bluuebunny/crossref_metadata_2025_split huggingface dataset:
The construction of a closed‐chambered incubator for use in such techniques as enzyme and immunoperoxidase histochemistry
Authors: Nusbickel Fred R. 
Published: August 2011

SUMMARYMany histochemical procedures, in an attempt to be as variable‐free as possible, often require such a quantity of incubation solution that there is a resulting waste of expensive chemical substrates, coupling salts, antigens, etc. More economic procedures are justifiably ignored in histochemical studies because of their uncontrollable variables. However, the variables associated with one such economic procedure (the drop method) can now be eliminated by utilizing the closed‐chambered incubator described in this paper. Slides containing tissue sections incubated in this apparatus need only 1 ml of incubation medium per slide to achieve a similar reaction product as tissue sections emersed in Coplin jars of medium. This incubator incorporates a water‐bath circulator to heat and circulate water below a shelf containing the tissue sections. Within 0·5 h, the entire incubating chamber is saturated with a 310 K water vapour. The water vapour eliminates the primary variable of the drop method incubation, evaporation of the medium. This paper describes the construction of the incubator, its evaluation, the savings obtained from one simple histochemical procedure and its applicability in enzyme and the immunoperoxidase histochemical techniques.
Freeze‐fracture autoradiography of the red blood cell plasma membrane
Authors: Nermut M.V. , Williams L. D. 
Published: August 2011

SUMMARYA procedure for electron microscope autoradiography of red blood cell ghosts or their outer membrane leaflets is described: sheep erythrocytes, attached to positively charged mica, were either lysed and air‐dried, or freeze‐fractured ‘by hand’ and freeze‐dried. This was followed by shadowing and carbon replication; coating with photographic emulsion; exposure in darkness at 277 K; developing and fixation; carbon coating; floating off the mica and mounting on grids. Erythrocytes iodinated with 125I using the lactoperoxidase reaction were used as a test object. The efficiency of the procedure was found to be between 3·4% and 5·6%.
A simply constructed heating stage for the scanning electron microscope
Authors: Cohen Judith M. , Hartley Kenneth J. , Waldron Malcolm B. 
Published: August 2011

SUMMARYAn easily constructed heating stage has been designed for a Cambridge Scientific Instruments' Stereoscan Scanning Electron Microscope. This heating stage is capable of reaching temperatures of at least 1273 K. The stage is a simple design which can easily be built from non‐magnetic stainless steel and a natural stone consisting mainly of pyrophyllite. All heat shielding is made from these materials without the need for any liquid coolant surrounding the stage. The use of this heating stage as an instrument for the study of morphological changes during heating processes up to 1273 K is described briefly.
An improved air‐stream incubator for use in high resolution time‐lapse cinemicrography
Authors: Arro Erik 
Published: August 2011

SUMMARYIn time‐lapse microscopy of in vitro cultivated cells it is important to keep the cells and the microscope at a stable temperature. With a conventional relay controlled air‐stream incubator the periodical fluctuations in temperature will cause a focal plane oscillation due to size variations in the cell chamber and objective lens, thus making it impossible to work at high magnifications. By substituting a TRIAC‐controlled system such fluctuations can be avoided, making high‐resolution microscopy much easier.
Comparison of hollow cone and axial bright field electron microscope imaging techniques
Authors: Freeman L. A. , Howi A. , Mistry A. B. 
Published: August 2011

SUMMARYThe use of hollow cone illumination in improving the contrast transfer in bright field high resolution electron micrographs is investigated experimentally. Analysis of the results on an optical bench indicates that, although the contrast transfer is free of sign reversals, the contrast is reduced by a factor of up to 3ṁ3 in relation to axial bright field imaging. This constitutes a severe limitation to the usefulness of the hollow cone bright field technique, particularly in situations where the signal to noise level is already poor, as in high resolution imaging of non‐crystalline specimens. Factors governing the contrast in hollow cone illumination are discussed.
Observations on the structure of amorphous arsenic by high resolution electron microscopy
Authors: Stobbs W. M. , Smith David J. 
Published: August 2011

