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Metasurface-based optical beam scanning devices are gaining attention in optics and photonics for their potential to revolutionize light detection and ranging systems. However, achieving anomalous refraction with perfect efficiency (>99%) remains challenging, limiting the efficiency and field of view (FOV) of metasurface-based optical beam scanning devices. Here, we introduce a paradigm for achieving perfect anomalous refraction by augmenting longitudinal degrees of freedom arousing a multiple scattering process to optimize symmetry breaking. An all-dielectric quasi-three-dimensional subwavelength structure (Q3D-SWS), composed of a purposely designed multilayer film and a dielectric metasurface separated by a spacer, is proposed to eliminate reflection loss and spurious diffraction, achieving >99% anomalous refraction efficiency. By independently rotating two cascaded Q3D-SWSs, we experimentally showcase half-space optical beam scanning, achieving a FOV of 144° × 144°, with a maximum efficiency exceeding 86%. Our results open new avenues for high-efficiency metasurfaces and advances applications in light detection and ranging systems. The authors introduce an exciting paradigm for achieving perfect anomalous refraction using an all-dielectric quasi–three-dimensional subwavelength structure and demonstrate half-space beam scanning.

Background The objective of this study was to explore the correlation between statin administration in the intensive care unit (ICU) setting and the in-hospital mortality risk of patients suffering from sepsis-induced coagulopathy (SIC). Methods Utilizing a retrospective cohort study design, this investigation collected data from the Medical Information Mart for Intensive Care (MIMIC)-IV spanning 2008 to 2019. The diagnosis of SIC was established based on a SIC score of 4 or above. Statin usage during the ICU period was extracted from the prescription records based on the keywords of statin medications. The primary endpoint analyzed was the in-hospital mortality within the ICU, characterized by any death occurring during the ICU admission. Results During the follow-up, which had a median duration of approximately 7.28 days, 18.19% of the 4,777 SIC patients died in the ICU. Statin was linked with a decrease in the risk of in-hospital mortality for SIC patients in the ICU [hazard ratio (HR): 0.73, 95% confidence interval (CI): 0.60–0.89, P  = 0.002]. Relative to rosuvastatin, the use of atorvastatin (HR: 0.54, 95% CI: 0.34–0.85, P  = 0.008) or simvastatin (HR: 0.55, 95% CI: 0.33–0.92, P  = 0.024), as well as combinations of multiple statins (HR: 0.36, 95% CI: 0.15–0.86, P  = 0.022), was associated with a reduction in ICU in-hospital mortality risk. Subgroup analysis also suggested that the use of atorvastatin, simvastatin, or a combination of statins had an advantage over rosuvastatin in reducing ICU in-hospital mortality in SIC patients older than 65 years of age or SIC patients with respiratory failure or cardiogenic shock (all P  < 0.05). Conclusion The present study supports the potential benefits of statin use in mortality in SIC patients during ICU stays. The study encourages clinicians to consider the benefits of statins and supports the ongoing exploration of statins for enhanced outcomes in critical care settings.

In a complex underwater environment, finding a viable, collision-free path for an autonomous underwater vehicle (AUV) is a challenging task. The purpose of this paper is to establish a safe, real-time, and robust method of collision avoidance that improves the autonomy of AUVs. We propose a method based on active sonar, which utilizes a deep reinforcement learning algorithm to learn the processed sonar information to navigate the AUV in an uncertain environment. We compare the performance of double deep Q-network algorithms with that of a genetic algorithm and deep learning. We propose a line-of-sight guidance method to mitigate abrupt changes in the yaw direction and smooth the heading changes when the AUV switches trajectory. The different experimental results show that the double deep Q-network algorithms ensure excellent collision avoidance performance. The effectiveness of the algorithm proposed in this paper was verified in three environments: random static, mixed static, and complex dynamic. The results show that the proposed algorithm has significant advantages over other algorithms in terms of success rate, collision avoidance performance, and generalization ability. The double deep Q-network algorithm proposed in this paper is superior to the genetic algorithm and deep learning in terms of the running time, total path, performance in avoiding collisions with moving obstacles, and planning time for each step. After the algorithm is trained in a simulated environment, it can still perform online learning according to the information of the environment after deployment and adjust the weight of the network in real-time. These results demonstrate that the proposed approach has significant potential for practical applications.

