bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential entropy and time
Authors: Garbaczewski Piotr
Published: October 2008

We give a detailed analysis of the Gibbs-type entropy notion and its dynamical behavior in case of time-dependent continuous probability distributions of varied origins: related to classical and quantum systems. The purpose-dependent usage of conditional Kullback-Leibler and Gibbs (Shannon) entropies is explained in case of non-equilibrium Smoluchowski processes. A very different temporal behavior of Gibbs and Kullback entropies is confronted. A specific conceptual niche is addressed, where quantum von Neumann, classical Kullback-Leibler and Gibbs entropies can be consistently introduced as information measures for the same physical system. If the dynamics of probability densities is driven by the Schrödinger picture wave-packet evolution, Gibbs-type and related Fisher information functionals appear to quantify nontrivial power transfer processes in the mean. This observation is found to extend to classical dissipative processes and supports the view that the Shannon entropy dynamics provides an insight into physically relevant non-equilibrium phenomena, which are inaccessible in terms of the Kullback-Leibler entropy and typically ignored in the literature.
Second law analysis of laminar flow in a channel filled with saturated porous media: a numerical solution
Authors: Hooman Kamel , Ejlali Arash
Published: October 2008

This paper investigates entropy generation due to forced convection in a porous medium sandwiched between two parallel plates one of them being subjected to a uniform heat flux and the other one insulated. Our results showed that viscous dissipation will affect the entropy generation rate at the centerline of the channel since viscous dissipation is a quadratic function of velocity [1-3]. Neglecting the Darcy dissipation term in comparison with the terms added by Al-Hadrami et al. [4], will lead to the misunderstanding that fluid friction has no effect on the entropy generation rate at the tube centerline where the velocity derivative vanishes due to symmetry. Though the term added by [4] is O(Da) compared to the Darcy term one should not drop it unless the clear flow solution is sought [5-7]. Moreover, as stated by Nield [1], one should not use just the term involving velocity derivatives, as some authors have done in the past, for example [8-11]. Though in this paper the viscous dissipation effects in the energy equation are neglected, we have take them into account when it came to the entropy generation analysis.
The Symmetry Principle
Authors: Rosen Joe
Published: October 2008

The symmetry principle is described in this paper. The full details are given in the book: J. Rosen, Symmetry in Science: An Introduction to the General Theory (Springer-Verlag, New York, 1995).
Second Law Analysis in Convective Heat and Mass Transfer
Authors: Magherbi M. , Abbassi H. , Hidouri N. , Brahim A.  Ben
Published: October 2008

This paper reports the numerical determination of the entropy generation due to heat transfer, mass transfer and fluid friction in steady state for laminar double diffusive convection, in an inclined enclosure with heat and mass diffusive walls, by solving numerically the mass, momentum, species conservation and energy balance equations, using a Control Volume Finite-Element Method. The influences of the inclination angle, the thermal Grashof number and the buoyancy ratio on total entropy generation were investigated. The irreversibilities localization due to heat transfer, mass transfer and fluid friction is discussed for three inclination angles at a fixed thermal Grashof number.
Utility Function from Maximum Entropy Principle
Authors: Darooneh Amir  H.
Published: October 2008

Recently we used the maximum entropy principle for finding the price density in a multi agent insurance market. The result is similar to what the Buhlmann had obtained by maximizing the utility function. Here we begin with the price density that is derived by applying the maximum entropy principle to a conservative economic system (exchange market), then reverse the Buhlmann calculation to find the utility function and the risk aversion of agents with respect to this density.
Unsteady Volumetric Entropy Generation Rate in Laminar Boundary Layers
Authors: Walsh E. , Hernon D.
Published: October 2008

The prediction of the entropy generation rate in laminar shear layers is treated as steady, even in the presence of high levels of free stream turbulence. Here we highlight the deficiencies of this approach by quantifying the magnitude of entropy generation rate fluctuations in the laminar boundary layer subjected to free stream turbulence. We find fluctuation levels in excess of 100% in the near wall region, thereby indicating the need to account for the unsteadiness in laminar boundary layers subjected to free stream turbulence.
Deformed Density Matrix and Quantum Entropy of the Black Hole
Authors: Shalyt-Margolin A. E.
Published: October 2008

In the present work the approach - density matrix deformation - earlier developed by the author to study a quantum theory of the Early Universe (Planck's scales) is applied to study a quantum theory of black holes. On this basis the author investigates the information paradox problem, entropy of the black hole remainders after evaporation, and consistency with the holographic principle. The possibility for application of the proposed approach to the calculation of quantum entropy of a black hole is considered.
Remarks on the Compatibility of Opposite Arrows of Time II
Authors: Zeh H.  D.
Published: October 2008

In a series of papers [1,2,3], Lawrence Schulman presented examples which demonstrate the compatibility of opposite arrows of time in various situations. In a previous letter to this journal [4] I questioned some of them for not being realistic in spite of being logically correct. Schulman replied [5] to these objections in a letter directly succeeding my one. I am here trying to clarify some aspects of the dispute, thereby further explaining and supporting my previous conclusions.
Entropy Generation in Pressure Gradient Assisted Couette Flow with Different Thermal Boundary Conditions
Authors: Aziz Abdul
Published: October 2008

