THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: VI. OXIDATION–REDUCTION CHANGES IN WHEAT LEAF SAP CAUSED BY RUST INFECTION

1960 ◽  
Vol 38 (3) ◽  
pp. 399-407 ◽  
Author(s):  
Rudolf Kaul ◽  
Michael Shaw
Keyword(s):  
Short Circuit ◽  
Redox Mediators ◽  
Rust Infection ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Wheat Leaf ◽  
Host Parasite ◽  
Different Levels ◽  
Reduced State

Extracts of healthy and rusted leaves of Little Club and Khapli wheats were made under anaerobic conditions. Oxidation–reduction potentials in the extracts were measured at two different levels both in the presence and in the absence of both methylene blue and riboflavin as redox mediators. At the lower level (i.e. in the absence of mediators) a reversible rise in potential was noted during the course of rust infection on Little Club; with Khapli the rise was similar but was not reversed. The response to rust infection of resistant and susceptible plants was also reflected in characteristic changes in the average potentials at higher levels (i.e. in the presence of mediators). After infection the oxidation–reduction balance of susceptible tissue was reorganized by the introduction of new systems which were found in the reduced state only. After infection the oxidation–reduction potential of resistant tissue was only poorly poised as indicated by a rise in the average potentials and as demonstrated by oxidation– reduction titrations.The results are discussed and the possibility is considered that a rust-induced catalyst may “short circuit” the chain of hydrogen transport, thus initiating all the observed redox changes.

37. Studies in Cheddar Cheese: I. The Oxidation-Reduction Potentials of Ripening Cheddar Cheese

1932 ◽  
Vol 3 (3) ◽  
pp. 241-253 ◽  
Author(s):  
John Gilbert Davis
Keyword(s):  
Reduction Potential ◽  
Cheddar Cheese ◽  
Mean Values ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Different Levels

1. A method is described for following the intensity of reduction (or oxidation-reduction potential) at different levels in the interior of ripening Cheddar cheese.2. Variations in this potential throughout the course of ripening are described and mean values assessed.3. Cheese are shown to be not homogeneous throughout their mass; outer zones of more highly oxidised condition exist near the surface of the cheese and round cracks and borings. The depth of these zones increases with the age of the cheese.4. The values obtained can be correlated with the known bacteriological data for Cheddar cheese.5. The significance of the data obtained in relation to cheese faults is discussed.

scholarly journals OXIDATION-REDUCTION POTENTIALS AND THE POSSIBLE RESPIRATORY SIGNIFICANCE OF THE PIGMENT OF THE NUDIBRANCH CHROMODORIS ZEBRA

1930 ◽  
Vol 13 (3) ◽  
pp. 349-359 ◽  
Author(s):  
Paul W. Preisler
Keyword(s):  
Oxygen Transfer ◽  
Reduction Potential ◽  
Product Form ◽  
Reversible System ◽  
Purple Pigment ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Valence Change ◽  
Potential Methods

1. Oxidation-reduction potential methods have been applied to a study of the blue-purple pigment present in solution in the blood and in the tissue cells of the nudibranch Chromodoris zebra. 2. The blue-purple pigment and its yellow reduction product form a reversible system whose Eo' = x0.102 volts at pH 7.0 and whose valence change from oxidant to reductant appears to be one. 3. The system is unlike oxyhemoglobin-hemoglobin in the mode of oxygen transfer. Its rôle as a possible respiratory material is discussed.

Apparatus and techniques for the measurement of oxidation-reduction potentials, pH and oxygen tension in vivo

1957 ◽  
Vol 146 (923) ◽  
pp. 289-297 ◽  
Keyword(s):  
Oxygen Tension ◽  
Reduction Potential ◽  
Model Experiments ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Small Voltage

In order to follow the changes which occur in tumours during treatment with radiation, and the effects of radiosensitizing or radioprotecting drugs, apparatus and techniques have been developed to record automatically changes of oxidation-reduction potential on eight different electrodes. Simultaneous records of pH and oxygen tension changes were used as controls in some experiments. The changes of oxygen tension were followed by applying a known small voltage to one electrode and measuring the current which flowed. Calibration of oxygen-tension measurements was attempted by the use of model experiments.

scholarly journals WHAT IS ORP AND WHAT YOU SHOULD KNOW ABOUT IT

2014 ◽  
Vol 11 (1) ◽  
pp. 32-38
Author(s):  
Irena Čerčikienė ◽  
Jolanta Jurkevičiūtė ◽  
Dalė Židonytė
Keyword(s):  
Mineral Water ◽  
Reduction Potential ◽  
The Body ◽  
Acid Base Balance ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Bactericidal Properties ◽  
Base Balance ◽  
Two Parameters

