Biology Commons^™

Measurement Of Fungicide Smoke Application By Electron Beam Analysis, C. R. Krause, C. C. Powell

Scanning Microscopy

Low volume fungicide smoke particle deposits were studied with scanning electron microscopy and energy dispersive X-ray analysis. Under greenhouse conditions, particles deposited on Rhododendron leaf surfaces and onto inert, carbon planchets adjacent to Rhododendron leaves were characterized by electron beam analysis. Angular particles containing chlorine, identified as vinclozolin deposition, were quantified on a per unit area basis. Leaf samples collected from plants immediately adjacent to the smoke applicator had more particles than leaf samples collected elsewhere. More deposition was measured on leaf surfaces than on inert planchet surfaces. This study increased our knowledge about the effectiveness of using less fungicide …

Fine Structure And Organ Culture Of Chick Embryo Dorsal Aorta, C. Ward Kischer, Michael Jaqua

Scanning Microscopy

Embryonic blood vessels have not been grown in organ culture, in a way which might easily submit them to studies of vascular organogenesis. The chick embryo dorsal aorta is easily accessible and relatively simple to explant to culture. Its organ culture may provide a model for wounding and repair of the intima and/or media and provide a model for studies of growth (or maintenance) and differentiation. Fresh dorsal aorta and its organ culture from the chick embryo was characterized morphologically by light microscopy scanning (SEM) and transmission electron microscopy (TEM) from days 4 to 18. Explants were incubated up to …

Crystal Associated Diseases: Role Of Scanning Electron Microscopy In Diagnosis, K. P. H. Pritzker, P. -T. Cheng, M. D. Grynpas, D. P. Holmyard

Scanning Microscopy

As crystals are important etiologic agents for disease, their accurate identification in tissues and body fluids is of utmost importance. This paper surveys the roles of crystals in disease process and outlines current analytical techniques for crystal detection and identification in bone tissues. The value of multiple correlated techniques is demonstrated including scanning electron microscopy, x-ray energy spectroscopy and powder diffraction analysis. The current feasibility of utilizing intermediate voltage scanning transmission analytical electron microscopy to integrate these analytical techniques on the same tissue sample is emphasized.

Signal Of Backscattered Electrons From Multiple Marks In Dependence On Mark Profile, D. Kaczmarek, Z. Czyżewski

Scanning Microscopy

The backscattered electron signal can be detected using a solid state detector system. Because this signal is affected by the surface topography it is necessary to determine the optimal detection condition for a registration mark detection in the electron-beam lithography and for an automatic topographical surface reconstruction.

The BSE signal from surface marks has been measured using semiconductor detectors with a small collection angle. Calculations of the BSE signal have been carried out by means of a simplified model of electron backscattering. The signal shape depends on some parameters of the mark profile, such as length, height and inclination angle …

Mounting Materials For Automated Image Analysis Of Coals Using Backscattered Electron Imaging, W. E. Straszheim, K. A. Younkin, R. T. Greer, R. Markuszewski

Scanning Microscopy

In order to apply SEM-based automated image analysis (AIA) to the characterization of not only minerals in coal but to the coal itself, sample preparation methods need to be developed beyond common practice. A significant consideration is the degree of contrast achievable between the mount media chosen and the coal. Four low-atomic number materials (epoxy, polyethylene, polystyrene and carnauba wax) were compared for their potential as suitable mounting media for coal samples. Epoxy is satisfactory only for characterization of mineral particles since the contrast between epoxy and coal particles is negligible. Polyethylene or polystyrene have marginal application for use as …

Scanning Electron Microscopic Autoradiography Of Lung, K. E. Lauhala, C. L. Sanders, K. E. Mcdonald

Scanning Microscopy

Scanning electron microscopic (SEM) autoradiography of the lung is being used to determine the distribution of inhaled, alpha particle-emitting, plutonium dioxide particles. SEM autoradiography provides high visual impact views of alpha activity. Particles irradiating the bronchiolar epithelium were detected both on the bronchiolar surface and in peribronchiolar alveoli. The technique is being used to obtain quantitative data on the clearance rates of plutonium particles from bronchi and bronchioles.

