scholarly journals On Dielectric Constant and Enzymatic Kinetics

1962 ◽  
Vol 45 (4) ◽  
pp. 21-30 ◽  
Author(s):  
M. Castañeda-Agulló ◽  
Luz M. del Castillo
Keyword(s):  
Dielectric Constant ◽  
Ionic Strength ◽  
Linear Relationship ◽  
Salt Effect ◽  
The Other ◽  
Ion Structure ◽  
Glycine Solution ◽  
Enzymatic Kinetics ◽  
The One ◽  
Low Ionic Strength

A study was made on the effect of glycine on systems involving trypsin and BAEE1 or TSAME on the one hand, or α-chymotrypsin with any of the substrates BAEE, TEE, or PEE, on the other. In all cases there was a linear relationship between the rate logarithm and the reciprocal of the dielectric constant of the glycine solution. The slopes were positive in the reactions of trypsin. In those catalyzed by α-chymotrypsin, the slopes were positive at pH 6.5 or lower, and negative at pH 7.5. However, the effects of glycine differ quantitatively from those of urea or other solvents. The presence of salt modifies somewhat the glycine effects. A low ionic strength increases the effect of glycine on trypsin, but if the inhibition caused by the ionic strength is relatively strong, the addition of glycine partially neutralizes the salt effect. Addition of salt to systems containing α-chymotrypsin always resulted in a diminished effect of glycine. An attempt is made to interpret the anomalies of glycine effects on the basis of its dipolar ion structure.

The aggregation of copper phthalocyanine dyes

1972 ◽  
Vol 25 (8) ◽  
pp. 1661 ◽  
Author(s):  
LC Gruen
Keyword(s):  
Dielectric Constant ◽  
Ionic Strength ◽  
Absorption Spectra ◽  
Copper Phthalocyanine ◽  
Reactive Dyes ◽  
The Other ◽  
Visible Absorption ◽  
Monomeric Species ◽  
Other Hand ◽  
Phthalocyanine Dyes

The visible absorption spectra of two reactive dyes based on the copper phthalocyanine chromophore have been investigated as a function of concentration, temperature, pH, ionic strength, and solvent. The persistence of isosbestic points indicates that an equilibrium exists, over the concentration range investigated, between two forms of the dye only, namely dimer and monomer. The addition of urea exerts a relatively small disaggregating influence on this equilibrium. On the other hand decrease in dielectric constant substantially changes the equilibrium in favour of the monomeric species.

Rationalization of the crystal structure of eudidymite Na2Be2[Si[4] 6O15]·H2O in light of the extended Zintl–Klemm concept

2020 ◽  
Vol 76 (1) ◽  
pp. 41-46
Author(s):  
Angel Vegas ◽  
H. Donald Brooke Jenkins
Keyword(s):  
Crystal Structure ◽  
Ionic Strength ◽  
Crystal Structures ◽  
Complex Network ◽  
The Other ◽  
Structure Generation ◽  
New Approach ◽  
New Development ◽  
Valence Electrons ◽  
The One

The structure of eudidymite is described in light of the extended Zintl–Klemm concept which considers that Na and Be atoms transfer their six valence electrons to the six Si atoms, converting them into Ψ-P which forms a skeleton characteristic of pentels (Group 15 elements) and is similar to that described in the compound (NH4)2Ge[6][Ge[4] 6O15] when analysed in the same manner. The Si[4] skeleton is formed of bilayers that are connected through Be2O6 groups which are in fact fragments of the β-BeO structure which bridge the two contiguous Si-bilayers by sharing O atoms. In this context, the Be atoms play a dual role, i.e. on the one hand converting the Si atoms into Ψ-P, on the other hand replicating fragments of its own β-BeO structure. The Be atoms partially reproduce their own structure despite it being enclosed in a more complex network such as in Na2Be2[Si[4] 6O15]·H2O. Calculations of the ionic strength I considering Si as Ψ-P is energetically more favourable than when I is calculated on the basis of tetravalent Si in the silicate, justifying this new approach of developing the theory of pseudo-structure generation. This approach offers a major new development in the study of crystal structures.

scholarly journals Interaction Between Rabbit Erythroblast Ferritin and Normal Plasma Proteins

Blood ◽  
1974 ◽  
Vol 43 (6) ◽  
pp. 875-883 ◽  
Author(s):  
Hideo Yamada ◽  
Thomas G. Gabuzda ◽  
Marion Berenfeld
Keyword(s):  
Ionic Strength ◽  
Guinea Pig ◽  
Plasma Proteins ◽  
Starch Granule ◽  
Binding Activity ◽  
The Other ◽  
Heat Stable ◽  
Normal Plasma ◽  
Low Ionic Strength ◽  
Plasma Factors

Abstract Erythroblast ferritin (EF), isolated from phenylhydrazine-anemic rabbit marrow, interacts with components of normal plasma and forms a complex separable by starch granule electrophoresis and by dialysis techniques. The binding is facilitated at low ionic strength. The plasma factors responsible for binding EF are present in autologous, as well as homologous, plasma of normal nonimmune rabbits, although binding activities are quite variable in different plasmas. The binding activity for rabbit EF is also present in heterologous plasma of mouse, guinea pig, and man. The active principles in plasma were identified as two heat-stable components which fractionate as immunoglobulins, one as IgG and the other as IgM. The results support the hypothesis that natural antiferritin antibodies of low titer are present in normal plasma.

