4种除草剂对云杉矮槲寄生的防治试验

云杉矮槲寄生害是青海省三江源地区青海云杉林的重要病害。选用4种不同的除草剂,对云杉天然林中的云杉矮槲寄生植物进行防治试验。结果表明,比例为1∶100的绿枯和比例为1∶200的易圃净防治效果最好,且无明显药害症状;一把火百草枯的3种比例虽然具有防治效果,但是均产生不同程度药害,其他几种除草剂及其比例也有一定的防治作用,但效果显著低于比例为1∶100的绿枯和比例为1∶200的易圃净。     

Synthesis P-M0 Phenolic-Formaldehyde Resin with orthogonal experiment method

In this paper the synthesis of P-M 0 Phenolic-formaldehyde resin have been studied and technological parameters have been determined with orthogonal experiments. Furthermore the optimum technology for he synthesis of P M 0 Phenolic formaldehyde resin have been obtained.     

同步辐射(软X射线)对冬小麦的诱变效应及机理研究Ⅲ.辐照种子产生的自由基和辐照引起种胚DNA非按期合成的研究

应用电子自旋 (ESR)波谱术研究了同步辐射辐照种子产生的自由基及其与辐射损伤之间的关系。结果表明 ,同步辐射辐照的种子产生了大量的自由基 ,其种类、性质不同于γ射线 ,短寿命自由基 (小于 48h)产额高于γ射线 ,长寿命自由基 (大于48h)的稳定性大于γ射线。同步辐射自由基产额与辐照剂量呈线性关系。用3H TdR掺入法研究了受辐照种胚萌发早期DNA的合成动态 ,结果表明 ,同步辐射能够引起种胚DNA的损伤修复合成 ,其特点不同于γ射线。原冬 6号和北京41 1品种的DNA修复合成出现在种胚吸水后第一个正常的DNA合成峰之前 ,京冬8号品种出现在第一个小峰之后和 2个高峰之前     

儿茶素组成和理化条件对茶黄素酶催化合成的影响

利用梨果实多酚氧化酶,在单因素试验基础上,设计正交试验,进行酶性合成茶黄素,研究儿茶素组成和理化条件对茶黄素合成的影响,以确定最佳反应条件。结果表明,以儿茶素混合物C(EGC>200mg/g,EGCG>200mg/g,儿茶素总量>500mg/g)为材料,茶黄素酶促合成的最佳条件为:反应体系的最佳pH值为5.5,温度为30℃,底物浓度为5mg/ml,酶添加量为75ml/1000mg,最佳反应时间40min。pH值和儿茶素浓度是反应体系中两个重要的影响因子(P<0.05)。     

Paper Synthesis,Cytotoxicity and Apoptosis Induction in Human Tumor Cells by Galaxamide and Its Analogues

Our previous study reported that galaxamide, which is a cyclo-pentapeptide containing five leucines that was extracted from Galaxaura filamentosa, displayed remarkable anticancer cytotoxicity. This novel cyclo-peptide provided a new skeleton for the structural modifications used in finding new drugs with better anticancer properties. In this study, five analogues were synthesized based on changing the number of d/l amino acids by adding a new amino acid, phenylalanine. Galaxamide and five of its analogues were evaluated through MTT assays to examine their cytotoxic activities. We found that modified analogue 5, which is referred to as A5, displayed broad spectrum cytotoxic activity toward every cell line tested; in addition, the IC₅₀ of A5 was lower than that of galaxamide and the other analogues. Furthermore, we used flow cytometry and western blot assays to investigate whether galaxamide and A5 could induce cancer cell apoptosis. The flow cytometric studies showed that HepG2 cells treated with different concentrations of galaxamide or A5 over 72 h displayed significant and dose-dependent increases in the percentages of early-stage apoptotic cells. Western blotting revealed that both compounds induce caspase-dependent apoptosis in HepG2 cells through a mitochondria-mediated pathway. The results demonstrate that galaxamide and its analogues have potential applications as clinical anticancer drugs.     