The present paper is concerned with an analytical study of entropy generation in viscous, incompressible Couette flow between a stationary plate and a moving plate. The flow induced by the moving plate is assisted by a constant pressure gradient along the flow direction. Four different combinations of thermal boundary conditions are investigated: (a) plates at different temperatures, (b) stationary plate at a fixed temperature and moving plate subjected to a constant heat flux, (c) stationary plate at a fixed temperature and convection at the moving plate, and (d) convection at both plates. Besides the velocity and temperature profiles, dimensionless results are presented for the entropy generated due to heat transfer, the entropy generated due to viscous dissipation, and the total entropy generation. These results illustrate the effect of pressure gradient, temperature asymmetry, heat flux, convection Biot numbers, and ambient temperatures. For certain combinations of thermal variables, the total entropy generated is minimized.
Entropy and Energy in Quantum Measurement
Authors: Schlatter Andreas  E.
Published: October 2008

On the basis of the classical axioms of non relativistic quantum mechanics, we develop a model for the interplay between energy and entropy in the process of quantum measurement and shed light on the scope of some of the axioms with regard to the measurement problem.
Inference with the Median of a Prior
Authors: Mohammadpour Adel , Mohammad-Djafari Ali
Published: October 2008

We consider the problem of inference on one of the two parameters of a probability distribution when we have some prior information on a nuisance parameter. When a prior probability distribution on this nuisance parameter is given, the marginal distribution is the classical tool to account for it. If the prior distribution is not given, but we have partial knowledge such as a fixed number of moments, we can use the maximum entropy principle to assign a prior law and thus go back to the previous case. In this work, we consider the case where we only know the median of the prior and propose a new tool for this case. This new inference tool looks like a marginal distribution. It is obtained by first remarking that the marginal distribution can be considered as the mean value of the original distribution with respect to the prior probability law of the nuisance parameter, and then, by using the median in place of the mean.
Symmetry Studies and Decompositions of Entropy
Authors: Viana Marlos
Published: October 2008

This paper describes a group-theoretic method for decomposing the entropy of a finite ensemble when symmetry considerations are of interest. The cases in which the elements in the ensemble are indexed by {1,2,...,n} and by the permutations of a finite set are considered in detail and interpreted as particular cases of ensembles with elements indexed by a set subject to the actions of a finite group. Decompositions for the entropy in binary ensembles and in ensembles indexed by short DNA words are discussed. Graphical descriptions of the decompositions of the entropy in geological samples are illustrated. The decompositions derived in the present cases follow from a systematic data analytic tool to study entropy data in the presence of symmetry considerations.
Editor-in-Chief's Report
Authors: Petitjean Michel
Published: October 2008

Entropy has been launched in 1999 by Dr. Shu-Kun Lin, and it is now in its eight year.[...]
Structuring Information and Entropy: Catalyst as Information Carrier
Authors: Trambouze Pierre  J.
Published: October 2008

Many authors tried to exploit the similarities between expressions of the statistical thermodynamics for the entropy and those of Shannon's information theory. In a new approach, we highlight the role of information involved in chemical systems, in particular in the interaction between catalysts and reactants, what we call structuring information. By means of examples, we present some applications of this concept to the biosphere, by visiting a very vast domain going from the appearance of life on earth to its present evolution.
Open Access Publishing Policy and Efficient Editorial Procedure
Authors: Lin Shu-Kun , McPhee Derek  J. , Muguet Francis  F.
Published: October 2008

n/a
Calculations of System Aging through the Stochastic Entropy
Authors: Rocchi Paolo
Published: October 2008

The present research discusses four ‘physical’ models of system and calculates thereliability function during system’s aging and maturity on the basis of the system structure.
On the Propagation of Blast Wave in Earth′s Atmosphere: Adiabatic and Isothermal Flow
Authors: Yadav R. , Agarwal P. , Sharma Atul
Published: October 2008

Adiabatic and isothermal propagations of spherical blast wave produced due to a nuclear explosion have been studied using the Energy hypothesis of Thomas, in the nonuniform atmosphere of the earth. The explosion is considered at different heights. Entropy production is also calculated along with the strength and velocity of the shock. In both the cases; for adiabatic and isothermal flows, it has been found that shock strength and shock velocity are larger at larger heights of explosion, in comparison to smaller heights of explosion. Isothermal propagation leads to a smaller value of shock strength and shock velocity in comparison to the adiabatic propagation. For the adiabatic case, the production of entropy is higher at higher heights of explosion, which goes on decreasing as the shock moves away from the point of explosion. However for the isothermal shock, the calculation of entropy production shows negative values. With negative values for the isothermal case, the production of entropy is smaller at higher heights of explosion, which goes on increasing as the shock moves away from the point of explosion. Directional study of the shock motion and entropy production show that in both the cases of adiabatic and isothermal flow, shock strength and shock velocity are larger in upward motion of the shock, in comparison to the downward motion of the shock. For adiabatic flow, entropy production is larger in upward motion of the shock; whereas, with negative values, entropy production is smaller in upward motion of the isothermal shock. For the adiabatic case, the profiles of shock strength, shock velocity and entropy production are smooth and have the largest value in vertically upward direction and have the lowest value in vertically downward direction, forming the oval shape. For the isothermal case, the profiles of shock strength and shock velocity show similar trend as that for adiabatic case but the profile of entropy production shows opposite trend. The profiles maintain their shape as the shock moves away. Comparison with observed values of shock velocity shows that isothermal case produces better results in comparison to the adiabatic case.
Entropy and Effective Support Size
Authors: Grendar Marian
Published: October 2008

