Impact of ambient conditions on the minor nutrients content in spirulina "Arthrospira platensis" (AP) extracted from Lake Chad revealed by fluorescence spectroscopy coupled with chemometric methods.

In this study, the technique of fluorescence spectroscopy coupled with chemometric methods is used to analyse samples of Lake Chad Spirulina "Arthrospira platensis" (AP), either harvested and conditioned by using the traditional method at different seasons or industrially processed. The content of minor fluorescent nutrients is investigated. To this end, fluorescence excitation-emission matrices (EEMs) of 46 AP samples are recorded in aqueous solution.

Binding of Mammea A/AA (MA) to calf thymus DNA revealed by the ratiometric absorbance of MA in the UV-visible range molecular dynamic simulations and TD-DFT calculations.

The anti-proliferative activity of on a variety of cancer cells was previously demonstrated. This work strives to understand the mechanisms by which exerts this biological activity. Thereafter, the binding of to calf thymus DNA was studied by monitoring the change in the UV-visible absorbance of .

Impact of temperature and sunlight exposition on locally brewed beers composition revealed by fluorescence spectroscopy coupled with chemometric methods.

Fluorescence excitation-emission matrix (EEM) and synchronous scanning fluorescence (SF), coupled with parallel factor (PARAFAC) analysis, principal component analysis (PCA) and Linear discriminant analysis (LDA) methods were used to differentiate 49 lager beer samples and monitor the effects of temperature and sunlight exposition on their composition. EEMs were decomposed into independent fluorescent components. The beer samples were characterized by the presence of excitation/emission (exc/em) peaks at 290/350, 315/345, 340/410, 375/455, 360/420, 400/460, and 437/525 nm, which were ascribed, according to the known beer fluorescent components, respectively to aromatic amino acids, vitamin B6 (pyridoxal), vitamin B6 (pyridoxic acids), vitamin B3, iso-α-acids, vitamin B1, and vitamin B2.

Antioxidant Properties of Lapachol and Its Derivatives and Their Ability to Chelate Iron (II) Cation: DFT and QTAIM Studies.

The elucidation of the complexation of lapachol and its derivatives to Fe cation has been done using the density functional theory (DFT). This complexation has been limited to bidentate and tridentate to Fe cation. Geometry optimizations have been implemented in gas and solution phase (water, acetonitrile, chlorobenzene, benzene, and toluene) for ligands at B3LYP/6-311++G (d,p) level of theory using B3LYP/6-31+G(d,p) optimized data as starting point.

Electronic transitions and ESIPT kinetics of the thienyl-3-hydroxychromone nucleobase surrogate in DNA duplexes: a DFT/MD-TDDFT study.

The fluorescent nucleobase surrogate M (2-thienyl-3-hydroxychromone fluorophore) when imbedded in DNA opposite an abasic site exhibits a two colour response highly sensitive to environment changes and base composition. Its two colour emission originates from an excited state intramolecular proton transfer (ESIPT), which converts the excited normal N* form into its T* tautomer. To get deeper insight on the spectroscopic properties of M in DNA duplexes, quantum chemical calculations were performed on M stacked with different base pairs in model trimers extracted from MD simulations.

Dynamics of kink-dark solitons in Bose-Einstein condensates with both two- and three-body interactions.

The matter-wave solutions of Bose-Einstein condensates with three-body interaction are examined through the one-dimensional Gross-Pitaevskii equation. By using a modified lens-type transformation and a further extension of the tanh-function method we obtain the exact analytical solutions which describe the propagation of kink-shaped solitons, anti-kink-shaped solitons, and other families of solitary waves. We realize that the shape of a kink solitary wave depends on both the scattering length and the parameter of atomic exchange with the substrate.