bluuebunny/crossref_metadata_2025_split huggingface dataset:
A technique for revealing tissue embedded within resin blocks
Authors: Wang X.‐D. , Canny M. J. 
Published: August 2011

SUMMARYA technique is described for revealing in fine detail large pieces of tissue still embedded within rough, scratched or partly‐trimmed blocks of epoxy and other resin before sectioning. The pieces of tissue immersed in baths of oil or glycerol and illuminated by an appropriate optical system, may be photographed to provide a guide to subsequent sectioning, aiding the precise location of elements in the sections back to their position in the parent tissue, and for tracing the connections of the element between serial sections. The method has been used by the authors in sectioning for light microscopy, but could equally be used with sections for electron microscopy.
Reflection X‐ray microscopy
Authors: Franks A. , Stedman M. 
Published: August 2011

SUMMARYX‐ray microscopy has an important role to play both in microstructural studies of materials and in the examination of high temperature plasmas. Reflection microscopy offers some advantages over other types of X‐ray microscopy in the range of wavelengths which can be employed, in its potential for absorption analysis and in the ultimate resolution of about 10 nm, which may be achieved in favourable circumstances. In the first of a series of microscopes now under development, submicrometre resolution has been achieved at a wavelength of 0.8 nm.
Progress in multilayer devices as X‐ray optical elements
Authors: Dhez P. 
Published: August 2011

SUMMARYA new kind of mirror based on multilayering techniques gives the possibility of preparing artificial Bragg reflectors over all the X‐UV range. The possibility to choose most of the parameters governing the reflectivity opens the possibility to get a very good efficiency, even under normal incidence. Main parameters, evaporating techniques and tests are described. Some example of recent results are compared to the theoretical predictions.
Some theoretical aspects of type‐1 magnetic contrast in the scanning electron microscope
Authors: Wells Oliver C. 
Published: August 2011

SUMMARYType‐1 magnetic contrast can be obtained in the secondary electron (SE) image in the SEM from a sample having an external magnetic field if the SE detector is directionally sensitive. Gauss' theorem is applied to show that the normal component of induction at the surface of the sample can be calculated from the measured spatial derivative(s) of the SE difference‐signal. A method is given in this paper for calculating the three components of the induction in the entire volume above the sample surface. Reasons are given for believing that type‐1 magnetic contrast is limited in spatial resolution by the fluxon unit.
A simple re‐embedding method for the preparation of testicular cell cultures for light and electron microscopy
Authors: Jones Huw Bowen , Gray Tim J. B. 
Published: August 2011

SUMMARYA simple and reproducible method is described for the preparation of cell cultures for light and transmission electron microscopy. Mixed testicular cells are grown on collagen layered, PTFE‐coated coverslips. Thin sheets of plastic‐embedded cells are packed together and re‐embedded permitting the examination of sections cut perpendicular to the plane of the culture and, thus, the intercellular relationships at different levels throughout the culture.
Recrystallization and ice‐crystal growth in a biological specimen, as shown by a simple freeze substitution method
Authors: Steinbrecht R. A. 
Published: August 2011

SUMMARYThe sensory hairs of the silkmoth, Bombyx mori, are suitable test objects to check for recrystallization and secondary freezing damage in a biological object, because cryofixation by immersion into propane (90 K) routinely yields well‐preserved specimens without noticeable freezing damage. After rewarming the frozen specimens for 10 min to 230 K (boiling propane), the tissue preservation has not deteriorated, and even after 45 min at 230 K, ice‐crystal ghosts rarely exceed 50 nm. Two minutes at 250 K (in deep freezer) produced moderate freezing damage with ice‐crystal ghosts of 30–75 nm, whereas 90 min at 250 K resulted in severe damage with ice‐crystal ghosts well over 100 nm. Secondary freezing damage by ice‐crystal growth upon rewarming well‐frozen biological specimens, therefore, is a relatively slow process, depending not only on the temperature, but also on the exposure time. Moreover, with some biological specimens, secondary ice‐crystal growth starts at much higher temperatures than previously guessed, and with short exposure times rarely should become a hazard in fine structure work.
Contrast of biological cryosections in scanning transmission electron microscopy
Authors: Zierold Karl 
Published: August 2011

