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As one of the core issues of roof cutting pressure relief gob-side entry retaining technology, roof cutting parameters have a great influence on the stability of surrounding rock.Taking the 1226 working face of Shuguang Mine as the engineering background, the reference values of cutting top height and cutting top Angle are 7.1~9.5 m and 11.4° respectively through theoretical analysis.Through numerical simulation, the roof collapse form, roof subsidence and stress distribution of solid coal side are analyzed when the roof cutting height is 4 m, 7 m, 10 m, 13 m and the roof cutting Angle is 0°, 10°, 15°, 20° and 30° respectively from two angles of roof cutting effect and surrounding rock deformation.The results show that the optimal cutting top parameters are the cutting top height 10 m and the cutting top Angle 15°.The optimum hole spacing, blasting method and charge quantity are determined by field blasting test.The surrounding rock deformation of the rear roadway of the working face was monitored after the roadway retaining.The deformation of the surrounding rock of the roadway was small and the effect of the roadway retaining was good.

Background and purpose: Serine/arginine-rich splicing factor 1 (SRSF1) is closely related to the development of tumor. Esophageal carcinoma is the common malignant tumor of digestive system. However, the role of SRSF1 in esophageal carcinoma is rarely reported. This study aimed to detect the expression of SRSF1 in esophageal squamous cell carcinoma (ESCC) and its effects on the proliferation, invasion and migration of ESCC cells, and to explore its mechanism. Methods: Forty pairs of ESCC tissues and paracancerous tissues resected at the Fourth Hospital of Hebei Medical University from January 2020 to December 2021 were collected for this study. The expression of SRSF1 in ESCC was detected by immunohistochemistry. The mRNA expression and protein level of SRSF1 in ESCC cells were detected by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) and Western blot, respectively. Eca9706 cell with high expression of SRSF1 was selected. The mRNA expression of SRSF1 was reduced by small interfering RNA (siRNA). The proliferation, migration and invasion of Eca9706 cells were detected by cell counting kit-8 (CCK-8), transwell and Matrigel matrix gel assays, respectively. Database was used to analyze the expression of vascular endothelial growth factor A (VEGFA) in ESCC tissues, and the correlation between expressions of SRSF1 and VEGFA was also analyzed. RTFQ-PCR was used to detect the expression levels of VEGFA Iso8a and Iso8b isoform in Eca9706 cells, and the change in VEGFA Iso8a and Iso8b isoform expressions was also detected after knocking down SRSF1. Results: The expression of SRSF1 was significantly higher in ESCC tissues than in normal esophageal tissues (P

Objective To investigate the expression of LncRNA DLEU1 in ESCC tissues, and its effect on the proliferation and migration of ESCC cells. Methods We collected 58 cases of ESCC tissues and corresponding para-cancerous tissues. RT-qPCR was used to detect the relative expression levels of DLEU1 in ESCC tissues and cells. Log-rank test was used to analyze the relation between the expression of DLEU1 and clinicopathological features. Kaplan-Meier analysis was used to investigate the correlation between the expression of DLEU1 and the survival of ESCC patients. Multivariate Cox regression model was used to evaluate the effect of DLEU1 on the prognosis of ESCC patients. Effects of DLEU1 on the proliferation and migration of Eca9706 cells were evaluated by CCK-8 and wound healing assays, respectively. Results DLEU1 was highly expressed in ESCC tissues (P < 0.01) and significantly correlated with tumor size, TNM stage and lymph node metastasis (all P < 0.05). High expression of DLEU1 was negatively correlated with poor prognosis of ESCC patients (P < 0.01), and DLEU1 was also an independent prognostic risk factor (P < 0.05). Moreover, knockdown of DLEU1 significantly inhibited the proliferation and migration of Eca9706 cells, compared with the control group (P < 0.01). Conclusion DLEU1 is highly expressed in ESCC tissues. The expression of DLEU1 is an independent risk factor for the prognosis of ESCC patients and promotes ESCC cell proliferation and migration.

Intestinal microbiota is symbiotically associated with host health, learning about the characteristics of microbiota and the factors that modulate it could assist in developing strategies to promote human health and prevent diseases. Polysaccharides from Lycium barbarum (LBPs) are found beneficial for enhancing the activity of gut microbiota, as a potential prebiotic, which not only participates in improving body immunity, obesity, hyperlipidemia and systemic inflammation induced by oxidative stress, but also plays a magnificent role in regulating intestinal microenvironment and improving host health and target intestinal effects via its biological activities, as well as gut microbiota and metabolites. To highlight the internal relationship between intestinal microbiota and LBPs, this review focuses on the latest advances in LBPs on the intestinal microbiota, metabolites, immune regulation, intestinal barrier protection, microbiota-gut-brain axis and host health. Moreover, the preparation, structure, bioactivity and modification of LBPs were also discussed. This review may offer new perspective on LBPs improving health of gut and host via intestinal microbiota, and provide useful guidelines for the application of LBPs in the food industry. [ABSTRACT FROM AUTHOR]

The DC voltage ratio standard device is an important tool for calibrating DC voltage transformers. At the 1100 kV voltage level, an increase in electric field intensity will increase the local heat generated inside the device, affecting the accuracy of its measurement. Using a suitable grading ring can even out the electric field intensity and reduce the maximum field strength to improve its measurement accuracy. This article mainly optimizes the design of the grading-ring structure of the 1100 kV DC voltage ratio standard device. First, a finite-element model of the 1100 kV DC voltage ratio standard device was built based on ANSYS; the electric field distribution around the voltage divider was calculated and analyzed, and a data set was constructed based on the calculation results. Secondly, for the optimization of electric field strength, this article presents the design of the nation standard device neural network, which learns the relationship between the structural parameters of the toroidal core and the field strength under the PyTorch 1.8 deep learning framework. Due to the strong convergence performance, few parameters, and ease of implementation of the grey wolf optimization algorithm, this study selected this algorithm to optimize the structural parameters of the grading ring. Finally, simulation examples are established in Python for validation. The experimental results indicate that the maximum field strength of the grading ring decreased from 12,161.1348 V/cm to 10,009.2881 V/cm, a reduction of 17.69%. The optimized structural parameters of the grading ring effectively reduced the electric field intensity around the 1100 kV DC voltage proportional standard device, providing a reliable and practical design approach for the selection of the DC voltage ratio standard device. [ABSTRACT FROM AUTHOR]