Surface reconstruction of Pt–Sn nanoparticles supported on Al2O3 in the presence of carbon monoxide

Research on Chemical Intermediates - FTIR spectroscopy and volumetric measurements are used to study the adsorption of CO (mainly 1% CO/He) in the temperature range 300–713 K on a...     

Structural basis of pyrazolopyrimidine derivatives as CAMKIIδ kinase inhibitors: insights from 3D QSAR,docking studies and in silico ADMET evaluation

Ca²⁺/calmodulin-dependent protein kinase II (CAMKIIδ) belongs to the serine/threonine kinase family, which is involved in a broad range of cellular events in cell survival and proliferation as well as a number of other signal transduction pathways. Thus, it is regarded a promising target for treatment of cancers. In the present paper, a three-dimensional quantitative structure–activity relationship and molecular docking were applied to investigate a series of new CAMKIIδ inhibitors of pyrazolopyrimidine derivatives. The determination coefficient (R²) and leave-one-out cross-validation coefficient (Q²) of CoMSIA model are 0.676 and 0.956, respectively. The predictive ability of this model was evaluated by the external validation using a test set of eight compounds with a predicted determination coefficient \(R^{ 2}_{\text{test}}\) of 0.80, besides the mean absolute error of the test set was 0.328 log units. Docking results are in concordance with CoMSIA contour maps, gave the information for interactive mode exploration. Based on those satisfactory results, newly designed molecules were predicted with highly potent CAMKIIδ inhibitory activity, additionally, they have showed promising results in the preliminary in silico ADMET evaluations. This study could expand our understanding of pyrazolopyrimidine derivatives as inhibitors of CAMKIIδ and would be of great help in lead optimization for early drug discovery of highly potent CAMKIIδ inhibitors.     

Enzymatic detoxification of jojoba meal and effect of the resulting meal on food intake in rats

When defatted jojoba meal is used as animal food, it causes food-intake reduction and growth retardation. Detoxification procedures by chemical, microbiological, and solvent extraction methods are reported by several authors. Here we report a successful detoxification of jojoba meal using enzymes. We establish reaction conditions that yield new meal which has the same nutritional qualities in proteins as the original meal. The enzymatic reaction gives rise to one major compound to which the structure of an amide is assigned on the basis of IR, 1H and 13C NMR spectra. The effect of the resulting jojoba meal on the food intake in rats is checked. In contrast, the detoxified meal containing the amide derivatives shows no toxicological activity since rats receiving oral administration of the obtained meal show normal growth. Thus, it is expected that this meal could be used as an animal feed ingredient.     

Positive Elements and Automatic Continuity of Algebra Morphisms

We use positive elements of Hermitian algebras to give results on automatic continuity of algebra morphisms. Consequences and applications are also given.      

Optimization of a liquid chromatography ion mobility-mass spectrometry method for untargeted metabolomics using experimental design and multivariate data analysis

High-resolution mass spectrometry coupled with pattern recognition techniques is an established tool to perform comprehensive metabolite profiling of biological datasets. This paves the way for new, powerful and innovative diagnostic approaches in the post-genomic era and molecular medicine. However, interpreting untargeted metabolomic data requires robust, reproducible and reliable analytical methods to translate results into biologically relevant and actionable knowledge. The analyses of biological samples were developed based on ultra-high performance liquid chromatography (UHPLC) coupled to ion mobility - mass spectrometry (IM-MS). A strategy for optimizing the analytical conditions for untargeted UHPLC-IM-MS methods is proposed using an experimental design approach. Optimization experiments were conducted through a screening process designed to identify the factors that have significant effects on the selected responses (total number of peaks and number of reliable peaks). For this purpose, full and fractional factorial designs were used while partial least squares regression was used for experimental design modeling and optimization of parameter values. The total number of peaks yielded the best predictive model and is used for optimization of parameters setting.     

Nanoporous magnets of chiral and racemic [{Mn(HL)}2Mn{Mo(CN)7}2] with switchable ordering temperatures (TC = 85 K <--> 106 K) driven by H2O sorption (L = N,N-dimethylalaninol)

Molecule-based solids represent a rare opportunity to combine, adjust, and interrelate structural and physical functionalities to develop multifunctional materials. Here we report on a series of porous supramolecular magnets whose magnetic properties are related to their sorption state. A family of magnets of the formula [{Mn(HL)(H2O)}2Mn{Mo(CN)7}2].2H2O have been obtained by assembling the heptacyano-metalate building unit {Mo(CN)7}4- with Mn(II) in the presence of protonated N,N-dimethylalaninol (L) as ligand, the latter being either as a racemic mixture or as a chiral R- or S-enantiomer. The resulting magnets possess an open framework structure and exhibit a TC with a switching behavior (TC = 85 K <--> 106 K) as a function of the hydration state. Moreover, chiral magnets are formed with the optically active ligands. The H2O and gas (N2, CO2, CO) sorption features, the magnetic behavior of both the hydrated and dehydrated magnets, and the crystal structures of the hydrated chiral (S) and racemic magnets are described.     

New insights into the development of ordered structure in poly(ethylene terephthalate), II Results from transmission infrared spectroscopy of thin films

To complement our earlier work involving external reflection infrared spectroscopy of PET, a set of thin PET films with different crystalline structures (amorphous, strain-induced crystallinity, thermally induced crystallinity) was prepared and analyzed in detail in the transmission mode. In analogy with the reflection work, factor analysis was used to generate three basis spectra corresponding to three distinct structures: G = an arrangement involving gauche glycol conformers and disordered terephthalate groups; TX = an arrangement involving trans glycol conformers and disordered terephthalate groups (probably a mixture of cis and trans conformers); and TC = the all-trans arrangement found in the true crystalline phase. The TX structure is believed to play an important role in the widely reported “intermediate” phase of PET, which is particularly significant in cold-drawn samples. The transmission spectra confirm the validity of the reflection spectra and also provide more detailed information. In addition, analysis of two biaxially oriented industrial films has provided further information on the geometry of certain vibrational modes. Overall, the results lead to a better understanding of the complex crystalline structure of PET and its relationship to the infrared spectrum.     

Effects of Geomaterial-Originated Fillers on Microstructure and Mechanical/Physical Properties of α- and β-Chitosan-Based Films

Edible films and coatings with good mechanical/physical properties are highly required for carrying medical substances and food packaging. So, solvent-cast films of α- or β-chitosan filled with palygorskite, montmorillonite or geopolymer-containing material (GCM), were prepared, and the effects of their clay contents (up to 50 wt.%) on the mechanical/physical properties were assessed. The microstructure of the films was investigated using FT-IR spectroscopy, SEM and thermal analysis. The results showed that, except for the films composed of GCM and β-chitosan, the mechanical properties of the films with limited (up to 5 wt.%) to moderate (5–25 wt.%) amounts of fillers increased as a result of the attractive electrostatic forces formed between the fillers and chitosan functional groups (–NH₃⁺, CH₂OH and NHCOCH₃). However, due to the occurrence of coarse aggregates, the strength of filler-rich films declined. The addition of fillers led to an increase in porosity and water absorption of the films, but it had irregular effects on their wettability and water vapor transmission rate. These observations as well as the thermal stability of the films were discussed in relation to the characterization results.