In new distribution systems with high penetration of renewable energy, inverter-based sources exhibit significant differences in fault characteristics compared to traditional power sources due to the absence of a constant electromotive force and their operation under nonlinear control links, rendering conventional fault current calculation methods inadequate. To address these challenges, a full-time-domain analysis-based method for modelling and calculating fault transient characteristics is proposed. First, a dynamic model of inverter-based sources accounting for current loop saturation effects is established, and phase plane analysis is employed to resolve nonlinear control regions. On this basis, a full-time-domain fault current calculation method is proposed, wherein the steady-state operating point after a fault is determined by iteratively solving the network node voltage equations. By integrating control strategies and derived transient differential equations, the fault current expression across the full-time-domain scope is formulated. Furthermore, a multi-objective optimization control strategy is proposed to achieve effective fault current suppression, and an improved Simulated Annealing-Particle Swarm Optimization (SA-IPSO) hybrid algorithm is adopted for efficient solution. Finally, SIMULINK-based simulation experiments validate the accuracy and effectiveness of the proposed method in transient characteristic analysis and current suppression.

The global concern over bullying has spurred extensive research among scholars on both traditional bullying and cyberbullying. This study aims to further explore the intrinsic connection between traditional bullying and cyberbullying, as well as the underlying mechanisms linking the two. A comprehensive survey was conducted among 705 young students from various universities across China. Through the analysis of questionnaire data, this study further investigated how moral disengagement, social support, and gender function in the relationship between being a victim of traditional bullying and perpetrating cyberbullying. The findings revealed that victims of traditional bullying are at a higher risk of engaging in cyberbullying. The analysis indicated that moral disengagement plays a mediating role in the relationship between traditional bullying victimization and cyberbullying perpetration. Social support acts as a moderator, such that the relationship between traditional bullying victimization and cyberbullying perpetration is stronger when the level of social support is higher. Additionally, gender moderates the relationship from moral disengagement to cyberbullying perpetration. The results of this study underscore the necessity for cyberbullying prevention programs to focus on victims of traditional bullying to prevent the escalation from traditional bullying to cyberbullying.

Mat foundations have been widely used as foundations of mobile offshore platforms such as jack-up rigs and installation platforms. Throughout the service period, the mat bears coupled multi-dimensional loads transferred from the superstructure and directly from the environment. Evaluating the bearing capacity of the mat is the premise of offshore platform design. However, there are few studies on the bearing capacity of commonly used irregularly shaped mats under multi-dimensional load conditions. Looking at two types of A-shaped mats on cohesive soil, uniaxial bearing capacities are calculated using the finite element method (FEM) in this study. The centrifuge test was performed to verify the FEM results. Effects of the length-to-width aspect ratio of the foundation on bearing capacities are discussed. The V-H , V-M , and V-H-M failure envelopes of mats with unlimited and zero tension interfaces are obtained. Studies have shown that the uniaxial bearing capacities change monotonously with aspect ratio increases, and that the bearing capacity of a rectangular A-shaped mat is higher than that of a trapezoidal A-shaped mat. The V-H-M envelope with unlimited tension interface condition is ellipsoid-shaped, while that with zero tension interface is scallop-shaped. With the capacity expressions established in the paper, it is possible to quickly check the bearing state of the mat under a given V-H-M load condition, and then assess the safety of the engineering operation.

Background Bronchoscopic resection represents a facilitated alternative option for restoration of airway patency in selected cases. However, the procedure is susceptible to complications arising from severe hemorrhaging. This single-center retrospective pilot study aimed to evaluate the safety and feasibility of bronchial artery embolization (BAE) prior to endobronchial resection in patients with central airway obstruction (CAO). Method Patients with CAO caused by hypervascular tumors with strong enhancement on computed tomography (CT) and/or hemoptysis were included in the study. All neoplasms were excised using argon plasma coagulation during bronchoscopic intervention. Preceding the procedure, selective bronchial artery embolization was conducted to occlude the neoplastic blood supply 48 h in advance. The analysis encompassed an evaluation of hemorrhage severity, reconstruction of airway patency, and associated complications. Results A total of 24 patients (15 males and 9 females) with central airway obstruction were included for analysis, with a mean age of 61 ± 10 years (42–87 years) and followed-up for a median (range) of 26 (20–54) months. The locations of tumor in the airway included lobar bronchus (17/24, 70.8%) and trachea (7/24, 29.2%). The obstruction degree was Grade III in 15 (62.5%) patients and Grade IV in 9(37.5%) patients. Embolization and bronchoscopy tumor resection were successfully performed in all the patients. Procedure-related minor bleeding occurred in 19 (79.2%) patients and moderate bleeding in 5 (20.8%) patients; No severe bleeding occurred. Reconstruction of airway patency with complete response and partial response were seen in 16 (66.7%) patients and 8 (33.3%) patients, respectively, and symptom relief was achieved in all the patients. Complications after BAE, including chest pain (11/24, 45.8%) and abdominal pain (3/24, 12.5%), were alleviated on the next day after receiving supportive therapies. Fever, shivering, and vomiting occurred in 9/24 (37.5%), 4/24 (16.7%), and 3/24 (12.5%) patients, respectively. Spinal cord injury was not observed in this study. Conclusions Bronchoscopic resection of airway tumors following selective bronchial artery embolization represents a potentially safe and viable approach for mitigating severe bleeding during the excision of hypervascular airway tumors. Further validation through a comprehensive prospective study is warranted.

Marine gas hydrates accumulate primarily in coarse-grained, high-permeability layers; however, highly saturated natural gas hydrates have been discovered in the fine-grained sediments of Shenhu area, South China Sea（SCS）. This may be explained by key factors, such as the great abundance of foraminifera shells. In this paper, by analyzing the SCS foraminifera structure and performing hydrate formation experiments in the foraminifera shells, the contribution of foraminifera to hydrate accumulation in the SCS was investigated from a microscopic point of view. Simulations of hydrate formation were carried out in both pure SCS foraminifera shells and the host sediments. Pore structures in typical foraminifera were studied by use of micro-focus X-ray computed tomography（CT） and scanning electron microscopy（SEM）. Hydrate growth and occurrence characteristics in the foraminifera shells were observed in-situ. The results showed that the presence of foraminifera significantly enhanced the effective porosity of the SCS sediments. Moreover, while the hydrates grew preferentially in the chambers of the coarse-grained foraminifera by adhering to the inner walls of the foraminifera shells, no apparent hydrate accumulation was observed in the fine-grained or argillaceous matrix. These findings provide a basis for further studies on the accumulation mechanism of hydrates and physical properties of hydrate reservoir in the South China Sea.

CH4/CO2 replacement is of great significance for the exploitation of natural gas hydrate resources and CO2 storage. The feasibility of this method relies on our understanding of the CH4/CO2 replacement efficiency and mechanism. In this study, CH4/CO2 replacement experiments were carried out to study the distribution characteristics of CH4 and CO2 in hydrate-bearing sediments during and after replacement. Similar to previously reported data, our experiments also implied that the CH4/CO2 replacement process could be divided into two stages: fast reaction and slow reaction, representing CH4/CO2 replacement in the hydrate-gas interface and bidirectional CH4/CO2 diffusion caused replacement, respectively. After replacement, the CO2 content gradually decreased, and the methane content gradually increased with the increase of sediment depth. Higher replacement percentage can be achieved with higher replacement temperature and lower initial saturation of methane hydrate. Based on the calculation of CO2 consumption amounts, it was found that the replacement mainly took place in the fast reaction stage while the formation of CO2 hydrate by gaseous CO2 and water almost runs through the whole experimental process. Thus, the pore scale CH4/CO2 replacement process in sediments can be summarized in the following steps: CO2 injection, CO2 diffusing into sedimentary layer, occurrence of CH4/CO2 replacement and CO2 hydrate formation, wrapping of methane hydrate by mixed CH4-CO2 hydrate, continuous CO2 hydrate formation, and almost stagnant CH4/CO2 replacement.

This study was conducted to assess the effects of dietary supplementation of coated sodium butyrate (CSB) on the growth performance, serum antioxidant, immune performance, and intestinal microbiota of laying ducks. A total of 120 48-week-old laying ducks were randomly divided into 2 treatment groups: the control group (group C fed a basal diet) and the CSB-treated group (group CSB fed the basal diet + 250 g/t of CSB). Each treatment consisted of 6 replicates, with 10 ducks per replicate, and the trial was conducted for 60 days. Compared with the group C, the group CSB showed a significant increase in the laying rate (p<0.05) of the 53-56 week-old ducks. Additionally, the serum total antioxidant capacity, superoxide dismutase activity and immunoglobulin G level were significantly higher (p<0.05), while the serum malondialdehyde content and tumor necrosis factor (TNF)-a level were significantly lower (p<0.05) in the serum of the group CSB compared to the group C. Moreover, the expression of IL-1b and TNF-a in the spleen of the group CSB was significantly lower (p<0.05) compared to that of the group C. In addition, compared with the group C, the expression of Occludin in the ileum and the villus height in the jejunum were significantly higher in the group CSB (p<0.05). Furthermore, Chao1, Shannon, and Pielou-e indices were higher in the group CSB compared to the group C (p<0.05). The abundance of Bacteroidetes in the group CSB was lower than that in the group C (p<0.05), while the abundances of Firmicutes and Actinobacteria were higher in the group CSB compared to the group C (p<0.05). Our results suggest that the dietary supplementation of CSB can alleviate egg-laying stress in laying ducks by enhancing immunity and maintaining the intestinal health of the ducks.