农业科技报道应注意典型引路和问题挖掘

通过总结笔者多年来在农业科技报道中的一些实际做法,探讨了媒体在农业科技报道中如何取得最佳的宣传效果,针对以往农业科技报道浮于表层,向深度和广度报道开掘不够的问题,提出两个解决方案:一是在农业科技报道中,记者要注意发挥典型引路的作用,通过典型报道吸引农民使用农业科技成果;二是记者在科技报道中要善于发现农业科技推广中所遇到的问题,通过公开报道引起有关部门的重视,以便更好地进行推广。     

玉米叶片定向生长栽培研究

玉米叶片生长习性为互生,叶片生长方向受数量性状遗传和种胚发育特性双重因素控制。通过人为干预种胚在土壤中的空间位置,可实现玉米叶片的定向生长。试验通过不同种植密度,不同种植行向,不同品种类型对玉米叶片定向生长的影响进行研究。结果表明,人为控制种子种胚的播种方位,可有效提高叶片生长的定向率,进而合理增加种植密度至13.5万株hm2,提高产量15%左右。种植行向对定向率无影响,紧凑型品种定向率高于半紧凑型和平展型。      

Recent advance in cardiac ion channel remodeling in diabetes

Occurrence of lethal cardiac arrhythmia, which is associated with prolongation of the QT interval in electrocardiogram(ECG), is related to increased mortality in the patients with diabetes mellitus (DM). Increased QT interval reflects the prolonged cardiac action potential duration (APD). APD abnormality is based on by cardiac ion channel remodeling induced by DM-related pathological changes. As DM is becoming an important risk factor for atrial fibrillation, the most clinically common arrhythmia, this review mainly summarizes the alterations of ion channel currents and relevant protein expression in diabetic ventricular myocytes to explore the underlying mechanisms of arrhythmia, and also discusses some research achievements from investigating the atrial myocytes in DM.     

Effect of captopril on prolongation of action potential duration and reduction Ik in ischemia pig ventricular myocytes

AIM: To evaluate the effect of captopril on action potential duration and outward delayed rectification potassium current (Ik). METHODS: Action potentials were recorded using a conventional glass microelectrode filled with 3 mol/L KCl solution. Membrane patch clamp whole cell recording technique was used to investigate the Ik current maximum in the holding potential -50 mV, lasting time 100 ms, command potential +40 mV. RESULTS: The action potential duration of 30%, 50% repolarization (APD30, APD50) and ERP were significantly prolonged, but APD90 wasn't prolonged significantly when captopril group compared with ischemic group. The amplitude of Ik increased significantly in ischemic group, but significantly decreased in captopril group and in captopril+ischemic group. The shapes of current-voltage relationship were unchanged among groups, but significantly upward in ischemic group and downward in captopril and captopril+ischemic group. CONCLUSION: Captopril exerts electrophysiologic action due to decreasing delay outward rectification potassium current and prolonging action potential duration of APD30, APD50 and ERP.     

应用噬菌体生物扩增技术检测牛结核分枝杆菌的方法研究

建立噬菌体生物扩增技术检测牛结核分枝杆菌试验方法,探讨最佳检测条件。比较各种检测方法对测定结果的影响。结果:噬菌体工作浓度为1×108PFU/ml、37℃感染2h,杀毒剂浓度在100mmol/L、室温作用10min为最佳检测条件。指示细胞浓度在1×106条/ml时,形成噬菌斑清晰,便于计数。结论:在选择最佳测定条件下,噬菌体生物扩增法检测牛结核分枝杆菌,快速、简便、灵敏。     

天津市动物强制免疫疫苗“先打后补”试点

2016年,天津市作为全国首批试点省份,在全市规模场试行“先打后补”政策。3年来,通过前期细化方案,落实补贴经费,调整防疫管理方式等工作的实施,在推进养殖者主体责任落实,提升免疫政策投入效果等方面成效明显,但鉴于养殖者积极性差、试点初期政策门槛高、补贴到位率低、养殖者自主监测意识弱等问题,提示应简化政策实施程序,建立免疫服务市场,加大政策宣传力度,强化监测与执法衔接,以建立健全强制免疫“先打后补”管理机制,实现养殖者自主免疫,落实防疫主体责任的目标。     

Regulation by reactive oxygen species of matrix metalloproteinase-1, 3 and tissue inhibitor of matrix metalloproteinase-1 in smooth muscle cells

AIM: To understand whether reactive oxygen species promote the rupture of atherosclerotic plaques by regulating the balance of matrix metalloproteinase-1, 3 (MMP-1, 3) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in smooth muscle cells. METHODS: Aortic smooth muscle cells from 4-6months-healthy abortive fetuses were incubated for 24 hours with xanthine (100 μmol/L) and xanthine oxidase (5 U/L) in vitro . MMP-1, 3 and TIMP-1 in the concentrated culture media were measured by Western blotting ( n =3 independent experiments). RESULTS: Incubation with xanthine/xanthine oxdiase decreased the amount of MMP-1 in the aortic smooth muscle cells (21.2%±5.5% of the control group), and pro-MMP-1 was activated completely. Reactive oxygen species (ROS) also activated pro-MMP-3, and increased the production of MMP-3 in the aortic smooth muscle cells. On the other hand, ROS inhibited the production of TIMP-1 in the aortic smooth muscle cells. CONCLUSION: It is complicated that ROS regulates the balance of MMPs and TIMPs. ROS may contribute to matrix degradation and the rupture in the atherosclerotic plaques.     

木本藤本植物在城市绿化中的应用现状及发展趋势

随着城市化的发展,城市立体绿化在改善城市生态环境方面的作用显得越来越重要.木本藤本植物在城市立体绿化中具有其他植物不可比拟的优势,因此也得到了广泛的研究与应用.在广泛查阅文献资料及调查京津两地木本藤本植物应用的基础上,分析总结了木本藤本植物在我国城市绿化中的研究概况及其应用现状,提出应重视野生木本藤本植物的生理生态学特性研究,加强野生木本藤本植物的引种、驯化、扩繁以及新品种的培育,同时深入调查做好野生木本藤本植物资源的保护.     

hHT/GFP融合基因表达载体的构建及在小鼠成纤维细胞中的表达

为探讨超急排斥反应(hyperacute rejection,HAR)及延迟性异种排斥反应(delayed xenograft rejec-tion,DXR)分子调控机制,进行-α1,2岩藻糖苷转移酶基因(hHT)与绿色荧光蛋白基因(green fluorescent protein,GFP)融合表达载体pEGFP-C1-hHT的构建及在小鼠成纤维细胞表达的研究。采用脂质体法转染小鼠成纤维细胞48 h后观察到GFP阳性细胞。同时对GFP阳性小鼠成纤维细胞进行PCR及Western blot,检测hHT基因的整合及表达情况。PCR结果表明hHT基因整合入小鼠基因组,Western blot检测到hHT基因的表达。研究结果表明,成功克隆hHT基因并构建了融合表达载体pEGFP-C1-hHT,可应用于进一步转基因研究。     

贵阳市金阳新区观山公园概念性规划

本文在对贵阳历史文化特色和地理条件调查分析的基础上进行规划设计,从公园的规划指导思想与规划目标、布局特色、总体规划等方面进行阐述,在充分挖掘立地特点与文化脉络的同时,解决开发与保护,继承与发扬的对立统一的关系,使观山公园成为展示园林景观、地域文化和城市特征的媒介。