金银藤挥发油成分的气-质联用分析与化学计量学解析

目的 定性、定量分析金银藤挥发油成分.方法 采用气相色谱-质谱进行检测,通过化学计量学解析法对二雏色谱/质谱数据进行解析,得到各组分的纯色谱曲线和质谱,从而实现对金银藤挥发油成分的定性、定量分析,并结合程序升温保留指数来鉴定化合物.结果 金银藤的挥发油鉴定了39个成分,定性组分含量占金银藤挥发油成分总含量的94.54%.结论 全银藤挥发油的主要成分为十六烷酸（45.86%）、9,12-十八碳二烯政乙酯（39.02%）、十四烷酸（1.8%）、十五烷酸（1.07%）、十八烷酸（1.02%）.     

引种植物水竹芋捕虫行为的初步观察研究

通过对引种植物水竹芋的观察,发现水竹芋的花具有捕捉昆虫的能力,在此基础上对其花进行了解剖结构特征和捕虫行为的观察,并初步探讨了其捕虫行为的生态学意义.观察研究显示,水竹芋开放花以及即将开放花的花柱具有较强的卷曲能力;未开放以及开放后没有被触及的花的花柱被兜状退化雄蕊包被;当昆虫进入饰变雄蕊群形成的筒状结构而触及到兜状退化雄蕊时,花柱因产生应激反应而迅速卷曲,从而将昆虫捕捉.初步观察研究认为,水竹芋不仅具有捕捉昆虫的能力,而且在水污染处理以及湿地的恢复与重建中具有重要的应用潜力.     

利用光子晶体抑制大气窗口发射辐射的优化设计及实验研究

利用传输矩阵法讨论了光子晶体对大气窗口（8～14μm）内发射辐射的抑制作用.根据材料的光学特性,选择了Ge与ZnS作为光子晶体的组成材料.对光子晶体的结构进行了优化,优化值为Ge与ZnS的厚度分别为0.63和1.11μm,光学厚度比为1：1,周期数为8.利用蒸发镀膜制备了光子晶体,并对制得的光子晶体的光学性质进行了测定,验证光子晶体对大气窗口发射辐射的抑制作用.     

酸解法对甘氨酸母液脱色后废活性炭的再生研究

在用海因法生产甘氨酸的过程中,为了精制甘氨酸,需要用大量的活性炭对甘氨酸母液进行脱色,而脱色后的活性炭就成了废活性炭.为了实现废活性炭的再利用,针对此废活性炭用酸解法对其进行再生.研究了再生酸种类、浓度、用量、再生温度和再生时间等对废活性炭再生效果的影响,确定了适宜的再生条件:硫酸质量分数为70％,硫酸溶液与废活性炭的...     

温室春石斛兰花期与外观品质温度调控模型

低温春化处理是保证春石斛兰开花和外观品质的关键技术.针对我国温室春石斛兰生产中普遍存在的因春化阶段温度控制不当,导致不能及时开花和外观品质下降或成为盲花的问题,文中通过不同定植期和不同温度春化处理实验,定量分析了温度对春石斛兰春化进程和产品外观品质的影响,并进一步建立了温室春石斛兰花期与外观品质温度调控模型.用独立的实验资料对模型进行检验,结果表明,模型对不同温度条件下春石斛兰完成春化阶段所需天数、到达采收所需天数和外观品质的预测效果较好.模型对各个生育时期(从春化开始到花芽生长.花芽生长到现蕾,现蕾到始花,始花到采收期)预测值与实测值之间的决定系数R。为0.97,回归统计标准误RMSE分别为1 d(从春化开始到花芽生长)、1.58 d(花芽生长到现蕾)、4 d(现蕾到始花)、6.52 d(始花到采收期).采收时单株花蕾节数与单株花蕾数预测值与实测值之间的R~2分别为0.81和0.84,RMSE分别为0.62/plant和0.65/plant.对不同白天和夜间温度控制目标下,春石斛兰完成春化阶段所需的天数、到达采收所需天数和外观品质的模拟分析结果表明,当夜间温度为9～14℃,白天温度为18～28℃时,春石斛兰产品可以最快上市且外观品质最优.文中建立的模型可以为温室春石斛兰花期与外观品质的温度精准调控提供理论依据和决策支持.     

