Comparison of attrition in citric acid modified soybean hulls and commercial cation exchange resins

The integrity of ion exchange media used under conditions of different times of use, temperatures and pH values is important in its selection. This study was conducted to quantify the lack of integrity (attrition) in base-extracted (BE), citric acid (CA)-modified soybean hulls, a lignocellulosic cation exchange material and compare its attrition to two synthetic, commercial cation exchange resins. Attrition was determined in both batch and column operations. Batch studies included measuring attrition over a 24 h period under conditions of constant pH, variable pH and at different temperatures. Under conditions of a constant pH of 4.8, 25°C and using a stir bar, modified hulls had mostly lower attrition than the two commercial products. Under acidic conditions, modified hulls demonstrated very low (<5%) attrition. At alkaline pH values, modified hulls had higher attrition than the resins after 24 h of stirring at 25°C. Although attrition increased at alkaline pH, the modified hulls ability to bind copper ion (Cu²⁺) was unaffected by pH. After 24 h shaking at 65 and 85°C, modified hulls also had greater attrition than the synthetic polymers. At these temperatures, a decreased ability of the modified hulls to bind copper ion was observed compared to the lower temperatures of 25 and 45°C. When the products were compared in column experiments at 25°C, all materials had low (<10%) attrition. Our studies indicate that in terms of product integrity, modified soybean hulls could be useful in several applications requiring a metal ion adsorbent, but not necessarily at high temperatures.     

Wheat Superoxide Dismutase Isoenzymes

Evidence was obtained indicating that the superoxide dismutase (SOD) A and B isoenzymes of the wheat cultivar Tonic are of the Cu/Zn type, whereas the SOD–C group are similar to manganese containing dismutases. Heat inactivation plots showed that the enzymic activity in crude extracts was relatively stable up to 50°C. The thermodynamic parameters enthalpy, ΔH#, free energy, ΔG#, and entropy, ΔS#, were estimated for the thermal inactivation of extracted SOD activity and a purified SOD–C isoenzyme. The SOD-C isoenzyme was purified extensively and shown to contain two closely related tetrametic isozymes (pI6·0 and 6·1) ofM_r80 000. AM_rof 20 000 has been calculated for the subunits. TheN-terminal amino acid sequence of the purified SOD–C could be aligned with that of the Mn–SOD enzyme of maize and showed 57% homology.     

20周太极拳练习对青少年身体机能和身体素质影响的研究*

针对近年来青少年身体机能和身体素质不断下降的问题，运用横向组间对比和纵向组内对比的实验设计，分别在实验前、实验中（第10周）、实验后（20周）进行三次测试，选取安静心率、肺活量、50m跑、立定跳远、坐位体前屈、一分钟仰卧起坐等指标，研究20周规律的太极拳锻炼是否能够改善青少年相关身体测试指标。研究结果显示，女生实验组安静心率在第10周出现显著性降低、其他指标男女实验组均在第20周出现显著性改善。研究结果表明20周的规律太极拳锻炼可以改善青少年身体机能和身体素质指标。     

Single and mixture toxicity of gold nanoparticles and gold(III) to Enchytraeus buchholzi (Oligochaeta)

The ecotoxicity of gold nanoparticles (Au-NPs), gold(III) and their mixtures was assessed in the potworm Enchytraeus buchholzi after 14-day bioassays. The worms were exposed at 20 °C in OECD artificial soil to 0, 9.37, 18.7, 28.1 and 37.5 mg/kg Au-NPs or Au(III) and 0, 9.37 + 9.37, 18.7 + 18.7, 28.1 + 28.1, 37.5 + 37.5 mg Au-NPs + Au(III)/kg. The results indicated that the range of Au-NPs concentrations used in the present study was not deleterious to the survival and reproduction of E. buchholzi. Au(III) showed no significant effect on survival but was significantly deleterious to reproduction in the highest treatment (p ≤ 0.01). A 14-day EC50_Au(III) = 35.5 mg/kg was estimated for effects on reproduction. Au-NPs/Au(III) mixtures essentially caused the same effects as Au(III) except for 18.7 mg Au(III)/kg vs. 18.7 + 18.7 mg Au-NPs + Au(III)/kg where the mixture treatment was significantly more toxic to reproduction (p < 0.02). Mixture results suggested a seemingly additive effect between Au-NPs and Au(III), although the conventional toxic unit approach could not be used to ascertain this conclusively because of the lack of Au-NPs toxicity. The order of toxicity between Au-NPs, Au(III) and their mixtures was Au-NPs = Au(III) = Au-NPs/Au(III) for survival and Au-NPs < Au(III) ≤ Au-NPs/Au(III) for reproduction.     

