云龙河三级水电站大坝下游消能区边坡稳定有限元分析

采用有限单元法研究云龙河三级水电站大坝下游消能区泄洪冲刷坑对边坡稳定性的影响.以开挖的方式模拟泄洪冲刷坑,分析冲刷坑对两岸边坡应力状态、变形状态及稳定性的影响;模拟了两组优势节理,分别研究了岩块和两组节理的点安全度及屈服区分布;采用遗传算法搜索了可能最危险滑动面;阐述了评价大坝下游消能区泄洪冲刷坑对边坡稳定性不利影响的方法.     

海洋渔业转型系统的构建及运行机制分析

海洋渔业转型系统的构建是一个复杂的工程,主要由原因子系统、动力子系统、支持子系统和目标子系统四部分构成,各子系统之间相互作用,相互制约,维护着系统的稳定性。当然,要保证整个系统的顺利运行还需要一系列的保障条件,主要包括物质资本、人力资本、风险、技术、环境、社会服务及政府政策等各方面的保障因素,各个方面都影响着转型的每一个环节和每一个过程。     

金秋梨栽培技术

介绍了金秋梨壮苗培育,科学建园,土壤管理和施肥技术以及整形修剪,花果管理和病虫害防治等栽培技术。     

Expression of phenylalanine ammonia-lyase cDNA from rice in E. coli BL21DE3

AIM: To study the expression and its kinetics of rice phenylalanine ammonia-lyase gene encoding into E. coli as the basis of treatment for phenylketouria. METHODS: The phenylalanine ammonia-lyase-1-cDNA(rPAL-1-cDNA) from rice was recombined into E. coli high expression vector pET-28c and transformed into E. coli host strain BL21DE3. Engineering bacteria was then inducted by isopropyl-β-D-thiogalactoside (IPTG) for 1, 3, 5, 7 hours, in order to obtain high level expression. RESULTS: After induction, the expression level of fusion protein was 21.40%, 30.60%, 35.40%, 35.43% respectively. The fusion protein exhibited a band of 78.6 kD on SDS-PAGE analysis, but was not found in controls.The target protein was mainly existed in the form of inclusion body. CONCLUSION:Rice PAL gene expressing E. coli was established by gentic engineering technique.     

Adhesion of bone marrow stromal cell in children with acute lymphoblastic leukemia

AIM and METHOD: The adhesion behavior of bone marrow stromal cells(BMSC) in children with acute lymphoblastic leukemia(ALL) to bone marrow mononuclear cells(BMMC) and Raji cells were investigated by MTT method. The expression of adhesion molecules ICAM-1 and VCAM-1 were detected by flow cytometry. RESULTS: The adhesion ability of BMSC in acute period of ALL to BMMC was lower than that of control group. The adhesion ability of BMSC in long term remission period of ALL to Raji cells higher than that of control group. The expression of ICAM-1 on the surface of BMSC in acute period of ALL is much lower than that of control group. CONCLUSIONS: The adhesion of BMSC to BMMC or tumor cells in children with ALL was abnormal. The abnormal adhesion behavior might be partially due to the changed expression of adhesion molecules on BMSC.     

MicroRNA-142-3p modulates atherosclerosis-associated endothelial cell apoptosis via targeting Rictor

AIM To investigate the role of microRNA-142-3p （miR-142-3p） in endothelial cell apoptosis during atherosclerosis （AS） and the underlying mechanism. METHODS Human aortic endothelial cells （HAECs） were treated with oxidized low-density lipoprotein （ox-LDL）. The expression level of miR-142-3p was detected by RT-qPCR. Apoptosis was determined via flow cytometry （FCM） and caspase-3 activity assay. Prediction of the binding site between miR-142-3p and 3’-UTR of Rictor mRNA was performed by bioinformatics analysis and confirmed by dual-luciferase reporter assay. RESULTS The expression of miR-142-3p was substantially up-regulated during the ox-LDL-elicited apoptosis in HAECs （P<0.05,P<0.01）. Forced expression of miR-142-3p exacerbated apoptosis in HAECs whereas inhibition of miR-142-3p partly alleviated apoptotic cell death mediated by ox-LDL. Further analysis identified Rictor as a direct target gene of miR-142-3p, and Rictor knock-down abolished the anti-apoptotic effect of miR-142-3p inhibitor. Moreover, the Akt/endothelial nitric oxide synthase （eNOS） signaling pathway was found to mediate the beneficial effect of miR-142-3p inhibitor on endothelial cells apoptosis. CONCLUSION Down-regulation of miR-142-3p inhibits endothelial cell apoptosis and atherosclerotic development by up-regulating the expression of Rictor and activating the Akt/eNOS signaling pathway.     

