A Quantitative Study of the Halogenophilic Nucleophilic Substitution (S2X) Reaction and Chalcogenophilic Nucleophilic Substitution (S2Ch) Reaction.

Halogenophilic nucleophilic substitution (S2X) has a distinctly different reaction pathway compared to the bimolecular nucleophilic substitution reaction (S2), but they can lead to the same reaction product. However, their differences can be distinguished by studying stereoselective reactions in which both reaction pathways are possible. Herein, we utilize the stereospecific nature of S2 and the presence of a pro-chiral anion intermediate in S2X to conduct a quantitative study in which both S2 and S2X reactions exist.

Selective laser melting of titanium matrix composites: An in-depth analysis of materials, microstructures, defects, and mechanical properties.

This paper provides an in-depth review of the advancements and challenges associated with Titanium Matrix Composites (TMCs) in Selective Laser Melting (SLM). Material selection, SLM processing parameters, and their influence on the microstructure and properties of TMCs are discussed. The relationship between processing parameters, material characteristics, and the development of defects such as balling, porosity, and cracking is examined.

Extensive Q-factor tuning for leaky modes with minimal frequency variation in asymmetric slab grating structures.

We investigated an asymmetric slab grating structure to achieve significant tuning of the quality (Q) factor for a leaky mode while minimizing frequency variation. This structure comprises two identical gratings placed on the top and bottom of a slab waveguide, with one grating laterally shifted to introduce asymmetry. Simulations demonstrate that lateral shifting of one grating induces extensive changes in the Q-factor with minimal frequency variation, particularly near the band-flip filling fraction because the band-flip filling fraction remains unaffected by the shifting.

Demographic and lifestyle factors associated with perception about risk of passive smoking in the Malaysian adolescent population.

Aims: Exposure to passive smoking among adolescents is a public health concern. This study aims to explore demographic and lifestyle factors associated with perception of passive smoking risk and the mediating effects of exposure to anti-smoking advertisements and education about the dangers of smoking on the relationship between grade levels and the perception.

Method: Data from the Tobacco and E-Cigarette Survey among Malaysian Adolescents ( = 13,117) were analysed.

Impact of Astigmatism on Axial Elongation in School-Age Children: A Five-Year Population-Based Study in Tianjin, China.

Purpose: To investigate the progression rates of axial length (AXL) among school-age children with baseline astigmatism and spherical ametropia.

Methods: Annual vision screenings were conducted at seven schools in Tianjin, China, from 2018 to 2022. Ocular biometry and non-cycloplegic autorefraction were collected.