Human endolymphatic sac: possible mechanisms of pressure regulation

1987 ◽  
Vol 101 (8) ◽  
pp. 768-779 ◽  
Author(s):  
Phillip Ashley Wackym ◽  
Ulla Friberg ◽  
Dan Bagger-Sjöbäck ◽  
Fred H. Linthicum ◽  
Imrich Friedmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Experimental Studies ◽  
Secretory Activity ◽  
Regulatory Mechanisms ◽  
Endolymphatic Sac ◽  
Pressure Regulation ◽  
Transmission Electron ◽  
Normal Human ◽  
Mechanical Factors

AbstractThe ultrastructure of the normal human endolymphatic sac (ES) has been observed by transmission electron microscopy (TEM). The role of the epithelium, the various regions of the subepithelial space and the general anatomy of the ES in pressure regulation were morphologically studied to generate testable hypotheses of human ES function. Light microscopic (LM) and TEM evidence of pressure regulatory mechanisms by endolymph resorption, mechanical factors, and secretory activity are presented. These mechanisms may be useful in designing experimental studies of the ES, and in interpretation of retrospective LM and TEM studies of patients with Meniere's disease.

Mechanical Behavior of Cu-10ni-6Sn Spinodal Alloy

1982 ◽  
Vol 21 ◽  
Author(s):  
T. C. Lee ◽  
S. Shekhar ◽  
A. Vilassakdanont ◽  
K. N. Subramanian
Keyword(s):  
Electron Microscopy ◽  
Deformation Behavior ◽  
Experimental Studies ◽  
Total Elongation ◽  
Modulated Structure ◽  
Burgers Vector ◽  
Transmission Electron ◽  
Internal Stress Field ◽  
Theoretical Results

ABSTRACTExperimental studies on deformation behavior of Cu-10Ni-6Sn spinodal alloy specimens subjected to different aging treatments were carried out at various temperatures ranging from 77°K to 353°K, using a micro-tensile device. It was found that the total elongation was independent of aging time as long as the modulated structure was coherent. Observed slip distribution and activation energy obtained in these investigations are presented. Transmission electron microscopy of deformed specimens showed straight dislocations in as-quenched samples; they were curved and wavy in aged samples. Burgers vector analysis of the dislocations present in the deformed aged samples indicated that they were of mixed character. Preliminary theoretical results on the role of wave-squaring of the internal stress field on CRSS are also presented.

Human Endolymphatic Duct: Possible Mechanisms of Endolymph Outflow

1986 ◽  
Vol 95 (4) ◽  
pp. 409-414 ◽  
Author(s):  
Phillip A. Wackym ◽  
Ulla Friberg ◽  
Dan Bagger-Sjöbäck ◽  
Helge Rask-Andersen
Keyword(s):  
Experimental Studies ◽  
Organic Matrix ◽  
Osmotic Gradient ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Endolymphatic Duct ◽  
Transmission Electron Microscopic ◽  
Microscopic Studies ◽  
Normal Human

The ultrastructure of the normal human endolymphatic duct (ED) was observed by transmission electron microscopy. The role of the epithelium, the various regions of the subepithelial space, and vasculature in the resorption of endolymph was morphologically studied in order to generate testable hypotheses of human ED function. These hypothetical mechanisms of endolymph outflow at the level of the ED are 1) a passive transcellular movement of water across the epithelium, driven by an osmotic gradient created by a subepithelial organic matrix; 2) an active transcellular ion exchange with a passive transepithelial outflow of water, which stresses the importance of the dilated lateral intercellular spaces; and 3) an active transcellular vacuolar endolymph outflow, whereby high molecular weight substances are removed by the ED. These mechanisms may be useful in designing experimental studies of the ED and in interpretation of retrospective light microscopic and transmission electron microscopic studies of patients with Meniere's disease.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

The Role of Microscopy in Preclinical Safety Assessment

2000 ◽  
Vol 6 (S2) ◽  
pp. 998-999
Author(s):  
Barbara J. Dovey-Hartman
Keyword(s):  
Electron Microscopy ◽  
Vital Role ◽  
Pathology Report ◽  
Clinical Phase ◽  
Transmission Electron ◽  
New Chemical Entities ◽  
Regulatory Submissions ◽  
Hematoxylin And Eosin ◽  
Preclinical Safety

