水杨酸对盐胁迫下油菜幼苗生长抑制的缓解效应

以油菜品种＂美国巨荚油王＂为材料,采用室内水培实验研究了不同浓度SA处理对0.1mmol/LNaCl胁迫下油菜幼苗生长的影响.结果表明：盐胁迫下,油菜幼苗叶片内叶绿素含量及过氧化物酶活性明显降低,脯氨酸和丙二醛（MDA）含量明显增加.外施SA明显提高了盐胁迫下油菜幼苗叶片内叶绿素含量、过氧化物酶活性及脯氨酸含量,使膜脂过氧化产物MDA含量明显降低.外施SA可以缓解盐胁迫对幼苗生长的抑制作用,并以0.15mmol/L,0.2mmol/L SA缓解效果最好.     

耐高温乳酸菌的筛选

通过初筛、复筛,获得一株耐高温且产酸能力较强的菌株Y5,对该菌株进行了形态学和生理生化特性鉴定,确定此菌株为乳酸茵．通过单因素试验和正交试验确定菌株Y5的最佳产酸条件：发酵温度为55℃,转速为60r／min,接种量为7％,装液量为100mL．     

氨系水相优化合成CdTe量子点的研究

用巯基丙酸（MPA）作稳定剂,无需氮气或氩气保护下,在氨系水相中通过超声合成CdTe量子点的前驱体,前驱体经水浴回流制备粒径可调的CdTe量子点．通过荧光和吸收光谱、透射电子显微镜和红外光谱对产物进行了表征．试验表明：反应时间、温度、pH值、Cd^2＋、HTe^-、MPA的物质的量比,对量子点的粒径大小、粒径分布和粒径生长速度均有很大的影响．n（HTe^-）：n（Cd^2＋）：n（MPA）：1：3：6,pH=9．8条件下合成前驱体,在92＋1℃水浴下回流,可以快速获得长波长、高荧光的CdTe量子点,合成的量子点储存6个月后经稳态／瞬态荧光光谱仪测定,外量子效率仍为16．45％．     

不同厂家生产Vc药片中抗坏血酸含量的测定及比较

Vc分子中的烯二醇基具有较强的还原性,能被I₂定量地氧化成二酮基。采用直接碘量法测定及比较不同厂家生产的Vc药片中抗坏血酸的含量,各组平行测定的标准偏差较小,显著性检验中t值均较小,两组测定不存在显著性差异。     

丙纶LB450和LB500耐酸腐蚀性能比较

为探究袋式除尘滤料丙纶LB450和LB500的表面改性问题,利用溶液腐蚀法,在酸度、温度和时间三因素实验水平下,比较了二者的耐酸腐蚀性能。结果表明：LB500的耐腐性能优于同条件下的LB450;当温度低于40℃,二者适宜长时间使用;程度不同的氧化作用可能是造成耐腐性能差异的主要原因.     

不同品种蜂蜜中总糖的含量测定

对利用蒽酮硫酸法测定蜂蜜中总糖的条件进行了优化选择,并对其应用性进行了评估,结果表明,糖与蒽酮硫酸水溶液共热生成的蓝色络合物在624nm处吸收峰最高;水浴加热4min,加蒽酮硫酸水溶液6.5mL时,总糖的质量浓度与吸光度有很好的线性关系.通过计算对比不同种蜂蜜中总糖含量存在着显著性差异.     

人工北虫草僵虫粗多糖的提取与测定

通过单因素试验和正交试验分析料液比、浸提温度、浸提时间和浸提次数对人工北虫草僵虫（菌核）粗多糖得率的影响,结果表明：随浸提温度、浸提时间和浸提次数的增加,粗多糖得率逐渐上升;随料液比提高,粗多糖得率呈先上升后下降的趋势;影响粗多糖得率的主效因素是浸提温度,其次为浸提时间和浸提次数;确定最佳浸提条件为：浸提温度100℃,料液比1∶20,浸提时间3h,浸提2次,在此条件下北虫草僵虫粗多糖得率为8.497%.     

Citric acid reduces the decline in P300 amplitude induced by acute alcohol consumption in healthy adults

Event-related potential (ERP) is a reliable neuroelectric measure of brain activity that helps to confirm the assessment of mental status and cognitive impairment. Many studies have reported that alcoholics show a significantly lower ERP P300 amplitude than the norm. In the present study, ERP P300 waves were measured to evaluate the effect of citric acid on cognitive function during excessive alcohol consumption in healthy adults. Five volunteers were selected through clinical interview, physical examination, and psychiatric assessment for participation in this study. In a double-blind placebo-controlled before-after design, each subject was treated with 5 ml/kg body weight alcohol, 5 ml/kg body weight alcohol and 1 mg citric acid, or a placebo on three separate occasions, one week apart. ERP P300, blood biochemical indicators, blood alcohol concentrations (BACs) and acetaldehyde concentrations were assessed. Repeated measure analysis of variance (ANOVA) with a within-subjects factor was used to evaluate differences in blood biochemical indicators, BACs, blood acetaldehyde concentrations, and ERP P300 in the three sessions of assessments. Several blood biochemical indicators showed significant differences between treatments, including the levels of cholinesterase (CHE), total bile acid (TBA), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and glycylproline dipeptidyl aminopeptidase (GPDA). BACs after consumption of alcohol alone or citric acid with alcohol were significantly higher compared to those after placebo treatment (P<0.05). There were no significant differences in blood acetaldehyde concentrations between the treatments. The P300 amplitudes on the frontal (Fz), central (Cz), and parietal (Pz) regions of the scalp after consumption of alcohol were significantly lower than those after consumption of the placebo or citric acid with alcohol (P<0.05), while there were no significant differences between the latter two treatments. The results of this study suggest that citric acid could reduce the decline in ERP P300 amplitude and cognitive ability induced by acute alcohol consumption. It may also affect some blood biochemical indicators, but the specific mechanisms need further research.     

Quantitative structure-activity relationships of antimicrobial fatty acids and derivatives against Staphylococcus aureus

Fatty acids and derivatives (FADs) are resources for natural antimicrobials. In order to screen for additional potent antimicrobial agents, the antimicrobial activities of FADs against Staphylococcus aureus were examined using a microplate assay. Monoglycerides of fatty acids were the most potent class of fatty acids, among which monotridecanoin possessed the most potent antimicrobial activity. The conventional quantitative structure-activity relationship (QSAR) and comparative molecular field analysis (CoMFA) were performed to establish two statistically reliable models (conventional QSAR: R ²=0.942, Q ² _LOO=0.910; CoMFA: R ²=0.979, Q ²=0.588, respectively). Improved forecasting can be achieved by the combination of these two models that provide a good insight into the structure-activity relationships of the FADs and that may be useful to design new FADs as antimicrobial agents.     

杂多酸合成维生素E乙酸酯与光谱表征

利用新型催化剂杂多酸H3PMo12O40合成了维生素E乙酸酯,研究了催化剂用量、反应物配比、反应时间、反应温度等因素对合成的影响,通过模糊数学模型确定了最佳合成条件,最优合成工艺：温度40℃,时间3 h,乙酸酐与维生素E摩尔比1.0,杂多酸H3PMo12O40催化剂用量1.2 g,反应酯化率为97.6%.利用IR、元素分析和1HNMR对产物结构进行了表征,证明了得到的产物为维生素E乙酸酯.