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In order to tackle the environmental problems induced by Portland cement production and industrial solid wastes landfilling, this study aims to develop novel ternary cementless fly ash-based geopolymer by recycling red mud and blast furnace slag industrial solid wastes. The fresh-state properties, mechanical strength, water permeability, phase assemblage and microstructure were systematically investigated to evaluate the performance variation and reveal the hydration mechanism for geopolymers with different mixing proportions. The results showed that a higher slag content or a lower red mud content could result in the higher fluidity and shorter setting time for fresh mixture. The existence of slag promoted the transformation of N-A-S-H to C-A-S-H gel, which contributed to higher compressive strength and better resistance to water penetration. However, an excessive incorporation of 30% red mud may impede the generation of N-A-S-H gel and form more flocculent-like loose hydrates, thus to mildly degrade the mechanical strength and anti-permeability. The synergetic utilization of red much and blast furnace slag in fly ash-based geopolymer led to much less CO 2 emission compared with the condition that red much or slag was singly added, which demonstrated prominent environmental advantages for such kind of ternary cementless geopolymer with equivalent mechanical strength. [Display omitted] • A series of novel cementless geopolymers with ternary solid wastes were designed with low CO 2 emission. • Synergetic utilization of red mud and slag endowed fly ash-based geopolymer with adaptive fresh properties. • The influential mechanisms of red mud and slag on strength and permeability of geopolymer were clarified. • The hydration products and microstructure of geopolymer with red mud and slag were revealed. [ABSTRACT FROM AUTHOR]

The spatial heterogeneity of landslide influencing factors is the main reason for the poor generalizability of the susceptibility evaluation model. This study aimed to construct a comprehensive explanatory framework for landslide susceptibility evaluation models based on the SHAP (SHapley Additive explanation)-XGBoost (eXtreme Gradient Boosting) algorithm, analyze the regional characteristics and spatial heterogeneity of landslide influencing factors, and discuss the heterogeneity of the generalizability of the models under different landscapes. Firstly, we selected different regions in typical mountainous hilly region and constructed a geospatial database containing 12 landslide influencing factors such as elevation, annual average rainfall, slope, lithology, and NDVI through field surveys, satellite images, and a literature review. Subsequently, the landslide susceptibility evaluation model was constructed based on the XGBoost algorithm and spatial database, and the prediction results of the landslide susceptibility evaluation model were explained based on regional topography, geology, and hydrology using the SHAP algorithm. Finally, the model was generalized and applied to regions with both similar and very different topography, geology, meteorology, and vegetation, to explore the spatial heterogeneity of the generalizability of the model. The following conclusions were drawn: the spatial distribution of landslides is heterogeneous and complex, and the contribution of each influencing factor on the occurrence of landslides has obvious regional characteristics and spatial heterogeneity. The generalizability of the landslide susceptibility evaluation model is spatially heterogeneous and has better generalizability to regions with similar regional characteristics. Further explanation of the XGBoost landslide susceptibility evaluation model using the SHAP method allows quantitative analysis of the differences in how much various factors contribute to disasters due to spatial heterogeneity, from the perspective of global and local evaluation units. In summary, the integrated explanatory framework based on the SHAP-XGBoost model can quantify the contribution of influencing factors on landslide occurrence at both global and local levels, which is conducive to the construction and improvement of the influencing factor system of landslide susceptibility in different regions. It can also provide a reference for predicting potential landslide hazard-prone areas and for Explainable Artificial Intelligence (XAI) research. • Application of machine learning algorithm (XGBoost) and explainable algorithm (SHAP). • Landslide susceptibility mapping in several study areas with significant differences in regional characteristics. • Reveal the spatial heterogeneity of landslide drivers. • The investigation of the "reproducibility" of the models. [ABSTRACT FROM AUTHOR]

