目的研究山楂荷叶饮对高脂血症大鼠的作用并探讨其降脂的潜在活性成分及作用靶点。方法建立高脂血症大鼠模型,从血脂水平、体质量、肝脏系数、脂肪质量以及肝脏病理形态变化等方面评价山楂荷叶饮的降脂效果;采用超高效液相色谱-四极杆...目的研究山楂荷叶饮对高脂血症大鼠的作用并探讨其降脂的潜在活性成分及作用靶点。方法建立高脂血症大鼠模型,从血脂水平、体质量、肝脏系数、脂肪质量以及肝脏病理形态变化等方面评价山楂荷叶饮的降脂效果;采用超高效液相色谱-四极杆飞行时间质谱(ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry,UHPLC-QTOF-MS)对山楂荷叶饮中的化学成分进行鉴定,筛选山楂荷叶饮中活性成分与高脂血症的交集靶点,采用STRING数据库对蛋白相互作用网络进行构建与分析,利用Auto Dock Tools软件对活性成分与关键靶点进行分子对接验证。结果山楂荷叶饮能显著降低高脂血症大鼠总胆固醇(total cholesterol,TC)、三酰甘油(triglycerides,TG)和低密度脂蛋白(low-density lipoprotein cholesterol,LDL-C)水平,降低体质量及肝脏指数、附睾脂肪和肾周脂肪质量,改善肝脏组织病理形态、红色脂滴沉积情况。从山楂荷叶饮中共检测鉴定出88个化合物,其中生物碱类27个、黄酮类33个、有机酸类19个、其他类9个。网络药理学分析发现,山楂荷叶饮中金丝桃苷、荷叶碱、槲皮素、乌药碱等10个关键成分可能通过调控10个核心靶点发挥对高脂血症的调节作用。分子对接结果显示,关键成分与核心靶点蛋白结合活性良好。结论山楂荷叶饮可通过改善血脂水平、减少肝脏脂肪堆积等发挥对高脂血症的治疗作用,为山楂荷叶饮降血脂成分和机制的研究及产品的开发提供参考。展开更多
A novel, compact, and highly selective ultra-wideband （UWB） bandpass filter with a narrow notched band is presented. Apart from having a basic structure of a slotline multiple-mode resonator （MMR） and microstrip f...A novel, compact, and highly selective ultra-wideband （UWB） bandpass filter with a narrow notched band is presented. Apart from having a basic structure of a slotline multiple-mode resonator （MMR） and microstrip feed lines, this novel design introduces a cross-coupling between the input and output feed lines to enhance the filter selectivity. The design strictly follows the theory and verified by electromagnetic （EM） simulation and experiments. In addition, the narrow notched band is introduced by embedding a pair of split ring resonators （SRR） in order to reject any undesired existing radio signals that may interfere with the Federal Communications Commission （FCC）-defined UWB band. By changing the structural parameters of SRR, it can be easily tuned to any desired frequency. This filter can be integrated in UWB communication systems and efficiently improve the interference immunity from undesired signals such as wireless local area network （WLAN）.展开更多
文摘目的研究山楂荷叶饮对高脂血症大鼠的作用并探讨其降脂的潜在活性成分及作用靶点。方法建立高脂血症大鼠模型,从血脂水平、体质量、肝脏系数、脂肪质量以及肝脏病理形态变化等方面评价山楂荷叶饮的降脂效果;采用超高效液相色谱-四极杆飞行时间质谱(ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry,UHPLC-QTOF-MS)对山楂荷叶饮中的化学成分进行鉴定,筛选山楂荷叶饮中活性成分与高脂血症的交集靶点,采用STRING数据库对蛋白相互作用网络进行构建与分析,利用Auto Dock Tools软件对活性成分与关键靶点进行分子对接验证。结果山楂荷叶饮能显著降低高脂血症大鼠总胆固醇(total cholesterol,TC)、三酰甘油(triglycerides,TG)和低密度脂蛋白(low-density lipoprotein cholesterol,LDL-C)水平,降低体质量及肝脏指数、附睾脂肪和肾周脂肪质量,改善肝脏组织病理形态、红色脂滴沉积情况。从山楂荷叶饮中共检测鉴定出88个化合物,其中生物碱类27个、黄酮类33个、有机酸类19个、其他类9个。网络药理学分析发现,山楂荷叶饮中金丝桃苷、荷叶碱、槲皮素、乌药碱等10个关键成分可能通过调控10个核心靶点发挥对高脂血症的调节作用。分子对接结果显示,关键成分与核心靶点蛋白结合活性良好。结论山楂荷叶饮可通过改善血脂水平、减少肝脏脂肪堆积等发挥对高脂血症的治疗作用,为山楂荷叶饮降血脂成分和机制的研究及产品的开发提供参考。
基金supported by the Natural Science Foundation of CQ CSTC(CSTC2010DD2412)Chongqing Municipal Science and Technology Commission of Natural Science Foundation Project(KJ100512)the Research Fund Project of Chongqing University of Posts and Telecommunications(A2011-51)
文摘A novel, compact, and highly selective ultra-wideband （UWB） bandpass filter with a narrow notched band is presented. Apart from having a basic structure of a slotline multiple-mode resonator （MMR） and microstrip feed lines, this novel design introduces a cross-coupling between the input and output feed lines to enhance the filter selectivity. The design strictly follows the theory and verified by electromagnetic （EM） simulation and experiments. In addition, the narrow notched band is introduced by embedding a pair of split ring resonators （SRR） in order to reject any undesired existing radio signals that may interfere with the Federal Communications Commission （FCC）-defined UWB band. By changing the structural parameters of SRR, it can be easily tuned to any desired frequency. This filter can be integrated in UWB communication systems and efficiently improve the interference immunity from undesired signals such as wireless local area network （WLAN）.
