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Abstract  

The power vs. time curves of the promoter bacteria of a nutrient drug were determined by using a 2277 Thermal Activity Monitor (Sweden). A new experimental model of bacterial growth were established. The growth rate constant, heat output and optimum concentration of specific promoter bacterial of nutrient drug were calculated.

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Thermodynamic investigation of room temperature ionic liquid

The heat capacity and thermodynamic functions of BMIPF6

Journal of Thermal Analysis and Calorimetry
Authors: Z. Zhang, T. Cui, J. Zhang, H. Xiong, G. Li, L. Sun, F. Xu, Z. Cao, F. Li, and J. Zhao

Abstract  

The molar heat capacities of the room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluoroborate (BMIPF6) were measured by an adiabatic calorimeter in temperature range from 80 to 390 K. The dependence of the molar heat capacity on temperature is given as a function of the reduced temperature (X) by polynomial equations, C P,m (J K−1 mol−1) = 204.75 + 81.421X − 23.828 X 2 + 12.044X 3 + 2.5442X 4 [X = (T − 132.5)/52.5] for the solid phase (80–185 K), C P,m (J K−1 mol−1) = 368.99 + 2.4199X + 1.0027X 2 + 0.43395X 3 [X = (T − 230)/35] for the glass state (195 − 265 K), and C P,m (J K−1 mol−1) = 415.01 + 21.992X − 0.24656X 2 + 0.57770X 3 [X = (T − 337.5)/52.5] for the liquid phase (285–390 K), respectively. According to the polynomial equations and thermodynamic relationship, the values of thermodynamic function of the BMIPF6 relative to 298.15 K were calculated in temperature range from 80 to 390 K with an interval of 5 K. The glass transition of BMIPF6 was measured to be 190.41 K, the enthalpy and entropy of the glass transition were determined to be ΔH g = 2.853 kJ mol−1 and ΔS g = 14.98 J K−1 mol−1, respectively. The results showed that the milting point of the BMIPF6 is 281.83 K, the enthalpy and entropy of phase transition were calculated to be ΔH m = 20.67 kJ mol−1 and ΔS m = 73.34 J K−1 mol−1.

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The forward and reverse cDNA subtractive libraries before and after the toxic effect of α-amanitin were constructed by suppression subtractive hybridization and randomly selected clones from each subtractive library were screened by PCR and dot blot hybridization. A total of 85 genes with altered expression were finally identified, with 41 genes from the forward library and 44 from the reverse library. Subsequently, the antagonistic effects of candidate traditional Chinese medicines were evaluated based on the genetic transcription levels of the genes with significant altered expression, including Catnβ, Flt3-L, IL-7r and Rpo2-4. The results indicated that Silybum marianum (L.) Gaert and Ganoderma lucidum had significant down-regulated effects on the transcription level of Catnβ that was up-regulated by α-amanitin, and the two herbs also up-regulated the transcription levels of Flt3-L and Rpo2-4. Silybum marianum (L.) had significant up-regulated effects on the IL-7r that was down-regulated by α-amanitin. These preliminary studies suggested that Silybum marianum (L.) and Ganoderma lucidum were effective antagonists against the toxicity of α-amanitin.

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Abstract

In this paper, organic phase change materials (PCM)/Ag nanoparticles composite materials were prepared and characterized for the first time. The effect of Ag nanoparticles on the thermal conductivity of PCM was investigated. 1-tetradecanol (TD) was selected as a PCM. A series of nano-Ag-TD composite materials in aqueous solution were in-situ synthesized and characterized by means of thermal conductivity evaluation method, TG-DSC, IR, XRD and TEM. The results showed that the thermal conductivity of the composite material was enhanced as the loading of Ag nanoparticles increased. The composite materials still had relatively large phase change enthalpy. Their phase change enthalpy could be correlated linearly with the loading of TD, but their phase change temperature was a little bite lower than that of pure TD. The thermal stability of the composite materials was close to that of pure TD. It appeared that there was no strong interaction between the Ag nanoparticles and the TD. Furthermore, the experiment results indicated that the Ag nanoparticles dispersed uniformly in the materials, occurred in the forms of pure metal.

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Journal of Thermal Analysis and Calorimetry
Authors: X.-C. Lv, Z.-C. Tan, Z.-A. Li, Y.-S. Li, J. Xing, Q. Shi, and L.-X. Sun

Abstract  

The (R)-BINOL-menthyl dicarbonates, one of the most important compounds in catalytic asymmetric synthesis, was synthesized by a convenient method. The molar heat capacities C p,m of the compound were measured over the temperature range from 80 to 378 K with a small sample automated adiabatic calorimeter. Thermodynamic functions [H TH 298.15] and [S TS 298.15] were derived in the above temperature range with a temperature interval of 5 K. The thermal stability of the substance was investigated by differential scanning calorimeter (DSC) and a thermogravimetric (TG) technique.

