Elemental‐Sulfur‐Mediated Facile Synthesis of a Covalent Triazine Framework for High‐Performance Lithium–Sulfur Batteries

A covalent triazine framework (CTF) with embedded polymeric sulfur and a high sulfur content of 62 wt % was synthesized under catalyst‐ and solvent‐free reaction conditions from 1,4‐dicyanobenzene and elemental sulfur. Our synthetic approach introduces a new way of preparing CTFs under environmentally benign conditions by the direct utilization of elemental sulfur. The homogeneous sulfur distribution is due to the in situ formation of the framework structure, and chemical sulfur impregnation within the micropores of CTF effectively suppresses the dissolution of polysulfides into the electrolyte. Furthermore, the triazine framework facilitates electron and ion transport, which leads to a high‐performance lithium–sulfur battery.     

Qualitative properties of strongly pseudomonotone variational inequalities

Qualitative properties of strongly pseudomonotone variational inequalities such as solution existence, stability and global error bound are studied in this paper.     

Classical Dynamics Based on the Minimal Length Uncertainty Principle

In this paper we consider the quadratic modification of the Heisenberg algebra and its classical limit version which we call the β-deformed Poisson bracket for corresponding classical variables. We use the β-deformed Poisson bracket to discuss some physical problems in the β-deformed classical dynamics. Finally, we consider the (α,β)- deformed classical dynamics in which minimal length uncertainty principle is given by \( [ \hat {x} , \hat {p}] = i \hbar (1 + \alpha \hat {x}^{2} + \beta \hat {p}^{2} ) \). For two small parameters α,β, we discuss the free fall of particle and a composite system in a uniform gravitational field.     

Electrooptical and electrochemical properties of an ionic conjugated polymer,poly(2-ethynylpyridinum-N-benzoylsulfonate)

The electrooptical and electrochemical properties of a self-dopable ionic conjugated polyacetylene, poly(2-ethynylpyridinium-N-benzoylsulfonate) (PEPBS), were studied. The photoluminescence spectra of the polymer showed that the photoluminescence peak was located at 545 nm corresponding to the photon energy of 2.27 eV. The cyclic voltammograms of the polymer exhibited reversible electrochemical behaviors between the doped and undoped peaks. It was found from the dependence of the oxidation current density of the polymer on scan rate that the kinetics of the redox process was diffusion-controlled. The electrical conductivity (σ) of undoped PEPBS was 5.7 × 10⁻⁹ S/cm. The text was submitted by the authors in English.     

Effect of the polarity of silver nanoparticles induced by ionic liquids on facilitated transport for the separation of propylene/propane mixtures

The effect of ionic liquids on the formation of a partial positive charge on the surface of silver nanoparticle and its subsequent effect on facilitated olefin transport were investigated. Three different ionic liquids of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM⁺BF₄⁻), 1-butyl-3-methylimidazolium triflate (BMIM⁺Tf⁻), and 1-butyl-3-methylimidazolium nitrate (BMIM⁺NO₃⁻) were employed to control the positive charge density of the surface of silver nanoparticles. The positive charge density of the silver nanoparticles, as characterized by the binding energy of the silver atom, was in the following order: BMIM⁺BF₄⁻/Ag ? BMIM⁺Tf⁻/Ag > BMIM⁺NO₃⁻/Ag. This order was consistent with the tendency of ionic liquids to form free ions. The best separation performance for the propylene/propane mixtures was a mixed gas selectivity of 17 and a permeance of 7 GPU through a composite membrane consisting of BMIM⁺BF₄⁻/Ag. A better separation performance for olefin/paraffin mixtures was observed with a higher positive charge density of the silver nanoparticles. It was therefore concluded that facilitated olefin transport was a direct consequence of the surface positive charge of the silver nanoparticles induced by ionic liquids.     

Osmotic pressure and structures of monodisperse ordered foam

We present an experimental and numerical study of the osmotic pressure in monodisperse ordered foams as a function of the liquid fraction. The data are compared to previous results obtained for disordered monodisperse and polydisperse concentrated emulsions. Moreover, we report a quantitative investigation of the transition from a bubble close packing to a bcc structure as a function of the liquid volume fraction. These findings are discussed in the context of theoretical models that have been proposed in the literature.     