Microscopy plays a vital role in assessing the safety of New Chemical Entities (NCE) in the pre-clinical phase of drug development. Light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used at the Schering-Plough Research Institute (SPRI) for evaluation of NCE. To support regulatory submissions, NCE are routinely tested in rodents in short-term studies such as one-month toxicity studies, and in longterm studies such as oncogenicity studies that may last 24 months. At the completion of a study, the animals are necropsied and the required tissues collected and stored in fixative. The tissues for LM are processed to slides and stained with Hematoxylin and Eosin (H&E). The information derived from the examination of these tissues by LM becomes an essential part of the pathology report. The LM examination of these tissues usually yields the information needed to either progress a NCE or otherwise deter or halt development.

Strengthening Evaluation in a Composite Mg-RE Alloy Using TEM

2011 ◽  
Vol 678 ◽  
pp. 75-84 ◽  
Author(s):  
Marcello Cabibbo
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix ◽  
Room Temperature ◽  
Strengthening Mechanism ◽  
Composite Alloy ◽  
Specific Strength ◽  
High Specific Strength ◽  
Transmission Electron ◽  
Sic Ceramic

Magnesium alloys containing rare earth elements are known to have high specific strength and corrosion resistance. The addition of SiC ceramic particles makes the metal matrix composite stronger with better wear and creep resistance and a still good machinability. The role of the reinforcement particles to the enhanced strength can be quantitatively evaluated using transmission electron microscopy (TEM). This paper presents a quantitative strengthening evaluation in a SiC Mg-RE composite alloy. The different contributions were determined by TEM inspections. The microstructure strengthening mechanism was studied after room temperature compression specimens. The way of combining the different contributions and the comparison to the measured yield stress, is also discussed and justified.

Synthesis and Characterizations of Nanocubes, Monodispersed Nanocrystals and Nanospheres of Au

2007 ◽  
Vol 353-358 ◽  
pp. 2163-2166
Author(s):  
Ming Yang ◽  
Guo Qing Zhou ◽  
Jiang Guo Zhao ◽  
Zhan Jun Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Powder Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Scherrer Formula ◽  
Visible Absorption Spectroscopy

Nanocubes, monodispersed nanocrystals and nanospheres of Au have been prepared by a simple reaction between HAuCl4·4H2O, NaOH and NH2OH·HCl in the presence of gelatin. The role of gelatin and the affection of pH in producing the nanoparticles of Au were discussed. The products were characterized by X-ray powder diffraction, transmission electron microscopy, and UV-visible absorption spectroscopy. The sizes of the monodispersed nanocrystals of Au were estimated by Debye-Scherrer formula according to XRD spectrum.

Ordering in Compound Semiconductors: The Role of Transmission Electron Microscopy

1998 ◽  
Vol 523 ◽  
Author(s):  
D. S. Su ◽  
A. T. Tham ◽  
P. Schubert-Bischoff ◽  
I. Hähnert ◽  
W. Neumann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structure Model ◽  
Zinc Blende ◽  
Transmission Electron ◽  
Semiconductor Compounds ◽  
Ternary Semiconductor ◽  
Ternary Semiconductor Compounds ◽  
Long Range Ordering

AbstractIn this paper, the ordering of ternary semiconductor compounds is briefly reviewed by means of a coordination polyhedron model. Long-range ordering of chalcopyrite and CuAu-type structures can be represented as an array of repeating A2B2 tetrahedra. A CuAu-type ordered phase in a chalcopyrite AIBIIICVI2 compound is surrounded by an A3B+ AB3 boundary, whereas a CuPt-type ordered phase in a zinc-blende (A, B)IIICV compound is surrounded mainly by A2B2 type tetrahedra and thus restricted in size. Following the description of the ordered structure model, the detection of the asymmetry in ordering directions in (A, B)IIICV compounds is discussed. Some examples that employ transmission electron microscopy are presented.

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