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  • Author or Editor: Li Xu x
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Abstract  

The recovery of uranium(VI) from chloride solution using a liquid emulsion membrane (LEM) technique was studied. The emulsion is constituted by the quaternary salt of benzyloctadecyldimethyl ammonium chloride (BODMAC, R4NCl) as a carrier, kerosene as organic diluent, Span 80 as emulsifying agent and 0.5 mol/l Na2CO3 as stripping phase. The important variables affecting the LEM permeation process such as the concentrations of extractant, internal strip phase, types of organic diluent, and the presence of magnesium chloride or magnesium sulfate were investigated. It was found that, at a given condition, the maximum extraction rate of uranium(VI) reached 80%. The emulsion was stable at low pH in the presence of certain amounts of electrolytes such as NaCl and MgCl2.

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The aim of this study was to investigate postprandial effects of two Chinese liquors on s elected cardiovascular disease risk factors in humans. Sixteen healthy men were randomized into three groups in a three-way crossover study: tea-flavor liquor (TFL), traditional Chinese liquor (TCL) and water control (WC). Every subject consumed 60 mL of either liquor (45% (v/v) ethanol) or water together with a high-fat meal, respectively. Compared with baseline, serum uric acid was significantly increased in TFL group (0.5-hour: P = 0.012; 1-hour: P = 0.001; 2-hour: P = 0.008) and it was significantly decreased in WC group (1-hour: P = 0.001; 2-hour: P = 0.001; 4-hour: P < 0.001), while uric acid was non-significantly increased in the TCL group. High-sensitive C-reactive protein (hs-CRP) was significantly increased in the TCL (P = 0.014) and WC (P = 0.008) groups at postprandial 4 hours compared with baseline. There was no significant difference between groups during the postprandial period for these two parameters or other biochemical parameters. In conclusion, both liquors increased postprandial uric acid, and no significant difference was observed for the effects of TFL and TCL on the measured biochemical parameters.

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Journal of Thermal Analysis and Calorimetry
Authors: L. Xu, Y. De-Jun, L. Qiang-Guo, L. Ai-Tao, Y. Li-Juan, J. Qian-Hong and L. Yi

Abstract  

The product from reaction of samarium chloride hexahydrate with salicylic acid and Thioproline, [Sm(C7H5O3)2·(C4H6NO2S)]·2H2O, was synthesized and characterized by IR, elemental analysis, molar conductance, and thermogravimetric analysis. The standard molar enthalpies of solution of [SmCl3·6H2O(s)], [2C7H6O3(s)], [C4H7NO2S(s)] and [Sm(C7H5O3)2·(C4H7NO2S)·H2O(s)] in a mixed solvent of absolute ethyl alcohol, dimethyl sulfoxide(DMSO) and 3 mol L−1 HCl were determined by calorimetry to be Δs H m Φ[SmCl3 δ6H2O (s), 298.15 K]= −46.68±0.15 kJ mol−1 Δs H m Φ[2C7H6O3 (s), 298.15 K]= 25.19±0.02 kJ mol−1, Δs H m Φ[C4H7NO2S (s), 298.15 K]=16.20±0.17 kJ mol−1 and Δs H m Φ[Sm(C7H5O3)2·(C4H6NO2S)]·2H2O (s), 298.15 K]= −81.24±0.67 kJ mol−1. The enthalpy change of the reaction

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$SmCl_3 \cdot 6H_2 O(s) + 2C_7 H_6 O_3 (s) + C_4 H_7 NO_2 S(s) = Sm(C_7 H_5 O_3 )_2 \cdot (C_4 H_6 NO_2 S) \cdot 2H_2 O(s) + 3HCl(g) + 4H_2 O(1)$$ \end{document}
((1)) was determined to be Δs H m Φ =123.45±0.71 kJ mol−1. From date in the literature, through Hess’ law, the standard molar enthalpy of formation of Sm(C7H5O3)2(C4H6NO2S)δ2H2O(s) was estimated to be Δs H m Φ[Sm(C7H5O3)2·(C4H6NO2S)]·2H2O(s), 298.15 K]= −2912.03±3.10 kJ mol−1.

