This article provides historical background on the development of resin-based dental restorative materials. With an understanding of the evolution of these materials, clinicians can better appreciate both the complexity of and similarities among the wide variety of resins and polymerization techniques available today. Common problems associated with the use of resin-based materials are explained, and more advanced resin-based systems currently under development are briefly reviewed.
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http://dx.doi.org/10.1067/mpr.2002.123400 | DOI Listing |
J Hazard Mater
January 2025
Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China. Electronic address:
Microplastics (MPs, 1 µm-5 mm) and nanoplastics (NPs, < 1 µm), collectively termed micro(nano)plastics (MNPs), are pervasive airborne pollutants with significant ecological risks. Birds, recognized as bioindicators, are particularly vulnerable to MNP exposure, yet the extent and risks of MNP pollution in bird lungs remain largely unexplored. This study assessed MP exposure in bird lungs of 51 species and NP exposure in the lungs of five representative species using laser direct infrared (LDIR) and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) techniques, respectively.
View Article and Find Full Text PDFChemosphere
January 2025
Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hanoi, 10000, Viet Nam. Electronic address:
Chlorinated paraffins (CPs) are chemical additives mostly composed of polychlorinated alkanes (PCAs) which may impact on the environment and human health; however, little is known about their presence in Southeast Asia. To fill this knowledge gap, we assessed 74 PCA homolog groups commonly referred to as short-chain (SCCPs: PCAs-C), medium-chain (MCCPs: PCAs-C), and long-chain CPs (LCCPs: PCAs-C) in technical CP mixtures (n = 4) and polymer samples (n = 49), including recycled plastics, collected in Vietnam in 2023. The contents of measured PCA homolog groups in technical CP mixtures were 86,000-930,000 mg/kg for PCAs-C; 85,000-990,000 mg/kg for PCAs-C; and 23,000-180,000 mg/kg for PCAs-C.
View Article and Find Full Text PDFMolecules
December 2024
Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, I. Lučića 5, 10000 Zagreb, Croatia.
In this study, poly(vinyl-alcohol) (PVA)/chitosan (CS) polymer blend films with different amounts of CS (0, 5, 20 and 35 wt. %) crosslinked by glutaraldehyde (GA) were prepared. The structure and properties of the prepared polymer films were studied by means of dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and the time-lag permeation technique.
View Article and Find Full Text PDFMethodsX
December 2024
University of Copenhagen, Department of Plant and Environmental Sciences, Thorvaldsensvej, 40, 1821, Frederiksberg, Denmark.
Iron oxide-impregnated filter papers (FeO) facilitate the study of soil phosphorus (P) desorption, availability and dynamics. However, many studies use homogenized and saturated shaking FeO soil systems, hindering opportunities to resolve environmentally relevant experimental objectives. This study created and evaluated a static microcosm to study soil P dynamics with FeO papers.
View Article and Find Full Text PDFMacromol Rapid Commun
November 2024
Dipartimento di Chimica e Biologia "Adolfo Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, Fisciano, SA, 84084, Italy.
The advancement of stereoregular polymerization techniques for linear 1,3-dienes has enabled the production of polymers with precise stereocontrol, influencing their physical and chemical properties significantly. While 1,3-butadiene and isoprene yield diverse stereoregular polymers, cyclic dienes have received less attention due to catalyst challenges and limited application in the rubber industry. However, the growing interest in bio-based monomers, particularly those derived from terpenes and terpenoids, has revitalized interest in cyclic monomers with conjugated double bonds.
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