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This paper uses the test proposed by Generalized Supremum Augmented Dickey-Fuller to identify whether there are multiple bubbles in copper price. The empirical results show that base on market fundamentals, there are seven bubbles existed from January 1980 to March 2023. Through analyses, the first two bubbles can be explained by the demand from Japan by the industry concentration and persistent supply constraint. The third to sixth bubbles are mainly negatively impacted by the global financial crisis and growing demand of China. The last bubble is caused by the economic recovery from Covid-19. The logit regression has stated that aluminum price, copper production, all metals index and GDP have a positive impact on copper bubbles, while China's copper imports and precious metals price negatively explains copper bubbles. The main contributions are the investigation of the copper price bubbles, its determinants and the different technique of GSADF to detect copper price bubbles. Furthermore, it provides helpful information for those investors to make reasonable investment decisions and thus, avoid potential price risk. [ABSTRACT FROM AUTHOR]

Purpose: Patient-reported outcomes after surgery and anaesthesia have recently attracted attention. A recent systematic review and a consensus guideline recommend that patients' recovery can be adequately measured using the quality of recovery-15 (QoR-15) during the perioperative period; however, the Japanese version of the QoR-15 (QoR-15J) is not available. We aimed to translate the QoR-15 into Japanese and assess its validity., Methods: After translating into Japanese, 205 patients who underwent various types of surgery under general anaesthesia were enrolled in the study. QoR-15J was evaluated before surgery and 24 h and 48 h after surgery. Additionally, 30 patients answered the QoR-15J at 25 h after surgery. We assessed the feasibility, reliability, validity, and responsiveness of the QoR-15J., Results: One patient who did not undergo surgery and two patients who were discharged within 24 h were excluded. One hundred and eighty-seven patients answered the QoR-15J at 24 h after surgery (completion rate, 92.6%) and 183 patients with complete data were included in the final analysis. The Cronbach's alpha coefficient for internal reliability and Spearman rank correlation coefficient for test-retest reliability were 0.84 and 0.91, respectively. The Cohen effect size for all items was 1.42., Conclusions: QoR-15 was translated into Japanese and the Japanese version's validity was assessed in patients undergoing various types of surgery under general anaesthesia. Our results suggest that QoR-15J is feasible, reliable, valid, and responsive.