H5亚型禽流感灭活疫苗的研制

以H5N1亚型禽流感病毒接种鸡胚，收取鸡胚液为抗原研制了禽流感灭活疫苗，并对制苗抗原以及疫苗的物理性状、安全性、免疫效力、免疫剂量和保护期等进行了试验。结果表明，获得了较高效价的制苗抗原．灭活前后HA分别为2^10.0-11.0和2^9.0-10.0。试制疫苗物理性状符合要求，安全性良好。试验鸡在免疫14d后血清抗体达到2^7.5，210d血清HI抗体仍维持在2^5.0左右；免疫后18d使用高致病性H5亚型禽流感病毒攻毒，获得100％的保护。分别使用0．1，0．3和0．5mL免疫鸡，发现0．3～0．5mL剂量组免疫后血清抗体达到2^7.4-8.0。疫苗在2～8℃保存540d，疫苗物理性状没有改变，免疫后血清HI抗体可以达到2^7.5。这提示研制的疫苗可以有效控制禽流感H5亚型的流行。     

利用原生质体再生恢复核盘菌菌株Ep—1PN毒性的研究

分析了６９个随机挑选的核盘菌弱毒菌株Ｅｐ－１ＰＮ原生质体再生后代的生长速度、菌 落形态和毒性。结果表明：其中的３５个再生后代在ＰＤＡ平板上均匀扩展,形成典型的核盘菌菌落,生长速度大于１８ｍｍ／ｄ。在离体莴苣杆上,这些后代的培养物引起较大的病斑。当它们同亲合性菌株Ｅｐ－１ＰＮＡ１８３在ＰＤＡ平板上接触时没有发现Ｅｐ－１ＰＮＡ１８３菌落发生异常变化,说明这些后代已失去了Ｅｐ－１ＰＮ的弱毒因子,恢复了正     

紫甘蓝COP1基因的克隆及表达模式分析

光照是植物生长发育的一个重要的环境因素,COP1是光调控植物发育的一个分子开关。本实验以"早红"紫甘蓝为实验材料,分两组置于光照(光照16h,28℃;黑暗8h,18℃)及完全遮光培养箱培养,至幼苗时提取RNA,进行COP1的cDNA克隆,并通过半定量RT-PCR方法分析COP1在不同处理下的表达情况。结果表明:COP1 cDNA全长为1863bp,编码620aa,分子量为70.325kD;在无光条件下生长的紫甘蓝幼苗虽然仍有少量花青素合成,但是其花青素含量明显低于光照条件下生长的紫甘蓝幼苗;COP1基因在无光条件下的表达量明显强于有光条件,表明COP1对紫甘蓝中花青素的合成起负调控作用。本文旨在探索在不同光照条件下紫甘蓝中COP1基因与其花青素合成的关系,为后期揭示花青素表达调控机制奠定基础。     

Single and Interactive Effects of Temperature and Light Quality on Four Canola Cultivars

Combined effects of temperature and light quality on plants have received little attention. We investigated the single and interactive effects of temperature and light quality on growth and physiological characteristics of four canola (Brassica napus) cultivars – Clearfield 46A76 (cv₁), Clearfield 45H72 (cv₂), Roundup Ready 45H24 (cv₃) and Roundup Ready 45H21 (cv₄). Plants were grown under lower (24°/20 °C) and higher (30°/26 °C) temperature regimes at low red/far‐red (R/FR), normal R/FR and high R/FR light ratios in environment‐controlled growth chambers (16 h light/8 h dark). Higher temperature reduced stem height and diameter; leaf number and area; dry matter of all plant parts; and specific leaf weight, but increased leaf area ratio; and chlorophyll (Chl) fluorescence (Y). Low R/FR increased stem height; Y; and ethylene, but decreased stem diameter; F_v/F_m; Chl a; Chl b; and carotenoids. Among cultivars, plants from cv₄ were tallest with thickest stems and greatest dry matter. None of the main factors affected gas exchange. Higher temperature at high R/FR caused cv₃ to be shortest, whereas lower temperature at low R/FR caused cv₄ to be tallest. We conclude that heat and other stress factors will adversely affect sensitive crops, but tolerant genotypes should perform well under future climate.     