SUMMARYUltrathin (70–100 nm thick) frozen‐hydrated cryosections of yeast cells were studied by scanning transmission electron microscopy (STEM). Generally, the contrast is very poor in brightfield and increases slightly by use of the darkfield signal in imaging. The contrast can either be enhanced by selective staining before cryofixation or by mass loss caused either by freeze‐drying or by radiation damage. Partial freeze‐drying by superficial ice sublimation seems to be the most efficient method to increase the contrast in cryosections in the frozen‐hydrated state. The highest contrast in cryosections is achieved after complete freeze‐drying.
Immunocytochemical demonstrations of cytoplasmic and cell‐surface EGF receptors in A431 cells using cryo‐ultramicrotomy, surface replication, freeze‐etching and label fracture
Authors: Boonstra J. , van Belzen N. , van Maurik P. , Hage W. J. , Blok F. J. , Wiegant F. A. C. , Verkleij A. J. 
Published: August 2011

SUMMARYIn this paper we describe the use of a number of complimentary methods to visualize cytoplasmic and cell‐surface located epidermal growth factor (EGF) receptors in cultured A431 cells. Cryo‐ultramicrotomy in combination with immuno‐gold labelling will be shown to provide an excellent method in visualizing cytoplasmic located EGF receptors in addition to cell‐surface located EGF receptors. An important aspect in this method involves the possible effects of the fixatives on antigenicity. Using radioactive labelled anti EGF receptor antibodies, it was shown that formaldehyde as a fixative had no significant effect on label‐efficiency.The density and lateral distribution of EGF receptors at the cell surface has been studied by three methods, i.e. surface replication, freeze etching and label fracture, all methods in conjunction with immuno‐gold labelling. These methods allow in principle a quantitation of the surface distribution of the EGF receptors. The surface‐replication method involves, however, dehydration and critical‐point drying steps, and using radioactive labelled anti EGF receptor antibodies it was shown that in particular OsO4 fixation and dehydration caused a significant loss of cell‐associated antibodies. This disadvantage is overcome by freeze etching and the label‐fracture method, and as such these techniques provide the best methods for quantitative analysis of the planar distribution of cell‐surface located EGF‐receptors.
Normarski differential interference microscopy study of the ferroelastic domains in NaCN, RbCN and KCN
Authors: Gash Philip , Lüty Fritz 
Published: August 2011

SUMMARYPhotomicrographs of the ferroelastic domains present in the low temperature, intermediate phase of NaCN, RbCN and KCN are presented with their linear dimensions and angular orientations. The Normarski optical technique used to display the domain surfaces in colour and used to determine the small out‐of‐plane angular orientations is discussed in detail. Figures and the construction details are presented of the cold stage that allowed microscopic examination of the crystal surfaces by either reflected or transmitted light down to liquid nitrogen temperatures.
The effect of subsurface topography on secondary electron images from chromate pretreated aluminium surfaces
Authors: Treverton J. A. , Amor M. P. 
Published: August 2011

SUMMARYIn secondary and scanning transmission electron microscopes, secondary electron images of surface films can be dominated by an image derived from electrons back‐scattered from the interface between the film and the substrate. The extent of the domination has been established by studying the variation in image obtained using primary beams of different energy and by platinum coating to enhance surface secondary electron emission.Studies of thicker films also established that chemical or structural difference within a film also lead to imaging effects. In general, 5 keV electrons are the most effective in producing subsurface and structural or chemical imaging effects.
The suitability of various adhesives as mounting media for scanning electron microscopy. II. General purpose glues
Authors: Witcomb M. J. 
Published: August 2011

SUMMARYThe results presented in this paper complement those on epoxies, sprays and tapes reported in Witcomb (1981). One hundred and thirteen relatively commonly used general purpose glues or made‐up solutions have been tested with respect to possible application as scanning electron microscope specimen mounting adhesives. Recommendations are made as to the most appropriate adhesives to use.
Fast cryofixation technique for X‐ray microanalysis
Authors: Zglinicki Thomas von , Rimmler Martina , Purz Hans‐Joachim 
Published: August 2011

