In the current study, we present methods of sodium hyaluronate, also denoted as hyaluronan (HA), nanofiber fabrication using a direct-current (DC) electric field. HA was spun in combination with poly(vinyl alcohol) (PVA) and polyethylene oxide (PEO) and as a pure polymer. Nonaggressive solvents were used due to the possible use of the fibers in life sciences. The influences of polymer concentration, average molecular weight (), viscosity, and solution surface tension were analyzed. HA and PVA were fluorescent-labeled in order to examine the electrospun structures using fluorescence confocal microscopy. In this study, two intermediate solvent mixtures that facilitate HA electrospinning were found. In the case of polymer co-electrospinning, the effect of the surfactant content on the HA/PVA electrospinning process, and the effect of HA on HA/PEO nanofiber morphology, were examined, respectively.
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http://dx.doi.org/10.3390/polym11091517 | DOI Listing |
J Chem Phys
January 2025
Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Host-guest binding plays a crucial role in the functionality of various systems, and its efficiency is often quantified using the binding free energy, which represents the free-energy difference between the bound and dissociated states. Here, we propose a methodology to compute the binding free energy based on the energy representation (ER) theory of solution, which enables us to evaluate the free-energy difference between the systems of interest with the molecular dynamics (MD) simulations. Unlike the other free-energy methods, such as the Bennett acceptance ratio (BAR), the ER theory does not require the MD simulations for hypothetical intermediate states connecting the systems of interest, leading to reduced computational costs.
View Article and Find Full Text PDFBMC Microbiol
January 2025
Microbial Chemistry Department, Biotechnology Research Institute, National Research Center, Dokki, Giza, Egypt.
The red pigment was recovered from the S. phaeolivaceus GH27 isolate, which was molecularly identified using 16S rRNA gene sequencing and submitted to GenBank as OQ145635.1.
View Article and Find Full Text PDFHerein, we present a sustainable and atom-economical approach for the synthesis of quinazolinones via acceptorless dehydrogenative coupling (ADC) using earth-abundant Co-salt, (CoCl2) as the catalyst under neat condition. This method is distinguished by its green credentials, like, solvent-free, microwave-assisted heating, cost-effective, use of renewable alcohols, and generating only H2 and water as byproducts. Remarkably, this protocol achieves quinazolinone synthesis without the need for external ligands, oxidants, or additional additives.
View Article and Find Full Text PDFBMC Cancer
January 2025
Centre for Medical Education, Queen's University Belfast, Belfast City Hospital, Lisburn Road, Belfast, UK.
Background: Myelofibrosis (MF) is a clonal haematopoietic disease, with median overall survival for patients with primary MF only 6.5 years. The most frequent gene mutation found in patients is JAK2, causing constitutive activation of the kinase and activation of downstream signalling.
View Article and Find Full Text PDFChemistry
January 2025
SIOC: Shanghai Institute of Organic Chemistry, Key Laboratory of Organofluorine Chemsitry, 345 Lingling Road, 200032, Shanghai, CHINA.
A solvent dependent C(sp3)-CF3 bond-forming reductive elimination from neutral four-coordinate Cu(III) complexes [(L)Cu(CF3)2(CH2CO2tBu)] (L = pyridine or its derivatives) is described. Reactions in less polar solvent ClCH2CH2Cl proceed via a concerted bond breaking/bond forming process along with the reorientation of the ligand, while reaction in polar solvent DMF occurs via a rate limiting ligand-dissociation, followed by C(sp3)-CF3 reductive elimination from the resulting three-coordinate intermediate. These mechanistic proposals are supported by kinetic studies that included ligand and temperature effects, as well as DFT calculations.
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