The responses of soil moisture to rainfall are of great significance for watershed hydrological modeling. However, few studies have been done to investigate these responds on hillslope in a typical semi-arid grassland region. This study used high temporal resolution soil moisture data to explore the soil moisture dynamics, response conditions and its controls of 0–40 cm soil profile in the upslope (14°), midslope (9°), and downslope (4°) of a typical grassland inland river basin under bare ground (BG), stubble (SG), and natural grassland (CK) treatments. The results showed that soil water content and water storage increased in the downslope direction, and all showed as BG > SG > CK. The dry and wet changes in fast-changing layer (5 cm) and active layer (10 cm) were rapid, while soil moisture below 20 cm was relatively stable and fluctuated only in heavy or continuous rainfalls. The soil moisture response process varied greatly under different rainfall, rainfall intensity and antecedent soil moisture conditions, which explained 41.1% of the total difference. The rainfall replenishment threshold and the required initial soil profile water content of soil moisture response in 5 cm, 10 cm and 20 cm soil layers were 5.8 mm, 8.0 mm, 11.4 mm and 8.7 vol%, 9.4 vol%, 10.8 vol%, respectively. Soil properties, vegetation characteristics and topography could explain 38.8%, 14.5% and 5.6% of the soil moisture variation on the hillslope. In addition, under the comprehensive influence of environmental factors, changes in soil moisture of the upslope were significantly affected by soil sand content, the differences in the midslope were mainly due to soil clay content and belowground biomass, whereas the vegetation characteristics were the main factors in the downslope. This study can contribute to the further understanding of slope-scale ecohydrological processes and hydrological simulation of semi-arid grassland watersheds. • The response of soil moisture to rainfall under different vegetation treatments at different hillslope positions was investigated. • Rainfall recharge thresholds and initial soil profile water content for soil moisture responses at different soil depths were determined. • The effects of water condition, vegetation characteristics and soil properties on soil water responses at different hillslope locations were quantified. [ABSTRACT FROM AUTHOR]

The disinfection efficacy of slightly acidic electrolyzed water (SAEW) has been recognized in food industry. However, the application of single SAEW limited its disinfection potential. The efficacy of the two-step disinfection with SAEW for the reduction of L. monocytogenes contamination on different food raw materials was evaluated compared to the one-step disinfection with SAEW in this study. Results demonstrated that SAEW could reduce both the natural aerobic bacterial count and inoculated L. monocytogenes population on endive and chicken immediately after processing and SAEW with approximately 60 mg/L of available chlorine concentration (ACC) had equal or higher antibacterial efficacy compared to NaClO solutions with approximately 150 mg/L of ACC. Moreover, SAEW treatments could control the growth of microbial populations of L. monocytogenes during storage and the efficacy on the microbial reduction was associated to the initial populations. In addition, the SAEW-treated food raw materials were stored and disinfected again after storage and the results showed that the two-step disinfection method could decrease the survival populations of L. monocytogenes by 24.8%–99.6% compared to the one-step disinfection of SAEW. Therefore, considering storage habits, the two-step disinfection of SAEW may be a better choice in the disinfection of non-consumed-directly food raw materials. • A two-step disinfection of SAEW on L. monocytogenes on endive and chick was evaluated. • SAEW could reduce both the microbial contamination on endive and chicken before storage. • SAEW could control the growth of L. monocytogenes on endive and chicken during storage. • The two-step disinfection of SAEW is a better choice in the non-consumed-directly food materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fragment-based hit screening resulted in several fragment inhibitors of the ZIKV NS2B/NS3 protease. • Crystal structures of the ZIKV NS2B/NS3 protease in complex with a tetrapeptide and a fragment were determined, revealing the detailed but distinct protease-inhibitor interaction patterns. • A novel inhibitor with a higher ligand-binding efficiency was designed based on two complex structures. Zika virus (ZIKV) has been a serious public health problem, and there is no vaccine or drug approved for the prevention or treatment of ZIKV yet. The ZIKV NS2B/NS3 protease plays an important role in processing the virus precursor polyprotein and is thus a promising target for antiviral drugs development. In order to discover novel inhibitors of this protease, we carried out a fragment-based hit screening and characterized protein-inhibitor interactions using the X-ray crystallography together with isothermal titration calorimetry. We reported two high-resolution crystal structures of the protease (bZiProC143S) in complex with an active fragment as well as a tetrapeptide, revealing that there is domain swapping in the protein structures and two ligands only occupy the substrate-binding pocket of one copy in a symmetric unit. Based on the detailed binding modes of two ligands revealed by crystal structures, we designed a novel inhibitor which inhibits the NS2B/NS3 protease with a higher potency than the fragment and possesses a higher ligand-binding efficiency and a comparable IC 50 compared to the tetrapeptide. These results thus provide a structural basis and valuable hint for development of more potent inhibitors of the ZIKV NS2B/NS3 protease. [ABSTRACT FROM AUTHOR]