The Role Of Scanning Electron Microscopy In Ophthalmic Science, P. Versura, M. C. Maltarello

Scanning Microscopy

The eyeglobe is one of the classical domains of Scanning Electron Microscopy (SEM) in biology as it exposes several inner and outer surfaces. Both corneal and conjunctival epithelia towards the tear film as well as the corneal endothelial cells facing the anterior chamber may be accurately evaluated. The architecture of the angle and particularly the morphology of the Schlemm's canal inner wall are clarified by SEM more than by TEM serial reconstruction. The surfaces of the iris and ciliary body, the zonula and the choroidal vessel arrangement are described in great detail. Three distinct types of membrane anchoring devices are …

Preparation Of Cytoskeletons Of Cells In Culture For High Resolution Scanning And Scanning Transmission Electron Microscopy, Paul B. Bell Jr., Margaretha Lindroth, Bengt-Arne Fredriksson

Scanning Microscopy

In this tutorial we describe our methods for preparing detergent-extracted cytoskeletons for observation by high resolution scanning (SEM) and scanning transmission (STEM) electron microscopy. We both discuss the theoretical background and provide practical procedures for each of the following steps: cell culture on Formvar-coated gold grids; prefixation with aldehydes or protein crosslinking reagents (homobifunctional N-hydroxy-succinimide esters); extraction with Triton X-100 or Brij 58 detergent in microtubule stabilizing buffer; postfixation in formaldehyde and glutaraldehyde; dehydration; critical point and freeze drying; sputter coating with 1-2 nm of platinum or tungsten; and examination by SEM and both normal and inverted contrast STEM. These …

Zinc Deficiency: Specific Scalp Hair Defects Seen By Scanning Electron Microscopy May Provide A Valuable New Test, D. W. Gregory, L. Stankler

Scanning Microscopy

Zinc deficiency in man results in multisystem disease. It may be acquired or hereditary; the latter can be fatal if left untreated. Premature babies are particularly susceptible to zinc deficiency. Unfortunately no simple, reliable test for zinc status exists at present.

Short, newly-emerging scalp hair samples from 3 classical cases of zinc deficiency all showed the same characteristic abnormalities when examined by scanning electron microscopy, i.e. straight, blunt tips bearing scales, unusually thick cuticular scales with jagged free-edges, and very fine longitudinal corrugations in individual scales. These abnormal features occurring together appear to be specific for zinc deficiency; they also …

Sem Of Canine Chromosomes: Normal Structure And The Effects Of Whole-Body Irradiation, G. K. Niiro, T. M. Seed

Scanning Microscopy

Canine chromosomes are not only numerous (38 autosomal pairs), but they are small (compared to human chromosomes) and morphologically similar as well. Analysis of the canine karyotype by light microscopy (LM) of banded chromosomes is, thus, difficult, and the literature on the canine karyotype is scanty. In this study, we describe examination of chromosomes from normal and chronically irradiated dogs with the scanning elect ran microscope (SEM). Metaphase chromosomes from bone marrow aspirates were Giemsa-banded with either 0.025% trypsin alone or 0.1% trypsin preceded by 10% H2O2 and prepared for SEM. Examination of chromosomes from normal dogs revealed cylindrical chromosome …

Enamel Structure In Primates: A Review Of Scanning Electron Microscope Studies, L. B. Martin, A. Boyde, F. E. Grine

Scanning Microscopy

Comparative studies of dental enamel microstructure have involved three main areas of enquiry, with structural features having been investigated in relation to developmental mechanisms, function and/or phylogeny. The phylogenetic, or taxonomic aspect has been emphasized in the majority of studies involving the Order Primates, where efforts have focused upon attempts to recognise structural differences among various hierarchical groups.

Studies of primate enamel microstructure by SEM are reviewed here, with emphasis on what has been learned concerning the most suitable preparative techniques that can be employed, and with particular emphasis to the relevance of enamel microstructure in taxonomic analyses of living …

Microscopic Effects Of Predator Digestion On The Surfaces Of Bones And Teeth, John M. Rensberger, Hartmut B. Krentz

Scanning Microscopy

Concentrations of small fossil mammals are frequently encountered in Cenozoic deposits, but the causes for such accumulations have seldom been determined. In many cases the tooth, jaw, and limb fragments appear to be well-preserved under light microscopy, and it is difficult to differentiate damage due to predator digestion from breakage and abrasion due to physical agents. In order to find more specific evidence of predator digestion, we used a scanning electron microscope (SEM) to examine the surface microstructure of bones and teeth consumed by Bubo virginianus (great horned owl) and Canis latrans (coyote), which prey upon similar species. Effects …