Materials Literature
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We report on photoluminescent properties of ZnO/Zn 0.8 Mg 0.2 O nanorod single-quantum-well structures (SQWs). Catalyst-free metalorganic vapor-phase epitaxy (MOVPE) was employed for precise controls of well widths and compositions of the nanorod SQWs. Both time-integrated and time-resolved photoluminescence (PL) spec…
A systematic sequential procedure is implemented to find local minimum conformers corresponding to the lowest generation (G0), −NH 2 - and −OH-terminated, poly(amidoamine) (PAMAM) dendrimers, and their IR vibrational spectra using ab initio (Hartree−Fock and density functional theory) techniques. It is found that the…
In this study, we investigated the molecular events involved in estrogen-induced angiogenesis. Treatment of the human endometrial adenocarcinoma cells, HEC-1A, with estrogen up-regulated mRNA expression and protein synthesis of various angiogenic factors such as tumor necrosis factor-alpha, interleukin-1, basic fibrob…
A structural and thermodynamical characterization of complexation of poly(amidoamine) dendrimers with metal ions, metal atoms, and copper hydrates is carried out using ab initio (Hartree−Fock and density functional theory) techniques. Three binding sites (core, amide, and amine) are identified and the binding energies…
An investigation has been carried out into gluconate dehydratase from the hyperthermophilic Archaeon Sulfolobus solfataricus. The enzyme has been purified from cell extracts of the organism and found to be responsible for both gluconate and galactonate dehydratase activities. It was shown to be a 45 kDa monomer with a…
To understand, at a molecular scale, the effect of water on the structure of the amorphous region of polyamide 6,6 (PA6,6), atomistic molecular dynamics simulations have been carried out. Our results concerning the very local water organization relative to PA moieties agree qualitatively with a two-step sorption model…
A phylogenetic analysis of the genes encoding enzymes in the pentose phosphate pathway (PPP), the ribulose monophosphate (RuMP) pathway, and the chorismate pathway of aromatic amino acid biosynthesis, employing data from 13 complete archaeal genomes, provides a potential explanation for the enigmatic phylogenetic patt…
We report here on the use of peptide-amphiphile (PA) nanofibers displaying the S(P)RGD peptide sequence on their exterior as templates for the mineralization of cadmium sulfide (CdS). At low Cd:PA ratios, the nanofibers nucleate and organize quantum-confined 3-5 nm CdS nanocrystals into linear arrays. Tubular structur…
A predictive model of the effect of crystal agglomeration on particle form and size distribution requires the quantification of various process parameters that depend on the microscopic properties of specific crystal faces and their interaction with the solvent. In this article, we discuss the various stages in the ag…
The magnetic ordering of the normal spinel ferrimagnet NiCr 2 O 4 below T C = 74 K was reinvestigated by neutron scattering and magnetization measurements on a powder specimen. We found another magnetic transition at T S = 31 K besides T C in both experiments. The ordering of a ferrimagnetic (longitudinal) component a…
Very few standards exist for fitting products to people. Footwear is a noteworthy example. This study is an attempt to evaluate the quality of footwear fit using two-dimensional foot outlines. Twenty Hong Kong Chinese students participated in an experiment that involved three pairs of dress shoes and one pair of athle…
Type II fatty acid biosynthesis systems are essential for membrane formation in bacteria, making the constituent proteins of this pathway attractive targets for antibacterial drug discovery. The third step in the elongation cycle of the type II fatty acid biosynthesis is catalyzed by beta-hydroxyacyl-(acyl carrier pro…
The kinetics of crystalline ice nucleation and growth in nonporous, molecular beam deposited amorphous solid water (ASW) films are investigated at temperatures near 140 K. We implement an experimental methodology and corresponding model of crystallization kinetics to decouple growth from nucleation and quantify the te…
We have examined the performance of the analytic Hartree-Fock-Slater (HFS) method for various alpha (Slater's exchange parameter) values and empiricaly determined the optimal alpha value by minimizing the mean absolute error (MAE) in atomization energies of the G2 set of molecules. At the optimal alpha the HFS method'…
The poly(amidoamine) dendrimers having terminal isobutyramide (IBAM) groups were prepared by the reaction of isobutyric acid and the amine-terminated poly(amidoamine) dendrimers with generations (G) of 2 to 5 by using a condensing agent, 1,3-dicyclohexylcarbodiimide. 1H and 13C NMR revealed that an IBAM group was atta…
About thirty high-field magnetoresistance Stereographic Maps have been measured for metals between Fifties and Seventies but no way was known till now to compare these complex experimental data with first-principles computations. We present here the method we developed to generate Stereographic Maps directly from a me…
Solid mercury in the rhombohedral structure is unbound within the self-consistent field (Hartree-Fock) approximation. The metallic binding is entirely due to electronic correlations. We determine the cohesive energy of solid mercury within an ab-initio many-body expansion for the correlation part. Electronic correlati…
A many-body expansion for mercury clusters of the form E = \sum_{i
Annealing can increase the Curie temperature and net magnetization in uncapped (Ga,Mn)As films, effects that are suppressed when the films are capped with GaAs. Previous polarized neutron reflectometry (PNR) studies of uncapped (Ga,Mn)As revealed a pronounced magnetization gradient that was reduced after annealing. We…
The nature of the bonding in Li$_3$AlH$_6$ has been re-examined with additional analyses using density-functional calculations. From partial density of states, charge density distribution, charge transfer, electron localization function, crystal orbital Hamilton population and Mulliken population analyses it is conclu…