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With the continuous reduction of chip size, fluxless soldering has brought attention to high-density, three-dimensional packaging. Although fluxless soldering technology with formic acid (FA) atmosphere has been presented, few studies have examined the effect of the Pt catalytic, preheating time, and soldering pad on FA soldering for the Sn-58Bi solder. The results have shown that the Pt catalytic can promote oxidation–reduction and the formation of a large pore in the Sn-58Bi/Cu solder joint, which causes a decrease in shear strength. ENIG (electroless nickel immersion gold) improves soldering strength. The shear strength of Sn-58Bi/ENIG increases under the Pt catalytic FA atmosphere process due to the isolation of the Au layer on ENIG. The Au layer protects metal from corrosion and provides a good contact surface for the Sn-58Bi solder. The shear strength of the Sn-58Bi/ENIG joints under a Pt catalytic atmosphere improved by 44.7% compared to using a Cu pad. These findings reveal the improvement of the shear strength of solder joints bonded at low temperatures under the FA atmosphere. [ABSTRACT FROM AUTHOR]

This paper presents a new additional perturbation control method for suppressing low-frequency oscillation in voltage-mode H-bridge DC-AC inverter. The stability boundary of the H-bridge inverter is investigated from its small-signal averaged model. High input voltage and light load would cause low-frequency oscillation in this system. To this end, a filter-based perturbation control (FBPC) is proposed for eliminating this oscillation, by using an analog filter to extract the unexpected signal and applying it to the control loop. Theoretical results show a larger stability range of the controlled system with the proposed FBPC. The simulation and experiment results show that the proposed controller can control the low-frequency oscillation in H-bridge DC-AC inverter well. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

IGBT power module is the key component of the power electronic converter, but it has the lowest reliability. The junction temperature is the crucial factor which affects power module’s reliability. To some extent, the power handling capability of the converter depends on the thermal stress of the power module. Thermal management is an effective method to improve the reliability of power device, as well as enhance the power capability. For this purpose, this paper introduces the reliability design to the power converter’s traditional compensation controller design for the first time. A new concept of generalized dual-loop controller, which includes temperature control loop and electric power control loop, is proposed. The reliability and stability of the system are both considered, with the help of the hybrid controller, the power converter can operate steadily with higher reliability. The novelty of this paper is to improve the thermal control method of carrier frequency adjustment through experimental implementation during the full life cycle of the converter. The target is to control the temperature variation to be almost a constant value as well as extend the lifetime of the converter. IR sensor is used to measure the chip temperature of the unpackaged IGBT module. The temperature variation and the average temperature are all considered in thermal management, from the reliability improvement point of view. At last, the idea is digital implemented based on a varying load of power inverter system with real-time measurement of the chip’s surface temperature. [ABSTRACT FROM AUTHOR]

Objectives: To identify and classify submucosal tumors by building and validating a radiomics model with gastrointestinal endoscopic ultrasonography (EUS) images., Methods: A total of 144 patients diagnosed with submucosal tumors through gastrointestinal EUS were collected between January 2019 and October 2020. There are 1952 radiomic features extracted from each patient's EUS images. The statistical test and the customized least absolute shrinkage and selection operator regression were used for feature selection. Subsequently, an extremely randomized trees algorithm was utilized to construct a robust radiomics classification model specifically tailored for gastrointestinal EUS images. The performance of the model was measured by evaluating the area under the receiver operating characteristic curve., Results: The radiomics model comprised 30 selected features that showed good discrimination performance in the validation cohorts. During validation, the area under the receiver operating characteristic curve was calculated as 0.9203 and the mean value after 10-fold cross-validation was 0.9260, indicating excellent stability and calibration. These results confirm the clinical utility of the model., Conclusions: Utilizing the dataset provided curated from gastrointestinal EUS examinations at our collaborating hospital, we have developed a well-performing radiomics model. It can be used for personalized and non-invasive prediction of the type of submucosal tumors, providing physicians with aid for early treatment and management of tumor progression., Competing Interests: None., (© 2024 The Authors. DEN Open published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)

Introduction: YiYiFuZi powder (YYFZ) is a classical formula in Chinese medicine, which is commonly used clinically for the treatment of Chronic Heart Disease (CHD), but it's pharmacological effects and mechanism of action are currently unclear. Methods: An adriamycin-induced CHD model rat was established to evaluate the pharmacological effects of YYFZ on CHD by the results of inflammatory factor level, histopathology and echocardiography. Metabolomic studies were performed on rat plasma using UPLC-Q-TOF/MS to screen biomarkers and enrich metabolic pathways; network pharmacology analysis was also performed to obtain the potential targets and pathways of YYFZ for the treatment of CHD. Results: The results showed that YYFZ significantly reduced the levels of TNF- α and BNP in the serum of rats, alleviated the disorder of cardiomyocyte arrangement and inflammatory cell infiltration, and improved the cardiac function of rats with CHD. The metabolomic analysis identified a total of 19 metabolites, related to amino acid metabolism, fatty acid metabolism, and other metabolic pathways. Network pharmacology showed that YYFZ acts through PI3K/Akt signaling pathway, MAPK signaling pathway and Ras signaling pathway. Discussion: YYFZ treatment of CHD modulates blood metabolic pattern and several protein phosphorylation cascades but importance specific changes for therapeutic effect require further studies., Competing Interests: Author MQ was employed by TIPRHUYA Advancing Innovative Medicines Ltd. The remaining 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 Wang, Li, Qi, Li, Zhang, Wang, Wu, Shu, Fan, Li and Li.)