Observation of Γ-X resonances in type-I GaAs/AlAs semiconductor superlattices: Anomaly in photoluminescence

1997 ◽  
Vol 55 (20) ◽  
pp. 13689-13696 ◽  
Author(s):  
M. Hosoda ◽  
H. Mimura ◽  
N. Ohtani ◽  
K. Tominaga ◽  
K. Fujita ◽  
...  
Keyword(s):  
Type I ◽  
Semiconductor Superlattices

Evidence forΓ−XTransport in Type-I GaAs/AlAs Semiconductor Superlattices

1995 ◽  
Vol 75 (24) ◽  
pp. 4500-4503 ◽  
Author(s):  
M. Hosoda ◽  
N. Ohtani ◽  
H. Mimura ◽  
K. Tominaga ◽  
P. Davis ◽  
...  
Keyword(s):  
Type I ◽  
Semiconductor Superlattices

scholarly journals Effective Simulations of Electronic Transport in 2D Structures Based on Semiconductor Superlattice Infinite Model

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1845
Author(s):  
Mariusz Mączka
Keyword(s):  
Electronic Transport ◽  
Type I ◽  
Transport Parameters ◽  
Semiconductor Superlattices ◽  
Accurate Analysis ◽  
Semiconductor Superlattice ◽  
Quantum Phenomena ◽  
The Green Function ◽  
Infinite Model ◽  
Method Approach

Effective simulations of semiconductor superlattices are presented in the paper. The simulations have been based on the Wannier function method approach where a new algorithm, inspired by Büttiker probes, has been incorporated into determining the Green function procedure. The program is of a modular structure, and its modules can either work independently, or interact with each other following a predefined algorithm. Such structuring not only accelerates simulations and makes the transport parameters possible to initially assess, but also enables accurate analysis of quantum phenomena occurring in semiconductor superlattices. In this paper, the capabilities of type I superlattice simulator, developed earlier, are presented, with particular emphasis on the new block where the Fermi levels are determined by applying Büttiker probes. The algorithms and methods used in the program are briefly described in the further chapters of our work, where we also provide graphics illustrating the results obtained for the simulated structures known from the literature.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Two Distinct Types of Microfilaments in the Cytoplasm of Human Adenohypophysial Cells

1973 ◽  
Vol 31 ◽  
pp. 668-669
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
I. E. Stratmann ◽  
C. Ezrin
Keyword(s):  
Pituitary Tumors ◽  
Average Diameter ◽  
Anterior Lobe ◽  
Uranyl Acetate ◽  
Type I ◽  
Breast Cancer Patients ◽  
Human Pituitary ◽  
Severe Diabetes ◽  
Pituitary Glands ◽  
Membrane Bound

Surgically removed human pituitary glands as well as pituitary tumors fixed in glutaraldehyde, postfixed in osmium tetroxide, embedded in epon resin, stained with uranyl acetate and lead citrate have been investigated by electron microscopy in order to correlate ultrastructure with functional activity. In the course of this study two distinct types of microfilaments have been identified in the cytoplasm of adenohypophysiocytes.Type I microfilaments (Fig. 1) were found in the cytoplasm of anterior lobe cells of five female subjects with disseminated mammary cancer and two patients with severe diabetes mellitus. The breast cancer patients were treated pre-operatively for various periods of time with different doses of oxysteroids. The microfilaments had an average diameter of JO A, formed parallel bundles, were scattered irregularly in the cytoplasm and were frequently located in the perikaryon. They were not membrane-bound and failed to show any periodicity.

The diagnosis of metabolic storage disease in skin biopsies (a light-, electronmicroscopic, and analytical study)

1978 ◽  
Vol 36 (2) ◽  
pp. 648-649
Author(s):  
W. Jurecka ◽  
W. Gebhart ◽  
H. Lassmann
Keyword(s):  
Storage Disease ◽  
Hunter Syndrome ◽  
Histochemical Demonstration ◽  
Sweat Glands ◽  
Type I ◽  
Storage Material ◽  
Scheie Syndrome ◽  
Storage Products ◽  
Skin Biopsies ◽  
Type V

Diagnosis of metabolic storage disease can be established by the determination of enzymes or storage material in blood, urine, or several tissues or by clinical parameters. Identification of the accumulated storage products is possible by biochemical analysis of isolated material, by histochemical demonstration in sections, or by ultrastructural demonstration of typical inclusion bodies. In order to determine the significance of such inclusions in human skin biopsies several types of metabolic storage disease were investigated. The following results were obtained.In MPS type I (Pfaundler-Hurler-Syndrome), type II (Hunter-Syndrome), and type V (Ullrich-Scheie-Syndrome) mainly “empty” vacuoles were found in skin fibroblasts, in Schwann cells, keratinocytes and macrophages (Dorfmann and Matalon 1972). In addition, prominent vacuolisation was found in eccrine sweat glands. The storage material could be preserved in part by fixation with cetylpyridiniumchloride and was also present within fibroblasts grown in tissue culture.

Methionine-Specific Staining of Collagen

1982 ◽  
Vol 40 ◽  
pp. 294-295
Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer
Keyword(s):  
Amino Acids ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Electron Microscopic ◽  
Good Correspondence ◽  
Specific Staining ◽  
Type Iii ◽  
Different Types ◽  
Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Collagen fibrillogenesis in vitro: interaction of types I and V collagen

1986 ◽  
Vol 44 ◽  
pp. 210-211
Author(s):  
Arthur J. Wasserman ◽  
Kathy C. Kloos ◽  
David E. Birk
Keyword(s):  
Type I Collagen ◽  
Corneal Stroma ◽  
Minor Component ◽  
Homogeneous Distribution ◽  
Type I ◽  
Type V Collagen ◽  
Fibril Morphology ◽  
Type V ◽  
In Vitro Interaction

Type I collagen is the predominant collagen in the cornea with type V collagen being a quantitatively minor component. However, the content of type V collagen (10-20%) in the cornea is high when compared to other tissues containing predominantly type I collagen. The corneal stroma has a homogeneous distribution of these two collagens, however, immunochemical localization of type V collagen requires the disruption of type I collagen structure. This indicates that these collagens may be arranged as heterpolymeric fibrils. This arrangement may be responsible for the control of fibril diameter necessary for corneal transparency. The purpose of this work is to study the in vitro assembly of collagen type V and to determine whether the interactions of these collagens influence fibril morphology.

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