidemiological features. The average patients age has risen 7–8 years over the last 20 years and the average age of onset in both sexes increased by about 3 years from 1972 to 1991. While a decrease in the sex ratio was seen in the complete-type and the incomplete-type BD without ocular symptoms, a sustained high sex ratio was shown in incomplete-type BD with ocular symptoms. The positive rate of HLA-B51 antigen was 54.9% (men: 56.9%, women: 52.2%) significantly higher than die 15–16% in healthy subjects but it might have been gradually decreasing. Also the clinical course of BD has become too mild for prognosis. According to diese epidemiological features of BD, the clinical manifestation of BD in Japan might have become the Western type of BD.  相似文献   
55.
Hongshan  Chen  Chenjin  Jin 《眼科学报》1999,15(1):61-64
Purpose: To investigate the compliance of the patients with ocular fundus diseases with recommendation for follow-up examination after laser treatment, and the underlying reasons for non-compliance.Methods: 53 patients with ocular fundus disease were asked to fill in a questionnaire which includes the socio-demographic characteristics, fear of the fundus disease, conception of the laser treatment and the motivation for staying healthy. Variables were compared for the compliers group and the non-compliers group by chi-square test. Result; Of the 53 subjects, 35 were classified as non-compliers and 18 were classified as compliers. There was no statistically significant difference between the two groups on all selected socio-demographic factors, conception of the laser treatment and the motivation for staying healthy. Significant difference was found between the two groups on two of those items concerning the fear of the diseases (P<0. 05). About half of the participants showed the lack of knowledge about  相似文献   
56.
57.
Background: Von Hippel–Lindau disease (VHL) is a rare autosomal dominant inherited disorder characterized by highly vascularized tumors in various organs. The abundant presence of endothelial cells in VHL tumors strongly suggest a role of the VHL tumor suppressor gene in the regulation of angiogenesis. Recently, in vitro studies have shown that the VHL tumor suppressor gene regulates the expression of vascular endothelial growth factor (VEGF). We investigated whether VHL patiens have increased levels of VEGF in their body fluids.Patients and methods: The concentration of VEGF was measured in fluid of the anterior chamber of the eye, serum, urine, and fluid from renal cysts of VHL patients and unaffected individuals by ELISA. In addition, levels of basic fibroblast growth factor (bFGF), interleukin-8 (IL-8) and endothelin-1 (ET-1) were measured in urine and serum of VHL patients and control subjects.Results: In 80% of the VHL patients VEGF was detectable in aqueous fluid of the anterior chamber of their eyes. A strong positive correlation (r = 0.90) was found between the age of VHL patients and ocular VEGF concentrations. At comparable age, VEGF levels in ocular fluid of VHL patients were significantly higher (P < 0.001) than in unaffected subjects. No correlation was found between VEGF concentration and the presence of retinal angiomas. A 10 and 16 fold increase of VEGF concentration was seen in fluid from two independent VHL-related cysts as compared with VEGF serum levels of the same patient. The mean concentration of VEGF in serum of VHL patients (n = 15) (319 ± 84 pg/ml) was higher than in matched controls (238 ± 68 pg/ml; P = NS). The mean concentration of VEGF in urine of VHL patients (128 ± 36 pg/ml) was lower than in matched controls (183 ± 25 pg/ml; P = NS). Concentrations of VEGF did not correlate with the presence of VHL-related tumors. No differences were observed between concentrations of bFGF, IL-8 and ET-1 in serum and urine of VHL patients and matched controls.Conclusions: These findings support a role for the VHL tumor suppressor gene in the in vivo regulation of VEGF.  相似文献   
58.
目的:探讨针剌对家兔实验性高眼压的影响。方法:应用2%α糜蛋白酶注入家兔眼后房,形成实验性高眼压症。将已形成高眼压的25只家兔眼分为针剌组(10只眼)、西药组(10只眼)和对照组(5只眼)。各组在针剌和药物治疗前后均测量眼压。结果:治疗前针剌组、西药组和对照组的眼压分别为562kPa,629kPa和546kPa,3组之间无显著性差异(P>005)。针剌组针剌后在1~3小时内与对照组相比眼压均有明显降低(P<0001);西物组在药物治疗后1~3小时内与对照组相比眼压也有降低(P<005)。结论:针剌具有降低家兔实验性高眼压的作用。  相似文献   
59.
目的观察人体于不同的头位倾斜条件下诱发的OCR反应特征,为建立其检测方法和实际应用提供依据.方法受试对象为地面人员22名和飞行人员11名,端坐于装有特制头托的座椅上,通过头位在冠状面内分别处于左右各倾斜30°、50°、70°的位置诱发静态OCR反应.采用红外视频眼动记录方法分别随机测定从头直位到左右各30°、50°、70°的眼动视频信号.最后以动头前即刻的眼球位置为零位,以眼球虹膜纹理为标志,对各时刻虹膜纹理与初始状态虹膜纹理进行互相关分析,找出相关度最大的一点为各时刻眼球位置,测量该时刻眼球与初始眼球位置的角度即为眼球扭转角度.结果头位倾斜引起的典型OCR反应曲线特征是,头位倾斜动作开始,首先引起一个幅度较大的与头动方向相反的眼球反方向旋转,随之,眼球反转角度逐渐减小,在头位倾斜到固定角度后,眼球反转角度在一定范围内波动或不变,未发现头位向同一方向倾斜不同角度引起的OCR有显著差异.飞行员与正常地面人群OCR反应未见显著差别.结论静态头位倾斜可以诱发出OCR反应,可用来评价耳石器功能.  相似文献   
60.
目的:观察唯地息眼凝胶剂对兔芥子气角膜上皮损伤的治疗作用。方法:新西兰白兔8只,用200μL/L液态芥子气致伤双眼角膜5min,左眼为治疗组,用唯地息眼凝胶剂点眼,4次/d,右眼为对照组,用2.5g/L氯霉素眼液滴眼,4次/d,分别于染毒后2,8,16,24,36,48和72h对角膜荧光素着色区拍照,计算其上皮愈合速率和上皮破损率。结果:治疗组和对照组的角膜上皮愈合速率分别为(1.15±0.19)mm2/h和(1.03±0.12)mm2/h,两者有显著差异(P<0.05),角膜上皮破损率分别为44.4%和54.2%,两者差异显著(P<0.05)。结论:唯地息眼凝胶剂能促进芥子气染毒引起的兔眼角膜损伤的上皮愈合,也能减少角膜上皮反复破损。  相似文献   
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