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Ultra-low-frequency vibration is prevalent in many critical research fields. Nevertheless, for ultra-low-frequency vibration signals below 1 Hz, there is currently a lack of a cost-effective and efficient measurement method. A new ultra-low-frequency vibration signal testing method based on the passive radio frequency tag phase is proposed using the Radio Frequency Identification (RFID) sensing method. By employing vibration detection on ultra-low-frequency vibration signals, the effectiveness of the proposed approach across different frequencies is validated while thoroughly considering factors such as measurement range, precision, distance, and occlusion effects. The results indicate that this method can accurately measure ultra-low frequency vibration signals as low as 0.01 Hz, with an average relative error of only less than 1.5% for all measurement results, and the error decreases with increasing detection frequency. For the measurement of a 1 Hz vibration signal, the average relative error is less than 1%. In addition, the measurement accuracy remains unaffected by distance or occlusion. Sensitivity and stability tests are also conducted. Continuous monitoring for 8 hours demonstrates the excellent measurement stability of the proposed method. Finally, a performance comparison has been made with laser displacement sensors commonly used in non-contact ultra-low-frequency measurement methods. The results show that the RFID sensing method can detect lower vibration frequencies and has a larger amplitude measurement range and better environmental adaptability. Overall, for ultra-low-frequency vibration, this method offers advantages such as high precision, passive non-contact operation, non-line-of-sight path monitoring, affordability, and convenience. These attributes render it suitable for extensive application in various engineering scenarios requiring ultra-low-frequency vibration testing. [ABSTRACT FROM AUTHOR]

In this study, we used the Sanya Incoherent Scatter Radar (SYISR) to observe the altitude profiles of traveling ionospheric disturbances (TIDs) during a moderate magnetic storm from 13 to 15 March 2022. Three TIDs were recorded, including two large-scale TIDs (LSTIDs) and one medium-scale TID (MSTID). These LSTIDs occurred during the storm recovery phase, characterized by periods of ~110–155 min, downward phase velocities of 22–60 m/s, and a relative amplitude of 17–25%. A nearly vertical front was noted at ~350–550 km, differing from AGW theory predictions. This structure is more attributed to the combined effects of sunrise-induced electron density changes and pre-sunrise uplift. Moreover, GNSS observations linked this LSTID to high-latitude origins, indicating a connection to polar magnetic storm excitation. However, the second LSTID was observed at lower altitudes (150–360 km) with a higher elevation angle (~17°). This LSTID, observed by the SYISR, was absent in the GNSS data from mainland China and Japan, suggesting a potential local source. The MSTID exhibited a larger relative amplitude of 29–36% at lower altitudes (130–210 km) with severe upward attenuation. The MSTID may be related to atmospheric gravity waves from the lower atmosphere. AGWs are considered to be the perturbation source for this MSTID event. [ABSTRACT FROM AUTHOR]

Patients with locally advanced head and neck squamous cell carcinoma (LA‐HNSCC) have poor survival outcomes. The real‐world efficacy of nimotuzumab plus intensity modulated radiotherapy (IMRT)‐based chemoradiotherapy in patients with LA‐HNSCC remains unclear. A total of 25,442 HNSCC patients were screened, and 612 patients were matched by propensity score matching (PSM) (1:1). PSM was utilized to balance known confounding factors. Patients who completed at least five doses of nimotuzumab were identified as study group. The primary end point was 3‐year overall survival (OS) rate. Log‐rank test examined the difference between two survival curves and Cloglog transformation test was performed to compare survival at a fixed time point. The median follow‐up time was 54.2 (95% confidence interval [CI]: 52.7–55.9) months. The study group was associated with improved OS (hazard ratio [HR] = 0.75, 95% CI: 0.57–0.99, p = 0.038) and progression‐free survival (PFS) (HR = 0.74, 95% CI: 0.58–0.96, p = 0.021). Subgroup analysis revealed that aged 50–60 year, IV, N2, radiotherapy dose ≥ 60 Gy, without previous surgery, and neoadjuvant therapy have a trend of survival benefit with nimotuzumab. Nimotuzumab showed favorable safety, only 0.2% had nimotuzumab‐related severe adverse events. Our study indicated the nimotuzumab plus chemoradiotherapy provides survival benefits and safety for LA‐HNSCC patients in an IMRT era. [ABSTRACT FROM AUTHOR]

