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New particle formation via the ion-mediated sulfuric acid and ammonia molecular clustering mechanism remains the most widely observed and experimentally verified pathway. Recent laboratory and molecular level observations indicate iodine-driven nucleation as a potentially important source of new particles, especially in coastal areas. In this study, we assess the role of iodine species in particle formation using the best available molecular thermochemistry data and coupled to a detailed 1-d column model which is run along air mass trajectories over the Southern Ocean and the coast of Antarctica. In the air masses traversing the open ocean, ion-mediated SA-NH clustering appears insufficient to explain the observed particle size distribution, wherein the simulated Aitken mode is lacking. Including the iodine-assisted particle formation improves the modeled Aitken mode representation with an increase in the number of freshly formed particles. This implies that more particles survive and grow to Aitken mode sizes via condensation of gaseous precursors and heterogeneous reactions. Under certain meteorological conditions, iodine-assisted particle formation can increase cloud condensation nuclei concentrations by 20%-100%.
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http://dx.doi.org/10.1021/acs.est.3c09103 | DOI Listing |
Phys Rev Lett
August 2025
National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing, 100101, Peoples Republic of China.
The Dark Energy Spectroscopic Instrument (DESI) is a massively parallel spectroscopic survey on the Mayall telescope at Kitt Peak, which has released measurements of baryon acoustic oscillations determined from over 14 million extragalactic targets. We combine DESI Data Release 2 with CMB datasets to search for evidence of matter conversion to dark energy (DE), focusing on a scenario mediated by stellar collapse to cosmologically coupled black holes (CCBHs). In this physical model, which has the same number of free parameters as ΛCDM, DE production is determined by the cosmic star formation rate density (SFRD), allowing for distinct early- and late-time cosmologies.
View Article and Find Full Text PDFSci Adv
September 2025
Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA.
Understanding how cells control their biophysical properties during development remains a fundamental challenge. While macromolecular crowding affects multiple cellular processes in single cells, its regulation in living animals remains poorly understood. Using genetically encoded multimeric nanoparticles for in vivo rheology, we found that tissues maintain mesoscale properties that differ from those observed across diverse systems, including bacteria, yeast species, and cultured mammalian cells.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
In eukaryotic systems, three major types of cell junctions have been well characterized. While bacterial adhesion mechanisms also exhibit remarkable diversity, the molecular processes that regulate the dynamic modulation of binding strength between elongated bacterial cells and host cells remain poorly understood. () utilizes the surface adhesin CbpF to interact with the highly expressed host receptors CEACAM1 and CEACAM5 on cancer cells to facilitate tumor colonization.
View Article and Find Full Text PDFInt J Nanomedicine
September 2025
Department of Pharmaceutics and Pharmaceutical Technology, Universitas Padjadjaran, Sumedang, West Java, 45363, Indonesia.
Background: Candidiasis, predominantly caused by , poses a significant global health challenge, especially in tropical regions. Nystatin is a potent antifungal agent that is hindered by its low solubility and permeability, limiting its clinical efficacy.
Methods: This study aimed to investigate the potential of a layer-by-layer (LBL) coating system, employing chitosan and alginate, to improve the stability, entrapment efficiency (%EE), and antifungal efficacy of nystatin-loaded liposomes against Candida albicans.
Int J Nanomedicine
September 2025
The First Hospital of Hunan University of Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, People's Republic of China.
Ulcerative colitis (UC) is a chronic inflammatory bowel disease, the incidence of which continues to rise globally, and existing therapeutic options are limited by low drug bioavailability and systemic side effects. In this study, we systematically investigated the challenges of the special gastrointestinal environment of UC patients for oral drug delivery, such as extreme pH, degradation by digestive enzymes, metabolism of intestinal flora and obstruction of the intestinal mucosal barrier, and summarized the potential of plant-derived Exosome-like Nanovesicles (PELNs) as a novel delivery system. PELNs are produced by plant cells and mainly consist of proteins, RNA, lipids and plant active molecules.
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