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Plant oil adjuvants are widely used to improve the utilization rate of pesticides. In this study, the uptake, translocation, and terminal residue of chlorantraniliprole and difenoconazole spraying with plant oil adjuvant in rice (Oryza sativa L.) were evaluated. After being mixed with the tank-mixed plant oil adjuvant, the cuticular wax of rice leaf was destroyed, which decreased the hydrophobicity of the rice leaf and facilitated the wetting, spreading, and penetration of pesticides onto the rice leaf. Additionally, the adjuvant promoted the translocation of difenoconazole from leaves to stems, but had little effect on the translocation of difenoconazole from leaves to roots, while inhibiting chlorantraniliprole translocation. Although adjuvant increased the initial deposition of chlorantraniliprole and difenoconazole on rice, the terminal residue was not significantly affected. The findings can promote the safe use of chlorantraniliprole and difenoconazole in rice production, especially when used with plant oil adjuvants. In the future, studies on more rice cultivars will be necessary to determine the generality of the conclusions.

Magnesium alloys are used as bone implants because of their good biocompatibility and degradability. However, due to the rapid and uneven degradation, its clinical application is limited. To improve the corrosion resistance of medical magnesium alloys, a novel technique of semisolid powder molding was used to prepare Mg-6Zn alloy, and then microarc oxidation (MAO) was firstly applied to modify the surface. In this study, the effects of different current densities (4, 6, 8 A/dm2) and microarc oxidation time (8, 14, 20 min) on the phase composition, thickness, density, microstructure, roughness, and corrosion resistance of MAO film were systematically studied, and then the optimized parameters were obtained. Finally, the optimized coating's biocompatibility (cytotoxicity, cell adhesion, hemolysis, osteogenic differentiation) was evaluated. The results show that the MAO film mainly comprises α-Mg, MgO, and Mg2SiO4. The film’s roughness, microhardness, and thickness increase with the current density and oxidation time. The lowest electrochemical corrosion rate of the coating is (2.3 ± 0.5 × 10–4mm/year under the parameter of 6 A/dm2-20 min, which decreases by about 3 orders of magnitude compared with naked Mg-6Zn (0.32 ± 0.06 mm/year). The optimized microarc oxidation parameter is 6 A/dm2-20 min, with a thickness of 18 ± 1.45 μm, and microhardness of 339.6 ± 9.09 HV (increases by 165.3%). Additionally, the cytotoxicity and hemolysis rate of naked and coated Mg-6Zn were reduced, but the cell viability and adhesion as well as the differentiation of osteoblast cells of coated Mg-6Zn were improved, exhibiting better biocompatibility. Therefore, semisolid powder molding can be used to prepare medical Mg alloys with high performance, and MAO improves corrosion resistance greatly.

ABSTRACTThe tumor suppressor protein p53 interacts with DNA in a sequence-dependent manner. Thousands of p53 binding sites have been mapped genome-wide in normal and cancer cells. However, the way p53 selectively binds its cognate sites in different types of cells is not fully understood. Here, we performed a comprehensive analysis of 25 published p53 cistromes and identified 3,551 and 6,039 ‘high-confidence’ binding sites in normal and cancer cells, respectively. Our analysis revealed 2 distinct epigenetic features underlying p53-DNA interactions in vivo. First, p53 binding sites are associated with transcriptionally active histone marks (H3K4me3 and H3K36me3) in normal-cell chromatin, but with repressive histone marks (H3K27me3) in cancer-cell chromatin. Second, p53 binding sites in cancer cells are characterized by a lower level of DNA methylation than their counterparts in normal cells, probably related to global hypomethylation in cancers. Intriguingly, regardless of the cell type, p53 sites are highly enriched in the endogenous retroviral elements of the ERV1 family, highlighting the importance of this repeat family in shaping the transcriptional network of p53. Moreover, the p53 sites exhibit an unusual combination of chromatin patterns: high nucleosome occupancy and, at the same time, high sensitivity to DNase I. Our results suggest that p53 can access its target sites in a chromatin environment that is non-permissive to most DNA-binding transcription factors, which may allow p53 to act as a pioneer transcription factor in the context of chromatin.