Use of liquid crystal to study the interactions of alkyl polyglycosides with gelatin and bovine serum albumin

In this study, liquid crystal (LC) was used to study the interactions of alkyl polyglycosides (APG) with gelatin and bovine serum albumin (BSA) at the LC-aqueous interface. The LC easily undergo an orientational transition from a homeotropic to a planar state after proteins were in contact to the LCaqueous interface decorated with APG, thus inducing an optical change from dark to bright. The optical image analysis reveals that the rearrangement rate of APG monolayer is tightly dependent on the concentration and chemical structure of the protein of interest. For example, the rearrangement rate of APG monolayer increases with an increasing gelatin concentration. We also find that the chemical structure of the proteins has a significant impact on the difference in the growth behavior of bright domains in LC.     

Comparison of aroma-active volatiles and their sensory characteristics of mangosteen wines prepared by Saccharomyces cerevisiae with GC-olfactometry and principal component analysis

Mangosteen fruit is fermented with five different strains (i.e. GRE (Y1), Lalvin RC212 (Y2), Lalvin D254 (Y3), CGMCC2.23 (Y4) and CGMCC2.4 (Y5)) of the yeast Saccharomyces cerevisiae to make mangosteen wines. A total of 36 volatile compounds of the mangosteen wines were identified by gas chromatography-mass spectrometry and gas chromatography-pulsed flame photometric detection. A total of 35 odour-active compounds were identified by gas chromatography-olfactometry analysis and by the detection frequency (DF) method. The compounds with high DF values included ethyl octanoate, ethyl hexanoate and 3-methyl-2-butene-1-thiol. Principal component analysis was used to characterise the differences of the flavour profiles of those mangosteen wines. The result demonstrated that the samples could be divided into three groups that were associated closely with aroma-active compounds.     

Novel reversible thermoresponsive nanogel based on poly(ionic liquid)s prepared via RAFT crosslinking copolymerization

In this study, a facile strategy for the preparation of thermo‐ and pH‐responsive nanogels through reversible addition–fragmentation transfer (RAFT) crosslinking copolymerization of ionic liquid‐based monomers is demonstrated. The use of chain transfer agents (CTAs) containing carboxyl group in the RAFT polymerizations is the key to producing highly thermoresponsive nanogels. Experimental results demonstrate that the critical gelation temperature of the as‐prepared nanogels can be tuned by adjusting the feed ratio of monomer and CTA. Variable temperature Fourier transform infrared measurements and control experiments indicate that hydrogen‐bonding interactions between the carboxyl groups of CTAs are responsible for the thermoresponsive behaviors of poly(ionic liquid) (PIL)‐based nanogels. Furthermore, PIL‐based nanogels are also found to be pH‐sensitive, and can be further decorated by poly(N‐isopropylacrylamide) (PNIPAAm) via surface grafting polymerization. PNIPAAm‐grafted nanogel aqueous solutions can be reversibly transformed into macrogels upon a change in temperature. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 169–178     

Electrophoretic separation of multiple chiral center analyte with a three cyclodextrins mixture

A capillary electrokinetic chromatography method (CEKC) was developed for complete stereoisomeric separation of a neutral, hydrophobic, multiple chiral center dihydropyridone analogue, a drug candidate proposed in type 2 diabetes treatment. A background electrolyte comprising three cyclodextrins was found to successfully separate the eight isomers. First an anionic cyclodextrin, the SBE-β-CD, was selected to allow the chiral separation of our neutral compound and partial resolutions of the eight isomers were obtained. Then, the effects of different parameters such as the nature and concentration of the other cyclodextrins added and pH of the buffer were examined. Finally, a triple CD-system consisted of 15 mM SBE-β-CD plus 15 mM γ-CD and 40 mM HP-γ-CD in a 50 mM borate background electrolyte at pH 10, was found to successfully separate the eight isomers. Last, the selectivity and limits of detection and quantification were evaluated for this optimized method.     

