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   66446篇
  免费   6265篇
  国内免费   4452篇
耳鼻咽喉   590篇
儿科学   745篇
妇产科学   637篇
基础医学   6442篇
口腔科学   1355篇
临床医学   9048篇
内科学   8380篇
皮肤病学   709篇
神经病学   2765篇
特种医学   2082篇
外国民族医学   28篇
外科学   5635篇
综合类   14015篇
现状与发展   18篇
一般理论   10篇
预防医学   5655篇
眼科学   1489篇
药学   7789篇
  100篇
中国医学   4909篇
肿瘤学   4762篇
  2024年   308篇
  2023年   1080篇
  2022年   2976篇
  2021年   3829篇
  2020年   3021篇
  2019年   2149篇
  2018年   2202篇
  2017年   2301篇
  2016年   2025篇
  2015年   3176篇
  2014年   4076篇
  2013年   4089篇
  2012年   5663篇
  2011年   6098篇
  2010年   4442篇
  2009年   3632篇
  2008年   4013篇
  2007年   3822篇
  2006年   3559篇
  2005年   2956篇
  2004年   2024篇
  2003年   1813篇
  2002年   1588篇
  2001年   1127篇
  2000年   973篇
  1999年   887篇
  1998年   530篇
  1997年   536篇
  1996年   353篇
  1995年   348篇
  1994年   314篇
  1993年   183篇
  1992年   193篇
  1991年   162篇
  1990年   148篇
  1989年   89篇
  1988年   102篇
  1987年   107篇
  1986年   74篇
  1985年   67篇
  1984年   43篇
  1983年   24篇
  1982年   20篇
  1981年   22篇
  1980年   5篇
  1979年   11篇
  1976年   1篇
  1970年   1篇
  1964年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
目的 前房注射卡波姆建立大鼠高眼压模型,观察卡波姆升眼压效果及对大鼠眼前节和视网膜的影响。方法 随机选取30只SD大鼠,注射前3 d早晚测量基线眼压。右眼定为实验眼,左眼定为对照眼,右眼放出房水后将30 μL的5 g·L-1卡波姆混悬液注入前房,每日早10时、晚22时在大鼠清醒状态下测量眼压。每周进行双眼眼前节照相并对比。4周末处死26只大鼠(另4只持续观察眼压变化至注射后9周)并取双眼眼球行HE染色,观察实验眼与对照眼视网膜形态,对比视网膜厚度及房角形态。结果 注射前,实验眼白天和夜间眼压分别为(11.10±0.90)mmHg(1 kPa=7.5 mmHg)和(11.92±1.07)mmHg,对照眼分别为(11.22±1.07)mmHg和(11.76±1.08)mmHg;实验眼与对照眼相比,白天、夜间眼压差异均无统计学意义(均为 P>0.05);白天与夜间眼压相比,实验眼、对照眼差异均有统计学意义(均为P<0.05)。卡波姆在前房中呈现出弥散型和沉积型两种存在方式,弥散型和沉积型大鼠1周内眼压分别为(17.83±3.54)mmHg和(13.00±1.55)mmHg,两者相比差异具有统计学意义(P<0.05)。注射后第1天至第19天,实验眼与对照眼白天眼压相比差异均具有统计学意义(均为P<0.05);注射后第1天至第27天,实验眼与对照眼夜间眼压相比差异均具有统计学意义(均为P<0.05)。实验眼视网膜形态发生改变,注射后4周视网膜厚度为(254.70±21.80)μm,与对照眼的(346.73±24.63)μm相比,差异有统计学意义(P=0.00)。实验眼前房充满卡波姆及虹膜的混合成分,紧贴角膜内皮并延伸至房角,堵塞小梁网结构,正常虹膜形态消失;对照眼房角形态正常。结论 前房注射卡波姆建立大鼠高眼压模型,可维持高眼压4周以上,昼夜眼压差异较为明显,夜间眼压较白天更高,4周后视网膜出现高眼压损伤后的表现。  相似文献   
4.
Objective To observe the clinical characteristics and prognosis of patients with rapidly progressive glomerulonephritis (RPGN) caused by lupus nephritis, antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, or primary glomerulonephritis who were treated with peritoneal dialysis (PD) and then withdrew PD because of renal recovery. Methods Data of the above patients were retrospectively analyzed. The patients were diagnosed as RPGN and received PD therapy in Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University from February 2009 to August 2018. The patients were divided into early withdrawal group (PD time≤183 days, n=24) and late withdrawal group (PD time>183 day, n=24). The differences of clinical characteristics between the two groups were compared. The cumulative incidence of adverse events in both groups was analyzed using Kaplan-Meier curves. Cox proportional hazards model was used to analyze the risk factors influencing the prognosis of patients. Results Forty-eight RPGN patients were included. The median time of maintaining PD was 178(76, 378) days. Compared with the late withdrawal group, the patients in early withdrawal group had lower levels of urine volume, serum albumin and parathyroid hormone, and lower rates of gross hematuria and hypertension at the beginning of PD, and received higher rates of methylprednisolone impulse, combined immunosuppressive agents, and hemodialysis or continuous renal replacement therapy (all P<0.05). At the time of PD withdrawal, the levels of serum creatinine, serum calcium, serum albumin and parathyroid hormone in the early withdrawal group were significantly lower than those in the late withdrawal group (all P<0.05). The Kaplan-Meier curves showed that there was no significant difference in the cumulative survival of patients in both groups (log-rank test χ2=3.485, P=0.062). Cox regression analysis revealed serum creatinine≥209 μmol/L at the time of PD withdrawal was an independent risk factor for poor prognosis (HR=5.253,95%CI 1.757-15.702, P=0.003). Conclusions PD can be used for RPGN patients caused by lupus nephritis, ANCA-associated vasculitis and primary nephritis. Serum creatinine≥209 μmol/L at the time of PD withdrawal is an independent risk factor for poor prognosis.  相似文献   
5.
瘙痒是皮肤科的一种常见症状,是多因素相互作用的结果,其发生受到中枢和外周机制的双重调控,但具体发生机制尚不十分清楚。近年来随着研究的不断深入,多种物质如组胺、乙酰胆碱、5-羟色胺、蛋白酶和蛋白酶相关受体、细胞因子、阿片样肽等介质在瘙痒产生过程中起重要作用,这些介质通过刺激C类神经纤维或直接与皮肤感觉神经纤维受体相结合来介导瘙痒。本文就将皮肤瘙痒的神经传导及传导介质作一综述。  相似文献   
6.
7.
8.
9.
Background: Previous genome-wide association study (GWAS) has revealed the association between MYP10 at 8p23 and MYP15 at 10q21.1 and high myopia (HM) in a French population. This study is managed to discover the connection between some single nucleotide polymorphism (located at MYP10 and MYP15) and Han Chinese HM.

