Scanning electron microscope observations on resting sporangia of Plasmodiophora brassicae in clubroot tissues after alcohol cracking

1979 ◽  
Vol 57 (22) ◽  
pp. 2528-2532 ◽  
Author(s):  
Yosio Yukawa ◽  
Shuhei Tanaka
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Brassica Rapa ◽  
Plasmodiophora Brassicae ◽  
Ion Etching ◽  
Freeze Fracturing ◽  
Germ Pore ◽  
Tem Microscopy ◽  
Scanning Electron

Clubroot galls taken from 40-day-old Brassica rapa L. var. glabra Kitamura, grown in soil infested with Plasmodiophora brassicae Wor. were examined by scanning (SEM) and transmission (TEM) microscopy. SEM materials were prepared by freeze fracturing followed by ion etching. A thin layer enveloped the mass of sporangia which in etched specimens appeared to be embedded in a fibrillar net deposited among the sporangia. Both SEM and TEM micrographs revealed a circular germ pore (ca. 1 μm in diameter) with a thickened plug-like region in the pore orifice. The wall of the mature resting sporangium consisted of three layers W1, W2, and W3.

Microstructures of Low Angle Boundaries of the Second Generation Single Crystal Superalloy DD6

2011 ◽  
Vol 284-286 ◽  
pp. 1584-1587
Author(s):  
Zhen Xue Shi ◽  
Jia Rong Li ◽  
Shi Zhong Liu ◽  
Jin Qian Zhao
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Single Crystal ◽  
Second Generation ◽  
Three Dimensional ◽  
Single Crystal Superalloy ◽  
Transition Electron ◽  
Scanning Electron

The specimens of low angle boundaries were machined from the second generation single crystal superalloy DD6 blades. The microstructures of low angle boundaries (LAB) were investigated from three scales of dendrite, γ′ phase and atom with optical microscopy (OM), scanning electron microscope (SEM), transition electron microscope (TEM) and high resolution transmission electrion microscopy (HREM). The results showed that on the dendrite scale LAB is interdendrite district formed by three dimensional curved face between the adjacent dendrites. On the γ′ phase scale LAB is composed by a thin layer γ phase and its bilateral imperfect cube γ′ phase. On the atom scale LAB is made up of dislocations within several atom thickness.

Ion Etching of Dental Tissues in a Scanning Electron Microscope

Nature ◽  
1962 ◽  
Vol 196 (4849) ◽  
pp. 81-82 ◽  
Author(s):  
A. D. G. STEWART ◽  
A. BOYDE
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Ion Etching ◽  
Dental Tissues ◽  
Scanning Electron

Some Observations on the Formation of Wollastonite from Calcite and Quartz

1971 ◽  
Vol 8 (7) ◽  
pp. 844-851 ◽  
Author(s):  
T. M. Gordon
Keyword(s):  
Electron Microscope ◽  
Reaction Mechanism ◽  
Chemical Analysis ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Total Pressure ◽  
Initial Period ◽  
Experimental Scatter ◽  
Partial Chemical ◽  
Scanning Electron

Mixtures of powdered calcite and quartz were reacted for various lengths of time at a total pressure of 2000 bars, 650 °C, in an H2O–CO2 fluid. Extent of formation of wollastonite was determined by partial chemical analysis of run products. Experimental scatter precludes detailed analysis of the reaction mechanism.The data show that approximately 40% reaction takes place in the first 24 h, and that after this initial period the rate decreases. Examination of run products shows the calcite to be surrounded by radiating wollastonite crystals. This suggests that the wollastonite cover forms during the initial stages of reaction and, by shielding the calcite, suppresses the reaction.Single cleavage flakes of calcite were packed in −325 mesh quartz and allowed to react under the same conditions as the powders. A scanning electron microscope was used to examine and photograph the fragment surfaces at the conclusion of the experiments.Examination of the photographs shows the calcite to be completely covered with a thin layer of wollastonite crystals. Details of the morphology suggest that the wollastonite grew outward from nucleation centers and that the solution of calcite and quartz may have been accelerated near growing wollastonite. Although no details of the reaction mechanism can be deduced, the model favored here is that growth was most rapid near the calcite–wollastonite interface and the mantling effect slowed the reaction by preventing the transport of silica to the calcite surface.

Surface structure of germinating Uromyces dianthi urediospores as observed by scanning electron microscope

1971 ◽  
Vol 49 (12) ◽  
pp. 2243-2244 ◽  
Author(s):  
D. R. Jones
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Structure ◽  
Germ Tube ◽  
Spore Wall ◽  
Spore Surface ◽  
Germ Pore ◽  
Tube Emergence ◽  
Scanning Electron

Germ pore regions could not be located on the surface of Uromyces dianthi urediospores before germination. Germ tube emergence did not split the spore wall. Double spine features were observed on the spore surface.

scholarly journals Micromorphology and histochemical traits of staminal osmophores in Asphodelus aestivus Brot. flower

2012 ◽  
Vol 60 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil ◽  
Thomas Sawidis
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Light Microscope ◽  
Lipid Droplets ◽  
Basal Part ◽  
Abaxial Surface ◽  
Convex Wall ◽  
Asphodelus Aestivus ◽  
Scanning Electron

The conducted studies pertained to micromorphology of the surface of epidermis cells and histological traits of staminal filaments of <i>Asphodelus aestivus</i> Brot. flowers. The structure of the filaments was analyzed in a light microscope (LM) using various histochemical techniques. The morphology of the surface of the epidermis of filaments was observed in scanning electron microscope (SEM). Filaments <i>Asphodelus aestivus</i> accrete together with the basal part of the abaxial surface with the leaves of perianth. Their lower, wider, and flattened part surrounds the ovary. The epidermis of the staminal osmophores creates papilliose cells and unicellular hairs of various sizes. In the uppermost part of these structures, round marks in the cuticle layer after the emission of discharge were observed with the SEM. The outside, convex wall of the isodiametric cells of the epidermis, papillae and hairs was significantly thicker from the remaining walls. It was covered with cuticle of different ornamentation. The cells that created papillae and hairs had a large, centrally located vacuole and a thin layer of cytoplasm with numerous small vacuoles as well as large, often lobed nuclei. In the protoplasts of these cells the presence of plastids and lipid droplets was noted. During the time of secretion of elicitor between the wall and cuticle of the epidermis cells, convex bubbles were formed, in which the secreted substance was accumulated. At the end of secretion, on the surface of papillae, hairs and other cells of the epidermis, irregularly protruding cuticle was observed. It was noted that the composition of staminal osmophores in the flowers of <i>Asphodelus aestivus</i> includes papillae, hairs and cells of the epidermis that do not form papillae.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

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