Effect of anionic-nonionic mixed surfactant on ryegrass uptake of phenanthrene and pyrene from water

The effect of anionic-nonionic mixed surfactant (SDBS-TX100) on the uptake of phenanthrene and pyrene by ryegrass in a hydroponic system was studied, and the influence factors including the com-positions and concentrations of mixed surfactants and the compounds properties were also discussed. The results showed that SDBS-TX100 mixtures with certain compositions and concentrations could enhance the uptake of phenanthrene and pyrene by ryegrass, which could be attributed to the im-proved uptake capacity of ryegrass roots for phenanthrene and pyrene. SDBS-TX100 can enhance the uptake of phenanthrene and pyrene by ryegrass in a wider range of surfactant concentrations (0―0.8 mmol/L) in comparison with corresponding single surfactants, and the maximal contents of phenan-threne and pyrene in ryegrass roots were obtained with the concentrations of SDBS-TX100 around the corresponding critical micelle concentrations. The uptake of phenanthrene and pyrene by ryegrass increased with the increasing mole fraction of SDBS in mixed surfactant solutions, and SDBS-TX100 mixture with a mole ratio of SDBS to TX100 at 9:1 had the greatest capacity in enhancing the uptake of phenanthrene and pyrene, at which the corresponding maximal concentrations of phenanthrene and pyrene in ryegrass roots were 216 and 8.16 times those without surfactants, respectively. Results from this study indicate that the anionic-nonionic mixed surfactants (SDBS-TX100) would be a preferred selection for the application of surfactant-enhanced phytoremediation technology to contaminated soils.     

健身运动对中老年人血糖和血脂浓度的影响

本课题主要对湖南城市学院与益阳职业技术学院的部分从事健身运动的中老年人和运动不足的中老年人的血糖、血脂和体重指数进行比较研究,以探讨健身运动对中老年人血糖、血脂和体重的影响。长期坚持健身运动可提高HDL-C浓度、降低LDL-C浓度,并降低TC/HDL-C和LDL-C/HDL-C比值,有助于维持中老年人的血糖稳定,控制中老年人的体重,降低肥胖的发生率。     

行波磁场对RH精炼过程混合特性的影响

建立了RH精炼装置内混合行为的数学模型,考察了不同励磁电流参数下行波磁场对RH精炼装置内混合特性的影响.计算结果表明:混匀时间随电流强度的增大而减小,并且近似成线性关系;混匀时间随电流频率的增加先减小后增大,并且在30Hz时达到极小值;在励磁电流强度为200A,频率为10Hz的条件下,在上升管或下降管施加行波磁场混匀时间可缩短9%～17%;在相同操作条件下,在上升管处施加行波磁场混匀时间小于在下降管施加行波磁场的混匀时间;同时在上升管和下降管施加行波磁场,混匀时间可缩短18%～26%;混匀时间随吹氩量的增大而减小,在吹氩量为1600NL/min时混匀时间达到极小值,吹氩量继续增大时,混匀时间反而增大.     

葡萄糖还原Cu(Ⅱ)制备超细Cu_2O

研究了液相法中葡萄糖还原Cu(Ⅱ)制备Cu2O的反应条件及其优化,结果表明:影响Cu2O粒度和质量的主要因素依次为NaOH用量、反应温度、搅拌速度、反应时间和葡萄糖用量;在优化的反应条件下,制备了粒度小、粒度分布范围窄的超细Cu2O,即平均粒度D﹙v,0.5﹚为2.865μm、[D(v,0.9)-D(v,0.5)]为1.202μm的超细Cu2O.     

不同最大摄氧量间接测定法特点的初探

本文回顾总结了不同性别类型划分最大摄氧量间接测定方法的优劣势情况以及国内科研人员通过几种常用间接测定方法对不同人群最大摄氧量的测定情况,旨在协助科研人员针对不同运动项目运动员及适应人群选择合理的最大摄氧量试验方案提供科学理论依据.     

Hydrogen metabolic pathways of <Emphasis Type="Italic">Rhodospirillum rubrum</Emphasis> under artificial illumination

Multiple enzymes involved in hydrogen metabolism have been detected in photosynthetic bacterium Rhodospirillum rubrum un-der various growth conditions. To investigate hydrogen metabolic pathways and the contribution of each pathway to hydrogen photoproduction in R. rubrum under the artificial illumination condition, three mutants were constructed, including nifHanfDG double mutant lacking both Fe-nitrogenase and Mo-nitrogenase, anfDG mutant lacking Fe-nitrogenase and nifHhupL double mu-tant (uptake hydrogen...     

番茄红素对糖尿病小鼠血糖的影响

为探讨番茄红素对糖尿病小鼠的降血糖作用,实验采用腹腔注射四氧嘧啶复制糖尿病小鼠模型,随机分为5组:正常对照组、模型对照组、阳性对照组、番茄红素高剂量组(40 mg/kg)及番茄红素低剂量组(20mg/kg);并进行正常小鼠糖耐量实验,即对150只正常小鼠连续灌胃番茄素2周后,以葡萄糖氧化酶法测定其空腹血糖,结果表明:番茄红素对糖尿病小鼠的体重无显著影响,番茄红素高、低剂量组能显著降低糖尿病小鼠空腹血糖值;与模型组相比,番茄红素高、低剂量组对小鼠的糖耐量具有显著的增强作用(P(0.05),其效果随剂量增加而增强。这显示番茄红素对糖尿病小鼠有降血糖作用。     

不同外碳源对生物反硝化影响的研究

针对城镇污水处理中碳源不足影响系统脱氮能力的问题,分别以乙酸钠、葡萄糖、甲醇作为外源性碳源,考察各碳源对活性污泥脱氮能力的影响。研究结果表明,在乙酸钠投加量分别为50、100、200mg/L条件下,NO3--N去除率分别为68.8%、85.8%、100%;在葡萄糖投加量为50、100、200mg/L的条件下NO3--N去除率分别为47.3%、64.3%、76.2%;甲醇有一定的滞后性,在投加初期对反硝化能力并没有明显的促进作用。由试验结果可知,乙酸钠可以作为高效外源性碳源用作城镇污水脱氮除磷。     

高浓度葡萄糖促进人二倍体成纤维细胞迅速衰老

利用光学显微镜观察和酸性β-半乳糖苷酶染色技术研究了高浓度葡萄糖对人二倍体成纤维细胞2BS细胞衰老进程的影响,并用流式细胞仪检测了此过程中活性氧和线粒体膜电位差的变化。结果表明：200 mmol/L的葡萄糖对2BS细胞有生长抑制作用,能引起活性氧含量的变化,导致线粒体膜电位差显著下降,并诱导了细胞的衰老。这为氧化损伤假说提供了新的证据,并为研究活性氧和复制衰老之间的关系提供了较好的体系。     

模拟酶用于测定葡萄糖及免疫分析的研究

研究锰-四磺基苯卟啉(Mn-TPPS₄)络合物催化过氧化氢与邻苯二胺反应的特性,并与辣根过氧化物酶比较。与葡萄糖氧化酶的酶促反应偶联,测定血清中的葡萄糖,与试剂盒测定结果吻合。用两种方法将Mn-TPPS₄标记到牛血清白蛋白上,其免疫活性和催化活性均较好。