Fertilization membranes structure analysis with the surface replica method

The behavior of structures, machine or components made of composite materials or light high-performance alloys is still a great concern for applications in which high strength-to-mas-ratio is a fundamental requirement. Procedures to detect flaws of small initial cracks and evaluate fatigue crack growth are nowadays essentials for high performance flying or ground machines (airplanes, automobiles,...). Structural reliability and structural health monitoring are considered in this paper and the surface replica method is deepened. Numerical FEM models were developed to assist the surface replica method analysis of the results. Ti6Al4V alloy was considered. This paper is a short technical communication.

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Fine Structure of Sea Urchin Sperm Membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068552 ◽

1970 ◽

Vol 28 ◽

pp. 312-313

Author(s):

S. Inoue ◽

A. Buday ◽

G.H. Cousineau

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Sea Urchin ◽

Sea Water ◽

Sea Urchins ◽

Water Mixture ◽

Thin Sections ◽

Surface Replica ◽

Sperm Membrane ◽

Surface Replica Method

From electron microscope studies of thin sections it is known that the entire surface of a spermatozoon of sea urchin is covered by a plasma membrane, or sperm membrane, of an approximate thickness of 100Å (1). In these experiments the surface replica method was applied for the study of the fine structure of the sperm membrane.Spermatozoa from Strongylocentrotus purpuratus (sea urchins supplied by the Pacific Biomarine Supply Company, Venice, Calif.) were washed several times by centrifugation in Millipore-filtered sea water. After fixation in a 2.5% glutaraldehyde-paraformaldehyde (sea water mixture at 4°C) for an hour, spermatozoa were washed with sea water and then with distilled water for several times. A few drops of specimen were dried on a glass slide and the surface replica was prepared according to the method previously described (2) with the exception that the spermatozoa were decomposed in 18 N H2SO4 for about 20 hours at room temperature. The replica films were examined with a JEM-7A electron microscope.

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Fatigue crack initiation at Nd-rich particles in an Nd containing high temperature titanium alloy

Journal of Materials Research ◽

10.1557/jmr.1997.0341 ◽

1997 ◽

Vol 12 (10) ◽

pp. 2571-2574 ◽

Cited By ~ 6

Author(s):

J. F. Lei ◽

Q. J. Wang ◽

Y. Y. Liu ◽

S. X. Guan ◽

Z. G. Wang ◽

...

Keyword(s):

Fatigue Crack ◽

High Temperature ◽

Crack Initiation ◽

Tensile Axis ◽

Fatigue Crack Initiation ◽

Growth Direction ◽

The Matrix ◽

Surface Replica ◽

Surface Replica Method ◽

Experimental Findings

Scanning electron microscopy (SEM) and surface replica method have been employed to study the micromechanism of fatigue crack initiation at Nd-rich phase particles in a high temperature titanium (Ti-55) alloy. It was found that the microcrack initiates near the equator of Nd-rich particles in the matrix. The microcrack grows first at an angle of about 45° with respect to the tensile axis, and then its growth direction becomes approximately normal to the tensile axis. The experimental results are analyzed in terms of the elastic stress distribution around soft particles imbedded in the matrix to account for the experimental findings of particle cracking and the associated surface microcrack initiation near the particle “equator.” A model of fatigue crack initiation at a soft surface particle is proposed.

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Oncornavirus assembly at the cell surface revealed in replicas of freeze-dried cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082637 ◽

1978 ◽

Vol 36 (2) ◽

pp. 354-355

Author(s):

Anthony Demsey ◽

Christopher W. Stackpole

Keyword(s):

Cell Surface ◽

Surface Membrane ◽

Viral Origin ◽

Intact Cells ◽

Structural Formation ◽

Virus Core ◽

Freeze Dried ◽

Cacodylate Buffer ◽

Surface Replica ◽

Leukemia Viruses

The murine leukemia viruses are type-C oncornaviruses, and their release from the host cell involves a “budding” process in which the newly-forming, RNA-containing virus core becomes enveloped by modified cell surface membrane. Previous studies revealed that the released virions possess a dense array of 10 nm globular projections (“knobs”) on this envelope surface, and that these knobs contain a 70, 000 MW glycoprotein (gp70) of viral origin. Taking advantage of this distinctive structural formation, we have developed a procedure for freeze-drying and replication of intact cells which reveals surface detail superior to other surface replica techniques, and sufficient to detect even early stages of virus budding by localized aggregation of these knobs on the cell surface.Briefly, cells growing in monolayer are seeded onto round glass coverslips 10-12 mm in diameter. After a period of growth, cells are fixed in situ for one hour, usually with 1% OsO4 in 0. 1 M cacodylate buffer, and rinsed in distilled water.

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New replica method with plasma polymerized film by glow discharge

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104133 ◽

1988 ◽

Vol 46 ◽

pp. 414-415

Author(s):

A. Tanaka ◽

M. Yamaguchi ◽

T. Hirano

Keyword(s):

Power Supply ◽

Plasma Polymerization ◽

Vacuum Chamber ◽

Complex Surface ◽

Replica Method ◽

Metal Extraction ◽

High Voltage Power Supply ◽

Negative Glow ◽

Hydrocarbon Gas ◽

Hydrocarbon Molecules

The plasma polymerization replica method and its apparatus have been devised by Tanaka (1-3). We have published several reports on its application: surface replicas of biological and inorganic specimens, replicas of freeze-fractured tissues and metal-extraction replicas with immunocytochemical markers.The apparatus for plasma polymerization consists of a high voltage power supply, a vacuum chamber containing a hydrocarbon gas (naphthalene, methane, ethylene), and electrodes of an anode disk and a cathode of the specimen base. The surface replication by plasma polymerization in negative glow phase on the cathode was carried out by gassing at 0.05-0.1 Torr and glow discharging at 1.5-3 kV D.C. Ionized hydrocarbon molecules diffused into complex surface configurations and deposited as a three-dimensionally polymerized film of 1050 nm in thickness.The resulting film on the complex surface had uniform thickness and showed no granular texture. Since the film was chemically inert, resistant to heat and mecanically strong, it could be treated with almost any organic or inorganic solvents.

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Three-Dimensional Immunoelectron Microscopy of Yeast Cells by a New High-Resolution Replica Method

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119594 ◽

1985 ◽

Vol 43 ◽

pp. 562-563

Author(s):

Hirano T. ◽

M. Yamaguchi ◽

M. Hayashi ◽

Y. Sekiguchi ◽

A. Tanaka

Keyword(s):

High Resolution ◽

Plasma Polymerization ◽

Three Dimensional ◽

Freeze Fracture ◽

Replica Method ◽

Yeast Cells ◽

Dynamic Aspect ◽

Replica Technique ◽

Gaseous Hydrocarbon ◽

Transmission Electron

A plasma polymerization film replica method is a new high resolution replica technique devised by Tanaka et al. in 1978. It has been developed for investigation of the three dimensional ultrastructure in biological or nonbiological specimens with the transmission electron microscope. This method is based on direct observation of the single-stage replica film, which was obtained by directly coating on the specimen surface. A plasma polymerization film was deposited by gaseous hydrocarbon monomer in a glow discharge.The present study further developed the freeze fracture method by means of a plasma polymerization film produces a three dimensional replica of chemically untreated cells and provides a clear evidence of fine structure of the yeast plasma membrane, especially the dynamic aspect of the structure of invagination (Figure 1).

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