scholarly journals Electron Microscopic Studies of Spermatozoa I. The Morphology of the Spermatozoon of the Common Domestic Fowl (Gallus Domesticus)

1949 ◽  
Vol 2 (3) ◽  
pp. 271 ◽  
Author(s):  
GW Grigg ◽  
AJ Hodge
Keyword(s):  
Electron Microscope ◽  
Light Microscopy ◽  
Domestic Fowl ◽  
Gallus Domesticus ◽  
Distilled Water ◽  
Electron Microscopic ◽  
Enzymic Digestion ◽  
Microscopic Studies ◽  
The Common

The morphology of the fowl spermatozoon, as revealed by use of the electron microscope and such techniques as partittl enzymic digestion and disruption with distilled water, is described in detail, and compared with that observable by light microscopy.

scholarly journals Electron Microscopic Studies of Spermatozoa II. the Morphology of the Human Spermatozoon

1949 ◽  
Vol 2 (4) ◽  
pp. 368 ◽  
Author(s):  
AJ Hodge
Keyword(s):  
Electron Microscope ◽  
Sperm Motility ◽  
Clear Picture ◽  
Human Spermatozoon ◽  
Electron Microscopic ◽  
Enzymic Digestion ◽  
Microscopic Studies

Suitable washing techniques, which do not appreciably affect sperm motility, and enzymic digestion, have made it possible to give a clear picture of the finer structures in the human spermatozoon, using the electron microscope.

scholarly journals An Electron Microscope Study of Snow Crystal Nuclei

1953 ◽  
Vol 2 (13) ◽  
pp. 176-180
Author(s):  
Ukichiro Nakaya
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Condensation Nuclei ◽  
Electron Microscopic ◽  
Carbon Particles ◽  
Snow Crystal ◽  
Microscopic Studies ◽  
Snow Crystals ◽  
Micro Organisms ◽  
Collodion Film

AbstractSnow crystals were received on the collodion film of the holder of an electron microscope, and made to sublimate without melting. These specimens were investigated under an electron microscope. One solid nucleus was always observed in the central portion of a snow crystal. These centre nuclei were of sizes between 0.5 and 8μ. Most of them were presumed to be kaolin, clay or carbon particles; some were considered to be micro-organisms. In the other parts of snow crystals numerous smaller nuclei were observed, whose dimensions were of the order of those of condensation nuclei. These condensation nuclei were found to be of two kinds, the larger ones most frequently having a diameter of about 0.15μ, the smaller ones of about 0.05μ. A new theory was proposed from the data of the electron microscopic studies and those of the conditions of formation of snow crystals. In this theory it is proposed that minute water droplets of 1μor so play an important rôls in the process of snow crystal growth.

Electron microscopic observations of the envelopes of isolated algal packets of Azolla

1991 ◽  
Vol 69 (7) ◽  
pp. 1418-1419 ◽  
Author(s):  
Eiji Uheda ◽  
Shunji Kitoh
Keyword(s):  
Electron Microscope ◽  
Nitric Acid ◽  
Sodium Hydroxide ◽  
Key Words ◽  
Layer Structure ◽  
Sodium Dodecylsulfate ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
20 Nm

The envelopes of isolated algal packets from cyanobiont-containing and cyanobiont-free Azolla were examined with the electron microscope. Both types of envelope were 10–20 nm thick and composed of three layers. The three-layer structure was also observed when algal packets were treated with cellulase, pectinase, lipase, protease, sodium hydroxide, nitric acid, or sodium dodecylsulfate. Thus, the envelopes do not appear to be membrane-like in nature and the presence and ultrastructure of the envelopes are not affected by cyanobiont filaments. Key words: algal packet, cyanobiont-free Azolla, Azolla, electron microscopic studies, envelope.

Electron Microscopic Studies of Fillers in Rubber. III. Effect of Milling on the Dispersion of Fillers

1956 ◽  
Vol 29 (3) ◽  
pp. 1003-1010 ◽  
Author(s):  
Eiji Suito ◽  
Masafumi Arakawa ◽  
Hiroshi Hasegawa ◽  
Yonemasa Furusawa
Keyword(s):  
Electron Microscope ◽  
Marked Effect ◽  
The State ◽  
Replica Method ◽  
Interesting Problem ◽  
Electron Microscopic ◽  
Vulcanized Rubber ◽  
Microscopic Studies ◽  
Filler Particles ◽  
The Relationship

Abstract In the study of types of fillers which have a marked effect on the properties of rubber, information as to how the filler particles are dispersed in rubber is a prerequisite. The authors have already reported on the state of dispersion of various fillers in vulcanized rubber, observed under an electron microscope by the replica method. How the dispersion of these fillers affects the properties of rubber is an interesting problem. Since, in the earlier work, filler particles were observed to orient themselves in certain directions, in this report the relationship between the state of dispersion observed under an electron microscope of filler particles in rubber milled in different ways and the resulting characteristics of the mixtures were examined.

