新加坡“空中绿化”的实践与成效

新加坡是一个极具热带特色的岛国,有“花园城市”美誉。进入新世纪,新加坡强制推行“空中绿化”后,使其“花园城市”转变为“花园中的城市”、“平面花园”转变为“立体花园”,成为区域城市的“空中绿化”典范。文章回顾了“空中绿化”概念的发展、历史和现状,结合对新加坡“空中绿化”的实地考察,介绍了空中绿化新技术及空中绿化的优秀作品...     

TCS 在民航机场地下供油管网泄漏检测中的应用

结合TCS在新广州白云国际机场供油系统停机坪地下管网泄漏检测中的应用，探讨了适用于国内民航机场停机坪供油管网的泄漏检测方法及实施方案。TCS系统采用压力阶梯法进行泄漏检测，其基本原理：用两个不同的压力连续地对密闭管段加压至两个已设定的相对高、低的压力值，通过比较高、低压力下管段压力值的变化曲线，确定泄漏系数值，进而判断泄漏情况。该系统适用于已建管道，安装、改造费用低；检测周期短，约50min；检测精度高，可达0．04L／（h·m3）。（图3，参6）     

泥炭、蛭石与稻田土混配基质对机插秧苗素质及栽插质量的影响

以泥炭、蛭石和水稻土为原料混配成不同水稻育秧基质（CK,100%稻田土;T1,50%稻田土+50%泥炭;T2,50%稻田土+30%泥炭+20%蛭石;T3,25%稻田土+75%泥炭;T4,25%稻田土+50%泥炭+25%蛭石;T5,33.3%稻田土+33.3%泥炭+33.3%蛭石）,研究不同基质的理化性状及其对水稻秧苗素质、机插质量和毯秧质量的影响,筛选适合广东本地化的育秧基质。结果表明,与CK相比,混配基质容重显著降低34.16%~57.25%,总孔隙度提高9.99%~15.82%,通气孔隙和持水孔隙明显改善;除T3外,混配基质均具有壮秧作用,以T4效果最好,株高、百株地上部干物质量、根系盘结力分别比CK提高了24.49%、31.79%和26.11%,T5次之;秧苗素质以T4、T5最好,成秧率、壮苗指数分别比CK显著提高了16.63%~17.91%和30.00%~36.57%,毯秧质量减轻了20.52%~22.43%;栽插质量以T4、T5最好,丛苗数是CK的1.31~1.34倍,漏秧率、漂秧率和伤秧率分别比CK降低了3.48%~3.97%、2.28%~2.46%、1.93%~2.69%。综上,在本试验条件下,T4和T5为较佳的育秧基质配方。     

Selenium-enriched Spirulina platensis promotes proliferation of hepatocytes in rat partial hepatectomy

AIM: To explore the effects of selenium-enriched Spirulina platensis (Se-SP) on proliferation of hepatocytes in rat hepatectomy. METHODS: Rat hepaectomy model was conducted using male Wistar rats. The rats were randomized into five groups: operation groups with 150 (H), 50 (M) and 15 (L) mg·kg^-1·d^-1 of Se-SP, placebo-control (P) and sham operation group (F). Activities of glutathione peroxidase (GPx) and thioredoxin reductases (TR) in hepatocytes were determined by chemical colorimetry. The expression index of proliferating cell nuclear antigen (PCNA) in hepatocytes was detected by immunohistochemistry, and the level of ［³H］-TDR incorporation in regenerative hepatocytes was analyzed by radio-immunity. RESULTS: Activity of GPx and TR, PCNA expression index as well as ［3H］-TDR insertion in hepatocytes (in vitro) were obviously higher (P<0.05) in L groups than those in P and F groups. All parameters were significant changed (P<0.05) after operation in H, M, L and P groups whereas some slightly change in F group. Furthermore, correlation analysis showed that the levels of GPx and TR in hepatocytes all showed positive correlation with PCNA expression (r²=0.77 and 0.87, respectively) and with ［³H］-TDR incorporation level (r² = 0.73 and 0.84, respectively) in hepatocytes. CONCLUSION: Se-SP enhances hepatocyte proliferation in rat hepatectomy, up-regulation of selenoenzymes might be responsible for this effect.     

重组酶聚合酶扩增技术(RPA)快速检测玉米褪绿斑驳病毒

玉米褪绿斑驳病毒(maize chlorotic mottle virus,MCMV)是我国颁布的一种禁止进境的检疫性有害生物,自然寄主有玉米、小麦、黍、大麦等。自然情况下,MCMV常与甘蔗花叶病毒(sugarcane mosaic virus,SCMV)、玉米矮花叶病毒(maize dwarf mosaic virus,MDMV)、小麦线条花叶病毒(wheat streak mosaic virus,WSMV)共同侵染玉米,可造成玉米产量损失高达10%~90%(Hilker et al.,2017)。     

番茄褐色皱果病毒TaqMan 荧光定量RT-PCR检测方法的建立及应用

为建立番茄褐色皱果病毒(tomato brown rugose fruit virus, ToBRFV)TaqMan荧光定量RT-PCR方法，本研究针对ToBRFV RNA依赖的RNA聚合酶(RNA-dependent RNA polymerase, RdRP)基因序列设计了4组特异性引物和TaqMan探针，构建了标准曲线，并对该方法的特异性、灵敏度和实际样品的检测效率进行评估。结果显示，该方法特异性强，与番茄花叶病毒、番茄斑驳花叶病毒、烟草花叶病毒、黄瓜绿斑驳花叶病毒、番茄环斑病毒、番茄黑环病毒、辣椒轻斑驳病毒、烟草环斑病毒和凤果花叶病毒等9种病毒均无交叉反应。建立的标准曲线的R²为0.999,扩增效率为102.096%,检测灵敏度为10 fg/μL,与EPPO PM 7/146(1)推荐的CaTa28、CSP1325方法相当，是常规RT-PCR的100倍；采用该方法成功从60份番茄和辣椒叶片、种子样品中检出10份阳性样品。建立的TaqMan荧光定量RT-PCR方法特异性强、灵敏度高，适用于实际样品中ToBRFV的快速精准检测。