Authors:L. Yang, Li Sun, Fen Xu, J. Zhang, J. Zhao, Z. Zhao, C. Song, R. Wu, and Riko Ozao
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 (Pm), the time corresponding to the maximum power output (tm) 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.
Authors:Z. Xiao, D. Liu, C. Wang, Z. Cao, X. Zhan, Z. Yin, Q. Chen, H. Liu, F. Xu, and L. Sun
The effect of mechanical alloying on Zn-Sb alloy system is investigated with X-ray diffraction (XRD), laser grain size analysis
and differential scanning calorimetry (DSC) respectively. The results of laser particle size analysis shows that the particle
size decreases with increasing of the grinding time between 0 and 24 h. XRD and DSC results indicate that longer the grinding
time of Zn-Sb is, the more content of Zn4Sb3 become in the product in this process.
Authors:Z. Zhang, T. Cui, J. Zhang, H. Xiong, G. Li, L. Sun, F. Xu, Z. Cao, F. Li, and J. Zhao
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, CP,m (J K−1 mol−1) = 204.75 + 81.421X − 23.828 X2 + 12.044X3 + 2.5442X4 [X = (T − 132.5)/52.5] for the solid phase (80–185 K), CP,m (J K−1 mol−1) = 368.99 + 2.4199X + 1.0027X2 + 0.43395X3 [X = (T − 230)/35] for the glass state (195 − 265 K), and CP,m (J K−1 mol−1) = 415.01 + 21.992X − 0.24656X2 + 0.57770X3 [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 ΔHg = 2.853 kJ mol−1 and ΔSg = 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 ΔHm = 20.67 kJ mol−1 and ΔSm = 73.34 J K−1 mol−1.
Authors:P. Yu, Z. Tan, S. Meng, S. Lu, X. Lan, L. Sun, F. Xu, T. Zhang, and S. Hu
Isoproturon [N'-(p-cumenyl)-N,N-dimethylurea] was synthesized, and the low-temperature heat capacities were measured with a small sample precise
automatic adiabatic calorimeter over the temperature range from 78 to 342 K. No thermal anomaly or phase transition was observed
in this temperature range. The melting and thermal decomposition behavior of isoproturon was investigated by thermogravimetric
analysis (TG) and differential scanning calorimetry (DSC). The melting point and decomposition temperature of isoproturon
were determined to be 152.4 and 239.0C. The molar melting enthalpy, and entropy of isoproturon, ΔHm and ΔSm, were determined to be 21.33 and 50.13 J K-1 mol-1, respectively. The fundamental thermodynamic functions of isoproturon relative to standard reference temperature, 298.15
K, were derived from the heat capacity data.
Authors:W.-C. Xie, X.-H. Gu, Z.-C. Tan, J. Tang, G.-Y. Wang, C.-R. Luo, and L.-X. Sun
To develop thermal stable flavor, two glycosidic bound flavor precursors, geranyl-tetraacetyl-β-D-glucopyranoside (GLY-A) and geranyl-β-D-glucopyranoside (GLY-B) were synthesized by the modified Koenigs–Knorr reaction. The thermal decomposition process and pyrolysis products of the two glycosides were extensively investigated by thermogravimetry (TG), differential scanning calorimeter (DSC) and on-line pyrolysis-gas chromatography mass spectroscopy (Py-GC-MS). TG showed the Tp of GLY-A and GLY-B were 254.6 and 275.7°C. The Tpeak of GLY-A and GLY-B measured by DSC were 254.8 and 262.1°C respectively.
Py-GC-MS was used for the simply qualitative analysis of the pyrolysis products at 300 and 400°C. The results indicated that: 1) A large amount of geraniol and few by-products were produced at 300°C, the by-products were significantly increased at 400°C; 2) The characteristic pyrolysis product was geraniol; 3) The primary decomposition reaction was the cleavage of O-glycosidic bound of the two glycosides flavor precursors. The study on the thermal behavior and pyrolysis products of the two glycosides showed that this kind of flavor precursors could be used for providing the foodstuff with specific flavor during heating process.
