Growth of 2-methyl-4-nitroaniline (MNA) crystals by the bridgman method

Organic single crystals of 2-methyl-4-nitroaniline (MNA) up to 3 mm in diameter and 20 mm in length have been successfully grown by the Bridgman method using the purified reagent by sublimation. The crystals are transparent and yellow in colour by controlling the growth conditions. In the spectra of yellow coloured crystals no absorption peak is observed until about 450 nm. Also, the crystals of MNA have the two cleavage planes (311 ) and (010).     

Preparation and ionic conductivities of the plasticized polymer electrolytes based on poly(methyl methacrylate-co-alkali metal methacrylate)

Ionic conductivities of the polymer electrolytes prepared from the ionomer (poly(methyl methacrylate-co-alkali metal methacrylate)), lithium perchlorate, and ethylene carbonate as a plasticizer, were studied as a function of the ion content and the alkali-metal cation of the ionomer. It was possible to obtain tough films with room-temperature ionic conductivities of ∼ 10^-3 S/cm. The maximum ion conductivities of the polymer electrolytes were obtained at the ion content of 5 mol % for both Li and Na ionomer. The effects of the ion content of the ionomer on the ionic conductivities of the polymer electrolytes were mainly interpreted in terms of the characteristics of the ion aggregate formed in the polymer electrolytes. The thermal dependence of the ionic conductivity was shown to be a non-VTF pattern in some of the polymer electrolytes investigated, which is expected to be due to the presence of the ion aggregate. © John Wiley & Sons, Inc.     

Compatibility and fungal degradation of poly[(R)-3-hydroxybutyrate]/aliphatic copolyester blend

Poly[(R)-3-hydroxybutyrate] (PHB) was blended with an aliphatic copolyester, which was synthesized by the esterification of adipic acid, ethylene glycol, and lactic acid. The blend showed a single T_g, which varied systematically but convexly upwards with the composition. The growth rate of PHB spherulites, the crystallization temperature, and the equilibrium melting temperature of the blend were decreased as the amount of the copolyester was increased. Therefore, the blend system was determined to be compatible. However, the degree of crystallinity, and the enthalpies of crystallization and fusion of PHB in the blend remained almost constant, regardless of the compositional change, although the crystallization rate was decreased upon blending. No chemical change such as transesterification was observed as a result of the blending, yet there was a slight change in the crystalline morphology of PHB. The rate of fungal degradation was lowered with an increase in the copolyester content of the blend. © 1996 John Wiley & Sons, Inc.     

Miscibility of poly(ethylene terephthalate)/poly(ethylene 2,6-naphthalate) blends by transesterification

The effects of transesterification on the miscibility of poly(ethylene terephthalate)/poly(ethylene 2,6-naphthalate) were studied. Blends were obtained by solution precipitation at room temperature to avoid transesterification during blend preparation. The physical blends and transesterified products were analyzed by wide-angle x-ray scattering, differential scanning calorimetry, and nuclear magnetic resonance spectroscopy. It was found that the physical blends are immiscible and when the extent of transesterification reaches 50% of the completely randomized state, independent of blend composition, the blends are not crystallizable and show a single glass transition temperature between those of starting polymers. The interchange reactions were significantly influenced by annealing temperature and time but negligibly by blend composition. © 1996 John Wiley & Sons, Inc.     

Reaction of 4,5-dichloro-3-nitropyridazin-6-one with dimethylchloromethyleneammonium chloride

3,4,5-Trichloropyridazin-6-one, 3,4,5,6-tetrachloropyridzine and 4,5-dichloro-3-(N,N-dimethylamino)-pyridazin-6-one were synthesized from 4,5-dichloro-3-nitropyridazin-6-one and dimethylchloromethylene-ammonium chloride selectively.     

