Preparative separation of minor saponins from Platycodi Radix by high-speed counter-current chromatography

Platycosides (PSs), the saponins found in the root of Platycodon grandiflorum (Jacq.) A. DC. (Platycodi Radix), are typically composed of oleanene backbones with two side chains; one is a 3-O-glucose linked by a glycosidic bond, and the other is a 28-O-arabinose-rhamnose-xylose-apiose linked by an ester bond. Minor saponins, acetylated isomers of the major saponin on either the 2' or 3' position of rhamnose, were isolated from Platycodi Radix using a multi-step process including high-speed counter-current chromatography (HSCCC) and preparative reversed-phase high-performance liquid chromatography (RP-HPLC). After the separation of the major components, the enriched minor saponin fraction was used for this study. A two-phase solvent system consisting of chloroform-methanol-isopropanol-water (3:2:2:3, v/v) was used for HSCCC. HSCCC separation of the enriched minor saponin fraction yielded 2'-O-acetylplatycodin D, 3'-O-acetylpolygalacin D, 2'-O-acetylpolygalacin and a mixture of 3'-O-acetylplatycodin D and polygalacin D. The mixture fraction from HSCCC separation was further purified by preparative RP-HPLC, giving 3'-O-acetylplatycodin D and polygalacin D at a purity of over 98.9%. The developed method provides the preparative and rapid separation of minor saponins in the crude extract of Platycodi Radix. To the best of our knowledge, this is the first on the separation of acetylated PSs by HSCCC.     

试析赫梯人进入小亚细亚的途径

印欧种赫梯人迁入小亚细亚的途径主要有两种说法，即高加索说和海峡说。然而，在对高加索山区及周边地区的气候、自然地理环境和古代交通，马的驯化和车辆的发明，以及一些考古材料等进行研究之后，可以认为高加索说更为合理一些。     

沉管灌注桩防止颈缩的措施探讨

本文根据临汾地区具有代表性的工程地质对影响灌注桩质量的原因进行了分析，并提出了防止颈缩的措施。     

The ultrasound application does not affect to the thermal properties and chemical composition of virgin olive oils

In this work, the effects of high power ultrasound treatment (40 kHz) on virgin olive oil (VOO) for different times (0, 15, 30 min) were studied, in order to verify if extent modifications in their chemical composition and thermal properties. The effects of the different ultrasound treatments on VOOs were determined considering the following parameters: quality index (free acidity, K₂₃₂ and K₂₇₀), lipid profile (fatty acids and triglycerides composition) minor components (phenols, tocopherols, pigments and volatiles) and thermal properties (crystallization and melting) by Differential Scanning Calorimetry (DSC).During the ultrasound treatments, bubbles growth was present in the VOO due to the phenomenon of cavitation and a slight increase of the temperature was observed. In general, the ultrasound treatments did not cause alterations on VOO parameters evaluated (oxidation state, lipid profile, minor components and thermal profiles). However, a slight decrease was observed in some volatile compounds.     

铸造方法对巴氏合金组织及性能的影响

铸造方法对巴氏合金的力学及磨损性能有显著的影响。通过对合金的金相组织观察、相成分的分析，结合磨损试验以及磨损表面形貌分析，研究铸造方法对合金的组织及性能的影响。分析发现离心浇注能明显的细化晶粒，提高合金的耐磨性与减磨性，与静置浇注的合金相比，其磨损量下降了9．6％。     

镁质中间包绝热板的研制

介绍一种新型隔热耐火材料，该板用ＭｇＯ＞９５％的烧结镁砂和Ａ１２Ｏ３＞３８％的漂珠为主要原料，以及适量的纤维、结合剂、添加剂研制出的体积密度１．４６ｇ／ｃｍ３，导热系数０．４６Ｗ／ｍ·Ｋ，抗折强度６ＭＰａ的镁质绝热板。     

Treatment of sulcus vocalis: Auditory perceptual and acoustical analysis of the slicing mucosa surgical technique

Sulcus vocalis is a furrow in the mucosa of the vocal folds that causes glottic insufficiency, irregular vibrations, and a distinctive dysphonia of variable severity. Treatment of sulcus vocalis needs to achieve anatomical and functional improvements that satisfy the behavior of the larynx and vocal quality. We suggest a combined approach, which includes vocal fold mucosal surgery through a technique called slicing mucosa, followed by intensive vocal rehabilitation. The aim of the surgery is to detach the mucosa of the sulcus and to interrupt the longitudinal fibrotic tension lines. The results of this procedure in 10 patients were analyzed through visual, auditory, and acoustical methods, and the data lead us to conclude that the treatment proposed offered a good anatomical result, a better vibratory pattern, and an improvement in overall vocal quality.     

Extremal infinite graph theory

We survey various aspects of infinite extremal graph theory and prove several new results. The lead role play the parameters connectivity and degree. This includes the end degree. Many open problems are suggested.     

A well-quasi-order for tournaments

A digraph H is immersed in a digraph G if the vertices of H are mapped to (distinct) vertices of G, and the edges of H are mapped to directed paths joining the corresponding pairs of vertices of G, in such a way that the paths are pairwise edge-disjoint. For graphs the same relation (using paths instead of directed paths) is a well-quasi-order; that is, in every infinite set of graphs some one of them is immersed in some other. The same is not true for digraphs in general; but we show it is true for tournaments (a tournament is a directed complete graph).