bluuebunny/crossref_metadata_2025_split huggingface dataset:
FTIR absorption study of hydroxyl ions in KHo(WO4)2 single crystals
Authors: Kovács L. , Borowiec M. T. , Majchrowski A. , Baraldi A. , Capelletti R. 
Published: February 2005

AbstractThe presence of hydroxyl ions has been detected in as‐grown KHo(WO4)2 double tungstate single crystals by Fourier Transform Infrared (FTIR) spectroscopy. The absorption bands of the stretching vibration of OH– ions have been observed between 8–300 K in the 3450–3650 cm–1 wave number range. The temperature and polarization dependences of several intense narrow absorption lines corresponding to hydroxyl ions in different environments have been studied in detail. All lines were shifted, broadened and their intensity was decreased by increasing temperature due to phonon coupling. The band intensities strongly depended on the light propagation and polarization directions, allowing the determination of the orientation of OH– dipoles with respect to the crystallographic axes. The isotopic replicas of several OH– bands have been detected between 2550–2650 cm–1 in crystals treated in D2O water vapour at 873 K. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Behaviour of surface phonons in LiCsSO4 crystal at phase transition
Authors: Trzaskowska A. , Mielcarek S. , Mroz B. 
Published: February 2005

AbstractThe paper reports results of Brillouin spectroscopy study performed on surface phonons in different crystallographic surfaces of crystals, in a wide temperature range but with particular emphasis on the temperatures covering the phase transition. The main aim of the study is to establish in which way the ferroelastic phase transition related to a strong soft bulk mode is reflected in the near‐surface region of the ferroelastic crystals. Results of the Brillouin scattering of the surface phonons propagating in the ferroelastic crystal LiCsSO4 in the temperature range covering its phase transition are presented. Surface acoustic phonons in different planes and at various depths from the surface have been studied. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of bismuth triborate single crystal using Brillouin and Raman spectroscopy
Authors: Kasprowicz D. , Runka T. , Szybowicz M. , Ziobrowski P. , Majchrowski A. , Michalski E. , Drozdowski M. 
Published: February 2005

AbstractThe bismuth triborate (BiB3O6; BIBO) single crystal has been studied by Brillouin and Raman spectroscopy. Using Brillouin spectroscopy the propagation of the acoustic phonons in [100], [010], [001], [110] and [011] directions has been analyzed. The influence of birefringent and optical activity of BIBO crystal on some acoustic phonons has been discussed. The Raman spectra of the crystal in different scattering geometries have been recorded in the 50–1500 cm‐1 spectral range at room temperature. The number and symmetry of Raman active modes was determined on the basis of site symmetry group analysis. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hologram characteristics of Mn, Tb co‐doped stoichiometric LiNbO3 single crystals
Authors: Lee H. J. , Shin T. I. , Lee S. M. , Yoon D. H. 
Published: February 2005

AbstractMn, Tb co‐doped stoichiometric LiNbO3 (Mn:Tb:SLN) single crystals of 0.5∼1.0 mm in diameter and 30∼35 mm in length were grown using the micro‐pulling down (µ‐PD) method. Mn:Tb:SLN single crystals were also grown to 20‐25 mm in diameter and 30‐35 mm in length using the Czochralski (CZ) method. The homogeneous distributions of Mn and Tb concentration were confirmed by the EPMA and defects were observed by optical microscopy. We investigated the photoluminescence (PL) and hologram grating properties of Mn:Tb:SLN single crystals. The effect of concentration of dopant MnO2 and Tb4O7 on the luminescnce properties of the Mn:Tb:LiNbO3 single crystals excited by laser line 325 nm, 488 nm and 514 nm is reported. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of Al‐Cu‐Co single quasicrystals by X‐ray topography
Authors: Bogdanowicz W. 
Published: February 2005

