迷迭香提取物对高脂高胆固醇膳食仓鼠的保护作用研究

研究迷迭香提取物对高脂高胆固醇膳食致仓鼠高血脂症及氧化应激损伤的保护作用。50只仓鼠随机分为五组,分别为正常组、模型组和迷迭香膳食干预组(0.1%、0.3%及0.9%迷迭香提取物),测定血清中TC、TG和HDL-C水平、抗氧化酶活性和氧化产物MDA含量,脑及肝脏中抗氧化酶活力及氧化产物含量。血脂测定结果显示,模型组TC、TG水平较正常组显著升高,给予迷迭香提取物后,0.3%、0.9%剂量组组仓鼠TG水平降低(P0.05),HDL-C水平升高(P0.01);血清、肝脏和脑中抗氧化酶活测定结果显示,模型组抗氧化酶活性较正常组降低,氧化产物MDA含量较正常组显著升高。给予迷迭香提取物膳食干预后,血清及肝脏中SOD、CAT、GSH-Px酶活力较模型组升高,MDA含量较模型组组降低。因此迷迭香不仅可以直接调控高脂高脂胆固醇膳食仓鼠血脂水平,还可以减轻高脂高胆固醇诱导仓鼠造成的氧化损伤,从而保护机体。     

基于半固态发酵的红枣白兰地产品研制

为提高南疆红枣利用率,课题以南疆骏枣为原料,采用原料酶解预处理技术,并结合半固态发酵工艺,研究并建立了红枣白兰地的最佳生产工艺。试验结果表明原料处理最佳酶解条件为:在果胶酶和纤维素酶混合质量比为1∶3,添加量为0.75 g/kg,在pH为3.5,50℃条件下酶解3 h,红枣可溶性固形物含量最高;红枣白兰地最优生产工艺为发酵过程中接种SY型葡萄酒酵母0.3 g/kg,红枣料水质量比为1∶7,发酵温度为24℃,发酵时间为15 d,蒸馏出的白兰地产品酒精度为45%vol,所得产品具有枣香浓郁、口感醇厚,色泽清亮,风味独特等特点。     

响应曲面法优化TEMPO诱导氧化预处理工艺制备NFC

采用响应曲面法的Box-Behnken实验设计,考察TEMPO诱导氧化预处理工艺中,TEMPO、NaBr、NaC1O的用量对氧化反应时间和氧化程度(NaOH的消耗量)的影响.研究结果表明:随着TEMPO和NaBr用量增加,氧化反应速率加快,反应时间缩短,氧化程度略有减小;随着NaC1O的用量增加,氧化反应时间延长,氧化程度与之成线性增加趋势.通过Design-Expert软件在预设目标值的前提下,依据回归模拟方程优化得到了最佳的工艺条件:TEMPO用量0.024 mmol·g-1、NaBr用量2.50 mmol·g-1、NaC1O用量7.13 mmol·g-1,在此条件下进行了验证实验,其反应时间为56.76 min,NaOH的消耗量为35.05 mL,与回归方程的预测值非常接近.在优化的工艺条件下,对纤维素进行了TEMPO氧化预处理,然后进行机械法研磨,最终制备得到了纳米纤化纤维素(NFC).     

不同品种紫甘薯花青素熟化稳定性的研究

紫甘薯块根中含有丰富的花青素,花青素是被认可的抗氧化物质,在紫甘薯的熟化过程中会损失一些花青素。以15个紫甘薯品种为材料,采用可见分光光度法测定不同紫甘薯品种生粉的花青素含量和熟粉的花青素含量,旨在筛选花青素含量高且熟化加工后花青素减少量较小的的紫甘薯品种。结果显示,不同品种紫甘薯生粉、熟粉的花青素含量差异较大,熟化后不同品种花青素减少量差异显著。花青素含量高且熟化后花青素减少量较少的品种为紫罗兰、泰中11号和冀紫薯1号。     

Urinary concentrations of benzophenone-type UV filters in U.S. women and their association with endometriosis

Benzophenone (BP)-type UV filters are widely used in a variety of personal care products for the protection of skin and hair from UV irradiation. Despite the estrogenic potencies of BP derivatives, few studies have examined the occurrence of these compounds in human matrices. Furthermore, associations among exposure to these compounds and estrogen-dependent diseases (such as endometriosis) have not been examined previously. In this study, we determined the concentrations of five BP derivatives, 2-hydroxy-4-methoxybenzophenone (2OH-4MeO-BP), 2,4-dihydroxybenzophenone (2,4OH-BP), 2,2'-dihydroxy-4-methoxybenzophenone (2,2'OH-4MeO-BP), 2,2',4,4'-tetrahydroxybenzophenone (2,2',4,4'OH-BP), and 4-hydroxybenzophenone (4OH-BP), in urine collected from 625 women in Utah and California, using liquid chromatography (LC)-tandem mass spectrometry (MS/MS). The association of urinary concentrations of BP derivatives with an increase in the odds of a diagnosis of endometriosis was examined in 600 women who underwent laparoscopy/laparotomy (n = 473: operative cohort) or pelvic magnetic resonance imaging (n = 127: population cohort), during 2007-2009. 2OH-4MeO-BP, 2,4OH-BP, and 4OH-BP respectively were detected in 99.0%, 93.3%, and 83.8% of the urine samples analyzed, whereas the detection rates for 2,2',4,4'OH-BP and 2,2'OH-4MeO-BP were below 6.0%. Significant regional differences (higher concentrations in California) and monthly variations (higher concentrations in July and August) were found for urinary concentrations of 2OH-4MeO-BP and 2,4OH-BP. In addition, urinary concentrations of 2OH-4MeO-BP and 2,4OH-BP tended to be higher in more affluent, older, and leaner women. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for the urinary concentrations of BP derivatives and the odds of an endometriosis diagnosis; ORs increased across quartiles of 2OH-4MeO-BP and 2,4OH-BP concentrations, but a significant trend was observed only between 2,4OH-BP and the odds of an endometriosis diagnosis in the operative cohort (OR = 1.19; 95% CI = 1.01, 1.41). When women in the highest quartile of 2,4OH-BP concentrations were compared with women in the first three quartiles, the OR increased considerably (OR = 1.65; 95% CI = 1.07, 2.53). Given that 2,4OH-BP possesses an estrogenic activity higher than that of 2OH-4MeO-BP, our results invite the speculation that exposure to elevated 2,4OH-BP levels may be associated with endometriosis.     

