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This study aimed to investigate the adsorption of heavy metal ions onto zwitterionic and anionic modified sierozem, dodecyl dimethyl betaine (zwitterionic modifier, BS) and sodium dodecyl sul-fate (anionic modifier, SDS), which were used to simultaneously modify sierozems. The adsorption characteristics of Cu2+and Cd2+on each composite modified sierozem were studied by batch method, and the effect of temperature, pH, and ionic strength on adsorption were compared. The following results were obtained: (1) the adsorption isotherms of Cu2+and Cd2+in different modified sierozems followed the Langmuir model. The adsorption capacities of Cu2+and Cd2+were in the order of BS+SDS-modified > BS-modified > unmodified sierozem. With the increase of modified proportion of SDS, the amount of Cu2+and Cd2+adsorbed onto BS+SDS-modified sierozem increased. Cu2+has a higher adsorption amount on the same modified sierozem than Cd2+. (2) The increase of temperature inhibited Cu2+and Cd2+adsorption in BS+SDS modified sierozems but promoted Cu2+and Cd2+adsorption in BS-modified and unmodified sierozems. Low ionic strength and high pH promoted the Cu2+and Cd2+adsorption in all tested modified sierozems. (3) The adsorption of Cu2+and Cd2+onto different sierozem samples showed a spontaneous, entropy- increasing, and endothermic process on CK and BS-modified sierozem and spontaneous, entropy-increasing, and exothermic process on BS+SDS-modified sierozem. The spontaneity and entropy of Cu2+adsorption were higher than those of Cd2+.

Objective: While the upregulation of cytochrome P450 family 24 subfamily A member 1 (CYP24A1)gene expression has been reported in colon cancer, its role in tumorigenesis remains largely unknown. In this study, we aimed to investigate the involvement of CYP24A1in Wnt pathway regulation viathe nuclear factor kappa B (NF-κB) pathway. Methods: The human colon cancer cell lines HCT-116 and Caco-2 were subjected to stimulation with interleukin-6 (IL-6) as well as tumor necrosis factor alpha (TNF-α), with subsequent treatment using the NF-κB pathway-specific inhibitor ammonium pyrrolidinedithiocarbamate (PDTC). Furthermore, CYP24A1 expression was subjected to knockdown viathe use of small interfering RNA (siRNA). Subsequently, NF-κB pathway activation was determined by an electrophoretic mobility shift assay, and the transcriptional activity of β-catenin was determined by a dual-luciferase reporter assay. A mouse ulcerative colitis (UC)-associated carcinogenesis model was established, wherein TNF-α and the NF-κB pathway were blocked by anti-TNF-α monoclonal antibody and NF-κB antisense oligonucleotides, respectively. Then the tumor size and protein level of CYP24A1 were determined. Results: IL-6 and TNF-α upregulated CYP24A1 expression and activated the NF-κB pathway in colon cancer cells. PDTC significantly inhibited this increase in CYP24A1 expression. Additionally, knockdown of CYP24A1expression by siRNA could partially antagonize Wnt pathway activation. Upregulated CYP24A1expression was observed in the colonic epithelial cells of UC-associated carcinoma mouse models. Anti-TNF-α monoclonal antibody and NF-κB antisense oligonucleotides decreased the tumor size and suppressed CYP24A1 expression. Conclusion: Taken together, this study suggests that inflammatory factors may increase CYP24A1 expression viaNF-κB pathway activation, which in turn stimulates Wnt signaling.

To study the adsorption characteristics of Cu2+by amphoteric and nanometer zero-valent iron (NZVI)-modified riverbank soil, we used dodecyl dimethyl betaine (BS-12) for amphoteric modification of bank soils from the Jialing River (Sichuan section). Then, NZVI was loaded on the BS-12-modified riverbank soils by liquid-phase reduction. The physicochemical characteristics of different BS-12-and BS-NZVI (BS-12 and NZVI)-modified riverbank soils and their adsorption differences were studied under various conditions (pH, ion strength, and temperature). In addition, the isothermic adsorption and thermodynamic characteristics of Cu2+on BS-12-and BS-NZVI-modified riverbank soils were analyzed. Results showed the following: (1) pH, cation exchange capacity and specific surface area (SBET) of different BS-12-and BS-NZVI-modified soils decreased, whereas their total organic carbon (TOC) increased. The surface of the original soils became smooth after BS-12 modification, whereas the surface of BS-12-modified soils became rough after loading with NZVI. NZVI was evenly distributed on the BS-NZVI-modified soil surface. (2) pH had minimal effect on the adsorption of Cu2+by different soil samples. The adsorption of Cu2+by different modified soils was promoted first and then restrained with the increase in ion strength. In the range of 20°C–40°C, the adsorption amount of Cu2+by different modified soils showed a positive temperature effect. (3) The adsorption isotherms of Cu2+for BS-12-and BS-NZVI-modified soils were all L-shaped, and the adsorption amount of Cu2+by different soil samples was ranked in the order of BS-NZVI modification > BS-12 modification > without modification. BS-NZVI-modified soil samples effectively improved the removal rate of Cu2+. The adsorption of Cu2+by different soil samples was a spontaneous, endothermic, and entropy-adding process. (4) TOC and SBETwere the key factors that determined the maximum adsorption amount of Cu2+by BS-12-and BS-NZVI-modified riverbank soils.

In this study, 40CrMnSiB steel cylindrical shells were tempered at 350, 500 and 600 °C to study the effect of tempering temperature on the dynamic process of expansion and fracture of the metal shell. A mid-explosion recovery experiment for the metal cylinder under internal explosive loading was designed, and the wreckage of the casings at the intermediate phase was obtained. The effects of different tempering temperatures on the macroscopic and microscopic fracture characteristics of 40CrMnSiB steel were studied. The influence of tempering temperatures on the fracture characteristic parameters of the recovered wreckage were measured and analyzed, including the circumferential divide size, the thickness and the number of the circumferential divisions. The results show that as the tempering temperature was increased from 350 to 600 °C, at first, the degree of fragmentation and the fracture characteristic parameters of the recovered wreckage changed significantly and then became essentially consistent. Scanning electron microscopy analysis revealed flow-like structure characteristics caused by adiabatic shear on different fracture surfaces. At the detonation initiation end of the casing, fracturing was formed by tearing along the crack, which existed a distance from the initiation end and propagated along the axis direction. In contrast, the fracturing near the middle position consists of a plurality of radial shear fracture units. The amount of alloy carbide that was precipitated during the tempering process increased continuously with tempering temperature, leading to an increasing number of spherical carbide particles scattered around the fracture surface.