Towards a Mechanism Underlying the Stability of the Tetragonal CuO Phase： Comparison with NiO and CoO by Hybrid Density Functional Calculation

By means of hybrid density functional theory, we interpret the stability mechanism of the tetragonal CuO phase, which was synthesized using the pulsed laser deposition. The orbital ordering resulted from the crystal field splitting is found to be favorable for the do electronic configuration of the Cu2＋ ion, yielding two possible metastable tetragonal phases （c/a 〈 1 and c/a 〉 1） of CuO. A detailed comparison is also performed with the ideal rock-salt compounds CoO and NiO.     

A review of electrocatalyst characterization by transmission electron microscopy

At present, the development of highly efficient electrocatalysts with more rational control of microstructures(e.g. particle size, morphology, surface structure, and electronic structure) and chemical composition is needed and remained great challenges. Transmission electron microscopy(TEM) can offer the information about the microstructures and chemical compositions of the electrocatalysts on nano and atomic scale, which enables us to establish the synthesis-structure-performance relationship and further direct the design of new electrocatalysts with high performance. In this minireview paper, a brief introduction on the basic characterization of electrocatalysts with TEM, followed by the studying of dynamic evolution of the electrocatalysts in electrochemical reactions with identical location-TEM, is discussed.     

Synthesis of a diastereomeric mixture of deuterium-labeled lovastatin and its acid ammonium salt

In this communication, a facile synthesis for (2S/2R)-[²H₃]lovastatin and (2S/2R)-[²H₃]lovastatin acid ammonium salt was described. The stable isotope-labeled (2S/2R)-lovastatin and its acid ammonium salt were prepared from butyric acid via several reaction steps with 11.1 and 6.3 % overall yield, respectively.     

Water repellent/wetting characteristics of various bio-inspired morphologies and fluid drag reduction testing research

It is well-known that the bio-inspired sharkskin covering the original pattern has the apparent drag reduction function in the turbulent flowing stations, which can be regarded as “sharkskin effect”, and it has progressively been put application into the fluid engineering with obtaining great profits. In this paper, the anisotropic wetting phenomena on sharkskin are discovered, the contact angles and rolling angles on different orientations are not the same. In addition, the hydrodynamic experiments on different sharkskin surfaces are conducted, and the experimental results illustrate that the super-hydrophobic and drag-reducing properties on deformed biological surfaces are improved to some extent compared to the original morphology, which has important significance to expand its practical applications.     

5-羧甲基-7-羟基-2-甲基色原酮核磁共振研究

从虎杖(Polygonum cuspidatum Sieb.et Zucc.)抗菌抗炎有效部位中分离得到一化合物：5-羧甲基-7-羟基-2-甲基色原酮. 首次利用2D-NMR技术对其核磁共振信号进行了确切归属.     

A New Glucuronidated Metabolite of Andrographolide in Human

A new andrographolide metabolite 1 was isolated from human urine samples after oral administration. The structure was determined to be 3-carbonylandrographolide-19-O-β-D-glucuronide on the basis of chemical evidences and spectral analysis, especially by 2D-NMR techniques.     

High-performance liquid chromatographic method for the determination and pharmacokinetic study of mangiferin in plasma of rats having taken the traditional Chinese medicinal preparation Zi-Shen pill

A high-performance liquid chromatographic method for the determination and pharmacokinetic study of mangiferin in the plasma of rats that have been orally administered the traditional Chinese medicinal preparation Zi-Shen pill is established. Plasma samples taken from rats are pretreated by protein precipitation with acetonitrile. Separation of the main effective constituent mangiferin is accomplished on a C18 stationary phase and a mobile phase of methanol&-water (25:75, v/v) with 0.6% glacial acetic acid. The UV detection wavelength is set at 320 nm, and the detection limit for mangiferin in plasma is 0.163 micro g/mL. After validation, the method is used to take a limited view of pharmacokinetic profiles of the traditional Chinese medicinal preparation Zi-Shen pill.     

Study on the bioavailability of puerarin from Pueraria lobata isoflavone self-microemulsifying drug-delivery systems and tablets in rabbits by liquid chromatography-mass spectrometry

To evaluate the bioavailability of puerarin from Pueraria lobata isoflavone self-microemulsifying drug delivery systems (SMEDDS) and Yufengningxin tablets, a rapid and specific liquid chromatography--mass spectrometric method was developed and validated to determine puerarin in rabbit serum. The analyte was extracted from serum samples by precipitating the serum proteins, separated on a Diamonsil C(18) column and detected by mass spectrometry with an electrospray ionization interface. 4-Hydroxybenzaldehyde was used as the internal standard. The method has a limit of quantitation of 10 ng/mL using 200 microL serum. The intra-day relative standard deviations (RSDs) ranged from 3.7 to 6.9% and inter-day RSDs were within 6.5%. After administration of SMEDDS and tablets to rabbits, a significant difference was observed in main pharmacokinetic parameters of t(max), C(max) and AUC(0--infinity) between SMEDDS and tablets, and a 2.2-fold increase in the relative bioavailability of puerarin was observed with the SMEDDS compared with Yufengningxin tablets. It was concluded that the absorption of puerarin from Pueraria lobata isoflavone SMEDDS was enhanced.     

Two new saponins from Anemarrhena asphodeloides Bge.

Two new saponins 3-O-β-D-glucopyranosyl (1→2)-β-D-mannopyranosyl sarsasapogenin, named timosaponin A IV(1) and (5β, 25S)-26-O-β-D-glucopyranosyl-furost-20(22)-en-3,26-diol-3-O-β-D-glucopyranosyl (1→4) glucopyranosyl (1→2)-β-D-galacopyranoside, named timosaponin B IV(2), were isolated by silica gel column chromatography and preparative HPLC from Anemarrhena asphodeloides Bge. Their structures were elucidated by chemical characters and spectroscopic analysis.