SUMMARYResults are presented of a preliminary investigation of the structure of sputtered films of amorphous arsenic, using both high resolution bright field and tilted illumination dark field imaging modes. It is demonstrated that the material is not microcrystalline but appears to show a different form of short range order than is seen in films of amorphous carbon or germanium. The low angle scattering for the thin films was found to be very variable and it is suggested that this is associated with variability of a ‘cavern‐like’ structure and of the normal triple coordination.
Observations on the ageing of the metallic glass Fe80B20
Authors: Greer A. L. , Stobbs W. M. , Leake J. A. 
Published: August 2011

SUMMARYThe commercial binary metallic glass, Fe80B20, was examined using transmission electron microscopy after a variety of ageing treatments. While the material was found to be susceptible to beam‐induced oxidation, some tendency to crystallization at temperatures as low as 523 K was observed. Morphologically this was different from the essentially eutectic crystallization behaviour previously observed at 573 K and above.
High resolution electron microscopy of some carbonaceous materials
Authors: Iijima Sumio 
Published: August 2011

SUMMARYThe image contrast of extremely thin films of amorphous carbonaceous materials has been studied experimentally using thin supporting films of single crystal graphite. The use of thin specimens reduces the ‘overlap’ effect in imaging amorphous materials. Image contrast of their images was therefore interpreted by the ‘projected potential approximation’.Single sheets of graphitic carbon crystal were imaged with c perpendicular to the beam and their image details were compared with those of the amorphous carbon films. This comparison demonstrated that amorphous carbon films prepared by evaporation contained microcrystalline regions having graphitic structure.
The application of dark‐field electron microscopy to the study of short‐range order in alloys
Authors: Chevalier J. P. 
Published: August 2011

SUMMARYThrough the comparison of electron diffraction and high resolution dark‐field imaging from two ‘model’ short‐range ordered alloys (quenched CuPt and quenched Ni4Mo) the different nature of short‐range order in these systems is made apparent. Dark‐field stereo microscopy is used to overcome the difficulties due to the projection of the local atomic arrangement, through the foil thickness, on to a plane perpendicular to the electron beam. It is thus possible to distinguish between three‐dimensionally bound scattering regions (called microdomains, when they are associated with a crystal superstructure and have a physically realistic size) and other scattering regions, apparently due to the superposition of scattering from several locally correlated groups of atoms. In this way and through the comparison of other dark‐field images it has been shown that local ordering in CuPt is of the form of microdomains of size 0ṁ7–10 nm, with an imperfectly ordered L ***11 structure, whilst a more appropriate description of short range order for Ni4Mo is that of static concentration wave packets. The results obtained on other short‐range ordered alloys are reviewed in the light of this application.
Microspectrophotometric studies of Romanowsky stained blood cells
Authors: Galbraith William , Marshall PaulN. , Bacus JamesW. 
Published: August 2011

SUMMARYThis paper describes a microspectrophotometric study of blood smears stained by a simple, standardized Romanowsky technique, using only the dyes azure B and eosin. Absorbance spectra are presented for twenty‐two classes of cellular object, and for the two dyes in solution, together with tabulations of spectral maxima, and suitable wavelengths for use in automated image processing. The colours of objects stained with azure B/eosin are discussed in terms of absorbance spectra. By a spectral subtraction technique, it is shown that the differential colouration of various cell structures may be explained satisfactorily in terms of the varying proportions of only four dye components. These are the monomers and dimers of azure B and eosin. Polymerization was found to occur both in solution and on binding to biopolymers. A similar analysis of a conventional Romanowsky stain would present much greater difficulties, due to the greater number of dye components, which, however, contribute little to the colours observed.
A microdensitometric method for the analysis of staining kinetics
Authors: Goldstein D. J. 
Published: August 2011

