Viscometric Studies on the Stability of DNA-Proflavine Complex-II

1974 ◽  
Vol 29 (3-4) ◽  
pp. 133-135 ◽  
Author(s):  
G. C. Das ◽  
N. N. Das
Keyword(s):  
Ionic Strength ◽  
Melting Temperature ◽  
Thermal Denaturation ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Complex Ii ◽  
Maximum Value ◽  
Dye Binding ◽  
Stabilization Effect ◽  
The Stability

Abstract The binding of proflavine to native DNA increased its stability against thermal denaturation as measured by viscometric method. Up to a moderate ionic strength of 0.058 ᴍ, the melting temperature of the complex increased almost linearly with the increase of dye concentrations and a saturation was reached when one proflavine molecule was added per four to five DNA-Phosphates (D/P≅0.2). The extent of stabilization (ΔTm) produced by dye binding decreased gradually with the increase of ionic strength and no stabilization effect was observed at an ionic strength of about 0.3 ᴍ. The maximum melting temperature attained by Proflavine binding was almost independent of the ionic strength of the medium. The same maximum value was reached as obtained simply by increasing the sodium ion concentration.

Residual phase lignin in haft cooking related to the conditions in the cook

1997 ◽  
Vol 12 (4) ◽  
pp. 225-229
Author(s):  
Cart-in A-S. Gustavsson ◽  
Chritofer T. Lindgren ◽  
Mikael E. Lindström
Keyword(s):  
Hydrogen Sulfide ◽  
Ionic Strength ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Constant Composition ◽  
Hydroxide Ion ◽  
Sulfide Ion ◽  
Residual Phase ◽  
Kraft Cooking ◽  
Very High

Abstract The amount of lignin reacting according to the slow residual phase, i.e. the residual phase lignin, is in many perspectives an interesting issue. The purpose of the present investigation was to develop a mathematical model to show how the amount of residual phase lignin in the kraft cooking of spruce chips (Picm ahies) depends on the conditions in the earlier phases of the cook. The variables studied were hydroxide ion concentration, hydrogen sulfide ion concentration and ionic strength. The liquor-to-wood ratio during pulping was very high to maintain approximately constant chemical concentrations throughout each experiment (so called "constant composition" cooks). An increase in hydroxide ion concentration andtor hydrogen sulfide ion concentration leads to a decrease in the amount of residual phase lignin, while an increase in ionic strength, i.e. sodium ion concentration, leads to an increase. A signiticant result is that the hydrogen sulfide ion concentration has a pronounced influence on the amount of residual phase lignin during a cook at a low hydroxide ion concentration. The amount of residual phase lignin expressed as % lignin on wood, L,, can be described by the following equation developed for "constant composition" cooks (when cooking with a constant sodium ion concentration of 2 mol/L): LT=0,55-0.32*[HO-](-1,3)*ln[HS-] This equation is valid for a concentration of HO- in the range from 0.17 to 1.4, and a hydrogen sulfide ion concentration from 0.07 to 0.6 mol/L.

Studies on the Melting of DNA

1974 ◽  
Vol 29 (3-4) ◽  
pp. 130-132
Author(s):  
Gokul Chandra Das
Keyword(s):  
Ionic Strength ◽  
Melting Temperature ◽  
Thermal Denaturation ◽  
Spectrophotometric Methods ◽  
Melting Temperatures

Abstract The thermal denaturation of the native DNA in solvents of varying salt concentrations was studied by viscometric and spectrophotometric methods. It was observed that within the molarity range of 0.02 ᴍ to 0.3 ᴍ, the melting temperatures obtained by the two independent methods agreed well, but that at lower ionic strength the agreement was not satisfactory. Both the visco­metric and the spectrophotometric measurements showed an increase of the melting temperature with increasing counterion concentration and a levelling off effect in the neighbourhood of 0.3 ᴍ.