Notion of Effective size of support (Ess) of a random variable is introduced. A smallset of natural requirements that a measure of Ess should satisfy is presented. The measure withprescribed properties is in a direct (exp-) relationship to the family of R ́nyi’s α-entropies which eincludes also Shannon’s entropy H. Considerations of choice of the value of α imply that exp(H)appears to be the most appropriate measure of Ess.Entropy and Ess can be viewed thanks to their log / exp relationship as two aspects of the samething. In Probability and Statistics the Ess aspect could appear more basic than the entropic one.
Generalized Ideal Gas Equations for Structureful Universe
Authors: Afridi Shahid , Khan Khalid
Published: October 2008

We have derived generalized ideal gas equations for a structureful universe consistingof all forms of matters. We have assumed a universe that contains superclusters. Superclusters arethen made of clusters. Each cluster can be further divided into smaller ones and so on. We havederived an expression for the entropy of such a universe. Our model is rather independent of thegeometry of the intermediate clusters. Our calculations are valid for a non-interacting universewithin non-relativistic limits. We suggest that structure formation can reduce the expansion rateof the universe.
Time in Quantum Measurement
Authors: Schlatter Andreas
Published: October 2008

Based on a model of quantum measurement we derive an estimate for the external measurement-time. Some interesting consequences will be analyzed.
Thermodynamic Analysis of Gravity-driven Liquid Film along an Inclined Heated Plate with Hydromagnetic and Viscous Dissipation Effects
Authors: Aïboud-Saouli Soraya , Saouli Salah , Settou Noureddine , Meza Nouredine
Published: October 2008

The purpose of this work is to investigate the entropy generation in a laminar,gravity-driven conducting liquid film with fully developed velocity flowing along an inclineheated plate in the presence of a transverse magnetic field. The upper surface of the liquidfilm is considered free and adiabatic. The effect of heat generation by viscous dissipation isincluded in the analysis. The influence of the applied magnetic field and the viscousdissipation on velocity, temperature and entropy generation is examined.
A Utility-Based Approach to Some Information Measures
Authors: Friedman Craig , Huang Jinggang , Sandow Sven
Published: October 2008

We review a decision theoretic, i.e., utility-based, motivation for entropy and Kullback-Leibler relative entropy, the natural generalizations that follow, and various properties of thesegeneralized quantities. We then consider these generalized quantities in an easily interpreted spe-cial case. We show that the resulting quantities, share many of the properties of entropy andrelative entropy, such as the data processing inequality and the second law of thermodynamics.We formulate an important statistical learning problem – probability estimation – in terms of ageneralized relative entropy. The solution of this problem reflects general risk preferences via theutility function; moreover, the solution is optimal in a sense of robust absolute performance.
An Adaption of the Jaynes Decision Algorithm
Authors: Tarko Vlad
Published: October 2008

There are two types of decisions: given the estimated state of affairs, one decidesto change oneself in a certain way (that is best suited for the given conditions); given whatone is, one decides to change the state of affairs in a certain way (that is best suited for whatone wants for oneself). Jaynes' approach to decision theory accounts only for the first type ofdecisions, the case when one is just an observer of the external world and the decisiondoesn't change the world. However, many decisions involve the wish to transform theexternal environment. To account for this we need to add an additional step in Jaynes'proposed algorithm.
Second Law Analysis of a non-Newtonian Laminar Falling Liquid Film Along an Inclined Heated Plate
Authors: Gorla Rama Subba Reddy , Pratt David M.
Published: October 2008

The second law analysis of heat transfer of a non-Newtonian, laminar fallingliquid film along an inclined heated plate is investigated. The upper surface of the liquidfilm is considered free and adiabatic. Velocity and temperature profiles are obtainedanalytically and used to compute the entropy generation number (Ns), irreversibility ratio (Φ) and the Bejan number (Be) for several values of the viscous dissipation parameter(Br -1), viscosity index (n) and the dimensionless axial distance (X). The Bejan numberincreases in the transverse direction and decreases as the viscous dissipation parameter(BrΩ -1) increases. The numerical results show that the Bejan number decreases as theviscous dissipation parameter (BrΩ -1), Peclet number (Pe) and the viscosity index (n)increase.
Probability as a Physical Motive
Authors: Martin Peter
Published: October 2008

Recent theoretical progress in nonequilibrium thermodynamics, linking thephysical principle of Maximum Entropy Production (“MEP”) to the information-theoretical“MaxEnt” principle of scientific inference, together with conjectures from theoreticalphysics that there may be no fundamental causal laws but only probabilities for physicalprocesses, and from evolutionary theory that biological systems expand “the adjacentpossible” as rapidly as possible, all lend credence to the proposition that probability shouldbe recognized as a fundamental physical motive. It is further proposed that spatial order andtemporal order are two aspects of the same thing, and that this is the essence of the secondlaw of thermodynamics.
Distillation of a Complex Mixture. Part I: High Pressure Distillation Column Analysis: Modeling and Simulation
Authors: Mustapha Douani , Fatima Ouadjenia , Sabria Terkhi
Published: October 2008

