The influence of aluminium on iron oxides: XII. High-resolution transmission electron microscopic (HRTEM) study of aluminous goethites

Aluminium-substituted goethites are found in many soils and can also be synthesised readily in the laboratory. In recent years, synthetic substituted goethites have been examined by various techniques including XRD, IR, TEM and dissolution kinetics (Thiel, 1963; Jonas & Solymar, 1970; Fey & Dixon, 1981; Fysh & Fredericks, 1983; Schulze & Schwertmann, 1984; Schwertmann, 1984). Transmission electron microscopy (TEM) studies have shown that as Al substitution rises above 10%, the goethite needles become shorter and also thicker in the a direction. Furthermore, crystals which at zero substitution consist of domains parallel to the c axis become less domainic with increasing Al substitution (Schulze & Schwertmann, 1984).

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The blister of porphyria cutanea tarda: A Scanning and Transmission Electron Microscopic study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143298 ◽

1986 ◽

Vol 44 ◽

pp. 334-335

Author(s):

Veronika Burmeister ◽

R. Swaminathan

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Basement Membrane ◽

Middle Age ◽

Porphyria Cutanea Tarda ◽

Minor Trauma ◽

Electron Microscopic ◽

Transmission Electron Microscopic Study ◽

Transmission Electron ◽

Transmission Electron Microscopic

Porphyria cutanea tarda (PCT) is a disorder of porphyrin metabolism which occurs most often during middle age. The disease is characterized by excessive production of uroporphyrin which causes photosensitivity and skin eruptions on hands and arms, due to minor trauma and exposure to sunlight. The pathology of the blister is well known, being subepidermal with epidermodermal separation, it is not always absolutely clear, whether the basal lamina is attached to the epidermis or the dermis. The purpose of our investigation was to study the attachment of the basement membrane in the blister by comparing scanning with transmission electron microscopy.

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Morphometrical Ultrastructural Studies of the Rat's Hepatocytes Under Cooling

Microscopy and Microanalysis ◽

10.1017/s1431927600008114 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 245-246

Author(s):

A.S. Kaprelyants ◽

A.A. Kaprelyants ◽

A.N. Reylan ◽

R.K. Migunova

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electron Microscopic ◽

Rat Hepatocyte ◽

Ultrastructural Studies ◽

Transmission Electron ◽

Transmission Electron Microscopic ◽

Morphometric Methods

The aim of given investigation is to study the effect of cooling upon rat hepatocyte structure using transmission electron microscopic and computer morphometric methods. Ultrastructural and morphometrical characteristics of hepatocytes under liver cooling for various levels under in vivo and in vitro conditions were investigated. Vistar rats of 180-250 g were used in the experiment. Liver cooling (in vivo) was performed by means of original cryoapplicator with different probe temperature (1,2). Liver tissue for transmission electron microscopy was fixed in glutaraldehyde fixator on cocadylate buffer and OsO4. Dehydration was completed on acetone (3). Tissue embedding was done into the mixture of Epon/Araldite epoxy rasin. Ultrathin slices were contrasted by the method of Reinolds. Cell viewing and imaging were accomplished by electron microscope at accelerating power of 75kV.Morphometrical and stereometrical analysis was performed using the “Morpho-Tools” original computer system (c) 1994-1996 A.S. Kaprelyants, A.A. Kaprelyants, A.N. Reylan .

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Quantitative Field-Emission Transmission Electron Microscopic Study of Domain Boundaries in Cerium Doped A-Sialon Materials

Microscopy and Microanalysis ◽

10.1017/s1431927600027318 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 248-249

Author(s):

F. Xu ◽

Y. Bando ◽

C. Wang ◽

M. Mitomo

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Domain Boundary ◽

Earth Metal ◽

Partial Replacement ◽

Electron Microscopic ◽

Transmission Electron Microscopic Study ◽

Transmission Electron ◽

Domain Boundaries ◽

Transmission Electron Microscopic

α-sialon is the isostructural derivative based on the a-silicon nitride (α-Si3N4) structure by partial replacement of Si by Al and N by O. The structure is considered to be stabilized by the incorporation into the large interstices (r=0.146nm) of a metal like Li, Mg, Ca and most small rareearths. Large rare-earth metal ions have been considered not to be able to enter the interstices in α-sialon structure until several recent successes in accommodating large cerium ions (r=0.103nm). This gives rise to questions of the location and distribution of these large cerium ions within the asialon structure. It has been found that α-sialon grains formed in Ce-Si-Al-O-N system are usually rich in a new structural defect which has been considered to be initiated specifically by the presence of cerium in the lattice. This new intergrown defect is identified as domain boundary in our present study by transmission electron microscopy (TEM).

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Transmission electron microscopy enables the reconstruction of the catenane and ring forms of CS2 hydrolase

Chemical Communications ◽

10.1039/c4cc04650a ◽

2014 ◽

Vol 50 (71) ◽

pp. 10281-10283 ◽

Cited By ~ 2

Author(s):

Joseph Che-Yen Wang ◽

Adam Zlotnick ◽

Jasmin Mecinović

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Direct Evidence ◽

Protein Assemblies ◽

Electron Microscopic ◽

Transmission Electron ◽

Transmission Electron Microscopic ◽

Microscopic Studies ◽

Good Agreement

Transmission electron microscopic studies on CS2 hydrolase provide direct evidence for the existence of the hexadecameric catenane and octameric ring topologies. Reconstructions of both protein assemblies are in good agreement with crystallographic analyses.

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A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055904 ◽

1982 ◽

Vol 40 ◽

pp. 722-723 ◽

Cited By ~ 1

Author(s):

R. Gronsky

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Computer Simulations ◽

Structural Characteristics ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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