Kui Zhao

Recycled concrete fines (RCFs) have the potential to serve as a supplementary cementitious material (SCM) after carbonation. Traditionally, carbonation of RCFs results in calcium carbonate primarily in the form of calcite, which significantly limits the development of RCFs as an SCM. In this research, a wet grinding carbonation (WGC) technique was introduced to enhance the reactivity of RCFs. The research indicates that RCFs after WGC exhibit a finer particle size and a larger specific surface area. The carbonation products include calcite with smaller grains, metastable calcium carbonate, and nanoscale silica gel and Al-Si gel. When RCF-WGC is used as an SCM in ordinary Portland cement (OPC), it significantly promotes the hydration of the cement paste, as evidenced by the advancement and increased intensity of the exothermic peaks of aluminates and silicates. RCF-WGC can significantly enhance the compressive strength of hydrated samples, particularly at early ages. Specifically, at a curing age of 1 day, the compressive strength of WGC5, WGC10, and WGC20 samples increased by 9.9%, 22.5%, and 7.7%, respectively, compared to the Ref sample (0% RCF-WGC). At a curing age of 3 days, the compressive strength of the WGC5, WGC10, and WGC20 samples showed even more significant improvements, increasing by 20.8%, 21.9%, and 11.8%, respectively. The performance enhancement of the WGC samples is attributed to the chemical reactions involving nanoscale silica gel, Al-Si gel, and calcium carbonate in the RCFs. When RCF-WGC is used as an SCM to replace 5%, 10%, and 20% of cement, it can reduce carbon emissions by 27.5 kg/t, 55 kg/t, and 110 kg/t, respectively. Large-scale application of RCFs as a high-value SCM can significantly reduce the life-cycle carbon emissions of the cement industry, contributing to the achievement of carbon peaking in China’s cement sector.

The Procapra przewalskii inhabits in a selenium (Se)-deprived environment in long-term, but they have no pathological manifestations due to the Se deprivation. This study aimed to reveal the underlying adaptation induced by Se deprivation. In the analysis, a total of 93 significantly changed metabolites were identified in positive and negative ion modes, including 46 upregulated and 47 downregulated compounds in the Se-deprived group. The differential metabolites were annotated as the major molecules in bile acid biosynthesis, biosynthesis of unsaturated fatty acids, and pyrimidine metabolism, respectively. This study systematically analyzed the serum metabolomics characteristics of P. przewalskii under Se-deprived conditions for the first time, providing a basis for further understanding of the metabolic mechanism of P. przewalskii in the Se-deprived environment.

The Przewalski’s Gazelles (P. przewalskii) are affected by disorders that are characterized by deprived appetites, pica, emaciation and dyskinesia. The purpose of this study was to investigate the possibility of high molybdenum (Mo) in forage leading to copper (Cu) deprivation. The mineral contents in forage, soil, and samples of hair and blood from affected ranges were compared to healthy pasture. Blood parameters were also determined. Our results showed that the mean content of Mo in forage and soil in studied pasture was 5.17 and 4.17 μg/g, respectively. The Cu to Mo ratio in forage from affected and healthy areas was 1.26 and 5.89 μg/g, respectively. The Cu concentrations in hair and blood from gazelles in affected pasture were extremely lower (p < 0.01) than those in unaffected animals. The Mo contents in hair were higher (p < 0.01) than those in unaffected gazelles. The levels of Hb, RBC, PCV, MCV, and MCH in unaffected gazelles were significantly lower (p < 0.01) than those in unaffected gazelles. The levels of TP, ALB and GLB in blood were significantly lower (p < 0.01) than those in unaffected gazelles, while the levels of AST, LDH, CPK and ALP in serum were significantly higher (p < 0.01) than those in unaffected gazelles. The activities in serum T-AOC, SOD, GSH-Px, and CAT in affected gazelles were extremely lower (p < 0.01) than those in unaffected gazelles, while MDA was significantly higher (p < 0.01) than that in unaffected gazelles. Supplementation in copper sulphate (CuSO₄) has prevented and cured this disorder. In summary, high molybdenum in feed and soil may lead to secondary Cu deficiency in gazelles, which can be alleviated by supplement of copper sulfate.