Callous-unemotional traits and externalizing problem behaviors in left-behind preschool children: the role of emotional lability/negativity and positive teacher-child relationship.

BACKGROUND: Callous-unemotional traits and emotional lability/negativity of young children have been regarded as the markers of externalizing problem behaviors. Based on the sensitivity to threat and affiliative reward model and the general aggression model, emotional lability/negativity may act as a mediator in the relationship between callous-unemotional traits and externalizing problem behaviors. Additionally, a positive teacher-child relationship could act as a buffer given the parental absence in left-behind children. However, these links remain unexplored in left-behind preschool children. Therefore, this study explored the link between callous-unemotional traits of left-behind preschool children and externalizing problem behaviors, as well as the mediating role of emotional lability/negativity and the moderating role of a positive teacher-child relationship. METHOD: Data were collected on 525 left-behind children aged 3 to 6 years from rural kindergartens in China. Preschool teachers reported all data through an online survey platform. Moderated mediation analysis was performed to examine whether the mediated relation between callous-unemotional traits and externalizing problem behaviors was moderated by a positive teacher-child relationship. RESULTS: The results showed callous-unemotional traits significantly predicted externalizing problem behaviors and lability/negativity acted as a mediator, while a positive teacher-child relationship acted as a protective factor in moderating the relationship between callous-unemotional traits and emotional lability/negativity. This study identified a moderated mediation effect among the four variables in left-behind preschool children in China. CONCLUSION: The findings provide support for the advancement of theoretical foundations, and provide an avenue for further exploration to support the mental health and overall development of left-behind children during early childhood.

Lysosome-targeted ruthenium(II) complexes induce both apoptosis and autophagy in HeLa cells.

Ruthenium complexes with good biological properties have attracted increasing attention in recent decades. In this work, three ruthenium polypyridine complexes containing 5-fluorouracil derivatives as ligands, [Ru(bpy)2(L)]2+ (Ru1), [Ru(phen)2(L)]2+ (Ru2), [Ru(dip)2(L)]2+ (Ru3) (L = 1-((1,10-phenanthroline-5-amino) pentyl)-5-fluorouracil; bpy = 2,2'-bipyridine; phen =1,10-phenanthroline; dip = 4,7-diphenyl-1,10-phenanthroline), were synthesized and characterized. Based on in vitro cytotoxicity tests, Ru3 (IC50 = 7.35 ± 0.39 µM) showed the best anticancer activity among three compounds in the selected cell lines. It is worth noting that Ru3 also exerts less cytotoxicity on LO2 cell lines, with an IC50 value 5 times higher than that on HeLa cells, indicating its selective activity. Mechanism studies revealed that Ru3 can specifically target lysosomes and induce cell apoptosis in a caspase-dependent manner. Specifically, Ru3 can arrest cell cycle at the G0/G1 phase, increase the intracellular reactive oxygen species (ROS) level, and then damage DNA. In short, Ru3 can eventually cause cell death through the synergy of inducing apoptosis and autophagy, which was further proven by western blot assay results.

MEMS Deformable Mirrors for Space-Based High-Contrast Imaging.

Micro-Electro-Mechanical Systems (MEMS) Deformable Mirrors (DMs) enable precise wavefront control for optical systems. This technology can be used to meet the extreme wavefront control requirements for high contrast imaging of exoplanets with coronagraph instruments. MEMS DM technology is being demonstrated and developed in preparation for future exoplanet high contrast imaging space telescopes, including the Wide Field Infrared Survey Telescope (WFIRST) mission which supported the development of a 2040 actuator MEMS DM. In this paper, we discuss ground testing results and several projects which demonstrate the operation of MEMS DMs in the space environment. The missions include the Planet Imaging Concept Testbed Using a Recoverable Experiment (PICTURE) sounding rocket (launched 2011), the Planet Imaging Coronagraphic Technology Using a Reconfigurable Experimental Base (PICTURE-B) sounding rocket (launched 2015), the Planetary Imaging Concept Testbed Using a Recoverable Experiment - Coronagraph (PICTURE-C) high altitude balloon (expected launch 2019), the High Contrast Imaging Balloon System (HiCIBaS) high altitude balloon (launched 2018), and the Deformable Mirror Demonstration Mission (DeMi) CubeSat mission (expected launch late 2019). We summarize results from the previously flown missions and objectives for the missions that are next on the pad. PICTURE had technical difficulties with the sounding rocket telemetry system. PICTURE-B demonstrated functionality at >100 km altitude after the payload experienced 12-g RMS (Vehicle Level 2) test and sounding rocket launch loads. The PICTURE-C balloon aims to demonstrate 10 - 7 contrast using a vector vortex coronagraph, image plane wavefront sensor, and a 952 actuator MEMS DM. The HiClBaS flight experienced a DM cabling issue, but the 37-segment hexagonal piston-tip-tilt DM is operational post-flight. The DeMi mission aims to demonstrate wavefront control to a precision of less than 100 nm RMS in space with a 140 actuator MEMS DM.