it is well known that the chemical behavior of a compound is dependent upon the structure of itsmolecules. quantitative structure – activity relationship (qsar) studies and quantitative structure –property relationship (qspr) studies are active areas of chemical research that focus on the nature ofthis dependency. topological indices are the numerical value associated with chemical constitution...

An l-sequence is defined by an = lan−1 − an−2, with initial conditions a0 = 0, a1 = 1. These l-sequences play a remarkable role in partition theory, allowing l-generalizations of the Lecture Hall Theorem [7, 8] and Euler’s Partition Theorem [8, 26]. These special properties are not shared with other sequences, such as the Fibonacci sequence, defined by second-order linear recurrences. The l-seq...

This work presents the abilities in estimation and prediction of the octanol–water partition coefficient of some para-substituted phenols through the integration of complex structures information by the use of an original molecular descriptors family on the structure–property relationship approach. The proposed approach uses the complex information obtained from para-substituted phenols structu...

An assessment was made of the in situ bioaccumulation of 13 polycyclic aromatic hydrocarbons (PAHs) in freshwater isopods in relation to their partitioning between sediments, particulate matter (>0.7 µm), and dissolved phases in eight different water systems of The Netherlands. Large differences in total (Gamma PAHs) concentrations and in relative abundance of individual PAHs were observed betw...

BACKGROUND Contrast enhanced cardiovascular magnetic resonance (CMR) with T1 mapping enables quantification of diffuse myocardial fibrosis. Various factors, however, can interfere with T1 measurements. The purpose of the current study was to assess the effect of co-medication with a typical protein binding drug (ibuprofen) on T1 values in vitro and in vivo. METHODS 50 vials were prepared with...

1. Introducing the birank. A partition is defined as being a nonincreasing sequence of positive integers, λ = (λ1,λ2, . . . ,λr ). The set of all partitions, which includes the empty partition ∅, is denoted by . The sum of the parts of a given partition is called the weight of the partition, wt(λ) = λ1+λ2+···+λr . It is standard notation to write (z;q)∞ := ∏ t≥0(1−zq) and p−k(n) for the coeffic...

Chloroform, bromodichloromethane, chlorodibromomethane, and bromoform comprise the trihalomethanes, a group of widespread and mildly lipophilic compounds that result from water chlorination and other sources. Many animal studies show the chronic toxicity and carcinogenicity of these compounds, and recent work has demonstrated the importance of both ingestion and inhalation exposure pathways. Th...

Log Kow values for 14 heterocyclic nitrogen compounds (by traditional shake-flask method) were reported. Reverse phase–high-performance liquid chromatography (RP-HPLC) method and three estimation models—linear solvation energy relationship, molecular connectivity indices (MCIs), and quantum chemical descriptors—were used to study the partition mechanism and to establish the correlations of the ...

Polydimethylsiloxane (PDMS) is commonly used as the coated polymer in the solid phase microextraction (SPME) technique. In this study, the partition coefficients of organic compounds between SPME/PDMS and the aqueous solution were compiled from the literature sources. The correlation analysis for partition coefficients was conducted to interpret the effect of their physicochemical properties an...

Abstract. Planar solidification from an undercooled melt has been considered using the phase-field model. The solute and the phase fields have been found in the limit of small impurity concentration. These solutions in the limit of vanishing velocity of the interface motion give the equilibrium partition coefficient and the liquidus slope. Asymptotic expansions for the solute and for the phase ...