Solvent Extraction of Mono(salicylato)beryllium, and the pH Titration of the System Beryllium-Salicylic Acid

1962 ◽  
Vol 15 (2) ◽  
pp. 218 ◽  
Author(s):  
Bruin HJ de ◽  
D Kairaitis ◽  
L Szego
Keyword(s):  
Salicylic Acid ◽  
Ionic Strength ◽  
Solvent Extraction ◽  
Aqueous Solutions ◽  
Distribution Ratio ◽  
Free Ligand ◽  
Ph Titration ◽  
Maximum Value ◽  
The Stability ◽  
Beryllium Complexes

It has been shown that a salicylatoberyllium complex can be extracted from aqueous solutions by aliphatic alcohols. The distribution ratio is a symmetrical function of the logarithm of the free ligand concentration and passes through a maximum value ; the stability constants of the mono- and bis(salicylato)beryllium complexes have been determined from the data for points of equal extraction. The values obtained in this way are β1 = 4.1 x 1012 and β2 = 4.3 x 1022, in an ionic strength of 0.15. They agree fairly well with those obtained by pH-titration procedures, which are β1 = 6.1 x 1012 and β2 =7 x 1022.

scholarly journals ALKALOSIS VERSUS ABNORMAL SODIUM ION CONCENTRATION AS A CAUSE OF TETANY

1923 ◽  
Vol 57 (1) ◽  
pp. 47-63
Author(s):  
W. Denis ◽  
L. von Meysenbug ◽  
Julia Goddard
Keyword(s):  
Sodium Ion ◽  
Ion Concentration

scholarly journals EFFECT OF NONCLASSICAL POLARIZATION OF Na+ AND K+ ON THE STABILITY OF SOIL COLLOIDAL PARTICLES IN SUSPENSION

2017 ◽  
Vol 24 (07) ◽  
pp. 1850019
Author(s):  
DING WU-QUAN ◽  
HE JIA-HONG ◽  
WANG LEI ◽  
LIU XIN-MIN ◽  
LI HANG
Keyword(s):  
Negative Pressure ◽  
Colloidal Particles ◽  
Ion Concentration ◽  
Electrostatic Repulsion ◽  
Adjacent Soil ◽  
Net Pressure ◽  
The Stability ◽  
Two Stages ◽  
Soil Colloids ◽  
Total Average

The study of soil colloids is essential because the stability of soil colloidal particles are important processes of interest to researchers in environmental fields. The strong nonclassical polarization of the adsorbed cations (Na[Formula: see text] and K[Formula: see text] decreased the electric field and the electrostatic repulsion between adjacent colloidal particles. The decrease of the absolute values of surface potential was greater for K[Formula: see text] than for Na[Formula: see text]. The lower the concentration of Na[Formula: see text] and K[Formula: see text] in soil colloids, the greater the electrostatic repulsion between adjacent colloidal particles. The net pressure and the electrostatic repulsion was greater for Na[Formula: see text] than for K[Formula: see text] at the same ion concentration. For K[Formula: see text] and Na[Formula: see text] concentrations higher than 50[Formula: see text]mmol L[Formula: see text] or 100 mmol L[Formula: see text], there was a net negative (or attractive) pressure between two adjacent soil particles. The increasing total average aggregation (TAA) rate of soil colloids with increasing Na[Formula: see text] and K[Formula: see text] concentrations exhibited two stages: the growth rates of TAA increased rapidly at first and then increased slowly and eventually almost negligibly. The critical coagulation concentrations of soil colloids in Na[Formula: see text] and K[Formula: see text] were 91.6[Formula: see text]mmol L[Formula: see text] and 47.8[Formula: see text]mmol L[Formula: see text], respectively, and these were similar to the concentrations at the net negative pressure.

