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Objective To explore the role of pyruvate kinase M20 (PKM2)-regulated glycolysis on nod-like receptor protein 3 (NLRP3)- and absentin melanoma 2 (AIM2)-mediated inflammatory activation of macrophages in diabetic nephropathy (DN). Methods Renal biopsy samples from 30 DN patients and tumor-adjacent renal tissue samples from 20 renal cancer patients were collected for detection of the expressions of the glycolytic marker PKM2, the macrophage infiltration marker CD68 and tumor necrosis factor-α (TNF-α) using immunohistochemistry. The levels of TNF-α, interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) in serum samples from the DN patients and 20 healthy volunteers were detected by ELISA. In cultured mouse bone marrow-derived macrophages, the effects of mannitol, high-glucose exposure, high-glucose exposure plus PKM2 siRNA, and high-glucose exposure plus glycolysis inhibitor on the expression of PKM2, p-EIF2AK2, EIF2AK2, NLRP3 and AIM2 were detected using Western blotting; the secretion and mRNA expression of TNF-α, IL-1β and MCP-1 were detected by ELISA and RT-PCR, and the lactate content and glucose absorption of the cells were assayed using commercial detection kits. Results Compared with the tumor-adjacent renal tissues, the renal tissues from DN patients showed significantly increased expression of PKM2, CD68 and TNF-α (P < 0.01). In the cell cultures of macrophages, high glucose exposure obviously upregulated the cellular expression of PKM2, p-EIF2AK2, NLRP3 and AIM2 proteins (P < 0.01) and the mRNA expression of TNF-α, IL-1β and MCP-1 (P < 0.01) and increased the levels of TNF-α, IL-1β, MCP-1, lactic acid and glucose in the cell supernatant (P < 0.01). Transfection of the cells with PKM2 siRNA significantly inhibited inflammatory responses of the macrophages induced by high-glucose exposure. Conclusion High glucose stimulation can enhance the level of glycolysis in macrophages and promote the activation of inflammasomes and release of inflammatory cytokines through a mechanism involving the activation of PKM2-EIF2AK2 signaling pathway.

In this work, Ca(H2PO4)2 was used as a green corrosion inhibitor for AZ91D magnesium alloy in 3.5 wt% NaCl solution. The corrosion inhibition behavior and mechanism were analyzed using electrochemical tests, high-definition video measuring microscopy, scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The electrochemical testing results showed that the optimal corrosion inhibition concentration of Ca(H2PO4)2 was 0.6 g L−1, and the highest corrosion inhibition efficiency was 89.29% after 48 h immersion in the corrosive medium. Optical microscopy and SEM images showed that an obvious protective film formed on the Mg alloy surface in solution inhibited with Ca(H2PO4)2. EDS and XRD results showed that the protective layer was composed of Mg(OH)2 + MgHPO4 + Ca3PO4, and MgHPO4 played a major role. The precipitation mechanism of Ca(H2PO4)2 as a corrosion inhibitor was proposed. [ABSTRACT FROM AUTHOR]

After long-term operation, a variety of hidden defects will occur in hydraulic structures, which will endanger the safety of a water conservancy project. In particular, hidden defects located below the water surface cannot be easily recognized by conventional methods and thus constitute the main reason for occurrence of dangerous situations in such hydraulic structures. It is therefore necessary to carry out periodic checks on the underwater structures. Ground-penetrating radar (GPR) is a high-resolution, nondestructive technology for detection of underground objects using a high-frequency electromagnetic pulse, and has been extensively applied to a variety of fields such as engineering/geologic exploration, underground archaeological survey, detection of scour holes around bridge piers, etc. In order to investigate the capability of GPR in detecting hidden dangers to underwater hydraulic structures, the authors have conducted GPR application-related experiments for more than 20 hydraulic projects since 1996, and in order for the GPR application to be successful in narrow spaces such as lock chambers, the authors also designed an antenna that can be directly operated on the water's surface. Experimental results demonstrate that GPR can be used not only to detect hidden dangers with high precision, such as uneven settlement and cracking at impervious blanket or apron water bottoms, but also to detect hidden dangers to underwater hydraulic structures, such as damage of reverse filter below the sloping clay core of a dam, settlement and cracking of the antiseepage geomembrane at the bottom of a reservoir, concentrated seepage channel, etc. The application effect will be demonstrated in this paper based on some practical examples of using the GPR technique for such types of detection. CE Database subject headings: Water resources; Hydraulic structures; Underwater structures; Geophysical surveys; Radar; Structural safety; Research; Case reports.

Tec kinase is an important mediator in inflammatory immune response that enhances the activity of neutrophils and macrophages. However, information on its function in lipopolysaccharide- (LPS-) induced acute kidney injury (AKI) is limited. This study is aimed at determining whether Tec kinase was a regulator in AKI. An AKI model in mice was successfully established using intraperitoneal LPS. Results showed that the serum levels of creatinine (Cr), blood urea nitrogen (BUN), and cystatin-C (Cys-C) increased after intraperitoneal LPS injection. Renal tissue sustained significantly severe injury as measured by pathological scores. Pretreatment with LFM-A13 improved the function of the kidney in mice and decreased the renal injury score. Enzyme-linked immunosorbent assay showed that LFM-A13 significantly reduced the release of IL-1 β and TNF- α in mice exposed to LPS. LFM-A13 can evidently abrogate the expression of Tec protein, MyD88, TLR4, NF- κ B p65, and Tec's phosphorylated protein as determined by Western blot. Immunohistochemistry analysis revealed that LFM-A13 markedly downregulated the expression of Tec kinase in renal tubular epithelial cells. In vitro, Tec kinase protein was expressed highly in NRK-52E cells after LPS exposure. Tec-siRNA also decreased IL-1 β and TNF- α production and obviously abolished phospho-p65 and phospho-I κ B α expression in NRK-52E cell stimulated by LPS; however, Tec-siRNA increased the I κ B α level. Altogether, these data suggested that Tec kinase can be a modulating protein in AKI through TLR4/NF- κ B activation., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper., (Copyright © 2020 Wei Zhang et al.)