乳化剂与面粉中大分子物质的相互作用及其应用

综合论述了乳化剂与面粉中食品大分子--淀粉、蛋白质、脂类化合物的相互作用,对作用原理进行了分析和论述;同时探讨了乳化剂在面制品中的应用,为乳化剂在面粉制品中的应用提供了一定的理论依据.  

Analysing the curriculum development process: three models

This article attempts to analyse the curriculum development process by using three models, i.e. the modern model, the postmodern model and the model suggested by the actor-network theory. It is argued that no matter what context we are in, curriculum is the manifestation of the power distribution in society. It is critical to note that power is not a fixed entity, but a strong network formed by heterogeneous components. Therefore, the study of change in this network formation can greatly enhance the analysis of curriculum.  

等离子体改性醋酯纤维的烟焦油吸附性能

采用低温常压等离子体对醋酯纤维进行表面改性处理,以提高其对烟焦油的吸附性能.为模拟人的吸烟过程,自行设计了一套烟焦油吸附装置.采用单因素和正交试验,研究了等离子体处理电压、时间、氩气流量和极板间距等因素对烟焦油吸附性能的影响.结果表明,等离子体改性处理的最优工艺为:电压180V,时间90s,氩气流量3L/min,极板间距3mm.采用优化工艺处理的醋酯纤维,对烟焦油的吸附量比常规醋酯纤维高41.73％.  

Comparative study of regulated and unregulated air pollutant emissions before and after conversion of automobiles from gasoline power to liquefied petroleum gas/gasoline dual-fuel retrofits

Liquefied petroleum gas (LPG) is increasingly being examined as an alternative to gasoline use in automobiles as interest grows in reducing air pollutant emissions. In this study, emissions of regulated (CO, THC, NO(x)) and unregulated air pollutants, including CO2, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and BTEX (acronym for benzene, toluene, ethylbenzene, xylene), were measured before and after conversion of nine gasoline-powered automobiles to LPG/ gasoline dual-fuel retrofits. The tests were conducted on a standard chassis dynamometer in accordance with the United States Environmental Protection Agency FTP-75 test procedure, with the exception that all tests were conducted under hot-start driving conditions. The influences of LPG on air pollutant emission levels and carcinogenic potency were investigated and compared with gasoline. The results showed average emission factors of 0.14 g/km, 0.33 mg/km, 0.09 g/km, 0.44 g/km, and 197 g/km for CO, THC, NO(x), PM, and CO2, respectively, for LPG/ gasoline dual-fuel retrofits. Paired-sample t-test results indicated that the emissions of CO (p = 0.03), THC (p = 0.04), and CO2 (p = 4.6 x 10(-8)) were significantly reduced with the retrofit in comparison with gasoline-powered automobiles. The reduction percentages were 71%, 89%, and 14% for CO, THC, and CO2, respectively. The average total PAH emission factor for LPG was 217 microg/km, which is significantly lower than gasoline (863 microg/km; p = 0.05). The PAH corresponding carcinogenicities (BaP(eq)) were calculated via toxic equivalencies based on benzo(a)pyrene (BaP). Paired-sample t-test results fortotal BaP(eq) emissions showed no significant difference between gasoline (30.0 microg/km) and LPG (24.8 microg/km) at a confidence level of 95%. The discrepancy between PAH and BaP(eq) emissions resulted from the higher emission percentages of high molecular weight PAHs for LPG, which might be from lubricant oil. The average emission factors of benzene, toluene, ethylbenzene, and xylene were 351, 4400, 324, and 1100 microg/ km, respectively, with LPG as fuel, which were all significantly lower than those for gasoline (95% confidence level). The average reduction percentages were 78%, 61%, 57%, and 58% for benzene, toluene, ethylbenzene, and xylene, respectively.  

叶酸对肌萎缩性侧索硬化症线虫TAR DNA结合蛋白43（TDP-43）毒性的改善作用

为探讨叶酸添加对TAR DNA结合蛋白43（TDP-43）毒性导致的肌萎缩性侧索硬化症（amyotrophic lateral sclerosis，ALS）治疗方面产生的作用，本文选用转入人TDP-43的转基因秀丽隐杆线虫作为受试生物，探究不同浓度叶酸（0.01 mmol/L、0.025 mmol/L 、0.05 mmol/L）干预对线虫的寿命、生殖能力、瘫痪率、头部摆动频率、捕食能力与学习记忆能力的影响。结果显示，与对照组相比，0.025 mmol/L组和0.05 mmol/L组线虫寿命分别提高了22.48%和11.92%；0.025 mmol/L组线虫的生殖能力增加了25.26%；0.01 mmol/L组和0.025 mmol/L组线虫的瘫痪率分别降低了20.19%与37.62%；0.025 mmol/L组线虫头部摆动频率在叶酸干预后的第2、4、6 d分别提高了17.14%、32.88%和39.18%；三个干预组线虫的捕食能力分别提高了24.58%、60.30%和15.85%，学习记忆能力也分别提高了36.84%、57.89%和31.58%，上述结果均具有统计学差异（p<0.05）。而且，与0.01 mmol/L组和0.05 mmol/L组比较，0.025 mmol/L组线虫的瘫痪率显著下降，其他指标均显著增加，差异有统计学意义（p<0.05）。以上结果表明，叶酸添加改善了ALS线虫中hTDP-43蛋白引起的毒性效应，并且0.025 mmol/L浓度的叶酸可能是ALS线虫最佳的干预剂量。