背景:近期观察性研究发现局部脂肪量对于椎间盘退变评估有重要意义,而肥胖长期被认为是椎间盘退变的危险因素之一,作为肥胖核心因素的脂肪量在既往研究中与椎间盘退变的因果关系尚不明确。目的:探讨不同分布的脂肪量与椎间盘退变的因果...背景:近期观察性研究发现局部脂肪量对于椎间盘退变评估有重要意义,而肥胖长期被认为是椎间盘退变的危险因素之一,作为肥胖核心因素的脂肪量在既往研究中与椎间盘退变的因果关系尚不明确。目的:探讨不同分布的脂肪量与椎间盘退变的因果关系,以帮助增加对椎间盘退变发病机制的认知及制定预防、治疗及预后的策略。方法:从公开发表的IEU Open GWAS中以强相关性及满足连锁不平衡为条件提取躯干及下肢脂肪量的遗传位点作为工具变量,结合Finn Gen最新第9版数据库中选取椎间盘退变作为结局进行孟德尔随机化分析,通过逆方差加权法、MR-Egger回归、简单中位数法、加权中位数法和加权中值法等回归模型的OR值和95%CI评估躯干及下肢脂肪量与椎间盘退变间的因果关系。使用Cochran’s Q检验评估遗传工具变量的异质性,使用MR-Egger截距检验评估多效性,使用留一法评估作为工具变量的单核苷酸多态性对暴露和结局因果关系影响的敏感性。结果与结论:(1)逆方差加权法检测结果显示,躯干脂肪量与椎间盘退变发病风险呈正向因果关联(OR=1.25,95%CI:1.15-1.35,P<0.001),双下肢脂肪量与椎间盘退变发病风险呈反向因果关联(OR=0.7,95%CI:0.63-0.78,P<0.001;OR=0.69,95%CI:0.62-0.76,P<0.001);(2)MR-Egger截距分析未检测到潜在的水平多效性;(3)MR-PRESSO未检测到偏倚单核苷酸多态性,异质性检验存在,留一法敏感性分析提示分析结果可靠;(4)上述结果证实,躯干脂肪量与椎间盘退变有正向因果关系,随着躯干脂肪量增加,椎间盘退变的风险升高;双下肢脂肪量与椎间盘退变有反向因果关系,即随着双下肢脂肪量增加,椎间盘退变风险降低;脂肪的含量及分布会影响椎间盘退变的发病风险,应给予更多的关注。展开更多
This study proposes an efficient secure routing protocol which considers symmetric and asymmetric links for wireless mesh networks(WMNs). A wireless mesh network is a group of wireless mesh routers and several kinds o...This study proposes an efficient secure routing protocol which considers symmetric and asymmetric links for wireless mesh networks(WMNs). A wireless mesh network is a group of wireless mesh routers and several kinds of wireless devices(or nodes). Individual node cooperates by forwarding packets to each other,allowing nodes to communicate beyond the symmetric or asymmetric links. Asymmetric link is a special feature of WMNs because the wireless transmission ranges of different wireless devices may be different. The asymmetric link enhances WMN coverage. Providing security in WMNs has become an important issue over the last few years. Existing research on this topic tends to focus on providing security for routing and data content in the symmetric link. However, most studies overlook the asymmetric link in these networks. This study proposes a novel distributed routing protocol beyond symmetric and asymmetric links, to guarantee the security and high reliability of the established route in a hostile environment, such as WMNs, by avoiding the use of unreliable intermediate nodes. The routes generated by the proposed protocol are shorter than those in prior works. The major objective of the proposed protocol is to allow trustworthy intermediate nodes to participate in the path construction protocol. The mesh clients out of mesh router wireless transmission range may discover a secure route to securely connect to the mesh router for Internet access via the proposed protocol. The proposed protocol enhances wireless mesh network coverage and assures security.展开更多
文摘背景:近期观察性研究发现局部脂肪量对于椎间盘退变评估有重要意义,而肥胖长期被认为是椎间盘退变的危险因素之一,作为肥胖核心因素的脂肪量在既往研究中与椎间盘退变的因果关系尚不明确。目的:探讨不同分布的脂肪量与椎间盘退变的因果关系,以帮助增加对椎间盘退变发病机制的认知及制定预防、治疗及预后的策略。方法:从公开发表的IEU Open GWAS中以强相关性及满足连锁不平衡为条件提取躯干及下肢脂肪量的遗传位点作为工具变量,结合Finn Gen最新第9版数据库中选取椎间盘退变作为结局进行孟德尔随机化分析,通过逆方差加权法、MR-Egger回归、简单中位数法、加权中位数法和加权中值法等回归模型的OR值和95%CI评估躯干及下肢脂肪量与椎间盘退变间的因果关系。使用Cochran’s Q检验评估遗传工具变量的异质性,使用MR-Egger截距检验评估多效性,使用留一法评估作为工具变量的单核苷酸多态性对暴露和结局因果关系影响的敏感性。结果与结论:(1)逆方差加权法检测结果显示,躯干脂肪量与椎间盘退变发病风险呈正向因果关联(OR=1.25,95%CI:1.15-1.35,P<0.001),双下肢脂肪量与椎间盘退变发病风险呈反向因果关联(OR=0.7,95%CI:0.63-0.78,P<0.001;OR=0.69,95%CI:0.62-0.76,P<0.001);(2)MR-Egger截距分析未检测到潜在的水平多效性;(3)MR-PRESSO未检测到偏倚单核苷酸多态性,异质性检验存在,留一法敏感性分析提示分析结果可靠;(4)上述结果证实,躯干脂肪量与椎间盘退变有正向因果关系,随着躯干脂肪量增加,椎间盘退变的风险升高;双下肢脂肪量与椎间盘退变有反向因果关系,即随着双下肢脂肪量增加,椎间盘退变风险降低;脂肪的含量及分布会影响椎间盘退变的发病风险,应给予更多的关注。
文摘This study proposes an efficient secure routing protocol which considers symmetric and asymmetric links for wireless mesh networks(WMNs). A wireless mesh network is a group of wireless mesh routers and several kinds of wireless devices(or nodes). Individual node cooperates by forwarding packets to each other,allowing nodes to communicate beyond the symmetric or asymmetric links. Asymmetric link is a special feature of WMNs because the wireless transmission ranges of different wireless devices may be different. The asymmetric link enhances WMN coverage. Providing security in WMNs has become an important issue over the last few years. Existing research on this topic tends to focus on providing security for routing and data content in the symmetric link. However, most studies overlook the asymmetric link in these networks. This study proposes a novel distributed routing protocol beyond symmetric and asymmetric links, to guarantee the security and high reliability of the established route in a hostile environment, such as WMNs, by avoiding the use of unreliable intermediate nodes. The routes generated by the proposed protocol are shorter than those in prior works. The major objective of the proposed protocol is to allow trustworthy intermediate nodes to participate in the path construction protocol. The mesh clients out of mesh router wireless transmission range may discover a secure route to securely connect to the mesh router for Internet access via the proposed protocol. The proposed protocol enhances wireless mesh network coverage and assures security.
