RELATIONSHIP BETWEEN MOLAR PARAMETERS OF VISCOUS FLOW AND ULTRASONIC WAVE PROPAGATION IN AQUEOUS SOLUTIONS OF AMINO ACIDS

Quantitative structure-property relationship (QSPR) correlations have been widely applied in biological active solutes over several decades. Many new descriptors (parameters) have been developed. Of the many parameters reported in literature, it is argued that the volume (constitutional, geometrical, compressibility) properties play an important role in determining the overall state of proteins consisting of the various amino acids residuals. On basis of experimental data on density, viscosity and ultrasound velocity for aqueous solutions of amino acids, the volume effects in characteristics of impulse transfer and ultrasound wave were studied. The analysis on the correlations between molar parameters of viscosity and ultrasound velocity and molar volume for aqueous solutions of glycine, alanine, aminobutanoic acid, valine, leucine and serine has been carried. It was shown, that the temperature and the concentration dependences of viscosity and ultrasound velocity in the aqueous amino acids solutions may be represented using the molar approach of Krestov-Afanas`ev. An evaluation of the degree of correspondence of the correlation dependences to the experimental data was performed with the minimum distribution dispersion (SD), which was also called the sample standard deviation for regression, and the correlation coefficient (rcorr). It was shown that on basis of the correlations obtained, the densities or the molar volumes can be successfully used for the estimation of unknown values of the viscosities and sound speeds for the amino acid solutions.

Download Full-text

Study of the effect of temperature on the electrical conductivity of aqueous solutions of amino acids

Butlerov Communications ◽

10.37952/roi-jbc-01/19-57-1-91 ◽

2019 ◽

Vol 57 (1) ◽

pp. 91-94

Author(s):

Vera A. Petrukhina ◽

◽

Pavel I. Fedorov ◽

Tatiana A. Kirillova ◽

Ludmila Yu. Tcareva ◽

...

Keyword(s):

Experimental Data ◽

Amino Acids ◽

Electrical Conductivity ◽

Amino Acid ◽

Aqueous Solutions ◽

Arrhenius Equation ◽

Effect Of Temperature ◽

Acid Solutions ◽

Hydrogen Ions ◽

Amino Acid Solutions

It is well-known fact that water is a universal solvent due to its physicochemical properties and dielectric constant. Therefore, the majority of substances with a crystalline structure and the structure close to it are well soluble in water due to the dissociation of molecules into ions. Amino acids are organic ampholytes – substances capable of being in ionic forms in water. The quantitative and qualitative composition of ampholytes depends on the structure and composition of amino acids and pH of solution. The interaction of amino acid ions in solution with hydrogen ions and hydroxyl leads to the formation of complex cations and anions. The presence of amino and carboxyl groups in amino acid molecules contributes to the formation of inter-ion positively and negatively charged complexes which leads to the decrease in their mobility and electrical conductivity of solutions. It is observed with increasing concentration of amino acid solutions. The conductivity of amino acid solutions is also influenced by temperature which has a non-linear relationship. We have proposed the approach based on studying the effect of temperature on the equivalent electrical conductivity at infinite dilution λ∞ and describing the experimental data λ∞(Т) by the exponential Arrhenius equation. This article studies the possibility of describing the experimental data λ∞(Т) for aqueous solutions of a number of amino acids by this equation. It is shown that the Arrhenius equation with the found activation energy values adequately describes the dependences of limiting equivalent conductivity on temperature for aqueous solutions of valine, leucine, isoleucine, threonine, lysine, methionine, phenylalanine, L-aspartic and D-aspartic acids, histidine, arginine.

Download Full-text

Chiral Phonons in Biocrystals

10.21203/rs.3.rs-248321/v1 ◽

2021 ◽

Author(s):

Won Jin Choi ◽

Keiichi Yano ◽

Minjeong Cha ◽

Felippe Colombari ◽

Yichun Wang ◽

...

Keyword(s):

Experimental Data ◽

Amino Acids ◽

Theoretical Analysis ◽

Lattice Vibrations ◽

Structure Property ◽

Spectral Signatures ◽

Structure Property Relationships ◽

Left And Right ◽

Collective Vibrations ◽

Chiroptical Spectroscopy

Abstract Chiral phonons are concerted mirror-symmetric movements of atomic groups connected by covalent and intermolecular bonds. Finding chiral phonons in biocrystals is fundamentally and technologically important because these lattice vibrations should be highly specific to their short- and long-range organizations. Based on theoretical and experimental data they might be expected but not identified or utilized. Here we show that terahertz chiroptical spectroscopy enables registration and attribution of chiral phonons in microcrystals of numerous amino acids and dipeptides. Theoretical analysis and computer simulations confirm that sharp mirror-symmetric bands observed for left and right enantiomers originate from collective vibrations of biomolecules interconnected by hydrogen bonds into helical chains. Structure-property relationships for strong phonons with rotatory components in biocrystals were also identified. Bladder stones and health supplements display strong spectral signatures of chiral phonons indicating their immediate importance for biomedicine.

