Objective:To determine the predictive value of P2/MS in patients with chronic HBV-related cirrhosis, and to predict high-risk esophageal varices, and obtain a cut-off value.Methods:A total of 412 patients with HBV-rel...Objective:To determine the predictive value of P2/MS in patients with chronic HBV-related cirrhosis, and to predict high-risk esophageal varices, and obtain a cut-off value.Methods:A total of 412 patients with HBV-related cirrhosis who were admitted to our hospital between August 2014 and August 2017 were retrospectively evaluated. A diagnosis of cirrhosis was made with standard laboratory, radiological and physical examination findings. According to these evaluations, esophageal varices were classified as small, medium and large. For all obtained data, P2/MS was calculated. Two threshold values (P2/MS<11 and P2/MS>25) were considered in predicting the presence of high-risk EVs during recording. And the optimal cut-off value of the P2/MS index was determined for high-risk esophageal varices in patients with chronic viral hepatitis B.Results:A total of 375 patients who met the inclusion criteria were included in the study. When the P2/MS index was compared with other noninvasive tests, the mean and median P2/MS scores were respectively 54.17 and 33.25. The P2/MS value of the patients without esophageal varices was higher than that of the patients with esophageal varices. When these results were evaluated, the higher the score, the lower the risk of varices. We obtained a positive predictive value of 93.80% [95%CI(80.20-98.70)] when the cut-off value of P2/MS was taken as <11, and obtained a negative predictive value of 94.30% [95%CI(86.20-98.20%)] when the cut-off value of P2/MS was taken as >25.Conclusions:We could predict the patients with high-risk esophageal varices within this group at a extremely good rate. We also compared the results of this test with other non-invasive tests and achieved successful results. We have shown that P2/MS can be used in order to optimally select patients for endoscopic screening and prevent all of the expensive and unnecessary procedures safely.展开更多
为应对配电网络低碳化运行的挑战,并充分挖掘系统中分布式资源的灵活调控潜力,文中构建一种基于电碳综合边际定价的虚拟电厂(virtual power plant,VPP)双层点对点(peer-to-peer,P2P)交易模型。上层由配电网运营商(distribution system o...为应对配电网络低碳化运行的挑战,并充分挖掘系统中分布式资源的灵活调控潜力,文中构建一种基于电碳综合边际定价的虚拟电厂(virtual power plant,VPP)双层点对点(peer-to-peer,P2P)交易模型。上层由配电网运营商(distribution system operator,DSO)建立基于碳排放流(carbon emission flow,CEF)技术的碳感知最优潮流模型,在此基础上计算出电碳综合边际价格,DSO可利用该价格信号协调VPP低碳调度。下层组建多VPP合作联盟,可将电动汽车规模化整合并引入碳信号引导的电动汽车灵活调度机制,建立基于贡献度的非对称纳什议价交易模型,各VPP在价格信号的引导下平衡个体与联盟利益,制定生产与交易的最优策略。然后,采用自适应交替方向乘子法(adaptive-scaling alternating direction method of multipliers,AS-ADMM)对模型进行求解,解决变量耦合导致的收敛速度问题。最后,采用改进的IEEE 33节点配电系统进行仿真验证。案例分析结果表明,所提交易模型可以通过提高分布式能源利用效率并优化负荷分布,在降低VPP运营成本的同时减少配电网碳排放。展开更多
P2型层状过渡金属氧化物(P2-Na_(x)TMO_(2))因其优异的循环稳定性和倍率性能,成为钠离子电池正极材料的有力候选者。然而,其在高电压下的不可逆相变和固有低理论容量问题,阻碍了实际应用。本研究工作提出高熵策略与双相结构的协同设计...P2型层状过渡金属氧化物(P2-Na_(x)TMO_(2))因其优异的循环稳定性和倍率性能,成为钠离子电池正极材料的有力候选者。然而,其在高电压下的不可逆相变和固有低理论容量问题,阻碍了实际应用。本研究工作提出高熵策略与双相结构的协同设计来克服这些挑战。通过在P2相高熵基体中引入O3相,构建新型P2/O3双相高熵层状氧化物Na_(0.70)Ni_(0.25)Mn_(0.35)Co_(0.15)Fe_(0.05)Ti_(0.20)O_(2)(简称Na_(0.70)NMCFT)。其中,高熵设计通过构型熵稳定效应有效抑制P2相的不可逆相变,而O3相则通过协同作用弥补容量不足并提升循环稳定性。此外,双相组分之间的相互作用进一步促进P2-O3与P2-P3相变的高度可逆性。Na_(0.70)NMCFT在1C倍率下的初始放电容量为102.08 mAhg^(-1),200次循环后容量保持率达88.15%,表明具有优异的循环稳定性。更重要的是,即使在10C的高倍率下,Na_(0.70)NMCFT仍能提供85.67 mAh g^(-1)的初始放电比容量,并在1000次循环后容量保持率达70%。本工作证实双相高熵设计在提升钠离子电池正极性能中的关键作用,为开发先进钠离子电池正极材料提供了新思路。展开更多
