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For the traditional low voltage ride through control under asymmetrical faults, due to the limited control degrees of freedom, the grid-connected inverter control suffers from the problem of not being able to simultaneously realize the output current negative-sequence component suppression and the DC side voltage double-frequency fluctuation suppression. In this regard, a multiple-objective decoupling control strategy is proposed for low voltage ride through of two-stage grid-connected photovoltaic system under asymmetrical faults. The strategy sets the control objective of the inverter as the negative-sequence component suppression of the output current and gives a reference value calculation method for the inner current loop considering the inverter output current limit and reactive power output demand. The super-capacitor is connected to both ends of the DC bus capacitor through the bidirectional Buck-Boost converter to maintain its voltage stability, and the DC side voltage double-frequency fluctuation is transferred to the super-capacitor side. The simulation results show that under the proposed control strategy, the unbalance between three phases of the inverter is reduced and the output current distortion is improved. The double frequency fluctuation of the DC side voltage is reduced significantly compared with the traditional control method.

Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a new tickborne bandavirus identified in China in 2009 (1), and subsequently in South Korea in 2013 (2), [...]

Objective Develop a novel technique to identify an optimal number of regression units corresponding to a single risk point, while creating risk scoring systems from logistic regression-based disease predictive models. The optimal value of this hyperparameter balances simplicity and accuracy, yielding risk scores of small scale and high accuracy for patient risk stratification. Materials and Methods The proposed technique applies an adapted line search across all potential hyperparameter values. Additionally, DeLong test is integrated to ensure the selected value produces an accuracy insignificantly different from the best achievable risk score accuracy. We assessed the approach through two case studies predicting diabetic retinopathy (DR) within six months and hip fracture readmissions (HFR) within 30 days, involving cohorts of 90 400 diabetic patients and 18 065 hip fracture patients. Results Our scores achieve accuracies insignificantly different from those obtained by existing approaches, reaching AUROCs of 0.803 and 0.645 for DR and HFR predictions, respectively. Regarding the scale, our scores ranged 0-53 for DR and 0-15 for HFR, while scores produced by existing methods frequently spanned hundreds or thousands. Discussion According to the assessment, our risk scores offer simple and accurate predictions for diseases. Furthermore, our new DR score provides a competitive alternative to state-of-the-art risk scores for DR, while our HFR case study presents the first risk score for this condition. Conclusion Our technique offers a generalizable framework for crafting precise risk scores of compact scales, addressing the demand for user-friendly and effective risk stratification tool in healthcare. [ABSTRACT FROM AUTHOR]

As a functional material, polyurethane elastomers have found different applications in a variety of fields such as flexible electronics and smart coatings, but due to the damage during use, they are often endowed with self‐healing properties. However, conventional intrinsically self‐healing polyurethanes often don't balance excellent mechanical and self‐healing properties, so it has become crucial to prepare polyurethane elastomers with excellent self‐healing properties and high mechanical properties. In this study, a self‐healing waterborne polyurethane elastomers (IP‐DTDAx‐BAy‐WPU‐n) was synthesized based on 4, 4‐diaminodiphenyl sulfide (DTDA) boronic acid (BA). The disulfide bond has high motility at low temperatures and induces molecular‐level healing at the damaged interface, contributing to good repair under mild conditions. The borate ester bond limits intermolecular chain slippage and improves the mechanical properties as a dynamic cross‐linking point, while its dynamic reversible effect can synergistically improve the self‐healing ability. The results show that the synthesized elastomer films have good mechanical properties (strength 23.21 MPa, elongation at break 1259.08%, toughness 83.28 MJ m−3), good elastic recovery and self‐healing properties (93%). Furthermore, a composite conductors (IP‐DTDAx‐BAy‐WPU/AgNWs) with self‐healing properties was prepared by compositing AgNWs nanowires with polyurethane elastomers, which laid the foundation for its application in flexible electronic devices and wearable sensing devices. [ABSTRACT FROM AUTHOR]

This article discusses the potential role of the brown dog tick, Rhipicephalus sanguineus, in the transmission of severe fever with thrombocytopenia syndrome virus (SFTSV) in Hainan Island, China. The study found that SFTSV RNA levels increased in female ticks after injection with the virus, and the virus was detected in the eggs and larvae that originated from the infected female ticks. These findings suggest that R. sanguineus may serve as a vector for SFTSV and transmit the virus through transovarial transmission. Further research is needed to fully understand the vector role of R. sanguineus in SFTSV transmission. [Extracted from the article]