ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00403.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00404.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYAn adaptation of the ‘correlation averaging’ method is described which allows reliable and almost fully automatic image averaging in the case of near‐periodic structures notwithstanding the presence of substantial crystal imperfections; methods for assessing resolution and symmetry without reliance on crystallinity are also discussed. Electron micrographs of negatively stained and rotary shadowed preparations of the HPI‐layer protein from the cell envelope ofMicrococcus radioduranshave been averaged using the method, and the projected structure is described to a resolution of about

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00405.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYA method is described for embedding bone and cartilage in glycol methacrylate (GMA) for light microscopy. Dehydration‐infiltration of the hard tissue is with aqueous GMA solutions minimizing solvent and dehydration artefact, and polymerization is by UV light in the cold to minimize thermal damage. Over fifty stains, enzyme localizations and related histochemical methods for 0·5–3·0 μm thick sections of GMA embedded tissue are listed. The increased resolution plus the localization of cellular and extracellular chemical moieties is now easier and more accurate providing an improved method for the study of the musculo‐skeletal system by light microscopic histoc

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00406.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYA method is described which can be used for rapidin situdeterminations of relative foil thicknesses in a transmission electron microscope, and is illustrated for the case of aluminium. A calibration curve for the foil thickness determination was obtained by measuring the relative transmission of electrons through standard thickness foils which were prepared and measured outside the electron microscope. By using this calibration curve, it was merely necessary to measure the relative transmission of electrons through an unknown specimen in order to determine its thickness.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00407.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYVibration transmitted by the specimen rod of a side‐entry stage frequently decreases image resolution, and the length of the rod in the high‐voltage electron microscope can make the problem severe. A detachable tip clamped to the translation stage minimizes the effect, but eliminates the rod as a means of tilting. Furthermore, the second tilt mechanism is usually built into the rod. Thus the sample is coupled not clamped to the rod, increasing the effect. The image resolution attainable with our double‐tilt stage was 1·5 nm along the rod's axis and 5·0 nm perpendicular to it before modification.An isotropic resolution of 0·5 nm was achieved by attaching the specimen tip to the rod with a flexible coupling and clamping both ends of the tip to the translation ring. The couplings used transmit the torque to rotate the specimen holder but dampen vibration. Ion‐pumping the vacuum system with all other pumps off also improved specimen

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00408.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYAn improved, safer, rapid method for preparing embedding plastics for electron microscopy is described. The method consists of contained storage and dispensing of individual plastic components on an automatic tare balance. The proportions are based on weight measurements and may be calculated from volume or proportion recipes. The usual problems in and resulting from embedding plastic handling have been eliminated.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00409.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYHigh resolution light microscopical images that can be superimposed on a test system for the estimation of stereological parameters are obtained by a television system modified for point‐counting morphometry. The full resolving power of the light microscope is exploited and a test system applied in the same plane as the microscopical image displayed on the monitor screen. Volume fraction estimates of nuclei and zymogen granules from the rat pancreas made with the television microscopical system and with electron‐microscopic micrographs rendered the same precision, and showed that the volume fraction of objects as small as zymogen granules was measurable with the light microscope. The measuring with the television microscopical system was about 15 times faster than with electron‐microscopic micrography and about 5 times faster than with conventional photomicrography and the light micro

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00410.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYA system is described for the automated quantitation in tissue sections of the follicular and stromal cell populations of the thyroid gland, using a computer‐linked TV image analyser. The paper illustrates how the problems of variable staining intensity and clustering of images (nuclei) may be overcome by a novel approach, in which multiple analyses of each field are made at increasing grey‐level thresholds, and then ‘synthesized’ by computer to give a composite image. Discrimination between cell (nuclear) types was by a single minimum width criterion.The results were highly reproducible and correlated well with counts obtained by a comparable manual

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00411.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYFocusing and correcting the astigmatism of an electron microscope can be time consuming and difficult to achieve accurately. An automatic method of performing these tasks using an on‐line computer system and a digital framestore has been developed. The method is applicable to noisy images in both scanning and conventional transmission electron microscopes. It is capable of setting focus and correcting astigmatism at least as accurately as can be achieved by an experienced operato

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1982.tb00412.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY