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Multi-port DC power electronic transformer (PET) is a core equipment for achieving transformation of different voltage levels and flexible interconnection of different DC buses in a DC distribution system. It is capable of bidirectional energy flow, flexible regulation of power flow, port fault isolation, and other functions. A new five-port DC transformer topology based on soft switching technology is proposed in this paper. In this topology, different DC voltage levels can be interconnected efficiently, such as 20 kV, 750 V, ±375 V, and 300 to 500 V adjustable. The control of each port is simple and flexible. The output voltage is stable, and they are independent of each other, which can improve the system reliability. The topology of the proposed multi-port DC transformer is introduced in detail. The working principle, control strategy, and parameter design method of the transformer are analyzed. Simulations and experimental results are provided to validate the theoretical analysis. [ABSTRACT FROM AUTHOR]

In this paper, the Mg Ca alloy hydride (MCH)-salt composites were prepared by ball milling and characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The objective of this work was to investigate the effects of the synthesis parameters, including salt amounts and compositions, on the hydrogen generation performances in terms of conversion rate and kinetics, and thus to improve the hydrolysis property of MCH. It was found that the xMCH-MgCl 2 (x = 5, 10, 15 and 20) composites generate less hydrogen than MCH. This abnormal phenomenon may be due to the common ion effect of Mg 2+ in the hydrolysis processes. The 10MCH-MgCl 2 composite milled for 0.5 h displays the lowest hydrogen yield of 962 mL per gram of the composite at 25 °C, and has slower hydrogen generation rate (692 mL g −1 in 10 min) than MCH (722 mL g −1 in 10 min). At the same conditions, compared with MCH, the xMCH-CaCl 2 (x = 5, 10, 15 and 20) composites exhibit better hydrogen generation performances. Especially, 15MCH-CaCl 2 has a hydrogen yield of 1141 mL g −1 (composite) . [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to conduct a systematic review of the literature to identify and summarize the existing evidence regarding ERAS failure and related risk factors after hepatic surgery. The objective was to provide physicians with a better understanding of these factors so that they can take appropriate action to minimize ERAS failure and improve patient outcomes., Method: A literature search of the PubMed MEDLINE, OVID, EMBASE, Cochrane Library, and Web of Science was performed. The search strategy involved terms related to ERAS, failure, and hepatectomy., Result: A meta-analysis was conducted on four studies encompassing a total of 1,535 patients, resulting in the identification of 20 risk factors associated with ERAS failure after hepatic surgery. Four of these risk factors were selected for pooling, including major resection, ASA classification of ≥3, advanced age, and male gender. Major resection and ASA ≥ 3 were identified as statistically significant factors of ERAS failure., Conclusion: The comprehensive literature review results indicated that the frequently identified risk factors for ERAS failure after hepatic surgery are linked to operative and anesthesia factors, including substantial resection and an American Society of Anesthesiologists score of 3 or higher. These insights will assist healthcare practitioners in taking prompt remedial measures. Nevertheless, there is a requirement for future high-quality randomized controlled trials with standardized evaluation frameworks for ERAS programs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ren, Wu, Li, Li and Zeng.)