Sc-Catalyzed Asymmetric [2 + 2] Annulation of 2-Alkynylnaphthols with Dienes to Access Cyclobutene Frameworks.

Herein, we introduce a scandium-catalyzed synthetic strategy that provides access to a diverse and functionalized array of cyclobutene frameworks adorned with a quaternary carbon center. This approach broadens the synthetic repertoire of 2-alkynylnaphthols with alkenes, offering a versatile platform for the construction of complex molecular architectures. The asymmetric catalytic [2 + 2] cycloaddition reaction demonstrates a wide substrate scope and an impressive functional group tolerance, yielding products with high efficiency, up to 97% yield, and excellent enantiomeric excess of up to 97%.

Silicate-Confined Hydrogen on Nanoscale Zerovalent Iron for Efficient Defluorination Reactions.

Defluorination reactions are increasingly vital due to the extensive use of organofluorine compounds with robust carbon-fluorine (C-F) bonds; particularly, the efficient defluorination of widespread and persistent per- and polyfluoroalkyl substances under mild conditions is crucial due to their accumulation in the environment and human body. Herein, we demonstrate that surface-modified silicate of pronounced proton affinity can confine active hydrogen (•H) onto nanoscale zerovalent iron (nZVI) by withdrawing electrons from nZVI to react with bound protons, generating confined active hydrogen (•H) for efficient defluorination under ambient conditions. The exposed silicon cation (Si) of silicate functions as a Lewis acid site to activate the C-F bond by forming Si.

DECT sparse reconstruction based on hybrid spectrum data generative diffusion model.

Purpose: Dual-energy computed tomography (DECT) enables the differentiation of different materials. Additionally, DECT images consist of multiple scans of the same sample, revealing information similarity within the energy domain. To leverage this information similarity and address safety concerns related to excessive radiation exposure in DECT imaging, sparse view DECT imaging is proposed as a solution.

The effects of mobile phone addiction on learning engagement of Chinese college students - the mediating role of physical activity and academic self-efficacy.

Background: With the widespread adoption of smartphones, mobile phone addiction has increasingly gained prominence among Chinese college students, exerting a profound and detrimental impact on their learning engagement. This study employs self-determination theory as a framework to examine the mechanisms through which mobile phone addiction affects students' learning engagement. Specifically, it examines the mediating effects of physical activity and academic self-efficacy in this relationship.

Virulence Characterization and Population Structure of f. sp. in Henan Province, China.

Wheat stripe rust, caused by f. sp. (), poses a significant threat to wheat production, particularly in Henan province, which produces more than 36 million tons of wheat grain every year, the highest production among all provinces in China.