国际原油价格波动对中国行业指数的溢出效应

运用2015年1月-2020年2月的日数据,将原油价格波动作为外生变量,通过灰色关联模型筛选出与WTI原油期货价格关联程度较高的行业指数,从收益率和波动率两个层面,分别采用VAR-X模型和Asymmetric BEKK-X模型实证分析了国际原油价格波动对上证行业指数的均值溢出效应和波动溢出效应。研究表明:WTI原油价格波动对上证金融地产和原材料行业指数提供显著的均值溢出渠道,上证金融地产行业指数对上证原材料行业指数存在显著的单向均值溢出效应;WTI原油价格波动率对上证金融地产行业指数提供显著的波动溢出渠道,上证金融地产行业指数与原材料行业指数之间存在双向的波动溢出效应;上证金融地产行业指数不仅自身存在非对称效应,而且对上证原材料行业指数存在单向的非对称波动溢出效应。

The association between admission systolic blood pressure and 1-year mortality in patients with non-ST-segment elevation acute coronary syndrome

Background In patients with acute coronary syndrome（ACS）, lower admission systolic blood pressure（SBP）levels infer a worse prognosis. However, the predictive potential of admission SBP on 1-year mortality has not fully elucidated in patients with non-ST-segment elevation ACS（NSTEACS）. Methods We enrolled 1325 patients to investigate the association between admission SBP in patients hospitalized for NSTEACS. We analyzed the association between admission SBP and 1-year mortality. Admission SBP was categorized as low（〈110 mm Hg）, normal（110-140 mm Hg）, high（141-160 mm Hg）, and very high（〉160 mm Hg）. Results Compared with patients with normal admission SBP, those with low SBP had a significantly increased hazard ratios（HRs） for 1-year mortality of 3.03（P〈0.05）, while patients with high and very high admission SBP had no significantly increased HRs for 1-year mortality. Conclusion Low admission SBP, but not elevated admission SBP, is a strong independent predictor of 1-year mortality in patients with NSTEACS.