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Journal of Thermal Analysis and Calorimetry
Authors: L. Yang, Li Sun, Fen Xu, J. Zhang, J. Zhao, Z. Zhao, C. Song, R. Wu and Riko Ozao

Abstract  

The microcalorimetric method has been used to study the effects of cefpiramide and ceftizoxime sodium on the E. coli growth. The results revealed that these two cephalosporins may alter the metabolic way of the E. coli. Moreover, the lethal doses of cefpiramide and ceftizoxime sodium are 2.000 and 0.2000 μg mL−1, respectively. Combining with the relationships between growth rate constant (k), the maximum power output (P m), the time corresponding to the maximum power output (t m) and cephalosporins concentration (C), one can draw the conclusion that the ceftizoxime sodium has a stronger inhibition effects on the growth of E. coli than that of cefpiramide and they both have the possibility to induce the drug fever.

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Abstract  

The complex from reaction of neodymium chloride six-hydrate with salicylic acid and 8-hydroxyquinoline, Nd(C7H5O3)2·(C9H6NO), was synthesized and characterized by IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [NdCl3·6H2O(s)], [2C7H6O3(s)], [C9H7NO(s)] and [Nd(C7H5O3)2·(C9H6NO)(s)] in a mixed solvent of anhydrous ethanol, dimethyl formamide (DMF) and perchloric acid were determined by calorimetry at 298.15 K. Based on Hess’ law, a new chemical cycle was designed, and the enthalpy change of the reaction

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$NdCl_3 \cdot 6H_2 O(s) + 2C_7 H_6 O_3 (s) + C_9 H_7 NO(s) = Nd(C_7 H_5 O_3 )_2 \cdot (C_9 H_6 NO)(s) + 3HCl(g) + 6H_2 O(l)$$ \end{document}
((1)) was determined to be Δr H m Θ=117.89±0.37 kJ mol−1. From data in the literature, through Hess’ law, the standard molar enthalpy of formation of Nd(C7H5O3)2·(C9H7NO)(s) was estimated to be Δf H m Θ[Nd(C7H5O3)2·(C9H6NO)(s), 298.15 K]=−2031.80±8.6 kJ mol−1.

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Abstract  

The constant-volume combustion energies of the lead salts of 2-hydroxy-3,5-dinitropyridine (2HDNPPb) and 4-hydroxy-3,5-dinitropyridine (4HDNPPb), ΔU c (2HDNPPb(s) and 4HDNPP(s)), were determined as –4441.922.43 and –4515.741.92 kJ mol–1 , respectively, at 298.15 K. Their standard enthalpies of combustion, Δc m H θ(2HDNPPb(s) and 4HDNPPb(s), 298.15 K), and standard enthalpies of formation, Δr m H θ(2HDNPPb(s) and 4HDNPPb(s), 298.15 K) were as –4425.812.43, –4499.631.92 kJ mol–1 and –870.432.76, –796.652.32 kJ mol–1 , respectively. As two combustion catalysts, 2HDNPPb and 4HDNPPb can enhance the burning rate and reduce the pressure exponent of RDX–CMDB propellant.

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Journal of Thermal Analysis and Calorimetry
Authors: Chun-Hong Jiang, Li-Fang Song, Jian Zhang, Li-Xian Sun, Fen Xu, Fen Li, Qing-Zhu Jiao, Zhen-Gang Sun, Yong-Heng Xing, Yong Du, Ju-Lan Zeng and Zhong Cao

Abstract

A novel metal organic framework [Co (BTC)1/3 (DMF) (HCOO)]n (CoMOF, BTC = 1,3,5-benzene tricarboxylate, DMF = N,N-dimethylformamide) has been synthesized solvothermally and characterized by single crystal X-ray diffraction, X-ray powder diffraction, and FT-IR spectra. The molar heat capacity of the compound was measured by modulated differential scanning calorimetry (MDSC) over the temperature range from 198 to 418 K for the first time. The thermodynamic parameters such as entropy and enthalpy versus 298.15 K based on the above molar heat capacity were calculated. Moreover, a four-step sequential thermal decomposition mechanism for the CoMOF was investigated through the thermogravimetry and mass spectrometer analysis (TG-DTG-MS) from 300 to 800 K. The apparent activation energy of the first decomposition step of the compound was calculated by the Kissinger method using experimental data of TG analysis.