文摘Objective:To determine the predictive value of P2/MS in patients with chronic HBV-related cirrhosis, and to predict high-risk esophageal varices, and obtain a cut-off value.Methods:A total of 412 patients with HBV-related cirrhosis who were admitted to our hospital between August 2014 and August 2017 were retrospectively evaluated. A diagnosis of cirrhosis was made with standard laboratory, radiological and physical examination findings. According to these evaluations, esophageal varices were classified as small, medium and large. For all obtained data, P2/MS was calculated. Two threshold values (P2/MS<11 and P2/MS>25) were considered in predicting the presence of high-risk EVs during recording. And the optimal cut-off value of the P2/MS index was determined for high-risk esophageal varices in patients with chronic viral hepatitis B.Results:A total of 375 patients who met the inclusion criteria were included in the study. When the P2/MS index was compared with other noninvasive tests, the mean and median P2/MS scores were respectively 54.17 and 33.25. The P2/MS value of the patients without esophageal varices was higher than that of the patients with esophageal varices. When these results were evaluated, the higher the score, the lower the risk of varices. We obtained a positive predictive value of 93.80% [95%CI(80.20-98.70)] when the cut-off value of P2/MS was taken as <11, and obtained a negative predictive value of 94.30% [95%CI(86.20-98.20%)] when the cut-off value of P2/MS was taken as >25.Conclusions:We could predict the patients with high-risk esophageal varices within this group at a extremely good rate. We also compared the results of this test with other non-invasive tests and achieved successful results. We have shown that P2/MS can be used in order to optimally select patients for endoscopic screening and prevent all of the expensive and unnecessary procedures safely.
文摘为应对配电网络低碳化运行的挑战,并充分挖掘系统中分布式资源的灵活调控潜力,文中构建一种基于电碳综合边际定价的虚拟电厂(virtual power plant,VPP)双层点对点(peer-to-peer,P2P)交易模型。上层由配电网运营商(distribution system operator,DSO)建立基于碳排放流(carbon emission flow,CEF)技术的碳感知最优潮流模型,在此基础上计算出电碳综合边际价格,DSO可利用该价格信号协调VPP低碳调度。下层组建多VPP合作联盟,可将电动汽车规模化整合并引入碳信号引导的电动汽车灵活调度机制,建立基于贡献度的非对称纳什议价交易模型,各VPP在价格信号的引导下平衡个体与联盟利益,制定生产与交易的最优策略。然后,采用自适应交替方向乘子法(adaptive-scaling alternating direction method of multipliers,AS-ADMM)对模型进行求解,解决变量耦合导致的收敛速度问题。最后,采用改进的IEEE 33节点配电系统进行仿真验证。案例分析结果表明,所提交易模型可以通过提高分布式能源利用效率并优化负荷分布,在降低VPP运营成本的同时减少配电网碳排放。
文摘P2型层状过渡金属氧化物(P2-Na_(x)TMO_(2))因其优异的循环稳定性和倍率性能,成为钠离子电池正极材料的有力候选者。然而,其在高电压下的不可逆相变和固有低理论容量问题,阻碍了实际应用。本研究工作提出高熵策略与双相结构的协同设计来克服这些挑战。通过在P2相高熵基体中引入O3相,构建新型P2/O3双相高熵层状氧化物Na_(0.70)Ni_(0.25)Mn_(0.35)Co_(0.15)Fe_(0.05)Ti_(0.20)O_(2)(简称Na_(0.70)NMCFT)。其中,高熵设计通过构型熵稳定效应有效抑制P2相的不可逆相变,而O3相则通过协同作用弥补容量不足并提升循环稳定性。此外,双相组分之间的相互作用进一步促进P2-O3与P2-P3相变的高度可逆性。Na_(0.70)NMCFT在1C倍率下的初始放电容量为102.08 mAhg^(-1),200次循环后容量保持率达88.15%,表明具有优异的循环稳定性。更重要的是,即使在10C的高倍率下,Na_(0.70)NMCFT仍能提供85.67 mAh g^(-1)的初始放电比容量,并在1000次循环后容量保持率达70%。本工作证实双相高熵设计在提升钠离子电池正极性能中的关键作用,为开发先进钠离子电池正极材料提供了新思路。
