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Hydrodynamic properties of a series of ionic polysaccharides with different charge density but the same molecular weight have been evaluated in salt-free aqueous solution and aqueous/organic solvent mixtures by means of capillary viscometry. The polyelectrolytes investigated contain quaternary ammonium salt groups, N-ethyl-N,N-dimethyl-2-hydroxypropylammonium chloride, attached to a dextran backbone. The experimental viscometric data have been plotted in terms of the Wolf method. The results show that the experimental data fit well with this model and allow the calculation of intrinsic viscosities and other hydrodynamic parameters, which provide new information about the dependence of the polyion conformation on its polyion charge density as well as on solvent composition.
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http://dx.doi.org/10.1021/jp900690f | DOI Listing |
Proc Natl Acad Sci U S A
September 2025
The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa 56025, Italy.
Aquatic microorganisms typically inhabit a heterogeneous resource landscape, composed of localized and transient patches. To effectively exploit these resources, they have evolved a wide range of feeding strategies that combine chemotactic motility with active feeding flows. However, there is a notable lack of experimental studies that examine how these active flows shape resource fields to optimize feeding.
View Article and Find Full Text PDFThe Ordos Basin's Hangjinqi Shiligahan west zone Xiashihezi Formation 1 Member gas reservoir exhibits significant exploration and development potential. However, its sedimentation and reservoir characteristics are poorly understood. To address this, geological, seismic, macroscopic, and microscopic methods are combined.
View Article and Find Full Text PDFFood Chem
September 2025
Postgraduate Program in Chemical Engineering, Federal University of Paraiba, João Pessoa, PB, Brazil.
This study evaluated the modification of corn starch using low-intensity pulsed electric field (PEF: 10 kV) combined with sodium salts (NaCl, NaCO₃, NaH₂PO₄) to investigate how pH and increased electrical conductivity affect starch structure. The study examined how salt pH and increased conductivity from electronegativity differences enhance polymer structural changes. NaCO₃ reduced amylose and long amylopectin chains (DP ≥ 37) by 18 %, confirmed by hydrodynamic radius (Rh) reductions for amylose (3.
View Article and Find Full Text PDFJ Hazard Mater
September 2025
School of Environmental Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 611756, China; Sichuan Engineering Research Center for Pollution Control in Rail Transit Engineering, Chengdu, Sichuan 611756, China; Sichuan International Science and Technology Cooperation base for Int
In alpine meadow regions, macropore flow is a critical but inadequately understood pathway for antibiotic transport. The complex relationship between macropore structure, flow dynamics, and solute properties presents a significant research gap. Methodological limitations hinder the accurate characterization of solute migration mechanisms due to complex macropore structures.
View Article and Find Full Text PDFJ Orthop Translat
November 2025
Medical 3D Printing Center, Orthopedic Institute, Department of Orthopedic Surgery, The First Affiliated Hospital, School of Basic Medical Sciences, Interdisciplinary Innovation Center for Nanomedicine, MOE Key Laboratory of Geriatric Diseases and Immunology, Suzhou Medical College, Soochow Universi
Background: Intervertebral disc (IVD) herniation is a major cause of low back pain and disability, with microdiscectomy being the standard surgical treatment. However, microdiscectomy fails to address annulus fibrosus (AF) defects, increasing the risk of recurrent herniation. Current therapeutic strategies for this condition remain limited in efficacy.
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