In-situ observations of damage-fracture evolution in surrounding rock upon unloading in 2400-m-deep tunnels

The damage-fracture evolution of deep rock mass has obvious particularity, which is revealed in 2400-m-deep tunnels by field tests. The evolution of the excavation damaged zone depth is consistent with that of the fractured zone depth. The ratio of the excavation damaged zone depth to the excavation fractured zone depth is greater than 2.0 in a rock mass with both high strength and good integrity, but less than 1.5 in a rock mass with lower strength or poor integrity. Zonal disintegration in a rock mass with high strength and fair integrity is more likely to occur when it contains more than two groups of primary fractures in damaged zones. Fractures develop outward in zonal disintegration but are totally different from the single-zone fracture, in which the fractures develop inward, and it is the starting position of the fractured zone when the excavation surface of the middle pilot is 7–9 m close to the pre-set borehole and it stops after the excavation surface of the baseplate is 11–14 m away. The most intense evolution occurs around 2–4 m from the pre-set borehole in the sidewall expansion stage. The research results provide a reference for the monitoring scheme and support design of CJPL-III in its future construction

SEIARN: Intelligent Early Warning Model of Epidemic Spread Based on LSTM Trajectory Prediction

A SEIARN compartment model with the asymptomatic infection and secondary infection is proposed to predict the trend of COVID-19 more accurately. The model is extended according to the propagation characteristics of the novel coronavirus, the concepts of the asymptomatic infected compartment and secondary infection are introduced, and the contact rate parameters of the improved model are updated in real time by using the LSTM trajectory, in order to make accurate predictions. This SEIARN model first builds on the traditional SEIR compartment model, taking into account the asymptomatic infection compartment and secondary infection. Secondly, it considers the disorder of the trajectory and uses the improved LSTM model to predict the future trajectory of the current patients and cross-track with the susceptible patients to obtain the contact rate. Then, we conduct real-time updating of exposure rates in the SEIARN model and simulation of epidemic trends in Tianjin, Xi’an, and Shijiazhuang. Finally, the comparison experiments show that the SEIARN model performs better in prediction accuracy, MSE, and RMSE

Patient-specific iPSC-derived cardiomyocytes reveal aberrant activation of Wnt/β-catenin signaling in SCN5A-related Brugada syndrome

Abstract Background Mutations in the cardiac sodium channel gene SCN5A cause Brugada syndrome (BrS), an arrhythmic disorder that is a leading cause of sudden death and lacks effective treatment. An association between SCN5A and Wnt/β-catenin signaling has been recently established. However, the role of Wnt/β-catenin signaling in BrS and underlying mechanisms remains unknown. Methods Three healthy control subjects and one BrS patient carrying a novel frameshift mutation (T1788fs) in the SCN5A gene were recruited in this study. Control and BrS patient-specific induced pluripotent stem cells (iPSCs) were generated from skin fibroblasts using nonintegrated Sendai virus. All iPSCs were differentiated into cardiomyocytes using monolayer-based differentiation protocol. Action potentials and sodium currents were recorded from control and BrS iPSC-derived cardiomyocytes (iPSC-CMs) by single-cell patch clamp. Results BrS iPSC-CMs exhibited increased burden of arrhythmias and abnormal action potential profile featured by slower depolarization, decreased action potential amplitude, and increased beating interval variation. Moreover, BrS iPSC-CMs showed cardiac sodium channel (Nav1.5) loss-of-function as compared to control iPSC-CMs. Interestingly, the electrophysiological abnormalities and Nav1.5 loss-of-function observed in BrS iPSC-CMs were accompanied by aberrant activation of Wnt/β-catenin signaling. Notably, inhibition of Wnt/β-catenin significantly rescued Nav1.5 defects and arrhythmic phenotype in BrS iPSC-CMs. Mechanistically, SCN5A-encoded Nav1.5 interacts with β-catenin, and reduced expression of Nav1.5 leads to re-localization of β-catenin in BrS iPSC-CMs, which aberrantly activates Wnt/β-catenin signaling to suppress SCN5A transcription. Conclusions Our findings suggest that aberrant activation of Wnt/β-catenin signaling contributes to the pathogenesis of SCN5A-related BrS and point to Wnt/β-catenin as a potential therapeutic target

Fiber-Integrated All-Optical Signal Processing Device for Storage and Computing

All-optical signal processing is crucial for high-speed optical fiber communication networks. However, current methods utilizing nonlinear media have limitations such as complex preparation, weak nonlinear effects, and requiring additional energy during operation. To overcome these issues, we demonstrate a fiber-integrated all-optical signal processing device based on Ge2Sb2Te5 (GST). This device can perform a storage function and matrix-vector multiplication (MVM) function. Our device is composed of a single-mode fiber and a step-index multimode fiber with a GST layer deposited on the end face of the multimode fiber. By constructing a special Bessel-like light field, we can achieve the 19-level of storage with low switching energy (90 nJ), large contrast ratio (47%), and fast switching time of a single pulse (200 ns). We also demonstrate MVM operation by connecting two memory units in parallel. These features make our all-optical signal processing unit ideal for data storage/processing applications such as photonic neural networks and neuromorphic computing architectures