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The deep shale of the Wufeng–Longmaxi Formation in the southern Sichuan Basin has high gas potential. The development characteristics of lamination could significantly impact reservoir property. Samples were investigated using microscopic observation, element analysis, organic petrology analysis, mineralogy analysis, and pore structure analysis to determine the types of laminae and laminasets, clarify the formation conditions of argillaceous lamina and silty lamina as well as their relationships with the sedimentary environment, and explore the influence of laminae on shale reservoir property. Results indicate that the Wufeng Formation shale exhibits weak development of laminae due to bioturbation, while the Longmaxi Formation shale develops continuous, parallel, and plate-like laminae. Compared with light silty lamina-rich shale, dark argillaceous lamina-rich shale usually develops in an anoxic reduction environment, with higher total organic carbon content, porosity, pore volume, specific surface area, and more developed organic matter pores, which can provide greater space for shale gas adsorption and storage. Shales in the middle section of the Longmaxi Formation are characterized by the development of silty-argillaceous interbedded type laminaset, which have good reservoir performance, making them the primary target for deep shale gas exploration and development. [ABSTRACT FROM AUTHOR]

Objective To analyze the epidemic characteristics of hand foot and mouth disease (HFMD) in Sichuan province from 2017 to 2021 and to provide evidence for prevention and control. Methods A descriptive analysis was conducted by downloading the case-data of HFMD in Sichuan province during 2017 to 2021 from the Chinese National Notifiable Infectious Disease Reporting System. Results A total of 442 079 cases of HFMD were reported from 2017 to 2021, including 627 severe cases and 4 deaths. The average annual incidence rate was 106.17/100 000.Cases in children aged 5 or younger accounted for 90.99%. Boys had higher incidence than girls (1.35:1). The scattered children accounted for 63.34%. Two peaks of incidence were observed other years, except for a few years, with the highest occurring between April to July and the second occurring in November to December. The incidence in Chengdu plain and its surrounding areas were significantly higher than other regions. Other enteroviruses (non-enterovirus 71 and Coxsackie virus A16) were the main pathogen, accounting for 71.45%; Coxsackie virus A16 accounted for 21.20% and enterovirus 71 accounted for 7.35%. Conclusion The incidence of HFMD in Sichuan Province is high from 2017 to 2021. The proportion of severe cases has significantly decreased (χ² = 273.241, P <0.001), and the main pathogen is the other enteroviruses (non-enterovirus 71 and Coxsackie virus A16). [ABSTRACT FROM AUTHOR]