1H NMR studies of binary and ternary dapsone supramolecular complexes with different drug carriers: EPC liposome,SBE‐β‐CD and β‐CD

Binary and ternary systems composed of dapsone, sulfobutylether‐β‐cyclodextrin (SBE‐β‐CD), β‐CD and egg phosphatidylcholine (EPC) were evaluated using 1D ROESY, saturation transfer difference NMR and diffusion experiments (DOSY) revealing the binary complexes Dap/β‐CD (K_a 1396 l mol^?1), Dap/SBE‐β‐CD (K_a 246 l mol^?1), Dap/EPC (K_a 84 l mol^?1) and the ternary complex Dap/β‐CD/EPC (K_a 18 l mol^?1) in which dapsone is more soluble. Copyright © 2014 John Wiley & Sons, Ltd.     

Mesure de l'Anisotropie des Indices de Réfraction des Cristaux Liquides: Interpretation des Différences Observées lors de I'Utilisation des Diverses Méthodes

Les différences observées dans la mesure des indices et des biréfrignences dans les cristaux liquides, lors de l'utilisation de deux séries de méthodes: utilisation de cuve prismatique à longueur d'onde fixe ou de cuves à faces parallèles à longueur d'onde variable sont relevées et confirmées.     

Separations of antifungal compounds in capillary electrophoresis with two anionic cyclodextrins

CD‐CZE methods were developed for complete stereoisomeric separations of a series of six γ‐lactam analogues, of which some were neutral, or cationic depending on the background electrolyte nature. The tested cyclodextrin was the versatile sulfobutylether‐ β‐CD, used either in a phosphate buffer using capillaries dynamically coated with polyethylene oxide or in a borate buffer using uncoated capillaries. Long‐end and short‐end modes and concentration variations of chiral selectors allowed finding conditions of complete separation of four out of the six derivatives (i.e., 1 , 2 , 3, and 4 ) in short run times, confirming their broad range of applications. To separate the two last compounds, the highly sulfated‐ γ‐CD was examined as chiral selector in acidic phosphate conditions. The enantiomers of the γ‐lactam analogues 5 and 6 were baseline resolved with 5.5 and 4%, respectively as concentration in the buffer.     

Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed.In this model,the source boundary conditions of the spheroidal beam equation(SBE) for multi-annular phased elements are studied.Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov-Zabolotskaya-Kuznetsov(KZK) model,respectively.Axial dynamic focusing and the harmonic effects are presented.The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field.     

山岳型景区景观审美语义模型研究——以太白山为例

山岳型景区一直是热门旅游目的地之一，关于山岳型景区景观审美的研究目前尚较少见。以太白山为例，从游记文本中提取评判词表，运用美景度评价（SBE）法和语义差别（SD）法分别得到风景照片的美景度值和景观要素测量值，结合因子分析法、多元线性回归法和词频分析法，自下而上构建山岳型景区景观审美语义计算式。研究发现，山岳型景区景观审美由激励性、和谐性、多样性和神秘性4个维度组成，且以激励性、和谐性为主导，反映的是对山岳型景区景观“刚柔疏密共存”的审美要求，其中，“势”之美最为重要，“色”之美多角度影响审美。通过选取合适的观景台位置、植被和建筑材料，提升山岳型景区的旅游体验。     

Combined use of ionic liquid and sulfobutylether‐β‐cyclodextrin as electrolyte additives for separation and determination of camptothecin alkaloids by CZE

This work reported that ionic liquid (IL) ([Bmim] [PF₆]) and sulfobutylether‐β‐CD (SBE‐β‐CD) were used as electrolyte additives for the separation and determination of camptothecin (CPT) alkaloids by CZE. Separation parameters such as the buffer type, pH, and concentration of the running buffer, the concentration of SBE‐β‐CD and IL, temperature, and separation voltage were all investigated in order to achieve the maximum possible resolution. The four analytes were baseline separated within 10 min in capillary at the separation voltage of 15 kV with a running buffer consisting of 20 mM borate buffer, 20 mM IL, and 100 mM SBE‐β‐CD at pH 9.0. Under such conditions, good linearity about two orders of magnitudes of peak areas was achieved for the investigated CPT alkaloids with the correlation coefficients ranging from 0.9946 to 0.9985. For all analytes, detection limits (S/N = 3) and quantitation limits (S/N = 10) range from 0.05 to 0.92 μg/mL and 0.17 to 3.06 μg/mL, respectively. The proposed method has not only been successfully applied to the separation and determination of CPT alkaloids but also showed that IL seemed to be a promising additive in CZE separation.     

Modulation of hydrogen bonding upon ion binding: Insights into cooperativity

The impact due to the of presence of ions, such as Mg²⁺, Na⁺, H⁺, Cl^?, and OH^? on hydrogen bonded clusters of increasing size (water, formamide, and acetamide [n = 1–10]) in the context of associated cooperativity has been explored using density functinal theory (DFT) calculations. Sequential binding energies (SBE) rise on addition of monomer in case of parent clusters. SBE for ionic clusters are several times higher than that of parent clusters initially. This behavior is more dramatic on addition of either Mg²⁺ or H⁺ compared to other ions. Interestingly, SBE of both parent and ionic clusters approach nearly uniform values beyond n = 6 irrespective of kind of ion present in the cluster with the exception of magnesium. © 2013 Wiley Periodicals, Inc.