Methods and Results: This case-control association study contained 1673 samples, including 869 ophthalmic patients and 804 controls. Twelve tag SNPs have been selected from the MYP10 and MYP15 loci and genotyped by SNaPshot method. Among 12 SNPs, rs4840437 and rs6989782 in TNKS gene were found significant association with HM. Carriers of rs4840437G allele and rs4840437GG genotype created a low risk of high myopia (P = .036, OR = 0.81, 95%CI = 0.71–0.93; P = .016, OR = 0.73, 95%CI = 0.56–0.96; respectively). Carriers of rs6989782T allele and rs6989782TT+CT genotype also had a decreased risk of high myopia (P = .048, OR = 0.82, 95%CI = 0.71–0.94; P = .006, OR = 0.74, 95%CI = 0.59–0.92; respectively). Other 10 SNPs displaced nonsignificant association with HM. Additionally, the risk haplotype AC and the protective haplotype GT, generated by two SNPs in TNKS, were considerably more likely to be association with HM (for AC, P = .002 and OR = 1.26; for GT, P = .027 and OR = 0.84).

Conclusions: Our results demonstrated that some heritable variants in the TNKS gene are associated with HM in the Han population. The possible functions of TNKS in the development and pathogenesis of hereditary high myopia still require further researches to identify.  相似文献   

10.
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