Synthesis, Anti-inflammatory Activities and Mechanisms of 3,5- dihydroxycinnamic Acid Derivatives.

Background: 3,4-dihydroxycinnamic acid and its derivatives exhibit numerous biologic activities. Such activities have not previously been reported for 3,5-dihydroxycinnamic acid derivatives. In this study, ten derivatives of 3,5- dihydroxycinnamic acid were synthesized and their anti-inflammatory activities were tested in 12-O-tetradecanoylphorbol 13-acetate-induced mouse ear edema.

Combining the least correlation design, wavelet packet transform and correlation coefficient test to reduce the size of calibration set for NIR quantitative analysis in multi-component systems.

The paper focuses on solving a common and important problem of NIR quantitative analysis in multi-component systems: how to significantly reduce the size of the calibration set while not impairing the predictive precision. To cope with the problem orthogonal discrete wavelet packet transform (WPT), the least correlation design and correlation coefficient test (r-test) have been combined together. As three examples, a two-component carbon tetrachloride system with 21 calibration samples, a two-component aqueous system with 21 calibration samples, and a two-component aqueous system with 41 calibration samples have been treated with the proposed strategy, respectively.

The spatial effect of near-infrared spectroscopy and its application to the study of supramolecular chemistry.

An unlooked-for experimental observation that in near-infrared spectroscopy (NIR) the absorption peak of the second overtone of aniline adsorbed by 13X molecular sieve nearly disappeared led us investigate a fundamental question: the behavior of NIR when the outside space surrounding a molecule is too small to allow the molecule to vibrate freely. Through NIR of various organic compounds adsorbed by different porous inorganic materials like 13X molecular sieve, silica gel and active aluminium oxide, and NIR of supramolecular cyanuric acid-melamine, we can reasonably confirm a theoretical inference that in the micro-environment above, all intensities of NIR absorbance decrease, and the second overtone decreases more than the first overtone does. Furthermore, one distinct feature of NIR, higher sensitivity to the size of micro-environmental space as compared with mid-infrared (MIR), and its potential application to the study of supramolecular structure are outlined by our experiments.

Determination of psoralen in human plasma using excitation-emission matrix fluorescence coupled to second-order calibration.

A new algorithm, an alternating normalization-weighted error (ANWE) method, and the parallel factor analysis (PARAFAC) have been used to directly determine psoralen (PSO) in human plasma. The two methods fully exploit the second-order advantage of the applied three-way fluorescence data. Interestingly, the calibration samples need only the components of interest, and the prediction samples allow containing not only the components of interest, but also unknown interferents.

Using near-infrared spectroscopy and differential adsorption bed method to study adsorption kinetics of orthoxylene on silica gel.

This paper has demonstrated the study on the adsorption kinetics of orthoxylene on silica gel with a novel experimental methodology. In the method, there was a differential adsorption bed (DAB) where the solid adsorbent always contacted with the same bulk concentration of the adsorbate vapor, and the DAB was monitored with near-infrared diffuse reflectance spectroscopy (NIRDRS) continuously as well as non-invasively. Local partial least squares (PLS) algorithm was suggested to replace normal global PLS method in multivariate calibration models for processing NIRDRS data, because the concentration of the adsorbate on the adsorbent varied greatly as the adsorption process was going on.

Simultaneous determination of 6-methylcoumarin and 7-methoxycoumarin in cosmetics using three-dimensional excitation-emission matrix fluorescence coupled with second-order calibration methods.

This paper reports a simple, rapid, and effective method for quantitative analysis of 6-methylcoumarin (6-MC) and 7-methoxycoumarin (7-MOC) in cosmetics using excitation-emission matrix (EEM) fluorescence coupled with second-order calibration. After simple pretreatments, the adopted calibration algorithms exploiting the second-order advantage, i.e.

Determination of pesticides in honey using excitation-emission matrix fluorescence coupled with second-order calibration and second-order standard addition methods.

The present paper presents a novel method for simultaneous determination of the three pesticides, carbaryl, carbendazim and 1-naphthol in honey. The excitation-emission matrix fluorescence data from calibration and prediction samples composed a three-way data array and then were analyzed using the second-order calibration method based on the self-weighted alternating trilinear decomposition (SWATLD). The second-order advantage of the SWATLD-based second-order calibration method was exploited, which makes it possible that calibration can be performed even in the presence of unknown interferences.

