Objectives: To evaluate the effect of different ratios of Bis-EMA/Bis-GMA resin mixtures on the inherent viscosity and curing-related properties: including degree of cure (DC%), shrinkage strain, Knoop micro-hardness (KH) and flexural strength of resin-impregnated fiber-bundles.
Methods: Bis-EMA/Bis-GMA monomers were mixed (by weight) in the following ratios: M1 = 30 %/70 %, M2 = 50 %/50 %, M3 = 70 %/30 %, and M4 = 100 %/0 %. Standard measurements were made of refractive index, viscosity, degree of conversion, shrinkage strain and Knoop hardness (KHN). For 60 % glass fiber-bundles impregnated with 40 % resin, three-point bending test for flexural strength and shrinkage strain were measured. Data were analyzed by One-way ANOVA and Bonferroni post-hoc tests (α = 0.05).
Results: For resin mixtures, increasing Bis-EMA proportion decreased refractive index (p < 0.05), and viscosity (p < 0.05), and increased monomer conversion (DC%), shrinkage strain and KHN (p < 0.05). DC% increased after 1 h for all resin mixtures. The shrinkage strain and flexural strength of resin-impregnated fiber-bundles reduced with increased Bis-EMA.
Significance: Monomeric mixtures with highest amounts of Bis-EMA showed enhancement in several clinically-relevant properties and polymerization of respective resin-impregnated glass fibers. This makes them potential candidates for impregnating glass fibers in fiber-reinforced restorations.
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http://dx.doi.org/10.1016/j.dental.2024.07.001 | DOI Listing |
Sci Rep
January 2025
The Fourth Engineering Co., LTD, China Railway Fourth Bureau, Hefei, 230012, People's Republic of China.
Research investigating the complex mechanical properties and energy evolution mechanisms of frozen calcareous clay under the influence of multiple factors is crucial for optimizing the artificial ground freezing method in shaft sinking, thereby enhancing construction quality and safety. In this study, a four-factor, four-level orthogonal test was devised, taking into account temperature, confining pressure, dry density, and water content. The complex nonlinear curvilinear relationship between deviatoric stress, volume strain, and axial strain of frozen calcareous clay under different interaction levels was analyzed.
View Article and Find Full Text PDFDev Comp Immunol
January 2025
Key Laboratory of Marine Genetics and Breeding, Ministry of Education/ Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Qingdao, 266003, Shandong, China. Electronic address:
Antimicrobial peptides (AMPs) are small, potent molecules that serve as a crucial first line of defense across a wide range of organisms, including fish. In this study, we investigated the antimicrobial properties of a novel peptide, spanning residues 52 to 80 of the full-length histone H2A protein, comprising a total of 29 amino acids. This peptide, designated as Histone H2A-29 (TroH2A-29), was derived from the golden pompano (Trachinotus ovatus) and evaluated for its activity against both Gram-positive bacteria, Lactococcus garvieae and Staphylococcus epidermidis, and Gram-negative bacteria, Vibrio alginolyticus and Vibrio harveyi.
View Article and Find Full Text PDFSensors (Basel)
January 2025
China Railway Seventh Group Co., Ltd., Zhengzhou 450016, China.
This paper investigates the use of the BOTDA (Brillouin Optical Time-Domain Analysis) technology to monitor a large-scale bored pile wall in the field. Distributed fiber optic sensors (DFOSs) were deployed to measure internal temperature and strain changes during cement grouting, hardening, and excavation-induced deformation of a secant pile wall. The study details the geological conditions and DFOS installation process.
View Article and Find Full Text PDFPlants (Basel)
December 2024
National-Local Joint Engineering Laboratory of Citrus Breeding, Cultivation/Horticulture Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China.
The 'Cuimi' kumquat is a unique citrus cultivar known for its thin, crisp pulp and sweet, aromatic flavor. In addition to its use in fresh consumption and processing, this variety exhibits certain medicinal properties. This study aims to investigate the genetic diversity of the Huanglongbing (HLB) bacterium across different tissues of the 'Cuimi' kumquat, offering a theoretical basis for understanding the HLB epidemic in Dechang County, Sichuan.
View Article and Find Full Text PDFScience
January 2025
Department of Geoscience, University of Wisconsin-Madison, Madison, WI, USA.
Accurately modeling the deformation of temperate glacier ice, which is at its pressure-melting temperature and contains liquid water at grain boundaries, is essential for predicting ice sheet discharge to the ocean and associated sea-level rise. Central to such modeling is Glen's flow law, in which strain rate depends on stress raised to a power of = 3 to 4. In sharp contrast to this nonlinearity, we found by conducting large-scale, shear-deformation experiments that temperate ice is linear-viscous ( 1.
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