葡萄VvERF90的克隆及对乙烯合成基因的调控研究

ERF转录因子为植物特有的一类转录因子,在调控植物乙烯合成过程中发挥着重要功能。为研究葡萄ERF转录因子在调控乙烯合成过程中的作用,以阳光玫瑰(Vitis labruscana Baily × V. vinifera L.)葡萄穗梗为材料,克隆了乙烯响应因子VvERF90,并进行了生物信息学分析和基因功能分析。结果表明,VvERF90属于第IX亚家族,与苹果MdERF2和MdERF3的亲缘关系较近;VvERF90可以正调控VvACO1的表达;VvERF90在拟南芥中过量表达后,转基因植株中VvACO1的同源基因AtACO3基因表达量明显升高,转基因植株的乙烯释放量增加2倍,植株变矮。上述结果表明,VvERF90可能通过调节VvACO1的表达,调控乙烯的释放水平。本研究结果为进一步探明葡萄中乙烯合成的调控机制奠定了理论基础。     

#br# 新型电动四轮农用车牵引性能研究#br#

针对传统燃油农用车辆在环保、动力等性能方面存在的不足,研制一种新型电动四轮农用车辆,对样机进行牵引性能测试。针对作业和行驶工况,提出后轮电机中央驱动、前轮轮毂电机独立驱动的新型电动四驱动力系统方案,对整机牵引动力学进行分析,并进行牵引性能实车试验和经济性分析。研究表明,新型电动四轮农用车具有较好的牵引性能和经济性：牵引性能方面,后轮驱动的最大牵引力为1 925 N,最大牵引效率为74%;经济性方面,中耕作业单位面积能量消耗降至传统燃油拖拉机的42.4%,单位面积成本费用降至传统燃油拖拉机的80.1%。该机适应温室大棚等设施农业、观光休闲农业等绿色环保的新型农业生产方式快速发展的需要,也为全新电动农业车辆设计提供参考。     

Pathophysiological Effects of Synthetic Derivatives of Polymeric Alkylpyridinium Salts from the Marine Sponge,Reniera sarai

Polymeric 3-alkylpyridinium salts (poly-APS) are among the most studied natural bioactive compounds extracted from the marine sponge, Reniera sarai. They exhibit a wide range of biological activities, and the most prominent among them are the anti-acetylcholinesterase and membrane-damaging activity. Due to their membrane activity, sAPS can induce the lysis of various cells and cell lines and inhibit the growth of bacteria and fungi. Because of their bioactivity, poly-APS are possible candidates for use in the fields of medicine, pharmacy and industry. Due to the small amounts of naturally occurring poly-APS, methods for the synthesis of analogues have been developed. They differ in chemical properties, such as the degree of polymerization, the length of the alkyl chains (from three to 12 carbon atoms) and in the counter ions present in their structures. Such structurally defined analogues with different chemical properties and degrees of polymerization possess different levels of biological activity. We review the current knowledge of the biological activity and toxicity of synthetic poly-APS analogues, with particular emphasis on the mechanisms of their physiological and pharmacological effects and, in particular, the mechanisms of toxicity of two analogues, APS12-2 and APS3, in vivo and in vitro.     

Total Synthesis and Structure-Activity Relationship of Glycoglycerolipids from Marine Organisms

Glycoglycerolipids occur widely in natural products, especially in the marine species. Glycoglycerolipids have been shown to possess a variety of bioactivities. This paper will review the different methodologies and strategies for the synthesis of biological glycoglycerolipids and their analogs for bioactivity assay. In addition, the bioactivities and structure-activity relationship of the glycoglycerolipids are also briefly outlined.     

Profiling of Polar Lipids in Marine Oleaginous Diatom Fistulifera solaris JPCC DA0580: Prediction of the Potential Mechanism for Eicosapentaenoic Acid-Incorporation into Triacylglycerol

The marine oleaginous diatom Fistulifera solaris JPCC DA0580 is a candidate for biodiesel production because of its high lipid productivity. However, the substantial eicosapentaenoic acid (EPA) content in this strain would affect the biodiesel quality. On the other hand, EPA is also known as the essential health supplement for humans. EPAs are mainly incorporated into glycerolipids in the microalgal cell instead of the presence as free fatty acids. Therefore, the understanding of the EPA biosynthesis including the incorporation of the EPA into glycerolipids especially triacylglycerol (TAG) is fundamental for regulating EPA content for different purposes. In this study, in order to identify the biosynthesis pathway for the EPA-containing TAG species, a lipidomic characterization of the EPA-enriched polar lipids was performed by using direct infusion electrospray ionization (ESI)-Q-TRAP-MS and MS/MS analyses. The determination of the fatty acid positional distribution showed that the sn-2 position of all the chloroplast lipids and part of phosphatidylcholine (PC) species was occupied by C16 fatty acids. This result suggested the critical role of the chloroplast on the lipid synthesis in F. solaris. Furthermore, the exclusive presence of C18 fatty acids in PC highly indicated the biosynthesis of EPA on PC. Finally, the PC-based acyl-editing and head group exchange processes were proposed to be essential for the incorporation of EPA into TAG and chloroplast lipids.