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251.
Acupuncture analgesia is an important issue in veterinary medicine. This study was designed to elucidate central modulation effects in response to electroacupuncture (EA) at different acupoints. Manganese-enhanced functional magnetic resonance imaging was performed in Sprague-Dawley rats after sham acupuncture, sham EA, or true EA at somatic acupoints. The acupoints were divided into 3 groups: group 1, analgesic acupoints commonly used for pain relief, such as Hegu (LI 4); group 2, nonanalgesic acupoints rarely used for analgesic effect, such as Neiguan (PC 6); and group 3, acupoints occasionally used for analgesia, such as Zusanli (ST 36). Image acquisition was performed on a 1.5-T superconductive clinical scanner with a circular polarized extremity coil. The results showed that there was no neural activation caused by EA at a true acupoint with shallow needling and no electric current (sham acupuncture). When EA at a true acupoint was applied with true needling but no electric current (sham EA), there was only a slight increase in brain activity at the hypothalamus; when EA was applied at a true acupoint with true needling and an electric current (true EA), the primary response at the hypothalamus was enhanced. Also, there was a tendency for the early activation of pain-modulation areas to be prominent after EA at analgesic acupoints as compared with nonanalgesic acupoints. In conclusion, understanding the linkage between peripheral acupoint stimulation and central neural pathways provides not only an evidence-based approach for veterinary acupuncture but also a useful guide for clinical applications of acupuncture.  相似文献   
252.
黄杜鹃花杀虫成分及其对斜纹夜蛾的活性   总被引:12,自引:0,他引:12  
用甲醇浸提黄杜鹃花后,以石油醚、二氯甲烷、乙酸乙酯等为溶剂,用不同方法萃取甲醇浸提物,提取其中的杀虫活性成分。活性跟踪结果表明,乙酸乙酯萃取物活性高于其它萃取物。从乙酸乙酯萃取物分离出闹羊花素-Ⅲ和其它8个流分。所分离的闹羊花素-Ⅲ对斜纹夜蛾4龄幼虫的非选择性AFC50为16.48mg/L;点滴法测定LD50为16.42μg/头;抑制体重增长的IC50为41.70mg/L;闹羊花素-Ⅲ活性显著高于其它流分。  相似文献   
253.
农药复配最佳增效配方筛选方法的探讨   总被引:24,自引:1,他引:24  
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   
254.
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 (Mw) 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 Mw. As a result, the conditions seem appropriate for measurement of physical characteristics of β-glucans in cereal products.  相似文献   
255.
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  
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   
256.
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   
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