己糖转运蛋白在酿酒酵母生长与酒精发酵中的作用

酿酒酵母(Saccharomyces cerevisiae)的生长和发酵与其己糖转运蛋白家族紧密相关.酵母己糖转运蛋白家族包括Hxtlp至Hxt17p、Ga12p、以及同源蛋白Snf3p和Rgt2p这两个葡萄糖感应器.其中Hxt1p～Hxt7p对酵母生长及发酵发挥重要作用,缺失这7个蛋白的酵母无法从培养基中摄取己糖进行生长和发酵.根据对己糖的亲和力的不同,这几个转运蛋白可分为低亲和力转运子.包括Hxt1P和Hxt3p;高亲和力转运子,包括Hxt6p和Hxt7p;以及中等亲和力转运子Hxt2p和Hxt4p;而Hxt5p在生长发酵过程中没有发现有任何诱导表达.本文介绍了Hxt1p-Hxt7p等己糖转运蛋白在酵母生长发酵不同阶段中所发挥的作用,以期为构建高乙醇发酵效率的工业酵母菌株提供参考.     

铝包钢地线耐张线夹处断裂掉线事故分析及预防

为查清连续两次铝包钢地线耐张线夹处断裂掉线事故原因,对断裂耐张线夹样本进行试验分析。结果表明该耐张线夹断裂的原因是在线路施工过程中,未对线夹流板侧钢锚位置铝管部分进行压接,致使地线在长期运行过程中在钢锚出口位置产生疲劳载荷而部分断股,最终剩余钢丝承载力小于地线运行张力而段落掉线。对铝包钢地线耐张线夹压接施工管理、验收及运行提出建议。     

磷、铝交替作用下荞麦的叶绿素荧光特性变化

采用水培法,以不同耐铝品种江西荞麦(耐性)和内蒙荞麦(敏感)为材料,研究磷、铝交替处理下荞麦叶面积、叶绿素含量和叶绿素荧光参数的变化。结果表明,200μmol.L-1铝胁迫下,两品种荞麦的叶面积减小,叶绿素a(Chl a)、总叶绿素(Chl T)含量降低,最大荧光(Fm)和电子传递速率(ETR)下降,内蒙荞麦叶片初始荧光(Fo)显著升高,PSⅡ(PhotosystemⅡ)最大光化学效率(Fv/Fm)降低,江西荞麦Fo和Fv/Fm变化均不显著。磷、铝交替处理下,两品种荞麦的Chl a和Chl T含量较单铝处理组显著升高,Fv/Fm值略上升,Fo值降低,其中内蒙荞麦Fo下降显著,两品种荞麦叶片的Fm和ETR值有不同程度上升。说明磷处理能部分削弱铝毒对光合作用的光抑制和对光合机构的损伤,有利于植株光合作用的进行。     

浅议武术课在培养大学生耐挫折能力中的作用

中华武术是以传统哲学为理论基础,且作为高校体育课的重要组成部分对提高大学生的心理素质起到了重要作用。文章针对当代部分大学生心理承受能力较差,经不起挫折这一事实,阐述了高校武术课对培养大学生耐挫折能力的促进作用,并提出如何在高校教育中更好地开展武术课来提高学生的抗挫折能力,从而使他们保持健康的情绪。     

电磁搅拌器在铝熔炼过程中的应用及效果

介绍电磁搅拌器的结构组成、工作原理和工作方式,以及在铝熔炼过程中的应用及效果。     

河套蜜瓜的耐贮性对贮藏和运输的要求

河套蜜瓜属于厚皮甜瓜的早熟品种,采后乙烯的释放和呼吸强度均有跃变,因此不耐长期贮藏。但河套蜜瓜深受消费者喜爱,而且它的收获季节正值全国厚皮甜瓜的市场淡季。所以,搞好河套蜜瓜的运输和短期贮藏,对于其在全国形成大流通,添补市场空白,促进河套蜜瓜这一内蒙古特产的大力发展有十分重要的意义。     

高强板材在车身制造过程中的碰撞性试验研究

以某汽车侧碰中的主要承载和吸能部件帽形加强板为例,通过引入成形因素前后仿真结果的对比分析,研究了成形工艺引起的厚度变化和残余应变对其碰撞性能的影响,并与平均碰撞力的经验公式及试验结果进行了对比。结果表明,在汽车结构碰撞仿真中应考虑成形工艺因素引起的影响,厚度不均与塑性硬化均不可忽略,以提高碰撞分析的精度,得到更为符合实际情况的模拟结果。     

普通锯床在铝母线加工中的技术改进

文章主要论述了如何针对普通锯床在铝母线加工过程中所存的技术缺陷,对锯床进行相应的技术改进.实践证明改进后的据床工作效率与质量均有提高.     

