Anti-adipogenic effects of extracts of Ficus deitoidea var. deltoidea and var. angustifolia on 3T3-L1 adipocytes

Objective： This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes. Methods： Methanol and water extracts of leaves of the F. deltoidea varieties were analyzed to determine their total flavonoid content （TFC） and total phenolic content （TPC）, respectively. The study was initiated by determining the maximum non-toxic dose （MNTD） of the methanol and water extracts for 3T3-L1 preadipocytes. Possible anti-adipogenic effects were then examined by treating 2-d post confluent 3T3-L1 preadipocytes with either methanol extract or water extract at MNTD and half MNTD （1/2MNTD）, after which the preadipocytces were induced to form mature adipocytes. Visualisation and quantification of lipid content in mature adipocytes were carried out through oil red O staining and measurement of optical density （OD） at 520 nm, respec- tively. Results： The TFCs of the methanol extracts were 1.36 and 1.97 g quercetin equivalents （QE）/100 g dry weight （DW）, while the TPCs of the water extracts were 5.61 and 2.73 g gallic acid equivalents （GAE）/100 g DW for var. deltoidea and var. angustilofia, respectively. The MNTDs determined for methanol and water extracts were （300.0±28.3） and （225.0±21.2） μg/ml, respectively, for var. deltoidea, while much lower MNTDs [（60.0±2.0） IJg/ml for methanol extracts and （8.0＋1.0） μg/ml for water extracts] were recorded for var. angustifolia. Studies revealed that the methanol extracts of both varieties and the water extracts of var. angustifolia at either MNTD or 1/2MNTD significantly inhibited the maturation of preadipocytes. Conclusions： The inhibition of the formation of mature adipocytes indicated that leaf extracts of F. deltoidea could have potential anti-obesity effects.     

Separation of dichloromethane-nitrogen mixtures by adsorption: experimental and molecular simulation studies

Experimental and grand canonical Monte Carlo simulation results for the separation of a CH²C1² (1.5 mol%)-N₂ binary gas mixture in molecular sieve materials are presented. AlPO₄-5 and MCM-41 molecular sieves have been used as the selective adsorbents because they consist of uniform arrays of uni-dimensional channels of micro and meso length scales, respectively. Adsorption isotherms were measured at 318 K and at pressures between 50 kPa and 130 kPa. Two MCM-41 materials have been used, one with a 33 A pore diameter and the other with a 42 Á pore diameter. For AlPO₄-5 at 110kPa the total amount adsorbed from experiment was found to be independent of equilibration time at 0.0542, 0.0538 and 0.0547 mmol per g AlPO₄-5 for 2, 24 and 48 hours, respectively. However, the selectivity for CH₂C1₂ was found to increase with time from 1.29, to 4.59, to 10.74. For MCM-41 at 110kPa the selectivity for CH₂C1₂ was found to be dependent on pore size. On increasing the pore size from 33 Å to 42 Á the selectivity for CH₂C1₂ increased considerably. Grand canonical Monte Carlo simulations agreed qualitatively with the experimental results, showing a greater selectivity for CH₂C1₂ than for N₂. The simulations indicate that MCM-41 has a lower selectivity for CH₂C1₂ than A1PO₄-5, which contradicts the experimental results. Reasons for these discrepancies are presented and discussed.     

基于矩量法的三维导体目标散射问题的研究

将CAD(computer aided design)建模与矩量法相结合并应用于三维导体目标散射问题的研究.在CAD建模的基础上,得到了符合电磁计算要求的几何数据,并以此为基础计算得到表面电流,散射场等电磁参数.分析了非奇异积分的数值解及奇异积分的解析解,指出了奇异积分出现的具体条件,给出了几种典型三维导体结构的雷达反射截面(radar cross section,RCS),平面天线输入阻抗与经典理论计算进行了比较.仿真结果表明,CAD建模与矩量法相结合的算法对于计算三维导体散射场,RCS等相关电磁特性具有广泛的适用性及准确性.