Significance of northwest axis on neonatal electrocardiograms.

Purpose: Northwest axis on an electrocardiogram is conventionally thought to be associated with CHD, but there is a paucity of data regarding the types and incidence of CHD associated with this finding. The purpose of this study was to report the types and incidence of CHD found at our institution to determine the efficacy of electrocardiograms as a screening test in infants.

Methods: Retrospective, single-centre study of all infants ≤ 60 days of age who underwent a first-time electrocardiogram from 2015 to 2021.

Main chain selective polymer degradation: controlled by the wavelength and assembly.

The advent of reversible deactivation radical polymerization (RDRP) revolutionized polymer chemistry and paved the way for accessing synthetic polymers with controlled sequences based on vinylic monomers. An inherent limitation of vinylic polymers stems from their all-carbon backbone, which limits both function and degradability. Herein, we report a synthetic strategy utilizing radical ring-opening polymerization (rROP) of complementary photoreactive cyclic monomers in combination with RDRP to embed photoresponsive functionality into desired blocks of polyvinyl polymers.

Access to Main-Chain Photoswitching Polymers via Hydroxyl-yne Click Polymerization.

Main-chain stimuli-responsive polymers synthesized via polymerization techniques that do not rely on metal-based catalysis are highly desirable for economic reasons and to avoid metal-polymer interactions. Herein, we introduce a metal-free head-to-tail organobase-catalyzed hydroxyl-yne click polymerization of an AB-type monomer to realize photoswitchable polymers featuring α-bismines as main-chain repeating units. The prepared main-chain α-bisimine-based polymers show excellent photoswitching in solution.