Fermentation characteristics and the dynamic trend of chemical components during fermentation of Massa Medicata Fermentata

As a representative of traditionally fermented Chinese medicine, Massa Medicata Fermentata (MMF) shows the functions of invigorating the spleen and stomach and promoting digestion, which plays an important role in the treatment of gastrointestinal diseases. The fermentation mechanism and the key factors that affect the quality of MMF have not been revealed yet, which has become an urgent issue that limits its clinical application. This article aims to systematically and comprehensively reveal the transformation of physical properties and the dynamic trend of chemical components including substrate components, volatile components, and lactic acid as anaerobic fermentation product during MMF fermentation. Along with obvious hyphae growth observed for MMF, the weight of MMF decreased, and the moisture and temperature increased. Through the quantified 14 components from substrate, ferulic acid increased from 45.53 ± 6.94 to 141.89 ± 78.40 μg/g, while glycosides and phenolic acids declined except caffeic acid. Also, within the 66 volatile components analyzed, alcohols and acids increased, while aldehydes and ketones decreased. Lactic acid was not detected in the fermentation substrate, but an apparent increase in lactic acid content was observed along with the increased fermentation days, resulting in 2.54 ± 0.15 mg/g on day 8. Based on the tested components, the fermentation process of MMF was discriminated into three distinct stages by principal component analysis, and an optimal fermentation time of four days was proposed. The results of this study will be of great significance to clarify the characteristics of fermentation and conduce to improving quality standards of MMF.     

高维稳健主成分聚类方法及其应用研究

随着信息技术的高速发展,每条数据所包含的信息越来越丰富,使得数据不可避免地含有异常值,且随着维数的增加,异常值出现的可能性更大。传统的主成分聚类分析对异常值特別敏感,基于MCD估计的主成分聚类方法虽然对异常值具有防御作用,但是在高维数据下MCD估计的偏差过大,其稳健性显著降低,而且当维数大于观测值个数时MCD估计失效。为此本文提出了基于MRCD估计的稳健主成分聚类方法,数值模拟和实证分析表明,基于MRCD估计的主成分聚类分析的效果优于传统的主成分聚类分析和基于MCD估计的主成分聚类分析,尤其是在维数大于样本观测值的情况下,MRCD估计更为有效。     

pH滴定-主成分回归法同时测定酚类同系物

本文利用pH滴定－主成分回归法同时测定了苯酚、邻苯二酚、邻苯三酚的混合物，结果良好。通过交差验证法，本文还对采样区间和采样间隔作了详细讨论。     

Simultaneous kinetic determination of thiocyanate and sulfide using eigenvalue ranking and correlation ranking in principal component-wavelet neural network

In this work, two toxic compound, sulfide and thiocyanate were determined simultaneously using kinetic spectrophotometry. These anions have shown the catalytic effects on the reaction between iodine and azide. Since the system was nonlinear, a nonlinear model, principal component-wavelet neural network (PC-WNN) was used as the multivariate calibration method. The principal component analysis was used to decrease the dimension of the original matrix. In other words, the scores of the PCs, 5, instead of the original variables, 301, were used as the input for the model. Two methods were used to select the most relevant principal components: eigenvalue ranking and correlation ranking. In this work, eigenvalue and correlation ranking methods have shown better results for thiocyanate and sulfide, respectively, and it can be concluded that these methods are complementary. The WNN has several advantages relative to other types of neural network such as better convergence ability. The data set was divided to calibration, prediction and validation sets. Each set was selected so that the concentrations of the analytes were approximately covered the entire ranges of the analytes. Mean relative error for thiocyanate and sulfide in validation set were 8.5 and 10.6, respectively. Thiocyanate and sulfide can be determined in the range of 60–700 ng ml⁻¹ and 20–400 ng ml⁻¹, respectively. The proposed method was applied for the determination of sulfide and thiocyanate in real samples such as tap, waste and river waters with satisfactory results.     

Implementation and efficiency of an automatic peak-purity-control procedure in HPLC-UV-VIS-coupling based on principal component analysis

Summary Based on a thorough knowledge of the actual system precision significance testing of the primary eigen values, resulting from principal component analysis of the two-dimensional data array of HPLC with photodiode-array detection, is a powerful means to uncover unresolved chromatographic peaks. The implementation of this chemometric technique for assuring peak homogeneity and results showing the efficiency for two-component peaks in regard to spectral characteristics, chromatographic resolution and absorbance ratio of the investigated compounds are presented.     

Structural Features of Solid Phases and Topology of Phase Diagrams

The paper considers model phase diagrams of binary and ternary systems involving transformations (transitions) of phase equilibria. The relationship between the type of structural solidstate transformation and the type of phase diagram is shown. Topological series of phase diagrams of systems with continuous and limited types of solid solutions are considered, including phase diagrams with polymorphic transitions between intermediate solid phases of variable composition.     

主成份分析-偏最小二乘法分光光度法同时测定钴、镍、铜、锌四组份体系

用 PCA 及 PLS 分步处理分光光度数据,有效降低了计算的维数。以该法对不同酸度体系的5-Br-PADAP-钴、镍、铜、锌分光光度数据进行了处理,定量分析结果良好。     

Interaction of cubosomes with plasma components resulting in the destabilization of cubosomes in plasma

Cubosomes are novel dispersed nanoparticles with bicontinuous cubic phases of monoolein in their interior. We investigated their disintegration process in plasma by in vitro and in vivo studies. Cubosomes were incubated with whole plasma or plasma components such as HDL, LDL, and albumin. The lypolysis study indicated lipolytic activity of whole plasma towards cubosomes. Gel filtration chromatography revealed that HDL, LDL and albumin interacted with cubosomes. HDL affected cubosomes’ integrity and gave rise to smaller particles which contained the components of both cubosomes and HDL. Upon incubation with LDL, cubosomes fused with LDL. Albumin was shown to take up monoolein out of the particles. Cubosomes were disintegrated by whole plasma as a result of the interaction with plasma components. It was concluded that in vivo observation of a long circulation time of a hydrophobic substance in cubosomes was due to the sustained behavior of cubosome remnant particles.     

Error estimation in peak‐shape analysis of XPS core‐level spectra using UNIFIT 2003: how significant are the results of peak fits?

An error analysis for numerically evaluating random uncertainties in x‐ray photoelectron spectroscopy has been implemented in version 2003 of the spectra treatment and analysis software UNIFIT in order to improve the understanding of the statistical basis and the reliability of the model parameters for photoelectron spectra. The theoretical basis as well as two approaches to obtain error limits of the fit parameters have been considered. Several test spectra have been analysed and discussed. A representative example has been chosen to demonstrate the relevance of the error estimation for practical surface analysis. Suggestions for the minimization of errors in the peak‐fitting procedures are presented. Copyright © 2004 John Wiley & Sons, Ltd.     

凝胶过滤色谱法测定泥鳅多糖的组成及分子量

从泥鳅粘液中分离提取到中性的粗多糖 ,采用凝胶过滤色谱柱在高效液相色谱仪上进行分离和测定 ,结果表明 ,该多糖由一个高聚糖 (MAP ,19 1% )和一个寡糖 (MAO ,80 9% )组成。用标准的Pullulan(P 112 0 0 0 ,P 4 730 0 ,P 2 2 80 0 ,P 5 90 0 ,P 2 70 0 )作标准曲线 ,测得其重均分子量分别为 130 2 5 2 (约 72 3个糖基 )和 15 39(约 9个糖基 )。粗多糖经SephadexG 10 0凝胶柱 (1cm× 5 0cm)过滤 ,分离得到纯化的MAP和MAO。