SUMMARYThe proposed cryofixation technique uses a tubule‐shaped needle chilled in liquid propane for simultaneous excision and freezing of a tissue specimen. Due to this simultaneity, ionic shifts created by traumatic influences are avoided even in the outermost cells of the specimen.Moreover, it is shown here that stopping the blood flow for more than about 10 s results in notable ionic shifts between cells and extracellular space in rat heart and liver. Such preparative ischaemic injury is minimized by the Fast Cryofixation Technique because it can be easily performed on organs within the circulatory system, whilst the heart of the animal is still beating.Intracellular concentrations of the monovalent ions in rat heart and liver, obtained by this method, tally well with recent results from different independent techniques reported in the literature.As demonstrated by cross‐sectioning and freeze‐fracturing, the structural preservation of the freezing technique is sufficient for X‐ray microanalytical work.
Raster images and measurement with a Vickers M86 scanning microdensitometer and interferometer by computer control
Authors: te Meerman G. J. , Anders G. J. P. A. , Wierda J. 
Published: August 2011

SUMMARYA simple and easily adaptable interface between a Vickers M86 scanning microdensitometer and microinterferometer and a Z80 CP/M based microcomputer (Zenith Z89) is described. The hardware is supplemented by a software package written in Fortran‐66, linked with an assembly routine for two‐dimensional spot control and measurement. Facilities are provided for background correction, image processing, calibration of the spot movement, correction for glare, diffraction and finite spotsize and computer‐aided focusing. Results can be plotted on a matrix printer and on a graphical unit as ruled surface plot, as isophase or isodensity contour diagram or in three‐dimensional projection with hidden line removal.
Steric hindrance in immunolabelling
Authors: Voorhout W. F. , Leunissen‐Bijvelt J. J. M. , Leunissen J. L. M. , Verkleij A. J. 
Published: August 2011

SUMMARYIn this paper we describe immunocytochemical detection of PhoE pore protein in the outer membrane of E. coli K‐12 cells in dependence of a variety of labelling approaches.Immuno‐gold labelling on ultrathin cryosections showed a uniform, dense labelling of the outer membrane of all cells. However, using immunofluorescence, whole‐mount or freeze‐etch labelling methods, labelling was limited to less than 5% of the cell population.In order to understand this phenomenon, immunoincubated cells exhibiting less than 5% labelling were processed for cryo‐ultramicrotomy. Reincubation of the sections with antibody and probe resulted in labelling of all of the cells.If an E. coli Gal‐U mutant strain, defective in the lipopolysaccharide (LPS) carbohydrate chain length, was used, each approach rendered 100% labelling.From these results it is concluded that the antigenic sites of the PhoE pore protein are not accessible in intact ‘wild‐type’ cells due to steric hindrance caused by the LPS carbohydrate chains. In cryosections this steric hindrance is partly precluded since antigenic determinants are exposed at the section surface in transversely cut membranes.Our results emphasize the necessity to compare results obtained by means of several, basically different approaches.
High resolution electron microscopy of partial dislocations in the Laves phase structure
Authors: Kitano Y. , Takata M. , Komura Y. 
Published: August 2011

SUMMARYA Mg‐base Laves phase was investigated by high resolution electron microscopy (HREM). Linear defects found at terminations of stacking faults were classified into three groups. The first is a partial dislocation at a termination of a stacking fault, the second is a superposed partial dislocation which is defined as a defect produced by a superposition of terminations of two or more stacking faults lying on neighbouring layers, and the third is a combined linear defect which consists of a characteristic combination of terminations of stacking faults. In the last case the total stacking fault vector becomes equal to the translation vector in the basal plane, so that the defect needs no relaxation of the lattice. The Burgers vectors of the partial dislocations were estimated with the aid of modified Burgers circuits.
The use of gold markers in immunocytochemical studies of microbiological organisms: a review
Authors: Beesley Julian E. 
Published: August 2011