基于信息分配和扩散理论的东北地区干旱脆弱性特征分析

基于信息分配和扩散理论, 结合标准化降水指数和东北三省(黑龙江、吉林、辽宁)旱灾灾损指数, 综合考虑了气象因子与社会因子, 分析了我国东北三省1971–2012年的干旱脆弱性特征, 并进一步计算了我国东北三省的干旱风险. 使用信息分配方法估计干旱强度概率分布, 采用二维正态信息扩散方法构造了干旱强度与旱灾灾损的脆弱性关系, 将干旱强度的概率分布与脆弱性折线相乘求和(离散分布)或积分(连续分布)即可得到多年平均风险. 研究表明, 针对灾损的小样本事件引入信息分配和扩散方法对小样本数据进行分析, 获取的干旱强度概率分布比简单直方图法所得更加平滑, 而以事件为因、灾损为果得到干旱强度-旱灾灾损的脆弱性关系, 物理意义明确, 所得脆弱性关系折线也比较符合实际情况, 并且不同样本长度所得结果相近, 对样本长度不敏感, 较好地克服了小样本分析的不稳定性. 关键词： 信息分配和扩散理论 标准化降水指数 脆弱性 风险     

An HPLC method for the determination of a novel anti‐hypertension agent 6,7‐dimethoxy‐3‐[4‐(4‐fluorobenzyloxy)‐3‐methoxyphenylmethyl]quinazolin‐4(3H)‐one in rat plasma: application to pharmacokinetic study

6,7‐Dimethoxy‐3‐[4‐(4‐fluorobenzyloxy)‐3‐methoxyphenylmethyl] quinazolin‐4(3H)‐one (DFMQ‐19), a novel analog of 3‐benzylquinazolin‐4(3H)‐ones, may be considered as a drug candidate for the treatment of hypertension. The aim of this study was to develop and validate a reverse‐phase high‐performance liquid chromatography to determine the DFMQ‐19 in plasma and demonstrate its application in pharmacokinetic studies. Separation of DFMQ‐19 and IS (structural analog of DFMQ‐19) was performed using a Shim‐Pack VP‐ODS column and a mixture of acetonitrile and water as mobile phase. The HPLC method was validated according to the International Conference on Harmonization guidelines. The limit of detection and lower limit of quantitation were 0.05 and 0.1 μg/mL, respectively. The recovery rate of DFMQ‐19 from blood samples was >81% of the spiked amount. The RSD of the intra‐ and inter‐day precisions was within 7.5%, and RE of accuracy was between ?14.4 and 4.5%. This method was successfully applied to the pharmacokinetic study after administration of DFMQ‐19. The pharmacokinetic parameters, such as half‐life, mean residence time and maximum concentration were determined. Based on these pharmacokinetic parameters, the oral bioavailability of DFMQ‐19 was calculated to be 13.42% in rat. Copyright © 2016 John Wiley & Sons, Ltd.     

Preface: Special topic on Metal-organic frameworks (MOFs)

正Metal-organic frameworks,MOFs,are coordination networks with organic ligands and voids.At the fundamental level,MOFs epitomize the beauty of chemical structures and the power of combining organic and inorganic chemistry,two disciplines that are often regarded as disparate.MOFs have recently emerged as an extensive class of crystalline materials with ultrahigh porosity and internal surface     

Two supersymmetric hierarchies related to the super-HS spectral problem

In this paper, we construct Lax pairs and super-bihamiltonian structures of two supersymmetric integrable hierarchies related to a given super-HS spectral problem.     

Imino‐indolate half‐titanocene chlorides: Synthesis and their ethylene (co‐)polymerization

A series of imino‐indolate half‐titanocene chlorides, Cp′Ti(L)Cl₂ ( C1 – C7 : Cp′ = C₅H₅, MeC₅H₄, C₅Me₅, L = imino‐indolate ligand), were synthesized by the reaction of Cp′TiCl₃ with sodium imino‐indolates. All complexes were characterized by elemental analysis, ¹H and ¹³C NMR spectroscopy. Moreover, the molecular structures of two representative complexes C4 and C6 were confirmed by single crystal X‐ray diffraction analysis. On activation with methylaluminoxane (MAO), these complexes showed good catalytic activities for ethylene polymerization (up to 7.68 × 10⁶ g/mol(Ti)·h) and ethylene/1‐hexene copolymerization (up to 8.32 × 10⁶ g/mol(Ti)·h), producing polyolefins with high molecular weights (for polyethylene up to 1808 kg/mol, and for poly(ethylen‐co‐1‐hexene) up to 3290 kg/mol). Half‐titanocenes containing ligands with alkyl substituents showed higher catalytic activities, whereas the half‐titanocenes bearing methyl substituents on the cyclopentadienyl groups showed lower productivities, but produced polymers with higher molecular weights. Moreover, the copolymerization of ethylene and methyl 10‐undecenoate was demonstrated using the C1 /MAO catalytic system. The functionalized polyolefins obtained contained about 1 mol % of methyl 10‐undecenoate units and were fully characterized by several techniques such as FT‐IR, ¹H NMR, ¹³C NMR, DSC, TGA and GPC analyses. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 357–372, 2009