Materials Literature
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First-principles density-functional theory calculations reveal significantly different behavior between group-IIIA and IIIB delafossites $\text{Cu}M{\text{O}}_{2}$. The group-IIIA delafossites have indirect band gaps with large differences between the direct and indirect band gaps. However, this difference is small fo…
We report Gaussian basis set density functional theory (DFT) calculations of the structure and spectra of several colloidal quantum dots (QDs) with a (CdSe)(n) core (n=6,15,17), that are either passivated by trimethylphosphine oxide ligands, or unpassivated and oxidized. From the ground state geometry optimization res…
Abstract Electrospun composite mats of poly[( D,L ‐lactide) ‐co‐ glycolide] and collagen with high porosities of 85–90% and extended pore sizes of 90–130 µm were prepared to mimic the ECM morphologically and chemically. The existence of collagen molecules on the fiber surface was confirmed, enabling the cells to find…
Collagen, known for its structural role in tissues and also for its participation in the regulation of homeostatic and pathological processes in mammals, is assembled from triple helices that can be either homotrimers or heterotrimers. High resolution structural information for natural collagens has been difficult to…
We studied the electronic and optical properties of N-doped, La-doped, and N/La-codoped SrTiO 3 by means of first-principles DFT calculations to explore the physical and chemical origin of the photocatalytic activity of these structures under visible light. Our results indicate that the introduction of La into SrTiO 3…
Agents get smart: A macrocycle-based gadolinium complex undergoes an isomerization in the presence of NADH, leading to an r1 relaxivity increase of 54 %, while the intense fluorescence disappears (see scheme). This agent could facilitate the use of magnetic resonance imaging (MRI) for probing tissue redox status.
Nanotechnology in general and as it relates to drug delivery in humans has been reviewed in a two-part article, the first part of which is this paper. In this paper, nanotechnology in nature, history of nanotechnology and methods of synthesis are discussed, while also outlining its applications, benefits and risks. Na…
Perpendicularly cross-bedded CuO microstructure has been prepared via a precursor-based route. First, Cu 2 (OH) 3 Br, as the precursor, was hydrothermally synthesized in 0.1 M hexadecyl trimethyl ammonium bromide (CTAB) solution. Then the precursor was treated with 1 M NaOH solution at room temperature, and finally af…
Mode-selective surface-enhanced Raman spectroscopy (SERS) is demonstrated using plasmonic dipole antennas fabricated with electron beam lithography. An ∼10× change of the relative enhancement between two different Raman modes is observed when the resonance frequency of the plasmonic antennas is tuned over the Raman mo…
Microorganisms can complex and sequester heavy metals, rendering them promising living factories for nanoparticle production. Glutathione (GSH) is pivotal in cadmium sulfide (CdS) nanoparticle formation in yeasts and its synthesis necessitates two enzymes: gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione…
The optical spectra of hydrogen-passivated diamond clusters (diamondoids) precisely defined in size and shape have been measured in the gas phase, i.e., under an environment similar to boundary conditions typically assumed by theory. Characteristic optical properties evolve for these wide band-gap semiconductor nanocr…
We investigate the weakening of elastic materials through randomly distributed circles and cracks numerically and compare the results to predictions from homogenization theories. We find a good agreement for the case of randomly oriented cracks of equal length in an isotropic plane-strain medium for lower crack densit…
We observe both dc voltage rectification and frequency conversion that occur when a reference microwave current is injected to a MgO based magnetic tunnel junction (MTJ). The rectification that is spin-transfer torque dependent is observed when the frequency of the input microwave current coincides with the resonance…
We presents the results of an extensive numerical study of the phase diagram of the spin-1/2, \protect{$J_1$-$J_2$-$J_3$} Heisenberg model on a square lattice, for both ferromagnetic and antiferromagnetic nearest-neighbor interactions $J_1$, using exact diagonalization with periodic and twisted boundary conditions. Co…
Poly(lactic acid) (PLA) can be toughened by flexible poly(butylene adipate- co -terephthalate) (PBAT) at the cost of a certain degree of strength and modulus loss. In an attempt to achieve balanced overall properties, PLA ternary composites containing both PBAT and rigid nanoparticles, i.e., montmorillonite clay (MMT)…
This is the second part of a review on nanotechnology in general and particularly as it pertains to drug deliver. In the earlier paper (Part 1), nanotechnology in nature, its history as well as design and methodswere discussed. Its applications, benefits and risks were also outlined. In this paper (Part 2), various na…
The mechanism of hydrogen storage by atomic hydrogen spillover on a Pt-doped graphite (0001) surface was studied by means of density functional theory. The coronene molecule and a Pt 4 cluster were used as primary models for the carbon surface and the metal nanoparticles, respectively. It was found that H 2 dissociate…
A soft-template synthesis and in situ doping were applied for dispersing transition metals palladium, platinum, nickel, and ruthenium on ordered mesoporous carbons as potential adsorbents for hydrogen storage. Three metal loadings (1, 5, and 10 wt %) on the carbons were obtained to study the effects of metal concentra…
We utilize a single-atom substitution technique with spectroscopic imaging in a scanning tunneling microscope to visualize the anisotropic spatial structure of magnetic and nonmagnetic transition metal acceptor states in the GaAs (110) surface. The character of the defect states play a critical role in the properties…
Spin-state transitions, observed in many transition-metal compounds containing ${\text{Co}}^{3+}$ and ${\text{Fe}}^{2+}$, may occur with the change in temperature and pressure but also with doping, in which case the competition of single-site effects and kinetic energy of doped carriers can favor a change in the spin…