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41.
42.
SYNERGISM OF CRANBERRY PHENOLICS WITH ELLAGIC ACID AND ROSMARINIC ACID FOR ANTIMUTAGENIC AND DNA PROTECTION FUNCTIONS 总被引:2,自引:0,他引:2
Several studies have shown the antimutagenic DNA protective functions of some naturally occurring phenolic phytochemicals. Emerging research also indicates that synergistic functionality of these phytochemicals in whole foods benefits the management of many diseases. Here we have investigated the potential antimutagenic properties of cranberry phenolics, ellagic acid (EA), rosmarinic acid (RA) and their synergistic interactions on enhancing antimutagenic properties in Salmonella typhimurium tester system against mutagens sodium azide and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine. Ability of these phytochemical treatments to protect oxidative damage to DNA was also investigated using the supercoiled DNA strand scission assay. Results showed that EA was most effective in inhibiting the mutations in S. typhimurium system, whereas RA and EA were equally effective in protecting the DNA from oxidative damage. Results also showed that the antimutagenic functionality of cranberry powder (CP) made from juice extracts was significantly enhanced when 30% (w/w) of phenolics in CP was substituted with RA and EA possibly because of synergistic redox modulation that can influence mutagen function. It is also suggested that the synergistic mixture of cranberry phenolics with RA could also be protecting the cell from mutations by modulating DNA repair systems. 相似文献
43.
热子及热子组合件的常见问题及解决方法 总被引:1,自引:0,他引:1
介绍了阴极加热所用的各种热子及热子组合件,分析了实际应用过程中的常见问题,研制了更加可靠和具有快热性能的熔融热子组件。 相似文献
44.
提出了导线截面利用率的概念,基于S、Z铝型线导体,给出了几种与常用规格圆线同心绞钢芯铝绞线对应的型线同心绞钢芯铝型绞线,将两者的部分基本参数和特性作了对比。结果表明:型线同心绞的钢芯铝型线绞线比圆线同心绞钢芯铝绞线的导体截面利用率约高15%,若截面积相等,钢芯铝型线绞线的直径约减小9%,其他性能几乎相同;若两者直径相等,则钢芯铝型线绞线的导体截面积、单位质量和抗拉力较大,同时直流电阻减小而载流量增大。钢芯铝型线绞线的安装可采用常规金具,具有一定的缓覆冰性能和较好的弧垂特性,将是输电线路使用中的一种重要线种。 相似文献
45.
46.
For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system
when it is machining heavy work piece, a 10-DOF lumped parameter model was made for the machine tool spindle system with geared
transmission. By using the elementary method and Runge-Kutta method in Matlab, the eigenvalue problem was solved and the pure
torsional vibration responses were obtained and examined. The results show that the spindle system cannot operate in the desired
constant rotating speed as far as the gravitational unbalance torque is engaged, so it may cause bad effect on machining accuracy.
And the torsional vibration increases infinitely near the resonant frequencies, so the spindle system cannot operate normally
during these spindle speed ranges. 相似文献
47.
The use of design method considering a coil temperature to maximize the thrust density of a double side coreless permanent
magnet linear synchronous motor (PMLSM) was presented. The optimal current density where the coil temperature reaches an allowable
temperature with heat analysis was applied to a magnetic circuit design. Changing optimal current density is verified whenever
the design parameters of the motor are altered. The design parameters of the motor were applied to thrust calculation. In
this way, the optimal model, which is a reversal of the existing design method, is deduced. The results were compared with
the experimental data to verify their validity. When the convection heat transfer coefficient is applied to other models,
the results of the analysis and test values show good concordance. The method proposed has some limitations. 相似文献
48.
A discontinuity of magnetic circuits according to the end effect is generated in the permanent magnet linear synchronous motor (PMLSM).Due to the unbalanced back electro-motive force (EMF) and impedance produced,unbalanced current is generated.The circulating current,which is caused by a decrease in the thrust,is generated by the unbalanced current.The optimal design of auxiliary-teeth at the end of the mover was carried out to solve the unbalance of phase by using design of experiment (DOE),and compared wi... 相似文献
49.
矿山钻井工程结束后会产生大量的废浆。对这些废浆能否用被用作为地面预注浆浆液进行了一些试验。钻井泥浆和地层注浆所用的浆液有着不同的性能要求,其材料组成也不完全相同,不能直接用于地层注浆。在实验室里,对钻井废弃泥浆和注浆粘土纯浆的相对密度、粘度、pH值和稳定性等物理性能进行了试验,表明二者的粘度和稳定性差别较大。向两种浆液中添加不同数量的水泥和水玻璃,对其粘度、凝胶时间、静切力、塑性强度和抗压强度等性能进行了对比试验和分析,研究结果表明,在添加一定量水玻璃和水泥后,钻井废浆的各种性能与粘土浆液比较接近,可用于地层注浆工程。 相似文献
50.
脉冲溢出型DDS利用相位累加器的溢出信号作为输出信号,很容易用FPGA器件实现,但它输出的脉冲信号存在相位抖动的缺点.作者根据脉冲溢出型DDS的工作原理对其输出脉冲信号的抖动进行了理论分析,得到了输出脉冲信号的频谱表达式,并给出了计算机仿真结果. 相似文献