Quantitative analysis of hydrolysis of carbaryl in tap water and river by excitation-emission matrix fluorescence coupled with second-order calibration.

A novel method was proposed to determine simultaneously carbaryl and its degradation product 1-naphthol in river and tap water in this paper. The parallel factor analysis (PARAFAC) algorithm was adopted to analyze the excitation-emission matrix (EEM) fluorescence data. The second-order advantage of the PARAFAC-based second-order calibration algorithm was exploited, which make it possible that calibration can be performed even in the presence of unknown interferences.

An ensemble of Monte Carlo uninformative variable elimination for wavelength selection.

An improved method based on an ensemble of Monte Carlo uninformative variable elimination (EMCUVE) is presented for wavelength selection in multivariate calibration of spectral data. The proposed algorithm introduces Monte Carlo (MC) strategy to uninformative variable elimination-PLS (UVE-PLS) instead of leave-one-out strategy for estimating the contributions of each wavelength variable in the PLS model. In EMCUVE wavelength variables are evaluated by different Monte Carlo uninformative variable elimination (MCUVE) models.

Study of the interactions of berberine and daunorubicin with DNA using alternating penalty trilinear decomposition algorithm combined with excitation-emission matrix fluorescence data.

Studies of interactions between drugs and DNA are very interesting and significant not only in understanding the mechanism of interaction, but also for guiding the design of new drugs. However, until recently, mechanisms of interactions between drug molecules and DNA were still relatively little known. It is necessary to introduce more simple methods to investigate the mechanism of interaction.

Determination of carbendazim in bananas by excitation-emission matrix fluorescence with three second-order calibration methods.

A novel method for determination of carbendazim in bananas is proposed in this study. After the bananas were simply extracted, the carbendazim was quantified under the interference of banana extract using the second-order calibration algorithms based on the parallel factor analysis (PARAFAC), the self-weighted alternating trilinear decomposition (SWATLD) and the alternating penalty trilinear decomposition algorithms (APTLD), respectively. For analysis of the complex samples, the so-called second-order advantage was adequately exploited and good results were obtained.

A novel efficient way to estimate the chemical rank of high-way data arrays.

A novel method, a subspace projection of pseudo high-way data array (SPPH), was developed for estimating the chemical rank of high-way data arrays. The proposed method determines the chemical rank through performing singular value decomposition (SVD) on the slice matrices of original high-way data array to produce a pseudo high-way data array and employing the idea of the difference of the original truncated data set and the pseudo one. Compared with traditional methods, it uses the information from eigenvectors combined with the projection residual to estimate the rank of the three-way data arrays instead of using the eigenvalue.

Interference-free determination of Sudan dyes in chilli foods using second-order calibration algorithms coupled with HPLC-DAD.

This paper presents a new method for the determination of Sudan dyes contained in hot chilli samples. The method employs second-order calibration algorithms to handle the recorded data. The second-order calibration algorithms are based on the popular parallel factor analysis (PARAFAC), alternating trilinear decomposition (ATLD) and self-weighted alternating trilinear decomposition (SWATLD), respectively.

Estimating the chemical rank of three-way data arrays by a simple linear transform incorporating Monte Carlo simulation.

Estimating an appropriate chemical rank of a three-way data array is very important to second-order calibration. In this paper, a simple linear transform incorporating Monte Carlo simulation approach (LTMC) to estimate the chemical rank of a three-way data array was suggested. The new method determines the chemical rank through performing a simple linear transform procedure on the original cube matrix to produce two subspaces by singular value decomposition.

Fluorescence determination of metoprolol in human plasma by trilinear decomposition-based calibration techniques.

In this study a new spectrofluorimetric method for the direct determination of metoprolol in human plasma is presented and discussed. It is based on the use of fluorescence excitation-emission matrices (EEMs) and second-order calibration performed with parallel factor analysis (PARAFAC) or alternating trilinear decomposition (ATLD). This methodology enables accurate and reliable discrimination of the analyte signal, even in the presence of unknown and uncalibrated fluorescent component(s), which is often referred to as the second-order advantage.