不同药剂防治射干锈病试验初探

为筛选防治射干锈病的适宜药剂,2016年7-8月在贵州省长顺县进行了申嗪霉素、戊唑醇、苯醚甲环唑3种药剂防治射干锈病药效筛选试验。结果表明,3种药剂处理对射干锈病均有良好防效,二次药后10d的防治效果均在60%以上,三次药后15d的防治效果均在80%以上,防治射干锈病,在优先使用生物农药申嗪霉素的基础上,做到与其他药剂轮换使用效果较好。     

芦苇种子萌发对不同环境因子的响应

以扎龙湿地芦苇种子为试验材料,采用培养皿室内培养的方法,研究不同培养基质、不同萌发温度、不同基质埋藏深度和不同基质水分饱和度条件下芦苇种子的萌发过程,比较不同处理条件对芦苇种子萌发的影响.结果表明,不同培养基质条件下芦苇种子萌发过程呈现“S”型曲线,种子发芽率均较高,土壤培最高(达94％),滤纸最低(为82.6％),发芽势土壤最高(为93.34％),滤纸最低(为71.34％);芦苇种子低于20℃恒温培养很难发芽,20～30℃随温度的增高芦苇发芽率和发芽势均呈增加趋势;蛭石培1～6 mm埋深芦苇种子均能出苗,发芽率2 mm埋深最高(为96％),土壤培仅在1～2 mm埋深时出苗,发芽率和发芽势1 mm埋深最高;蛭石培、土壤培在80％水分饱和度发芽率最高(分别为93.34％、90％).不同培养条件对芦苇种子萌发影响较大,蛭石在30℃、80％水分饱和度、2 mm埋深为芦苇种子萌发的最适条件.     

CUDC-907 induces DNA damage and autophagy in glioma cells

AIM:To investigate the effect of CUDC-907, a dual histone deacetylase (HDAC) and phosphatidylinositol 3-kinase (PI3K) inhibitor, on the DNA damage, cell cycle distribution and autophagy in human glioma U251 cells. METHODS:U251 cells were treated with CUDC-907 of different concentrations, and the cell viability was detected by MTT assay. The quantitative γ-H2AX foci were determined by laser scanning confocal microscopy. The cell cycle distribution of U251 cells was examined by flow cytometry. The protein expression was determined by Western blot analysis. RESULTS:CUDC-907 inhibited the cell viability and the phosphorylation of Akt and p70 ribosomal protein S6 kinase (p70s6K) in the U251 cells (P<0.05). In CUDC-907-treated cells, the number of γ-H2AX foci and protein expression of γ-H2AX were increased significantly (P<0.05). CUDC-907 also induced cell arrest in the G₂/M phase by up-regulating the expression of p21, and inhibiting the protein level of cyclin B1 and the phosphorylation of cell division cycle protein 2 (Cdc2). In addition, CUDC-907 triggered cell autophagy, and inhibition of autophagy increased CUDC-907-induced DNA damage of U251 cells. CONCLUSION:CUDC-907 significantly inhibits PI3K/Akt signaling pathway, induces DNA damage and arrests cell cycle in G₂/M phase. Blockage of autophagy promotes CUDC-907-induced DNA damage of U251 cells.     

Captopril exerts myocardial protective effect in coronary microembolization rats by inhibiting oxidative stress injury and alleviating inflammatory response

AIM: To investigate the effects of captopril (CAP) on oxidative stress injury and inflammatory response induced by coronary microembolization (CME) and its related molecular mechanisms. METHODS: The rat model of CME was established by clamping the rat artery and injecting blood microemboli. The rats were divided into control group, CME group and CME+CAP group, with 6 rats in each group. The myocardial tissues of each group were collected. The changes of myocardial structure and the degree of inflammatory response were analyzed by HE staining. Cardiomyocyte apoptosis was detected by TUNEL staining. The fluorescence intensity of cleaved caspase-3 was detected by immunofluorescence obervation. The protein levels of cleaved caspase-3 and Bax were determined by Western blot. The activity of superoxide dismutase (SOD) and catalase was measured by ELISA. The production of reactive oxygen species (ROS) was detected by DHE fluorescence staining. RESULTS: CAP significantly reduced the myocardial structural changes (P<0.05), inflammatory cell infiltration (P<0.01), number of apoptotic cardiomyocytes (P<0.01), the protein levels of cleaved caspase-3 and Bax (P<0.01), and ROS production levels (P<0.01), but promoted the activity of antioxidant markers SOD and catalase (P<0.01) in the CME rats.CONCLUSION: CAP attenuates CME-induced myocardial injury by resisting oxidative stress and alleviating inflammatory response.     

