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Thermodynamic investigation of room temperature ionic liquid

Heat capacity and thermodynamic functions of BMIBF4

Journal of Thermal Analysis and Calorimetry
Authors: Z. Zhang, Z. Tan, Y. Li, and L. Sun

Abstract  

The molar heat capacities of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) 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)= 195.55+47.230 X–3.1533 X 2+4.0733 X 3+3.9126 X 4 [X=(T–125.5)/45.5] for the solid phase (80~171 K), and C P,m (J K–1 mol–1)= 378.62+43.929 X+16.456 X 2–4.6684 X 3–5.5876 X 4 [X=(T–285.5)/104.5] for the liquid phase (181~390 K), respectively. According to the polynomial equations and thermodynamic relationship, the values of thermodynamic function of the BMIBF4 relative to 298.15 K were calculated in temperature range from 80 to 390 K with an interval of 5 K. The glass translation of BMIBF4 was observed at 176.24 K. Using oxygen-bomb combustion calorimeter, the molar enthalpy of combustion of BMIBF4 was determined to be Δc H m o= – 5335±17 kJ mol–1. The standard molar enthalpy of formation of BMIBF4 was evaluated to be Δf H m o= –1221.8±4.0 kJ mol–1 at T=298.150±0.001 K.

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Abstract  

AP/HTPB based composite propellants with additives such as ammonium oxalate (AO), mixture of ammonium oxalate and strontium carbonate (SC) was investigated by burning rate, TG-DTG and FTIR experiments. The results show that the burning rates of these propellants are decreased significantly. TG-DTG experiments indicate that decomposition temperatures of AP with these additives are increased. Furthermore, the activation energy of the decomposition reaction of AP is also increased in the presence of AO or AO/SC. These results show that AO or AO/SC restrains the decomposition of AP. The burning rates of these propellants are decreased. The burning rate temperature sensitivity of AP/HTPB based propellants is reduced significantly by the addition of AO or AO/SC. But the effect of AO is less than that of AO/SC. AO/SC is better effect to reduce temperature sensitivity and at the same time, to reduce pressure exponent. The reduced heat release at the burning surface of AP/HTPB/AO is responsible for the reduced temperature sensitivity. Synergetic action is probably produced between AO and SC within AP/HTPB based propellants in the pressure range tested. This synergetic effect causes the heat release to reduce and the burning surface temperature to increase. Moreover, it makes the net exothermal reaction of condensed phase become little dependent on T 0. Thus, the burning rate temperature sensitivity is reduced.

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Abstract  

The enthalpies of dilution of aqueous solutions for pyridine and methylpyridine isomers have been determined with a 2277-Thermal Activity Monitor at 298.15 K. The results have been treated using the excess function concept and homotactic interaction coefficients have been obtained. The homotactic enthalpic pairwise interaction coefficients are discussed qualitatively in terms of substitution effects of methyl group introduced into the pyridine ring.

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Berberine, a primary pharmacological active constitute of Coptidis Rhizoma, could inhibit neuronal apoptosis in cerebral ischemia. Here, we aimed to investigate whether and how HIF-1 is implicated in the anti-apoptosis effect of berberine on neurons under hypoxia/ischemia. Viability of PC12 cells treated with berberine prior to or following CoCl2-induced hypoxia was evaluated. Annexin V-PI staining was employed to analyse cell apoptosis ratio. HIF-1α and apoptosis-associated molecules were detected via Western blotting. TUNEL and immunohistochemistry were used to demonstrate apoptosis, HIF-1α and p53 levels in cerebral tissue of middle cerebral artery occlusion (MCAO) rats. Berberine pretreatment promoted PC12 cells survival and inhibited apoptosis under hypoxia condition. At the same time, it decreased cell viability and enhancement of apoptosis were observed with berberine treatment under hypoxia. Decreased HIF-1α, caspase 9, caspase 3 and increased Bcl-2/Bax ratio were responsible for the anti-apoptosis of berberine pretreatment. However, pro-apoptosis by berberine under hypoxia was indicated with opposing regulation of those molecules. Significant reduction of apoptosis, HIF-1α and p53 were found in cerebral tissue of MCAO rats treated with berberine. The present study suggests that berberine regulates neuronal apoptosis in cerebral ischemia, which might be dependent on the degree of cell injury. HIF-1 and the followed apoptotic pathway are involved in those effects of berberine.

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Thinopyrum ponticum is particularly a valuable source of genes for wheat improvement. A novel wheat-Th. ponticum addition line, 1–27, was identified using cytology, SSR, ESTSSR, EST-STS and PCR-based landmark unique gene (PLUG) markers in this study. Cytological studies showed that 1–27 contained 44 chromosomes and formed 22 bivalents at meiotic metaphase I. Genomic in situ hybridization (GISH) analysis indicated that two chromosomes from Th. ponticum had been introduced into 1–27 and that these two chromosomes could form a bivalent in wheat background. Such results demonstrated that 1–27 was a disomic addition line with 42 wheat chromosomes and a pair of Th. ponticum chromosomes. One SSR marker (BARC235), one EST-STS marker (MAG3284) and 8 PLUG markers (TNAC1210, TNAC1787, TNAC1803, TNAC1805, TNAC1806, TNAC1821, TNAC1867 and TNAC1957), which were all from wheat chromosome group 7, produced the specific band in Th. ponticum and 1–27, indicating that the introduced Th. ponticum chromosomes belonging to the group 7 of wheat. Sequence analysis on specific bands from Th. ponticum and 1–27 amplified using the PLUG marker TNAC1867 further confirmed this result. The 1–27 addition line was also observed to be high resistant to powdery mildew though it is not clear if the resistance of 1–27 inherited from Th. ponticum. This study provided some useful information for effective exploitation of the source of genetic variability in wheat breeding.

