The use of enzymic hydrolysis in vitro to study the digestibility of some phaseolus seed proteins

In vitro proteolysis was used to study the digestibility of the major seed protein phaseolin, and the trypsin inhibitor, purified fromPhaseolus vulgaris seeds. Whereas denatured phaseolin was fully digested by the enzymic method used [4], its native form was only partially digested. Trypsin inhibitor, both native and after heat treatment, was poorly digested. It was also found that native trypsin had some resistance to digestion conferred upon it by the presence of the inhibitor.     

甘蔗转化酶抑制子(SoInvInh1)基因克隆和表达分析

采用cDNA末端快速克隆(Rapid amplification of cDNA ends,RACE)技术,以甘蔗未成熟茎cDNA为模板克隆转化酶抑制子,命名为SoInvInh1,GenBank登录号KF575175。SoInvInh1基因的cDNA序列全长为678bp,3′-UTR长146bp。开放阅读框长531bp,编码176个氨基酸,预测分子质量和等电点分别为18.09ku和8.52。SoInvInh1不含内含子序列。预测该蛋白N端具有1个信号肽和跨膜结构,19—172位氨基酸是PMEI蛋白的保守结构域。不同物种间InvInh蛋白氨基酸序列同源性较低,但都具有4个保守的Cys位点。荧光定量PCR分析表明在甘蔗茎、叶、花序和花序轴中都能检测到SoInvInh1基因表达。在甘蔗生长的不同时期,SoInvInh1在叶中表达无明显规律。而在工艺成熟期和生理成熟前期SoInvInh1整体上表现为幼茎中基因表达量高,而老茎中基因表达量低,表明茎中该基因可能与酸性转化酶活性相关。     

GP—1输气管道缓蚀剂的研制

由于管输天然气中硫化氢和水含量较高,管道内壁腐蚀程度呈增长趋势,近年来未保护管道的腐蚀穿孔及硫化物应力腐蚀开裂事故时有发生,严重影响了输气生产。为提高抑制局部腐蚀能力及综合性能,研制了GP-1输气管道缓蚀剂。该缓蚀剂是酰胺化合物复配其他缓蚀组分的复合型缓蚀剂。通过室内评定(挂片失重法和电化学方法)及现场模拟试验,认为GP-1缓蚀剂浓度为100×10~(-6)时,其缓蚀率已达97.7％,且抑制坑蚀能力较强,综合性能良好,适用于抑制含硫化氢的天然气集输管道的内壁腐蚀。     

两类甜菜碱型表面活性剂缓蚀行为的研究

采用电化学和失重法研究了月桂酰胺甜菜碱和月桂基二甲基甜菜碱在硫酸溶液中对碳钢的腐蚀化学行为和吸附规律。实验表明，它们均具有较好的缓蚀性能，月桂酰胺甜菜碱优于月桂基二甲基甜菜碱。它们属阳极控制型缓蚀剂，吸附过程为放热反应，属化学吸附，在不同咐区间分别遵循Ｔｅｍｉｎ和Ｆｒｕｍｋｉｎ吸附等温式。     

Effect of phytic acid and phytase on feed intake, growth, digestibility and trypsin activity in Atlantic salmon (Salmo salar, L.)

In the majority of experiments, the effects of phytic acid (with or without phytase) are not separated from the effects of adding plant meals containing phytic acid. A 12‐week experiment was conducted with Atlantic salmon (28.9 g) to determine the separate and combined effects of phytic acid and phytase on feed intake, trypsin activity, digestibility and growth. Diets were prepared without phytic acid and phytase; with 2000 U phytase kg^?1 diet; with 10 g sodium phytate kg^?1 diet; and with 10 g sodium phytate and 2000 U phytase kg^?1 diet. The basal diet contained sufficient phosphorus and other minerals to meet salmonid requirements. The addition of phytic acid had no significant effect on feed intake or weight gain, it significantly (P < 0.05) reduced protein digestibility although there was no reduction in trypsin activity. Phytase inclusion neutralized the effect of phytic acid on protein digestibility. Phytase had no effect on feed intake but significantly enhanced growth whether included with or without phytic acid. Feed efficiency ratio was significantly improved for fish fed the diet containing both phytase and phytic acid but not separately. The significance of this experiment was to separate the direct effects of phytase and the direct effects of phytic acid, added in a pure form, from effects due to other components in ingredients containing phytic acid.     

Phosphodiesterase 3 inhibitor attenuates cough response in a sensitized guinea pig model

AIM: To investigate the effects of selective phosphodiesterase 3 inhibitor olprinone on cough response in guinea pigs sensitized and challenged with ovalbumin.METHODS: Forty sensitized guinea pigs were randomly divided into control (n=10), challenged (n=10), olprinone (n=10) and aminophylline group (n=10). Two hours after challenged with the aerosol of 1% ovalbumin or saline, animals were intraperitoneally injected either with saline, 25 mg/kg of olprinone or 25 mg/kg aminophylline. At 24 h, the injection was repeated with 2.5 mg/kg and 25 mg/kg olprinone or 2.5 mg/kg and 25 mg/kg aminophylline respectively in olprinone and aminophylline group, cough response to inhaled capsaicin and airway responsiveness to methacholine (PC150) were measured. Then, total cell number and differential counts were analyzed in bronchoalveolar lavage fluid. RESULTS: The cough frequency was (5±2) times/3 min in control group and (24±3) times/3 min in challenged group (P<0.05), while PC150 was (659±57) mg/L in control group and (238±67) mg/L in challenged group (P<0.05). 25 mg/kg olprinone significantly inhibited the augmented cough response and airway hyperresponsiveness, the cough frequency and PC150 were (15±2) times/3 min and (580±45) mg/L (P<0.05), which differed significantly from (18±2) times/3 min and (438±52) mg/L in aminophilline group (P<0.05). However, olprinone failed to reverse the elevated total cell number and percentage of eosinophils in bronchoalveolar lavage fluid from guinea pigs challenged with ovalbumin (P>0.05).CONCLUSION: Phosphodiesterase 3 inhibitor attenuates cough response associated with eosinophilic airway inflammation by bronchodilatory effect.     

乙烯利在草坪上的应用研究进展

本文综述了乙烯利用对草坪草生长发育和抗逆性的影响。并且指出乙烯利可有效降低草坪株高、减少修剪次数、促进草坪草分蘖、改善草坪色泽、提高草坪的抗逆性，从而形成高质量草坪、降低养护管理费用。     

水溶性松香基咪唑啉的合成及缓蚀性能

以脂松香和二乙烯三胺(DETA)为原料，合成了不同环氧乙烷聚合度的水溶性松香基咪唑啉(WRI)。讨论了影响松香基咪唑啉合成反应的主要因素，得出适宜的反应条件：反应温度230-240℃，DETA和松香的摩尔用量比为1．6：1，体系真空度(真空表读数)2．67—5．33kPa。利用静态失重法测定了WRI在盐酸介质中对Q235钢的缓蚀效率，实验结果表明：聚合度为10的水溶性松香基咪唑啉(WRI-10)对Q235钢有较强的缓蚀作用，缓蚀性能优于市售产品苯并三氮唑、乌洛托品和脂肪酸季铵盐“1227”等。     

乳蛋白的胰蛋白酶水解模型的建立

利用脱脂牛乳为原料，对乳蛋白的胰蛋白酶催化水解进行研究，并建立了两个不同温度下的乳蛋白水解物水解度变化模型．所得模型与实测相符．该模型用于一定水解时间内水解物水解度的估测．