High-performance genetic analysis using microfabricated capillary array electrophoresis microplates.

This review focuses on some recent advances in realizing microfabricated capillary array electrophoresis (microCAE). In particular, the development of a novel rotary scanning confocal fluorescence detector has facilitated the high-speed collection of sequencing and genotyping data from radially formatted microCAE devices. The concomitant development of a convenient energy-transfer cassette labeling chemistry allows sensitive multicolor labeling of any DNA genotyping or sequencing analyte. High-performance hereditary haemochromatosis and short tandem repeat genotyping assays are demonstrated on these devices along with rapid mitochondrial DNA sequence polymorphism analysis. Progress in supporting technology such as robotic fluid dispensing and batched data analysis is also presented. The ultimate goal is to develop a parallel analysis platform capable of integrated sample preparation and automated electrophoretic analysis with a throughput 10-100 times that of current technology.     

Second-order ferroic properties of a Pb5Ge3O11 uniaxial ferroelectric

The ferrobielastic properties (ferroic properties of the second order) earlier theoretically predicted for lead germanate uniaxial ferroelectric crystals are justified experimentally. It is demonstrated that single-domain samples are formed upon cooling to temperatures below the Curie point under uniaxial mechanical stresses corresponding to a combination of mechanical stresses σ₁₁σ₁₃ or σ₂₂σ₂₃. The macroscopic mechanism of this phenomenon is considered.     

Electronic excitation energy transfer between CdS quantum dots and carbon nanotubes

Stationary and transient photoluminescence of CdS quantum dots deposited on silicon substrates and carbon nanotubes is investigated. The photoluminescence spectrum of quantum dots on a silicon substrate is dominated by a band originating from electron transitions between the quantum-confinement levels in the dots. When the quantum dots are deposited on carbon nanotubes, the intensity of this band decreases significantly. Furthermore, the kinetics of the photoluminescence decay becomes faster, which brings evidence of an additional channel for the quantum-dot deexcitation. The analysis of the experimental data demonstrates that the Förster energy transfer from CdS quantum dots to carbon nanotubes is most probably responsible for this channel. The efficiency of this process exceeds 60%.     

A consistent and stabilized continuous/discontinuous Galerkin method for fourth-order incompressible flow problems

This paper presents a new consistent and stabilized finite-element formulation for fourth-order incompressible flow problems. The formulation is based on the C⁰-interior penalty method, the Galerkin least-square (GLS) scheme, which assures that the formulation is weakly coercive for spaces that fail to satisfy the inf-sup condition, and considers discontinuous pressure interpolations. A stability analysis through a lemma establishes that the proposed formulation satisfies the inf-sup condition, thus confirming the robustness of the method. This lemma indicates that, at the element level, there exists an optimal or quasi-optimal GLS stability parameter that depends on the polynomial degree used to interpolate the velocity and pressure fields, the geometry of the finite element, and the fluid viscosity term. Numerical experiments are carried out to illustrate the ability of the formulation to deal with arbitrary interpolations for velocity and pressure, and to stabilize large pressure gradients.     

Resonant inelastic x-ray scattering at the oxygen K resonance of NiO: nonlocal charge transfer and double-singlet excitations

We report high-resolution polarization-dependent resonant inelastic x-ray scattering (RIXS) at the O K resonance of NiO showing a rich excitation spectrum. We perform multisite Ni6O19 cluster model calculations, revealing that solid state effects are substantial. We identify a nonlocal charge transfer excitation at 4-5 eV and double-singlet creation at 1.75 eV, both exhibiting significant scattering geometry dependence. Apart from an intense band of local charge transfer excitations (above 5 eV) also dd excitations at 1 eV are observed. Finally, we point out that O K RIXS of correlated metal oxides allows a quantitative and consistent determination of the charge transfer energy delta and the Hund coupling energy J(H).     

Inelastic phonon interactions at solid–graphite interfaces

The presented model predicts thermal boundary conductance at interfaces where one material comprising the junction is characterized by high elastic anisotropy. In contrast to previous approaches, the current methodology accounts for contributions from inelastic scattering through consideration of multiple-phonon interactions. Inelastic contributions become significant as the temperature, as well as the degree of acoustic mismatch between the materials, increases. Inclusion of the inelastic interactions is necessary for a variety of interfacial systems including the metal–graphite boundary examined here. Improvement is shown over existing approaches that address only elastic scattering as both three- and four-phonon interactions significantly augment the transport.     

Molecular dynamics of star‐shaped poly(L‐lactide)s in tetrahydrofuran as solvent monitored by fluorescence spectroscopy

Linear telechelic, α,ω‐ditelechelic, and star‐shaped tri‐, tetra‐, penta‐, and hexa‐arm poly(L ‐lactide)s (PLAs) fitted at every arm with pyrene end group have been prepared. Internal dynamics and mobility of the PLA chains in tetrahydrofuran solution at 25 °C, with regard to the number of PLA arms in one macromolecule and the individual arm average degree of polymerization, was followed by fluorescence spectroscopy. Analysis of both static and time‐resolved spectra of the star‐shaped polymers revealed dynamic segmental motion resulting in end‐to‐end cyclization, accompanied by an excimer formation. Probability and rate of the latter reaction increased with increasing number of arms and with decreasing their polymerization degree. Moreover, time‐resolved measurements revealed that for macromolecules containing few arms (2 or 3) the pyrene moieties are located in the interior of the star‐shaped PLAs, whereas in the instance of the higher number of arms (4–6) they are located at the periphery of the star‐shaped PLAs. Thus, increasing the number of arms leads to their stretching away from the center of the star‐shaped PLA macromolecule. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4586–4599, 2005     

On the size of the set of points where the metric projection exists

In this paper we answer in the negative a question due to J. P. R. Christensen about almost everywhere existence of nearest points using a decomposition of ℓ₂ due to J. Matoušek and E. Matoušková. We also formulate a similar question about almost everywhere existence of farthest points and answer it in the negative. The author was supported by the grant GAČR 201/00/0767 (from the Grant Agency of the Czech Republic).     

Evaluation of adsorption energy distribution of microporous materials by a multivariant identification

The applicability of new BET-like adsorption models (uLBET and LBET formulas) for the examination of microporous materials of irregular structure is discussed. The models are intended to handle the main effects of random pore geometry on the adsorption isotherm shape. They are based on a generalized BET theory and employ simple (but realistic) adsorption energy-pore geometry relationships. To overcome numerical problems inherent in fitting any more advanced adsorption model, a multivariant identification procedure is proposed with a subset of parameters being fixed in each variant. The reliability assessment of the system parameters evaluation is stressed. The paper outlines formal and numerical bounds for adsorption measurements-based identifiability of irregular porous structures. The LBET-type formulas are recommended for the examination of such materials, as a relatively simple alternative versus DFT-based techniques. Numerous simulation results and exemplary examinations of an empirical isotherm are discussed.