温室环境因子驱动甜瓜水分传输机理分析与模拟

利用人工气候室控制空气温度、相对湿度和光合有效辐射量,根据水量平衡法控制土壤含水率,按照四因素五水平的二次回归正交旋转组合设计,对甜瓜蒸腾量进行模拟,并探讨各因子调控水分传输的机制。基于Jarvis模型建立环境因素驱动的多元非线性气孔导度模型,结合水汽扩散原理建立蒸腾量模型,模型预测精度良好。探究因素交互作用及其耦合调控效应,结果表明:除相对湿度对蒸腾表现为抑制作用,土壤含水率、空气温度和光合有效辐射均对蒸腾具有促进作用;土壤含水率与空气温度的单因素效应相似,随因素水平增加,蒸腾量线性升高;光合有效辐射量驱动蒸腾的单因素效应为开口向下的二次函数,当因素水平超过阈值后,蒸腾量逐渐下降。环境因素在驱动和调控蒸腾过程中均存在密切耦合和反馈效应,土壤含水率与温度对蒸腾调控的耦合效应趋近于平滑曲面,蒸腾量随两因素水平的升高而升高,在试验水平内两因素对蒸腾表现为协同促进效应;空气相对湿度减弱了水汽扩散驱动力,进而抑制温度和土壤含水率对蒸腾的驱动作用,且这种抑制作用随相对湿度的升高而更明显。     

混合悬架半主动控制器设计与试验

为改善传统被动悬架的动力学性能,回收悬架振动能量,设计了一种半主动混合悬架系统。建立1/4车动力学方程,分别研究馈能回路处于Boost模式和Buck模式时馈能回路内电流的变化情况,并分析MOS管占空比对直线电动机电磁阻尼力的影响。在此基础上,引入基于天棚和地棚混合控制的半主动控制策略。提出半主动控制参考力的概念,并运用粒子群算法确定其最优控制参数。通过对不同工作模式下电路电流的追踪,达到对电动机电磁阻尼力实时控制的目的。接着运用Simulink仿真搭建混合悬架系统模型,分别进行动力学性能、馈能性能以及电流跟踪控制效果对比。仿真结果表明,半主动混合悬架能够在改善车辆动力学性能的同时回收部分振动能量,所设计的半主动控制器对电流有较好的控制效果。最后,进行台架试验,通过对比试验结果验证了仿真结果的正确性。     

施用控释尿素对大豆吸氮量及产量的影响研究

试验研究施用控释尿素对大豆吸N量及其产量与品质的影响结果表明 ,控释尿素比普通尿素N肥利用效率提高 3 0 6 %～ 1 1 93% ,沙土中尿素N残留量增加 1 2 5 %～ 1 5 89% ,大豆产量提高 2 1 6 9%～ 4 9 2 2 % ,且改善大豆品质。     

寒地水稻抽穗期长短与温度关系研究

试验分析的结果表明：寒地水稻不同品种发生早穗现象的程度及危险性不同；抽穗期长短与移栽时秧龄、移栽后第11～20d积温、21～30d积温呈极显著正相关，说明寒地水稻抽穗期拉长造成早穗的主要原因是大秧龄移栽和移栽后遇高温。     

黄土丘陵区退耕地植被景观时空变异特征

对黄土丘陵区退耕地植被特征的时空变异性进行了研究.结果表明,不同植被类型区植被特征之间差异不是很显著,仅延安与安塞在物种丰富度之间和安塞与吴旗在物种多样性之间存在较显著的差异(0.01＜p＜0.05),其它的两两之间的差异并不明显.延安森林带北缘→安塞森林草原带植被指数呈下降趋势,降幅最大为17.65%,变异系数呈增大趋势,增幅最大为21.49%;安塞森林草原带→吴旗草原带物种丰富度指数及其变异系数都呈增大趋势,而物种多样性和均匀度指数呈减小趋势,其变异系数呈增大趋势.植被指数随退耕年限的变化趋势图都有两个明显的峰值,并在退耕20年左右后植被群落逐渐稳定.     

野生斑鳠西江地理群的遗传多样性分析

为了解斑鳠(Mystus guttatus)不同地理种群之间的遗传分化程度,基于RAPD技术,分析了珠江水系西江段野生斑鳠的遗传多样性。利用20个随机引物对30个斑鳠个体的基因组DNA进行了PCR扩增,共扩增出3210条DNA片段,平均每个个体扩增出107条带。在检测到的107个位点中,多态位点数为48个,占44.9%,仅有一个引物S30没有扩增出多态带。个体间最大的遗传距离0.2804,最小的遗传距离0.0467,平均遗传距离0.1526±0.037,种群内个体间平均的相似率为84.7±3.7%。