AbstractAl‐Cu‐Co single quasicrystals were studied by the reflective X‐ray topography. It was found that on the surfaces of the single quasicrystals, which were parallel to (00001) decagonal plane, the contrast associated with screw dislocation occurs. In the topograms taken from other surfaces of the single quasicrystals the bands of contrast appear. This contrast comes from the antiphase domains and depends on the conditions of the single quasicrystals growth process. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Early stages of low temperature epitaxial growth of InSb on GaAs
Authors: Borowska A. , Gutek J. , Czajka R. , Oszwaldowski M. , Richter A. 
Published: February 2005

AbstractEarly stages of the growth of the low‐temperature InSb under‐layer in the two‐stage method of the heteroepitaxial growth of InSb layers on GaAs substrates are studied. The investigated orientations are: (100), (111)A, (111)B, (110) planes and (110) plane misoriented by 3° towards the <100> direction. The investigated deposits are prepared by the flash evaporation method. InSb deposits having an average layer thickness between 2 nm and 10 nm consist of separate grains with a grain diameter of around 30 nm. Independent of the substrate orientation, they are oriented in conformity with the substrate, confirming that the initial mode of the growth is that of Stransky‐Krastanov. Annealing of the layers at 470 °C improves the crystallinity of the grains. The same annealing of 30 nm thick layers results in a decrease in their resistance and the surface roughness. The greatest changes are observed in the (100) oriented layers, and the smallest changes are observed in the (110) oriented layers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aqueous Phase One‐Electron Reduction of Sulfonium, Selenonium and Telluronium Salts
Authors: Eriksson Per , Engman Lars , Lind Johan , Merényi Gabor 
Published: February 2005

AbstractTriorganylsulfonium, ‐selenonium and ‐telluronium salts were reduced by carbon dioxide radical anions/solvated electrons produced in aqueous solution by radiolysis. The radical expulsion accompanying reduction occurred with the expected leaving group propensities (benzyl > secondary alkyl > primary alkyl > methyl > phenyl), although greater than expected loss of the phenyl group was often observed. Diorganyl chalcogenides formed in the reductions were conveniently isolated by extraction with an organic solvent. Product yields based on the amount of reducing radicals obtained from the γ‐source were often higher than stoichiometric (up to 1800 %) in the reduction of selenonium and telluronium compounds; it is likely that this result can be accounted for in terms of a chain reaction with carbon‐centred radicals/formate serving as the chain transfer agent. The product distribution was essentially independent of the reducing species for diphenyl alkyl telluronium salts, whereas significant variations were seen for some of the corresponding selenonium salts. This would suggest the intermediacy of telluranyl radicals in the one‐electron reduction of telluronium salts. However, pulse radiolysis experiments indicated that the lifetimes of such a species (the triphenyltelluranyl radical) would have to be less than 1 μs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis of Functionalized Nitrogen Heterocycles by Radical Decarboxylation of β‐ and γ‐Amino Acids
Authors: Boto Alicia , Hernández Rosendo , de León Yolanda , Murguía José R. , Rodriguez‐Afonso Abigail 
Published: February 2005

AbstractIodinated or oxygenated nitrogen heterocycles are obtained by radical decarboxylation of β‐ and γ‐amino acids. This mild, versatile reaction is applied to the synthesis of bioactive products, such as 4‐arylpiperidines, hydroxylated piperidines, and new antifungal agents.
Parallel‐recording systems for electron energy loss spectroscopy (EELS)
Authors: Egerton R. F. 
Published: February 2005