In this analysis, based on the bubble point method, a physical model wasestablished clarifying the interactions (mass and heat) between the species present in thestreams in circulation in the column. In order to identify the externally controlled operatingparameters, the degree of freedom of the column was determined by using Gibbs phase rule.The mathematical model converted to Fortran code and based on the principles of: 1) Globaland local mass conservation balance, 2) Enthalpy balance, and 3) Vapour-liquid equilibriumat each tray, was used to simulate the behavior of the column, concentration distributions,temperature and streams for each phase along the column at high pressure in each tray. Theenergy consumption at the condenser and the boiler was also evaluated using the Starlingequation of state.
Entropy Characteristic on Harmonious Unifying Hybrid Preferential Networks
Authors: Li Yong , Fang Jin-Qing , Bi Qiao , Liu Qiang
Published: October 2008

Based on the harmonious unifying hybrid preferential model (HUHPM) networkproposed by our group, the entropy characteristic of an un-weighted HUHPM-BA networkand a weighted HUHPM-BBV network are investigated as the total hybrid ratio d/r ischanged. We derive and compute the general relation of the power exponent of the degreedistribution with the entropy by using the Boltzmann-Gibbs entropy (BGS) and the Tsallisnon-extensive entropy (Sq). It is found that the BGS decreases as d/r increases and thecurrent of the BGS along with hybrid ratio d/r or exponent γ of power-law is in agreementbetween numerical simulation and theoretical analysis. The relationship between the Sq andcharacteristic parameter q under different d/r is also given. And the Sq approaches to theBGS when q → 1. These results can provide a better understanding for evolutioncharacteristic in growing complex networks and further applications in networkengineering are of prospective potential.
The Natural Philosophy of Work
Authors: Salthe Stanley  N.
Published: October 2008

Work, by dissipative structures (DS), imposes delay on energy gradientdegradation. It diverts energy flow into DS maintenance while enhancing energy degradation.DS can be viewed as tradeoffs between enhancing entropy production maximization (themaximum entropy production principle, MEP) by way of convective gradient degradation,and the need to maintain DS form, which is what mediates the convective dissipation. Thistradeoff frameworked the origin of living DS. In the Big Bang, the Universe departedincreasingly from an ordered state of low entropy. As a result the Second Law (locally, dS>or = 0) became an ever more powerful attractor, insuring that work could have only limitedenergy efficiency (utilization / throughput). That is, the ‘>’ in ‘dS > or = 0’ increased onaverage locally as the universe departed further from thermodynamic equilibrium. Energyefficiency becomes significant in the context of possible energy shortage, which impliesembodied agency, implying in turn the possibility of some stability into the future. Energyefficiency is needed in living DS which yet serve MEP by becoming relatively less energyefficient when striving. Biodiversity multiplies modes of energy consumption, alsofurthering MEP by compensating for the diversion of energy flow into the maintenance ofliving DS. Modular (hierarchical) structure is very stable to perturbations, and also generatesthe variety requisite for adaptive flexibility, affording as well evolutionary access toincreased adjacent possibilities. Dynamical rate separation between hierarchical levelsstreamlines energy flows, enhancing orderly energy gradient degradation. I conjecture thatnew levels are interpolated when that fosters MEP overall. Of the three phases of energyflow -- low level conduction, mid level convection, and high level explosion -- orderlyconvection associates with DS form, constraining moderated energy flows, and defusingpotential explosions.
Thermodynamics of Horizons from a Dual Quantum System
Authors: Sarkar Sudipta , Padmanabhan T.
Published: October 2008

It was shown recently that, in the case of Schwarschild black hole, one can obtainthe correct thermodynamic relations by studying a model quantum system and using a partic-ular duality transformation. We study this approach further for the case a general sphericallysymmetric horizon. We show that the idea works for a general case only if we define the en-tropy S as a congruence (“observer”) dependent quantity and the energy E as the integral overthe source of the gravitational acceleration for the congruence. In fact, in this case, one recov-ers the relation S = E/2T between entropy, energy and temperature previously proposed byone of us in gr-qc/0308070. This approach also enables us to calculate the quantum correc-tions of the Bekenstein-Hawking entropy formula for all spherically symmetric horizons.
A Model of Time
Authors: Schlatter Andreas  E.
Published: October 2008

Based on a mathematical model of quantum measurement we derive some properties of intuitive time.
Entropy of Relativistic Mono-Atomic Gas and Temperature Relativistic Transformation in Thermodynamics
Authors: Bormashenko Edward
Published: October 2008

It is demonstrated that the entropy of the ideal mono-atomic gas comprisingidentical spherical atoms is not conserved under the Planck-Einstein like relativistictemperature transformation, as a result of the change in the number of atomic degrees offreedom. This fact supports the idea that there is no universal relativistic temperaturetransformation.
On Darcy-Brinkman Equation: Viscous Flow Between Two Parallel Plates Packed with Regular Square Arrays of Cylinders
Authors: Liu Haidong , Patil Prabhamani  R. , Narusawa Uichiro
Published: October 2008

Effects of the bounding solid walls are examined numerically for slow flow overregular, square arrays of circular cylinders between two parallel plates. A local magnitudeof the rate of entropy generation is used effectively to determine the flow region affected bythe presence of the solid boundary. Computed axial pressure gradients are compared to thecorresponding solution based on the Darcy-Brinkman equation for porous media in whichthe effective viscosity appears as an additional property to be determined from the flowcharacteristics. Results indicate that, between two limits of the Darcian porous medium andthe viscous flow, the magnitude of μ (the ratio of the effective viscosity to the fluid ˆviscosity) needs to be close to unity in order to satisfy the non-slip boundary conditions atthe bounding walls. Although the study deals with a specific geometric pattern of the porousstructure, it suggests a restriction on the validity of the Darcy-Brinkman equation to modelhigh porosity porous media. The non-slip condition at the bounding solid walls may beaccounted for by introducing a thin porous layer with μ = 1 near the solid walls. ˆ
On the So-Called Gibbs Paradox, and on the Real Paradox
Authors: Ben-Naim Arieh
Published: October 2008

