The thought of using branched-chain amino acids (BCAA) in the prevention and treatment of certain disorders is becoming increasingly popular. Individual BCAA use has been associated with improving glucose tolerance an...The thought of using branched-chain amino acids (BCAA) in the prevention and treatment of certain disorders is becoming increasingly popular. Individual BCAA use has been associated with improving glucose tolerance and liver disease. Previous studies have cited improvements in glucose metabolism with a single dose of L-isoleucine (ILE). However, it is still unclear whether chronic consumption of ILE has any direct benefit. The objective of this study was to examine the influence of chronic ILE supplementation alone or in combination with exercise on fasting serum glucose, insulin, lipids, and lipoprotein cholesterol levels;glucose tolerance;and hepatic lipids in rats. Male Sprague-Dawley rats (n = 40) were divided into Control (low fructose diet);High Fructose diet (HF);HF plus 1.5% ILE (HF + ILE);HF plus exercise (HF + EX);and HF plus 1.5% ILE and exercise (HF + ILE + EX). The HF diets consisted of 70% kcalories from fructose. After 6 weeks of treatment, no significant differences were observed between groups for changes in fasting serum glucose, insulin, lipids, or lipoprotein cholesterol levels. However, hepatic total cholesterol was significantly lower in the HF + ILE + EX compared to the Control and HF, while, the HF + ILE had significantly lower hepatic free cholesterol compared to the HF. We also found no differences between groups for serum glucose response following an oral glucose tolerance test. In conclusion, our study shows that ILE supplementation in rats does not influence serum glucose and lipid biomarkers but may have an influence on lipid metabolic pathways within the liver.展开更多
L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正...L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。展开更多
针对L波段数字航空通信系统(L-band digital aeronautic communication system,LDACS)可用频谱资源有限且易受大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出一种基于降维循环谱和残差神经网络的频谱感知方法。首...针对L波段数字航空通信系统(L-band digital aeronautic communication system,LDACS)可用频谱资源有限且易受大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出一种基于降维循环谱和残差神经网络的频谱感知方法。首先理论推导分析了DME信号的循环谱特征;然后利用Fisher判别率(Fisher discriminant rate,FDR)提取循环频率能量最大的向量,通过主成分分析(principal component analysis,PCA)进行预处理特征增强;最后给出数据处理后的循环谱向量与卷积神经网络相结合的实现过程,实现了DME信号的有效检测。仿真结果表明,该方法对噪声不敏感,当信噪比不低于-15 dB时,平均检测概率大于90%。当信噪比不低于-14 dB,检测概率接近100%。展开更多
文摘The thought of using branched-chain amino acids (BCAA) in the prevention and treatment of certain disorders is becoming increasingly popular. Individual BCAA use has been associated with improving glucose tolerance and liver disease. Previous studies have cited improvements in glucose metabolism with a single dose of L-isoleucine (ILE). However, it is still unclear whether chronic consumption of ILE has any direct benefit. The objective of this study was to examine the influence of chronic ILE supplementation alone or in combination with exercise on fasting serum glucose, insulin, lipids, and lipoprotein cholesterol levels;glucose tolerance;and hepatic lipids in rats. Male Sprague-Dawley rats (n = 40) were divided into Control (low fructose diet);High Fructose diet (HF);HF plus 1.5% ILE (HF + ILE);HF plus exercise (HF + EX);and HF plus 1.5% ILE and exercise (HF + ILE + EX). The HF diets consisted of 70% kcalories from fructose. After 6 weeks of treatment, no significant differences were observed between groups for changes in fasting serum glucose, insulin, lipids, or lipoprotein cholesterol levels. However, hepatic total cholesterol was significantly lower in the HF + ILE + EX compared to the Control and HF, while, the HF + ILE had significantly lower hepatic free cholesterol compared to the HF. We also found no differences between groups for serum glucose response following an oral glucose tolerance test. In conclusion, our study shows that ILE supplementation in rats does not influence serum glucose and lipid biomarkers but may have an influence on lipid metabolic pathways within the liver.
文摘L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。
