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Scanning Speed (scanning + speed)
Selected AbstractsLaser-induced crystal growth of nonlinear optical Ba3Ti3O6(BO3)2 on glass surfaceCRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2008T. Oikawa Abstract Nonlinear optical Ba3Ti3O6(BO3)2 crystals were patterned on the surface of CuO (1 mol%)-doped 40BaO-40TiO2 -20B2O3 glass by irradiations of continuous-wave Nd:YAG (wavelength: ,=1064 nm) and Yb:YVO4 (,=1080 nm) lasers. Laser energies absorbed by Cu2+ ions were transferred to the lattice system through a nonradiative relaxation process, consequently heating the glass and inducing local crystallizations. For the lines patterned by Yb:YVO4 laser irradiations with a power of 1 W and a scanning speed of 20 ,m/s, a c -axis orientation of Ba3Ti3O6(BO3)2 crystals along the laser scanning direction is proposed from measurements of X-ray diffraction analyses, polarized optical photographs, polarized micro-Raman scattering spectra, and azimuthal dependence of second harmonic generations. The laser-induced crystallization technique is found to be applied successfully for the spatially selective patterning of nonlinear optical Ba3Ti3O6(BO3)2 crystals in glass. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Alterations of intraretinal layers in acute central serous chorioretinopathyACTA OPHTHALMOLOGICA, Issue 5 2009Christian Ahlers Abstract. Purpose:, Optical coherence tomography (OCT) is restricted by its low scanning speed and limited resolution. High-definition raster-scanning OCT (HD-OCT) was used to evaluate changes in retinal microstructure in patients with acute central serous chorioretinopathy (CSCR) and to find new morphological features. Methods:, Eighteen patients with subretinal fluid accumulation caused by acute CSCR were imaged in a cross-sectional study design. High-speed frequency-domain HD-OCT was used to image an area of 6 × 6 mm in the macular retina. Three-dimensional analyses were performed using en-face imaging and section analysis of single HD-OCT scans. Results:, Detailed information about fluid accumulation can be obtained in all compartments. Discrete changes in reflectivity are visualized within the outer nuclear or plexiform layers in > 90% of patients. Subretinal fluid appears as a dome-shaped pool of fluid and is not associated with a loss of photoreceptor layer integrity. Deposits are demarcated beneath the outer cone segments. Multiple small pigment epithelial detachments are present in > 60% of patients. Conclusions:, High-definition OCT provides extensive information regarding precise topographic and layer-specific localization of discrete morphological changes. Along with well-known changes in the retinal microstructure, hyper-reflectivity can be imaged in the outer nuclear or plexiform layers and may represent intraretinal changes indicating the presence of subretinal pathologies or retinal maladjustment caused by the underlying pathology. [source] High-sensitivity analysis of specific peptides in complex samples by selected MS/MS ion monitoring and linear ion trap mass spectrometry: Application to biological studiesJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 11 2007Inmaculada Jorge Abstract Mass spectrometry (MS) is a technique of paramount importance in Proteomics, and developments in this field have been possible owing to novel MS instrumentation, experimental strategies, and bioinformatics tools. Today it is possible to identify and determine relative expression levels of thousands of proteins in a biological system by MS analysis of peptides produced by proteolytic digestion. In some situations, however, the precise characterization of a particular peptide species in a very complex peptide mixture is needed. While single-fragment ion-based scanning modes such as selected ion reaction monitoring (SIRM) or consecutive reaction monitoring (CRM) may be highly sensitive, they do not produce MS/MS information and their actual specificity must be determined in advance, a prerequisite that is not usually met in a basic research context. In such cases, the MS detector may be programmed to perform continuous MS/MS spectra on the peptide ion of interest in order to obtain structural information. This selected MS/MS ion monitoring (SMIM) mode has a number of advantages that are fully exploited by MS detectors that, like the linear ion trap, are characterized by high scanning speeds. In this work, we show some applications of this technique in the context of biological studies. These results were obtained by selecting an appropriate combination of scans according to the purpose of each one of these research scenarios. They include highly specific identification of proteins present in low amounts, characterization and relative quantification of post-translational modifications such as phosphorylation and S -nitrosylation and species-specific peptide identification. Copyright © 2007 John Wiley & Sons, Ltd. [source] Microstructural characterization of laser surface melted AISI M2 tool steelJOURNAL OF MICROSCOPY, Issue 3 2010J. ARIAS Summary We describe the microstructure of Nd:YAG continuous wave laser surface melted high-speed steel, namely AISI M2, treated with different laser scanning speeds and beam diameters on its surface. Microstructural characterization of the remelted surface layer was performed using light optical and scanning electron microscopy and X-ray diffraction. The combination of the three techniques provided new insights into the substantial changes induced by laser surface melting of the steel surface layer. The advantage of the method is that it avoids the difficult and tedious work of preparing samples of this hard material for transmission electron microscopy, which is the technique normally used to study these fine microstructures. A melted zone with a dendritic structure and a partially melted zone with a heterogeneous cellular structure were observed. M2C carbides with different morphologies were identified in the resolidified surface layer after laser melting. [source] | ||||||||||