The hexosamine content of leaves

1974 ◽  
Vol 52 (9) ◽  
pp. 2111-2113 ◽  
Author(s):  
David Racusen ◽  
Murray Foote

Leaves of 20 species contained both polymer-bound and 80%-acetone-soluble forms of hexosamine. Similar amounts of polymer-bound hexosamine (about 1.9 μg/mg protein) were found in all the leaves, suggesting that it may be an essential element of membrane structure.

Author(s):  
Robert M. Glaeser ◽  
David W. Deamer

In the investigation of the molecular organization of cell membranes it is often supposed that lipid molecules are arranged in a bimolecular film. X-ray diffraction data obtained in a direction perpendicular to the plane of suitably layered membrane systems have generally been interpreted in accord with such a model of the membrane structure. The present studies were begun in order to determine whether selected area electron diffraction would provide a tool of sufficient sensitivity to permit investigation of the degree of intermolecular order within lipid films. The ultimate objective would then be to apply the method to single fragments of cell membrane material in order to obtain data complementary to the transverse data obtainable by x-ray diffraction.


Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.


Author(s):  
E. L. Vigil ◽  
E. F. Erbe

In cotton seeds the radicle has 12% moisture content which makes it possible to prepare freeze-fracture replicas without fixation or cryoprotection. For this study we have examined replicas of unfixed radicle tissue fractured at room temperature to obtain data on organelle and membrane structure.Excised radicles from seeds of cotton (Gossyplum hirsutum L. M-8) were fractured at room temperature along the longitudinal axis. The fracture was initiated by spliting the basal end of the excised radicle with a razor. This procedure produced a fracture through the tissue along an unknown fracture plane. The warm fractured radicle halves were placed on a thin film of 100% glycerol on a flat brass cap with fracture surface up. The cap was rapidly plunged into liquid nitrogen and transferred to a freeze- etch unit. The sample was etched for 3 min at -95°C to remove any condensed water vapor and then cooled to -150°C for platinum/carbon evaporation.


Author(s):  
M. H. Chen ◽  
C. Hiruki

Wheat spot mosaic disease was first discovered in southern Alberta, Canada, in 1956. A hitherto unidentified disease-causing agent, transmitted by the eriophyid mite, caused chlorosis, stunting and finally severe necrosis resulting in the death of the affected plants. Double membrane-bound bodies (DMBB), 0.1-0.2 μm in diameter were found to be associated with the disease.Young tissues of leaf and root from 4-wk-old infected wheat plants were fixed, dehydrated, and embedded in Spurr’s resin. Serial sections were collected on slot copper grids and stained. The thin sections were then examined with a Hitachi H-7000 TEM at 75 kV. The membrane structure of the DMBBs was studied by numbering them individually and tracing along the sections to see any physical connection with endoplasmic reticulum (ER) membranes. For high resolution scanning EM, a modification of Tanaka’s method was used. The specimens were examined with a Hitachi Model S-570 SEM in its high resolution mode at 20 kV.


2019 ◽  
Vol 12 (1) ◽  
pp. 77-87
Author(s):  
György Kovács ◽  
Rabab Benotsmane ◽  
László Dudás

Recent tendencies – such as the life-cycles of products are shorter while consumers require more complex and more unique final products – poses many challenges to the production. The industrial sector is going through a paradigm shift. The traditional centrally controlled production processes will be replaced by decentralized control, which is built on the self-regulating ability of intelligent machines, products and workpieces that communicate with each other continuously. This new paradigm known as Industry 4.0. This conception is the introduction of digital network-linked intelligent systems, in which machines and products will communicate to one another in order to establish smart factories in which self-regulating production will be established. In this article, at first the essence, main goals and basic elements of Industry 4.0 conception is described. After it the autonomous systems are introduced which are based on multi agent systems. These systems include the collaborating robots via artificial intelligence which is an essential element of Industry 4.0.


2020 ◽  
Vol 26 (3) ◽  
pp. 261-280
Author(s):  
Rhoderick John Suarez Abellanosa

The declaration of enhanced community quarantine (ECQ) in various provinces and cities in the Philippines did not impede the Catholic Church from celebrating its sacraments and popular devotions. Mired with poverty and various forms of economic and social limitations, the presence of God for Filipinos is an essential element in moving forward and surviving in a time of pandemic. Predominantly Roman Catholic in religious affiliation, seeking the face of God has been part of Filipinos' lives whenever a serious disaster would strike. This essay presents how the clergy, religious and lay communities in the Philippines have innovatively and creatively sustained treasured religious celebrations as a sign of communion and an expression of faith. In addition to online Eucharistic celebrations that are more of a privilege for some, culturally contextualised efforts were made during the Lenten Season and even on Sundays after Easter. This endeavour ends with a reflection on the Church as the sacrament of God in a time of pandemic. Pushed back to their homes, deprived of life's basic necessities and facing threats of social instability, unemployment and hunger, Filipinos through their innovative celebrations find in their communion with their Church the very presence of God acting significantly in their lives.


1961 ◽  
Vol 36 (2) ◽  
pp. 197-211 ◽  
Author(s):  
lb Lorenzen

ABSTRACT Biochemical and histological changes in the aortic wall of rabbits were demonstrated following injection of epinephrine and l-thyroxine during 2 weeks. The widespread gross and microscopic changes were accompanied by an increase in hexosamine content and uptake of 35S labeled sodium sulphate, and an increased calcium content, whereas the collagen content, assessed by determination of hydroxyproline, was reduced. Comparison with the effect of epinephrine injections alone showed that thyroxine intensified the damaging effect of epinephrine on the vessel wall and induced more pronounced mucopolysaccharide changes in the aortic wall, presumably acting as a link in the healing processes.


1962 ◽  
Vol 41 (3) ◽  
pp. 474-480 ◽  
Author(s):  
Otto Wegelius ◽  
E. J. Jokinen

ABSTRACT In all previous investigations on experimental exophthalmos, heterologous thyrotrophic pituitary extracts have been used. These protein hormones stimulate antihormone formation in the test animals. Cortisone has been reported to effectively block antibody formation. In addition, it has been shown to potentiate TSH-induced exophthalmos in guinea-pigs. With rabbits as test animals, the hexosamine content of the orbital tissues was determined and used as an index of exophthalmos development and at the same time the antibody titres in the sera were followed. TSH injections for six weeks led to a highly significant accumulation of hexosamine in the retrobulbar connective tissue and in the extraocular muscles, i. e. an increase of up to 400% as compared with the control animals. At the same time a significant rise in antihormonal titres was detectable in the sera. Concomitant treatment with cortisone brought about an equal or higher accumulation of hexosamine but significantly lower antibody titres. The known opposite peripheral actions of TSH and cortisone can be reconciled with the synergy in producing experimental exophthalmos by attributing the synergetic action of cortisone to the blocking of antihormone formation. If less antihormones are produced, the effect of TSH is enhanced. Our experiments do not provide direct proof for this hypothesis. High hexosamine values in the orbit and low antihormone titres in the serum are, however, concomitant phenomena.


Think India ◽  
2019 ◽  
Vol 22 (3) ◽  
pp. 1751-1757
Author(s):  
Rohith Raja M ◽  
Ida David

Customers hold the key role in determining the market of any material. The demand and requirements of the customers are taken into account while the manufacturers produce any product. Mobile phones, being an essential element in today’s world, occupy a large market in today’s business world. Customer satisfaction is the prime motive of the manufacturing companies. Based on a survey conducted, we study the current trend of phone purchase in India and thus analyze the customer’s responses towards different brands and their products. The results depict which brands satisfy the customer requirements.


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