Authors:Y.G. Shi, Y. Lian, H.W. Shi, S.G. Wang, H. Fan, D.Z. Sun, and R.L. Jing
Senescence in a wheat (Triticum aestivum L.) leaf is a programmed degeneration process leading to death. During this process, green leaf area duration (GLAD) and green leaf number of main stem (GLNMS) are gradually reduced. In this study, the two traits of Hanxuan10/Lumai14 DH population at different development stages after anthesis were evaluated under rainfed and irrigated conditions, and QTLs were detected. GLAD and GLNMS of two parents and DH population under rainfed condition were less than those under irrigated condition, and close correlations (P < 0 05) were found between GLAD and GLNMS after 25 DAA under both water conditions. GLAD and GLNMS were co-controlled by major and minor genes. QTLs for GLAD were stably expressed at different development stages after anthesis under both water conditions, such as QGlad22-1B-1, QGlad25-1B-1, QGlad28-1B-2 detected under irrigated condition and QGlad25-1B-3, QGlad28-1B-4 mapped under rainfed condition were located at a 20.7 cM marker interval of Xgwm273-EST122 on 1B chromosome. But QTLs for GLNMS were inducibly and specifically expressed at specific developmental stages after anthesis under both water conditions. The findings provide dynamic genetic information related to wheat senescence.
Authors:X.-C. Lv, Z.-C. Tan, Z.-A. Li, Y.-S. Li, J. Xing, Q. Shi, and L.-X. Sun
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 Cp,m
of the compound were measured over the temperature range from 80 to 378 K
with a small sample automated adiabatic calorimeter. Thermodynamic functions
[HT–H298.15] and [ST–S298.15] 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.
Authors:F. Xu, L. Sun, J. Zhang, Y. Qi, L. Yang, H. Ru, C. Wang, X. Meng, X. Lan, Q. Jiao, and F. Huang
Heat capacities of the carbon nanotubes (CNTs) with different sizes have been measured by modulated temperature differential
scanning calorimetry (MDSC) and reported for the first time. The results indicated the values of Cp increased with shortening length of CNTs when the diameters of CNTs were between 60 and 100 nm. However, the values of Cp of CNTs were not affected by their diameter when the lengths of CNTs were 1–2 um, or not affected by the length of CNTs when
their diameters were below 10 nm. The thermal stabilities of the CNTs have been studied by TG-DTG-DSC. The results of TG-DTG
showed that thermal stabilities of CNTs were enhanced with their diameters increase. With lengths increase, the thermal stabilities
of CNTs increased when their diameters were between 60 and 100 nm, but there is a slight decrease when their diameters were
less than 60 nm. The further DSC analyses showed both released heat and Tonset increased with the increase of CNTs diameters, which confirms the consistency of the results from both TG-DTG and DSC on
CNTs thermal stability.
Authors:F. Xu, L. Sun, P. Chen, Y. Qi, J. Zhang, J. Zhao, Y. Liu, L. Zhang, Zhong Cao, D. Yang, J. Zeng, and Y. Du
The heat capacities of LiNH2 and Li2MgN2H2 were measured by a modulated differential scanning calorimetry (MDSC) over the temperature range from 223 to 473 K for the
first time. The value of heat capacity of LiNH2 is bigger than that of Li2MgN2H2 from 223 to 473 K. The thermodynamic parameters such as enthalpy (H–H298.15) and entropy (S–S298.15) versus 298.15 K were calculated based on the above heat capacities. The thermal stabilities of them were investigated by
thermogravimetric analysis (TG) at a heating rate of 10 K min−1 with Ar gas flow rate of 30 mL min−1 from room temperature to 1,080 K. TG curves showed that the thermal decomposition of them occurred in two stages. The order
of thermal stability of them is: Li2MgN2H2 > LiNH2. The results indicate that addition of Mg increases the thermal stability of Li–N–H system and decrease the value of heat
capacities of Li–N–H system.
Authors:K.J. Deng, J.P. Zhou, X.H. Wu, G. Sun, T. Wang, A.T. Tang, X.L. Zheng, and Y. Zhang
It is well demonstrated that wheat-rye 1BL/1RS translocated chromosome leads to some valuable novel traits such as disease resistance, high yield and functional stay-green after anthesis. To understand the physiological mechanism of 1BL/1RS translocation responsible for osmotic stress, two wheat cultivars, CN12 and CN17, carrying the translocated chromosome and MY11 without the translocated chromosome were employed in the study. During 5-day osmotic stress, fresh weight inhibition, chlorophyll content, soluble protein content, MDA concentration, antioxidant enzymes activity and free polyamines content were examined. CN12 and CN17, especially cultivar CN17, registered greater biomass and minor oxidative damage compared with their wheat parent. Meanwhile, the concentration of Spd and Spm in CN17 was significantly higher than the others. In addition, we found a positive correlation of fresh weight inhibition (FWI) and Put concentration, and a negative one with the parameters (Spd + Spm): Put ratio, indicating the importance of higher polyamine (Spd and Spm) accumulation on the adaptation to osmotic stress. Therefore, we proposed that the accumulation of higher polyamines (Spd and Spm) should play an important role on the adaptation of 1BL/1RS translocation lines to osmotic stress and might be important factors for the origin of novel traits introduced by 1BL/1RS.