A new process of mechanically initiated formation of chitosan physical hydrogels in aqueous solution, without a cross-linking agent, was studied. Physical hydrogel is formed by mechanical activation of solutions of chitosan with a low deacetylation degree (58%) in situ in a rotor-stator device for 10 s. The formation of 3D gel structure has been proven by rotational viscometry and dynamic rheometry methods. Gelation is caused by the action of high shear stresses initiating the formation of hydrophobic associates from residual chitinous blocks. In comparison with the films from untreated chitosan, the films obtained by drying hydrogel have a lower degree of crystallinity and a higher sorption capacity towards water vapor and Cu ions, as well as the ability to retain up to 5000% of water during re-swelling without destruction.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.07.164 | DOI Listing |
BMJ Case Rep
January 2025
Dermatology, Ninewells Hospital and Medical School Department of Dermatology, Dundee, UK.
A man in his early 40s presented with extensive skin lesions in the groin and genital regions. The lesions were erythematous and maculopapular but evolved into vesicles and pustules with surrounding cellulitis. He stated that he grips livestock between his legs for sheep shearing.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; Jiaxing Institute of Future Food, Jiaxing 314050, China. Electronic address:
Oleogels with solid-like properties can serve as substitutes for fats, thereby avoiding the consumption of high levels of saturated fatty acids. In this study, we developed a protein-polysaccharide composite network oleogel using whey protein isolate (WPI) and sodium alginate (SA) through an emulsion-templated method. Analysis with Fourier Transform Infrared (FTIR) spectroscopy confirmed the presence of hydrogen bonds and van der Waals forces between WPI and SA, which bolstered the oleogel's structure.
View Article and Find Full Text PDFMater Today Bio
February 2025
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, PR China.
Natural teeth fulfill functional demands by their heterogeneity. The composition and hydroxyapatite (HAp) nanostructured orientation of enamel differ from those of dentin. However, mimicking analogous materials still exhibit a significant challenge.
View Article and Find Full Text PDFInt J Dent
January 2025
Department of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
This research aimed to assess the shear bond strength (SBS) of metal brackets bonded to composite veneers using different surface preparations. One-hundred composite disks were divided into 10 different groups whereby each group combines a surface preparation (roughening or no roughening), etching agent (37% phosphoric or 9.5% hydrofluoric acid), adhesive protocol (self-etch or total-etch), and bonding agent (with or without G-Premio Bond).
View Article and Find Full Text PDFACS Omega
January 2025
School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China.
The distribution of high-viscosity microfilms in designated regions is crucial for the performance and durability of MEMS devices. This paper presents a novel method for controllable film formation in the milli/micron region by blade coating. A microfilm can be formed without viscosity limitation, and the formation process can be monitored only via a one-dimensional force sensor.
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