The review considers methods of manufacturing photopolymerizable compositions for bone tissue repair, as well as polymers and photoinitiators used for this purpose. Their physical and biological properties are described. Examples of light-curing compositions used in biomedicine and tissue engineering are given.
View Article and Find Full Text PDFThe Aim Of The Study: Was to elaborate and assess biocompatible compositions based on oligocarbonate methacrylate filled with hydroxyapatite.
Materials And Methods: The manufacturing methods of the compositions are considered, and their polymerization ability, strength and elastic properties are evaluated.
Results: The highest values of hardness and elasticity were found in the composition containing 0.
Proc Natl Acad Sci U S A
December 2024
Estimating the cost to society from a ton of CO-termed the social cost of carbon (SCC)-requires connecting a model of the climate system with a representation of the economic and social effects of changes in climate, and the aggregation of diverse, uncertain impacts across both time and space. A growing literature has examined the effect of fundamental structural elements of the models supporting SCC calculations. This work has accumulated in a piecemeal fashion, leaving their relative importance unclear.
View Article and Find Full Text PDFFor the first time, widespread aqueous biphasic polymer-salt extraction system was applied for selective separation of Pd(II) and Pt(IV) from chloride technological solutions by countercurrent chromatography using a rotating coiled column (an analog of centrifugal extractor). The principle novelty of the proposed approach is the possibility of multistage extraction process and the needlessness to add any specific reagents for targeted metal binding. The results showed that the use of poly(ethylene glycol)-1500 (PEG-1500) as a stationary phase allows 96-100% of both Pd(II) and Pt(IV) to be recovered from chloride solutions containing copper and nickel.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2020
Massive wildlife losses over the past 50 y have brought new urgency to identifying both the drivers of population decline and potential solutions. We provide large-scale evidence that air pollution, specifically ozone, is associated with declines in bird abundance in the United States. We show that an air pollution regulation limiting ozone precursors emissions has delivered substantial benefits to bird conservation.
View Article and Find Full Text PDFHundreds of millions of visitors travel to U.S. national parks every year to visit America's iconic landscapes.
View Article and Find Full Text PDFA simple, rapid, and sensitive method for isolation and detection of macrolide endectocides (moxidectin, doramectin, selamectin, ivermectin, and eprinomectin) in animal sera and liver is described. Fortified sera or homogenized liver samples were treated with sodium chloride followed by organic solvent extraction. No additional steps were required prior to analysis.
View Article and Find Full Text PDFArch Biochem Biophys
August 2001
The redox-inactive thioester analog 3-thia-octanoyl-CoA blocks transfer of a hydride equivalent to the flavin prosthetic group of the medium-chain acyl-CoA dehydrogenase with the accumulation of a stable enolate intermediate not encountered with normal substrates. Substitution of the normal flavin with 5-deaza-FAD would thus be expected to lead to enolate formation with both normal and 3-thia-substrate analogs, because reduction of the 5-deaza-enzyme is thermodynamically highly unfavorable. However, spectrophotometric titrations show that neither ligand forms significant enolate species with the 5-deaza-FAD enzyme.
View Article and Find Full Text PDF4-OH-Cinnamoyl-CoA has been synthesized as a probe of the active site in the medium chain acyl-CoA dehydrogenase. The protonated form of the free ligand (lambda(max) = 336 nm) yields the corresponding phenolate (lambda(max) = 388 nm) with a pK of 8.9.
View Article and Find Full Text PDFOxidation of thioester substrates in the medium-chain acyl-CoA dehydrogenase involves alpha-proton abstraction by the catalytic base, Glu376, with transfer of a beta-hydride equivalent to the flavin prosthetic group. Polarization of bound acyl-CoA derivatives by the recombinant human liver enzyme has been studied with 4-thia-trans-2-enoyl-CoA analogues. Polarization is maximal at low pH, with an apparent pK of 9.
View Article and Find Full Text PDFPediatr Akus Ginekol
November 1978
Pediatr Akus Ginekol
August 1976