车载 RFID设备电磁抗扰度测试研究

为了测试 RFID设备在汽车复杂电磁环境下的电磁抗扰度(EMS),提出一套 EMS测试方案.方案采用限值测量法制定,分析干扰信号耦合原理及受试设备工作环境确定了测试项目和测试方法,且从测试结果准确度方面提出了判断测试是否合格的计算公式.按照方案对车载无钥匙进入系统进行了测试,测试结果已被某车厂使用,验证了其可行性.本方案还对于 RFID设备EMS测试规范的制定具有参考价值     

甘草、红景天及黄芪粗提取物对UVB诱导小鼠皮肤慢性光损伤的保护作用

目的研究甘草、红景天和黄芪三种粗提取物对皮肤慢性光损伤的保护作用。方法甘草、红景天和黄芪三种粗提取物局部外用于小鼠背部皮肤后给予UVB辐射,每天1次,连续30天,分别采用TUNEL、ELISA和免疫印迹检测小鼠背部皮肤组织的细胞凋亡指数、TNF-α含量和caspase-8蛋白水平。结果与空白对照组相比,UVB照射组(单纯给予UVB照射)小鼠皮肤中的细胞凋亡指数、TNF-α含量及caspase-8水平均显著增高(P0.05);不同浓度甘草等粗提取物处理后可下调TNF-α、caspase-8表达水平及细胞凋亡指数(P0.05),尤以甘草组明显。结论UVB慢性辐射可诱导皮肤光老化,而甘草、红景天和黄芪三种粗提取物可缓解紫外线引起的皮肤慢性光损伤,其作用机制与抑制炎症因子TNF-α释放、caspase-8表达和细胞凋亡有关。     

疏水性固体酸Zr(SO4)2·4H2O/AC催化合成柠檬酸三乙酯

将Zr(SO4)2·4H2O(ZS)负栽在活性炭(AC)上制备疏水性固体酸ZS/AC催化剂,用于催化合成柠檬酸三乙酯.探讨了各影响因素对柠檬酸三乙酯收率的影响.结果表明,当四水硫酸锆的负载量为30%、催化剂处理温度为110℃、催化剂用量为柠檬酸质量的4%、酸醇摩尔比为1:5.5、100℃反应5 h时,产物收率可达97.6%.催化剂重复使用四次后产率仍保持在93%以上,且易分离,不污染环境.     

嗜酸氧化亚铁硫杆菌蛋白质组研究进展

嗜酸氧化亚铁硫杆菌在生物湿法冶金中具有广泛的应用前景.随着At.f菌分离与鉴定技术和基因组研究的深入,At.f菌的研究已进入蛋白质组水平.本文较详细地归纳总结了嗜酸氧化亚铁硫杆菌蛋白质组研究的最新进展,指出了未来的发展方向.     

木质纤维素类生物质酸水解研究进展

木质纤维素中纤维素和半纤维素经酸水解可转化为糖,糖进一步可生产燃料乙醇和其他化工产品。因此,木质纤维素酸水解制备糖是纤维素转化过程中关键步骤。本文综述了硫酸、盐酸、硝酸、磷酸、马来酸等无机、有机酸水解木质纤维素类生物质研究进展,对各种酸水解工艺的优缺点进行了分析和比较,指出了木质纤维素类生物质酸水解的研究方向。     

Inhibition of growth and lactic acid synthesis inLactobacillus casei by maltol and its reversal by glutamic acid

Summary Maltol inhibited growth and lactic acid synthesis byLactobacillus casei. The inhibition was partially overcome by the addition of casein hydrolysate and yeast extract. Some amino acid mixtures were also effective, among which glutamic acid was able to reverse the inhibition completely.     

Inhibitory effects of phenolic compounds on CCl4-induced microsomal lipid peroxidation

The antiperoxidative effects of 35 phenolic compounds, most of them belonging to the flavonoid class, were investigated using CCl4-induced peroxidation of rat liver microsomes. This system was rather insensitive to gallic acid, methyl gallate and ellagic acid. Nevertheless it was inhibited by flavonoids and structure/activity relationships were established. The most potent compounds were gardenin D, luteolin, apigenin (flavones), datiscetin, morin, galangin (flavonols), eriodictyol (flavanone), amentoflavone (biflavone) and the reference compound, (+)-catechin. The natural polymethoxyflavone gardenin D has shown a potency comparable to that of (+)-catechin and higher than that of silybin. Thus, it may be considered as a new type of natural antioxidant with potential therapeutical applications.     

