One of the most important purposes in molecular technologies is the preparation of supramolecular structures by self-assembling processes. The aromatic molecules self-associate mainly in π-π stacked structures with an aggregate size distribution determined by the association equilibrium constants. A general expression for the equilibrium constants K(n,m) which govern the self-association of two aggregates with n and m monomers respectively has been obtained. The model predicts also the concentrations of free monomers, the concentrations of n-mers, and the total concentration of aggregates. (1)H NMR experiments have been used to illustrate the applicability of the proposed model in a particular case: π-stacking self-association of ciprofloxacin in solution.
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http://dx.doi.org/10.1021/jp3034215 | DOI Listing |
ACS Omega
January 2025
Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 30050, Taiwan, ROC.
Here, we report the design, synthesis, and comprehensive characterization of the bis-cholesterol supramolecular gelator, which contains photochromic stiff-stilbene as a bridging unit. The -isomer of stiff-stilbene bridged bis-cholesterol (-) was first synthesized with a systematic design, which can be further converted into its -isomer (-) with a high degree of efficiency (ca. 100%) upon exposure to 385 nm UV light.
View Article and Find Full Text PDFNat Commun
January 2025
The Faculty of Data and Decisions Sciences, Technion - Israel Institute of Technology, Haifa, Israel.
Large Language Models (LLMs) have shown success in predicting neural signals associated with narrative processing, but their approach to integrating context over large timescales differs fundamentally from that of the human brain. In this study, we show how the brain, unlike LLMs that process large text windows in parallel, integrates short-term and long-term contextual information through an incremental mechanism. Using fMRI data from 219 participants listening to spoken narratives, we first demonstrate that LLMs predict brain activity effectively only when using short contextual windows of up to a few dozen words.
View Article and Find Full Text PDFNat Commun
January 2025
NMR Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
Aggregation intermediates play a pivotal role in the assembly of amyloid fibrils, which are central to the pathogenesis of neurodegenerative diseases. The structures of filamentous intermediates and mature fibrils are now efficiently determined by single-particle cryo-electron microscopy. By contrast, smaller pre-fibrillar α-Synuclein (αS) oligomers, crucial for initiating amyloidogenesis, remain largely uncharacterized.
View Article and Find Full Text PDFFood Chem
January 2025
Research Center of Grain and Oil Functionalized Processing in Universities of Shaanxi Province, College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling 712100, Shaanxi, PR China. Electronic address:
β-Cyclodextrin (β-CD) enhances functional properties by forming inclusion complexes (ICs). This study employed β-CD to form IC with fatty acid ethyl ester (FAEE) for concentrating α-Linolenic acid ethyl ester (ALAEE) from flaxseed oil FAEE, and investigated the interaction mechanisms between β-CD and ALAEE. Using the single-factor method, optimal inclusion conditions yielded an inclusion rate of 61.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of General Surgery, The First Affiliated Hospital of University of Science and Technology of China, Key Laboratory of Immune Response and Immunotherapy, Center for Advanced Interdisciplinary Science Interdisciplinary Science & Biomedicine of Institute of Health and Medicine, Division of Life Sciences & Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China.
The DNA-sensing protein cGAS plays a pivotal role in the innate immune response and pathogenesis of various diseases. DNA triggers liquid-liquid phase separation (LLPS) and enhances the enzymatic activity of cGAS. However, the regulatory mechanisms of the disordered N terminus remain unclear.
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