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Photosystem II (PSII) uses light energy to oxidize water and to reduce plastoquinone in the photosynthetic electron transport chain. O is produced as a byproduct. While most members of the PSII research community agree that O originates from water molecules, alternative hypotheses involving bicarbonate persist in the literature. In this perspective, we provide an overview of the important roles of bicarbonate in regulating PSII activity and assembly. Further, we emphasize that biochemistry, spectroscopy, and structural biology experiments have all failed to detect bicarbonate near the active site of O evolution. While thermodynamic arguments for oxygen-centered bicarbonate oxidation are valid, the claim that bicarbonate is a substrate for photosynthetic O evolution is challenged.
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http://dx.doi.org/10.1007/s11120-024-01111-8 | DOI Listing |
Crit Care Med
September 2025
Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN.
ACS Appl Mater Interfaces
September 2025
The Steve Sanghi College of Engineering, Mechanical Engineering, Northern Arizona University, Flagstaff, Arizona 86011, United States.
This study investigates the HO and CO sorption behavior of two chemically distinct polystyrene-divinylbenzene-based ion exchange sorbents: a primary amine and a permanently charged strong base quaternary ammonium (QA) group with (bi)carbonate counter anions. We compare their distinct interactions with HO and CO through simultaneous thermal gravimetric, calorimetric, gas analysis, and molecular modeling approaches to evaluate their performance for dilute CO separations like direct air capture. Thermal and hybrid (heat + low-temperature hydration) desorption experiments demonstrate that the QA-based sorbent binds both water and CO more strongly than the amine counterparts but undergoes degradation at moderate temperatures, limiting its compatibility with thermal swing regeneration.
View Article and Find Full Text PDFDiabetes Obes Metab
September 2025
Department of Applied Health Sciences, University of Birmingham, Birmingham, UK.
Aim: Sodium-glucose co-transporter-2 inhibitors (SGLT2i) offer significant cardiorenal benefits for people with type 2 diabetes (PwT2D). However, concerns remain regarding their association with diabetes-related ketoacidosis (DKA). (1) To compare demographics, precipitating factors, biochemical features, management, and outcomes of acute DKA admissions between SGLT2i users (n = 267) and non-users (n = 793) with T2D.
View Article and Find Full Text PDFMol Genet Metab Rep
December 2025
Pediatric Critical Care Medicine, Department of Pediatrics NewYork-Presbyterian Morgan Stanley Children's Hospital, Columbia University Medical Center, New York, NY, United States of America.
encodes NADH: ubiquinone oxidoreductase core subunit V1, a key component of mitochondrial Complex 1. Biallelic pathogenic variants in this gene produce a broad and variable phenotypic spectrum in affected individuals, including ophthalmoplegia, developmental delays, brain imaging abnormalities, and recurrent episodes of emesis and lactic acidemia. We report female siblings compound heterozygous for two missense variants (Arg40Gln, Val245Met) in with unusual presentations of this condition.
View Article and Find Full Text PDFFront Pediatr
August 2025
Department of Pediatrics, Shantou Central Hospital, Shantou, Guangdong, China.
Background: Since 2019, COVID-19 has substantially impacted global public health. Although pediatric cases generally manifest with mild symptoms, severe and even fatal outcomes have occurred. Despite the decreased viral transmissibility and pathogenicity observed in the post-pandemic era, identifying early clinical indicators for severe pediatric COVID-19 remains crucial.
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