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In the Yellow River Delta of China, soil salinization is of serious concern from both agricultural and environmental perspectives. In this study we investigated the microstructural characteristics of saline‐alkali soils in this region and explored the influence of frost heave on soil microstructure. Soil mineral composition, pore distribution, particle arrangement, and pore characteristics were measured using X‐ray diffraction (XRD), mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM). Soil pore characteristics, overall porosity, and unconfined compressive strength (UCS) were measured at water content of 10, 15, 20, 25% (w/w) before and after freezing at −10°C. The results showed that deterioration of soil physical properties was largely caused by dense particle arrangement, high proportion of ultra‐micropore‐specific surface area, and poor pore distribution, rather than mineral content or particle size distribution. The microstructure of saline‐alkali soil was greatly improved by frost heave with the overall porosity and UCS of frost heave‐treated soil samples significantly higher than for the control. Moreover, particle cementation decreased with increasing soil water content. This study demonstrated that a combination of XRD, SEM, and MIP offers accurate evaluation of the microstructural characteristics of saline‐alkali soils, and frost heave may serve as an economically sustainable and technically feasible method for saline‐alkali soil amelioration in the Yellow River Delta. [ABSTRACT FROM AUTHOR]

Background: Previous studies have demonstrated that β2-microglobulin (β2M) promotes the growth and survival of a variety of cancer cells and has different regulatory effects on the expression of Bcl-2 and HER2 in HER2- breast cancer cells. However, β2M-mediated signaling in ER+ and ER- breast cancer with HER2- remains unclear.Methods: β2M expression vector and siRNA were transfected into two types of HER2- breast cancer cells, and the possible relevant signaling molecules were subsequently analyzed by real-time PCR and western blotting. These signaling molecules were also analyzed by real-time PCR and immunohistochemistry (IHC) in two types of HER2- breast cancer tissues, and the associations between β2M and these signaling molecules were assessed using Spearman's correlation analysis.Results: β2M silencing downregulated p-SGK1/SGK1 levels and Bcl-2 expression, and β2M overexpression downregulated p-CREB/CREB and significantly upregulated p-SGK1/SGK1 levels and Bcl-2 expression, and both resulting processes did not affect HER2, HIF-1α, VEGF, and ERK signaling in ER+ breast cancer cells with HER2-. β2M silencing upregulated p-CREB/CREB and VEGF protein and significantly downregulated p-ERK/ERK levels, and β2M overexpression downregulated p-CREB/CREB and VEGF, significantly upregulated p-ERK/ERK levels, and both resulting processes did not affect HIF-1α and SGK1 signaling in ER- breast cancer cells with HER2-. β2M expression was positively correlated with p-CREB, p-SGK1, and Bcl-2 expression and had no correlation with HIF-1α, VEGF, and p-ERK1/2, whereas p-SGK1 exhibited a significantly positive correlation with Bcl-2 expression in cancer tissues of patients with luminal A breast cancer, which coincide with the results obtained from the same molecular types of breast cancer cells except CREB signaling. However, β2M expression did not show a significant correlation with HIF-1α, p-CREB, VEGF, p-SGK1, p-ERK1/2, and Bcl-2 expression in cancer tissues of patients with basal-like breast cancer, which was discordant with the results obtained from the same molecular types of breast cancer cells.Conclusions: β2M has a different molecular regulatory mechanism between ER+ and ER- breast cancer with HER2-, and it may promote tumor survival through the SGK1/Bcl-2 signaling pathway in ER+ breast cancer with HER2- and has no regulatory effects on ER- breast cancer with HER2-. [ABSTRACT FROM AUTHOR]