A simple approach to the prediction of soil sorption of organophosphorus pesticides.

Organophosphorus pesticides (OP) affect the crops and environments, and the reliable approach to the prediction of soil sorption of pesticides is required. In this respect, we proposed a simple Chemometrics approach, in which the Tchebichef image moment (TM) method was used to extract useful information from the greyscale images of molecular structures and the quantitative model was established by stepwise regression to predict the soil sorption of OPs. Different squared correlation coefficients including the leave-one-out cross-validation (LOO-CV) () that concerns the training set and the () which concerns the external independent test set are more than 0.

A simple approach to the determination of three curcuminoids with similar chemical structures in different substrates.

The determination of curcuminoids in mixtures is more difficult due to their similar chemical structures as well as serious interferences, thus the complex pretreatments of samples and the optimization of experimental conditions are often required. Here, owing to the mathematical separation of chemical signals by Tchebichef image moments, a simple and effective approach to the simultaneous quantitative analysis was proposed, and applied to the determination of the three curcuminoids in turmeric and curry based on their raw fluorescence 3D spectra. For the established linear models, the leave-one-out correlation coefficients ( ) were more than 0.

Chemometrics-assisted simultaneous voltammetric determination of multiple neurotransmitters in human serum.

An electrochemical method combining chemometrics was developed for simultaneous quantification of multiple neurotransmitters including Dopamine (DA), Epinephrine (EP), Norepinephrine (NE) and serotonin (5-hydroxytryptamine, 5-HT) in human blood serum. A reduced graphene oxide modified glassy carbon electrode (RGO/GCE) was prepared via electrodeposition method. Differential pulse voltammetry (DPV) measurement of the four neurotransmitters showed that the voltammetric signals of the four targets overlapped significantly.

An effective approach to the early diagnosis of colorectal cancer based on three-dimensional fluorescence spectra of human blood plasma.

Colorectal cancer (CRC) is a common malignancy in the gastrointestinal tract, and its screening rates remain relatively low in the general population due to the lack of specific symptoms and effective methods. It is still in urgent need to develop rapid and reliable approach to the early diagnosis of CRC. Herein, based on the three-dimensional (3D) fluorescence spectra of human blood plasma, a combination strategy of Tchebichef image moments coupled with partial least squares-discriminate analysis (TM-PLS-DA) was proposed for the detection of CRC from three classes (CRC samples, adenomas samples and non-malignant findings).

One-pot facile synthesis of CuNCs/RGO nanocomposite for the sensitive detection of heparin in human serum samples.

A simple and facile one-pot approach for the synthesis of copper nanoclusters decorated reduced graphene oxide (CuNCs/RGO) nanocomposite was proposed, in which the CuNCs attached to the surface of the reduced glutathione (GSH) functionalized RGO through ligand exchange via their thiol functionalities. The synthesized nanocomposite was verified by structural characterizations, and the further investigation of density functional theory (DFT) indicated that CuR cluster (R = CHONS) with the lowest energy was the most stable structure in GSH-capped CuNCs. Although the CuNCs/RGO nanocomposite exhibited rather weak fluorescence, with the addition of heparin (Hep), the significant enhancement of fluorescence at 595 nm was achieved, which was developed to detect Hep in human serum samples with high selectivity and sensitivity.

A Simple Approach to the Toxicity Prediction of Anilines and Phenols Towards Aquatic Organisms.

Chemicals pollution in the environment has attracted attention all over the world, and the toxicity prediction of chemical pollutants has become quite important. In this paper, we introduce a simple approach to predict the toxicity of some chemical components, in which the Tchebichef image moment (TM) method was employed to extract useful chemical information from the images of molecular structures to establish quantitative structure-activity relationship (QSAR) prediction models. The proposed approach was applied to predict the toxicity of anilines and phenols for the aquatic organisms of P.

The activity prediction of indole inhibitors against HCV NS5B polymerase.

Non-structural viral protein 5B (NS5B) is a viral protein in hepatitis C virus. Although various inhibitors against NS5B have been found, the activity prediction of similar untested inhibitors is still highly desirable. In this respect, the Tchebichef moments (TMs) calculated from the images of molecular structures were regarded as the independent variables while the inhibitory activity (pIC ) was the dependent variable, and the predictive model was established by means of stepwise regression.

Applications of Discrete Shmaliy Moments on the Quantitative Analysis of Multitarget Compounds Based on the Chemical Spectra.

To extract the features in first-order or second-order signals, the two kinds of discrete Shmaliy moment (DSM) methods were proposed and applied to the quantitative analysis of multitarget compounds in complexes based on the UV-vis and high-performance liquid chromatography with pulsed amperometric detector (HPLC-PAD) spectra of samples for the first time. All the statistical parameters demonstrated that the obtained models were accurate and the established analytical methods were reliable, even in the presence of a different degree of overlapping signals as well as various interferences. Compared with Tchebichef moment (TM) and other classical methods such as multivariate curve resolution-alternating least-squares (MCR-ALS), partial least-squares (PLS) regression, and N-way partial least-squares (N-PLS), the proposed methods are more convenient and efficient, which not only provides another suitable tool for the quantitative analysis of multitarget components in complex samples but also extends the application of moment invariants in chemical signal analyses.

Simultaneous quantification of multiple endogenous biothiols in cancer cells based on a multi-signal fluorescent probe.

Although a large number of fluorescent probes have been developed, the simultaneous quantitative analysis of intracellular thiols is still difficult due to the spectral overlap and the complexity of the intracellular environment. In this study, a multi-signal fluorescent probe was employed for the simultaneous quantification of intracellular glutathione (GSH), cysteine (Cys) and homocysteine (Hcy). As the feature variables of the target components, the Tchebichef image moments (TMs) calculated from the grayscale images of the 3D fluorescence spectra were used to establish the quantitative linear models by stepwise regression.

The rapid quantitative analysis of three pesticides in cherry tomatoes and red grape samples with Tchebichef image moments.

Diverse interferences often affect the determination of pesticide residues in various kinds of food, and complex pretreatments are necessary. An effective approach for the simultaneous quantitative analysis of multi-target components in different substrates was proposed, and applied to the determination of ternary pesticides in cherry tomatoes and red grape samples. By means of HPLC-DAD, the spectra were obtained under isocratic elution.