不同冷冻保护剂对犬精子冻存的影响

本试验通过对比冷冻保护剂和冷冻程序,优化犬精液冷冻保存方法,比较了不同甘油、乙二醇浓度、不同平衡时间对犬精子冷冻复苏率及精子顶体完整率的影响。结果发现,甘油作为冷冻保护剂时,其对精液冷冻保存后的效果明显优于乙二醇,当甘油浓度为4%时,平均冷冻复苏率最高;冷冻平衡时间为1 h最佳。因此,犬精液在冷冻保存时,甘油浓度为4%,平衡60 min,可获得平均39.21%±0.013%的冷冻复苏率,且比较稳定。     

甘油水溶液提取米糠多酚绿色工艺优化及多酚种类鉴定

为探究甘油作为绿色溶剂提取米糠多酚的可行性,该文选取提取温度、甘油体积分数、液料比和提取时间4个因素,采用单因素结合响应面试验进行米糠多酚提取工艺优化。同时,分析了甘油提取液的黏度特性,并利用超高效液相色谱串联三重四级杆飞行时间质谱(UPLC-Triple-TOF/MS)方法进行多酚鉴定。结果表明,甘油提取米糠多酚最优条件为提取温度67℃,甘油体积分数19%,液料比33 mL/g,提取时间固定为80 min,获得的最大多酚得率为700.35 mg/(100 g)。甘油对米糠多酚的提取效率和甘油的黏度有显著的负相关性。此外,UPLC-Triple-TOF/MS分析表明,最优条件下甘油提取得到13种米糠多酚,其中酚酸质量分数如下:对羟基苯甲酸48.53μg/g,香草酸69.64μg/g,丁香酸33.63μg/g,4-香豆酸361.18μg/g,阿魏酸392.17μg/g,水杨酸34.67μg/g。研究结果表明,甘油可以作为从米糠中提取多酚的绿色溶剂。     

DMA和甘油对公鸡精子冷冻保护作用的比较

比较了6%的DMA和11%的甘油冷冻洪山公鸡精液后精子在存活率、顶体完整率方面的差异.结果表明,用DMA做冷冻保护剂的颗粒型冷冻精液解冻后的精子存活率和顶体完整率分别为0.320±0.041和0.600±0.049,用甘油做冷冻保护剂的颗粒型冷冻精液解冻后的精子存活率和顶体完整率分别为0.313±0.036和0.597±0.040,两者差异不显著.用DMA做冷冻保护剂的细管型冷冻精液解冻后的精子存活率和顶体完整率分别为0.388±0.034和0.652±0.042,用甘油做冷冻保护剂的细管型冷冻精液解冻后的精子存活率和顶体完整率分别为0.433±0.054和0.750±0.048,前者在精子存活率(P＜0.05)和顶体完整率(P＜0.01)方面都显著低于后者.     

Effect of Phenylpyrroles on Glycerol Accumulation and Protein Kinase Activity of Neurospora crassa

The effect of phenylpyrroles on glycerol synthesis in Neurospora crassa has been investigated and compared with the mode of action of vinclozolin (a dicarboximide). The results indicated that fenpiclonil, fludioxonil and vinclozolin at concentrations which inhibit growth by 50% induce accumulation of glycerol in the mycelium of N. crassa. Furthermore a protein kinase (PK-III) possibly involved in the regulation of the glycerol synthesis is inhibited by phenylpyrroles, whereas vinclozolin is without effect. This implies that the target sites of phenylpyrroles and dicarboximides in the osmosensing signal transmission pathway are different. Comparative experiments with enzymes from human and animal sources revealed that PK-III could be a protein kinase Cδ. It is suggested that inhibition of PK-III activity may result in an increased concentration of a non-phosphorylated regulatory protein which may activate a MAP-kinase cascade of reactions resulting in increased glycerol synthesis. © 1997 SCI.     

