BACKGROUND:In the fluorine-containing acidic environment, it is unclear whether Damon copper- nickel-titanium arch wire can have a corrosion resistance similar to conventional nickel-titanium arch wire and whether copper ion wil affect its corrosion resistance. OBJECTIVE: To evaluate the corrosion resistance of 3M nickel-titanium arch wires and Damon copper-nickel-titanium arch wires in artificial saliva with different fluoride and pH. METHODS:Potentiodynamic polarization curves of 3M nickel-titanium arch wires and Damon copper-nickel-titanium arch wires were measured in four kinds of artificial saliva (pH=7; pH=7, 0.2% fluoride; pH=7, 0.5% fluoride; pH=5, 0.5% fluoride). Then, the corrosion potential, corrosion current density and polarization resistance were acquired, and scanning electron microscope was used for morphological observation after corrosion. RESULTS AND CONCLUSION: In neutral (pH=7) artificial saliva, 0.2% fluoride ions added could shift up the Damon specimen polarization curve, increase the corrosion cerrent density and reduce the polarization resistance (P < 0.05); under the scanning electron microscope, corrosion was observable on the specimen surface. But 3M specimen polarization curve did not move, corrosion current density and polarization resistance substantialy unchanged (P > 0.05), and no significant corrosion was produced. When fluoride concentration was increased to 0.5%, the polarization curves of two kinds of the specimens moved, the corrosion cerrent density increased, the polarization resistance decreased (P < 0.05), and there was significant presence of corrosion on the specimen surface. When pH=5, corrosion phenomenon was more pronounced. These findings suggest that low concentrations fluoride cannot affect corrosion resistance of 3M arch wire, but can reduce the corrosion resistance of Damon arch wire; high concentrations of fluoride and acid can both reduce their corrosion resistance. In addition, the corrosion resistance of 3M arch is stronger than that of Damon arch wire.

Objective To characterize the distribution and assess the exposure to phthalic acid esters （PAEs） in the indoor dust of Shanghai City. Methods Samples were collected from 33 sampling sites， including homes， hotels， offices and public places， in Shanghai in 2018， 2019， and 2020. The samples were pretreated by 100 sieves， extracted and concentrated， and then analyzed by gas chromatography-mass spectrometry in selected ion mode （SIM）. Results Results on the characteristics of PAEs in indoor dust in different places showed that concentrations of PAEs were in a range of <0.01-2 464 mg·kg^-1.The average concentration of 16 PAEs was 613 mg·kg^-1. Bis（2-ethylhexyl） phthalate （DEHP）， di-iso-butyl phthalate （DiBP）， di-n-butyl phthalate （DBP） and di-n-octyl phthalate （DnOP） were the main components of PAEs in indoor dust， accounting for approximately 99.5% of 16 PAEs. The intake of DEHP， DBP， DEP and BBP was lower than the tolerable daily intake （TDI） and reference doses （RfD） set by EU CSTEE and U.S. EPA. Conclusion Average daily dose （ADD） via indoor dust is estimated， and the order of intake through different pathways is hand-oral intake>skin contact>respiratory inhalation. Exposure risk of PAEs in children is greater than that in adults.

Metastatic triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer. Combination of systemic chemotherapy and immune checkpoint blockade is effective but of limited benefit due to insufficient intratumoral infiltration of cytotoxic T lymphocytes (CTLs) and the accumulation of immunosuppressive cells. Herein, we designed a lenvatinib- and vadimezan-loaded synthetic high-density lipoprotein (LV-sHDL) for combinational immunochemotherapy of metastatic TNBC. The LV-sHDL targeted scavenger receptor class B type 1-overexpressing 4T1 cells in the tumor after intravenous injection. The multitargeted tyrosine kinase inhibitor (TKI) lenvatinib induced immunogenic cell death of the cancer cells, and the stimulator of interferon genes (STING) agonist vadimezan triggered local inflammation to facilitate dendritic cell maturation and antitumor macrophage differentiation, which synergistically improved the intratumoral infiltration of total and active CTLs by 33- and 13-fold, respectively. LV-sHDL inhibited the growth of orthotopic 4T1 tumors, reduced pulmonary metastasis, and prolonged the survival of animals. The efficacy could be further improved when LV-sHDL was used in combination with antibody against programmed cell death ligand 1. This study highlights the combination use of multitargeted TKI and STING agonist a promising treatment for metastatic TNBC.