A NIPAM-Zwitterion Copolymer: Rheological Interpretation of the Specific Ion Effect on the LCST

2014 ◽  
Vol 215 (21) ◽  
pp. 2125-2125 ◽  
Author(s):  
Francis O. Obiweluozor ◽  
Amin GhavamiNejad ◽  
Saud Hashmi ◽  
Mohammad Vatankhah-Varnoosfaderani ◽  
Florian J. Stadler
Keyword(s):  
Specific Ion Effect

Effects of some salts and sodicity on the growth of a Rhizobium leguminosarum bv. viceae strain isolated from a salt-affected soil

2001 ◽  
Vol 47 (9) ◽  
pp. 807-812 ◽  
Author(s):  
M Y Faituri ◽  
Y E El-Mahi ◽  
G A El-Hassan
Keyword(s):  
Rhizobium Leguminosarum ◽  
Harmful Effect ◽  
Negative Effects ◽  
Salt Affected Soil ◽  
Retarded Growth ◽  
Cultural Medium ◽  
Yeast Extract Mannitol ◽  
Salinity Levels ◽  
Specific Ion Effect ◽  
Effect On Growth

The effects of sodium (Na+), calcium (Ca2+), magnesium (Mg2+), and boron (B) concentrations and sodicity, as measured by the sodium adsorption ratio (SAR), on the growth of a Rhizobium leguminosarum bv. viceae strain isolated from a salt-affected soil were studied. The rate of growth was measured in a yeast extract - mannitol broth, amended with salts having electrical conductivity (EC) of 4, 8, and 16 dS·m-1. Each salinity level was prepared to achieve SAR values of 10, 20, and 30 with or without graded B concentrations of 0.5, 1, 3, and 5 mg·L-1. We found that salinity levels equal to or more than 8 dS·m-1 had negative effects on Rhizobium growth during the first days of incubation, but the effects became less pronounced after 1 week. Na+ concentrations of more than 1.1 g·L-1 retarded growth, especially at high SAR values (i.e., at low Ca2+ concentrations). The retardation of growth increased with increases in EC up to 16 dS·m-1, at all sodicity levels. Mg2+ added together with Na+ or with Ca2+ + Na+ affected growth more negatively than Ca2+ + Na+ alone. The effect of Mg2+ became more pronounced with increased salinities and sodicities. It was concluded that EC of more than 4 dS·m-1 retarded growth of Rhizobium, but only at high sodicity levels. The relative specific ion effect on growth was in the order Na+ < Ca2+ < Mg2+. The harmful effect of Mg2+ on this strain was accentuated by adding Ca2+ to the cultural medium. When SAR increased from 10 to 30, Na+ had no clear effect on growth, irrespective of the accompanied cations, i.e, Ca2+, Mg2+, or Ca2+ + Mg2+. Growth was reduced by B concentrations as low as 0.5 mg·L-1, and the B effect was enhanced by increased salinity.Key words: Rhizobium leguminosarum bv. viceae, salinity, sodicity, boron.

Specific ion effect as a probable cause of growth inhibition under saline conditions

1979 ◽  
Vol 52 (3) ◽  
pp. 457-459 ◽  
Author(s):  
Ashok K. Shukla ◽  
B. D. Baijal ◽  
G. K. Chaturvedi
Keyword(s):  
Growth Inhibition ◽  
Specific Ion Effect

Dramatic Specific-Ion Effect in Supramolecular Hydrogels

2012 ◽  
Vol 18 (37) ◽  
pp. 11723-11731 ◽  
Author(s):  
Sangita Roy ◽  
Nadeem Javid ◽  
Pim W. J. M. Frederix ◽  
Dimitrios A. Lamprou ◽  
Andrew J. Urquhart ◽  
...  
Keyword(s):  
Specific Ion Effect

scholarly journals How Salinity Damages Citrus: Osmotic Effects and Specific Ion Toxicities

2005 ◽  
Vol 15 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Louise Ferguson ◽  
Steven R. Grattan
Keyword(s):  
Soil Solution ◽  
Woody Plants ◽  
Total Concentration ◽  
Citrus Fruit ◽  
Nutrient Status ◽  
Threshold Concentration ◽  
Ion Toxicity ◽  
Direct Injury ◽  
Specific Ion Effect ◽  
Osmotic Effects