木薯叶片厚度、蜡质含量和气孔密度与抗朱砂叶螨的关系

为明确不同木薯品种的叶片组织结构与抗朱砂叶螨的关系,通过对木薯田间螨害情况的调查,计算出感、抗性稳定的感螨品种华南101、华南124和抗螨品种华南7号、华南13号的螨害指数,同时对叶片的相关物理性状进行测定,分析了叶片厚度、蜡质含量和气孔密度与木薯抗朱砂叶螨的关系。结果表明:4份木薯种质华南101、华南124、华南7号和华南13号的螨害指数依次为89.2%、65.8%、38.3%和0.8%;木薯叶片厚度与螨害指数呈显著负相关;气孔密度与螨害指数呈显著正相关;蜡质含量与螨害指数无显著相关性。上述结果为深入探究木薯抗螨机制提供了初步的理论基础。     

缓释肥减量施用对覆膜栽培玉米生物性状、干物质积累与养分分配的影响

通过大田试验研究缓释肥覆膜减量条件下的玉米生物性状、干物质分配比例、养分含量差异及其与产量的相关性分析。结果表明,与不覆膜(T2)处理相比,覆膜可使玉米的茎粗提高11.05%~19.34%,株高提高2.78%~5.39%,穗位高提高6.20%~10.28%,覆膜条件下缓释肥减量对玉米生物性状无明显影响。覆膜可以使玉米干物质积累提高25.22%~31.01%,较普通复合肥(T6)相比,施用缓释肥更有利于玉米干物质积累,且缓释肥覆膜减量15%(T4)不会影响玉米干物质积累,减量过度(T5)则会显著降低玉米干物质积累以及子粒和茎秆的氮含量。相关分析发现,玉米产量与生物性状存在显著或极显著的相关性,与不同部位养分含量也存在显著或极显著相关性。覆膜条件下施用缓释肥有利于改善玉米生物性状,提高干物质积累和养分含量,玉米茎粗、株高、穗位高与茎秆氮含量、叶片钾含量、子粒氮含量可以作为玉米产量评估的重要指标。     

氮素穗肥运筹对两个杂交中籼稻叶片形态、光合生产及产量的影响

【目的】为探究氮素穗肥不同促花肥和保花肥比例对水稻光合生产和产量的影响,并为水稻氮素穗肥管理提供依据,【方法】以株型和产量均存在较大差异的2个杂交中稻品种(德香4103和宜香3724)为材料,在常规施氮量(180 kg/hm2)下,研究了占总氮40%的穗肥不同促花肥和保花肥运筹比例(1∶3,2∶2,3∶1,4∶0)对水稻叶片生长、形态、光合生产及产量的影响。【结果】2个水稻品种均在低促花肥、高保花肥时(1∶3)表现出叶片直立、受光形态好,净光合速率高和群体干物质积累量大的特点,并最终获得较高产量;而在高促花肥、低保花肥下,2个水稻品种的剑叶、倒2叶叶面积和叶角增大,披垂度增加,群体质量变差,结实率和粒重下降,产量降低。德香4103因其颖花量较大,上3叶叶面积和总叶面积相对适宜,粒叶比高,且在不同穗肥运筹下叶面积和叶角变幅较小,因而受光姿态和群体质量更优,干物质积累量更大,产量更高。【结论】水稻氮素穗肥运筹应塑造良好叶片形态和群体质量,并增加花后物质积累量才能有助于产量提高;并对水稻株叶型选育进行了探讨。     

滨海盐碱地棉花秸秆还田对土壤理化性质及棉花产量的影响

在滨海盐碱地定点设置连续3年棉花秸秆还田和未还田2个处理,研究其对0~60 cm土层土壤理化性质和棉花产量的影响。结果表明,连续3年棉花秸秆还田显著降低0~30 cm土层土壤容重和0~10 cm土层0.25 mm土壤微团聚体含量;显著提高0~10 cm土层5 mm土壤大团聚体含量。在0~20 cm土层,3年秸秆还田显著提高棉花播前和各生育阶段土壤有机质、硝态氮、铵态氮和速效钾含量,平均分别比对照提高13.45%、18.57%、22.80%和22.57%;降低土壤速效磷和含盐量,平均分别比对照降低18.29%和16.59%。在20~40 cm土层,3年秸秆还田显著提高土壤硝态氮和铵态氮含量,平均比对照提高37.20%和31.62%;显著降低土壤含盐量,平均比对照降低19.06%。在40~60 cm土层,3年秸秆还田显著提高土壤硝态氮和铵态氮含量,平均分别比对照提高38.26%和24.83%。3年棉花秸秆还田分别比未还田显著提高棉花籽棉产量11.57%、19.01%和13.24%和皮棉产量18.56%、19.78%和18.73%,但对棉花单铃重和衣分无显著影响。