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First-principles calculations and thermodynamic theory of mixing entropy and enthalpy are employed to study the phase stability, mechanical properties, and melting points of 15 existing and hypothetical quaternary high-entropy metal diborides (HEMB 2 s) composed of boron and six group IVB and VB refractory transition metals. A phase diagram in terms of a structural parameter, δ (the lattice size difference), and two thermodynamic parameters, Δ H m i x (the mixing enthalpy) and Ω (the ratio of the entropy and enthalpy terms) is constructed. The phase diagram shows that all the 15 metal diborides satisfy the established Ω - δ criterion (i.e. Ω > --> 1 and δ < 6.6 %), suggesting that they can be formed as single-phase HEMB 2 s. While five of these equiatomic four-metal diborides were experimentally synthesized already, the remaining ten single-phase HEMB 2 s are predicted by this work. Each of the 15 quaternary HEMB 2 s is found to have high Vickers hardness and high fracture toughness, together with an ultrahigh melting point. [ABSTRACT FROM AUTHOR]

Objective To analyze the mortality trend of esophageal cancer in China from 1990 to 2019, and to provide evidence for formulating and adjusting the prevention and treatment strategy of esophageal cancer. Methods Joinpoint regression model was used to analyze the trend of esophageal cancer mortality. Age - period - cohort ( APC) model was used to estimate the age, period, and cohort effects of esophageal cancer mortality risk. Results From 1990 to 2019, the standardized mortality rate of esophageal cancer in China, women and men showed a downward trend, with an average annual change percentage of - 1. 825%, -3. 092% and - 1. 185%, respectively. APC model showed that the mortality risk of esophageal cancer in females 90 - 94 years old and males 85 - 89 years old was 159 times and 286 times higher than that in 20 - 24 years old. In terms of period effect, the death risk of esophageal cancer in women from 2000 to 2004 was 1. 59 times that in 2010-2014, and that in men from 2015 to 2019 was 1. 57 times that in 1990-1994; In terms of cohort effect, the mortality risk of esophageal cancer in women bom in 1905-1909 and men bom in 1900-1904 was 18. 49 times and 18. 73 times higher than that in 1995-1999, respectively. Conclusion The standardized mortality of esophageal cancer in China is decreasing, and the standardized mortality of esophageal cancer in male is significantly higher than that in female. The risk of death from esophageal cancer increased with age, and the later the residents were born, the lower the risk of death. In the future, we should focus on male and elderly residents, give priority to prevention, combine prevention and treatment, try our best to control the risk factors of esophageal cancer, strengthen publicity and education, advocate healthy lifestyle, and effectively maintain residents' health. [ABSTRACT FROM AUTHOR]

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By combining first-principles density-functional calculations and thermodynamics, we investigated the thermodynamic stability and mechanical properties of 15 quaternary high-entropy metal disilicides composed of silicon and four of the six refractory transition metals Ti, Zr, Hf, V, Nb, and Ta. We constructed a three-dimensional diagram specified by two thermodynamic parameters (the mixing enthalpy and the ratio of the entropy term in the Gibbs free energy to enthalpy) and a structural parameter (the lattice size difference). The obtained diagram allows us to predict that, except for TiZrHfVSi 8 , the formation of all other fourteen single-phase metal disilicides is thermodynamically favorable. Our calculations show that, for the formation of each of the 14 metal disilicides, the driving force suppresses the resistance at temperatures well below the melting point, suggesting that it is feasible to synthesize these high-entropy materials. One of these (TiHfNbTaSi 8 ) has already been experimentally realized. Furthermore, the values of the mechanical parameters and melting points of the predicted fourteen quaternary high-entropy metal disilicides are all greater than the corresponding average values of the four single-metal disilicides., (© 2023 IOP Publishing Ltd.)

To understand the role of denitrifying microbes during vegetation recovery in karst regions, we determined the basic physicochemical properties and abundance of denitrifying microbial functional genes ( nirS , nirK , fungal nirK , p 450 nor , and nosZ ) of 13 collected soil samples under three land use types (cropland, grassland, and plantation) in Northwest Guangxi, and investigated the changes in the abundance of denitrifying microbial functional genes and their driving factors. Results showed that soil pH, soil organic carbon, total nitrogen (TN), and exchangeable calcium (Ca exe ) in plantation soil were significantly higher than those in cropland and grassland. The abundance of nirS , nirK , p 450 nor , and nosZ in plantation soil were significantly higher than those in cropland and grassland. Soil pH, TN, and Ca exe were positively correlated with the abundance of denitrifying functional genes nirS , nirK , and p 450 nor . Results of redundancy analysis showed that soil Ca exe , pH and TN were the primary factors influencing the abundance of denitrifying functional genes, which accounted for 34.1%, 20.1%, and 16.1% of the total variation, respectively. Such a result suggested that Ca exe was the main driver of changes in denitrifying functional genes under different land use types. Overall, vegetation restoration (plantation) could effectively increase soil denitrifying microbe genes abundance in the karst region of Northwest Guangxi, and consequently influence soil nitrogen cycling.

Sugarcane is the most important sugar crop. Sugarcane smut is one of the major diseases, which could reduce sugarcane yield and quality and seriously threaten the sustainable and healthy development of sugar industry. Microbial control of sugarcane smut is a rapidly emerging green biocontrol technology, with advantage to increase environmental compatibility and soil fertility. In this review, we briefly described the characteristics of Sporisorium scitamineum which causes sugarcane smut, synthesized the the mechanisms underlying the infection of sugarcane by S. scitamineum , and presented the research status of microbial controls of sugarcane smut via the application of bio-organic fertilizers and biopesticides. We then reviewed the mechanisms underlying the suppression of sugarcane smut by microorganisms through competition with pathogens for nutrients and ecological niches, secreting antagonistic substances, and improving plant resistance. It is notable that there are still some problems in the application of microbial control technologies, including poor colonization ability and unstable biocontrol efficiency. Finally, the major directions of future research on the biocontrol of sugarcane smut were proposed from the perspective of improving the biocontrol efficiency. This review would benefit the microbial control of sugarcane smut and the healthy development of sugar industry.