Photodissociation of carbon dioxide (CO2) has long been assumed to proceed exclusively to carbon monoxide (CO) and oxygen atom (O) primary products. However, recent theoretical calculations suggested that an exit channel to produce C + O2 should also be energetically accessible. Here we report the direct experimental evidence for the C + O2 channel in CO2 photodissociation near the energetic threshold of the C((3)P) + O2(X(3)Σ(g)(-)) channel with a yield of 5 ± 2% using vacuum ultraviolet laser pump-probe spectroscopy and velocity-map imaging detection of the C((3)PJ) product between 101.5 and 107.2 nanometers. Our results may have implications for nonbiological oxygen production in CO2-heavy atmospheres.
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http://dx.doi.org/10.1126/science.1257156 | DOI Listing |
Anal Chem
January 2025
Yunnan Key Laboratory of Modern Separation Analysis and Substance Transformation, College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, Yunnan Province, P. R. China.
Early and portable detection of pathogenic bacteria is crucial for ensuring food safety, monitoring product quality, and tracing the sources of bacterial infections. Moving beyond traditional plate-culture counting methods, the analysis of active bacterial components offers a rapid means of quantifying bacteria. Here, metal-organic framework (MOF)-derived NiCo-layered double hydroxide nanosheets (LDHs), synthesized via the Kirkendall effect, were employed as highly effective oxidase mimics to generate reactive oxygen species (ROS).
View Article and Find Full Text PDFPlant Cell Rep
January 2025
Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, APC Road, Kolkata, 700 009, India.
Melatonin increases Pb tolerance in P. ovata seedlings via the regulation of growth and stress-related phytohormones, ROS scavenging and genes responsible for melatonin synthesis, metal chelation, and stress defense. Lead (Pb) is a highly toxic heavy metal that accumulates in plants through soil and air contamination and impairs its plant growth and development.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Sichuan University, School of Chemical Engineering, No.24 South Section 1, Yihuan Road, 610065, Chengdu, CHINA.
Covalent organic frameworks (COFs) are often employed in oxygen reduction reactions (ORR) for hydrogen peroxide production due to their tunable structures and compositions. However, COF electrocatalysts require precise structural engineering, such as heteroatoms or metal site doping, to modulate the reaction pathway during the ORR process. In this work, we designed a tetraphenyl-p-phenylenediamine based COF electrocatalyst, namely TPDA-BDA, which exhibited excellent two-electron (2e) ORR performance with high H2O2 selectivity of 89.
View Article and Find Full Text PDFJ Med Chem
January 2025
Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning Province; Engineering Research Center of Natural Medicine Active Molecule Research & Development, Liaoning Province; Key Laboratory of Natural Bioactive Compounds Discovery & Modification, Shenyang; School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, China.
Thioredoxin reductase 1 (TrxR1) is an important therapeutic target for nonsmall cell lung cancer (NSCLC) treatment due to its overexpression in NSCLC cells. In this work, to address the deficiency that sesquiterpene lactone containing α-methylene-γ-lactone moiety was rapidly metabolized by endogenous nucleophiles, series of novel thioether derivatives were designed and synthesized based on a reactive oxygen species (ROS)-triggered prodrug strategy. Among them, prodrug exhibited potent cytotoxicity against NSCLC cells and better release rates in response to ROS.
View Article and Find Full Text PDFCancer Med
February 2025
Department of General Surgery, The First People's Hospital of Baiyin (Third Affiliated Hospital of Gansu University of Traditional Chinese Medicine), Baiyin, China.
Background: Photodynamic therapy (PDT) is a noninvasive cancer treatment that works by using light to stimulate the production of excessive cytotoxic reactive oxygen species (ROS), which effectively eliminates tumor cells. However, the therapeutic effects of PDT are often limited by tumor hypoxia, which prevents effective tumor cell elimination. The oxygen (O) consumption during PDT can further exacerbate hypoxia, leading to post-treatment adverse events.
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