The effects of ethylene, 1-MCP and AVG on sprouting in sweetpotato roots

Exogenous ethylene is commonly used as a commercial sprouting inhibitor of potato tubers. The role of ethylene in the control of sprouting of sweetpotato roots, however, is not known. The aim of this study was to investigate the role of ethylene in control of sprouting in sweetpotato roots by observing the effect of an ethylene synthesis inhibitor, aminoethoxyvinylglycine (AVG), and the ethylene antagonist, 1-methylcyclopropene (1-MCP), in the presence and absence of exogenous ethylene on root sprouting and associated sugar accumulation. Continuous exposure to 10 μl L⁻¹ ethylene, 24 h exposure to 625 nl L⁻¹ 1-MCP or dipping in 100 μl L⁻¹ AVG all inhibited sprout growth in sweetpotato roots of two varieties over 4 weeks of storage at 25 °C. The observations that both ethylene on its own and 1-MCP, which inhibits ethylene action, inhibit sprout growth indicate that while continuous exposure to exogenous ethylene leads to sprout growth inhibition, ethylene is also required for sprouting. In potato tubers ethylene is required to break dormancy, while continuous exposure inhibits sprout growth.Monosaccharide concentrations in ethylene, 1-MCP or AVG treated roots were lower than in untreated roots, and for ethylene treated roots this was associated with higher respiration rates. This is consistent with the activation of some additional process by ethylene which uses energy through sugar metabolism. 1-MCP and AVG both inhibited this increase in respiration rate and counteracted the decrease in monosaccharide concentrations. 1-MCP presumably counteracts the ethylene stimulation of this process, while the effect of AVG is attributed to its possible inhibitory effects on protein synthesis.     

灌溉预报与节水灌溉决策专家系统研究

从节水灌溉的基本原理入手，分析灌溉预报中的各个参量，提出了节水灌溉决策的依据、方法及评价标准。介绍了灌溉预报决策专家系统中由框架库、规则组库和黑板3部分组成的综合知识体结构的知识表示技术。     

Analysis of Nitrite Accumulation During Denitrification

To realize the purpose of enhanced nitrogen removal (TN<5 mg·L-1) in step feed process treating urban wastewater, by using SBR reactor, the nitrite accumulation, variation of pH and ORP as well as dynamic properties during denitrification with methanol and glucose as the sole carbon sources are investigated in details. The results show that for both carbon sources, serious nitrite accumulations are observed during denitrification under different ratios of nitrogen and carbon (C/N). With identical C/N, when glucose is used as carbon source there is more maximum NO2--N accumulation concentration. However, NO3--N reduction rate is faster than NO2--N reduction rate for both carbon sources. Furthermore, with the increase of C/N, the maximum NO2--N concentration increases and the time in which the NO2--N achieves the highest concentration is accordingly shortened. For glucose, however, under high C/N ratio (C/N=29.3) both the denitrification rate and NO2--N accumulation concentration decrease. Besides, the changes of pH and ORP reflect the variation of NO2--N accumulation concentration well because pH and ORP have the significant relationship with NO2--N concentration. The second inflexion on curves indicates the real end of denitrification process.     

Aβ1-42淀粉样蛋白在大肠杆菌中的可溶性表达

本研究中用融合标签技术通过单质粒转化和双质粒转化分别促进Aβ1-42淀粉样蛋白的可溶性表达。构建重组载体pET（yd-b42）、pET（Msb-b42）、pET（Od-b42）、pAY-sls[ydb42]、pAY-sls[tydb42],并在大肠杆菌中表达,通过SDS-PAGE验证分析。标签yd、Msb、Od、tyd都能很好的促进Aβ1-42淀粉样蛋白可溶性表达,其中yd、tyd的促溶效果最好。Aβ1-42淀粉样蛋白能在大肠杆菌中可溶性表达。为阿尔茨海默病的治疗提供进一步理论基础。     

南水北调西线一期工程研究

南水北调西线工程是一项非常宏大的水利工程,工程建设对我国经济发展和社会进步具有十分重要意义。概述了南水北调西线一期工程从论证、超前期规划研究到工程实施的发展过程,介绍了调水工程区地质条件、主要活动断裂及其组合特征,分析了可用水量、存在的主要地质问题以及工程建设对环境和社会的影响,并提出了今后研究应注意的几个问题。     

SPE-HPLC-MS/MS法测定人参及土壤中氟硅唑的残留及风险评估

【目的】明确人参和土壤中氟硅唑的残留量,并对可能产生的膳食风险进行评估,以确保人参产品的质量安全.【方法】在集安市和抚松县进行2年试验,采用固相萃取-高效液相色谱-串联质谱法测定了400 g·L-1氟硅唑乳油在人参根及土壤中的残留消解及最终残留量,并采用风险商值法对人参中氟硅唑可能产生的膳食风险进行了评估.【结果和结论】施药剂量为90 g·hm-2(以有效成分计)时,氟硅唑在人参根和土壤中的降解半衰期分别为7.85~9.94和5.59~7.13 d.施药剂量为60~90 g·hm-2时,施药后35 d氟硅唑在人参根和土壤中的残留量分别小于0.043 3和0.037 5 mg·kg-1.风险商值为4.59×10-5,风险较低,处于安全水平.建议我国在人参中氟硅唑的最大残留限量值可暂定为0.05 mg·kg-1,安全间隔期为35 d.