Denitrification is the most important process for nitrogen removal in eutrophic lakes and was mostly investigated in lake sediment. Denitrification could also be mediated by cyanobacterial aggregates, yet how this process impacts nitrogen (N) availability and the associated autotroph-heterotroph relationships within cyanobacterial aggregates has not been investigated. In this study, incubation experiments with nitrate amendment were conducted with Microcystis aggregates (MAs). Measurement of nitrogen contents, 16S rRNA-based microbial community profiling and metatranscriptomic sequencing were used to jointly assess nitrogen turnover dynamics, as well as changes in microbial composition and gene expression. Strong denitrification potential was revealed, and maximal N removal was achieved within two days, after which the communities entered a state of severe N limitation. Changes of active microbial communities were further promoted both with regard to taxonomic composition and transcriptive activities. Expression of transportation-related genes confirmed competition for N sources by Microcystis and phycospheric communities. Strong stress response to reactive oxygen species by Microcystis was revealed. Notably, interspecific relationships among Microcystis and phycospheric communities exhibited a shift toward antagonistic interactions, particularly evidenced by overall increased expression of genes related to cell lysis and utilization of cellular materials. Patterns of fatty acid and starch metabolism also suggested changes in carbon metabolism and cross-feeding patterns within MAs. Taken together, this study demonstrated substantial denitrification potential of MAs, which, importantly, further induced changes in both metabolic activities and autotroph-heterotroph interactions. These findings also highlight the key role of nutrient condition in shaping autotroph-heterotroph relationships. [Display omitted] • Microcystis aggregates have strong denitrification potential. • Denitrification shifted composition and gene expression of active communities. • Prolonged incubation promoted antagonistic autotroph-heterotroph relationships. • Changes in carbon metabolism and cross-feeding patterns within Microcystis aggregates also occurred. [ABSTRACT FROM AUTHOR]

The spatial compartmentalisation of biochemical signalling pathways is essential for cell function. Nesprins are a multi-isomeric family of proteins that have emerged as signalling scaffolds, herein, we investigate the localisation and function of novel nesprin-2 N-terminal variants. We show that these nesprin-2 variants display cell specific distribution and reside in both the cytoplasm and nucleus. Immunofluorescence microscopy revealed that nesprin-2 N-terminal variants colocalised with β-catenin at cell-cell junctions in U2OS cells. Calcium switch assays demonstrated that nesprin-2 and β-catenin are lost from cell-cell junctions in low calcium conditions whereas emerin localisation at the NE remained unaltered, furthermore, an N-terminal fragment of nesprin-2 was sufficient for cell-cell junction localisation and interacted with β-catenin. Disruption of these N-terminal nesprin-2 variants, using siRNA depletion resulted in loss of β-catenin from cell-cell junctions, nuclear accumulation of active β-catenin and augmented β-catenin transcriptional activity. Importantly, we show that U2OS cells lack nesprin-2 giant, suggesting that the N-terminal nesprin-2 variants regulate β-catenin signalling independently of the NE. Together, these data identify N-terminal nesprin-2 variants as novel regulators of β-catenin signalling that tether β-catenin to cell-cell contacts to inhibit β-catenin transcriptional activity. [ABSTRACT FROM AUTHOR]