FINE STRUCTURE OF NUCLEOLI AND RNA-CONTAINING CHROMOSOME REGIONS OF SALIVARY GLAND CHROMOSOMES OF CHIRONOMIDS AND THEIR INTERRELATIONSHIP

1964 ◽  
Vol 42 (6) ◽  
pp. 1147-1155 ◽  
Author(s):  
V. I. Kalnins ◽  
H. F. Stich ◽  
S. A. Bencosme
Keyword(s):  
Fine Structure ◽  
Salivary Gland ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Messenger Rna ◽  
Balbiani Ring ◽  
Electron Microscopic ◽  
Chironomid Species ◽  
Balbiani Rings ◽  
Chromosome Regions

Electron microscope studies of salivary gland nuclei of four chironomid species have shown that the RNA-containing chromosome regions and associated structures, which by light microscopy exhibit a great variety of structures such as bands, granules, micronucleoli, nucleoli, puffs, and Balbiani rings, consist of only few basic units: pars amorpha, nucleolonema, and Balbiani ring granules. The fine structure of the nucleoli and spherical micronucleoli located at various chromosome regions appears to be identical, consisting of pars amorpha, which contains fibers of varying diameters, and strands of nucleolonema composed of fibers and ribosome-like granules. The arrangement of pars amorpha and nucleolonema of nucleoli and spherical micronucleoli follows a consistent pattern. Chromosome fibers are closely associated with pars amorpha, whereas strands of nucleolonema border only the surfaces of pars amorpha. Balbiani ring granules, which have a diameter of 300 Å to 500 Å and are characterized by a particular structure, accumulate in Balbiani rings, in many chromosome regions, and in nuclear sap. In the Balbiani ring these granules seem to be attached to 100 Å chromosome fibers. They are absent in nucleoli and micronucleoli. The possible correlation between our electron microscopic observations and the present-day concept of ribosomal and messenger RNA production is discussed.

Electron microscope study on the glial filaments of astrocytes in the rat brain

1978 ◽  
Vol 36 (2) ◽  
pp. 618-619
Author(s):  
S. Mori ◽  
K. Furukawa ◽  
H. Abe
Keyword(s):  
Body Weight ◽  
Electron Microscope ◽  
Glial Cells ◽  
Microscope Study ◽  
Phosphate Buffer ◽  
Electron Microscope Study ◽  
Gold Chloride ◽  
Electron Microscopic ◽  
New Knowledge ◽  
Microscopic Studies

With the electron microscope, it was demonstrated that the glial filaments existed in astrocytes and could be impregnated by Cajal's gold chloride sublimate solution. By this conspicuous structure of glial filaments, thus, the astrocytes have long been differentiated from other glial cells from the classical light microscopic studies till the recent electron microscopic observations. Further investigations could add the new knowledge on this important component of glial cells in this laboratory that the actin- like filaments might be contained among the glial filaments. It will be shown in this report that glial filaments of astrocytes are consisted of the heterogenous groups of filaments, and some of them can bind with the heavy meromyosins (HMM).Normal rats (about 120 g body weight) were anesthetized with Nembutal and fixed by perfusion through the heart for 30 minutes with the fixative. This fluid was consisted of 3 % glutaraldehyde, 2 % paraformaldehyde, 4 % sucrose and 0. 5 mM CaCl2 in 0. 1 M phosphate buffer at PH 7. 4.

Electron microscopy of spermatocytes previously studied in life: methods and some observations on micromanipulated chromosomes

1979 ◽  
Vol 35 (1) ◽  
pp. 87-104
Author(s):  
R.B. Nicklas ◽  
B.R. Brinkley ◽  
D.A. Pepper ◽  
D.F. Kubai ◽  
G.K. Rickards
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Target Cell ◽  
Living Cell ◽  
Chromosome Movement ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Direction Of Movement ◽  
Spindle Microtubules ◽  
Future Work

A new method is offered for combined living cell and electron-microscopic studies of spermatocytes (or other cells) which normally do not adhere to glass. The key step is micro-injection of glutaraldehyde near the target cell whenever desired during observation in life. Fixation begins and simultaneously the cell is stuck very firmly to the underlying coverslip. The method is easy and reliable: cells are almost never lost and are well preserved, except for membranes. The application of the method is illustrated by studies of micromanipulated grasshopper spermatocytes. A chromosome was detached from the spindle and placed in the cytoplasm. Before or after the beginning of chromosome movement back toward the spindle, the cell was fixed, sectioned and the manipulated chromosome observed in the electron microscope. If the detached chromosome had not moved by the time of fixation, no or only one or two microtubules were seen at its kinetochore, but if movement had occurred, a few microtubules were always present. The arrangement of these microtubules corresponded to the direction of movement, but they commonly were at an unusual angle relative to the kinetochore. The origin and role in chromosome movement of the microtubules seen near moving chromosomes far from the spindle is not yet established, but a speculation is offered. A goal for future work is the detailed analysis of the microtubules associated with individual moving chromosomes. Such an analysis is feasible because the moving chromosome is far removed from the confusing mass of spindle microtubules, and its value is enhanced because the direction of movement at the time of fixation is known.

Sign in / Sign up

Export Citation Format

Share Document