Oxytocin: crystal data of a seleno analog     

C C Chiu  I L Schwartz  R Walter 《Science (New York, N.Y.)》1969,163(870):925-926

The sulfur atom in position 6 of deamino-oxytocin (1-beta-mercapto-propionic acid-oxytocin) was replaced by selenium. The crystals of the resulting deamino-6-seleno-oxytocin are similar to those of the "wet" form of deamino-oxytocin, but they are stable upon prolonged exposure to air.  相似文献   

Lewy bodies of Parkinson's disease contain neurofilament antigens   总被引：16，自引：0，他引：16  

J E Goldman  S H Yen  F C Chiu  N S Peress 《Science (New York, N.Y.)》1983,221(4615):1082-1084

The Lewy body, a histological hallmark of Parkinson's disease, is a filamentous inclusion residing most prominently in pigmented neurons of the brainstem. Immunocytochemical reactions of Lewy bodies were examined with antisera to several filamentous proteins of the nervous system and positive reactions were found with those against neurofilaments. An abnormal organization of the neuronal cytoskeleton may be a pathological feature of Parkinson's disease.  相似文献   

农药复配最佳增效配方筛选方法的探讨   总被引：25，自引：1，他引：24  

陈立  徐汉虹  李云宇  何嫏芬  赵善欢 《植物保护学报》2000,27(4):349-354

复配农药增效作用的定量测定是配方筛选的重要依据。以斜纹夜蛾（Ｓｐｏｄｏｐｔｅｒａ ｌｉｔｕｒａ）为试虫,采用Ｐｏｔｔｅｒ喷雾法测定了氯氰菊酯、喹硫磷、毒死蜱、丙硫磷、丙溴磷、灭多威、敌敌畏对斜纹夜蛾２龄幼虫的毒力。根据共毒因子法确定氯氰菊酯与喹硫磷混配为最佳配伍。根据等效线法中相加作用线的十等分点氯氰菊酯与硫磷的配比分别为１：１８、１：８、３：１４、１：３、１：２、３：４、７：６、２：１、９：２,  相似文献   

闹羊花素-Ⅲ对菜青虫神经系统的影响   总被引：5，自引：0，他引：5  

钟国华  胡美英  赵善欢  程东美 《农药学学报》2000,2(1):13-18

以闹羊花素－Ⅲ处理5龄菜青虫幼虫,试虫乙酰胆碱酯酶（AChE)的活体活性和离体活性均与对照无明显差异,乙酰胆碱（ACh)含量显降低,对Na^ -K^ -ATP酶,Ca^2 -Mg^2 -ATP酶比活力有可逆性激活作用,处理后24h比活力提高,尤以低剂量1ug.虫^-1处理的比活力显提高;处理后60h,以1－3ug.虫^-1处理的比活力恢复政党,以5－10ug.虫^-1处理的比活力显低于对照。  相似文献   

β-Glucanase Activity and Molecular Weight of β-Glucans in Barley After Various Treatments     

Benny E. Knuckles  Mei-Chen M. Chiu 《Cereal Chemistry》1999,76(1):92-95

β-Glucanase activity interferes with molecular characterization of mixed-linkage (1→3)(1→4)-β-d -glucans (β-glucans). Reductions in β-glucanase activity were determined after barley cvs. Azhul, Waxbar, and Baronesse were treated with autoclaving (120°C, 45 min), calcium chloride (0.05M, 1 hr), 70% ethanol (80°C, 4 hr), hydrochloric acid (0.1N, 1 hr), oven heating (120 and 140°C, 40 min), sodium hydroxide (0.0025M, 1 hr), and 5% trichloroacetic acid (TCA) (40°C, 1 hr). High-performance size-exclusion chromatography (HPSEC) of α-amylase-treated aqueous extracts was used to demonstrate the effects of treatments on the molecular weights of β-glucans. The HPSEC system included multiple-angle, laser light scattering, refractive index, and fluorescence detectors. β-Glucanase activities, ranging from 52 to 65 U/kg of barley, were reduced by autoclaving (50–75%), hot alcohol (67–76%), oven heating (40–96%), CaCl₂ (75–95%), NaOH (76–89%), and TCA (92–96%). Some malt β-glucanase activity remained after most treatments. HCl and TCA treatments reduced extraction and molecular weights of β-glucans. Weight-average molecular weights (M_w) for β-glucans extracted with water at 23°C were low (most <8 × 10⁵). Base treatment (pH 9) and extraction at 100°C for 2.5 hr resulted in the greatest extraction of β-glucans and highest M_w. As a result, the conditions seem appropriate for measurement of physical characteristics of β-glucans in cereal products.  相似文献   

引种印楝国产种子的印楝素含量及杀虫活性初步研究   总被引：27，自引：2，他引：27  

张业光  张兴等 《华南农业大学学报》1992,13(1):14-19

应用高效液相色谱法（HPLC）定量分析结果表明,从海南省种植的印楝树（Azodirochta indica A.Juss)上收获的种子中印楝素（Azadirachtin)含量为0．48％,甲醇提取物获得率为16．395,其中含印楝素2．95,国产印楝种子提取物对亚洲玉米螟（Ostrinia furnccalis)和小菜蛾（Ptutella xylostella)幼虫均有强烈的抑制生长发育作用活性,提取物馏分F3－5（含印楝素0．883％）500ppm饲喂亚洲玉米螟4－5龄幼虫造成100％畸形死亡和变成“永久性幼虫”,113ppm时也有显著效果,2％处理小菜蛾四龄幼虫也使之100％畸形死亡,试验还发现不含印楝素的其它馏分对上两种害虫也有不同程度的作用效果,值得进一步研究。  相似文献   

Shortened Temperature Program for Application with a Rapid Visco Analyser in Prediction of Noodle Quality in Wheat     

G. B. Crosbie  P. C. Chiu  A. S. Ross 《Cereal Chemistry》2002,79(4):596-599

The use of the Rapid Visco Analyser (RVA) for application in the screening of wheat breeding lines for starch quality and potential noodle quality has been limited by relatively low sample throughput. Current methods generally enable only 20–30 samples to be tested each day. This study sought to develop a more rapid time‐temperature profile that could be applied to whole meal samples. A profile that involved a total analysis time of 7.5 min/sample gave measurements of peak viscosity (PV) and breakdown (BD) on whole meal that were highly correlated with corresponding measurements obtained using a more conventional profile that had been applied to low‐extraction flours. BD and PV were also highly correlated with the total texture score of ramen (Chinese‐style alkaline noodles as manufactured in Japan), but only when 1 mM AgNO₃ was used to eliminate the effects of α‐amylase.  相似文献