Currently in mass media and advertising we often hear about the importance of living water in human daily life. You may ask, “What is living water? Is it really living? Is it alkaline?” The importance of water to the human body can be determined by the oxidation – reduction potential (ORP) – a parameter characterizing the ability of the matter to give and connect electrons, which can be measured not only in water but also in food and in the air. Solutions, which contain negative ORP value (e.g. alkaline ionized water), are characterized by reduction features and have the ability to neutralize free radicals and stop the signs of aging. Solutions containing positive ORP value have oxidative properties, which are typical for the alkaline ionized water, which has bactericidal properties. Thus, the ionized water has two parameters: its pH and oxidation - reduction potential, which make it different from the ordinary water. Ionized water, like the raw unprocessed food, is considered to be the body rejuvenating agent. The basic principle, which should be followed, is to consume food and water, which contain the lowest possible negative ORP. The authors provide the research results, although, it is known that most of water tests are difficult to reproduce due to objective reasons, as water, with the gases dissolved in it, represents a very complicated balanced oxidation – reduction system. Oxidation reduction potentials of drinking and mineral water, as well as other beverages, have been studied, and the dynamics of these parameters in ionized water over time has been determined. Key words: acid-base balance, pH index, oxidation – reduction potential (ORP), ionized water, alkaline water, living water, catholyte, acidic water, inanimate water, anolyte.

scholarly journals Analytical Characterisation of Original Emulsion for Cosmetic Use

2019 ◽  
Vol 70 (3) ◽  
pp. 749-752
Author(s):  
Gabriela Stanciu ◽  
Adina-Ioana Oancea ◽  
Elena Oancea ◽  
Elisabeta Chirila
Keyword(s):  
Chemical Properties ◽  
Mentha Piperita ◽  
Beneficial Effects ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Acidity Index ◽  
Plant Mixture ◽  
Lavandula Officinalis ◽  
Physical And Chemical

The aim of the paper is to characterize an original emulsion containing a mixture of plant macerates and essences. Next the wild and/or garden plants, namely Abies sp. (leaves), Crataegus monogyna (flowers), Hypericum perforatum (flowers), Lavandula angustifolia (flowers), Lavandula officinalis (flowers), Lilium sp. (flowers), Melissa officinalis (flowers), Mentha silvestris (leaves and flowers), Mentha piperita (leaves and flowers), Origanum vulgare (leaf blooms and flowers), Pinus silvestris (buds), Populus nigra (buds) and Thymus serpillum (flowers) have been processed to prepare the studied emulsion. Some of the emulsion ingredients as the essential oils of single plant and plant mixture, or the lily flowers macerate together with the final product have been analyzed. The measurements of physical and chemical properties (refractive index, density, pH, oxidation-reduction potential, acidity index, peroxide index and iodine index) led to interesting results that could explain the curative effects on skin. The beneficial effects of new emulsion are due to the bioactive compounds that penetrate deep into the tissue and ensure regeneration. The obtained results confirm our previous findings concerning the opportunity of measurements of oxidation/reduction potentials for cosmetic mixtures regarding the antioxidant activity description.

scholarly journals Performance Degradation of Dye-Sensitized Solar Cells Induced by Electrolytes

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Ru-Yuan Yang ◽  
Huang-Yu Chen ◽  
Fu-Der Lai
Keyword(s):  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Dye Sensitized ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Sensitized Solar Cells ◽  
Open Circuit Photovoltage

We investigated the change of the electric characteristics in dye-sensitized solar cell (DSSC) when the electrolyte has been injected and measured initially and lately for a period of time. It was found that the short-circuit current density decreased from 9.799 mA/cm2to 7.056 mA/cm2and the fill factor increased from 0.406 to 0.559 when the cell had stood for an hour, while the open-circuit photovoltage did not change due to fixed difference between the Fermi level of TiO2and the oxidation-reduction potential of electrolyte. The results can be explained by using the variation of the series resistance in the equivalent circuit of the DSSC.

Induced changes in oxidation-reduction potentials, pH, and oxygen tension in the intact lactating mammary gland

1957 ◽  
Vol 146 (924) ◽  
pp. 400-415 ◽  
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Oxygen Tension ◽  
Reduction Potential ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Lactating Mammary Gland ◽  
Other Substances

This work was undertaken to find if a study of oxidation-reduction potentials, pH and oxygen tension would yield information concerning physiological changes induced in lactating mammary glands of rats and rabbits by hormones and other substances. Breathing oxygen at atmospheric pressure caused a rapid rise in oxygen tension in lactating mammary gland, and a small, slower rise of oxidation-reduction potential. Breathing nitrogen had the opposite effect. Oxytocin caused a rapid temporary fall of oxidation-reduction potential, synchronous with milk ejection. With adrenaline the response was more rapid and the oxygen tension fell to zero, to recover within 2 min. Vasopressin produced a slower fall and recovery. Insulin (35 μ g/kg) caused a preliminary rise of oxidation-reduction potential, followed by a fall lasting 1 h. The fall could be largely abolished by glucose. The synthetic oestrogen doisynolic acid caused a triphasic response in the oxidation-reduction potentials and increased oxygen tension in the gland. It reduced, but did not abolish, the changes due to insulin. Desoxycorticosterone glucoside caused a slow rise of oxidation-reduction potential, but did not alter the response to insulin. Intermedin caused a small rise of oxidation-reduction potential. The effects produced by commercial ACTH may have been due to the oxytocin and intermedin present. Growth hormone induced a small diphasic change in the oxidation-reduction potentials. The radiosensitizers tetrasodium 2-methyl-1:4-naphthohydroquinone diphosphate and tetrasodium trimethyl-hydroquinone diphosphate produced marked falls of oxidation-reduction potential even with small doses, without change of oxygen tension. Intravenous potassium ferricyanide appeared to liberate oxygen from haemoglobin in vivo . The pH of mammary gland became slightly more acid after breathing oxygen, and also in the preliminary response to insulin, glucose, doisynolic acid and desoxycorticosterone glucoside; and after oxytocin, vasopressin and growth hormone.