Two versions of the so-called Gibbs paradox are discussed. Both of these areshown to be non-paradoxes. It is also shown that there is a different real paradox that emergesfrom Gibbs writings.
Distillation of a Complex Mixture. Part II: Performance Analysis of a Distillation Column Using Exergy
Authors: Mustapha Douani , Sabria Terkhi , Fatima Ouadjenia
Published: October 2008

To analyze the performance of the separation process, we have introduced thethermodynamic concept of exergy through the exergetic efficiency of the column. Thesimulation results show that the exergetic output is relatively low and that the producedirreversibility fluxes are distributed throughout the whole column in a non-uniform manner.They are particularly significant in the condenser, boiler and tray feed. The influence of thevarious operating parameters (temperature, concentration and irreversibility in both sectionsof the column) is also established. To emphasize the results, the relation in equation 17, ispresented graphically to evaluate the cumulative irreversibilities from the overhead to thebottom. This presentation is equivalent to the Grassmann diagram.
A Simple Thermodynamic Analysis of Photosynthesis
Authors: Albarrán-Zavala E. , Angulo-Brown F.
Published: October 2008

In this paper we present a comparative study of nine photosynthetic pathways bymeans of their thermodynamic performance. The comparison is made by using the thermalefficiency of light-to-chemical energy conversion and the so-called ecological criterionarising from finite-time thermodynamics. The application of both criteria leads tophotosynthesis made by metaphytes and non sulfur purple bacteria as those of bestthermodynamic performance. In spite of the simplicity of our thermodynamic approachsome insights over the low overall efficiency of photosynthesis is suggested.
Geometric Entropy of Self-Gravitating Systems
Authors: Fatibene Lorenzo , Ferraris Marco , Francaviglia Mauro , Mercadante Silvio
Published: October 2008

We shall review different approaches to the entropy of self-gravitating systems inGeneral Relativity. Then we shall discuss in detail the macroscopic approach based on a la `Clausius point of view. Recent developments will be reviewed discussing the aims as well asthe assumptions which the framework is based on.
On Optimization of a Non-Endorreversible Curzon-Ahlborn Cycle
Authors: Ladino-Luna Delfino
Published: October 2008

A non-endoreversible Curzon and Ahlborn cycle is analyzed by introducing afactor of non-endoreversibility. The form of power output and ecological function, andthe role of this factor is discussed. The Gutkowics-Krusin, Procaccia and Ross method tobuild a general expression for both the power output and the ecological function for thiscycle is used. A numerical analysis of these expresions is made and the results arecompared with other kind of approaches found in the literature of finite timethermodynamics.
Design of Experiments: Useful Orthogonal Arrays for Number of Experiments from 4 to 16
Authors: Bolboacă Sorana D. , Jäntschi Lorentz
Published: October 2008

A methodology for the design of an experiment is proposed in order to find asmany schemes as possible with the maximum number of factors with different levels for thesmallest number of experimental runs. An algorithm was developed and homemadesoftware was implemented. The abilities in generation of the largest groups of orthogonalarrays were analyzed for experimental runs of 4, 6, 8, 9, 10, 12, 14, 15, and 16. The resultsshow that the proposed method permits the construction of the largest groups of orthogonalarrays with the maximum number of factors.
Ion Sensors
Authors: Antonijevic Milan
Published: October 2008

Ion sensors offer an attractive solution for continuously evaluating the content of certain ionic species in aqueous media.[...]
17O NMR of Enamino-Diesters: Intramolecular Hydrogen Bonding in 5-Alkylaminomethylene-2,2-dimethyl-1,3-dioxane-4,6-diones
Authors: Zhuo Jin-Cong
Published: October 2008

Natural abundance 17O NMR spectra of a series of 5-alkylaminomethylene-2,2-dimethyl-1,3-dioxane-4,6-diones, recorded in acetonitrile solution, are reported. The δ(17O) values correlate well with those of 4-alkylaminobut-3-en-2-ones and with the pKa values of amines. The effects of the N-alkyl groups on the 17O shift values is diminished, owing to the resonance effects of the alkoxy groups. The shift difference (DδHB) between the two carbonyl groups is mainly attributed to the intramolecular hydrogen bonding and depends on the donor property of the amino group.
New Anticandidous 2-Alkylthio-6-aminobenzothiazoles
Authors: Sidóová Eva , Loos Dusan , Bujdáková Helena , Kallová Jana
Published: October 2008

The synthesis and antimicrobial activity of six new 2-alkenyl-6-aminobenzothiazoles are reported. The new compounds were prepared by alkenylation of the potassium salt of 6-amino-2-mercaptobenzothiazole with alkenyl bromides. The structure of the compounds was verified by 1H NMR spectra. The compounds have shown antibacterial activity against Staphylococcus aureus and anticandidous activity against Candida albicans. The optimum structure of the studied compounds has been calculated by quantum chemistry AM1 method. The theoretical values of lipophilicity were calculated for all alkenyl substituents.
Synthesis of 1,2,3,4,5,6-Hexahydrophosphinine 1-Oxides by Catalytic Hydrogenation of 3-Phosphabicyclo[3.1.0]hexane 3-Oxides
Authors: Keglevich György , Tungler Antal , Újszászy Kálmán , Novák Tibor , Tôke László
Published: October 2008