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Abstract  

The molar heat capacities C p,m of 2,2-dimethyl-1,3-propanediol were measured in the temperature range from 78 to 410 K by means of a small sample automated adiabatic calorimeter. A solid-solid and a solid-liquid phase transitions were found at T-314.304 and 402.402 K, respectively, from the experimental C p-T curve. The molar enthalpies and entropies of these transitions were determined to be 14.78 kJ mol−1, 47.01 J K−1 mol for the solid-solid transition and 7.518 kJ mol−1, 18.68 J K−1 mol−1 for the solid-liquid transition, respectively. The dependence of heat capacity on the temperature was fitted to the following polynomial equations with least square method. In the temperature range of 80 to 310 K, C p,m/(J K−1 mol−1)=117.72+58.8022x+3.0964x 2+6.87363x 3−13.922x 4+9.8889x 5+16.195x 6; x=[(T/K)−195]/115. In the temperature range of 325 to 395 K, C p,m/(J K−1 mol−1)=290.74+22.767x−0.6247x 2−0.8716x 3−4.0159x 4−0.2878x 5+1.7244x 6; x=[(T/K)−360]/35. The thermodynamic functions H TH 298.15 and S TS 298.15, were derived from the heat capacity data in the temperature range of 80 to 410 K with an interval of 5 K. The thermostability of the compound was further tested by DSC and TG measurements. The results were in agreement with those obtained by adiabatic calorimetry.

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Abstract  

The effects of Amoxicillin Sodium and Cefuroxime Sodium on the growth of E. coli DH5α were investigated by microcalorimetry. The metabolic power-time curves of E. coli DH5α growth were determined by using a TAM air isothermal microcalorimeter at 37�C. By evaluation of the obtained parameters, such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (P m) and the time of the maximum heat power (t m), one found that the inhibitory activity of Amoxicillin Sodium vs. E. coli DH5α is enhanced with the increasing of the Amoxicillin Sodium concentration, and the Cefuroxime Sodium has a stimulatory effect on the E. coli DH5α growth when the concentration is about 1 μg mL−1. The IC50 for the Amoxicillin Sodium and the Cefuroxime Sodium are 1.6 and 2.0 μg mL−1, respectively, it implicates that the E. coli DH5α is more sensitive to Amoxicillin Sodium than Cefuroxime Sodium.

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Abstract  

The heat capacities of berberine sulphate [(C20H18NO4)2SO43H2O] were measured from 80 to 390 K by means of an automated adiabatic calorimeter. Smoothed heat capacities, H T-H 298.15 and S T-S 298.15 were calculated. The loss of crystalline water started at about 339.30.2 K, and its peak temperature was 365.80.6 K. The peak temperature of decomposition for berberine sulphate was at about 391.40.4 K by DSC curve. TG-DTG analysis of this material was carried out in temperature range from 310 to 970 K. TG and DSC curves show that there is no melting in the whole heating process.

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Journal of Thermal Analysis and Calorimetry
Authors: Y. Y. Di, Z. C. Tan, L. W. Li, S. L. Gao, and L. X. Sun

Abstract

Low-temperature heat capacities of a solid complex Zn(Val)SO4·H2O(s) were measured by a precision automated adiabatic calorimeter over the temperature range between 78 and 373 K. The initial dehydration temperature of the coordination compound was determined to be, T D=327.05 K, by analysis of the heat-capacity curve. The experimental values of molar heat capacities were fitted to a polynomial equation of heat capacities (C p,m) with the reduced temperatures (x), [x=f (T)], by least square method. The polynomial fitted values of the molar heat capacities and fundamental thermodynamic functions of the complex relative to the standard reference temperature 298.15 K were given with the interval of 5 K.

Enthalpies of dissolution of the [ZnSO4·7H2O(s)+Val(s)] (Δsol H m,l 0) and the Zn(Val)SO4·H2O(s) (Δsol H m,2 0) in 100.00 mL of 2 mol dm−3 HCl(aq) at T=298.15 K were determined to be, Δsol H m,l 0=(94.588±0.025) kJ mol−1 and Δsol H m,2 0=–(46.118±0.055) kJ mol−1, by means of a homemade isoperibol solution–reaction calorimeter. The standard molar enthalpy of formation of the compound was determined as: Δf H m 0 (Zn(Val)SO4·H2O(s), 298.15 K)=–(1850.97±1.92) kJ mol−1, from the enthalpies of dissolution and other auxiliary thermodynamic data through a Hess thermochemical cycle. Furthermore, the reliability of the Hess thermochemical cycle was verified by comparing UV/Vis spectra and the refractive indexes of solution A (from dissolution of the [ZnSO4·7H2O(s)+Val(s)] mixture in 2 mol dm−3 hydrochloric acid) and solution A’ (from dissolution of the complex Zn(Val)SO4·H2O(s) in 2 mol dm−3 hydrochloric acid).

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Abstract  

The effects of multi-walled carbon nanotubes (MWNTs) on the phase change enthalpy (ΔH) and the thermal conductivity (κ) of a solid-liquid phase change materials (PCM), palmitic acid (PA), have been investigated. The results showed that both the ΔH and the κ of the composite were lower than that of PA when the loading of MWNTs was small. As the concentration of MWNTs in the composites increased, the ΔH of the composites was slightly improved and then decreased linearly. However, the κ of the composites was monotonously increased from the minimum value. When the loading of MWNTs increased to 5% and no surfactant was added, the κ of the composite was enhanced to be 26% higher than that of PA. The κ of the composite could be enhanced by CTAB instead of SDBS when the loading of MWNTs was small, as SDBS showed no obvious effect on the κ of the composites. Furthermore, the effects of surface modification of MWNTs on the ΔH and the κ of the composites have also been investigated.

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