AbstractThe present report paper deals with the use of a photodiode array for recording electron energy loss spectra in a transmission electron microscope. Important properties of the array are outlined, together with a description of the circuitry needed for interfacing the output to a multichannel analyser.In the direct‐exposure mode, the device can easily detect a single (80 or 100 keV) electron, allowing inner‐shell energy losses between 200 eV and 2000 eV to be recorded in about 10 seconds. By signal averaging a large number of readouts, a dynamic range of at least 105 is possible. Irradiation damage to the array can be controlled by cooling the array and by various anealing procedures. Sensitivity and DQE are lower, but the dynamic range is higher in the indirect mode, where a fluorescent screen is used to convert the electrons into visible photons, which are then imaged onto the diodes. The choice of screen material and of optical coupling to the array are discussed. Several spectral artifacts are described, together with spectrum‐processing techniques designed to remove them.
The usefulness of glutaraldehyde‐carbohydrazide copolymerization in biological specimen stabilization for scanning electron microscopy
Authors: Gunning William T. , Crang Richard E. 
Published: February 2005

AbstractBiological specimens can be prepared for scanning electron microscopy by means of copolymerizing the fixing agent glutaraldehyde with carbohydrazide prior to air drying. Such preparations are more stable in the electron microscope, show less internal cellular disruption and retain more of their native elemental composition than specimens prepared by means of dehydration and critical‐point drying. Specimens observed in the scanning electron microscope can often be recovered for thin sectioning with no additional embedment, and can then be observed by means of transmission elecltron microscopy. The preparation (termed GACH) can be performed in almost any laboratory with no specialized equipment and, for the most part, may be carried out at room temperature. The technique appears to provide the promise of further research applications in scanning electron microscopy which may employ conjugated procedures of immunocytochemistry and cathodoluminescence as well as X‐ray microanalysis in limited situations.
Energy‐dispersive X‐ray microanalysis of aqueous biologic samples on bulk supports
Authors: Roman Richard J. , Hatchell Marion 
Published: February 2005

AbstractThe present investigation describes a modification of the liquid droplet technique that allows for the quantitative elemental analysis of small volumes (< 100 picoliters) of aqueous biologic samples using a scanning transmission electron microscope (Philips 400 HTG‐STEM) equipped with an EDAX energy dispersive detector. Aliquots of samples and standards were micropipetted onto solid beryllium supports under paraffin oil. The oil was washed with organic solvents and the samples frozen and freeze‐dried. The samples were excited in a Philips 400‐HTG‐STEM by scanning a 1‐μm, 20‐kV electron beam over the surface of the droplets, and the X‐ray spectra were collected. Measured X‐ray intensities in characteristic peaks were found to be linearly related to the concentration of various elements in the sample. This work demonstrates the feasibility of performing quantitative elemental analysis of minute samples and cells in a scanning transmission electron microscope equipped with an energy dispersive X‐ray detector.
Intelligent interface for a microprocessor controlled scanning transmission electron microscope with x‐ray imaging
Authors: Kowarski David 
Published: February 2005

AbstractAn intelligent interface has been designed to perform synchronous digital image acquistion and scan generation (SDIASG interface) for a microprocessor controlled Scanning Transmission Electron Microscope (S(T)EM) with x‐ray imaging. The SDIASG interface connects an LSI‐11/2 microprocessor to a Philips EM400 electron microscope. The LSI‐11/2 microprocessor is part of a DeAnza VC5000 digital image display system. A system using the SDIASG interface is described. The system takes advantage of the SDIASG interface and a DeAnza VC5000 digital image display system to realize new capabilities that optimize conditions for x‐ray mapping.A low characteristic x‐ray count rate is generated by the ultrathin specimens from which high resolution x‐ray maps can be obtained (Shuman et al, 1976; Somlyo and Shuman, 1982). This low count rate necessitates a long image accumulation time, which in turn makes drift correction essential for maintaining spatial resolution. The new capabilities of the system described here consist of real‐time display and summation of consecutive image and x‐ray maps, and automatic return to a high speed imaging mode between consecutive x‐ray map passes. The new capabilities combine to allow frequent correction for specimen drift between consecutive x‐ray mapping passes while still permitting a long total accumulation time for the x‐ray maps.
A procedure for rupture‐free preparation of confluently grown monolayer cells for scanning electron microscopy
Authors: Schroeter Dieter , Spiess Eberhard , Paweletz Neidhard , Benke Rosemarie 
Published: February 2005