Supramolecular Phthalocyanine Assemblies for Improved Photoacoustic Imaging and Photothermal Therapy

Phototheranostic nanoplatforms are of particular interest for cancer diagnosis and imaging‐guided therapy. Herein, we develop a supramolecular approach to fabricate a nanostructured phototheranostic agent through the direct self‐assembly of two water‐soluble phthalocyanine derivatives, PcS4 and PcN4. The nature of the molecular recognition between PcS4 and PcN4 facilitates the formation of nanostructure (PcS4‐PcN4) and consequently enables the fabrication of PcS4‐PcN4 with completely quenched fluorescence and reduced singlet oxygen generation, leading to the high photoacoustic and photothermal activity of PcS4‐PcN4. In vivo evaluations suggest that PcS4‐PcN4 could not only efficiently visualize a tumor with high contrast through whole‐body photoacoustic imaging but also enable excellent photothermal therapy for cancer.     

Computational Approaches to Discover Novel Natural Compounds for SARS-CoV-2 Therapeutics

Scientists all over the world are facing a challenging task of finding effective therapeutics for the coronavirus disease (COVID-19). One of the fastest ways of finding putative drug candidates is the use of computational drug discovery approaches. The purpose of the current study is to retrieve natural compounds that have obeyed to drug-like properties as potential inhibitors. Computational molecular modelling techniques were employed to discover compounds with potential SARS-CoV-2 inhibition properties. Accordingly, the InterBioScreen (IBS) database was obtained and was prepared by minimizing the compounds. To the resultant compounds, the absorption, distribution, metabolism, excretion and toxicity (ADMET) and Lipinski's Rule of Five was applied to yield drug-like compounds. The obtained compounds were subjected to molecular dynamics simulation studies to evaluate their stabilities. In the current article, we have employed the docking based virtual screening method using InterBioScreen (IBS) natural compound database yielding two compounds has potential hits. These compounds have demonstrated higher binding affinity scores than the reference compound together with good pharmacokinetic properties. Additionally, the identified hits have displayed stable interaction results inferred by molecular dynamics simulation results. Taken together, we advocate the use of two natural compounds, STOCK1N-71493 and STOCK1N-45683 as SARS-CoV-2 treatment regime.     

A Fluorescent Sensor for Dual‐Channel Discrimination between Phosgene and a Nerve‐Gas Mimic

The ability to analyze highly toxic chemical warfare agents (CWAs) and related chemicals in a rapid and precise manner is essential in order to alleviate serious threats to humankind and public security caused by unexpected terrorist attacks and industrial accidents. In this investigation, we designed a o‐phenylenediamine‐pyronin linked dye that is capable of both fluorogenic and colorimetric discrimination between phosgene and the prototypical nerve‐agent mimic, diethyl chlorophosphate (DCP) in the solution or gas phase. Moreover, this dye has been used to construct a portable kit that can be employed for real‐time monitoring of DCP and phosgene in the field, both in a discriminatory manner, and in a simple and safe way.     

Preparation of Tin Oxide-Based Metal Oxide Particles

Tin oxide-doped hybrid particles were prepared by a wet chemical process with organic-inorganic (phenyl/silica) hybrid particles in an alcoholic solution. The phenyl/silica hybrid particles, with a diameter of ca. 790 nm were used as a new support material for tin oxide (SnO₂) particles from tin(IV) chloride. The surface of the particles was modified via nitration of aromatic groups in the particles, to promote formation of the tin oxide coating on the particles. The thickness and surface morphology of the tin oxide layer coated on the nitrated-phenyl/silica hybrid particles could be controlled by varying the tin(IV) chloride concentration and reaction time. The size and morphology of the resultant particles were investigated with field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The particles obtained were also characterised by infrared (FTIR) and solid-state ¹³C magic angle spinning nuclear magnetic resonance (¹³C-CP/MAS NMR) spectroscopy. The effect of processing parameters on the crystallinity and structure of the doped hybrids were confirmed by X-ray diffraction (XRD) patterns.     

Dynamic mechanical properties of metallic glasses

Dynamic mechanical properties of two metallic glasses, Fe₄₀Ni₄₀P₁₄B₆ and Fe₃₂Ni₃₆Cr₁₄P₁₂B₆, have been studied at frequencies ranging from 0.1 to 3 kHz and at temperatures between ? 160 and 390°C. Each of the samples exhibits an internal friction maximum at about ?20°C with activation energies of 25 and 34 kcal/mol. A possible mechanism for the low-temperature internal friction peak is suggested.