SUMMARYThe rate of histological staining is in general controlled by diffusion of dye in the dyebath and/or substrate. Microdensitometric and mathematical methods for studying the rate of staining are described, and illustrated by experiments on the staining of pancreatic cytoplasmic RNA and nuclei in sections by Azure at pH 4. Under given conditions the [half‐staining time, t1/2, of RNA was about twice that of nuclei, reflecting differences in permeability or porosity. Half‐staining times were approximately doubled if the concentration of dye in the bath was reduced by 75%, suggesting that staining is not a simple first‐order process; one possible explanation for this is that rate is affected by dye diffusion both in the dyebath and in the substrate.Lowering the temperature from 298 K to 277 K increased t1/2for RNA about eightfold; the activation energy E of staining was therefore approximately 68 kJ mol−1.Assuming the substrate to consist either of plane sheets of thickness b, or uniform cylinders of radius r, equations originally proposed by Crank were applied to rate‐of‐dyeing data to calculate D/b2 and D/r2, where D is the diffusion coefficient of dye inside the substrate. From the observation that D/b2 and D/r2 decreased markedly during the staining process it was concluded that both substrates studied were heterogeneous.
Mechanisms of the Feulgen acid hydrolysis
Authors: Kjellstrand Per 
Published: August 2011

SUMMARYOur present knowledge of the two main reactions responsible for the form of the Feulgen hydrolysis curve is summarized. A suggestion that hydrolysis slightly above room temperature and in 5 M HCl is preferable is made and discussed. A formula making it possible to calculate the appropriate hydrolysis time at any normally used acid concentration and temperature is presented.
Specific techniques for the identification of O‐acylated sialic acids in colonic mucins
Authors: Culling C. F. A. , Reid P. E. 
Published: August 2011

SUMMARYThe development of methodology for the histochemistry of mucins based upon their PAS reactivity is discussed in terms of mechanism, specificity and application.Two new histochemical methods (PB/KOH/PAS and PAT/KOH/PAS), supplemented by a variety of new and standard histochemical techniques, and correlated by parallel chemical studies, were used to demonstrate and identify C4 and side chain O‐acylated sialic acids in colonic epithelial mucins.The application of these methods in the field of histopathology is discussed.
On the estimation of particle number
Authors: Orive Luis‐M. Cruz 
Published: August 2011

SUMMARYTwo methods are proposed for estimating the number of separated particles within a solid structure per unit volume of structure, Nv. Apart from being arranged with independence of any size parameter, no special assumptions upon the size, shape and orientation of the particles are made. The first method is based on the identity NV = (NA)u ṁ μu−1, where (NA)u is the mean number of particle sections per unit area of a plane probe Tu which is uniform random within the structure and perpendicular to a given direction u, whereas μu is the mean particle caliper length along u. The second method uses NV = AAṁV−1, where AA is the mean areal fraction of the particles per unit area of section, whereas v is the mean particle volume. The estimation of (NA)u, μu, and v requires the examination of parallel serial sections above and below Tu. Particle model reconstructions are not needed, however. Previous approaches to the problem are discussed.
Application of interferometry in quantitative histoenzymatic investigations
Authors: Gawlik Zbigniew , Wiśniewska Irmina Elżbieta 
Published: August 2011

SUMMARYThe interferometric technique has been used to measure the alkaline phosphatase activity in the kidney and small intestine. The effect of post‐mortem autolysis on the activity of this enzyme was checked in specimens taken from five normal rabbits. The results were entirely reproducible. The limitations of the method are discussed and the possible sources of error analysed.
An improved direct intermicroscopic (LM→SEM‐→TEM) correlative procedure for the examination of mammalian skeletal muscle
Authors: Vriend R. A. , Geissinger H. D. 
Published: August 2011

SUMMARYThe procedure for direct intermicroscopic (LM→SEM→TEM) correlation of muscle was modified. The major modification was the use of cryostat sections which showed far better ultrastructural preservation than did paraffin sections. The use of an osmium‐thiocarbohydrazide ligand binding procedure (OTOTO) did not noticeably improve the scanning electron microscopic (SEM) image, but did result in a subsequent transmission electron microscopic (TEM) image which showed increased contrast of the intracellular membranous components. Besides improving the preservation at the TEM level of examination, the techniques used to locate the same structure or area previously examined under the complementary modes of microscopy (i.e. LM and SEM), were also refined.
Dimensional changes of cultured smooth muscle cells due to preparatory processes for transmission electron microscopy
Authors: Lee R. M. K. W. , Garfield R. E. , Forrest J. B. , Daniel E. E. 
Published: August 2011