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Journal of Thermal Analysis and Calorimetry
Authors: Li-Fang Song, Chun-Hong Jiang, Cheng-Li Jiao, Jian Zhang, Li-Xian Sun, Fen Xu, Qing-Zhu Jiao, Yong-Heng Xing, Yong Du, Zhong Cao and Feng-Lei Huang

Abstract

A metal-organic framework [Mn(4,4′-bipy)(1,3-BDC)]n (MnMOF, 1,3-BDC = 1,3-benzene dicarboxylate, 4,4′-bipy = 4,4′-bipyridine) has been synthesized hydrothermally and characterized by single crystal XRD and FT-IR spectrum. The low-temperature molar heat capacities of MnMOF were measured by temperature-modulated differential scanning calorimetry for the first time. The thermodynamic parameters such as entropy and enthalpy relative to reference temperature 298.15 K were derived based on the above molar heat capacity data. Moreover, the thermal stability and the decomposition mechanism of MnMOF were investigated by thermogravimetry analysis-mass spectrometer. A two-stage mass loss was observed in air flow. MS curves indicated that the gas products of oxidative degradation were H2O, CO2, NO, and NO2.

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To explore the physiological characteristics of the pepc gene in transgenic wheat (Triticum aestivum) plants, PEPC activities in various organs of T3 plants were analyzed at Feekes 6.0, Feekes 10.3 and Feekes 11.1, and compared to control, untransformed wheat cultivar Zhoumai 19. Net photosynthetic rates (P n) in leaves were also measured at the same stages. At Feekes 11.1, both transgenic and control plants were treated with DCDP. Yield traits were surveyed after harvest. The results indicated that P n and PEPC activity in the flag leaf of transgenic wheat were significantly higher than those of the control at different stages. At Feekes 10.3, P n reached the highest value at 28.2 μmol m−2 s−1 and PEPC activity reached the highest value at 104.6 μmol h−1 mg−1. Both factors significantly increased by 21% compared to the control at Feekes 11.1. PEPC activity in the flag leaf of transgenic plants was significantly higher than that of non-leaf organs. P n of transgenic plants was greatly reduced after DCDP treatment. In the flag leaf of transgenic wheat, P n was significantly correlated to PEPC activities at 0.01 probability level with a correlation coefficient of 0.8957**. The yield traits of transgenic line 1-27-3, such as 1000-grain weight, single spike weight and harvest index were higher than those of the control. Additionally, the spike weight of 1-27-3 showed an increase of approximately 9.5% compared to the control. These results indicated that the expression of maize (Zea mays) pepc gene was different across various organs of transgenic wheat and across every growth stage. Therefore, we conclude that introducing maize pepc gene into wheat plants can increase their P n and improve production.

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Exploring antibiotic resistant mechanism by microcalorimetry II

Determination of thermokinetic parameters of imipenem hydrolysis with metallo-β-lactamase ImiS

Journal of Thermal Analysis and Calorimetry
Authors: Xia Yang, Lei Feng, Kang-Zhen Xu, Hui-Zhou Gao, Chao Jia, Cheng-Cheng Liu, Jian-Min Xiao, Le Zhai, Li-Sheng Zhou and Ke-Wu Yang

Abstract

In an effort to understand the reaction of antibiotic hydrolysis with B2 metallo-β-lactamases (MβLs), the thermodynamic parameters of imipenem hydrolysis catalyzed by metallo-β-lactamase ImiS from Aeromonas veronii bv. sobria were determined by microcalorimetric method. The values of activation free energy are 86.400 ± 0.043, 87.543 ± 0.034, 88.772 ± 0.024, and 89.845 ± 0.035 kJ mol−1 at 293.15, 298.15, 303.15, and 308.15 K, respectively, activation enthalpy is 18.586 ± 0.009 kJ mol−1, activation entropy is −231.34 ± 0.12 J mol−1 K−1, apparent activation energy E is 21.084 kJ mol−1, and the reaction order is 1.5. The thermodynamic parameters reveal that the imipenem hydrolysis catalyzed by metallo-β-lactammase ImiS is an exothermic and spontaneous reaction.

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