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High-resolution Technique (high-resolution + technique)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Direct Observation of Inversion Domain Boundaries of GaN on c -Sapphire at Sub-ångstrom Resolution,

ADVANCED MATERIALS, Issue 11 2008
Fude Liu
Inversion domain boundaries (IDBs) of GaN are studied by a high-resolution technique. The IDB separates adjacent domains of opposite polarity. The image shows a GaN IDB in the [bar;2110] projection. The theoretical IDB structure fits the experimentally obtained structure well. The inset is an image acquired from a very thin region on the right side of the IDB. It can indicate the polarity of GaN directly. [source]

Application of capillary electrophoresis mass spectrometry to the characterization of bacterial lipopolysaccharides

MASS SPECTROMETRY REVIEWS, Issue 1 2007
Jianjun Li
Abstract Capillary electrophoresis (CE) is a high-resolution technique for the separation of complex biological mixtures and has been widely applied to biological analyses. The coupling of capillary electrophoresis with mass spectrometry (MS) provides a powerful approach for rapid identification of target analytes present at trace levels in biological matrices, and for structural characterization of complex biomolecules. Here we review the analytical potential of combined capillary electrophoresis electrospray mass spectrometry (CE-MS) for the analysis of bacterial lipopolysaccharides (LPS). This hyphened methodology facilitates the determination of closely related LPS glycoform and isoform families by exploiting differences in their unique molecular conformations and ionic charge distributions by electrophoretic separation. On-line CE-MS also provides an additional avenue to improve detection limits, which has been successfully applied to directly probe oligosaccharide LPS glycoform populations of bacteria isolated from infected animal models without the need for further passage. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:35,50, 2007 [source]

Spectral optical coherence tomography: a new imaging technique in contact lens practice

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 2 2006
omiej J. Ka
Abstract Purpose:, Spectral optical coherence tomography (SOCT) is a new non-invasive, non-contact, high-resolution technique, which provides cross-sectional images of objects that weakly absorb and scatter light. The aim of this article is to demonstrate the application of SOCT to imaging of eyes fitted with contact lenses. Methods:, Nine eyes of six different subjects fitted with various contact lenses have been examined with a slit-lamp and a prototype SOCT instrument. Results:, Our SOCT system provides high-resolution (4,6 ,m longitudinal, 10 ,m transversal) tomograms composed of 3000,5000 A-scans with acquisition time of 100,250 ms. The quality of the images is adequate for detailed evaluation of contact lens fit. Design, shape and lens edge position were assessed, and complications of contact lens wear could be visualized. Thickness of the lens, corneal epithelium and stroma as well as the space between the lens and the eye surface have been measured. Conclusions:, SOCT allows high-resolution, cross-sectional visualization of the eye fitted with a contact lens. The ability to carry out a detailed evaluation of the fitting relationship between the lens and the ocular surface might be useful in research and optometric practice. SOCT can also be helpful in diagnosis, evaluation and documentation of contact lens complications. [source]

NMR and parity nonconservation.

CHIRALITY, Issue 10 2001
Experimental requirements to observe a difference between enantiomer signals
The possibility of observing a difference in the high-resolution NMR spectra of two enantiomers as due to parity nonconservation is discussed. Proposals to minimize the NMR linewidths are presented. It is concluded that, using the ultra- high-resolution technique, a difference could be observed with high Z value spin one- half nuclei such as Pt, T1, Xe. Other nuclei can also be considered. Chirality 13:699,702, 2001. © 2001 Wiley-Liss, Inc. [source]