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241.
In a previous study, a flavonoid-rich extract of Hypericum perforatum L. (FEHP) was prepared and its antioxidant activity was determined by a series of models in vitro. In this study, the hypocholesterolemic effects of FEHP in rats fed a cholesterol-rich diet were tested. Forty Wistar rats fed a standard laboratory diet or a cholesterol-rich diet for 16 weeks were used. The serum lipid levels, as well as malondialdehyde (MDA) and activity of superoxide dismutase (SOD) and catalase (CAT) in serum and liver, were examined. Cholesterol-rich diet induced hypercholesterolemia was manifested in the elevation of serum lipid levels such as total cholesterol (TC), total triglycerides (TG), and low density lipoprotein cholesterol (LDL-C). Administration of middle-dose (75 mg/kg of BW/day) and high-dose (150 mg/kg of BW/day) FEHP significantly lowered the serum levels of TC, TG, and LDL-C, while increasing the serum level of high density lipoprotein cholesterol (HDL-C). Also, the content of MDA in serum and liver decreased significantly after oral administration of FEHP compared with those of rats fed a cholesterol-rich diet. In addition, FEHP increased the activity of SOD in serum and liver, but the activity of CAT was significantly elevated only in liver. These results suggested that the hypocholesterolemic effects of FEHP might be due to its abilities to lower serum TC, TG, and LDL-C levels as well as to slow the lipid peroxidation process and to enhance the antioxidant enzyme activity.  相似文献   
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243.
In this paper through the static loading tests of 6 inflexion zones and 2 cantilever zones in full-size constrained R/C beams, the stress performance in rebars cut-in-phases and subjected to negative moment is studied. The stress properties of extended length of rebars with different shear-span ratiosare analysed on basis of the full measurement of strain distributions combined with the investigation on state and regularity of the diagonal cracks development and series of new knowledge are obtained. It is found that current Concrete Design Code provisions on the extended length are inadequate for the high shear-span ratio and superfluous for the low shear-span ratio. The theoretical and experimental foundations are provided for determining proper value of extended length for rebars cut-in-phases.  相似文献   
244.
Membership functions.formed with the characteristic values obtained by applying the continuous reaction time (CRT) theory from controls and heptic encephalopthy and proposedin this paper.whith these membership functions,the CRT data to be diagnosed are calculated in advance,and then discriminated by BP meural network to differentiate patients with or without braindysfunction.The troubles of low accuracy and efficiency,encountered in training BP network withfuzzy samples.scattered data and extended samples,are solved.  相似文献   
245.
The FCBP(Fuzzy calculating BP) algorithm which is proposed by this paper hasovercome the sensitivity for samples,reduced the number of input layer's samples,lightened the burden of input layer.it is suitable to fuzzy inference and pattern recognition.  相似文献   
246.
This poper sets up a new Neural Network Fuzzy inference Cooperation system which is based on fuzzy inference principle in Expert Systems,take advantage of the powerful learning function, the little sensitivity to input layer's samples,and the fast convergence and so on in FCBP and take advantage of the good sort property and good suit property to fuzzy value in MFART Network.  相似文献   
247.
基于近红外高光谱图像的黄瓜叶片色素含量快速检测   总被引:5,自引:0,他引:5  
利用高光谱图像技术和高效液相色谱法(HPLC)快速检测了新鲜黄瓜叶中叶绿素a、叶绿素b、β-胡萝卜素和叶黄素4种色素含量。采集了120片黄瓜叶的近红外高光谱图像数据以及用HPLC精确测定黄瓜叶中色素含量;提取高光谱图像中50×50像素感兴趣区域(ROI)的平均光谱与4种色素含量分别建立偏最小二乘(PLS)预测模型;为了提高模型的稳定性和预测精度,分别采用区间偏最小二乘(iPLS)、向后区间偏最小二乘(BiPLS)和联合区间偏最小二乘(SiPLS)对各种色素对应的特征波段进行优选,同时对光谱划分数进行了优化。结果表明BiPLS和SiPLS对应模型的预测效果较好,对叶绿素a、叶绿素b、β-胡萝卜素和叶黄素4种色素的预测集相关系数RP分别为0.825 7、0.813 4、0.811 6、0.826 2。  相似文献   
248.
本项目研究了沙棘籽原花青素提取物对小鼠体内免疫调节作用。根据沙棘籽原花青素提取物软胶囊人体推荐日摄入量0.0433g/kg BW扩大10、20、30倍设置低、中、高3个剂量组,即0.433、0.867、1.300g/kg BW,另设阴性对照组和溶剂对照组。采用SPF级昆明种小鼠,连续经口灌胃给予,30d后开始实验。实验结果以P〈0.05判断为显著性差异,研究结果显示:与溶剂对照组及阴性对照组比较,沙棘籽原花青素提取物能明显增强ConA诱导的小鼠脾淋巴细胞增殖能力,明显增强二硝基氟苯诱导的小鼠迟发型变态反应,明显升高小鼠血清溶血素含量,明显增强小鼠腹腔巨噬细胞吞噬鸡红细胞功能,明显增强小鼠碳廓清能力,明显增强抗体生成细胞能力。另外与阴性对照组和溶剂对照组相比,各剂量组对小鼠的脾和胸腺均无明显影响。结果提示:沙棘籽原花青素能显著提高小鼠免疫力,同时不会影响小鼠的免疫器官,无负面影响。  相似文献   
249.
农业机器人研究现状及发展趋势   总被引:2,自引:0,他引:2  
对国内外最新农业机器人研究成果进行了综合研究。介绍了农业机器人的国内外发展现状,对当前农业机器人进行分类阐述,分析了当前农业机器人的工作原理和关键技术,最后对我国农业机器人的发展趋势进行了预测。   相似文献   
250.
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