Chemical modification of nanocrystalline cellulose for improved interfacial compatibility with poly(lactic acid)

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Electrochemical Properties of N-Methyl- and N-Phenyl-2,4,6-Triphenylpyridium Perchlorate

Russian Journal of Electrochemistry - The electrochemical properties of N-methyl- and N-phenyl-2,4,6-triphenylpyridinium perchlorates were studied by cyclic voltammetry (CV). The substituent at the...     

Recent Advances in Mechanically Robust and Stretchable Bulk Heterojunction Polymer Solar Cells

Organic bulk heterojunction solar cells are promising candidates as future photovoltaic technologies for large‐scale and low‐cost energy production. It is, therefore, not surprising that research on the design and preparation of these types of organic photovoltaics has attracted a lot of attention since the last two decades, leading to constantly growing values of energy conversion and efficiency. Combined with the possibility of a large‐scale production via roll‐to‐roll printing techniques, bulk heterojunction solar cells enable the fabrication of conformable, light‐weight and flexible light‐harvesting devices for point‐of‐use applications. This perspective review will highlight the recent advances toward mechanically robust and intrinsically stretchable bulk heterojunction solar cells. Mechanically robust fullerene‐based and all‐polymer devices will be presented, as well as a comprehensive overview of the recent challenges and characterization techniques recently developed to overcome some of the challenges of this research area, which is still in its infancy.     

Catalytic and Noncatalytic Ammonolysis of Polyfluorinated 1,3-Dichlorobenzenes

Reactions of 1,3-dichlorotetrafluorobenzene and 1,3-dichloro-2,4,6-trifluorobenzene with aqueous ammonia in the presence and in the absence of copper(I) salt lead to fluorine replacement by amino group in the para and ortho positions with respect to the chlorine atom. Ammonolysis of the resulting chloropolyfluoroanilines in the absence of a catalyst involves replacement of fluorine atom in the meta position with respect to the amino group. In the presence of copper(I) salt, catalytic aminodechlorination occurs at the para and ortho positions with respect to the amino group introduced in the first stage.     

Single-step radiofluorination of peptides using continuous flow microreactor

18F radiolabelling of peptides bearing two different prosthetic groups was successfully conducted in a continuous flow microfluidic device for the first time. Radiochemical yields were dependent on precursor concentration, reaction temperature and flow rate. The choice of leaving group had a dramatic influence on the reaction outcome. Rapid reaction optimization was possible.     

2,3-unsubstituted chromones and their enaminone precursors as versatile reagents for the synthesis of fused pyridines

A divergent and regioselective approach to fused pyridines was developed through formal [3 + 3] cyclocondensations from simple 2,3-unsubstituted chromones or their enaminone precursors.     

Sorption—spectrophotometric and visual test determination of trace silicon as an ion associate of 12-molybdosilicate with crystal violet

The adsorption of the ion associate (IA) of the heteropoly anion (HPA) of β-SiMo₁₂O₄₀⁴ with Crystal Violet (CV) on polyurethane foams (PUF) was studied; the conditions of HPA formation and adsorption as an IA with CV were optimised. The calculated adsorption capacity of PUF toward IA and the constant of adsorption, 0.77 μmol/g and 1.3 × 10⁶ L/mol, respectively, were determined from the linearized Lang-muirs’s adsorption isotherm. A procedure was developed for the sorption-spectrophotometric and visual test determination of silicon; C_min = 2 × 10^-8 M. The procedures were validated on examples of drinking, distilled, and mineral waters.     

Gas chromatography determination of trace of biomarkers of mustard agent and some organophosphoric toxic agents in urine

A procedure has been developed for the determination of thioglycol, 1,1′-sulfonyl-bis[2-(methylsulfonyl)-ethane], 1-methylsulfonyl-2-[2-(methylthio)ethylsulfonyl]ethane (biomarkers of mustard agent) and methylphosphonic acid, O-ethylmethylphosphonic acid, O-isopropylmethylphosphonic acid, and O-pinacolyl methylphosphonic acid (biomarkers of organophosphoric toxic agents) in urine. The procedure includes the recovery of components by liquid extraction, derivatization, separation by gas-liquid chromatography, and detection by flame-photometric and mass spectral detectors. The procedure has been applied to the analysis of samples of artificial urine by the standard addition method.     

Selenium: An Antioxidant with a Critical Role in Anti-Aging

Aging is characterized by an imbalance between damage inflicted by reactive oxygen species (ROS) and the antioxidative defenses of the organism. As a significant nutritional factor, the trace element selenium (Se) may remodel gradual and spontaneous physiological changes caused by oxidative stress, potentially leading to disease prevention and healthy aging. Se is involved in improving antioxidant defense, immune functions, and metabolic homeostasis. An inadequate Se status may reduce human life expectancy by accelerating the aging process or increasing vulnerability to various disorders, including immunity dysfunction, and cancer risk. This review highlights the available studies on the effective role of Se in aging mechanisms and shows the potential clinical implications related to its consumption. The main sources of organic Se and the advantages of its nanoformulations were also discussed.     

The local geometry of Carnot manifolds at singular points

In this paper we study the local geometry of Carnot manifolds in a neighborhood of a singular point in the case when horizontal vector fields are 2M-smooth. Here M is the depth of a Carnot manifold.