Predicting beef tenderness using color and multispectral image texture features

The objective of this study was to investigate the usefulness of raw meat surface characteristics (texture) in predicting cooked beef tenderness. Color and multispectral texture features, including 4 different wavelengths and 217 image texture features, were extracted from 2 laboratory-based multispectral camera imaging systems. Steaks were segregated into tough and tender classification groups based on Warner-Bratzler shear force. The texture features were submitted to STEPWISE multiple regression and support vector machine (SVM) analyses to establish prediction models for beef tenderness. A subsample (80%) of tender or tough classified steaks were used to train models which were then validated on the remaining (20%) test steaks. For color images, the SVM model correctly identified tender steaks with 100% accurately while the STEPWISE equation identified 94.9% of the tender steaks correctly. For multispectral images, the SVM model predicted 91% and STEPWISE predicted 87% average accuracy of beef tender.     

大孔吸附树脂对绞股蓝多糖的吸附

研究了大孔吸附树脂对绞股蓝多糖的吸附热力学和动力学特征。采用紫外可见分光光度法测定了不同温度下的吸附等温线和吸附动力学曲线。结果表明:吸附平衡数据符合Langmuir方程、二级动力学模型、Boyd液膜扩散方程和Kannan-Sundaram颗粒内扩散方程,相关性均良好。该吸附过程为熵增加的非自发的吸热过程。吸附速率主要由颗粒内扩散控制。     

乙醇溶液中Tweens对猪胰脂酶的修饰作用

采用Tween系列表面活性剂在乙醇-水溶液体系中对猪胰脂酶进行修饰,以它们催化酯交换的交换量为指标评价修饰的效果,并且对修饰酶与未修饰酶的热稳定性进行了研究。结果表明:40℃下30 min即可完成Tweens对猪胰脂酶的修饰,但不同Tween的最佳条件并不相同。Tween 20修饰脂肪酶的最佳条件是无水乙醇与水的比例为1∶2(v/v),Tween 20用量为5%;Tween 40和Tween 65修饰猪胰脂酶的最佳条件是无水乙醇与水的比例为1∶2(v/v),用量均为15%;Tween 60修饰猪胰脂酶的最佳条件为无水乙醇与水的比例为1∶2(v/v),用量为20%;Tween 80修饰脂肪酶的最佳条件是无水乙醇与水的比例为1∶3(v/v),用量为5%;Tween 85修饰脂肪酶的最佳条件是无水乙醇与水的比例为1∶3(v/v),用量为15%。修饰后酶的热稳定性实验研究表明,在40～80℃间,修饰酶的催化反活性都高于未修饰酶。Tweens修饰猪胰脂酶能有效提高酶的活性及其热稳定性。     

绿色经济与我国纺织产业国际竞争力的提升

阐述绿色经济与提升我国纺织产业国际竞争力之间的关系。分析了清洁生产投入对节能减排效果和产业国际竞争力的作用机理;以纺织业为实证对象,验证了清洁生产对纺织产业国际竞争力的作用。指出:以清洁生产为主的环境保护投资对产业国际竞争力的影响是积极的,发展绿色经济给提升传统纺织产业国际竞争力带来机遇。认为:实施清洁生产可以通过技术变革和治污减排两个作用机制提升我国纺织产业国际竞争力。     

不锈钢长丝嵌织密度对织物屏蔽效能的影响

探讨棉不锈钢长丝合股纱嵌织密度及电磁波辐射角度对棉不锈钢长丝嵌织织物屏蔽效果的影响。测试了不同棉不锈钢长丝合股纱纬密及不同电磁波入射角度条件下织物的屏蔽效果。测试结果表明:织物屏蔽效能随着棉不锈钢长丝合股纱嵌织密度的增大而增大,在达到临界值后基本稳定不变;织物电磁透过率随着电磁入射角度的变化呈余弦平方曲线变化。指出:实际生产中,在保证织物屏蔽效果的基础上,应合理选择金属纤维纱线嵌织密度以节省原料;尽量在织物经纬向都加入金属纤维纱线以达到理想的屏蔽效果。