Objective: Endothelial glycocalyx (EG) maintains vascular homeostasis and is destroyed after one‐lung ventilation (OLV)‐induced lung injury. Long noncoding RNAs (lncRNAs) are critically involved in various lung injuries. This study aimed to investigate the role and regulatory mechanism of KCNQ1 overlapping transcript 1 (KCNQ1OT1) in OLV‐induced lung injury and LPS‐induced type II alveolar epithelial cell (AECII) apoptosis. Methods: The rat OLV model was established, and the effects of KCNQ1OT1 on OLV‐induced ALI in vivo were explored. Bax and Caspase‐3 expression in rat lung tissues was measured by immunochemistry (IHC). AECIIs were isolated from rat lungs and treated with LPS or normal saline (control) for in vitro analysis. The expression of KCNQ1OT1, miR‐129‐5p, and HMGB1 was measured by quantitative real‐time PCR (qRT‐PCR) or Western blot (WB). Cell proliferation and apoptosis were examined by 3‐(4,5)‐dimethylthiahiazo (‐z‐y1)‐3,5‐di‐ phenytetrazoliumromide (MTT) and flow cytometry. The downstream targets of KCNQ1OT1 were predicted by bioinformatics, and the binding relationship between KCNQ1OT1 and miR‐129‐3p was verified by dual‐luciferase reporter assays. The potential target of miR‐129‐5p was further explored on the Targetscan website and revealed to target HMGB1. Enzyme‐linked immunosorbent assay (ELISA) or WB was adopted to determine the levels of IL‐1β, TNF‐α, MDA, SOD, heparanase (HPA), matrix metalloproteinase 9 (MMP9), heparan sulfate (HS) and syndecan‐1 (SDC‐1). Results: KCNQ1OT1 and HMGB1 were up‐regulated during OLV‐induced lung injury, and their expression was positively correlated. KCNQ1OT1 knockdown reduced OLV‐induced pulmonary edema and lung epithelial cell apoptosis, increased vascular permeability, reduced IL‐1β, TNF‐α, MDA, and SOD levels and glycocalyx markers by targeting miR‐129‐5p or upregulating HMGB1. Overexpressing KCNQ1OT1 promoted cell apoptosis, reduced cell proliferation, aggravated inflammation and oxidative stress, and up‐regulated HMGB1, HPA and MMP9 in LPS‐treated AECIIs, while the HMGB1 silencing showed the opposite effects. MiR‐129‐5p mimics partially eliminated the KCNQ1OT1‐induced effects, while recombinant HMGB1 restored the effects of miR‐129‐5p overexpression on AECIIs. Additionally, KCNQ1OT1 was demonstrated to promote the activation of the p38 MAPK/Akt/ERK signaling pathways in AECIIs via HMGB1. Conclusion: KCNQ1OT1 knockdown alleviated AECII apoptosis and EG damage during OLV by targeting miR‐129‐5p/HMGB1 to inactivate the p38 MAPK/Akt/ERK signaling. The findings of our study might deepen our understanding of the molecular basis in OLV‐induced lung injury and provide clues for the targeted disease management. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is one of the most common chronic airway diseases in the world. OBJECTIVE: To predict the degree of mixed venous oxygen saturation (SvO2) impairment in patients with COPD by modeling using clinical-CT radiomics data and to provide reference for clinical decision-making. METHODS: A total of 236 patients with COPD diagnosed by CT and clinical data at Xiangyang No. 1 People's Hospital (n = 157) and Xiangyang Central Hospital (n = 79) from June 2018 to September 2021 were retrospectively analyzed. The patients were divided into group A (SvO ⩾ 2 62%, N = 107) and group B (SvO < 2 62%, N = 129). We set up training set and test set at a ratio of 7/3 and time cutoff spot; In training set, Logistic regression was conducted to analyze the differences in general data (e.g. height, weight, systolic blood pressure), laboratory indicators (e.g. arterial oxygen saturation and pulmonary artery systolic pressure), and CT radiomics (radscore generated using chest CT texture parameters from 3D slicer software and LASSO regression) between these two groups. Further the risk factors screened by the above method were used to establish models for predicting the degree of hypoxia in COPD, conduct verification in test set and create a nomogram. RESULTS: Univariate analysis demonstrated that age, smoking history, drinking history, systemic systolic pressure, digestive symptoms, right ventricular diameter (RV), mean systolic pulmonary artery pressure (sPAP), cardiac index (CI), pulmonary vascular resistance (PVR), 6-min walking distance (6MWD), WHO functional classification of pulmonary hypertension (WHOPHFC), the ratio of forced expiratory volume in the first second to the forced vital capacity (FEV1%), and radscore in group B were all significantly different from those in group A (P < 0.05). Multivariate regression demonstrated that age, smoking history, digestive symptoms, 6MWD, and radscore were independent risk factors for SvO2 impairment. The combined model established based on the abovementioned indicators exhibited a good prediction effect [AUC: 0.903; 95%CI (0.858–0.937)], higher than the general clinical model [AUC: 0.760; 95%CI (0.701–0.813), P < 0.05] and laboratory examination-radiomics model [AUC: 0.868; 95%CI (0.818–0.908), P = 0.012]. The newly created nomogram may be helpful for clinical decision-making and benefit COPD patients. CONCLUSION: SvO2 is an important indicator of hypoxia in COPD, and it is highly related to age, 6MWD, and radscore. The combined model is helpful for early identification of SvO2 impairment and adjustment of COPD treatment strategies. [ABSTRACT FROM AUTHOR]