Synthesis of 1,2,3,4,5,6-hexahydrophosphinine 1-oxides by catalytic hydrogenation of 3-phosphabicyclo[3.1.0]hexane 3-oxides was reported in this communication.
Synthesis of 1,2,3,6-Tetrahydrophosphinine 1-Oxides by Regioselective Reduction of 1,2-Dihydrophosphinine 1-Oxides
Authors: Keglevich György , Újszászy Kálmán , Ludányi Krisztina , Szöllôsy Áron , Tôke László
Published: October 2008

Synthesis of 1,2,3,6-tetrahydrophosphinine 1-oxides by regioselective reduction of 1,2-dihydrophosphinine 1-oxides was reported in this communication.
Synthesis and 1,3-Dipolar Cycloaddition Reactions of Chiral Maleimides
Authors: Ondrus Vladimir , Fisera Lubor
Published: October 2008

New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino acids 3a-f in the presence of Et3N with release of furan to give the requisite novel chiral imides 4a-f in good to moderate yields. The stereoselectivity of 1,3-dipolar cycloaddition of nitrile oxides with prepared chiral imides 4a-f is investigated.
Environmental Research and Public Health
Authors: Tchounwou Paul B.
Published: October 2008

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Coumestrol, Bisphenol-A, DDT, and TCDD Modulation of Interleukin-2 Expression in Activated CD+4 Jurkat T Cells
Authors: Ndebele Kenneth , Tchounwou Paul  B. , McMurray Robert  W.
Published: October 2008

Endogenous estrogens are known to modulate several components of immune response, including interleukin-2 (IL-2) production. IL-2 is a cytokine that plays an important role in adaptive immune responses. These responses may be modulated by xenoestrogens such as coumestrol, bisphenol A (BPA), DDT, and TCDD. In this research, we examined the effects and potential mechanisms of action of these estrogenic compounds on IL-2 production in activated CD4+ Jurkat T cells. IL-2 production was analyzed by ELISA and Western Blot. At the transcriptional level, protein expression was examined by RT-PCR. Coumestrol, DDT and TCDD (but not BPA) significantly suppressed IL-2 production in activated CD4+ Jurkat T cells, at the transcriptional and translational levels. The transcriptional suppression of IL-2 was associated with decreased protein levels of NF-κβ, an important IL-2 positive transcription factor, without affecting the expression of Iκ−Βα protein expression, an important inhibitor of NF-κβ nuclear translocation. Although the direct mechanisms of xenoestrogens modulation of the immune system remain to be elucidated, coumestrol-, DDT- and TCDD-induced suppression of IL-2 may have ramifications for our understanding of the impact of xenoestrogens on health and disease.
Cytotoxicity and Transcriptional Activation of Stress Genes in Human Liver Carcinoma (HepG2) Cells Exposed to Iprodione
Authors: Washington Teresa , Tchounwou Paul  B.
Published: October 2008

Iprodione (C13H13Cl2N3O3) is a broad spectrum dicarboximide fungicide used on a wide variety of crop diseases. It is used on vegetables, ornamentals, pome and stone fruit, root crops, cotton and sunflowers, to control a variety of fungal pests. Iprodione inhibits the germination of spores and the growth of the fungal mycelium. Experimental studies with mice have indicated that exposure to iprodione at dose levels 5 to 15 folds greater than the LOAEL for liver injury, induces microsomal enzyme activities, hepatocyte proliferation, hepatomegaly, centrilobular hypertrophy, diffuse hypertrophy, and an increase in lauric acid hydroxylation. Currently, there is no toxicological data available on human health effects associated with exposure to iprodione. In this research, we performed the MTT Assay for cell viability to assess the cytotoxicity of iprodione, and the CAT-Tox (L) assay to measure the induction of stress genes in thirteen recombinant cell lines generated from human liver carcinoma cells (HepG2). The cytotoxicity data indicated a strong concentration - response relationship with regard to iprodione toxicity. The percentages of cell viability were 100 ± 0%, 128.0 ± 41.4%, 97.5 ± 37.7%, 70.1 ± 35.4%, 33.5 ± 16.1%, and 5.1 ± 3.7% in 0, 31.3, 62.5, 125, 250, and 500 μg/mL, respectively. The LC50 was 208.3±83.3 μg/mL. Data obtained from the CAT-Tox (L) assay showed that iprodione is able to induce a significant number of stress genes in HepG2 cells. At 250 ug/mL exposure, the induction levels were 1.2 ± 0.4, 50.1 ± 17.8, 3.9 ± 1.2, 16.8 ± 7.2, 10.7 ± 0.7, 1.8 ± 0, 26.3 ± 10.0, 7.2 ± 2.4, 1.8 ± 0.0, 6.8 ± 1.3, 6.7 ± 0.5, and 4.3 ± 1.8 for CYP1A1, GSTYa, XRE, HMTIIA, c-fos, NF-kBRE, HSP70, CRE, RARE, GADD153, GADD45, and GRP78, respectively. These results indicate that the metabolism of iprodione involves Phase II biotransformation in the liver (XRE, GSTYa), and that this chemical has the potential to cause cell proliferation and/or inflammatory reactions (c-fos, NF-kB), proteotoxic effects (HSP70, GRP78), metabolic disruption (CRE), and DNA damage (GADD45, GADD153).
Liver and Renal Function Tests in Artisans Occupationally Exposed to Lead in Mechanic Village in Nnewi, Nigeria
Authors: Dioka C.  E. , Orisakwe O.  E. , Adeniyi F. A.A. , Meludu S. C.
Published: October 2008

