Effect of Hindered Amine Light Stabilizer on Properties of HDPE/Kaolin Composites for Hydraulic Gate and its Mechanism Analysis

High density polyethylene (HDPE)/kaolin composites with different hindered Amine light stabilizers were prepared by blending granulation. The mechanical properties and dynamic thermodynamic changes before and after aging were discussed and studied. The precipitates were analyzed by FI-IR and H1-NMR, and the precipitation reason and anti-aging difference of different light stabilizers were discussed and compared. The results showed that the mechanical properties retention rates of light stabilizer 2020, light stabilizer 944, light stabilizer 123, light stabi-lizer 770 and light stabilizer 292 were 87.1%, 81.7% and 79.1%, respectively %Light stabilizer 2020 and light stabilizer 944 with large molecular weight are more easily compatible with the system, not easy to precipitate, and have a better an-ti-aging effect. At the same time, light stabilizer 2020 with dense hindered amine structure has excellent anti-aging effect. This study provides a reference for the selection of light stabilizer and failure analysis of light aging resistance of HDPE system.

Effective absorption of SO2 by imidazole-based PILs with multiple active sites: Thermodynamic and mechanical studies

In view of the environmental hazards caused by SO2, the development of efficient SO2 capture technology has important practical significance. In this work, a low viscosity protic ionic liquids containing imidazole, ether linkage, and tertiary amine structure, was synthesized by acid-base neutralization of tris(3,6-dioxaheptyl)amine (TMEA) and imidazole (Im) for SO2 absorption. The results showed that the solubility of SO2 in [TMEA][Im] reached 12.754 mol·kg-1 at 298.2 K and 100 kPa and the ideal selectivity of SO2/CO2(1/1) and SO2/H2S(1/1) are 141.6 and 11.8 at 100 kPa, respectively. Furthermore, [TMEA][Im] can be reused and the SO2 absorption performance was not significantly reduced after five cycles. In addition, the absorption of low-concentration SO2 (2000 ppm) in [TMEA][Im] was also tested. Further spectroscopic research and thermodynamic analysis suggested that the high SO2 uptake by [TMEA][Im] was caused by the synergistic effect of physical and chemical absorption.

Correction: Dinuclear cobalt complexes with a redox active biphenyl bridging ligand [Co2(BP)(tqa)2](PF6)2 (H4BP = 4,4′-bis(3-tert-butyl-1,2-catechol), tqa = tris(2-quinolylmethyl)amine): structure and magnetic properties

Correction for ‘Dinuclear cobalt complexes with a redox active biphenyl bridging ligand [Co2(BP)(tqa)2](PF6)2 (H4BP = 4,4′-bis(3-tert-butyl-1,2-catechol), tqa = tris(2-quinolylmethyl)amine): structure and magnetic properties’ by Yusaku Suenaga et al., Dalton Trans., 2021, DOI: 10.1039/d1dt00995h.

Dinuclear Cobalt Complexes with Redox Active Biphenyl Bridging Ligand [Co2(BP)(tqa)2](PF6)2 (H4BP = 4,4’-bis(3-tert-butyl-1,2-catechol), tqa = tris(2-quinolylmethyl)amine): Structure and Magnetic Properties

The biscatechol, H4BP (4,4’-bis(3-tert-butyl-1,2-catechol)) that connects two redox active catechol moieties directly was synthesized. Also, tpa (tris(2-pyridylmethyl)amine), bpqa (bis(2-pyridylmethyl)(2-quinolylmethyl)amine), pbqa ((2-pyridylmethyl)bis(2-quinolyl methyl)amine), and tqa (tris(2-quinolylmethyl)amine) were synthesized as terminal ligands...

Proline Protects Boar Sperm against Oxidative Stress through Proline Dehydrogenase-Mediated Metabolism and the Amine Structure of Pyrrolidine

Proline was reported to improve sperm quality in rams, stallions, cynomolgus monkeys, donkeys, and canines during cryopreservation. However, the underlying mechanism remains unclear. The aim of this study was to investigate the effect of proline on boar semen during liquid storage at 17 °C and explore the underlying mechanism. Freshly ejaculated boar semen was supplemented with different concentrations of proline (0, 25, 50, 75, 100, 125 mM) and stored at 17 °C for nine days. Sperm motility patterns, membrane integrity, ATP (adenosine triphosphate), reactive oxygen species (ROS), and GSH (glutathione) levels, and the activities of catalase (CAT) and superoxide dismutase (SOD) were evaluated after storage for up to five days. It was observed that boar sperm quality gradually decreased with the extension of storage time, while the ROS levels increased. Addition of 75 mM proline not only significantly improved sperm membrane integrity, motility, and ATP levels but also maintained the redox homeostasis via increasing the GSH levels and activities of CAT and SOD. When hydrogen peroxide (H2O2) was used to induce oxidative stress, addition of proline significantly improved sperm quality and reduced ROS levels. Moreover, addition of proline also improved sperm quality during the rapid cooling process. Notably, addition of DL-PCA (DL-pipecolinic acid) rescued the reduction of progressive motility and total motility caused by H2O2, and THFA (tetrahydro-2-furoic acid) failed to provide protection. Furthermore, addition of proline at 75 mM increased the activity of proline dehydrogenase (PRODH) and attenuated the H2O2-induced reduction in progressive motility. These data demonstrate that proline protects sperm against oxidative stress through the secondary amine structure and proline dehydrogenase-mediated metabolism.

Syntheses and Structure–Activity Relationships in Growth Inhibition Activity against Human Cancer Cell Lines of 12 Substituted Berberine Derivatives

In this study, quaternary berberine chloride is used as a lead compound to design and synthesize a series of berberine-12-amine derivatives to evaluate the growth inhibition activity against human cancer cell lines. Forty-two compounds of several series were obtained. The quaternary berberine-12-N,N-di-n-alkylamine chlorides showed the targeted activities with the IC50 values of most active compounds being dozens of times those of the positive control. A significant structure–activity relationship (SAR) was observed. The activities of quaternary berberine-12-N,N-di-n-alkylamine chlorides are significantly stronger than those of the reduced counterparts. In the range of about 6-8 carbon atoms, the activities increase with the elongation of n-alkyl carbon chain of 12-N,N-di-n-alkylamino, and when the carbon atom numbers are more than 6-8, the activities decrease with the elongation of n-alkyl carbon chain. The activities of the tertiary amine structure are significantly higher than that of the secondary amine structure.