Download Full-text

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

International Astronomical Union Colloquium ◽

10.1017/s025292110001469x ◽

1997 ◽

Vol 161 ◽

pp. 179-187

Author(s):

Clifford N. Matthews ◽

Rose A. Pesce-Rodriguez ◽

Shirley A. Liebman

Keyword(s):

Amino Acids ◽

Solar System ◽

Hydrogen Cyanide ◽

Nitrogen Heterocycles ◽

Laboratory Studies ◽

Heterogeneous Solids ◽

The Many ◽

Comet Halley ◽

The Impact ◽

By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Download Full-text

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152136 ◽

1989 ◽

Vol 47 ◽

pp. 32-33

Author(s):

S.A.C. Gould ◽

B. Drake ◽

C.B. Prater ◽

A.L. Weisenhorn ◽

S.M. Lindsay ◽

...

Keyword(s):

Amino Acids ◽

Dna Sequencing ◽

Aqueous Solutions ◽

Atomic Force Microscope ◽

Piezoelectric Crystal ◽

Atomic Force ◽

Structure Of Molecules ◽

Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

Download Full-text

HEATS OF SOLUTION, HEATS OF DILUTION, AND SPECIFIC HEATS OF AQUEOUS SOLUTIONS OF CERTAIN AMINO ACIDS

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)75321-0 ◽

1935 ◽

Vol 108 (1) ◽

pp. 161-185

Author(s):

Charles A. Zittle ◽

Carl L.A. Schmidt

Keyword(s):

Amino Acids ◽

Aqueous Solutions ◽

Specific Heats ◽

Heats Of Solution ◽

Heats Of Dilution

Download Full-text

Reactivity in social scientific experiments: what is it and how is it different (and worse) than a Placebo effect?

European Journal for Philosophy of Science ◽

10.1007/s13194-021-00350-z ◽

2021 ◽

Vol 11 (2) ◽

Author(s):

María Jiménez-Buedo

Keyword(s):

Experimental Data ◽

Conceptual Framework ◽

Placebo Effect ◽

Placebo Effects ◽

Causal Inferences ◽

Scientific Experiments ◽

Social Scientific ◽

The Many ◽

Definition Of ◽

In Virtue Of

AbstractReactivity, or the phenomenon by which subjects tend to modify their behavior in virtue of their being studied upon, is often cited as one of the most important difficulties involved in social scientific experiments, and yet, there is to date a persistent conceptual muddle when dealing with the many dimensions of reactivity. This paper offers a conceptual framework for reactivity that draws on an interventionist approach to causality. The framework allows us to offer an unambiguous definition of reactivity and distinguishes it from placebo effects. Further, it allows us to distinguish between benign and malignant forms of the phenomenon, depending on whether reactivity constitutes a danger to the validity of the causal inferences drawn from experimental data.

Download Full-text

Experimental data on the removal of acid orange 10 dye from aqueous solutions using TiO2/Na-Y zeolite and BiVO4/Na-Y zeolite nanostructures: A comparison study

Data in Brief ◽

10.1016/j.dib.2021.106869 ◽

2021 ◽

Vol 35 ◽

pp. 106869

Author(s):

Behzad Rahimi ◽

Nayereh Rezaie-Rahimi ◽

Negar Jafari ◽

Ali Abdolahnejad ◽

Afshin Ebrahimi

Keyword(s):

Experimental Data ◽

Aqueous Solutions ◽

Comparison Study ◽

Y Zeolite ◽

Acid Orange ◽

Acid Orange 10

Download Full-text

THE METHOD OF INCREMENTS — A WAVEFUNCTION-BASED AB-INITIO CORRELATION METHOD FOR SOLIDS

International Journal of Modern Physics B ◽

10.1142/s0217979207043592 ◽

2007 ◽

Vol 21 (13n14) ◽

pp. 2204-2214 ◽

Cited By ~ 7

Author(s):

BEATE PAULUS

Keyword(s):

Experimental Data ◽

Ab Initio ◽

Ground State ◽

Infinite System ◽

Correlation Energy ◽

Correlation Method ◽

Many Body ◽

Hartree Fock ◽

The Many ◽

Good Agreement

The method of increments is a wavefunction-based ab initio correlation method for solids, which explicitly calculates the many-body wavefunction of the system. After a Hartree-Fock treatment of the infinite system the correlation energy of the solid is expanded in terms of localised orbitals or of a group of localised orbitals. The method of increments has been applied to a great variety of materials with a band gap, but in this paper the extension to metals is described. The application to solid mercury is presented, where we achieve very good agreement of the calculated ground-state properties with the experimental data.

Download Full-text