Time-Dependent Images in Transmission Electron Microscopy Associated with the Phase Transitions of NbSe3

1980 ◽  
Vol 45 (21) ◽  
pp. 1696-1699 ◽  
Author(s):  
K. K. Fung ◽  
J. W. Steeds
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transitions ◽  
Time Dependent ◽  
Transmission Electron

Structural and analytical studies of the silicified macrohairs from the lemma of the grass Phalaris canariensis L

1984 ◽  
Vol 222 (1229) ◽  
pp. 427-438 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silica Particles ◽  
Time Dependent ◽  
Energy Dispersive ◽  
X Ray ◽  
Analytical Studies ◽  
Transmission Electron ◽  
Cellular Control ◽  
Phalaris Canariensis

Silicified macrohairs from mature and immature lemmas of the grass Phalaris canariensis L. have been studied by scanning (s.e.m.) and transmission electron microscopy (t.e.m.) and energy dispersive X-ray analysis (e.d.X.a.) at various times after emergence of the inflorescence. Within the macrohairs a variety of morphologies of silica particles was observed. E.d.X.a. revealed the time-dependent concentrations in the macrohairs of the elements K, Cl, P, and S, in addition to Si. Much lower levels of these elements were found in highly silicified mature macrohairs than in the immature macrohairs. It is proposed that the hairs are silicified under strict cellular control.

Oxyhemoglobin-induced apoptosis in cultured endothelial cells

1999 ◽  
Vol 91 (3) ◽  
pp. 459-465 ◽  
Author(s):  
Kotaro Ogihara ◽  
Alexander Y. Zubkov ◽  
David H. Bernanke ◽  
Adam I. Lewis ◽  
Andrew D. Parent ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endothelial Cells ◽  
Time Dependent ◽  
Dependent Manner ◽  
Content Type ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Transmission Electron ◽  
Fine Print

Object. Oxyhemoglobin (OxyHb) is one of the most important spasmogens for cerebral vasospasm that follows aneurysmal subarachnoid hemorrhage. The cytotoxic effect of OxyHb has been documented in endothelial and smooth-muscle cells; however, the pattern of cell death—necrosis or apoptosis—as the final stage of cell damage has not been demonstrated. This study was undertaken to determine if OxyHb induces apoptotic changes in cultured bovine aortic endothelial cells.Methods. Confluent bovine aortic endothelial cells were treated with OxyHb in a concentration- and time-dependent manner. Cell density was assayed by counting the number of cells that attached to culture dishes after exposure to OxyHb. To identify apoptotic changes, the investigators used three specific methods: DNA fragmentation (electrophoreses), the apoptotic body (transmission electron microscopy), and cleavage of poly (adenosine diphosphate ribose) polymerase (PARP [Western blotting]).Conclusions. Oxyhemoglobin decreased cell density in a concentration- and time-dependent manner. Analysis of DNA showed a pattern of internucleosomal cleavage characteristic of apoptosis (DNA ladder). Transmission electron microscopy demonstrated condensation of nuclei and apoptotic bodies in OxyHb-treated endothelial cells. Western blotting with the PARP antibody revealed that the 116-kD PARP was cleaved to the 85-kD apoptosis-related fragment. These results for the first time demonstrated that the OxyHb induces apoptosis in cultured endothelial cells.

Time Dependent Nucleation in a Bulk Metallic Glass Forming Alloy

1997 ◽  
Vol 481 ◽  
Author(s):  
T. K Croat ◽  
K. F. Kelton
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metallic Glass ◽  
Amorphous Matrix ◽  
Time Dependent ◽  
Glass Forming ◽  
Transmission Electron ◽  
Dependent Model ◽  
Time Dependent Model ◽  
Multiple Step

ABSTRACTThe effect of composition on the time-dependent nucleation rates in Zr65Al7.5Ni10CU17.5 glasses is investigated to better understand nucleation processes in partitioning systems. Asquenched glasses were annealed to produce a homogeneous dispersion of nanocrystals within the amorphous matrix. The nucleation rates were estimated from the number of crystallites produced as function of annealing time, using scanning and transmission electron microscopy. Experimental results for single and multiple-step annealing treatments are presented. The nucleation results are discussed briefly within the time-dependent model of the classical theory of nucleation.

scholarly journals Time Resolved Phase Transitions via Dynamic Transmission Electron Microscopy

2007 ◽  
Author(s):  
B Reed ◽  
M Armstrong ◽  
K Blobaum ◽  
N Browning ◽  
A Burnham ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transitions ◽  
Time Resolved ◽  
Transmission Electron

HRTEM analysis on phase transitions in Bi-based superconductive oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 22-23
Author(s):  
S. Horiuchi ◽  
K. Shoda ◽  
X.J. Wu ◽  
H. Nozaki ◽  
M. Tsutsumi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Phase Transitions ◽  
Structural Variation ◽  
Molten State ◽  
Critical Temperatures ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Ice Water

It is known for the superconductors in a Bi-Sr-Ca-Cu-O system that there are three phases. Bi2Sr2CuOx, Bi2Sr2CaCu2Ox and Bi2Sr2Ca2Cu3Ox, which are called for simplicity the (2201), (2212) and (2223) phases with the critical temperatures Tc at about 20, 85 and 110K respectively. Their crystal structures are closely related and the phase transition among them often occurs. When the specimen in the partially molten state was quenched to ice-water, it was composed of a Bi-rich, amorphous phase and impurity phases like Ca1−zSrzCuO2. On crystallization the former became the (2201) phase. On further heating at higher temperature firstly the (2212) phase and secondly the (2223) phase were obtained.In the present study the structural variation during the transition from the (2201) phase to the (2212) phase and further to the (2223) phase was clarified mainly by using a high-resolution transmission electron microscopy (IIRTEM). Thin specimens were prepared by ion-thinning method and observed by a 200kV TEM (JEM 2000EX). The mechanism of the phase transition was discussed from the structural viewpoint.

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