Electron microscopy of interphase chromosomes in situ; binding of permanganate to chicken erythrocytes

1976 ◽  
Vol 20 (2) ◽  
pp. 289-307
Author(s):  
H.G. Davies
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Protein Interaction ◽  
Phosphotungstic Acid ◽  
Intact Cell ◽  
Anomalous Behaviour ◽  
Protein Protein Interaction ◽  
Chicken Erythrocytes

From quantitative electron-microscope observations on the binding of permanganate to regions of erythrocytes and reticulocytes of known chemical composition, it is concluded that KMnO4, like phosphotungstic acid (PTA), binds preferentially to sites on proteins. Compared with PTA, KMnO4 binding exhibits less anomalous behaviour. The data support the hypothesis previously put forward that the 2 regions, or phases, in condensed chromatin differ in both molecular composition and concentration. The increase in binding to protein which occurs during nuclear haemolysis is interpreted in terms of protein-protein interaction in the chromatin of the intact cell.

Application of analytical electron microscopy to the study of partitioning of silicon in a 2 wt% Si eutectoid steel

1978 ◽  
Vol 36 (1) ◽  
pp. 616-617
Author(s):  
N. Ridley ◽  
S.A. Al-Salman ◽  
G.W. Lorimer
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Analytical Electron Microscopy ◽  
Eutectoid Steel ◽  
Minimum Diameter ◽  
Thin Foils ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Transformation Front

The application of the technique of analytical electron microscopy to the study of partitioning of Mn (1) and Cr (2) during the austenite-pearlite transformation in eutectoid steels has been described in previous papers. In both of these investigations, ‘in-situ’ analyses of individual cementite and ferrite plates in thin foils showed that the alloying elements partitioned preferentially to cementite at the transformation front at higher reaction temperatures. At lower temperatures partitioning did not occur and it was possible to identify a ‘no-partition’ temperature for each of the steels examined.In the present work partitioning during the pearlite transformation has been studied in a eutectoid steel containing 1.95 wt% Si. Measurements of pearlite interlamellar spacings showed, however, that except at the highest reaction temperatures the spacing would be too small to make the in-situ analysis of individual cementite plates possible, without interference from adjacent ferrite lamellae. The minimum diameter of the analysis probe on the instrument used, an EMMA-4 analytical electron microscope, was approximately 100 nm.

Remote On-Line Control of a High-Voltage in situ Transmission Electron Microscope with A Rational User Interface

1996 ◽  
Vol 54 ◽  
pp. 384-385
Author(s):  
M.A. O’Keefe ◽  
J. Taylor ◽  
D. Owen ◽  
B. Crowley ◽  
K.H. Westmacott ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
User Interface ◽  
Transmission Electron Microscope ◽  
High Voltage ◽  
Materials Science ◽  
Transmission Electron ◽  
On Line ◽  
Electron Microscopes

Remote on-line electron microscopy is rapidly becoming more available as improvements continue to be developed in the software and hardware of interfaces and networks. Scanning electron microscopes have been driven remotely across both wide and local area networks. Initial implementations with transmission electron microscopes have targeted unique facilities like an advanced analytical electron microscope, a biological 3-D IVEM and a HVEM capable of in situ materials science applications. As implementations of on-line transmission electron microscopy become more widespread, it is essential that suitable standards be developed and followed. Two such standards have been proposed for a high-level protocol language for on-line access, and we have proposed a rational graphical user interface. The user interface we present here is based on experience gained with a full-function materials science application providing users of the National Center for Electron Microscopy with remote on-line access to a 1.5MeV Kratos EM-1500 in situ high-voltage transmission electron microscope via existing wide area networks. We have developed and implemented, and are continuing to refine, a set of tools, protocols, and interfaces to run the Kratos EM-1500 on-line for collaborative research. Computer tools for capturing and manipulating real-time video signals are integrated into a standardized user interface that may be used for remote access to any transmission electron microscope equipped with a suitable control computer.

scholarly journals Oligomerization and Activity of the Helicase Domain of the Tobacco Mosaic Virus 126- and 183-Kilodalton Replicase Proteins

2003 ◽  
Vol 77 (6) ◽  
pp. 3549-3556 ◽  
Author(s):  
Sameer P. Goregaoker ◽  
James N. Culver
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Virus Replication ◽  
Protein Interaction ◽  
Gel Filtration ◽  
Helicase Domain ◽  
Protein Protein Interaction ◽  
Replicase Proteins

ABSTRACT A protein-protein interaction within the helicase domain of the Tobacco mosaic virus (TMV) 126- and 183-kDa replicase proteins was previously implicated in virus replication (S. Goregaoker, D. Lewandowski, and J. Culver, Virology 282:320-328, 2001). To further characterize the interaction, polypeptides covering the interacting portions of the TMV helicase domain were expressed and purified. Biochemical characterizations demonstrated that the helicase domain polypeptides hydrolyzed ATP and bound both single-stranded and duplexed RNA in an ATP-controlled fashion. A TMV helicase polypeptide also was capable of unwinding duplexed RNA, confirming the predicted helicase function of the domain. Biochemically active helicase polypeptides were shown by gel filtration to form high-molecular-weight complexes. Electron microscopy studies revealed the presence of ring-like oligomers that displayed six-sided symmetry. Taken together, these data demonstrate that the TMV helicase domain interacts with itself to produce hexamer-like oligomers. Within the context of the full-length 126- and 183-kDa proteins, these findings suggest that the TMV replicase may form a similar oligomer.

