Continua of interactions between pairs of atoms in molecular crystals

The electron density distributions in crystals of five previously studied DMAN complexes and five Schiff bases (two new ones) have been analysed in terms of various properties of bond critical points (BCPs) found in the pair-wise interactions in their lattices. We analysed the continua of interactions including covalent/ionic bonds as well as hydrogen bonds and all other types of weak interactions for all pairs of interacting atoms. The charge density at BCPs and local kinetic and potential energy densities vary exponentially with internuclear distance (or other measures of separation). The parameters of the dependences appear to be characteristics of particular pairs of atom types. The Laplacian and the total (sum of kinetic and potential) energy density at BCPs show similar behaviour with the dependence being of the Morse type. The components lambda1, lambda2, lambda3 of the Laplacian at BCPs vary systematically with internuclear distance according to the type of atom pair. For lambda1 and lambda2 the distribution is of the exponential type, whereas lambda3 does not seem to follow any simple functional form, consistent with previous theoretical findings. Analytical nonlinear dependences of Laplacian on charge density have been found. They agree reasonably well with those obtained by least square fit of the Laplacian to charge density data. There are four distinct regions of the [symbol: see text]2rho(BCP)/rho(BCP) space, generated by E(BCP) = 0 and G(BCP)/rho(BCP) = 1 conditions. Two regions clearly correspond to the shared-shell and closed-shell interactions and the other two to some intermediate situation.     

MWCNT‐modified Electrode for Voltammetric Determination of Allura Red and Brilliant Blue FCF in Isotonic Sport Drinks

A fast and simple electrochemical sensor is presented for the determination of allura red and brilliant blue in isotonic sport drinks, using a glassy carbon electrode modified with multi‐walled carbon nanotubes. The electrochemical behavior of the colorants was studied by cyclic and differential pulse voltammetry in 0.1 M PBS, pH 7.0. The solution pH, the amount of nanomaterial on the surface of the electrode and the accumulation time of each colorant were optimized. Under the optimal conditions, the sensor exhibited a linear response to allura red and brilliant blue with detection limits of 7 μg L^?1 and 52 μg L^?1, respectively. The sensor was applied to the analysis of commercial isotonic sports drinks that contain individual or mixed colorants, showing good sensitivity and reproducibility. The results were compared with a chromatographic method showing that the levels of colorants are low and did not show a risk for a consumer's health.     

Quantum Walks on Hypergraphs

In this work we introduce the concept of a quantum walk on a hypergraph. We show that the staggered quantum walk model is a special case of a quantum walk on a hypergraph.

     

MRI fast tree log scanning with helical undersampled projection acquisitions

Magnetic Resonance Imaging opens an alternative way to analyze wood structures using a non-destructive technology. It provides high resolution, compound-based contrast manipulation and increased data acquisition flexibility. The technique is particularly useful for tree logs, since they present several characteristics that can be used to reduce the long scan time. This study proposes a method that takes advantage of the log cylindrical symmetry, acquiring transverse 1-D projections with a helical and undersampled pattern. Linear interpolation is used to estimate the skipped data and slice images are reconstructed by filtered backprojection. The sequence is improved using selective multi-pass scanning, without major variations of the scan time. Computer simulations and experimental results show that the proposed technique can increase the scan speed by a factor of 6, while maintaining the ability to identify typical tree log characteristics.     

Evaluation of Innovative Dried Purée from Jerusalem Artichoke—In Vitro Studies of Its Physicochemical and Health-Promoting Properties

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.     

Crystal Engineering of Schiff Base Zn(II) and Cd(II) Homo- and Zn(II)M(II) (M = Mn or Cd) Heterometallic Coordination Polymers and Their Ability to Accommodate Solvent Guest Molecules

Based on solvothermal synthesis, self-assembly of the heptadentate 2,6-diacetylpyridine bis(nicotinoylhydrazone) Schiff base ligand (H₂L) and Zn(II) and/or Cd(II) salts has led to the formation of three homometallic [CdL]_n (1), {[CdL]∙0.5dmf∙H₂O}_n (2) and {[ZnL]∙0.5dmf∙1.5H₂O}_n (3), as well as two heterometallic {[Zn_0.75Cd_1.25L₂]∙dmf∙0.5H₂O}_n (4) and {[MnZnL₂]∙dmf∙3H₂O}_n coordination polymers. Compound 1 represents a 1D chain, whereas 2–5 are isostructural and isomorphous two-dimensional structures. The entire series was characterized by IR spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction and emission measurements. 2D coordination polymers accommodate water and dmf molecules in their cage-shaped interlayer spaces, which are released when the samples are heated. Thus, three solvated crystals were degassed at two temperatures and their photoluminescent and adsorption–desorption properties were recorded in order to validate this assumption. Solvent-free samples reveal an increase in volume pore, adsorption specific surface area and photoluminescence with regard to synthesized crystals.     

Multifunctional Reagents for Quantitative Proteome‐Wide Analysis of Protein Modification in Human Cells and Dynamic Profiling of Protein Lipidation During Vertebrate Development

Novel multifunctional reagents were applied in combination with a lipid probe for affinity enrichment of myristoylated proteins and direct detection of lipid‐modified tryptic peptides by mass spectrometry. This method enables high‐confidence identification of the myristoylated proteome on an unprecedented scale in cell culture, and allowed the first quantitative analysis of dynamic changes in protein lipidation during vertebrate embryonic development.