{"paper":{"title":"Effects of Divalent Cations on Diffusion Dynamics of Biological Water Confined between Lipid Membranes","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Calcium ions steadily increase the diffusion rate of water confined between lipid membranes, while magnesium ions produce a non-monotonic effect.","cross_cats":[],"primary_cat":"cond-mat.soft","authors_text":"Jaeyoung Sung, Ji-Hyun Kim, Jinwon Park, Minhaeng Cho, Minho Lee","submitted_at":"2026-03-20T07:48:59Z","abstract_excerpt":"Biological water is an ionic solution containing both monovalent and divalent ions. However, the effects of divalent ions on the dynamics of biological water remain largely unknown. Here, we investigate how the transport dynamics of water molecules nanoconfined between lipid membranes depends on the concentration of calcium (Ca2+) and magnesium (Mg2+) ions by using molecular dynamics simulations and the generalized transport equation for biological water. We find that the diffusion coefficient of biological water monotonically increases with Ca2+ ion concentration but exhibits a largely opposi"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We find that the diffusion coefficient of biological water monotonically increases with Ca2+ ion concentration but exhibits a largely opposite, non-monotonic dependence on Mg2+ concentration. These contrasting behaviors originate from the different hydration radii of these divalent ions and their distinct effects on the interfacial structure and dynamics of biological water.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The molecular dynamics force fields and the generalized transport equation faithfully reproduce the real interfacial structure, ion hydration, and diffusion fluctuations without significant artifacts from finite system size or parameter choices.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Simulations find calcium ions monotonically raise the diffusion coefficient of nanoconfined biological water while magnesium ions yield non-monotonic dependence due to differing hydration radii and interfacial effects.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Calcium ions steadily increase the diffusion rate of water confined between lipid membranes, while magnesium ions produce a non-monotonic effect.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"503b326819987b6576e8709db9a994c2591f08fccf5ca262f98d4c3b88fc6fca"},"source":{"id":"2603.19719","kind":"arxiv","version":3},"verdict":{"id":"d19e5ba3-066d-439c-9666-457398a06908","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T07:40:45.308008Z","strongest_claim":"We find that the diffusion coefficient of biological water monotonically increases with Ca2+ ion concentration but exhibits a largely opposite, non-monotonic dependence on Mg2+ concentration. These contrasting behaviors originate from the different hydration radii of these divalent ions and their distinct effects on the interfacial structure and dynamics of biological water.","one_line_summary":"Simulations find calcium ions monotonically raise the diffusion coefficient of nanoconfined biological water while magnesium ions yield non-monotonic dependence due to differing hydration radii and interfacial effects.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The molecular dynamics force fields and the generalized transport equation faithfully reproduce the real interfacial structure, ion hydration, and diffusion fluctuations without significant artifacts from finite system size or parameter choices.","pith_extraction_headline":"Calcium ions steadily increase the diffusion rate of water confined between lipid membranes, while magnesium ions produce a non-monotonic effect."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2603.19719/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"7e9e043c54c71c9ea75f76278635e0517a6896e73303e0f74127310836cfc818"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}