Additives in petroleum solvents have been reported to have adverse health implications. An evaluation study on some toxicological effects of occupational exposure to petroleum products (especially petrol which contains tetraethyl lead) amongst twenty five occupationally exposed artisans and twenty five graduate students of College of Health Sciences, Nnamdi Azikiwe University, Nnewi, Nigeria as controls, was carried out using the following biochemical markers: electrolytes, urea, uric acid, inorganic phosphorus, creatinine, zinc and blood lead, as well as the activities of alanine and aspartate aminotransferases, and alkaline phosphatase. The results showed that occupational exposure of human subjects to lead in petrol increases the concentrations of uric acid (357 ± 123μ mol/L) and phosphate (1.5 ± 0.5m mol/L) in exposed subjects compared with unexposed subjects (uric acid 228 ± 105μ mol/L, phosphate 1.2 ± 0.41m mol/L; p < 0.01 in both cases). Significantly lower activities were observed for alkaline phosphatase (66 ± 18.9 iu/L). The activities of alanine aminotransferase (11.4 ± 4.0 iu/L) and aspartate aminotransferase (15.8 ± 4.4 iu/L) in occupationally exposed artisans were higher compared with unexposed subjects (alkaline phosphatase = 78 ± 22.4 iu/L alanine aminotranferase = 6.8 ± 2.7 iu/L, aspartate aminotranferase = 9.6 ± 3.5i u/L; p < 0.01 in all cases). Occupational exposure of human subjects to lead significantly increased blood lead (59.6 ± 15.9 μg/dL) and decreased plasma zinc (71.3 ± 14.4 μg/L) in exposed compared with unexposed subjects (blood lead = 35 ± 7 μg/dL, zinc = 108.4 ± 16.9 μg/dL; p < 0.01). The results indicate that occupational exposure to lead in petrol may compromise liver and renal function.
Changes in Soil Chemical Properties and Microbial Activities in Response to the Fungicide Ridomil Gold Plus Copper
Authors: Demanou Joseph , Monkiédjé Adolphe , Njiné Thomas , Foto Samuel M. , Nola Moise , Zebaze Togouet Serges H. , Kemka Norbert
Published: October 2008

The purpose of the study was to investigate changes of soil chemical and biological properties changes resulting from a single application of the fungicide Ridomil Gold plus copper (Ridomil Gold plus)(mefenoxam 6% + copper oxide 60%) at the following rates 0.25, 0.5, 1, 2, and 10 g m-2. Selected chemical properties generally differed between fungicide rates over longer incubation periods. Microbial activity indices (available N, ammonification rates and specific enzymatic systems) were more sensitive indicators of change. Values of these indicators generally increased with incubation period and decreased or increased at high rates. Significant changes in P availability occurred after 90 days of incubation at rates ≥ 1 g m-2. Incorporation of the fungicide significantly increased NH4+ levels in soil after 75 days of incubation. These changes stimulated soil microbial activity as evidenced by increased ammonification rates especially at long-term exposure. Of the enzyme activities studied, dehydrogenase and ß-glucosidase activities were the most sensitive to ridomil gold plus. This sensitivity was more pronounced with the dehydrogenase activity.
Toxicity of a Mixture of 2,4-Dichlorophenoxyacetic Acid and Mono-soduim Methanearsonate to the Red Swamp Crawfish, Procambarus clarkii
Authors: Green Rosalind  M. , Abdelghani Assaf  A.
Published: October 2008

2,4-dichlorophenoxyacetic acid and monosodium methanearsonate are often sold in commercial herbicide mixtures. Toxicity studies have been performed for each herbicide individually, but there is a dearth of information concerning the toxicity of these herbicides in a mixture. The following study examined the toxicity of a mixture of these two herbicides in the red swamp crawfish, Procambarus clarkii. 96-hour acute toxicity assays were performed to determine whether surfactant significantly altered the toxicity of these herbicides individually or in combination. Marking’s additive index was calculated to identify the interactions of the herbicide mixture. Surfactant was observed to significantly increase the toxicity of 2,4-dichlorophenoxyacetic acid and the toxicity of the herbicide mixture. The herbicide mixture alone displayed half the toxicity of the individual herbicides, but the mixture with surfactant was twice as toxic as the individual herbicides. The synergistic action of surfactant may be attributed to increased pesticide absorption across biological membranes. 2,4-dichlorophenoxyacetic acid and surfactant may also compromise gill function, increasing the sensitivity of the crawfish to herbicide toxicity. The antagonistic effects of the herbicide mixture in the absence of surfactant may be caused by competition of both herbicides for the same sites of activity.
Molecular and Cellular Mechanisms Associated with Autoimmune Diseases
Authors: Ayensu Wellington  K. , Tchounwou Paul  B. , McMurray Robert  W.
Published: October 2008

