摘要:

AbstractTracheal ciliary cross sections were examined with scanning transmission electron microscopy and the resultant images were digitized for image enhancement. A gray‐scale histogram of each ciliary image was produced and manipulated to enhance the image for dynein arms. Tracheal epithelial tissue from the pig, rabbit, and dog, including dogs with immotile cilia syndrome, was examined by using this technique. Tissue from each animal was fixed with each of three different fixatives and sections were evaluated for preservation of dynein arms. The same fixative did not consistently provide optimal fixation for ciliary dynein arms in all three species examined. Each species, therefore, must be evaluated to determine the optimal fixative for preservation of normal ciliary ultrastructure. Digital image processing provides a mechanism for enhancing dynein arms in situ without the need for addition of special stains or the use of techniques such as image summation. With this technique it has been shown that about two‐thirds of outer dynein arms are partially or completely missing on cilia from dogs with immotile cilia syndr

ISSN:0741-0581    

DOI:10.1002/jemt.1060080202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractMorphometric measurements are commonly carried out on structures the shape of which approximates that of a sphere. We calculated some stereological data of eosinophil granules by using digitized planimetry, performed on transmission electronmicrographs. By using a new approach for mean caliper (D) estimation and extrapolating an approximate granule axial ratio, we were able to calculate the granule density size. We deduced from a numerical analysis for various sphere sizes distributions from which an underestimation of not more than 4% may be contributed to D in most cases, assuming that the diameter coefficient of variation is less than 35%. The methodology we propose for mean ellipsoid caliper estimation seems to be useful in cases in which the disector method is not suitable.

ISSN:0741-0581    

DOI:10.1002/jemt.1060080203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractIt is a widely held belief that the products of axonal degeneration in the CNS are transitory and are caused by metabolic and phagocytic processes. However, recent light microscopic examinations of human and primate brains using the paraphenylene diamine staining method (PPD), which stains degenerating axons, have confirmed that the products of degeneration persist for years in visual pathways. The routine utilization of the PPD method for delineating human visual pathways requires further confirmation of axonal degeneration. Optic nerves, optic tracts, and lateral geniculate nuclei were collected from human brains that had clinical documentation of optic nerve damage prior to death. Optic nerves, optic tracts, and lateral geniculate nuclei taken from the brains of cynomolgus monkeys that had undergone enucleation 3 months to 1 year prior to sacrifice were also examined. All tissue was processed for electron microscopy; ultrathin sections were cut for electron microscopy, and consecutive sections were cut for light microscopy.In all cases, the homology of the degenerated processes was confirmed between the light microscopic (PPD) and the electron microscopic sections. Such ultrastructural examination demonstrates that the products of axonal degeneration remain in the primate visual system longer than previously supposed.

ISSN:0741-0581    

DOI:10.1002/jemt.1060080204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractAlthough techniques for preparing specimens for light and electron microscopy are well established, few studies have sought to establish methods for corrosion casting of the microscopic vessels of the lung. The effects of two concentrations of glutaraldehyde, formaldehyde, and no fixative (saline control) on the filling and structure of the microvascular casts of the lung were studied. All fixatives were infused 5 minutes before casting.Formaldehyde's fixation effects were intermediate between those of glutaraldehyde and no fixation. Leakage of casting material was increased in the animals that were fixed less. Digestion time was prolonged and more undigested tissue was found in the group receiving the concentrated glutaraldehyde, although the difference in neither of these features alone reached statistical significance. Circumferential bands occurred more frequently in the large vessel casts of the less fixed animals, which may account for the less filling microvasculature in these lungs. However, good quality casts were obtained with each method.

ISSN:0741-0581    

DOI:10.1002/jemt.1060080205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractWe discuss measurement of the local thickness t of a transmission microscope specimen from the log‐ratio formula t = λ In (It/I0) where Itand I0are the total and zero‐loss areas under the electron‐energy loss spectrum. We have measured the total inelastic mean free path λ in 11 materials of varying atomic number Z and have parameterized the results in the form λ = 106F (E0/Em)/ln (2βE0/Em) where F = (1 + E0/1,022)/(1 + E0/511)2, the incident energy E0is in keV, the spectrum collection semiangle β is in mrad, and Em= 7.6Z0.36. This formulation should allow absolute thickness to be determined to an accuracy of ±20% in most inorgani

ISSN:0741-0581    

DOI:10.1002/jemt.1060080206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractA comparison of transmission electron microscopy (TEM) and atom probe field‐ion microscopy (APFIM) is presented with respect to the interpretation of complex microstructures, phase identification, determination of crystallographic order, and analysis of interfaces. The capabilities, spatial resolutions, and limitations of each technique are discussed with examples taken from combined analytical electron microscopy (AEM) and APFIM studies. Both techniques are extremely powerful for routine characterization of a wide range of materials, although care must be exercised in experimentation and interpretation. The combined use of TEM and APFIM is synergistic and extends their individual capabilities from the macro scale to the atomic leve

ISSN:0741-0581    

DOI:10.1002/jemt.1060080207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractA method for preparing cross‐section transmission electron microscopy specimens from alumina and partially stabilized zirconia braze joints is described. The technique relies on masking a mechanically dimpled 3mm disc in order to avoid preferential thinning of the metallic braze filler alloy during ion milling. The results presented show that specimens made by this technique are suitable for characterizing the fine microstructural details of interfacial reactions at oxide surfaces that occur during brazin

ISSN:0741-0581    

DOI:10.1002/jemt.1060080208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractTo prevent section wrinkles usually encountered with the use of coated single‐hole grids, a simple method was developed. Formvar film resting on a platform with holes (3.5 mm diameter) was heated with a slide warmer (60–65°C). The bottom of a glass petri dish was inverted over the platform to keep the ambient air at the desired temperature. Sections were picked up from the boat of the diamond knife with a single‐hole grid and deposited at the orifice of the platform and allowed to dry. The grids were then carefully pushed through the orifice of the platform with the blunt head of a nail (3 mm dia

ISSN:0741-0581    

DOI:10.1002/jemt.1060080209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractA simple device is described that aids the processing of large numbers of tissue blocks for light or electron microscopy. The device has a number of compartments into which different tissue blocks can be placed. Each compartment has a fine mesh floor, allowing the free exchange of the reagents used in tissue processing, and a gentle flow of the reagents is promoted by a magnetic stirring bar, or a rotary mixer. All the materials used are resistant to solvents such as propylene oxide. The device is labor‐saving in that many blocks can be processed as easily as a single block. The device may also be of value in quantitative microscopy, since it ensures that all tissue blocks examined experience an identical processing histor

ISSN:0741-0581    

DOI:10.1002/jemt.1060080210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0741-0581    

DOI:10.1002/jemt.1060080211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY