Search

In response to challenges such as the subtle early fault indications and the fluctuating harmonic content in power systems affecting diagnostic accuracy， this paper presents a novel method for analyzing and diagnosing inter-turn short circuit faults in dry-type air-core reactors， taking into consideration the influence of harmonic voltages. Addressing three distinct operating conditions such as normal reactor operation， early-stage arc-type inter-turn short circuits， and mid-to-late-stage metal fusion-type inter-turn short circuits， the paper analyzes the operational characteristics of both series and parallel reactors under fault conditions to identify specific early fault indicators for inter-turn short circuits in each configuration. Additionally， the paper establishes a simulation model for inter-turn short circuit faults in reactors that accounts for harmonic voltage effects and analyzes the variation in electrical characteristics of series and parallel reactors under various operating conditions. Subsequently， it proposes a diagnostic method based on the current harmonic ratio for series reactor faults and another method based on the active power ratio for parallel reactor faults. To validate the effectiveness of the proposed method， the paper constructs an experimental test platform for inter-turn faults in series and parallel reactors and conducts experiments to confirm its correctness and efficacy.

The insulation performance of transformer bushings is a crucial aspect that directly affects the safe operation of equipment. To diagnose the insulation status of transformer bushings and mitigate the impact of small-sample imbalanced data on diagnostic results, a particle swarm optimization combined with back propagation neural network (PSO-BPNN) and adaptive synthetic sampling (ADASYN) method are employed to fault diagnosis of transformer bushing. Initially, historical fault data of transformer bushings are gathered, and a sample set of dissolved gases in transformer oil with distinct fault categories is established. The ADASYN algorithm is used to synthesize the minority class samples in the original data, which allowed for obtaining balanced fault data. The balanced dissolved gases in oil served as the model input, and the fault status is used as the label output to diagnose the transformer bushings using the PSO-BPNN model. To diagnose the bushings under the original sample set, the back propagation neural network (BPNN), genetic combined with back propagation neural network (G-BPNN), cuckoo search combined with back propagation neural network (CS-BPNN), and PSO-BPNN models are used. The results reveal that the PSO-BPNN model based on ADASYN balanced data exhibited the highest accuracy among the various models for fault diagnosing the insulation status of transformer bushings. This approach effectively mitigate the impact of small sample imbalanced data on diagnostic results, and provide an effective method for assessing the insulation performance of transformer bushings.

Context: Diabetic retinopathy (DR) is a common complication of diabetes mellitus (DM). Circular RNAs (circRNAs) act as key regulators of DR development by regulating inflammation and angiogenesis. Objective: This study aimed to elucidate the function and mechanism of hsa_circ_0000047 in DR. Materials and methods: High glucose (HG) was used to induce human retinal microvascular endothelial cells (hRMECs) to construct a DR model in vitro. Qualitative real-time polymerase chain reaction (qRT-PCR) or western blotting were used to detected the levels of hsa_circ_0000047, miR-6720-5p, and CYB5R2 in DR and HG-indeced hRMECs. Cell functional experiments were performed to detect the change of viability, inflammation, migration, invasion, and angiogenesis of HG-induced hRMECs. Besides, the correlation between miR-6720-5p and hsa_circ_0000047/CYB5R2 was confirmed by luciferase assay and Pearson correlation analysis. Results: hsa_circ_0000047 and CYB5R2 were downregulated in DR, whereas miR-6720-5p was upregulated in DR. Cell functional experiments showed that hsa_circ_0000047 overexpression restrained viability, inflammation, migration, invasion, and angiogenesis of HG-induced hRMECs. Regarding mechanism, hsa_circ_0000047 could sponge miR-6720-5p to regulate CYB5R2 expression in hRMECs. Additionally, CYB5R2 knockdown reversed the effects of hsa_circ_0000047 overexpression on HG-induced hRMECs. Conclusion: Our study revealed that hsa_circ_0000047 alleviated inflammation and angiogenesis in HG-induced hRMECs by targeting the miR-6720-5p/CYB5R2 axis, which may be a novel biomarker for DR therapy. [ABSTRACT FROM AUTHOR]

Utilizing observational data from the Xiamen radar station during the warm season of 2015–2018 (May to September), this study employs a convective storm identification algorithm to statistically analyze the spatiotemporal distribution, diurnal propagation, and seasonal variability of convective storms over the southeastern coast of China. Key findings include: (1) Significant monthly variations in convective storm frequency, with peaks in August over land areas of Zhangzhou and Xiamen's northwest, and offshore southeast of Xiamen. Seasonal circulation patterns, particularly the subtropical high and northern high-level troughs, drive these variations. (2) Large-scale convective storms are most frequent, while small-scale ones are less common. Mid-deep convective storms dominate, particularly in southern Zhangzhou and southwestern mountainous Quanzhou, whereas shallow convective storms are rare and scattered. High-frequency areas correlate with higher terrain, underscoring the influence of topography on storm occurrence and development. (3) Hovmöller plots reveal a bimodal diurnal pattern in propagation of storms for July and August, with peaks in the daytime and late night. Daytime storms propagate from coastal to higher terrain areas, while nighttime storms maybe driven by enhanced vertical wind shear. These findings enhance the understanding of convective storms in the region and highlight the crucial role of the circulation background, terrain, and prevailing wind directions in the spatiotemporal characteristics of warm season convective storms in southeastern China. [ABSTRACT FROM AUTHOR]

