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Complex underground conditions make it challenging to conduct extensive coring, and it is difficult for laboratories to carry out a large number of rock mechanics experiments due to the limited number of cores. Rock-like specimens are commonly used in the laboratory to replace coal-rock specimens. In this paper, rock-like specimens with different proportions are produced to study the mechanical properties, failure characteristics, and acoustic emission laws of rock-like specimens under uniaxial compression. The results show that when the rock-like specimen does not contain gypsum, the stress of the specimen decreases rapidly after reaching the peak stress, which is similar to the mechanical properties of hard brittle rock. When the rock-like specimen contains gypsum, the stress of the specimen decreases slowly after reaching the compressive limit, and the failure of the specimen is gentle, which is similar to the mechanical properties of soft rock. When the specimen lacks gypsum, the strength of the rock-like specimen is larger, and the strength of the specimen is positively correlated with the proportion of cement. When the specimen contains gypsum, the strength of the rock-like specimen decreases sharply, and the strength of the rock-like specimen is negatively correlated with the proportion of gypsum. The maximum acoustic emission ringing count increases with higher cement content but decreases with increased gypsum content. The cumulative count change of acoustic emissions approximately underwent four stages, aligning well with the four stages of uniaxial compression failure observed in typical rock. The research results have important reference value for the selection of rock-like materials to replace the original rock materials for laboratory research. [ABSTRACT FROM AUTHOR]

Background: The Prognostic Nutritional Index (PNI) has become an important predictive tool for assessing patients' nutritional status and immune competence. It is widely used in prognostic evaluations for various cancer patients. However, the prognostic relevance of the Prognostic Nutritional Index (PNI) in gastric or gastro-esophageal junction cancer patients (GC/GEJC) undergoing immune checkpoint inhibitors (ICIs) treatment remains unclear. This meta-analysis aimed to determine the prognostic impact of PNI in this specific patient cohort., Methods: We conducted a thorough literature search, covering prominent databases such as PubMed, Embase, Web of Science, SpringerLink, and the Cochrane Library. The search spanned from the inception of these databases up to December 5, 2023. Employing the 95% confidence interval and Hazard Ratio (HR), the study systematically evaluated the relationship between PNI and key prognostic indicators, including the objective remission rate (ORR), disease control rate (DCR), overall survival (OS) and progression-free survival (PFS) in GC/GEJC patients undergoing ICI treatment., Results: Eight studies comprising 813 eligible patients were selected. With 7 studies consistently demonstrating superior Overall Survival (OS) in the high-Prognostic Nutritional Index (PNI) group compared to their low-PNI counterparts (HR 0.58, 95% CI: 0.47-0.71, P<0.001). Furthermore, the results derived from 6 studies pointed out that the significant correlation between he low-PNI and poorer progression-free survival (PFS) (HR 0.58, 95% CI: 0.47-0.71, P<0.001). Subgroup analyses were performed to validate the robustness of the results. In addition, we conducted a meta-analysis of three studies examining the correlation between PNI and objective response rate/disease control rate (ORR/DCR) and found that the ORR/DCR was significantly superior in the high PNI group (ORR: RR: 1.24, P=0.002; DCR: RR: 1.43, P=0.008)., Conclusion: This meta-analysis indicates that the low-PNI in GC/GEJC patients undergoing ICI treatment is significantly linked to worse OS and PFS. Therefore, PNI can serve as a prognostic indicator of post-treatment outcomes in patients with GC receiving ICIs. Further prospective studies are required to assess the reliability of these findings., Systematic Review Registration: https://inplasy.com/, identifier INPLASY202450133., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hou, Song, Hao, Li, Zhang and Zhu.)