Introduction: A Symposium Dedicated to Gareth Thomas on the Occasion of his 70th Birthday

2002 ◽  
Vol 8 (4) ◽  
pp. 237-240
Author(s):  
D.G. Howitt
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Transmission Electron Microscopy ◽  
Graduate Students ◽  
70Th Birthday ◽  
The United States ◽  
Special Issue ◽  
Great Pleasure ◽  
Transmission Electron ◽  
The Creation

This symposium, and the special issue of Microscopy & Microanalysis that Barry Carter and Uli Dahmen have put together, provides us with a glimpse of a career that has not only spanned the development of electron microscopy of materials but also helped to drive it. Over the last 40 years Gareth has guided more than a hundred graduate students and over forty post-doctoral fellows, building a foundation for the application of transmission electron microscopy in the United States including the creation of the National Center for Electron Microscopy. It is with great pleasure that we celebrate his 70th birthday, gratified that he is still going strong and marveling at how he does it.

scholarly journals Scientific and Regulatory Policy Committee Points to Consider*: Review of Scientific and Regulatory Policy Committee Points to Consider: Review of Current Practices for Ultrastructural Pathology Evaluations in Support of Nonclinical Toxicology Studies

2019 ◽  
Vol 47 (4) ◽  
pp. 461-468
Author(s):  
Natalie D. Keirstead ◽  
Evan B. Janovitz ◽  
James T. Meehan ◽  
Bruce E. LeRoy ◽  
John R. Megill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Working Group ◽  
Regulatory Policy ◽  
The United States ◽  
Toxicity Studies ◽  
Ultrastructural Pathology ◽  
Transmission Electron ◽  
Policy Committee ◽  
Current Practices

Anatomic pathology and clinical pathology end points are standard components of almost every nonclinical general toxicity study conducted during the risk assessment of novel pharmaceuticals and chemicals. On occasion, an ultrastructural pathology evaluation using transmission electron microscopy (TEM) may be included in nonclinical toxicity studies. Transmission electron microscopy is most commonly used when a light microscopic finding may require further characterization that could inform on the pathogenesis and/or mechanism of action. Regulatory guidance do not address the use of TEM in general study designs nor whether these assessments should be performed in laboratories conducted in compliance with Good Laboratory Practices. The Scientific and Regulatory Policy Committee of the Society of Toxicologic Pathology (STP) formed a Working Group to assess the current practices on the use of TEM in nonclinical toxicity studies. The Working Group constructed a survey sent to members of societies of toxicologic pathology in the United States, Europe, Britain, and Japan, and responses were collected through the STP for evaluation by the Working Group. The survey results and regulatory context are discussed, as are “points to consider” from the collective experience of the Working Group. This survey indicates that TEM remains an essential diagnostic option for complementing toxicologic pathology evaluations. [Box: see text]

scholarly journals Spectrin rearrangement early in erythrocyte ghost endocytosis.

1979 ◽  
Vol 82 (3) ◽  
pp. 654-663 ◽  
Author(s):  
B Hardy ◽  
K G Bensch ◽  
S L Schrier
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Alkaline Phosphatase ◽  
Erythrocyte Membrane ◽  
Erythrocyte Ghost ◽  
Phase Microscopy ◽  
Rabbit Immunoglobulin ◽  
Transmission Electron ◽  
The Creation

The endocytic vacuoles induced in white ghosts were found to be depleted of spectrin and therefore it was proposed that they arose from spectrin-free areas in the erythrocyte membrane. To follow changes in spectrin distribution during endocytosis, affinity-purified rabbit antispectrin antibodies were produced. Quantitative techniques were developed for the use of a highly specific 125I-F(ab')2 antispectrin, and these showed that before the appearance of vacuoles, as assessed by phase microscopy, there was a reproducible decrease in immunoreactive spectrin. To determine whether this spectrin decrease represented a local or diffuse spectrin loss or a spectrin rearrangement, morphologic studies were undertaken using transmission electron microscopy on samples treated with rabbit antispectrin and ferritin-conjugated goat anti-rabbit immunoglobulin. These studies showed that endocytosis was preceded by the creation of extensive spectrin-free areas separated by discrete spectrin-containing zones. Pretreatment of ghosts with alkaline phosphatase blocked all forms of endocytosis and prevented the creation of spectrin-free areas. Therefore, it is proposed that under the impetus of endocytosis inducers, phosphorylated spectrin is redistributed so that spectrin-free zones are created, and that endocytic vacuoles form and fuse in spectrin-free areas.

scholarly journals Single-component quasicrystalline nanocrystal superlattices through flexible polygon tiling rule

Science ◽  
2018 ◽  
Vol 362 (6421) ◽  
pp. 1396-1400 ◽  
Author(s):  
Yasutaka Nagaoka ◽  
Hua Zhu ◽  
Dennis Eggert ◽  
Ou Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Computer Simulations ◽  
Building Blocks ◽  
Single Component ◽  
Atomic Scale ◽  
Transmission Electron ◽  
Nanocrystal Superlattices ◽  
The Creation

Quasicrystalline superlattices (QC-SLs) generated from single-component colloidal building blocks have been predicted by computer simulations but are challenging to reproduce experimentally. We discovered that 10-fold QC-SLs could self-organize from truncated tetrahedral quantum dots with anisotropic patchiness. Transmission electron microscopy and tomography measurements allow structural reconstruction of the QC-SL from the nanoscale packing to the atomic-scale orientation alignments. The unique QC order leads to a tiling concept, the “flexible polygon tiling rule,” that replicates the experimental observations. The keys for the single-component QC-SL formation were identified to be the anisotropic shape and patchiness of the building blocks and the assembly microscopic environment. Our discovery may spur the creation of various superstructures using anisotropic objects through an enthalpy-driven route.

Transmission Electron Microscopy-A Textbook for Materials Science, by David B. Williams and C. Barry Carter

1999 ◽  
Vol 5 (6) ◽  
pp. 452-453 ◽  
Author(s):  
Reviewed by Paul D. Brown
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Graduate Students ◽  
Materials Science ◽  
Transmission Electron ◽  
Research Scientists

When a new textbook on transmission electron microscopy is published and all of one's colleagues, established research scientists and graduate students alike, immediately go out and buy a copy–some even using their own money–then that is probably the best recommendation a book can ever get!

scholarly journals Special Issue: Advances in Transmission Electron Microscopy for the Study of Soft and Hard Matter

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1711
Author(s):  
Elvio Carlino
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Special Issue ◽  
Transmission Electron ◽  
Human Need

Transmission Electron Microscopy (TEM) owes its success to the capability to investigate fundamental aspects of nature, answering the human need of knowledge necessary to understand unknown mechanisms and to find new solutions in a variety of fields like physics, biology, medicine, engineering, or chemistry [...]

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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