昼夜过渡区低频一跳天波中不同模式区分及特性分析

昼夜混合路径条件下低频天波传播特性的研究对导航授时系统中应用模式拓展及低电离层参数反演均具有重要的研究意义.本文以地—电离层中100 kHz载频罗兰-C信号的时域有限差分(Finite Difference Time Domain,FDTD)仿真为前提,基于传统的过零检测和快速傅里叶变换(Fast Fourier Transform,FFT)/逆快速傅里叶变换(Inverse Fast Fourier Transform,IFFT)频谱相除算法,对昼夜混合信道(传播路径为东西取向)中地面接收的一跳天波进行模式区分及特性分析.给出了在白天至夜晚、夜晚至白天两种突变电离层下罗兰-C一跳天波中不同模式随收发距离的变化规律,同时给出了模式干涉区域优势场量的分布情况.结果表明,对于昼夜混合模型,一跳天波中存在来自不同高度及昼夜突跳边界反射的多种模式,基于传统方法检测的幅度相位存在不稳定干涉效应,模式界定困难,而基于FFT/IFFT频谱相除算法能够将主要模式进行细化区分,从而获得更高精度、更平稳的模式特性.

不同炮制工艺鲜竹沥多糖的化学特征及体外抗氧化活性比较

目的:比较鲜竹沥不同炮制品多糖的化学特征,并评估其体外抗氧化活性,为鲜竹沥物质基础研究提供理论依据。方法:分别采用苯酚-硫酸法、改良福林-酚试剂(Lowery)法、高效分子排阻色谱联用蒸发光散射检测器分析法(HPSEC-ELSD)、高效分子排阻色谱联用多角度激光散射与示差折光仪分析法(HPSEC-MALLS-RID)、扫描电子显微镜(SEM)对不同炮制工艺鲜竹沥多糖的化学特征进行多维度比较,采用1,1-二苯基-2-苦基肼基(DPPH)自由基清除能力检测试剂盒评价体外抗氧化活性。结果:干馏、火制和水提鲜竹沥的多糖含量、多糖的糖含量及蛋白含量有明显差异,特别是干馏法鲜竹沥多糖的蛋白含量和HPSEC-ELSD指纹图谱与其他两种炮制品的差异较大;进一步HPSEC-MALLS-RID分析表明,干馏法鲜竹沥多糖色谱峰1的相对分子质量远大于其他炮制品,且相对分子质量分布较其他炮制方法更分散;SEM分析发现,干馏法鲜竹沥多糖的表面及断面较其他炮制品更光滑。体外抗氧化活性检测显示,3种炮制品多糖均有一定的抗氧化活性,其中干馏法鲜竹沥多糖具有最强的抑制活性,水提法次之,火制法最弱。结论:不同炮制工艺不仅影响鲜竹沥多糖的含量,也影响其化学特征及生物活性。研究结果揭示了鲜竹沥多糖的潜在药用价值,同时为多糖作为鲜竹沥炮制工艺的质控指标提供了科学依据。

Study on the mechanism of Fuzi in the treatment of allergic rhinitis based on network pharmacology and experimental validation

Objective:To study the key target genes and signaling pathways in the treatment of Allergic Rhinitis(AR)with Radix Aconiti Lateralis Preparata(aka Fuzi).Methods:The TCMPS and PubChem databases were used to screen the active ingredients and target genes of Fuzi using oral bioavailability and drug similarity as screening conditions,and the GeneCards database was used to screen the target genes of AR.The online tool Venny2.1 was used to screen the target genes of Fuzi for the treatment of Allergic Rhinitis;the STRING database was used to obtain the protein-protein interaction(PPI)network of drug-disease targets,and the key target genes were identified by the MCC algorithm.The potential biological processes and signaling pathways were identified by GO enrichment and KEGG enrichment analysis.Finally,animal experiments were conducted to demonstrate the therapeutic effect ofFuzi on Allergic Rhinitis.Results:The TCMSP,PubChem and GeneCards databases were used to screen the 21 active compound components of Fuzi and 68 potential therapeutic target genes of Fuzi for Allergic Rhinitis.PPI network analysis identified the top ten key target genes,namely:PTGS2,TNF,IL6,AKT1,ALB,STAT3,CCL2,CXCL8,VEGFA and JUN,GO functional and KEGG pathway enrichment analysis showed that the significantly enriched functions and pathways of Fuzi on Allergic Rhinitis were closely related to Allergic Rhinitis.Finally,animal experiments were conducted to verify that Fuzi is effective in the treatment of Allergic rhinitis.Conclusion:Increased expression of IL-6 and TNF-αin nasal mucosal tissues of patients with Allergic Rhinitis was positively correlated with indicators related to the disease activity of AllergicRhinitis.Fuzi ameliorated the inflammatory changes in mice with Allergic Rhinitis by inhibiting the activation of Toll-like signaling pathway in the nasal mucosa and decreasing the expression activity of IL-6 and TNF-α.

任意方向电偶极子在水平分层受限空间中的远区辐射场求解

任意方向电偶极子在分层受限空间中的远区辐射场求解对于分析云闪回击、对潜通信、地波超视距雷达等领域中电磁特性问题具有重要意义.本文基于镜像法和偶极子在自由空间远区辐射场,建立了三层水平受限空间模型,对其间任意取向电偶极子产生的远区辐射场表达式进行了推导,综合考虑了从源点到观测点的直达波及上、下界面的一次反射波影响.在此基础上,比较分析了频率为100 kHz,6 MHz和10 MHz的电偶极子处于地-电离层模型中不同位置时传播的辐射特性.结果显示:对于同一位置辐射源,电偶极子的频率越高,辐射波瓣数目越多;当偶极子源的频率相同时,源点距离下界面越远,辐射波瓣数目亦越多.

树突状细胞与嗜酸性粒细胞在难治性鼻窦炎中的相关性研究

目的:通过检测难治性鼻窦炎鼻黏膜中树突状细胞的表达和嗜酸性粒细胞浸润情况,探究其与难治性鼻窦炎发病的相关性。方法:对30例正常鼻黏膜、30例慢性鼻窦炎组织和30例难治性鼻窦炎组织分别进行组织病理学染色,检测各组嗜酸性粒细胞浸润情况,免疫组化和免疫荧光双标记检测各组CD83和CD11c表达情况,以单因素方差分析进行多组间差异统计,采用Pearson相关分析测各组CD83和CD11c共表达与嗜酸性细胞浸润的相关性。结果:难治性鼻窦炎组织中嗜酸性粒细胞浸润和树突状细胞的免疫标志物CD83和CD11c的阳性表达与另外两组比较均显著增加(P<0.05),通过Pearson相关性分析,各组CD83和CD11c共表达与嗜酸性粒细胞浸润两者呈正相关关系(P<0.05)。结论:难治性鼻窦炎组织中树突状细胞数目明显增多,且与嗜酸性粒细胞的浸润呈正相关关系,表明树突状细胞和嗜酸性粒细胞在难治性鼻窦炎发生及发展中起着相互促进作用,进一步得出树突状细胞参与了难治性鼻窦炎发生、发展过程。