SUMMARYColloidal gold probes have revolutionized electron immunocytochemistry and are now used extensively for microbiological studies. The gold probes can be applied in one of several methods to gain valuable information from the sample. The pre‐embedding technique, the post‐embedding technique, the immunonegative stain technique, the immunoreplica technique and the immunofreeze‐fracture technique, are each described and their applications in microbiology, for diagnosis, for the detection of the site of antigen synthesis in host cells, for vaccine production and for genetic engineering are reported.
A rapid and simple technique for correlating light microscopy, transmission and scanning electron microscopy of fixed tissues in Epon blocks
Authors: Cajander Stefan B. 
Published: August 2011

summaryA simplified and standardized technique for close correlation between light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) is described. Perfusion and immersion fixed tissue specimens were embedded in Epon 812 and cut for conventional LM and TEM. The Epon blocks with remaining tissue were thereafter treated with epoxy solvent (ethanol‐NaOH solution) for partial epoxy resin removal only (dissolving rate approx 33μm/h). The blocks with partially blotted tissue specimens were then critically point dried and gold coated for SEM. This method, in an easy way, allows repeated observations with LM, TEM and SEM with preserved fine structure and exact correlation. Since the technique is so simple and there is no need for special equipment the method can easily be adopted in all laboratories with basic SEM standards.
SEM low magnification stereoscopic technique for mapping surface contours: application to measurement of volume differences in human teeth due to polishing
Authors: Russ J. C. , Hare T. M. , Christensen R. P. , Hare K. T. , Russ J. C. 
Published: August 2011

SUMMARYSEM stereogrammetry with a low magnification mosaic of pictures is used to measure the elevation of many individual points. This random array of elevations is then connected into a triangular mesh, from which a contour map of elevation is drawn for the entire surface. Maps of surfaces before and after removal of material are used to determine the volume removed. The method is applicable to many circumstances of wear, erosion or deformation of surfaces. It is applied here to the erosion of human teeth due to dental polishing.
Fluorescence reactions of orcein: new applications for an old stain
Authors: Molero M. L. , Castillo P. Del , Stockert J. C. 
Published: August 2011

SUMMARYThe fluorescence properties of orcein are described in this paper. Under suitable exciting light, acidic solutions of orcein showed emission peaks at 587 nm (low concentration) and at 620 nm (high concentration). In fluorescence microscopy an intense orange‐red emission was found in the cytoplasm and nucleoli from acetic orcein squashes of meristematic cells, as well as in the cytoplasm of Ehrlich tumour cells and in chicken erythrocyte nuclei. When semithin sections of Epon‐embedded tissues were treated with orcein, a strong fluorescence reaction (orange‐red) appeared in starch granules, cell walls, elastin, collagen, reticulin, keratohyalin, chromatin and mucin. Cytofluorometric measurements of orcein‐stained chromatin revealed an emission peak at 585 nm with a shoulder at 620 nm. These spectroscopic and microscopical results suggest the possibility of employing orcein as a fluorochrome.
Determination of the direction of the crystal optical axis of ground uniaxial precious stones by means of polarized‐light microscope photometry
Authors: Boguth W. 
Published: August 2011

SUMMARYThe direction of the crystal optical axis of a uniaxial microscopic object is determined on the basis of the known correlation between this direction, the displacement of isogyres of the conoscopic figure, and the rotation of the microscope stage. It is shown that the use of photoelectric equipment for indicating the displacement, a stepping motor controlled by a microprocessor for rotating the stage, and a desk calculator for processing the photometric data provides a more convenient and accurate determination than classicial procedures, involving visual inspection and manual operation. The method is particularly suitable for uniaxial crystals of the size and shape of precious stones.
On double‐refracting microinterferometers which suffer from a variable interfringe spacing across the image plane
Authors: Pluta M. 
Published: August 2011

