Spatial distribution characteristics and influence factor analysis of landslides——case study of the Hanwang area in Qinba Mountains

The geological hazards of landslides in Hanwang Town, Ziyang County, Ankang City, Shaanxi Province, have emerged. Yet, the current understanding of the spatial distribution characteristics and influencing factors of landslides in this area remains unclear. Combining the results of remote sensing interpretation and field investigation, seven influencing factors, namely, elevation, slope direction, slope gradient, distance from rivers, distance from faults, engineering geologic lithology, and distance from roads, are selected for the study. The distribution characteristics of landslides in each influencing factor and the influence of the resolution of the Digital Elevation Model(DEM) on the results are statistically and analytically analyzed. Furthermore, two highrisk landslides within the study area were subjected to comprehensive analysis, integrating the findings from drilling and other field investigations in order to examine their deformation mechanisms. Based on this analysis,the following conclusions were derived:(1) 34 landslides in the study area, mainly small earth landslides, with a distribution density of 0.42/km~2, threatening 414 people and property of about 55.87 million Yuan.(2)The landslides in the study area easily occur in the <400 m elevation range;the landslides are developed in all slope directions, the gradient is mainly concentrated in the range of 10°–40°, the distribution density of the landslides is higher in the closer distance from the river and the faults(0–200 m), the landslide-prone strata are mainly the softer and weaker metamorphic rocks, and the landslides are mainly around roads.(3) The resolution of the DEM should be selected based on the specific conditions of the study area, the requirements of the investigation, and the scale of the landslide. Opting for an appropriate DEM resolution is advantageous for understanding the patterns of landslides and conducting risk assessments in the region.(4) The Zhengjiabian landslide is a traction Landslide. The landslide body is a binary structure of gravel soil and slate weathering layer, and the damage process can be divided into three stages:(1)damage to the leading edge and stress release,(2)continuous creep and cracking,(3)rainfall infiltration and damage. The predominant slope material in the Brickyard landslide comprises clay, and the landslide is triggered by a combination of the traction effect resulting from the excavation at the slope's base and the nudging effect caused by the stacking load of the brick factory. Additionally, the Brickyard landslide exhibits persistent creep deformation. The study results provide a scientific basis for disaster prevention and mitigation in the Hanwang Township area.

超支化聚醚阻垢剂的制备及性能

反渗透膜广泛应用于水体过滤和分离领域,但是水体中大量存在的微生物与金属离子会极大地降低其过滤和分离效果,加入阻垢剂是解决这一问题的主要途径。超支化聚合物阻垢剂具有优异的阻垢效果,但通常制备过程繁琐、生产能耗大、工业成本高。为此,文中选用2-丙烯酸-2-(二甲氨基)乙酯(DMAEA)和3-环氧-1-丙醇(GL)为单体,经自催化开环聚合和迈克尔加聚反应制备了端羟基超支化聚醚中间体(HBP-OH),并用丁二酸酐(SA)对其羧化成功制备了超支化聚醚阻垢剂(HBP-COOH)。通过核磁共振氢谱和傅里叶变换红外光谱等确定了HBP-OH和HBP-COOH的超支化结构;通过电导率和抗菌实验等对产物的阻垢和抗菌性能进行了研究。结果显示,在阻垢剂用量为30 mg/L、羧化温度70℃、羧化时间4 h、H2SO占GL质量2%时,HBPCOOH对CaCO垢抑制率高达91.2%、对CaSO垢抑制率达83.5%。阻垢剂对金黄色葡萄球菌(MRSA)的抑制率为98.3%。

Drug repurposing screen identifies vidofludimus calcium and pyrazofurin as novel chemical entities for the development of hepatitis E interventions

Hepatitis E virus(HEV)infection can cause severe complications and high mortality,particularly in pregnant women,organ transplant recipients,individuals with pre-existing liver disease and immunosuppressed patients.However,there are still unmet needs for treating chronic HEV infections.Herein,we screened a best-in-class drug repurposing library consisting of 262 drugs/compounds.Upon screening,we identified vidofludimus calcium and pyrazofurin as novel anti-HEV entities.Vidofludimus calcium is the next-generation dihydroorotate dehydrogenase(DHODH)inhibitor in the phase 3 pipeline to treat autoimmune diseases or SARS-CoV-2 infection.Pyrazofurin selectively targets uridine monophosphate synthetase(UMPS).Their anti-HEV effects were further investigated in a range of cell culture models and human liver organoids models with wild type HEV strains and ribavirin treatment failure-associated HEV strains.Encouragingly,both drugs exhibited a sizeable therapeutic window against HEV.For instance,the IC50 value of vidofludimus calcium is 4.6–7.6-fold lower than the current therapeutic doses in patients.Mechanistically,their anti-HEV mode of action depends on the blockage of pyrimidine synthesis.Notably,two drugs robustly inhibited ribavirin treatment failure-associated HEV mutants(Y1320H,G1634R).Their combination with IFN-αresulted in synergistic antiviral activity.In conclusion,we identified vidofludimus calcium and pyrazofurin as potent candidates for the treatment of HEV infections.Based on their antiviral potency,and also the favorable safety profile identified in clinical studies,our study supports the initiation of clinical studies to repurpose these drugs for treating chronic hepatitis E.

Neodymium naphthenate-loaded organic phase stripping using sodium oxalate

Neodymium naphthenate-loaded organic phase stripping using sodium oxalate solution was studied to explore the feasibility of synchronous rare earth-loaded organic phase stripping,rare earth precipitation,and blank organic phase saponification.Experimental results show that loaded organic phase stripping,rare earth precipitation,and blank organic phase saponification can be realized simultaneously.When using 20% excess of sodium oxalate over the stoichiometry with the volume ratio of organic phase to aqueous phase of 1:1 at 25℃ for 40 min,the single stage stripping rate and saponification value are about 40% and 0.29 mol/L,respectively.After 16 stages of countercurrent continuous stripping,the stripping rate of neodymium can reach 99%,the saponification value is 0.42 mol/L,the Nd^(3+) concentration in saponified organic phase is less than 0.0020 mol/L,and the main phase in precipitation isNd_(2)(C2 O_(4))3·10 H_(2) O.Afterwards,this saponified organic phase can be used in the extraction of NdCl_(3) solution,and then the loaded organic phases(neodymium naphthenate) with 0.16 mol/L Nd^(3+) can be retrieved.The morphology,particle size distribution,and composition of theNd_(2)(C2 O_(4))3·10 H_(2) O products are similar to those of the current direct precipitation products.The neodymium oxide prepared by continuous calcination of neodymium oxalate meets the national standard of China(GB/T 5240-2015).These results prove the feasibility of stripping neodymium naphthenate-loaded organic phase by using sodium oxalate solution.Sodium oxalate can serve as a stripping agent,a saponifier,and a precipitator,thereby simplifying rare earth extraction and separation.This study provides theoretical and technical support for the development of a novel method for rare earth extraction and separation.