Purpose: To investigate and characterize the performance of a novel orthogonal dual‐layer alpha multileaf collimator (αMLC) mounted on the LinaTech VenusX linac. Methods: We evaluated leaf positioning accuracy and reproducibility using an electronic portal imaging device through the picket fence test. The average, interleaf, intraleaf, and leaf tip transmissions of the single and dual layers were measured using an ionization chamber. Square and rhombus fields were used to evaluate the leaf penumbra of αMLC. To investigate the advantages of the orthogonal dual‐layer multileaf collimator (MLC) in field shaping, right triangular and circular pattern fields were formed using both the dual layers and single layers of the αMLC. Results: The average maximum positioning deviations of the upper and lower αMLC over 1 year were 0.76 ± 0.09 mm and 0.62 ± 0.07 mm, respectively. The average transmissions were 1.87%, 1.83%, and 0.03% for the upper‐, lower‐ and dual‐layer αMLC, respectively. The maximum interleaf transmissions of the lower‐ and dual‐layer were 2.43% and 0.17%, respectively. The leaf tip transmissions were 9.34% and 0.25%, respectively. The penumbra of the square field was 6.2 mm in the X direction and 8.0 mm in the Y direction. The average penumbras of the rhombus fields with side lengths of 5 and 10 cm were 3.6 and 4.9 mm, respectively. For the right triangular and circular fields, the fields shaped by the dual‐layer leaves were much closer to the set field than those shaped by single‐layer leaves. The dose undulation amplitude of the 50% isodose lines and leaf stepping angle change of the dual‐layer leaves were smaller than those of the single‐layer leaves. Conclusions: The αMLC benefits from its orthogonal dual‐layer design. Leaf transmission, dose undulations at the field edge, and MLC field dependence of the leaf stepping angle of the dual‐layer αMLC were remarkably reduced. [ABSTRACT FROM AUTHOR]

This article presents a summary of three common false-bottom occurrences in echosounder imaging based on an analysis of echosounder data. Utilizing the imaging principle of the echosounder, a comprehensive analysis was conducted and an explanation of each situation's causes, imaging characteristics, impacts, and solutions is presented. Additionally, the article includes calculations to determine the precise location of the false bottom, which were subsequently validated through actual data collection. To address the two most impactful false-bottom scenarios in target detection, solutions are proposed from two perspectives. By accurately judging the position and imaging characteristics of these false bottoms, the article concludes with an analysis of the causes of false bottoms and presents corresponding solutions. The article aims to facilitate the rapid identification and elimination of false bottoms, thus mitigating their adverse effects on target detection. [ABSTRACT FROM AUTHOR]

Steel wire rope usually works in harsh environments, making it prone to damage during frequent use. Magnetic flux leakage testing is an important way of non-destructive testing, preventing some major accidents of hoist equipment by identifying the damage to steel wire ropes. Whereas, the harsh environment usually generates noise and results in difficulty in extracting the damage features of the magnetic flux leakage signal, which makes it hard to identify the damage. The fast Walsh-Hadamard transform is widely used in signal processing. The denoising effect depends closely on the transform coefficients. If the transformation coefficients can be adaptively retained, better denoising effects can be achieved. Therefore, we propose the adaptive fast Walsh-Hadamard transform to extract the magnetic flux leakage signal of steel wire rope under noise background. Using the cross-correlation co efficient and the similarity of the greyscale histogram as the indexes, the Fast Walsh-Hadamard transform combines the adaptive particle swarm optimisation to adaptively retain the optimal transformation coefficient and then gets the optimal denoising signal. Meanwhile, compared to wavelet denoising methods, the adaptive fast Walsh-Hadamard transform can effectively improve denoising performance in peak-to-peak reductivity and can be successfully used in steel wire rope damage extraction. [ABSTRACT FROM AUTHOR]