血糖仪快速测定豆类中葡萄糖含量方法

目的：应用血糖仪快速测定黑豆、黄豆、红豆、绿豆中的葡萄糖含量。方法：豆子加水匀浆后，离心收集上清液，用血糖仪测定4种豆类中的葡萄糖含量。结果：红豆葡萄糖含量为（6.02±0.19）mg/g、绿豆葡萄糖含量为（3.56±0.22）mg/g，黑豆葡萄糖含量为（2.11±0.12）mg/g、黄豆葡萄糖含量为（1.34±0.07）mg/g。结论：血糖仪法可快速简便测定豆类中的葡萄糖含量，4种豆中葡萄糖含量差异显著，从大到小依次为红豆〉绿豆〉黑豆〉黄豆。     

蛛网图评价法在机械设备外观设计决策中的应用

针对机械设备外观设计如何决策的问题,提出将蛛网图评价法应用于外观设计方案的对比中,以辅助设计决策,并通过实例进行验证,旨在为机械设备外观设计决策提供参考.     

高校图书馆用户信息需求特点分析与信息服务对策

分析高校各种不同用户群体对信息需求的特点,探讨提高高校图书馆信息建设与信息服务质量的对策。     

人癌症/睾丸相关蛋白XAGE-1b原核表达载体的构建及融合蛋白的表达

目的构建人癌症/睾丸相关蛋白XAGE-1b原核表达载体及诱导XAGE-1融合蛋白表达。方法从文库质粒pACT2-XAGE-1b中利用PCR法扩增XAGE-b cDNA编码序列,将其克隆到pET-32a载体中,并将重组质粒pET-32bXAGE-1b转染大肠杆菌DE3中,用异丙基硫代半乳糖苷（IPTG）诱导表达,Western blot检测融合蛋白表达。结果原核表达载体pET-32a-XAGE-1b构建成功;转染菌株经IPTG诱导后,出现约29 kD蛋白过表达,Western-blot检测显示His6融合蛋白表达。结论成功构建原核表达载体pET-32a-XAGE-1b,转染菌株可表达His6融合蛋白。     

Pokemon敲减对结肠癌Lovo细胞周期、迁移和侵袭能力的影响

目的观察Pokemon敲减对结肠癌Lovo细胞周期、迁移和侵袭能力的影响。方法转染shRNA质粒构建Pokemon敲减的稳定细胞株Lovo-KD和阴性对照细胞株Lovo-NC,用荧光定量PCR检测Pokemon基因敲减效率,流式细胞术检测细胞周期变化,Transwell实验观察细胞迁移和侵袭能力。结果与Lovo-NC细胞比较,Lovo-KD细胞Pokemon mRNA水平下降65.0%（P〈0.01）,G1期细胞比例升高[（56.7±0.8）%vs（26.7±1.6）%,P〈0.01],迁移细胞数[（8±4）vs（189±19）个/视野,P〈0.01]和侵袭细胞数[（6±3）vs（183±13）个/视野,P〈0.01]减少。结论 Pokemon基因敲减可将Lovo细胞阻滞于G1期,使细胞迁移和侵袭能力显著下降。     

A method of power measurement under nonsinusoidal periodic signals

In power system,traditional method of nonsinusoidal power measurement is not feasible for containing non integer harmonics condition. A method of power measurement based on Prony algorithm is presented. At first, identify all modes of integer and non interger harmonics from voltage and current signals, using Prony method. Futher more, calculate active and reactive power in each harmonics frequency, using the modes of harmonics. Based on the defination of IEEE active power, a expression of Budeanu power is given in non integer harmonics condition. At last, active and reactive power of energy gird are calculated. The results of simulation prove that this method is feasibility. The method of power measurement based on Prony algorithm has high precision, especially for non integer harmonics condition.