With the increasing demand for transportation construction in coastal areas, tunnel safety research is becoming increasingly important. Previous studies take less account of the nonlinear wave and current action under the sloping seabed terrain. Furthermore, there are few researches on the additional deformation of shield tunnel lining caused by wave‐current dynamic pressure. In this paper, according to the interaction theory of Stokes third‐order nonlinear wave and uniform current and Biot's dynamic consolidation equation, the excess pore pressure response of sloping pure seabed under the wave‐current action is obtained. The excess pore pressure reflected by the tunnel is acquired using the seepage continuity condition on the permeable lining surface. Considering the residual excess pore pressure caused by the cumulative effect under the cyclic action of seepage force. Then the distribution law of seepage pore pressure around the shield tunnel in the sloping seabed under the wave‐current action is obtained based on the superposition principle. The displacement response of tunnel lining during the long‐term service period is obtained by combining the exponential decay model. Moreover, the accuracy of theoretical analysis is verified by experimental monitoring data and numerical simulation, and the hydraulic parameters, seabed parameters and tunnel parameters are analyzed. [ABSTRACT FROM AUTHOR]

Background: Lung metastasis is the primary cause of breast cancer-related mortality. Neutrophil extracellular traps (NETs) are involved in the progression of breast cancer. However, the mechanism of NET formation is not fully understood. This study posits that tumor cell-released autophagosomes (TRAPs) play a crucial role in this process., Methods: TRAPs were isolated from breast cancer cell lines to analyze their impact on NET formation in both human and mouse neutrophils. The study used both in vitro and in vivo models, including Toll-like receptor 4 (TLR4 - / - ) mice and engineered breast cancer cell lines. Immunofluorescence, ELISA, Western blotting, RNA sequencing, and flow cytometry were employed to dissect the signaling pathways leading to NET production and to explore their immunosuppressive effects, particularly focusing on the impact of NETs on T-cell function. The therapeutic potential of targeting TRAP-induced NETs and their immunosuppressive functions was evaluated using DNase I and αPD-L1 antibodies. Clinical relevance was assessed by correlating circulating levels of TRAPs and NETs with lung metastasis in patients with breast cancer., Results: This study showed that TRAPs induced the formation of NETs in both human and mouse neutrophils by using the high mobility group box 1 and activating the TLR4-Myd88-ERK/p38 signaling axis. More importantly, PD-L1 carried by TRAP-induced NETs inhibited T-cell function in vitro and in vivo, thereby contributing to the formation of lung premetastatic niche (PMN) immunosuppression. In contrast, Becn1 KD-4T1 breast tumors with decreased circulating TRAPs in vivo reduced the formation of NETs, which in turn attenuated the immunosuppressive effects in PMN and resulted in a reduction of breast cancer pulmonary metastasis in murine models. Moreover, treatment with αPD-L1 in combination with DNase I that degraded NETs restored T-cell function and significantly reduced tumor metastasis. TRAP levels in the peripheral blood positively correlated with NET levels and lung metastasis in patients with breast cancer., Conclusions: Our results demonstrate a novel role of TRAPs in the formation of PD-L1-decorated NETs, which may provide a new strategy for early detection and treatment of pulmonary metastasis in patients with breast cancer., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: Minimally invasive spinal trauma surgery includes percutaneous pedicle screw fixation and miniature open anterolateral retractor-based approaches, which can improve surgical outcomes by reducing blood loss, operative time, and postoperative pain. Therefore, this study aimed to evaluate the effect of minimally invasive surgery on pain scores, functional recovery, and postoperative complications in patients with spinal trauma., Methods: This retrospective study included 100 spinal trauma patients treated in Suzhou Hospital of Integrated Traditional Chinese and Western Medicine between May 2019 and May 2022. Patients who underwent traditional open surgery were included in the traditional group, and those who received percutaneous pedicle screw internal fixation combined with posterior minimally invasive small incision decompression were included in the research group, each comprising 50 patients. The effectiveness of these two surgical approaches was determined by assessing their outcome measures, including surgery-related indices, postoperative pain, spinal morphology, functional recovery, and postoperative complications., Results: Minimally invasive surgery was associated with significantly shorter surgical wounds, length of hospital stay, operative time, and postoperative time-lapse before off-bed activity, and less intraoperative hemorrhage volume and postoperative drainage volume compared to open surgery (p < 0.001). Compared to open surgery, patients with minimally invasive surgery showed significantly lower visual analogue scale (VAS) scores at 3 days, 3 months, and 6 months after surgery and lower Oswestry dysfunction index (ODI) at 7 days and 3 months after surgery (p < 0.05). Furthermore, the difference in the spine morphology between the two arms did not achieve statistical significance (p > 0.05). Additionally, minimally invasive surgery resulted in a significantly lower incidence of postoperative complications than open surgery (p < 0.05)., Conclusions: Minimally invasive surgery causes less surgical damage for patients with spinal trauma, improves surgery-related indexes, alleviates postoperative pain, and provides better morphological and functional recovery of the spine.