Inhibitory effects of phenolic compounds on CCl4-induced microsomal lipid peroxidation

Summary The antiperoxidative effects of 35 phenolic compounds, most of them belonging to the flavonoid class, were investigated using CCl₄-induced peroxidation of rat liver microsomes. This system was rather insensitive to gallic acid, methyl gallate and ellagic acid. Nevertheless it was inhibited by flavonoids and structure/activity relationships were established. The most potent compounds were gardenin D, luteolin, apigenin (flavones), datiscetin, morin, galangin (flavonols), eriodictyol (flavanone), amentoflavone (biflavone) and the reference compound, (+)-catechin. The natural polymethoxyflavone gardenin D has shown a potency comparable to that of (+)-catechin and higher than that of silybin. Thus, it may be considered as a new type of natural antioxidant with potential therapeutical applications.     

Prevention of the formation of mycotoxins in whole wheat bread by citric acid and lactic acid (Mycotoxins in foodstuffs. IX)

Summary Additions of citric acid and lactic acid to whole wheat bread suppress the formation of aflatoxins byAspergillus parasiticus (0.5% citric acid, 0.75% lactic acid) and that of sterigmatocystin byA. versicolor (0.25 and 0.5% respectively).Acknowledgment. I thank Dr.R. Orth (Bundesforschungsanstalt für Ernährung, Karlsruhe, BRD) for the strain ofAspergillus versicolor.     

Action of leucine aminopeptidase 1 and 2 (Aspergillus oryzae 410) on various synthetic peptides (author's transl)]

By use of di- or tripeptides as substrates, LAP 1 and LAP 2, 2 fractions from Aspergillus oryzae hydrolyze oligopeptides that possess leucine as N-terminal amino acid. LAP 1 fraction also hydrolyzes the histidyl bond. Both fractions have no activity towards peptides as glutathion, gly-pro-ala; they have low or no activity towards tyrosyl and tryptophanyl bond.     

青蒿水提液对肺癌A549细胞的影响

目的研究青蒿水提液对肺癌A549细胞株增殖的影响和诱导凋亡的情况。方法不同浓度青蒿水提液作用于细胞不同时间,四甲基氮噻唑蓝（MTT）法检测吸光度值（A490nm）并计算增殖抑制率;AnnexinV-FITC／PI荧光染色后流式细胞仪检测细胞凋亡率;并以荧光显微镜观察细胞形态改变情况;蛋白质印迹法分析细胞凋亡相关蛋白Bax、Bcl-2的表这。结果青蒿水提液呈时间和剂量依赖性抑制A549细胞增殖;荧光显微镜下A549细胞出现不同时期凋亡特征性改变;流式细胞仪检测细胞凋亡率随着药物浓度增加而升高;A549细胞株的Bax蛋白表达量增多、Bcl-2蛋白表达量下降。结论青蒿水提液促进体外培养的A549细胞株增殖抑制并诱导凋亡,其机制可能与A549细胞Bax表达上调和Bcl-2表达下调有关。     

Sulla biochimica della fermentazione citrica da parte dell'Aspergillus niger

Summary In a strain ofAspergillus niger grown in Bernhauer medium, oxalacetic decarboxylase activity increased, while citric acid accumulated in the medium. The mechanism of citric acid accumulation is discussed.     

Methylmalonic acid — an endogenous toxin?

Methylmalonic acid was previously considered as major neurotoxin in methylmalonic acidurias. In contrast, recent studies support the notion that other metabolites deriving from propionyl-coenzyme A, inducing synergistic inhibition of mitochondrial energy metabolism, are more important than methylmalonic acid to understand the neuropathogenesis of this disease. However, it is not yet known whether methylmalonic acid is involved in the induction of other organ manifestations in this disease, such as chronic renal failure.Received 21 October 2004; received after revision 29 December 2004; accepted 4 January 2005     

Recombination of integral and peripheral protein fractions from human red cell membrane with homologous lipids

Summary Integral and peripheral protein fractions from human red cell membranes were recombined with a total red cell lipid extract and with homologous lipids in varying mixtures, by dialysis from 2-chlorethanol solutions. The 2 protein fractions were compared for lipid binding capacity and for selectivity towards individual lipids.