Environmental and Natural Resources

2018 ◽  
pp. 497-519
Author(s):  
Ralph Hamann ◽  
Jana Hönke ◽  
Tim O’Riordan
Keyword(s):  
Decision Making ◽  
Social Networks ◽  
Civil Society ◽  
Natural Resources ◽  
Linear Relationship ◽  
Environmental Performance ◽  
Environmental Governance ◽  
The Other ◽  
Voluntary Action ◽  
The One

The environment and natural resources constitute a particularly urgent and complex governance domain. A linear relationship is commonly assumed between statehood and environmental performance, but this is not supported by the data, nor the expansive literatures that focus on communities and social networks, on the one hand, and on markets and voluntary action by market-based actors, on the other. ‘Hybrid’ or ‘mixed’ forms of governance involving collaboration between state, business, and civil society actors have emerged, but the effectiveness and legitimacy of such collaboration is likely constrained in areas with very limited statehood. As statehood increases, prospects for such mixed governance improve, though this depends inter alia on characteristics of the state, such as its commitment to participatory and deliberative decision-making. Overall, statehood clearly plays an important role in environmental governance and its outcomes, but in a more multidimensional and often indirect way than commonly assumed.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Conformational Transitions in Escherichia coli Ribosomal RNAs as Visualized by Dedicated STEM

1988 ◽  
Vol 46 ◽  
pp. 176-177
Author(s):  
J.S. Wall ◽  
V. Maridiyan ◽  
S. Tumminia ◽  
J. Hairifeld ◽  
M. Boublik
Keyword(s):  
Ionic Strength ◽  
Three Dimensional ◽  
Conformational Transitions ◽  
Dark Field ◽  
Dimensional Structure ◽  
Ribosomal Rnas ◽  
Field Mode ◽  
Freeze Dried ◽  
High Resolution Images ◽  
Low Ionic Strength

The high contrast in the dark-field mode of dedicated STEM, specimen deposition by the wet film technique and low radiation dose (1 e/Å2) at -160°C make it possible to obtain high resolution images of unstained freeze-dried macromolecules with minimal structural distortion. Since the image intensity is directly related to the local projected mass of the specimen it became feasible to determine the molecular mass and mass distribution within individual macromolecules and from these data to calculate the linear density (M/L) and the radii of gyration.2 This parameter (RQ), reflecting the three-dimensional structure of the macromolecular particles in solution, has been applied to monitor the conformational transitions in E. coli 16S and 23S ribosomal RNAs in solutions of various ionic strength.In spite of the differences in mass (550 kD and 1050 kD, respectively), both 16S and 23S RNA appear equally sensitive to changes in buffer conditions. In deionized water or conditions of extremely low ionic strength both appear as filamentous structures (Fig. la and 2a, respectively) possessing a major backbone with protruding branches which are more frequent and more complex in 23S RNA (Fig. 2a).

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

An Evaluation of a Plasma Fractionation System

1960 ◽  
Vol 4 (01) ◽  
pp. 031-044
Author(s):  
George Y. Shinowara ◽  
E. Mary Ruth
Keyword(s):  
Biological Activity ◽  
Ionic Strength ◽  
Plasma Proteins ◽  
High Concentration ◽  
Significant Evidence ◽  
Native Proteins ◽  
Mobility Data ◽  
Fractionation Procedure ◽  
The Individual ◽  
Low Ionic Strength

SummaryFour primary fractions comprising at least 97 per cent of the plasma proteins have been critically appraised for evidence of denaturation arising from a low temperature—low ionic strength fractionation system. The results in addition to those referable to the recovery of mass and biological activity include the following: The high solubilities of these fractions at pH 7.3 and low ionic strengths; the compatibility of the electrophoretic and ultracentrifugal data of the individual fractions with those of the original plasma; and the recovery of hemoglobin, not hematin, in fraction III obtained from specimens contaminated with this pigment. However, the most significant evidence for minimum alterations of native proteins was that the S20, w and the electrophoretic mobility data on the physically recombined fractions were identical to those found on whole plasma.The fractionation procedure examined here quantitatively isolates fibrinogen, prothrombin and antithrombin in primary fractions. Results have been obtained demonstrating its significance in other biological systems. These include the following: The finding of 5 S20, w classes in the 4 primary fractions; the occurrence of more than 90 per cent of the plasma gamma globulins in fraction III; the 98 per cent pure albumin in fraction IV; and, finally, the high concentration of beta lipoproteins in fraction II.

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