Simultaneous determination of thirteen main components and identification of eight major metabolites in Xuebijing Injection by UPLC/Q-TOF

An ultra performance liquid chromatographic method was used for the simultaneous identification and quantification of thirteen main components in Xuebijing Injection, including uridine, gallic acid, guanosine, danshensu, protocatechualdehyde, oxypaeoniflorin, hydroxysafflor yellow A, paeoniflorin, ferulic acid, safflor yellow A, senkyunolide I, senkyunolide H and salvianolic acid B. The chromatographic separation was performed on an Acquity UPLC BEH C₁₈ column (1.7-μm, 2.1 × 100 mm, i.d.) with a gradient elution of acetonitrile and 0.2% acetic acid at a flow rate of 0.4 mL/min. The method was validated for linearity (r ² > 0.9990), intra- and inter-day precision (RSD < 1.94%), accuracy (91.8–99.7%), recovery (96.8–103.8%), limits of detection (0.16–8.0 ng), and limits of quantification (0.54–26.8 ng). At least eight metabolites in prototype were found in rat plasma and urine after intravenous injection of 4 mL/kg doses of Xuebijing Injection. The proposed method could be utilized to qualify and control Xuebijing Injection to ensure its safety and efficacy in application.     

Cloning,Heterologous Expression,and Characterization of the Gene Cluster Required for Gougerotin Biosynthesis

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Highlights? The complete gougerotin biosynthetic gene cluster is cloned ? Heterologous production of gougerotin is accomplished in S. coelicolor M1146 ? Biosynthetic pathway is proposed based on bioinformatics, genetic, and chemical analyses ? Preliminary data support an uncommon enzymatic reaction for peptide bond formation     

Study on the structure and reactivity of COREX coal

COREX is the primary process in the current smelting reduction method. The process has strict coal quality standards. Combustion processes of coal used in the COREX operating system were analyzed using a synchronous thermogravimetric analyzer combined with a mass spectrometer. The microcosmic structure and macerals were observed by an electronic scanning microscope. The qualitative and quantitative determinations of oxygen functional groups, such as phenolic hydroxyl, carboxyl, carbonyl, and methoxy groups were detected by the Fourier Transform Infrared spectrometer (FT-IR) and through chemical analysis methods. In addition, the evolution of the chemical structure and transformation mechanism of organic oxygen functional groups during COREX coal combustion have been thoroughly investigated. This study proposes a new coal-requirement index system and coal blending method, which will increase the expansion of coal selection and decrease the overall usage of coal during COREX.     

Comparative pyrolysis upcycling of polystyrene waste: thermodynamics, kinetics, and product evolution profile

Pyrolysis is one important way to treat polystyrene waste and upcycle it into useful materials. A comparative pyrolysis study of virgin polystyrene (VPS) and two types of commonly used polystyrene products, expanded polystyrene (EPS) and polystyrene container (CPS) was carried out. Various values were found in the thermodynamic study and kinetic study of VPS, EPS, and CPS pyrolysis, suggesting distinct thermal degradation characteristics of these materials. The energy barrier order of the pyrolysis processes was EPS, CPS, VPS, showing activation energy of 230, 219, and 145 kJ mol^?1, respectively. The order of amount of heat absorbed was EPS, CPS, VPS, with enthalpy of 224, 213, and 139 kJ mol^?1, respectively. The reaction favorability order was EPS, CPS, and VPS with Gibbs free energy of 118, 132, and 210 kJ mol^?1, respectively. Thermogravimetric analysis indicated the use of high heating rate would increase the reaction rate and shorten the reaction time. Product evolution profiles showed that VPS and CPS pyrolysis produced mainly aromatics, while EPS pyrolysis produced aromatics at the initial phase of the reaction and aliphatic hydrocarbon at the latter phase. The diverse pyrolysis behaviors of VPS, EPS, and CPS demonstrated that an examination on different polystyrene materials was desired to optimize the pyrolysis conditions and product distribution, and thus benefit the process of valuable materials recovery.     

Effect of Co substitution for Ni on the microstructure and electrochemical properties of La-R-Mg-Ni-based hydrogen storage alloys

Hydrogen storage alloys La_0.63Gd_0.2?Mg_0.17Ni_3.35?x Co _x Al_0.15 (x?=?0, 0.1, 0.3, 0.5, 1.0, 1.5, 2.0) were prepared by induction melting followed by annealing treatment in argon atmosphere. The electrochemical properties of La_0.63Gd_0.2?Mg_0.17Ni_3.35?x Co _x Al_0.15 (x?=?0, 0.1, 0.3, 0.5, 1.0, 1.5, 2.0) alloy electrodes depended on the alloy structure type. XRD patterns and EPMA showed that the alloys consisted of Ce₂Ni₇-type (Gd₂Co₇-type), CaCu₅-type, Pr₅Co₁₉-type, and PuNi₃-type phase structure. Pr₅Co₁₉-type and Ce₂Ni₇-type phase increased with the increase of Co content x. However, CaCu₅-type phase firstly decreased then increased as Co content increased. Rietveld analysis showed that the c-axis lattice parameters and cell volumes of the component phases increased with increasing Co content. The electrochemical measurements showed that as the Co content increased, the maximum discharge capacity and the cyclic stability of the annealed alloys both first increased and then decreased. The La_0.63Gd_0.2?Mg_0.17Ni_3.05Co_0.3Al_0.15 alloy electrode exhibited the maximum discharge capacity (392.92 mAh/g), and La_0.63Gd_0.2?Mg_0.17Ni_1.85Co_1.5Al_0.15 alloy electrode showed the best cyclic stability (S₁₀₀?=?96.1 %). The electrochemical kinetics studies indicate that La_0.63Gd_0.2?Mg_0.17Ni_1.85Co_1.5Al_0.15 exhibited a higher rate dischargeability (HRD₉₀₀?=?86.3 %). Electrochemical analyses showed that the control process of alloy electrode reaction is charge-transfer rate in surface film of alloy.     

Surfacial carbonized palygorskite as support for high-performance Pt-based electrocatalysts

Pt nanoparticles deposited on a low-cost, surfacial, carbonized palygorskite (Pt/C-PLS) prepared by carbonizing sucrose were evaluated as a methanol oxidation catalyst for direct methanol fuel cells. Transmission electron microscopy and Fourier transfrom infrared spectrophotometry analyses revealed that carbon was formed on the surface of PLS and that free silica presented in the C-PLS support. The catalytic activity of methanol oxidation of Pt/C-PLS was higher than that of Pt/C, and the former catalyst had better CO tolerance.