A simple method for extracting both active oily and water soluble extract (WSE) from Nigella sativa (L.) seeds using a single solvent system

The current study provides a way of extraction for both active NSO and WSE from Nigella sativa seeds using 98% methanol. About 1?kg of ground seeds was macerated by 1:2.5 w/v (g/mL) for 72?hours. After rotary evaporation and 7 days of continuous drying and chilling at 50 and 4?°C, NSO and WSE were obtained at the same instant. Solubility tests of 24 solvents and 11 thin layer chromatographic analyses while 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging assay of NSO (73.66) , WSE (33.32) and NSO?+?WSE (78.22) against ascorbic acid (IC50?=?4.28?mg/mL) was performed. WSE was found to be highly soluble in water and 5% NaOH exhibiting the same Rf value of 0.95 for EtOH:DMSO (9:1) against the honey. WSE has revealed more than twofold higher anti-oxidant activity than others. Formulation of WSE with Tualang honey may provide better targeted hydrophilic drug delivery systems.     

Transition metal impurities in wide gap materials: are the electronic properties well described through the ligand field theory?

In the traditional ligand field theory the electronic properties due to a transition metal (TM) impurity, M, in an insulator are explained only in terms of the MX _N complex formed with the N nearest anions. This work is aimed at emphasizing the role played by the electrostatic potential, V _R (r), exerted by the rest of lattice ions upon the localized electrons of the TM complex. This potential, neglected in the traditional ligand field theory, is shown to play a key role when comparing the electronic properties of the same TM complex but embedded in two lattices which are not isomorphous even if both are cubic. As a relevant example it is shown that the different 10 Dq values exhibited by in the normal perovskite KMgF₃ (10 Dq = 14,100 cm⁻¹) and in the inverted perovskite BaLiF₃ (10 Dq = 16,720 cm⁻¹) can hardly be understood only through a distinct Cr³⁺–F⁻ distance. In contrast such a difference is shown to come mainly from the different shape of V _R (r) in these two cubic lattices. the importance of this internal electric field is pointed out to grow when comparing two host lattices with the same ligand and coordination number but very different symmetry. This situation is found in the case of ruby (Al₂O₃ : Cr³⁺) and emerald (Be₃Si₆Al₂O₁₈ : Cr³⁺) where V _R (r) is behind the different colours exhibited by such gemstones. For the sake of clarity a brief discussion on the foundations of the ligand field theory is reported in the present work as well. Contribution to the Serafin Fraga Memorial Issue.     

Second harmonic generation by micropowders: a revision of the Kurtz–Perry method and its practical application

We theoretically study the second harmonic generation by powder crystal monolayers and by thick samples of crystalline powder with particle size in the range of microns. Contrary to usual treatments, the light scattering by the particles is explicitly introduced in the model. The cases of powder in air and in an index-matching liquid under the most common experimental geometries are considered. Special attention is paid to the possibility of determining the value of some nonlinear optical coefficients from the experiments. The limitations and shortcomings of the classical Kurtz and Perry method (Kurtz and Perry in J Appl Phys 39:3798, 1968) and the most common practical misuses of it are discussed. It is argued that many of the experimental works based on that method oversimplify the technique and contain important errors. In order to obtain reliable values of the nonlinear coefficients, an appropriate experimental configuration and analysis of the data are pointed out. The analysis is especially simple in the case of uniaxial phase-matchable materials for which simple analytical expressions are derived.     

高聚合度Ⅱ-型聚磷酸铵的合成

用聚合反应-热处理两段工艺合成了高聚合度的聚磷酸铵（APP）阻燃材料,其结构经XRD,粒度及平均聚合度表征。优化反应条件为：磷酸氢二铵1mol,n（磷酸氢二铵）：n（五氧化二磷）：n（脲）：1．0：1．0：0．3．干燥氨气氛下于290℃反应30min,再经250℃-280℃后处理100min-110min。APP的平均聚合度大于150,粒度小于50μm。     

Charge transfer within zintl ions in liquid metallic alloys. A cluster study

Self-consistent field multiple scattering X calculations of the electronic structure of Na₄Pb₄, K₄Pb₄ and Rb₄Ph₄ clusters have been performed in order to investigate the charge transfer process from the alkali atoms to the lead atoms. The structure assumed is that of an inner Pb₄ tetrahedron surrounded by another, larger tetrahedron in which the alkali atoms take positions opposite to the faces of the Pb₄ unit. The total charge transfer to Pb₄ is about two electrons, half the amount normally assumed in the Zintl ion model of these clusters in solid and liquid alloys.     

Asteriscanolide. A sesquiterpene lactone with a new natural skeleton.

A sesquiterpene lactone was isolated from the hexane extract of $\text{Asteriscus aquaticus}$. Its constitution and stereochemistry were determined by spectroscopic techniques, principally two-dimensional NMR correlations (COSY, HCCORR, RELAY) and with the interpretation of certain chemical transformations. The results were confirmed by X-ray diffraction and the name asteriscane is proposed for the new natural skeleton.