Materials Literature
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Monazite-structure orthophosphates, including ${\mathrm{LaPO}}_{4},$ ${\mathrm{PrPO}}_{4},$ ${\mathrm{NdPO}}_{4},$ ${\mathrm{SmPO}}_{4},$ ${\mathrm{EuPO}}_{4},$ ${\mathrm{GdPO}}_{4},$ and natural monazite, and their zircon-structure analogs, including ${\mathrm{ScPO}}_{4},$ ${\mathrm{YPO}}_{4},$ ${\mathrm{TbPO}}_{4},$…
Two-dimensional heteronuclear (1H-15N) nuclear magnetic relaxation studies of dihydrofolate reductase (DHFR) from Escherichia coli have demonstrated that glycine-121 which is 19 A from the catalytic center of the enzyme has large-amplitude backbone motions on the nanosecond time scale [Epstein, D. M., Benkovic, S. J.,…
The distinction between point and line resolution in transmission electron microscopy (TEM) arises because an ability to image sub-0.2 nm fringes is a necessary, but not a sufficient, condition for imaging individual atoms. In scanned tip microscopy, as in TEM, empirical data on instrument response should precede asse…
A novel process to produce a nanochannel comprised of a void in a polymer matrix is reported. The processing involves a selective degradation of one of the bicontinuous microdomain phases of microphase-separated block copolymers to create a continuous, tortuous hole having a diameter of nanometer scale (nanochannel) a…
RATIONALE AND OBJECTIVES: The authors evaluate MS-325, a new albumin-targeted magnetic resonance imaging (MRI) contrast agent, for its pharmacokinetics, biodistribution, and elimination characteristics in multiple animal species. METHODS: Studies were performed in rats, rabbits, and nonhuman primates at intravenous do…
RATIONALE AND OBJECTIVES: The authors developed a new method for delivering contrast agents to tumors and tumor cells. Gadolinium complexes of folate-conjugated dendrimer-chelates increased the longitudinal relaxation rate of tumor cells expressing the high-affinity folate receptor, hFR. The coupling of folate to poly…
High molecular weight poly(butylene succinate- co -ethylene succinate)s, P(BS- co -ES)s, were obtained from succinic acid, 1,4-butanediol, and/or ethylene glycol through a polycondensation process. Enzymatic hydrolysis of hot-pressed copolyester films was carried out by utilizing lipases derived from a wide variety of…
A novel method was developed to prepare shell-cross-linked knedel-like structures (SCK's), which are double-layered polymer nanospheres, in a convenient three-step procedure: (1) polystyrene- b -poly(acrylic acid) ((DP n ) PS = 130, (DP n ) PAA = 120) copolymer was prepared by sequential anionic polymerization of styr…
A method for estimating the microscopic probability rate of phonon-assisted energy transfer between rare-earth $(3+)$ ions in solids was developed based on Dexter's theory for phonon-assisted energy transfer. The proposed method in this paper enables one to calculate the overlap integral from fundamental cross-section…
Our recent kinetic and mechanistic studies of the formation of Bu 4 N + and P 2 W 15 Nb 3 O 62 9 - polyoxoanion-stabilized Ir(0) ∼ 300 nanoclusters led to the elucidation of a new mechanism for nanoclusters synthesized from metal salts under H 2: slow, continuous nucleation, rate constant k 1, then autocatalytic surfa…
The fluorescence spectra of 9-anthrol during the sol−gel−xerogel transitions of 13 systems containing different silicon and aluminum ratios and catalysts have been observed at a constant temperature (300 K) as a function of the sol−gel reaction time. Fluorescence decay curves for typical xerogel samples also have been…
Small-angle x-ray scattering was used to characterize the single-particle scattering factors produced by poly(amidoamine) dendrimers, poly(propleneimine) dendrimers, and polyol hyperbranched polymers in dilute solutions with methanol as solvent. Fits from electron density modeling reveal similar overall densities of t…
Corrosion and passivation of solution-treated (ST), solution-treated and aged (STA), and diffusion-hardened (DH) variants of Ti-13% Nb-13% Zr (Ti-13-13) were examined in a simulated physiological (lactated Ringer's) and simulated occluded cell (5 M hydrochloric acid [HCl]) environment. Commercially pure (CP) Ti (Grade…
The preparation and characterization of high surface area ruthenium/carbon aerogel composite electrodes for use in electrochemical capacitors is reported. These new materials have been prepared by the chemical vapor impregnation of ruthenium into carbon aerogels to produce a uniform distribution of adherent ≈20 Å nano…
A systematic spectroscopic study of the ${4f}^{7}$ energy levels of ${\mathrm{Gd}}^{3+}$ in ${\mathrm{LiYF}}_{4}$ in the vacuum-ultraviolet spectral region $(50000--70000{\mathrm{cm}}^{\mathrm{\ensuremath{-}}1})$ is reported. Using energy-level calculations, all observed spectral lines could be assigned to free-ion te…
The recently developed PSI-BLAST method for sequence database search and methods for motif analysis were used to define and expand a superfamily of enzymes with an unusual nucleotide-binding fold, referred to as palmate, or ATP-grasp fold. In addition to D-alanine-D-alanine ligase, glutathione synthetase, biotin carbo…
A model of single-bubble sonoluminescence (SBSL) is constructed. In the model, the temperature is assumed to be spatially uniform inside the bubble except at the thermal boundary layer near the bubble wall even at the strong collapse based on the theoretical results of Kwak and Na [Phys. Rev. Lett. 77, 4454 (1996)]. I…
Alumina thin films with a roughness of 20 to 50 nm were formed by immersing porous alumina gel films prepared by the sol‐gel method in boiling water. When hydrolyzed fluoroalkyltrimethoxysilane was coated on the alumina films, the contact angle for water was increased with an increase of immersion time, and immersion…
We have studied the optical properties of novel semiconductor nanosheets of Ti 1 - δ □ δ O 2 4δ- (δ ∼ 0.09; □, vacancy) which were obtained by delaminating a layered titanate into elementary host layers. A uniform thickness in subnanometer scale as well as high crystallinity resulted in a sharp absorption onset with a…
Although they often appear to be permanent, metals are unstable in their service environments and are susceptible to degradation by corrosion. Corrosion occurs when protective mechanisms have been overlooked, break down, or have been exhausted, leaving the metal vulnerable to attack by hostile environments. Control of…