Direct evidence of the quasibound-state lifetime effect in resonant tunneling from impedance measurements

1992 ◽  
Vol 5 (8) ◽  
pp. 351-354 ◽  
Author(s):  
O. Vanbesien ◽  
V. Sadaune ◽  
D. Lippens ◽  
B. Vinter ◽  
P. Bois ◽  
...  
Keyword(s):  
Resonant Tunneling ◽  
Direct Evidence ◽  
Quasibound State ◽  
Impedance Measurements

Membrane Conductance Changes Associated with the Response of Motion Sensitive Insect Visual Neurons

1990 ◽  
Vol 45 (11-12) ◽  
pp. 1222-1224 ◽  
Author(s):  
Cole Gilbert
Keyword(s):  
Direct Evidence ◽  
Membrane Conductance ◽  
Inhibitory Input ◽  
Intracellular Recordings ◽  
Transmembrane Conductance ◽  
Visual Neurons ◽  
Impedance Measurements ◽  
Lobula Plate ◽  
Conductance Changes

Abstract Intracellular recordings and impedance measurements from directionally-selective visual interneurons of the lobula plate of flies show that during motion, transmembrane conductance increases during both depolarizing responses to preferred directions and hyperpolarizing re­sponses to anti-preferred directions. This provides direct evidence that these interneurons are postsynaptic to two separate populations of excitatory and inhibitory input elements.

Initial Stages of Molecular Beam Epitaxical Growth of Highly Strained Inxga1-XAs on Gaas (100)

1990 ◽  
Vol 202 ◽  
Author(s):  
S. Guha ◽  
A. Madhukar ◽  
R. Kapre ◽  
K. C. Rajkumar
Keyword(s):  
Electron Microscopy ◽  
Growth Temperature ◽  
Resonant Tunneling ◽  
Molecular Beam ◽  
Direct Evidence ◽  
Electrical Characteristics ◽  
Growth Morphology ◽  
Tunneling Diode ◽  
Transmission Electron ◽  
Highly Strained

ABSTRACTWe have studied the initial stages of highly mismatched InxGa1-x As growth on GaAs (100) by transmission electron microscopy (TEM). We find direct evidence of (i) deformation in the substrate below each island to depths of about 150 A and (ii) strain relief in the islands at their lateral edges. Growth morphology as a function of growth temperature is studied and it is found that the tendency for islanding for x as high as 0.5 can be supressed to a large extent by a reduction in the growth temperature. We also present results of correlation between TEM determined different growth morphologies (brought about by different growth temperatures ) and the electrical characteristics of AlAs/InxGa1-xAs resonant tunneling diode structures grown on GaAs (100).

The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

1973 ◽  
Vol 31 ◽  
pp. 574-575
Author(s):  
J. T. Stasny ◽  
R. C. Burns ◽  
R. W. F. Hardy
Keyword(s):  
Cellular Localization ◽  
Direct Evidence ◽  
Azotobacter Vinelandii ◽  
Intracellular Localization ◽  
Protein Component ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fe Protein ◽  
Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

Structural similarity of ribosomes from E. coli and A. salina

1978 ◽  
Vol 36 (2) ◽  
pp. 242-243
Author(s):  
M. Boublik ◽  
R.M. Wydro ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Ribosomal Proteins ◽  
Direct Evidence ◽  
Structural Similarity ◽  
Carbon Support ◽  
Artemia Salina ◽  
Uranyl Acetate ◽  
Biological Assays ◽  
E Coli ◽  
And Function ◽  
Fine Carbon

Ribosomes are ribonucleoprotein particles necessary for processing the genetic information of mRNA into proteins. Analogy in composition and function of ribosomes from diverse species, established by biochemical and biological assays, implies their structural similarity. Direct evidence obtained by electron microscopy seems to be of increasing relevance in understanding the structure of ribosomes and the mechanism of their role in protein synthesis.The extent of the structural homology between prokaryotic and eukaryotic ribosomes has been studied on ribosomes of Escherichia coli (E.c.) and Artemia salina (A.s.). Despite the established differences in size and in the amount and proportion of ribosomal proteins and RNAs both types of ribosomes show an overall similarity. The monosomes (stained with 0.5% aqueous uranyl acetate and deposited on a fine carbon support) appear in the electron micrographs as round particles with a diameter of approximately 225Å for the 70S E.c. (Fig. 1) and 260Å for the 80S A.s. monosome (Fig. 2).

Stress Relaxation and the Formation of Silicides in the Process of the Crystallization of NI-NB Films on SI

1991 ◽  
Vol 49 ◽  
pp. 898-899
Author(s):  
N. Rozhanski ◽  
V. Lifshitz
Keyword(s):  
Thin Films ◽  
Stress Relaxation ◽  
Integrated Circuits ◽  
Direct Evidence ◽  
Alloy Film ◽  
Diffusion Barriers ◽  
Effective Barrier

Thin films of amorphous Ni-Nb alloys are of interest since they can be used as diffusion barriers for integrated circuits on Si. A native SiO2 layer is an effective barrier for Ni diffusion but it deformation during the crystallization of the alloy film lead to the appearence of diffusion fluxes through it and the following formation of silicides. This study concerns the direct evidence of the action of stresses in the process of the crystallization of Ni-Nb films on Si and the structure of forming NiSi2 islands.

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