In situ magnetic and electronic investigation of the early stage oxidation of Fe nanoparticles using X-ray photo-emission electron microscopy

2014 ◽  
Vol 16 (48) ◽  
pp. 26624-26630 ◽  
Author(s):  
C. A. F. Vaz ◽  
A. Balan ◽  
F. Nolting ◽  
A. Kleibert
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Iron Nanoparticles ◽  
Early Stage ◽  
Photoemission Electron Microscopy ◽  
X Ray ◽  
Emission Electron ◽  
Fe Nanoparticles ◽  
Photoemission Electron

In situX-ray photoemission electron microscopy reveals the evolution of chemical composition and magnetism of individual iron nanoparticles during oxidation.

In Situ Scanning Electron Microscopy Observation of the Pattern Formation on the Surface of Al/Ge Bilayer Films

2007 ◽  
Vol 539-543 ◽  
pp. 3568-3573
Author(s):  
H. Kumagai ◽  
M. Shibata ◽  
Tomokazu Moritani ◽  
Takao Kozakai ◽  
Minoru Doi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Free Surface ◽  
Electron Microscope ◽  
Microscopy Observation ◽  
Bilayer Films ◽  
Fractal Patterns ◽  
Scanning Electron

When the Al/Ge/SiO2 bilayer films are annealed in-situ in a scanning electron microscope (SEM) at the temperatures lower than the crystallization temperature of amorphous Ge itself, the so-called metal-mediated-crystallization (MMC) takes place. In the course of MMC, crystalline Ge aggregates (Ge clusters) form in the bilayer films, which results in the formation and the evolution of impressive fractal patterns with branching on the free surface. In-situ SEM observations of annealed Al/Ge/SiO2 bilayer films indicate that the grain size of polycrystalline Al-layer influences the nucleation of Ge clusters and hence of fractal patterns. For the bilayer films containing larger Al grains, the nucleation rate of fractal patterns (Ge clusters) is faster and the number of patterns is larger.

Scanning electron microscopy of meiotic chromosomes of plants in situ

1974 ◽  
Vol 52 (6) ◽  
pp. 1438-1440 ◽  
Author(s):  
Ernest D. P. Whelan ◽  
G. H. Haggis ◽  
E. J. Ford ◽  
B. Dronzek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solanum Tuberosum ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Solanum Tuberosum L ◽  
Meiotic Spindle ◽  
Meiotic Chromosomes ◽  
Scanning Electron

Scanning electron microscope studies of anthers of the Asiatic Lilium hybrid Enchantment and Solanum tuberosum L. cv. Netted Gem fixed in organic acid – alcohol type fixatives clearly revealed nucleoli, bivalents, and the meiotic spindle. Centromere regions could not be identified in pachytene bivalents, but areas of possible spindle attachment were evident for metaphase I – anaphase I bivalents.

In Situ Transmission Electron Microscopy Observation of the Growth of Bismuth Oxide Whiskers

2008 ◽  
Vol 14 (3) ◽  
pp. 267-273 ◽  
Author(s):  
T. Mima ◽  
Y. Takeuchi ◽  
S. Arai ◽  
K. Kishita ◽  
K. Kuroda ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Bismuth Oxide ◽  
Liquid Droplet ◽  
Transmission Electron Microscopy Observation ◽  
Microscopy Observation ◽  
Vapor Liquid Solid ◽  
Transmission Electron

AbstractGrowth of bismuth oxide (most probably Bi2O3) was observed in situ in a transmission electron microscope. Bi liquid particles were dispersed on the substrates of diamond or SiO2. Introduction of oxygen up to ∼5 × 10−4 Pa resulted in formation of bismuth oxide (most probably Bi2O3) whiskers. The growth mechanism of the whisker was discussed in terms of a vapor-liquid-solid (VLS) mechanism. It is suggested that the liquid droplet of Bi acts as a physical catalyst for growth of bismuth oxide (most probably Bi2O3) whiskers.

scholarly journals Nephrocystin

2000 ◽  
Vol 11 (2) ◽  
pp. 270-282
Author(s):  
EDGAR OTTO ◽  
ANDREAS KISPERT ◽  
SILVIA SCHÄTZLE ◽  
BIRGIT LESCHER ◽  
CORNELIA RENSING ◽  
...  
Keyword(s):  
Amino Acid ◽  
Caenorhabditis Elegans ◽  
Amino Acid Sequence ◽  
Protein Interaction ◽  
Tissue Expression ◽  
Sequence Conservation ◽  
Cystic Kidney ◽  
Protein Protein Interaction ◽  
Amino Acid Sequence Conservation

Juvenile nephronophthisis, an autosomal recessive cystic kidney disease, is the primary genetic cause for chronic renal failure in children. The gene (NPHP 1) for nephronophthisis type 1 has recently been identified. Its gene product, nephrocystin, is a novel protein of unknown function, which contains a src-homology 3 domain. To study tissue expression and analyze amino acid sequence conservation of nephrocystin, the full-length murine Nphp 1 cDNA sequence was obtained and Northern and in situ hybridization analyses were performed for extensive expression studies. The results demonstrate widespread but relatively weak NPHP 1 expression in the human adult. In the adult mouse there is strong expression in testis. This expression occurs specifically in cell stages of the first meiotic division and thereafter. In situ hybridization to whole mouse embryos demonstrated widespread and uniform expression at all developmental stages. Amino acid sequence conservation studies in human, mouse, and Caenorhabditis elegans show that in nephrocystin the src-homology 3 domain is embedded in a novel context of other putative domains of protein-protein interaction, such as coiled-coil and E-rich domains. It is concluded that for multiple putative protein-protein interaction domains of nephrocystin, sequence conservation dates back at least to Caenorhabditis elegans. The previously described discrepancy between widespread tissue expression and the restriction of symptoms to the kidney has now been confirmed by an in-depth expression study.

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