SUMMARYThe change in volume of cultured smooth muscle cells prepared with four different fixation procedures for transmission electron microscopy was studied. Although the cells showed swelling after being embedded in Spurr's embedding medium, the degree of swelling depended on the particular method of fixation procedure used. When the volume of the cells measured using transmission electron microscopy was compared with that of the fresh cell volume, cells prepared by two of the methods showed swelling, and cellular shrinkage was noted in the other two methods. One method which caused the least amount of volume change is recommended for quantitative electron microscopic study of vertebrate smooth muscle cell systems.
A real‐time optical image projection system for electron microscopy
Authors: Spence J. C. H. , Bleha W. P. 
Published: August 2011

SUMMARYThe Hughes liquid crystal light valve has been coupled to a transmission electron microscope using a fibre optics plate and transmission phosphor. This system makes it possible to reconstruct in real time, electron images in coherent or incoherent light of arbitrary intensity outside the vacuum. The experimental results reported are used to estimate the design parameters of an on‐line coherent optical diffractometer for high resolution work.
Electron microscopy applied to studies of the biological significance of defects in crocidolite asbestos
Authors: Crawford D. 
Published: August 2011

SUMMARYTransmission electron microscopy is used in an investigation of crocidolite asbestos associated with two biological systems. Control material is extremely defective and contains in particular an abundance of Wadsley defects, (100) planar faults, and pores. Fibres sectioned in lung tissue and fibres taken from in vitro exposure to blood serum show evidence of erosion by two mechanisms—preferential attack at (100) planar defects and general surface dissolution.
Acoustic microscopy of human metaphase chromosomes
Authors: Rugar D. , Heiserman J. , Minden S. , Quate C. F. 
Published: August 2011

SUMMARYAcoustic micrographs of human metaphase chromosomes have been recorded with wavelengths as short as 470 nm using liquid argon near 85 K as the acoustic wave coupling medium. Chromosomes prepared by trypsin‐Giemsa staining exhibit acoustic banding patterns similar to the G‐bands seen in optical images. Unstained chromosomes exhibit acoustic markings that do not correspond to traditional banding patterns. The observed acoustic contrast may arise from spatial variations in chromosomal mechanical properties, or from thickness variations in the fixed chromosomes.
Discriminatory X‐ray mapping of two or more elements by a pulse stretch method
Authors: Johns I. A. , Skyring G. W. 
Published: August 2011

SUMMARYA pulse‐stretch analyser attached to an Energy Dispersive Spectrophotometer for the simultaneous mapping of two or more elements is described. The circuit for the instrument is given and examples of variable spot‐size maps which may be generated, are shown by the distribution of Si, Ti and Cr in polished grains of ilmenite, garnet, spinel and clinopyroxine.
A simple aid in the evaluation of glass knives
Authors: Franchi L. L. , Symons D. 
Published: August 2011

SUMMARYThis report describes a compact, portable, self‐contained light‐box for the qualitative inspection of glass knives under a microscope. It obviates the need for elaborate illumination and viewing facilities in the microtomy laboratory when the ultramicrotome is not itself equipped with knife‐inspection devices.
The theory of the direct‐view confocal microscope
Authors: Sheppard C. J. R. , Wilson T. 
Published: August 2011

SUMMARYA theory is presented which describes imaging in both conventional and scanning microscopes. This theory embraces conventional microscopes with partially coherent source and scanning microscopes with partially coherent effective source and detector, including confocal microscopes.The theory is applicable to the direct‐view confocal microscope of Petrán̂, the design of which is discussed. This microscope combines the resolution and depth discrimination improvements of confocal microscopy with the ease of operation of the conventional microscope.
Isolated heart myocytes: ultrastructural case study technique
Authors: Robinson Thomas F. , Hayward Barbara S. , Krueger John W. , Sonnenblick Edmund H. , Wittenberg Beatrice A. 
Published: August 2011

