ABSTRACT
Southeastern Tibet features a complex geological environment and a high incidence of earthquakes. Earthquake-induced chain disasters pose a great threat to engineering construction and public safety in this area, and landslides are among the most frequent postearthquake disasters. To investigate the impact of earthquakes on landslides, this study constructed a comprehensive database for landslide susceptibility analysis based on various factors, including elevation, slope, slope direction, distances from roads and rivers, proximity to faults, land use patterns, rainfall patterns, and seismic parameters. By integrating the frequency ratio (FR) model with the analytic hierarchy process (AHP) model, this work delineated landslide susceptibility zones in southeastern Tibet. Subsequently, the susceptibility zoning layer was overlaid with the magnitude sensitivity layer and validated using ROC curve analysis to identify the earthquake magnitudes that exerted the greatest influence on landslides. Finally, by incorporating the distance from earthquake epicentres into our refined model framework, different monitoring levels for landslide susceptibility zoning were established. The AHP results show the relative importance of the landslide-influencing factors in southeastern Tibet can be ranked as follows: elevation, slope direction, distance from road, land use, distance from river, slope, and rainfall. The ROC values of the landslide models with seismic sensitivities of 1, 2 and 3 are 0.876, 0.883 and 0.877, respectively, indicating that earthquakes of magnitude 4 and above have a great influence on landslides in the study area. Through the overlay of the landslide susceptibility zoning map and the vector map of distance from seismic focal points, a correlation with the distance between landslide-prone areas and seismic focal points is identified. Within the extremely high susceptibility area and within 40 km of the focal point, there are 220 landslide points, accounting for approximately 34 % of the total landslides in the study area. Additionally, 133 landslide points are located in the extremely susceptible area and within 40-80 km of the focal point, representing approximately 20 % of the total landslides in the study area. The susceptible areas were assessed based on grades, resulting in the production of 4 maps depicting different levels of monitoring for landslide-prone areas. These maps are valuable tools for implementing landslide disaster prevention measures within the study area.
ABSTRACT
Objective:To analyze the expression level of minichromosome maintenance protein 6 (MCM6) in colon cancer tissues, the correlation between the expression level of MCM6 and the clinicopathological characteristics of colon cancer patients, and the correlation between MCM6 and PCNA expression.Methods:The expression levels of MCM6 in different tumor tissues were analyzed based on the Human Protein Atlas (HPA) database. The expression levels and correlations of MCM6 and PCNA in colon cancer tissues were analyzed based on The Cancer Genome Atlas (TCGA) database and immunohistochemical experiments. The correlation between MCM6 expression level and clinical characteristics of colon cancer patients was analyzed. The correlation between MCM6 and PCNA expression in colon cancer was analyzed based on TCGA database and Gene Expression Profile Interaction Analysis (GEPIA) database.Results:Bioinformatics analysis and immunohistochemical results confirmed that MCM6 was highly expressed in colon cancer tissues, and its expression level was correlated with the tumor stage of patients ( P=0.01). In colon cancer, the expression of MCM6 and PCNA was correlated with statistical significance ( P<0.05). Conclusions:MCM6 is highly expressed in colon cancer tissue and is related to the clinical characteristics of patients, suggesting that MCM6 can be used as a potential marker of colon cancer.
ABSTRACT
It is important to simulate the excitation propagation process of cardiac bio-electricity in the research of ECG forward problem. Traditional methods describe them with wave simulation algorithm such as LFX simulation algorithm and vector propagation algorithm etc, these methods have some problems to certain extent, due to the presence of discreteness of space and time and asymmetry of the myocardium. This paper discussed the simulation algorithm in 2-dimension space under the circumstance of layered and non-layered structure of myocardium. By calculating the theoretic values of simulating time based on Huygen's principle, we found that there were errors in LFX algorithm and no errors in vector propagation algorithm under the circumstance of non-layered structure of the myocardium, no mater what myocardium is isotropic or anisotropic. However, there exist errors from both algorithms when the myocardium has the layered structure. An improved algorithm is proposed and the simulations have been performed to examine the efficacy of the new algorithm, and the errors are reduced obviously. By increasing the number of myocardial blocks in the model, we also analyzed its influence on the error of simulation algorithm.