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In this study, water-based precursor solutions with citric acid as the chelating agent were prepared, and the effect of the pH of the precursor solutions on the morphology and microstructure of the Li1.3Al0.3Ti1.7(PO4)3 (LATP) coating layer was investigated. A clear precursor solution was prepared and its colour changed depending on the pH of the solution, suggesting that citric acid effectively formed chelate complexes composed of Li, Al, Ti and P ions. The scanning electron microscopy and energy-dispersive X-ray spectroscopy mapping analyses showed that a low pH resulted in a homogeneous LATP coating layer with a fine particle size and less dense morphology. When the pH value was increased, dense and enhanced surface coverage was obtained, whereas an inhomogeneous atomic distribution was confirmed in the LATP coating. The LATP-coated LiCoO2 (LCO) cathode exhibited enhanced specific capacity retention compared to that of the pristine LCO cathode. [ABSTRACT FROM AUTHOR]

Computations for hydrogen-bonding structures and energies, utilizing the pseudospectral local MP2 methodology and a high-quality triple zeta basis set for a large group of amino acid side chain analogues were performed. Both neutral and charged amino acid analogues were investigated and interactions between donors and the pi electron acceptor moiety in a benzene ring were analyzed. Findings revealed that donors and acceptors can be classified either as strong or weak, with the weak species severely damping changes in hydrogen-bonding strength as the partner donor or acceptor is changed.

The influence of controlled phase shift between very high frequency (100 MHz) voltages applied to the powered electrodes on the plasma uniformity and etch rate was studied in a capacitive triode-type reactor. Radial profiles of plasma optical emission were measured as a function of the phase shift in process (C4F8/O2/Ar) plasma with the low frequency bias power both turned off and on. Radial profiles of KrF photoresist etch rate over a 300 mm wafer were obtained in the same conditions (with the bias power turned on). Besides, plasma density at the wafer center and edge was measured versus the phase shift in pure Ar plasma. It occurred that all measured characteristics strongly depend on the phase shift and correlate with each other. It has been shown that the phase-shift control can considerably improve both the plasma and etch-rate uniformity in very high-frequency capacitive reactors. [ABSTRACT FROM AUTHOR]

Bisphenol A glycidyl methacrylate (bis-GMA), which is released into the oral environment by dental composites through incomplete polymerization, hydrolysis, and mechanical degradation, can significantly influence oral ecology around resin-based materials. The purpose of this study was to investigate how bis-GMA changes the virulence properties of Streptococcus mutans, a major cariogenic bacterium in humans. The results show that bis-GMA not only inhibited the planktonic growth of cells in medium containing glucose, fructose, or mannose, but also reduced the viability of S. mutans. However, the presence of bis-GMA increased sugar transport and intracellular polysaccharide accumulation in S. mutans, thereby increasing the potential of cell persistence. In addition, bis-GMA could enhance S. mutans's adhesion to hard surfaces and glucan synthesis, which could contribute to biofilm formation. Although free bis-GMA made cells vulnerable to acidic stress, it also provided increased resistance to hydrogen peroxide, which might confer an advantage in competition with other oral microorganisms during the early stage of biofilm development. Interestingly, the presence of bis-GMA did not change the ability of S. mutans to interact with saliva. The results suggest that leachable bis-GMA could contribute to biofilm-related secondary dental caries at the marginal interface between resin-based materials and teeth by altering the virulent properties of S. mutans, although bis-GMA reduced the planktonic growth and viability of S. mutans. [ABSTRACT FROM AUTHOR]

A number of ab initio approaches have been used to determine the equilibrium structures, energies, and vibrational frequencies of N2H2 in the ground state and in the excited singlet and triplet n→π* states. The methods included restricted Hartree–Fock (RHF) and unrestricted Hartree–Fock (UHF), multiconfiguration self-consistent field (MCSCF), single-reference configuration interaction (SRCI) and multireference configuration interaction (MRCI) including all single and double excitations from the reference configurations, and second-order Mo\ller–Plesset perturbation theory (MP2) using RHF and UHF orbitals for ground and excited states, respectively. Unlike the singlet excited state, for which broken-symmetry solutions were found at the RHF level, no symmetry breaking was encountered for the triplet state. The ground-state MCSCF and MP2 structures of N2H2, which have C2h (trans-planar) symmetry, are in good agreement with the experimental structure. The excited states are predicted to have nonplanar C2 structures with dihedral angles ranging from 96° to 106° for the triplet state and from 105° to 121° for the singlet state. Except for the SRCI singlet adiabatic excitation energy, the effect of configuration interaction is to increase the vertical and adiabatic excitation energies of both excited states relative to the RHF values in single-reference calculations, and to decrease these excitation energies relative to MCSCF values in multireference calculations, bringing the single-reference and multireference CI values into better agreement with each other. The MRCI vertical excitation energies are 2.6 eV for the triplet and 3.6 eV for the singlet, while the corresponding 0–0 transition energies are 1.9 and 2.9 eV, respectively. [ABSTRACT FROM AUTHOR]