SUMMARYIt has been stated that interference fringes are asymmetrically distributed in the image plane of some double‐refracting microinterferometers. This defect is especially produced by typical birefringent Wollaston prisms and is responsible for some errors in the measurement of optical path differences. In particular, the errors arise when the interfringe spacing is directly measured in the image plane or determined from an interferogram recorded on a photographic material.
The intracellular distribution of ions and water in rat liver and heart muscle
Authors: Zglinicki Thomas von , Bimmler Martina 
Published: August 2011

SUMMARYLocal dry mass concentrations of intracellular compartments in rat heart muscle and liver cells were estimated by quantitative electron microscopy and X‐ray microanalysis of ultrathin frozen‐dried cryosections. The results were used to calculate elemental concentrations per litre of compartment water from the X‐ray microanalytical data.Water fractions were between 80.3 ± 1.3% of wet weight in the decondensed chromatin and only 45.1 ± 1.7% in mitochondria of liver cells. The lowest water fraction in heart muscle cells was also found in mitochondria. The ionic concentrations found in the cytoplasm of liver cells and in the myofibrils are in accord with the electroneutrality rule and in osmotic equilibrium with the extracellular concentrations. The concentrations of Na, K, Cl and P both in the cytoplasm and in the regions of decondensed chromatin within the nuclei were found to be equal.However, in regions of condensed chromatin K+ concentrations were found to be much higher than expected for a Donnan distribution of ions free in solution. Most probably the activity coefficient for K+ is lower in the condensed chromatin than in the decondensed or in the cytoplasm. The same holds true for the A‐band as compared to the I‐band in heart muscle cells. A sequestration of K+ was measured also in the rough endoplasmic reticulum (RER) of hepatocytes. The Cl− concentration in mitochondria both in heart muscle and liver cells has been measured far in excess of what might be expected from a Nernstian distribution. A coupled inward Cl− transport in mitochondria must, therefore, be assumed.
Electron microscopy and diffraction of icosahedral and decagonal quasicrystals in aluminium‐manganese alloys
Authors: Thangaraj N. , Subbanna G. N. , Ranganathan S. , Chattopadhyay K. 
Published: August 2011

SUMMARYElectron microscopic observations on the morphology of icosahedral and decagonal quasicrystals in aluminium‐manganese alloys have been interpreted in favour of a heterogenous nucleation mode. The transition of icosahedral quasicrystals from nonfacetted dendrites to facetted particles occurs as a function of composition. While the variety of electron diffraction patterns to be expected from icosahedral quasicrystals has been demonstrated for a number of alloys, subtle intensity differences exist among analogous patterns from Al‐Mn, Al‐Cr, Al‐Mn‐Si and Mg‐Al‐Zn‐Cu alloys. Electron diffraction patterns from decagonal quasicrystals can be understood on the basis of an edge‐centred icosahedron as opposed to a vertex‐centred icosahedron for icosahedral quasicrystals. Truncation from two‐dimensional quasicrystals is discussed.
Local translational order in the NiTi2 icosahedral quasicrystal
Authors: Zhang Z. , Kuo K. H. 
Published: August 2011

SUMMARYAfter heating to 400°C, the icosahedral quasicrystal in (Ti1‐IVI)2Ni alloys displays a kind of local or short range translational order as evidenced by a more or less commensurate arrangement of electron diffraction spots along one or several twofold directions. This is supported partly by a high resolution electron microscopic image which shows, in some parts of it, a somewhat regular arrangement of bright points. A structural model with some short‐range translation order in the range of a few nanometres along one of the fifteen twofold directions in the icosahedral matrix has been proposed and its optical diffraction pattern is in good agreement with the experimental observations.
Low‐temperature scanning tunnelling microscopy and spectroscopy on Pb and Au
Authors: Ramos M. A. , Vieira S. , Buendia A. , Baro A. M. 
Published: August 2011

SUMMARYWe have designed and built a scanning tunnelling microscope (STM) in order to work at temperatures ranging from 1·2 to 300 K. Tunnelling spectroscopy has been performed in Au and Pb with this STM. Our results on Au show different conductance‐voltage behaviours, their relation with the cleaning state of the tip being discussed. For Pb, the fitting of our I‐V characteristics to a BCS density of states gives A = 1·25 meV for the superconducting energy gap at about 5 K.