Thermodynamic Studies of the Core Histones:  pH and Ionic Strength Effects on the Stability of the (H3−H4)/(H3−H4)2System†

Biochemistry ◽  
1996 ◽  
Vol 35 (6) ◽  
pp. 2037-2046 ◽  
Author(s):  
Vassiliki Karantza ◽  
Ernesto Freire ◽  
Evangelos N. Moudrianakis
Keyword(s):  
Ionic Strength ◽  
Thermodynamic Studies ◽  
The Core ◽  
Core Histones ◽  
The Stability

The Optimum Quality Index for the Stability of In-Parallel Planar Platform Devices

1999 ◽  
Vol 121 (1) ◽  
pp. 15-20 ◽  
Author(s):  
J. Lee ◽  
J. Duffy ◽  
M. Keler
Keyword(s):  
Optimal Design ◽  
Equilateral Triangle ◽  
Quality Index ◽  
Optimal Shape ◽  
Geometrical Meaning ◽  
Moving Platforms ◽  
Maximum Value ◽  
Dimensionless Ratio ◽  
Parallel Platform ◽  
The Stability

The paper investigates primarily the geometrical meaning of the determinant of the Jacobian (det j) of the three connector lines of a planar in-parallel platform device using reciprocity. A remarkably simple result is deduced: The maximum value of det j namely, det jm is simply one-half of the sum of the lengths of the sides of the moving triangular platform. Further, this result is shown to be independent of the location of the fixed pivots in the base. A dimensionless ratio λ = |det j|/det jm is defined as the quality index (0 ≤ λ ≤ 1) and it is proposed here to use it to measure “closeness” to a singularity. An example which determines the optimal design by comparing different shaped moving platforms having the same det jm is given and demonstrates that the optimal shape is in fact an equilateral triangle

scholarly journals Stability Studies of Transition Metal Chelates of 5-Bromosalicylidene-4-methoxyaniline andSalicylidene-2,3-dimethylaniline as Ligands

2011 ◽  
Vol 8 (4) ◽  
pp. 1911-1915
Author(s):  
N. G. Nadkarni ◽  
K. V. Mangaonkar
Keyword(s):  
Ionic Strength ◽  
Transition Metal ◽  
Stability Constants ◽  
Metal Chelates ◽  
Ternary Complexes ◽  
Water Medium ◽  
Stability Studies ◽  
Binary And Ternary Complexes ◽  
Transition Metal Chelates ◽  
The Stability

Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II), Ni(II), Cu(II) and Zn(II); X = 5-bromosalicylidene-4-methoxyaniline and Y = salicylidene-2,3-dimethylaniline] have been examined pH-metrically at 27±0.5°C and at constant ionic strength, μ = 0.1 M (KCl) in 75 : 25(v/v) 1,4-dioxne-water medium. The stability constants for binary (M-Y) and ternary (M-X-Y) systems were calculated.

scholarly journals Natural microbial polysaccharides as effective factors for modification of the catalytic properties of fungal cellobiose dehydrogenase

2021 ◽  
Author(s):  
Justyna Sulej ◽  
Magdalena Jaszek ◽  
Monika Osińska-Jaroszuk ◽  
Anna Matuszewska ◽  
Renata Bancerz ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Cellobiose Dehydrogenase ◽  
Pycnoporus Sanguineus ◽  
Practical Applications ◽  
Control Value ◽  
Electrochemical Parameters ◽  
Optimum Ph ◽  
Stabilization Effect ◽  
Fungal Polysaccharides ◽  
The Stability

AbstractPolysaccharides are biopolymers composed of simple sugars like glucose, galactose, mannose, fructose, etc. The major natural sources for the production of polysaccharides include plants and microorganisms. In the present work, four bacterial and two fungal polysaccharides (PS or EPS) were used for the modification and preservation of Pycnoporus sanguineus cellobiose dehydrogenase (CDH) activity. It was found that the presence of polysaccharide preparations clearly enhanced the stability of cellobiose dehydrogenase compared to the control value (4 °C). The highest stabilization effect was observed for CDH modified with Rh110EPS. Changes in the optimum pH in the samples of CDH incubated with the chosen polysaccharide modifiers were evidenced as well. The most significant effect was observed for Rh24EPS and Cu139PS (pH 3.5). Cyclic voltammetry used for the analysis of electrochemical parameters of modified CDH showed the highest peak values after 30 days of incubation with polysaccharides at 4 °C. In summary, natural polysaccharides seem to be an effective biotechnological tool for the modification of CDH activity to increase the possibilities of its practical applications in many fields of industry.

Sign in / Sign up

Export Citation Format

Share Document