scholarly journals The hydrogen-ion concentration and oxidation-reduction potential of the cell-interior before and after fertilisation and cleavage: A micro-injection study on marine eggs

1926 ◽  
Vol 99 (695) ◽  
pp. 173-199 ◽  
Keyword(s):  
Single Cells ◽  
Biological Data ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Before And After ◽  
Egg Membrane ◽  
The Moment

In our previous communications on this subject we have described experiments dealing with the micro-injection of indicators into single cells. In the conclusion to our paper (10 a ) on the p H. and r H of the Amœba, we said, “It is hoped that other biological data will soon be available . . . such problems as the . . . oxidation-reduction potentials of egg-cells before and after fertilisation at once present themselves.” The present paper is devoted to these problems. Warburg (17) and Meyerhof (8), and afterwards other workers, observed an enormous increase in the oxygen-consumption of the egg to take place on fertilisation. Shearer (12) found that this occurred at the moment of contact of the spermatozoon with the egg membrane. In view of the fact that the increase was about 2000 per cent., it was clearly a matter of great interest to determine whether the r H changed at the same time. We have attempted to follow the changes in r H by micro-injection experiments and by staining. The two methods failed to give concordant results for reasons which are discussed in the text.

The physiology of host–parasite relations. XIX. Further observations on nucleoprotein changes in wheat leaf nuclei during rust infection

1968 ◽  
Vol 46 (1) ◽  
pp. 11-16 ◽  
Author(s):  
P. K. Bhattacharya ◽  
Michael Shaw ◽  
J. M. Naylor
Keyword(s):  
Stem Rust ◽  
Rust Fungus ◽  
Puccinia Graminis ◽  
Mesophyll Cells ◽  
Rust Infection ◽  
Puccinia Graminis Tritici ◽  
Wheat Leaf ◽  
Host Parasite

Cytophotometric measurements of DNA (Feulgen) and protein-bound lysine and arginine (fluorodinitrobenzene-Sakaguchi) were made on nuclei in mesophyll cells of infected and uninfected leaves of Little Club wheat at intervals of 2 to 4 days up to 13 days after inoculation with uredospores of race 15B of the stem rust fungus (Puccinia graminis tritici Erikss. and Henn.). No change in host DNA was found within 6 days after inoculation, but there were marked decreases in protein-bound lysine and arginine as early as 2 days after inoculation. The DNA/lysine and DNA/arginine ratios were higher in rust-affected host nuclei, but infection did not alter the ratio of protein-bound lysine to arginine. In another series of measurements it was shown that rust infection caused striking increases in the volume and the RNA and protein contents of host nucleoli. These changes persisted even in advanced infections.All the results are consistent with our earlier observations and indicate that profound changes in nuclear metabolism are induced by infection with the rust fungus.

scholarly journals THE OXIDATION-REDUCTION POTENTIAL OF THE LUCIFERIN-OXYLUCIFERIN SYSTEM

1927 ◽  
Vol 10 (3) ◽  
pp. 385-393 ◽  
Author(s):  
E. Newton Harvey
Keyword(s):  
Dissolved Oxygen ◽  
Reduction Potential ◽  
Water Solution ◽  
Considerable Reduction ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Apparent Reduction ◽  
Reduction And Oxidation

The oxidation-reduction potential of the Cypridina luciferin-oxyluciferin system determined by a method of "bracketing" lies somewhere between that of anthraquinone 2-6-di Na sulfonate (Eo' at pH of 7.7 = –.22) which reduces luciferin, and quinhydrone (Eo' at pH of 7.7 = +.24), which oxidizes luciferin. Systems having an Eo' value between –.22 and +.24 volt neither reduce oxyluciferin nor oxidize luciferin. If the luciferin-oxyluciferin system were truly reversible considerable reduction and oxidation should occur between –.22 and +.24. The system appears to be an irreversible one, with both "apparent oxidation" and "apparent reduction potentials" in Conant's sense. Hydrosulfites, sulfides, CrCl2, TiCl3, and nascent hydrogen reduce oxyluciferin readily in absence of oxygen but without luminescence. Luminescence only appears in water solution if luciferin is oxidized by dissolved oxygen in presence of luciferase. Rapid oxidation of luciferin by oxygen without luciferase or oxidation by K3Fe(CN)6 in presence of luciferase but without oxygen never gives luminescence.

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