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Numerous Quaternary deposits are existed in the mountainous areas of Southwest China, especially in the transition zone between the Qinghai-Tibet Plateau and the Sichuan Basin, where strong tectonic movements and frequent climatic changes increase the potential landslides. The possible deformation and failure process of potential landslides and their impacts on the surrounding environment are important research topics. Field investigation and monitoring indicate that the Qingliu landslide in Xiameng town, Li County, Sichuan Province, China has been continuously deforming since August 2020. The deformation zone has a maximum deformation depth of approximately 18.9 m, a total area of 54,628 m2, and a volume of 34.0×104 m3, which seriously threatens infrastructure projects and dwellings. As a result, understanding the Qingliu landslide evolution process, assessing the hazard risk, and planning disaster prevention measures are of great significance for reducing disaster loss. In this study, the mass movement process and hazard risk of the Qingliu landslide are evaluated, and the effects of different prevention measures are compared and discussed. By using the depth-integrated method, the mass movement of the Qingliu landslide is analyzed. The numerical simulation results indicate that the maximum velocity of the Qingliu landslide is approximately 37.5 m/s, and the duration of the landslide is approximately 90s. The simulated landslide can eventually form a deposited mass with a maximum deposit thickness of 19.4 m and an area of approximately 60,168.3 m2, thereby blocking the river and burying dwellings. Furthermore, a risk assessment of the Qingliu landslide under different forms of protection measures is also produced and discussed by considering the hazard level and economic vulnerability level of the affected area. Setting three layers of anti-slide piles on the deformation zone to reduce the hazard risk of the Qingliu landslide is a better choice. Our results may be useful for planning prevention measures and improving disaster emergency response systems. [ABSTRACT FROM AUTHOR]

The intrusion of debris avalanches into reservoirs frequently occurs in mountainous regions and is a complex solid-fluid interaction. A coupled discrete element method (DEM) and smooth particle hydrodynamics (SPH) method is developed to forecast the entire process of disaster chains including landslide motion, wave generation, and wave propagation on Kaiding slopes at the Houziyan Reservoir, Sichuan Province, China. The sliding masses are treated as granular assemblies with collisions instead of rigid solid. The simulation results indicate that the maximum velocity of debris avalanches when swarming into the water surface is beyond 30 m/s, and the maximum wave elevation on the watercourse and the maximum run-up wave elevation generated by landslides reach 1867.4 m and 1883.0 m, respectively, and the minimum wave trough is 1822.1 m occurring near opposite bank of landslide. Furthermore, the range of landslide-generated waves is estimated to be approximately a propagation distance of 800.0 m along the axis of the river. The coupled DEM-SPH simulation method provides important inspiration for hazard prevention on reservoir landslides. [ABSTRACT FROM AUTHOR]

There is an increased demand for the accurate prediction of fog events in the Sichuan Basin(SCB) using numerical methods. A dense fog event that occurred over the SCB on 22 December 2016 was investigated. The results show that this dense fog event was influenced by the southwest of a low pressure with a weak horizontal pressure gradient and high relative humidity. This fog event showed typical diurnal variations. The fog began to form at 1800 UTC on 21 December 2016(0200 local standard time on 22 December 2016) and dissipated at 0600 UTC on 22 December 2016(1400 local standard time on 22 December 2016). The Weather Research and Forecasting model was able to partially reproduce the main features of this fog event and the diurnal variation in the local mountain to basin winds. The simulated horizontal visibility and liquid water content were used to characterize the fog. The mountain to basin winds had an important role in the diurnal variation of the fog event. The positive feedback mechanism between the fog and mountain to basin winds was good for the formation and maintain of the fog during the night. During the day, the mountain to basin wind displayed a transition from downslope flows to upslope flows. Water vapor evaporated easily from the warm, strong upslope winds, which resulted in the dissipation of fog during the day. The topography surrounding the SCB favored the lifting and condensation of air parcels in the lower troposphere as a result of the low height of the lifting condensation level. [ABSTRACT FROM AUTHOR]

Background: Infection with high-risk human papillomavirus is an important factor associated with cervical cancer, and the distribution of HPV types varies greatly worldwide. Determination of typespecific HPV prevalence constitutes an important step towards the development of vaccines for the prevention of cervical cancer. Methods: The human papillomavirus (HPV) genotypes in 190 cervical cancer specimens taken from the Sichuan province, the most populous province of Southwest China, were detected by a combination of MY09/11 consensus primers PCR (MY09/11 PCR), type-specific primers one-step PCR (One-step TS PCR) and E6/E7 gene type-specific primers nested PCR (Nested TS PCR). The prevalence and distribution of HPV in patients with cervical cancer, especially for HPV types 16, 18, 52, 58 and 59, suspected to be most common in certain parts of China, was investigated. Results: The HPV infection rates detected by MY09/11 PCR, One-step TS PCR and Nested TS PCR were 159 (83.7%), 145 (76.3%) and 172 (90.5%), respectively. The overall HPV prevalence was 93.2% (177/190). The positive specimens for HPV16, 18, 52, 58 and 59 detected by One-step TSPCR were 111 (58.4%), 14 (7.4%), 6 (3.2%), 13 (6.8%) and 4 (2.1%), respectively. By Nested TSPCR analysis, the detection rates of HPV16, 52, 58 and 59 were increased to 140 (73.7%), 30 (15.8%), 37 (19.5%) and 25 (13.2%), while only 4 (2.1%) additional specimens were found to be infected with HPV18. Conclusion: Our data demonstrate that, besides HPV 16, which was found to be the most prevalent type, HPV types 58, 52 and 59 are more prevalent than HPV18 in women with cervical cancer in the Sichuan area of China. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Infection with high-risk human papillomavirus (hr-HPV) is an important factor associated with cervical cancer. The genetic mutation of HPV16 E6 and integration of HPV16 DNA in the cervical carcinoma tissues are considered important genetic changes in cervical lesion progression. But the studies of hr-HPV epidemiology are relatively less in the area of Sichuan, China. Therefore, we investigated the prevalence of 9 high-risk subtypes and analyzed the genetic mutation characteristic of HPV16 E6 and physical state of HPV16 DNA. Methods: The fragments of L1 and E6 genes were amplified by PCR or nested PCR and then directly sequenced. Further, the multiplex PCR for HPV16 E2 and E6 genes was performed for detection of integration. Results: HPV16, 58 and 18 were prominent, accounting for 78.6%, 20.0% and 9.7%, respectively in 145 isolates. E6 variants revealed that the European (EP) prototype and East Asia (EA) strain were 26 (23.0%) and 34 (30.1%), respectively. Furthermore, there were 14 base substitutions in E6 regions of the study group, of which 12 resulted in amino acid changes and the rest was silent mutation. Significantly, the 240G substitution exactly located the P53 degradation site. Overall, 8 of 114 (7.0%) isolates only contained integrated HPV16 DNA, 43 (37.7%) only contained episomal DNA and 63 (55.3%) contained both integrated and episomal DNA. The proportion of disruption of an intact E2 gene in the patients with cervical cancer is much lower than that in the previous studies. Conclusions: HPV16, 58 and 18 were mainly prevailing subtypes in patients with cervical cancer from Sichuan areas, China and EP/EA strains were predominant in these areas. Some mutations of E6 gene, which lead to the amino acid changes, may be more potentially carcinogenic and the proportion of disruption of an intact E2 gene is much lower. [Copyright &y& Elsevier]