Uniformly sized, polymer-based packing materials affording excellent chromatographic performance in semimicro HPLC were prepared from mixtures of alkyl methacrylate and glycerol dimethacrylate by a copolymerization technique using a multistep swelling and polymerization method. A column efficiency of up to 13000 plates was obtained for a 2-mm-i.d. x 150-mm column with beads prepared from a 1:1 (v:v) mixture of an alkyl methacrylate and glycerol dimethacrylate. The packing materials exhibit a considerable improvement in column efficiency, as demonstrated on the separation of polyaromatic hydrocarbons (PAHs) having a relatively long retention time, which thus far has been a serious problem of polymer-based packing materials. Detailed studies suggested a rather limited optimum pore size, and its distribution was depicted to get the excellent column efficiency on polymer-based packing materials.
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http://dx.doi.org/10.1021/ac0105991 | DOI Listing |
Sci Adv
January 2025
Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
Understanding chromatin organization requires integrating measurements of genome connectivity and physical structure. It is well established that cohesin is essential for TAD and loop connectivity features in Hi-C, but the corresponding change in physical structure has not been studied using electron microscopy. Pairing chromatin scanning transmission electron tomography with multiomic analysis and single-molecule localization microscopy, we study the role of cohesin in regulating the conformationally defined chromatin nanoscopic packing domains.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Center for Electron Microscopy, South China University of Technology, Guangzhou 511436, China.
Adsorption behaviors are typically examined through adsorption isotherms, which measure the average adsorption amount as a function of partial pressure or time. However, this method is incapable of identifying inhomogeneities across the adsorbent, which may occur in the presence of strong intermolecular interactions of the adsorbate. In this study, we visualize the adsorption of molecular iodine (I) in the metal-organic framework material MFM-300(Sc) using high-resolution scanning transmission electron microscopy (STEM).
View Article and Find Full Text PDFACS Nano
January 2025
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
Freestanding networked nanoparticle (NP) films hold substantial potential due to their high surface areas and customizable porosities. However, NPs with high surface energies and heterogeneous sizes or shapes present considerable challenges as they tend to aggregate, compromising their structural integrities. In this study, we report the scalable fabrication of ultrathin, bicontinuous, and densely packed carbon NP films via Pickering emulsion-mediated interfacial assembly.
View Article and Find Full Text PDFJ Anat
January 2025
Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences (ILCaMS) and Human Anatomy Resource Centre (HARC), Education Directorate, University of Liverpool, Liverpool, UK.
The importance of interactions between neighbouring rapidly growing tissues of the head during development is recognised, yet this competition for space remains incompletely understood. The developing structures likely interact through a variety of mechanisms, including directly genetically programmed growth, and are mediated via physiological signalling that can be triggered by structural interactions. In this study, we aimed to investigate a different but related potential mechanism, that of simple mechanical plastic deformation of neighbouring structures of the head in response to soft tissue expansion during human postnatal ontogeny.
View Article and Find Full Text PDFNano Lett
January 2025
School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand.
Understanding metastable structural transitions under beam irradiation is essential for the phase engineering of nanomaterials. However, in situ studies of beam-induced structural transitions remain challenging. This work uses an electron beam in aberration-corrected high-angle annular dark-field scanning transmission electron microscopy to irradiate Au nanocrystals at room temperature.
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