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In this note, we give a self-contained presentation of the POAV2 theory developed by Haddon to study the alignment of π-orbitals along a non-planar molecule. The classical POAV theory is purely geometric instead of the POAV2 which includes more physics in the computations. We compare the results obtained from the POAV2 and POAV theory. We prove that the difference between the two quantities is in most of the cases negligible. As a consequence, the POAV theory is sufficient for most of the purposes concerning the description of the local π-system of a molecule. [ABSTRACT FROM AUTHOR]

We study the positivity of solutions of a class of semi-linear parabolic systems of stochastic partial differential equations by considering random approximations. For the family of random approximations we derive explicit necessary and sufficient conditions such that the solutions preserve positivity. These conditions imply the positivity of the solutions of the stochastic system for both Itô's and Stratonovich's interpretation of stochastic differential equations. [ABSTRACT FROM AUTHOR]

Competing Interests: The authors have no conflicts of interest to report.

Gender is an important risk factor for adverse drug reactions. Women report significantly more adverse drug reactions than men. There is a growing consensus that gender differences in drug PK is a main contributor to higher drug toxicity in women. These differences stem from physiological differences (body composition, plasma protein concentrations, and liver and kidney function), drug interactions, and comorbidities. Contrast agents are widely used to enhance diagnostic performance in computed tomography and magnetic resonance imaging. Despite their broad use, these contrast agents can lead to important adverse reactions including hypersensitivity reactions, nephropathy, and hyperthyroidism. Importantly, female gender is one of the main risk factors for contrast agent toxicity. As these adverse reactions may be related to gender differences in PK, this perspective aims to describe distribution and elimination pathways of commonly used contrast agents and to critically discuss gender differences in these processes., Competing Interests: The authors declare no competing financial interest., (© 2023 American Chemical Society.)

Herein, we deeply detail for the very first time mathematical concepts behind the generation of helical molecular orbitals (MOs) for linear chains of atoms. We first give a definition of helical MOs and we provide an index measuring how far a given helical states is from a perfect helical distribution. Structural properties of helical distribution for twisted N ${\left[N\right]}$ -cumulene and cumulene version of Möbius systems are given. We then give some simple structural assumptions as well as symmetry requirements ensuring the existence of helical MOs. Considering molecules which do not admit helical MOs, we provide a first way to induce helical states by the breaking of symmetries. We also explore an alternative way using excited conformations of given molecules as well as different electronic multiplicities., (© 2023 Wiley-VCH GmbH.)

The pyramidalization angle and spherical curvature are well-known quantities used to characterize the local geometry of a molecule and to provide a measure of regio-chemical activity of molecules. In this paper, we give a self-contained presentation of these two concepts and discuss their limitations. These limitations can bypass, thanks to the introduction of the notions of angular defect and discrete Gauss curvature coming from discrete differential geometry. In particular, these quantities can be easily computed for arbitrary molecules, trivalent or not, with bond of equal lengths or not. All these quantities have been implemented. We then compute all these quantities over the Tománek database covering an almost exhaustive list of fullerene molecules. In particular, we discuss the interdependence of the pyramidalization angle with the spherical curvature, angular defect, and hybridization numbers. We also explore the dependence of the pyramidalization angle with respect to some characteristics of the molecule, such as the number of atoms, the group of symmetry, and the geometrical optimization process.

Pantothenate kinase (PanK) catalyzes the transformation of pantothenate to 4'-phosphopantothenate, the first committed step in coenzyme A biosynthesis. While numerous pantothenate antimetabolites and PanK inhibitors have been reported for bacterial type I and type II PanKs, only a few weak inhibitors are known for bacterial type III PanK enzymes. Here, a series of pantothenate analogues were synthesized using convenient synthetic methodology. The compounds were exploited as small organic probes to compare the ligand preferences of the three different types of bacterial PanK. Overall, several new inhibitors and substrates were identified for each type of PanK., (Copyright © 2018 Elsevier Ltd. All rights reserved.)