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Objective: To validate the application value of Kyoto gastritis score in diagnosing Helicobacter pylori (Hp) infection status under gastroscopy in Chinses population, and to construct a modified prediction model to improve the diagnostic value of Hp infection. Methods: A total of 749 cases who underwent gastroscopy at the Digestive Endoscopy Center of the Ninth People's Hospital (North), Shanghai Jiao Tong University School of Medicine, from January 1, 2021 to June 1, 2023 were retrospectively collected. Patients were divided into Hp-positive group and Hp-negative group based on histopathological biopsy or 13C breath test results. The endoscopic mucosal manifestations were recorded according to the Kyoto classification of gastritis, including atrophy, intestinal metaplasia, fold enlargement, diffuse redness, nodularity, RAC, red streak, and other 18 manifestations to verify the diagnostic value of Kyoto gastritis score for Hp infection. The mucosal manifestations with significant differences in univariate analysis were included in binary Logistic regression, and a modified prediction model was constructed according to the regression coefficients. ROC analysis was used to analyze the diagnostic value of Kyoto gastritis score and the modified prediction model for Hp infection. Results: The Hp infection rate was 54.47%. Intestinal metaplasia, fold enlargement, nodularity, diffuse redness, spotty redness, and sticky mucus were independent predictors of Hp infection. RAC, red streak, white and flat elevated lesion were independent predictors of Hp non-infection. The area under the curve was 0.861 (95%CI was 0.835~0.887), the accuracy was 75.2%, and the sensitivity and specificity were 88.5% and 65.1%. Mucosal manifestations such as spotty redness, sticky mucus, and RAC were incorporated into the modified prediction model. The results showed that the specificity (85.9%), positive predictive value (88.2%), negative predictive value (85.4%) and AUC [0.929 (95%CI was 0.910-0.947)] of the modified prediction model for Hp infection were higher than those of Kyoto gastritis score [65.1%, 75.2%, 82.5% and 0.861 (95%CI was 0.835-0.887), respectively]. Conclusions: Kyoto gastritis score has a certain application value for Hp in the Chinese population, and the modified prediction model has a higher diagnostic value for Hp infection.

In order to realize the safety, high efficiency and high recovery rate mining of 9-13 m thickness hard coal seam in Jinjitan Coal Mine, the top coal recovery rate and coal wall stability of different cutting heights are analyzed by theoretical analysis and numerical simulation. Based on the corresponding relationship between top coal recovery rate, coal wall stability and cutting height, a super large mining height and small mining and drawing ratio technology which based on mining and supplemented by releasing is proposed. The ZFY21000/35.5/70D two pillar shield hydraulic support with super large mining height is developed. Based on the optimization design of anti impact column and high-efficiency caving mechanism, the problems of easy impact of super high mining height fully mechanized top coal caving face, easy rib spalling of coal wall and easy arching of hard coal are solved. Fully mechanized top coal caving mining with super high mining height and small mining and caving ratio is an effective way to improve recovery rate and realize high yield and high efficiency of extra thick hard coal.

To explore the evolution law of overburden strata during the mining of huge thick coal seams, an experimental study on the distribution characteristics of the overburden three zones with large mining height was carried out. Based on the geological conditions and mining methods of the huge thick coal seam, a two-dimensional physical similarity simulation experiment under the condition of huge thick coal seam was carried out. The results showed that the height of the overburden strata of the huge thick coal seam in Liuhuanggou（９－１５） 06 working face was 60 m. The horizontal fracture density of the overburden strata in the gob was distributed as a parabola as the propulsion distance increased. Affected by the distribution of strata in the “horizontal three zones”, Delamination of goaf was characterized by “high on both sides and low in the middle”. By calculating physical quantities such as mining overburden subsidence, fissure density, and layer separation and other physical quantities, the formula for determining the height of overburden “three zones” under huge thick coal seams was derived.