外源添加乙偶姻对酿酒酵母W5/W141产2,3-丁二醇的影响

本研究旨在获得一株性能良好的2,3-丁二醇(2,3-BD)生产菌株。向酿酒酵母(Saccharomyces cerevisiae) W5/W141两株产2,3-BD菌株中添加不同浓度乙偶姻,并测定2,3-BD、乙醇和甘油产量随发酵时间的变化情况。S. cerevisiae W5最适乙偶姻添加浓度为12 g/L,且2,3-BD的产量在72 h达到最大,产量为2.54±0.03 g/L,甘油和乙醇转化率分别较未添加时下降了17.6%和23.6%。S. cerevisiae W141最适乙偶姻添加浓度为10 g/L,且2,3-BD的产量在72 h达到最大,产量为1.71±0.02 g/L,甘油和乙醇转化率分别较未添加时下降了57.1%和16.7%。通过对比,本课题最终选用S. cerevisiae W5作为最适菌株,为微生物发酵法生产2,3-BD提供新的资源。     

可食性大豆蛋白膜的研制及在切分西瓜保鲜上的应用

以大豆分离蛋白（SPI）膜为基材,蜂蜡、甘油为改性剂,研究新型生物保鲜膜的制备及其对切分西瓜保鲜效果的影响。结果表明,蜂蜡和甘油的改性作用可提高SPI膜的抗张强度（TS）和表面接触角,降低水蒸气透过率（WVP）和断裂延伸率。其中,蜂蜡和甘油最佳添加量分别为6%和40%,WVP值（200.9±13.18）g.m-2·d-1,比未添加蜂蜡的对照膜降低28.9%,TS值（4.27±0.48）MPa,比对照提高54.7%。应用改性的大豆蛋白膜包装的切分西瓜在4℃保鲜3 d时,失重率仅1%,并可有效保持番茄红素含量。     

乙酰丙酮分光光度法测定甘油缩甲醛中游离甲醛含量

乙酰丙酮与甲醛在乙酸-乙酸铵介质中形成黄色化合物,该化合物在411 nm波长处有最大吸收。甲醛在比色液中含量小于4μg/mL时,符合比尔定律,线性相关系数R2=0.999 9。对样品平行6次测定相对标准偏差为0.68%~1.62%,回收率为91.2%~93.8%。该方法测定甘油缩甲醛中游离甲醛含量简便、快捷,准确可靠。     

采用甘油冷冻保存鸡大肠埃希氏菌病灭活疫苗生产用菌种的试验

鸡大肠埃希氏菌病灭活疫苗生产用一级种子按10%加入甘油混匀,分装于灭菌小瓶中,于-80℃条件保存1年,按菌种的标准进行各项特性鉴定,结果细菌的各项特性均符合<中华人民共和国兽用生物制品规程>的规定.     

AQP9在脑疾病中的研究进展

水甘油通道蛋白-9 (AQP9)属于水通道蛋白家族,对水及一些小分子如甘油和尿素具有通透性.论文将集中论述与脑疾病相关的AQP9的最新发现.AQP9表达于星型胶质细胞和儿茶酚胺神经元,脑中AQP9的表达水平受血液中胰岛素浓度的调节,且其在糖尿病病人脑组织中高表达,该研究结果提示AQP9很可能参与脑部能量代谢;中风后AQ...     

Antioxidant properties of feruloyl glycerol derivatives

The natural plant components, 1-feruloyl-sn-glycerol (FG) and 1,3-diferuloyl-sn-glycerol (F₂G), were synthesized by the enzymatic esterification of glycerol and soybean oil mono- and diacylglycerols, respectively, with ethyl ferulate. The isolated FG and F₂G were examined for their antioxidant activities as free radical scavengers (DPPH assay) and peroxyl lipid oxidation inhibitors (TBARS assay). The H atom transfer kinetics, as monitored by DPPH free radical bleaching, of FG showed that the mono-feruloyl glycerol acted as a rapid antioxidant (50% reduction of DPPH radical < 5 min) in ethanol solutions while F₂G and ferulic acid activity rates were in the range of intermediate antioxidants (50% reduction of DPPH radical in 5-30 min). FG and F₂G showed similar activity as the control agent, ethyl ferulate, towards the inhibition of the AAPH-induced peroxyl radical oxidation of surfactant emulsified γ-linolenic acid. A slight excess of feruloyl groups was sufficient to completely suppress the formation of secondary lipid oxidation products.