Effects of cardiac contractility modulation on ventricular electrical remodeling in rabbits with chronic heart failure

AIM: To investigate the effects of cardiac contractility modulation (CCM) on ventricular electrical remodeling in a rabbit model of chronic heart failure. METHODS: The rabbits were divided into sham group, heart failure(HF) group and HF+ CCM group. The rabbit model of chronic heart failure was established by ligating the ascending aortic root. Then electrical stimulations during the absolute refractory period were delivered lasting 6 h everyday for 4 weeks in rabbits of HF+ CCM group. The QTc and ventricular effective refrective period (VERP) were recorded. The protein and mRNA levels of Kv1.4, Kv4.3 and connexin 43 (Cx43) were determined by Western blot and RT-qPCR. RESULTS: Compared with sham group, QTc were significantly prolonged in HF rabbits at week 12 (P<0.05). CCM therapy shortened QTc of rabbits with heart failure at week 16 (P<0.05). Compared with sham group, VERP significantly increased in HF group and HF+ CCM group, while CCM therapy shortened VERP of rabbits with heart failure at week 16 (P<0.05). Compared with sham group, the mRNA and protein levels of Kv1.4, Kv4.3 and Cx43 were decreased in HF group and HF+ CCM group (P<0.05). However, CCM therapy restored the mRNA and protein levels of Kv1.4, Kv4.3 and Cx43 of rabbits with heart failure (P<0.05). CONCLUSION: CCM suppresses ventricular electrical remodeling in heart failure and the underlying mechanism may be associated with increasing Kv1.4, Kv4.3 and Cx43 expression.     

全液压山地手扶式苜蓿刈割压扁机设计与试验

为适应我国山坡、丘陵地带苜蓿收获特殊需求,提高苜蓿收获机械作业操作灵活性和安全性,提出了一款山地手扶式苜蓿刈割压扁机。该机采用全液压驱动,整机液压系统由行走驱动回路、工作装置升降控制回路及工作装置驱动回路3部分组成,可实现自走、工作装置升降和刈割压扁作业;工作装置升降机构采用平行四连杆机构,以保证工作装置升降过程中割刀刀盘倾角不变。同时,进行了样机试制与田间性能试验,试验表明:整机能够有效地实现苜蓿的刈割、压扁作业,爬坡度可达30%,行驶速度可达5km/h,能够实现单边制动转向及原地转向等功能,满足山坡、丘陵地带苜蓿收获的需求。     

中国棉花转基因研究与应用

近十年来 ,植物基因工程取得了辉煌的成就 ,尤其是许多大田作物 (如水稻、玉米、烟草、番茄等 )的转基因产品已进入商品化生产阶段。本文就中国棉花基因工程方面的研究作一简要综述 ,主要包括抗虫性改良、抗除草剂性状改良、抗病性改良、抗逆性改良和品质性状改良等方面     

Internet Telerobotics and Its Applications

According to a new trend of telerobot control, some key techniues are researched to solve the Internet telerobotics , such as distributed intelligent computation on the Internet, human-computer interface,and Internet-robot interface etc.The current development status of the Internet telerobotics is reviewed. Based on the new directions of the network software development, the authors discuss that the middleware technique CORBA plays an important role in solving the problems of the Internet telerobotics,and it is an effective way to use Java language to control the telerobot and improve its system performance. The application perspective of the Internet telerobotics is investigated.It is indicated that the development trend of the telerobot control is a human-centred collaboration mechanism of mutual reinforce and coordination in human-machine intelligent.     

珠海市板樟山森林公园休闲保健型森林营建的研究

森林的多目标利用是当前林业界努力探索的方向,其中以维护大众健康为主的利用价值可能最易受到重视,休闲保健型森林以供人们休闲游憩、强身健体为主要经营目的,其营建在中国刚刚起步,其类型,作用、地位、意义,营建项目,途径和措施,以及与国民健康的关系等诸多方面不为大多数人所了解,本文强调森林在现代人休闲活动中的重要性,归纳了休闲保健型森林对人们精神,身体、技能诸方面的功效,以及休闲保健型森林的3种服务模式,介绍了珠海市板樟山森林公园休闲保健型森林的营建,并提出进一步改造的途径和措施;（1）诱鸟森林的营建;诱鸟林的选址,诱鸟林的植物配置,诱鸟区的活动项目设置。（2）休闲保健型森林改造的途径与措施;（1）营建四季分明,山花烂漫的森林;（2）具有人体保健功能的树种改造;（3）推行森林浴活动;（4）林相的整理与维护;（5）在自然保护的同时兼顾景观维护;（6）推行解说服务。     

防霉增强型竹碎料混凝土模板的研制

本文针对竹碎料混凝土模板易霉变的缺陷，采用线性回归分析法探讨了板材防霉性能与其密度的关系，同时采用五种防霉剂对竹碎料进行降糖防霉处理试验。结果表明，板材密度与防霉性能呈显著线性正相关，自制NPFB防霉剂效果理想，压制的防霉竹碎料混凝土模板物理力学性能达到JG／T3026—1995建筑工业竹胶合板模板行业标准。     

第二代杉木林养分动态研究

根据连续定位观测所取得的数据,对4个小集水区第二代10年生杉木人工林生态系统中的养分循环进行了研究.结果表明.集水区由降水输入的N、P、K、Ca、Mg等营养元素总计为59.285kg/hm2a,径流输出为38.938kg/hm2a,净积累量为20.347kg/hm2a.与该林分7年生时相比,净积累量提高了7.2%,说明集水区第二代杉木林生态恢复处于进展的变化过程.     

生态园林绿地建设中应用树木与草坪效果对比分析

本文从树木与草坪在用水量、观赏时间、造价、管理成本和环保上的 5项指标进行对比 ,论述了风沙、干旱地区的绿地建设应该是树木为本 ,花草点缀 ,乔木为主 ,灌木为辅的原则。     

白玉兰离体培养和快速繁殖

试验建立了白玉兰离体繁殖体系。种子为外植体 ,初代培养基为 :B5 +BA0 .5mg/L +NAA0 .0 5mg/L + 30g/L糖 +琼脂 6g/L ,萌发率 85 %。继代培养基为 :B5 +BA1.5mg/L +NAA0 .15mg/L + 30g/glucose/sucrose + 6g/Lagar+Vco0 .5g/L ,月增殖率可达 5 .0± 0 .1。生根培养为 :1/2B5+NAA0 .5mg/L +AC1.0mg/L +VB2 0mg/L。以试管苗茎段、根段做外植体 ,培养基B5 +BA2mg/L+ 2 .4 -D0 .5mg/L +VC0 .5g/L ,可获得少量愈伤组织 ,继代存活率仅为 30 %。没有再分化成苗     

丽水市竹业科技支撑建设

丽水竹产业实现了快速发展,其中科技起到重要的支撑作用.该文根据丽水市竹业技术现状和发展趋势,通过对竹产业的技术需求分析,提出了丽水市竹业科技支撑的主要内容、重点、方向和建议.