IN VITRO ANTIOXIDANT AND ANTICANCER ACTIVITIES OF EXTRACTS FROM A FERMENTED FOOD

Solvent extracts were prepared from Manda Enzyme®, one of the fermented health foods, and their activities of radical scavenging and cancer cell growth inhibition were evaluated. Manda Enzyme® was extracted with 55% ethanol, and then fractionated into n‐hexane, chloroform, ethyl acetate, methanol‐soluble and methanol‐insoluble fractions. The antioxidant activities were in the order chloroform > ethyl acetate > other fractions and of each fraction were positively related to the amount of total phenolics and the intensity of brown color. The cancer cell growth inhibitory activities were in the order n‐hexane > chloroform > other fractions. Proliferation of HRT‐18, HCT‐48 and HepG2 human cancer cells was inhibited by the treatment of the n‐hexane fraction of Manda Enzyme® at a concentration of 400 μg/mL to the extent of 75, 89 and 90%, respectively. From these results, it is considered that Manda Enzyme® has chemically different ingredients showing strong antioxidant and anticancer activity in vitro.     

蜂窝状筛网催化剂上NH_3选择性催化还原NO的工艺特性

采用蜂窝状筛网催化剂进行NH3选择性催化还原NO的反应 ,考察了温度、空速、进料比及进料气、氧、水含量等因素对其催化性能的影响。结果表明 :进料气含量和进料比的增加均可提高NO的转化率 ;体积分数 2 %的氧便可封闭催化循环 ,显著提高NO转化率 ;当水体积分数在 2 %以内时 ,水的添加将导致NO转化率的降低。蜂窝状筛网催化剂与蜂窝状堇青石催化剂相比 ,具有优异的非稳态响应特性 ,反应可在较短的时间内进入稳态     

聚合物降解产物伤害与糖甙键特异酶破胶技术

综述了钻井，完井，尤其是水力压裂作业中产生的多糖类聚合物伤害和应用糖甙键特异酶破胶，解除多糖类聚合物伤害的技术。第一节报道了聚合物降解产物造成的伤害，指出冻胶破胶液粘度低并不代表压裂液已从充填裂缝中充分返排，氧化破胶剂和普通酶破胶剂不能使多糖类聚合物充分降解，产生的大分子量，水不溶的降解产物可对地层造成伤害，消除伤害的办法是采用对糖甙键有特异性的各种水解酶作压裂液破胶剂或伤害地层处理剂。第二节报道了各种聚合物（纤维素，瓜尔胶，淀粉）糖甙键特异酶降解聚合物的机理。第三节报道了糖甙键特异酶（主要针对瓜尔胶）的应用性能测试及结果，包括岩心流动实验，含糖量和分子量测定，传导性测试。第四节介绍了糖甙键特异酶消除聚合物伤害和用作压裂液破胶剂的现场应用，包括选井原则，实施工艺要点及3个典型井例。     

Heat Denaturation and Emulsifying Properties of Egg Yolk Phosvitin

Phosvitin in water at pH 7 had a denaturation temperature (T_d) of 79.7 ± 1.4°C when heated at 10°C/min. When dissolved in 0.1M and 1.0M NaCl, the T_d decreased to 77.7 ± 1.2°C and 77.2 ± 1.3°C, resoectivelv. and in 10 and 20% sucrose there was no change in T_d. Heat treatment of phosvitin solutions at ≥65°C led to decreased emulsifying activity (EA). The emulsion stability (ES) decreased when phosvitim solutioni were heated at 70, 80 or 96°C for up to 60 min. The ES was not affected (p < 0.05) for phosvitin solutions after heating at ≤67.5°C for up to 60 min.     

Cooked Blue Crab Claw Meat Aroma Compared with Lump Meat

Sensory evaluation of claw and lump crabmeats by sniffing indicated no aroma difference (p > 0.05); however, differences (p < 0.05) were found between the taste and aromatics of aqueous extracts of both meats. Eleven aroma notes (combined total) were found in the meats by aroma extract dilution analysis (AEDA). Flavor dilution factors for compounds common to both meats were not statistically different (p > 0.05). Aroma notes found to have highest intensity in both meats were: meaty/salty/soy sauce [3-(methylthio)-propanal], sweet/fruity, metallic/rubber/gasoline, nutty/popcorn [2-acetyl-l-pyrroline], nutty/popcorn, pine/sweet/hay/dry seaweed, and mushroom/solvent.     

NONENZYMATIC BROWNING IN DRIED RED PEPPER PRODUCTS

The nonenzymatic browning of dried red peppers was studied under various water activities, storage temperatures, and packaging atmospheres. Whole pepper and pepper powders-coarse and fine, with and without seeds-were compared. The browning can be described by the zero order reaction, and the rate constant is strongly affected by water activity and temperature. Flushing the package with nitrogen did not have a significant effect on the browning rate. For minimum browning, the peppers should be stored at water activities below 0.3 and in the form of whole pods or coarse powder with seeds.     

Physical measures of sensory texture in thawed sea scallop meat

An instrumental method of texture measurement for scallop (Placopecten magellanicus) meats after frozen storage has been developed to replace the sensory method. Non-destructive and destructive compressive forces at 50 and 80% deformation respectively and shear peak force gave significant correlation coefficients of 0.89, 0.78 and 0.82 respectively with sensory evaluation of the cooked meats. The coefficient of variation associated with the compression method was smaller, however, than with the shear method.     

Relationships Between Physicochemical Properties of Nonfish Protein and Textural Properties of Protein-incorporated Surimi Gel

The physicochemical properties of nonfish proteins were correlated with textural properties of nonfish protein gels and nonfish protein-incorporated surimi gels. Both cold and thermal hydration ability (by centrifugation) of nonfish proteins strongly correlated with compressive force (cohesiveness) of nonfish protein-incorporated surimi gel (r = 0.94 for cold; r = 0.95 for thermal). Hydrophobic amino acid groups in nonfish protein inversely correlated with compressive force (r =?0.88) and penetration force (r =?0.78) of nonfish protein-incorporated surimi gel. Thermal behavior of nonfish protein affected the gel characteristics of nonfish protein and surimi with nonfish protein-incorporated.     

大脑快速 T1 图谱成像研究

大脑快速 T1图谱成像是一种量化磁共振成像技术,可以为帕金森、癫痫、肝脑病等脑部疾病的诊断提供重要参考依据。现有的大脑快速 T1图谱成像技术可以将成像速度提高到几秒/层,然而主磁场、发射场的不均性(尤其在高场下)以及大脑内部结构的磁化率差异,降低了成像精确性,限制了其在临床上的推广应用。针对上述缺点,文章提出一种基于 TurboFLASH技术的大脑快速 T1图谱成像方法,并先后在计算机仿真实验、仿体以及人体试验中进行验证。实验结果表明,文章提出的方法测得的大脑组织 T1值与金标准及文献中报导的值非常接近(误差＜3%),同时扫描速度提高到3秒/层,空间分辨率为1.1 mm×1.1 mm×4 mm,2分钟内即可完成全脑采集。