AbstractMonolayers of PtK‐1 and HeLa cells grown on glass or plastic supports are extremely susceptible to lacerations, e.g., splits and cracks caused mainly by shrinkage when prepared for scanning electron microscopy (SEM). We find that a four‐step fixation procedure including glutaraldehyde, OsO4, tannic acid, and uranylacetate application, in combination with critical point drying, drastically reduces these structural damages. In addition, the conductivity of the specimens is enhanced, so that they can be investigated without gold coating. Transmission electron microscopy (TEM) investigation of perpendicular sections in the area of lacerations provides evidence that the subcortical cytoskeletal elements are of crucial importance in maintaining cell membrane stability during the preparations. Our relatively quick and simple procedure results in an improved structural appearance of the cells.
Protein A‐gold electron microscopic immunocytochemistry: Methods, applications, and limitations
Authors: Bendayan Moïse 
Published: February 2005

AbstractThe postembedding protein A‐gold immunocytochemical approach has been introduced as an alternative to other techniques for the ultrastructural localization of antigenic sites. The present review deals with the development, the theoretical background, and technical approach of the protein A‐gold method as well as the different modifications introduced in order to enhance the resolution of the results and to perform double labelings on the same section. Various examples demonstrate the reliability and the wide range of application of this technique. In addition, some problems, pitfalls, and limitations particular to this method are reported.
Application of the Laplacian filter to high‐resolution enhancement of SEM images
Authors: Oho Eisaku , Baba Norio , Katoh Masaru , Nagatani Takashi , Osumi Masako , Amako Kazunobu , Kanaya Koichi 
Published: February 2005

AbstractCertain digital image‐processing methods, which are useful for nonperiodic structural images, have been applied to high‐resolution SEM images for the improvement of resolution. Samples utilized in the present study consisted of magnetic tape coated with gold, T4 phage coated with gold‐palladium, and uncoated specimens of Prolamellar body (PLB) in Cucurbita moschata. These images were blurred and otherwise disturbed by electronic noise, though the images were taken at the limit of efficiency of intrinsic instrument. The major image‐processing tool was the Laplacian filter, which subtracts the Laplacian from the original image. Noise, which is a serious problem in digital processing of high‐resolution SEM images, was suppressed by the nonlinear type smoothing method. Also, the noise was evaluated by an autocorrelation function and a power spectrum of the image. By using these methods of “deblurring” and noise removal, we achieved better resolution, and structural details of our biological specimens were revealed.
Electron crystal structure analysis of small organic molecules
Authors: Dorset Douglas L. 
Published: February 2005

AbstractElectron crystallography of small organic molecules, i.e., electron diffraction crystal structure analysis, has been long recognized to possess definite advantages over neutron and x‐ray diffraction techniques for the investigation of microcrystalline preparations. Quantitative application of the technique to real structural problems, on the other hand, had been hindered initially by an inadequate theoretical model. Yet, as demonstrated in this review of the methodology, the adequate recognition of limiting factors due to n‐beam dynamical scattering and crystal deformation permits design of optimal diffraction experiments which yield intensity data suitable for ab initio structure analysis. Representative crystallographic analyses discussed here underscore the utility of this technique as a probe of organic molecular structure at atomic resolution.
Localization of proteins on viral nucleocapsids using immunoelectron microscopy
Authors: Murti K. G. , Portner A. , Troughton K. , Deshpande K. 
Published: February 2005