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Cereal Research Communications
Authors: X. Zhang, Y. Chen, Y. Wei, W. Lu, H. Liao, Y. Liu, X. Yang, X. Li, L. Yang, L. Li, and R. Li

Partial abortion of gametes possessing S-5 j in S-5 i / S-5 j genotype at locus S-5 is responsible for hybrid sterility between indica and japonica subspecies in rice ( Oryza sativa L.), while a single wide compatibility (WC) allele S-5 n can restore normal hybrid fertility between the two groups. In this study, Pei’ai 64S, one of the most popular WC line widely used for subspecific hybrid rice breeding program in South China was studied for location of its S-5 locus. Twenty SSR (Simple Sequence Repeat) markers derived from Cornell SSR linkage map and 9 developed using sequences from GenBank database were employed to perform bulked segregant analysis of the mapping population derived from a three-way cross (Pei’ai 64S/T8//Akihikari) to tag fine location of the hybrid sterility locus, S-5 . This S-5 locus was mapped on chromosome 6 approximately 0.2 cM from GXR6 and RM276 SSR markers. This tight linkage of the markers and the S-5 locus would be very useful for efficient marker-assisted selection for WC varieties and for map-based cloning of the gene.

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Leaf senescence is a notably important trait that limits the yield and biomass accumulation of agronomic crops. Therefore, determining the chromosomal position of the expression sequence tags (ESTs) that are associated with leaf senescence is notably interesting in the manipulation of leaf senescence for crop improvement. A total of 32 ESTs that were previously identified during the delaying leaf senescence stage in the stay-green wheat cultivar CN17 were mapped to 42 chromosomes, a chloroplast, a mitochondrion, and a ribosome using in silico mapping. Then, we developed 19 pairs of primers based on these sequences and used them to determine the polymorphisms between the stay-green cultivars (CN12, CN17, and CN18) and the control cultivar MY11. Among the 19 pairs of primers, 5 pairs produced polymorphisms between the stay-green cultivar and the non-stay-green control. Further studies of Chinese Spring nullisomic-tetrasomics show that JK738991 is mapped to 3B, JK738983 is mapped to 5D, and JK738989 is mapped to 2A, 4A, and 3D. The other two ESTs, JK738994 and JK739003, were not assigned to a chromosome using the Chinese Spring nullisomic-tetrasomics, which indicates that these ESTs may be derived from rye DNA in the wide cross. In particular, the ESTs that produce polymorphisms are notably useful in identifying the stay-green cultivar using molecular marker-assisted selection. The results also suggest that the in silico mapping data, even from a comparison genomic analysis based on the homogeneous comparison, are useful at some points, but the data were not always reliable, which requires further investigation using experimental methods.

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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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Abiotic stresses like salinity and abnormally cold environments cause significant yield losses in many crops including wheat. Therefore, concerted efforts are being made by breeders to develop new varieties with salt and cold tolerance to ensure stable yields over varied environments. This study was undertaken to screen six hundred and seventy-seven accessions of international wheat genetic resources to identify lines with high level of tolerance to salinity and cold environments. Based on the results of two years study in different agroecological locations, 51 accessions were classified as salt tolerant and 115 accessions were classified as cold tolerant. Of these, 35 accessions had good agronomic characteristics. Also, there were 39 genotypes with combined tolerance to cold as well as salinity. Thus, there were good lines which can be used directly or as parents for breeding wheat varieties for wide adaptation and high yield. Further analysis of the data showed that early genotypes had good cold tolerance but a poor salt tolerance. It was also observed that small number of both test spikelet and spikelet, short spike length and good seed-plump were positively associated with cold tolerance. Therefore, maturity and spike traits should be taken into considered when selecting wheat lines for wide adaptation breeding.

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Optimization of extraction ratio (ER) of tree peony seed protein (TPSP) was investigated using response surface methodology (RSM). The second-degree equation for ER of TPSP had high coeffi cient (0.9625) of determination. The probability (P) value of regression model signifi cance was less than 0.001 by analysis of central composite rotatable design. Relationships of ER to pH, liquid/solid ratio, squares of all factors, and cross-product factors (x2x3, x2x4, x3x4) were signifi cant (P<0.05). Whereas, extraction time, temperature, and cross-product terms (x1x2, x1x3, x1x4) were not signifi cant factors (P>0.05). Optimum extraction conditions were 3.42 h, pH 9.50, 50.80 ºC, and 9.54 ml g–1 of liquid/solid ratio with the maximum ER (43.60%) . SDS-PAGE indicated TPSP had mainly four proteins (180, 100, 60, and 35 kDa) with four subunits of 60, 48, 38, and 23 kDa. TPSP had a good amino acid composition with abundant essential amino acids (39.76%) determined by amino acid analysis.

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