UHT产品三聚氰胺检测方法中前处理改进方法

研究TUHT产品三聚氰胺检测过程中前处理的检测方法,样品前处理利用透析纸或透析袋的热熔性和透析度,通过分子隔断筛选,使三聚氰胺分子自由穿入并溶于水中。此方法与国标方法比较：透析方法的前处理省时省事,并且所用消耗品较少,总体成本较现用方法便宜,但是在使用透析纸密封样品时必须小心包扎,不能漏样。     

6-姜烯酚诱导人结肠癌细胞HT29凋亡及与VEGFR2表达变化的关系

本文通过研究不同浓度6-姜烯酚诱导结肠癌细胞HT 29凋亡及与VEGFR2(血管内皮细胞受体2)不同表达之间的关系,以探讨其可能的抑制结直肠肿瘤相关机制。通过应用不同浓度6-姜烯酚(0、10、20和40μM)分别对体外细胞实验培养的HT29细胞株进行诱导处理24 h,相差倒置荧光显微镜观察细胞形态变化,CCK8(Cell Counting Kit-8)法测定药物诱导后细胞抑制率,Annexin V-FITC/PI流式细胞术检测不同浓度药物干预后细胞凋亡率及凋亡周期变化,最后用Western-blot检测分析VEGFR2蛋白不同表达变化。结果显示,与对照组相比,6-姜烯酚可呈浓度依赖性地诱导HT29凋亡,并使细胞周期G0/G1期细胞数由49.48%下降到24.39%和17.18%,而G2/M期细胞数由3.44%增加到34.78%和49.54%,进而将细胞周期阻滞在G2/M期,抑制细胞增殖,而且还不同程度地抑制了VEGFR2表达(p0.05)。结果表明,6-姜烯酚主要是通过诱导HT29凋亡进而起到抑制肿瘤细胞增殖的作用,这可能与不同程度抑制VEGFR2有关。     

肠道吸收细胞模型研究进展及其在类胡萝卜素上的应用

膳食化合物在维持人体生理功能和预防疾病等方面至关重要,但其必须被人体高效吸收利用才能充分发挥其功能活性。肠道吸收细胞模型已成为体外模拟人体膳食化合物吸收利用及机制研究的有效手段。针对不同的膳食化合物,选取合理的肠道细胞吸收模型以及在现有细胞模型的基础上进一步改进,对于实现高效模拟人体对该膳食化合物的吸收利用具有重要意义。因此,本文概述了人体肠道上皮细胞的结构和功能,系统地综述了体外肠道细胞吸收模型研究进展,并以类胡萝卜素为代表,阐述了其肠道吸收转运机制,重点探讨了Caco-2单细胞模型和Caco-2/HT29-MTX细胞共培养模型在其吸收利用上的应用,以期为更好地利用肠道细胞吸收模型体外模拟人体对不同膳食化合物的吸收利用提供借鉴。     

Efficiency above 6% in poly(3‐hexylthiophene):phenyl‐C‐butyric acid methyl ester photovoltaics via simultaneous addition of poly(3‐hexylthiophene) based grafted graphene nanosheets and hydrophobic block copolymers

A combination of reduced graphene oxide (rGO) nanosheets grafted with regioregular poly(3‐hexylthiophene) (P3HT) (rGO‐g‐P3HT) and P3HT‐b‐polystyrene (PS) block copolymers was utilized to modify the morphology of P3HT:[6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) active layers in photovoltaic devices. Efficiencies greater than 6% were acquired after a mild thermal annealing. To this end, the assembling of P3HT homopolymers and P3HT‐b‐PS block copolymers onto rGO‐g‐P3HT nanosheets was investigated, showing that the copolymers were assembled from the P3HT side onto the rGO‐g‐P3HT nanosheets. Assembling of P3HT‐b‐PS block copolymers onto the rGO‐g‐P3HT nanosheets developed the net hole and electron highways for charge transport, thereby in addition to photoluminescence quenching the charge mobility (μ_h and μ_e) values increased considerably. The best charge mobilities were acquired for the P3HT₅₀₀₀₀:PC71BM:rGO‐g‐P3HT₅₀₀₀₀:P3HT₇₀₀₀‐b‐PS₁₀₀₀ system (μ_h = 1.9 × 10^?5 cm² V^–1 s^–1 and μ_e = 0.8 × 10^?4 cm² V^–1 s^–1). Thermal annealing conducted at 120 °C also further increased the hole and electron mobilities to 9.8 × 10^?4 and 2.7 × 10^?3 cm² V^–1 s^–1, respectively. The thermal annealing acted as a driving force for better assembly of the P3HT‐b‐PS copolymers onto the rGO‐g‐P3HT nanosheets. This phenomenon improved the short circuit current density, fill factor, open circuit voltage and power conversion efficiency parameters from 11.13 mA cm^?2, 0.63 V, 62% and 4.35% to 12.98 mA cm^?2, 0.69 V, 68% and 6.09%, respectively. © 2019 Society of Chemical Industry     

Incoloy800HT管线断裂失效分析

针对Incoloy 800HT管线断裂,检查原始施工记录,并通过扫描电镜和金相,及其应力分析等手段.研究结果显示,断裂处的材料出现了沿晶界析出的σ相和蠕变空洞并导致材料脆化,接管悬挂过重加速了蠕变空洞的形成,是导致接管断裂的根本原因.     

A New HPLC-MS Method for Measuring Maslinic Acid and Oleanolic Acid in HT29 and HepG2 Human Cancer Cells

Maslinic acid (MA) and oleanolic acid (OA), the main triterpenic acids present in olive, have important properties for health and disease prevention. MA selectively inhibits cell proliferation of the HT29 human colon-cancer cell line by inducing selective apoptosis. For measuring the MA and OA concentration inside the cell and in the culture medium, a new HPLC-MS procedure has been developed. With this method, a determination of the amount of MA and OA incorporated into HT29 and HepG2 human cancer-cell lines incubated with different concentrations of MA corresponding to 50% growth inhibitory concentration (IC₅₀), IC_50/2, IC_50/4, and IC_50/8 has been made. The results demonstrate that this method is appropriate for determining the MA and OA concentration in different types of cultured cells and reveals the specific dynamics of entry of MA into HT29 and HepG2 cells.     

Effect of [6,6]‐phenyl‐C61‐butyric acid methyl ester on the morphology of poly(3‐hexylthiophene) film

The change of morphology of poly(3‐hexylthiophene) (P3HT) film as a result of blending with [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM) was studied using a freeze‐dry method. A porous structure was observed as the P3HT/PCBM solution was freeze‐dried. The pore size decreased as the proportion of PCBM increased in the P3HT/PCBM blended film. Additionally, the freeze‐dried P3HT/PCBM film was more resistant to the formation of PCBM crystals than that prepared by a spin‐coating method during the thermal annealing process. Homogeneous distribution of PCBM in the freeze‐dried P3HT/PCBM film was the main reason for the reduction of large PCBM crystal formation. Copyright © 2011 Society of Chemical Industry