AbstractWe have described an indirect immunoelectron microscope method to localize individual proteins on viral nucleocapsids using monoclonal antibodies and colloidal gold‐conjugated second antibodies. The procedure provides good binding and retention of antibodies, good resolution(< 24nm), and negligible nonspecific binding of antibodies to the background. In addition, the method is compatible with both negative and positive staining, the two staining procedures commonly used to derive ultrastructural information on viral chromosomes. We have illustrated the procedure by localizing the NP (nucleoprotein, ≈︁ 2,600 copies) and P (polymerase‐associated protein, ≈︁ 300 copies) proteins on the nucleocapsid of Sendai virus, a paramyxovirus.
Cautions, common sense, and rationale for the electron microscopy laboratory
Authors: Smithwick Eleanor B. 
Published: February 2005

AbstractThis paper is a condensation of precautions, general information, and common‐sense tips designed to assist students in electron microscopy. Although not all circumstances are included and many of the recommendations are common sense, this handout has proven invaluable to beginners in two different multiuser electron microscopy facilities. When integrated by discussion and testing into the initial training period, this information will save the neophyte, lab manager, and others working in a multiuser facility untold hours of frustration, of wasted time, effort, and supplies, and of exposure to the myriad environmental hazards inherent in the performance of electron microscopy. The rationale for these suggestions is included, enhancing problem‐solving in situations not covered directly in this presentation.
Structural and electron diffraction data for sapphire (α‐al2o3)
Authors: Lee W. E. , Lagerlof K. P. D. 
Published: February 2005

AbstractCrystallographic and electron diffraction data for sapphire (α‐Al2O3) are presented which enable ready and unique identification of TEM diffraction patterns and facilitate image analysis. Crystallographic data is presented in the form of stereographic projections and in figures listing angles between planes and angles between zones. Electron diffraction data consist of computer‐simulated diffraction patterns and tables of extinction distances calculated using atomic and ionic electron scattering factors.
Current basis for the ultrastructural clinical diagnosis of tumors: A review
Authors: Russo José , Tait Larry , Russo Irma H. 
Published: February 2005

AbstractThe ultrastructural diagnosis of tumors requires a careful analysis that should be done in an orderly fashion. It requires precise planning from the time of specimen collection to the selection of the area to be examined. Pictures must be taken systematically and every micrograph should allow to answer whether the number of cells photographed is adequate; whether mitoses are present, what is the pattern of the tumor; what is the appearance of the cell membrane; whether the cells are joined by junctional complexes; whether free surfaces possess microvilli or cilia; what organelles are present and how they are distributed; whether there are secretory granules, melanosomes, or other cytoplasmic elements. Nuclear and nucleolar size and shape have to be taken into consideration. The composition of the interstitial extracellular matrix is important in certain types of tumors. Although these questions are not the only ones to be addressed, their use in a logical fashion is helpful when it concerns the ultrastructural diagnosis.
Metal evaporation shadowing: A computer simulation
Authors: Colquhoun William , Sokol Roger , Davison Edwin , Cassimeris Lynne 
Published: February 2005

AbstractThis paper addresses the question of what is the very best deposition that can be achieved by metal evaporation shadowing. It deals, therefore, with the resolution attainable in metal shadowed specimens. The analysis disregards interatomic attractions (nucleation, crystallite formation, decoration) and generates depositions solely on the basis of probabilities of vacant, single, and multiple atom landings at different points on a substrate.The treatment starts by showing that random number generation can be used to simulate reasonably the evaporation of metal atoms from a shadowing source and their deposit on a substrate. A Fortran program tabulates and displays these simulated atom landings. The analysis shows that one can never expect to obtain a perfectly uniform deposit; some areas will always be heavily filled while others will be lightly filled or vacant. Resolution is thereby limited. The analysis shows how a deposit becomes more uniform as the number of atoms deposited increases. It predicts optimal amounts of deposition for various shadowing angles. The analysis also provides a rationale for the way in which deposition grain coarsens and resolution worsens as the angle of shadow is made more steep.Computer‐generated “ideal” depositions are compared with real shadow grains achieved under equivalent experimental conditions. The simulations are also compared with deposits achieved by novel shadowing methods. Ways to improved metal evaporation technique are suggested by the analysis and these are discussed.