Evidence points to increases in the incidence and prevalence of several autoimmune diseases in the United States. As a result, the cost to public health from clinical management of autoimmune conditions is on the rise. The initiation and progression of autoimmune disturbances involves both genetic and environmental factors. Deficiencies in important proteins that normally participate in maintaining checks and balances within the internal milieu may render an individual prone to developing autoantibodies. Structural abnormalities or decline in normal levels of the pentraxins (serum amylase-P protein, the acute phase proteins, complement, and C-reactive proteins) have been shown to induce autoimmunity. Irregular transmission of information arising from multiple signal transduction pathways typically associated with the serine/threonine cascade routes of mitogen activating phosphorylation kinases, has also been found to induce autoimmunity. The kind of ligand/receptor interactions drives physical recruitment of different signals within the lymphocyte; these links define the quality and quantity of subsequent immune responses. CD95 or the Fas/Apo-1 and its ligand CD95L participate in regulating lymphocyte populations and therefore influence various aspects of immune responses. Mutational abnormalities resulting from synthesis of proteins by the CD95 and/or its ligand CD95L may result in alterations in the apoptotic pathways. Apoptosis may be completely inhibited, activated or partially stimulated. Modulation of apoptosis may lead to accumulation of self-antigens. Subsequently the immune system may be stimulated to react against self-molecules through lymphatic hyperplasia. This process may end up in proliferative disorders and enhanced susceptibility to autoimmune syndromes. This paper deals with mechanisms of autoimmunopathogenesis at the cellular and molecular levels. Emphasis is laid on the role of T and B cell receptor/ligand interactions, functions and malfunctions due to structural and quantitative alterations in T- B- cell cluster of antigen determinants. Genetically susceptible patients who develop spontaneous autoimmune diseases are examined and the etiological factors implicated in the initiation and subsequent dissemination of autoimmune diseases is discussed.
Association of Clinical Complications with Nutritional Status and the Prevalence of Leukopenia among Arsenic Patients in Bangladesh
Authors: Islam Laila  N. , Nabi AHM  Nurun , Rahman M  Mahfuzur , Khan Monsur  A. , Kazi Azizul  I.
Published: October 2008

This study conducted in Bangladesh reports the relationship of clinical complications with nutritional status and the prevalence of leukopenia among arsenic exposed patients living in the rural villages. A total of 115 exposed individuals diagnosed as arsenicosis patients were randomly selected from four known arsenic endemic villages, and age-matched 120 unexposed subjects were enrolled in the study program. The duration of arsenic exposure in about 37% of the patients was at least 10 yrs, while the population mean and range were 7.6 ± 5.2 yrs, and 1 – 25 yrs, respectively. The mean arsenic concentrations in the drinking water for the exposed and unexposed (control) population were 218.1 μg/L and 11.3 μg/L, respectively. The spot urine sample of the arsenicosis patients contained an average of 234.6 μg/L arsenic. Although very few patients showed elevated WBC count, 16% had leukopenia (below normal count), and the whole population had significantly low WBC count than the control subjects. Prevalences of neutropenia and lymphocytosis were observed in patients with chronic exposure to high levels of arsenic in water. The body mass index was found to be lower than 18.5, the cut-off point for malnutrition (underweight), in about 28% of the arsenicosis cases compared to 15% of the controls. The monthly income and total calorie consumption per day showed the patients were underprivileged than the controls. Arsenical symptoms and complications were more severe in the nutritionally vulnerable (underweight) patients than the overweight ones. Also, the incidences of leukopenia and anaemia were more common in the female patients who were underweight. The findings of this research demonstrate that the poor nutritional status of patients increases the complications of chronic arsenic toxicity; suggest the possibility of other sources of arsenic contamination different from drinking water in the study area; and establish a higher prevalence of leukopenia and lymphocytosis in arsenicosis patients.
Arsenic-Induced Genotoxic and Cytotoxic Effects in Human Keratinocytes, Melanocytes and Dendritic Cells
Authors: Graham-Evans Barbara , Cohly Hari , Yu Hongtao , Tchounwou Paul
Published: October 2008

Arsenical keratosis and skin cancer are among the most common health effects associated with acute and chronic exposures to arsenic. This study examines the acute and chronic dose-responses of arsenic in established human cell lines using keratinocytes (HaCaT), melanocytes (CRL1675) and dendritic cells (THP-1 + A23187). Chronic conditions were established by treating the three cell lines with at least 8 passages in 0.2 μg/mL arsenic trioxide. Cytotoxicity was assessed using the fluorescein diacetate assay after 72 hrs of exposure. Single cell gel electrophoresis (Comet assay) was used to measure DNA damage. Acute exposure to arsenic had LD10 and LD25 values of 0.38 μg/mL and 3.0 μg/mL for keratinocytes; 0.19 μg/mL and 0.38 μg/mL for melanocytes; and 0.38 μg/mL and 0.75 μg/mL for dendritic cells. Cytotoxicity assays for chronically exposed cells resulted in LD10, and LD25 values of 0.4 μg/mL and 0.8 μg/mL for keratinocytes; 0.10 μg/mL and 0.20 μg/mL for melanocytes; and 0.10 μg/mL and 1.0 μg/mL for dendritic cells. The Comet assay showed that arsenic was highly genotoxic to the three cell lines. No significant differences (p > 0.05) in DNA cleavage were observed between acute and chronic exposures. In acute exposure arsenic genotoxicity was more severe with dendritic cells while melanocytes were more sensitive to arsenic cytotoxicity. Similarly, chronically exposed dendritic cells showed the maximum genotoxic damage while melanocytes were more sensitive to arsenic cytotoxicity. In conclusion, this research shows that arsenic is dermatotoxic, showing a high degree of genotoxicity and cytotoxicity to skin cells.