SUMMARYWe have developed a method for performing case studies of heart muscle cells enzymatically isolated from the ventricular walls of rats that is a simple and inexpensive adaptation of procedures developed for the examination of monolayers of attached, cultured cells. The technique represents a marked departure from published accounts of electron microscopic studies of pellets or monolayers from a population of potentially heterogeneous isolated myocytes. Here we report the method, which we have used under controlled conditions with 0 mmol and 1 mmol added CaCl2, to correlate sarcomere length and electrical stimulatibility in the living state with ultrastructural features that include the relative disposition of myofilaments and the integrity of the cell coat. The degree of shrinkage during the preparative steps is less than 5%, as directly determined from photographs of striations in the living, fixed, and embedded states.
Specimen heating during sputter‐coating
Authors: Robards A. W. , Wilson A. J. , Crosby P. 
Published: August 2011

SUMMARYIt is possible to sputter thin films of gold on to surfaces of frozen biological specimens at very low temperatures (< 120 K) without untoward effects from heating. This is achieved by using permanent magnets to confine the plasma and thus to minimize the energy required to give a reasonable sputtering yield. The system described uses only 250 V at 12–15 mA to give 15 nm films within 2–3 min. It is shown, from theory portraying ‘worst‐case’ conditions, that the specimen temperature could not increase by more than 6.0 K at equilibrium. Practical results support the theoretical assumptions. Similar considerations have been applied to sputtering at normal ambient temperature where it is shown that appropriate design of simple apparatus and selection of operational conditions can give adequate films in a reasonable time with negligible (< 3 K) temperature rise above the starting temperature.
Continuous recording of microvascular dimensions with a rotating mirror microscope
Authors: Hara Akira 
Published: August 2011

SUMMARYA system which permits continuous recording of the dimensions of microscopic blood vessels is described. The system uses a combination of a rotating mirror and a pinhole aperture with a microscope to scan microvessel image signals at a rate of one per second. Image signals from the gate circuit are converted to digital signals; further conversion to analogue signals is obtained by integrating the digital signals. The analogue voltages are proportional to the vessel dimensions. A linear relationship was observed over a range of 20–200 μm (standard deviation ±3.0%). The contrast between vessels and surrounding tissue is amplified by using a B‐12 optical filter. By using this system, the mesenteric arteriole was observed after reaction with adrenaline and noradrenaline in rats. The contractile response of the arteriole to adrenaline was greater than with noradrenaline. A maximum response of 20% decrease of the vessel outer diameter is induced by 5.5 × 10−7 mmol adrenaline and 5.9 × 10−6 mmol noradrenaline.
A simple method for whole‐cell preparation in electron microscopy
Authors: Aizu Seiei , Itoh Tsunetoshi , Yamamoto Toshi Yuki 
Published: August 2011

SUMMARYA simple method for whole‐cell preparation without using gold or platinum grids as substrata for culture is described. Cells were cultured on formvar film over round pores, each 3 mm in diameter, of Thermonox coverslips. The cells on the formvar coated coverslip are fixed, stained, dehydrated in situ, and introduced into a critical point drying apparatus. A small quantity of 0.2% mesh‐cement is applied to slot grids, and they are laid onto the formvar film over the pores of the coverslip. After the grids are removed from the plastic substratum, they are ready for observation under the electron microscope.
Effects of glutaraldehyde or osmium tetroxide fixation on the osmotic properties of lung cells
Authors: Wangensteen Douglas , Bachofen Hans , Weibel Ewald R. 
Published: August 2011

SUMMARYThe osmotic properties of lung cells have been tested before and after perfusion fixation of isolated, perfused lungs with either glutaraldehyde or osmium tetroxide. The testing procedure was to add hypertonic sucrose to the perfusate for several minutes and monitor the lung weight response (an ‘osmotic transient’). Each lung was perfused with one or the other fixative solutions for 10 min, then the perfusate was changed back to Ringer‐lactate before the post‐fixation test was conducted. The results indicate that osmium tetroxide makes the cell membranes as permeable to sucrose as to water, and that sucrose thus causes no osmotic volume change. Glutaraldehyde, on the other hand, apparently preserves the impermeability of the cell membranes to sucrose, but the osmotic volume response is attenuated, indicating that significant changes in the cells have occurred.