铜铝双金属复合材料在幕墙行业中的应用

随着我国工业技术的快速发展,铜铝双金属复合材料逐渐成为幕墙行业中的关注焦点。铜铝双金属复合材料,既具备了铜材的高导电、导热率等性能,更兼具了铝材的质轻、耐腐蚀、经济美观的优点。将铜铝双金属复合材料应用于幕墙设计之中,有利于增强幕墙结构的稳定性、科技性、美观性、形体可塑造性等。文章以铜铝双金属复合材料为案例,分析其优化思路及提出加强对铜铝复合材料的结构布置、重视幕墙结构设计的一体化、明确金属复合材料的施工要点等幕墙使用方法,以期为我国工业设计及建筑装饰行业提供一定参考。     

形成性评价在高三英语复习中的重要作用

形成性评价的目的是激励学生学习,帮助学生有效地调控自己的学习过程,使学生获得成就感,增强自信心,培养合作精神。通过实践,＂形成性评价＂是有效的。     

Abdominal Obesity Associated with Elevated Serum Butyrylcholinesterase Activity,Insulin Resistance and Reduced High Density Lipoprotein-Cholesterol Levels

Abdominal obesity (AO) has a strong correlation with cardiovascular disease and has been linked to Alzheimer’s disease and type 2 diabetes. We investigated the association between AO and elevated serum butyrylcholinesterase (BChE) activity, insulin resistance and the serum lipid profile, including triglyceride (TG), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) levels in AO and non-AO women subjects. A total of 500 AO subjects (age 49.1 ± 10.5 years), and 142 non-AO women subjects (age 49.9 ± 11.9 years) were enrolled for the general biochemistry tests, serum BChE, fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Body mass index, waist circumference, Blood pressure (BP), plasma glucose (Glu), triglyceride (TG), BChE, insulin, HOMA-IR were significantly higher and HDL-C levels were significantly lower in AO subjects (p < 0.05). Waist circumference was significantly correlated with BP, Glu, TG, BChE, insulin and HOMA-IR in AO subjects. Multiple logistic regression demonstrated that AO was associated with elevated BChE, HOMA-IR, hypertension and reduced HDL-C after adjusting for these variables. AO is associated with elevated BChE, insulin resistance, HT and reduced HDL-C. These may predict the development of type 2 diabetes mellitus and may be associated with cognitive disorder in the future, both are mediated through insulin resistance.     

Correlations of Insulin Resistance and Serum Testosterone Levels with LH:FSH Ratio and Oxidative Stress in Women with Functional Ovarian Hyperandrogenism

Functional ovarian hyperandrogenism (FOH) is a form of polycystic ovary syndrome (PCOS) characterized by elevated circulating levels of androgens derived from the ovary. Insulin resistance (IR) is the most common etiological factor in women with FOH. IR causes the generation of increased oxidative stress (OS) and diminished antioxidant status. OS is directly correlated with both IR and testosterone levels, which consequently contribute to endocrine and biochemical alterations in FOH women. In the current study, elevations in total testosterone, free testosterone and luteinizing hormone (LH) levels accompanied by a decrease in follicle stimulating hormone (FSH) level leading to higher LH:FSH ratio were the prominent endocrine changes observed in women with FOH. A significant increase in fasting blood levels of glucose and insulin, as well as an elevated IR were also seen in FOH women, as compared to their age matched controls. Women with FOH have higher pro-oxidant and lower anti-oxidant levels in blood than their age matched controls. In FOH women, elevations in LH:FSH ratio and OS are correlated more with hyperandrogenemia than with IR. Of the androgens, free rather than total testosterone has better positive correlations with elevated LH:FSH ratio and OS, and hence, the former is a better predictive marker for the development of biochemical PCOS in women with FOH.     

Evaluation of Low Blood Lead Levels and Its Association with Oxidative Stress in Pregnant Anemic Women: A Comparative Prospective Study

To correlate blood lead levels (BLLs) and oxidative stress parameters in pregnant anemic women. A total of 175 pregnant women were found suitable and included for this study. Following WHO criteria, 50 each were identified as non-anemic, mild anemic and moderate anemic and 25 were severe anemic. The age of all study subjects ranged from 24–41 years. At admission, BLLs and oxidative stress parameters were estimated as per standard protocols and subjected with ANOVA, Pearson correlation analysis and cluster analysis. Results showed significantly (p < 0.01) high BLLs, zinc protoporphyrin (ZPP), oxidized glutathione (GSSG), lipid peroxide (LPO) levels while low delta aminolevulinic acid dehydratase (δ-ALAD), iron (Fe), selenium (Se), zinc (Zn), haemoglobin (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), red blood cell (RBC) count, reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (TAC) in all groups of anemic pregnant women as compared with non anemic pregnant women. In all groups of pregnant women, BLLs showed significant (p < 0.01) and direct association with ZPP, GSSG and LPO while inverse relation with δ-ALAD, Fe, Se, Zn, Hb, Hct, MCV, MCH, MCHC, RBC, GSH, SOD, CAT and TAC. Study concluded that low BLLs perturb oxidant-antioxidant balance and negatively affected hematological parameters which may eventually Pb to Fe deficiency anemia during pregnancy.