There are two ways salinity can damage citrus: direct injury due to specific ions, and osmotic effects. Specific ion toxicities are due to accumulation of sodium, chloride, and/or boron in the tissue to damaging levels. The damage is visible as foliar chlorosis and necrosis and, if severe enough, will affect orchard productivity. These ion accumulations occur in two ways. The first, more controllable and less frequent method, is direct foliar uptake. Avoiding irrigation methods that wet the foliage can easily eliminate this form of specific ion damage. The second way specific ion toxicity can occur is via root uptake. Certain varieties or rootstocks are better able to exclude the uptake and translocation of these potentially damaging ions to the shoot and are more tolerant of salinity. The effect of specific ions, singly and in combination, on plant nutrient status can also be considered a specific ion effect. The second way salinity damages citrus is osmotic effects. Osmotic effects are caused not by specific ions but by the total concentration of salt in the soil solution produced by the combination of soil salinity, irrigation water quality, and fertilization. Most plants have a threshold concentration value above which yields decline. The arid climates that produce high quality fresh citrus fruit are also the climates that exacerbate the salt concentration in soil solution that produces the osmotic effects. Osmotic effects can be slow, subtle, and often indistinguishable from water stress. With the exception of periodic leaching, it is difficult to control osmotic effects and the cumulative effects on woody plants are not easily mitigated. This review summarizes recent research for both forms of salinity damage: specific ion toxicity and osmotic effects.

Diagnostic Enzymology of a-L-Iduronidase with Special Reference to a Sulphated Disaccharide Derived from Heparin

1982 ◽  
Vol 62 (2) ◽  
pp. 193-201 ◽  
Author(s):  
J. J. Hopwood ◽  
Vivienne Muller
Keyword(s):  
Enzyme Activity ◽  
Competitive Inhibitor ◽  
Ph Profile ◽  
Ph Values ◽  
Substrate Structure ◽  
Cultured Skin ◽  
Bivalent Cations ◽  
Competitive Inhibitors ◽  
Specific Ion Effect ◽  
Hydrolysis Of

1. Iduronosyl anhydro[1-3H]mannitol 6-sulphate (IMs), iduronosyl anhydro[1-3H]mannitol, phenyl iduronide (PhI) and 4-methylumbelliferyl iduronide have been compared as substrates for the diagnostic estimation of α-l-iduronidase activity present in human leucocyte and cultured skin fibroblast homogenates. The pH profile of leucocyte and fibroblast iduronidase activity was dependent on substrate structure and concentration, the ionic strength and the nature of the buffer ion used in the assay mixture. 2. NaCl, KBr and Na2SO4 were shown to be parabolic competitive inhibitors of IMs activity, the K1 with fibroblast homogenates being 34, 13.4 and 0.22 mmol/l respectively. NaCl and KBr were shown to have a primary salt effect on the interaction between enzyme and substrate but Na2SO4 appeared to have a specific ion effect at a cationic binding site. 3. NaCl inhibited the hydrolysis of IMs at all pH values studied, whereas NaCl concentrations of 0.2 mol/l inhibited the hydrolysis of PhI at pH values below 3.8 but activated the enzyme at higher incubation pH values. 4. Cu2+ was shown to be a potent non-competitive inhibitor of IMs enzyme activity with an apparent Kl, of approximately 0.02 mmol/l. The enzyme activity was inhibited by Fe2+ (Kl 4 mmol/l), Hg2+ and Ag+, but has not significantly been affected by other univalent or bivalent cations. 5. The presence of solvent and salt effects on apparent Km but not the Vmax. suggest that the binding of IMs to the enzyme involved charge neutralization, and it is inferred that two cationic binding sites are present at the active site. It is postulated that one site specifically binds to the iduronic acid carboxyl group, the other to the 6-sulphate of the anhydromannitol moiety.

A NIPAM-Zwitterion Copolymer: Rheological Interpretation of the Specific Ion Effect on the LCST

2014 ◽  
Vol 215 (11) ◽  
pp. 1077-1091 ◽  
Author(s):  
Francis O. Obiweluozor ◽  
Amin GhavamiNejad ◽  
Saud Hashmi ◽  
Mohammad Vatankhah-Varnoosfaderani ◽  
Florian J. Stadler
Keyword(s):  
Specific Ion Effect

Specific ion effect of H+ on variably charged soil colloid aggregation

Pedosphere ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 844-852
Author(s):  
Yekun ZHANG ◽  
Rui TIAN ◽  
Jia TANG ◽  
Hang LI
Keyword(s):  
Soil Colloid ◽  
Specific Ion Effect
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