Reduction potential and oxidation catalysis of vanadium-containing H6+x P2Mo18−x V x O62 Wells-Dawson heteropolyacid (HPA) catalysts

Vanadium-containing H_6+x P₂Mo_18?x V _x O₆₂ (x=0?3) Wells-Dawson heteropolyacid (HPA) catalysts were prepared. The successful formation of the Wells-Dawson HPAs was confirmed by FT-IR and ICP-AES analyses. The reduction potential of the H_6+x P₂Mo_18?x V _x O₆₂ (x=0?3) catalysts was determined by temperature-programmed reduction measurements. The Wells-Dawson HPA catalysts were applied to the vapor-phase oxidation of methacrolein and benzyl alcohol. The reduction potential, conversion of methacrolein, and conversion of benzyl alcohol showed volcano-shaped curves with respect to vanadium substitution, and decreased in the order of H₈P₂Mo₁₆V₂O₆₂>H₇P₂Mo₁₇V₁O₆₂>H₉P₂Mo₁₅V₃O₆₂>H₆P₂Mo₁₈O₆₂. A correlation between reduction potential and catalytic activity clearly showed that the conversion was monotonically increased with increasing reduction potential of the HPA catalyst in both oxidation reactions.     

Biodegradable microspheres containing poly(epsilon-caprolactone)-Pluronic block copolymers for temperature-responsive release of proteins

Temperature-responsive microspheres were fabricated for the purpose of releasing protein in responsive to surrounding temperature changes. Temperature-responsive polymer, Pluronic was synthesized into block copolymers of poly(epsilon-caprolactone)-Pluronic with two different chain lengths of poly(epsilon-caprolactone). Microspheres loaded with proteins were prepared by a W/O/W emulsion method. The surface morphology was examined by scanning electron microscopy, showing that microspheres with diblock copolymers had porous structures due to hydrophilicity of Pluronic blocks. After incubating the microsphere at 37 degrees C for 7 days, temperature-responsive protein release was monitored with alternating temperature changes between 20 and 37 degrees C. The protein release was attenuated when the microsphere was incubated at 20 degrees C but the release rate was recovered at 37 degrees C, confirming variable release rate according to the temperature changes. The variable release rate of protein was dependent on the length of poly(epsilon-caprolactone) blocks attached to Pluronic.     

Quantitative determination of progesterones and corticosteroids in human urine using gas chromatography/mass spectrometry: application to pelvic organ prolapse patients

A quantitative analytical method using gas chromatography/mass spectrometry (GC/MS) to determine urinary concentrations of eight progesterones and corticosteroids has been developed. After enzymatic hydrolysis with beta-glucouronidase/arylsulfatase, urine samples were extracted by simple one-step solid-phase extraction. Obtained extracts were derivatized with a mixture of N-methyl-N-(trimethylsilyl)trifluoroacetamide/ammonium iodide/dithiothreitol and determined by GC/MS in selected ion monitoring mode to increase the sensitivity. d(4)-Cortisol and d(9)-progesterone were used as internal standards for two different steroid groups. The linear correlation coefficient was in the range of 0.9913 to 0.9998 and recoveries were over 80% for all compounds. Precision and accuracy were in the range of 0.9-18.1 and 84.1-118.7%, respectively. The limit of quantitation (LOQ) was 10 ng/mL for 11-deoxycorticosterone and 21-deoxycortisol and 5 ng/mL for all other analytes. The developed method was successfully applied on pelvic organ prolapsed patients (n = 10, age: 67.9 +/- 4.9) and post-menopausal (n = 10, age: 63.6 +/- 5.5) control women. Urinary levels of most progesterones and corticosteroids except 11-deoxycorticosterone decreased but only that of 17 alpha-hydroxyprogesterone significantly decreased in patients compared with the control groups. Thus, it is concluded that progesterones could be a factor in the pathogenesis of pelvic organ prolapse, and, among them, 17 alpha-hydroxyprogesterone could be a biomarker for pelvic organ prolapse.     

Structural identification of novel glucoside and glucuronide metabolites of (-)-epigallocatechin-3-gallate in mouse urine using liquid chromatography/electrospray ionization tandem mass spectrometry

(-)-Epigallocatechin-3-gallate (EGCG), the most abundant and most biologically active polyphenolic compound in tea, has been proposed to have many health beneficial effects. The metabolic fate of EGCG, however, is not well understood. In the present study, we identified a novel EGCG metabolite, 7-O-beta-D-glucopyranosyl-EGCG-4'-O-beta-D-glucupyranoside, in a mouse urine sample using liquid chromatography/electrospray ionization tandem mass spectrometry. The structure of this metabolite was confirmed by analyzing the MSn (n = 1-4) spectra as well as comparing the MS/MS spectra of its product ions with those from EGCG and EGCG-4'-O-beta-D-glucupyranoside standards. To our knowledge, this is the first report of the identification of a glucoside metabolite of EGCG in mammals. Our results indicate that glucosidation represents a novel pathway in the metabolism of EGCG in mice.