ABSTRACT
Objective: To explore the change rules of active ingredients in Phyllanthi Fructus of different storage years,in order to provide theory basis for storage. Method: Seven Phyllanthi Fruatus samples of different storage years were collected. HPLC-UV detection method was established to determine the contents of gallic acid,corilagin,chebulagic acid,ellagic acid and quercetin. Samples were fingerprinted by FT-NIR and identified by PLS-DA model. Result: Gallic acid,which was the bioactive marker in Chinese Pharmacopoeia,had the highest content. It was followed by ellagic acid and chebulagic acid,and corilagin and quercetin had the least content. The components had significant differences between samples of different storage years (P-1 respectively. The contents of chebulagic acid,corilagin and ellagic acid reached a maximum at 4 years of storage,which were 18.85,7.97,21.46 mg·g-1,respectively. FT-NIR data was optimized by MSC+SG (second derivative, the window parameter as 11,and the polynomial order as 3). The classification accuracy was 84.5%. Spectral data reduced to several important potential variables,and was fused with 5 active components based on minimum cross-validation root mean square error,and the classification accuracy increased to 98.8%. Conclusion: The analysis of PLS-DA by HPLC-UV and FT-NIR could effectively explain the accumulation characteristics of active components in Phyllanthi Fruatus. According to the data fusion strategy,PLS-DA model could distinguish samples of different qualities. The results provide a scientific basis for the quality evaluation and identification of Phyllanthi Fruatus.
ABSTRACT
A non-destructive optical method based on near-infrared spectroscopy has been used for the evaluation of litchi fruit quality. Diffuse reflectance measurements (12500–3600 cm-1), physical, and biochemical measurements were performed individually on 100 litchi fruits of cv.Shahi cultivar harvested at different ripening stages. Relationships between spectral wavelengths and quality attributes were evaluated by application of chemometric techniques based on partial least squares (PLS) regression. The fruit set was divided into two groups: 60 fruits for calibration and 39 for validation. Good prediction performance was obtained for pH, soluble solids, and titratable acidity with correlation coefficients of 0.96, 0.91 and 0.94 respectively and root mean square errors of prediction of 0.009, 0.291ºBrix and 0.011% malic acid respectively. For the other quality traits such as vitamin C and color the prediction models were not satisfactorily accurate due to the higherror of calibration and prediction.
ABSTRACT
Objective:To establish a rapid analysis method for determining the content of ephedrine in Biyan sprays. Methods:The FT-NIR spectra of the samples were collected by near-infrared liquid transmission spectroscopy. Using the HPLC analysis values as the reference, a quantitative analysis model for ephedrine was established with partial least square ( PLS) , the first derivative and Nor-ris smooth was used in the spectra pretreatment, and 6 136. 38-5 364. 99 cm-1 and 7 038. 90-6 969. 48 cm-1 were selected as the fre-quency ranges. Results:R2 and RMSEC of the calibration set was 0. 992 6 and 1. 20, respectively. R2 and RMSEP of the vallidation set was 0. 993 5 and 1. 28, respectively. R2 and RMSEP of the cross validation set was 0. 986 9 and 1. 60, respectively. Conclusion:The method is rapid and non-desturctive, and can be applied in the rapid assessment and online examination of the quality of Biyan sprays.
ABSTRACT
OBJECTIVES: This study investigated the hypothesis that increasing light-curing time would leave the oxygen-inhibited layer (OIL) of the adhesive thinner, and in turn, result in lower shear bond strength (SBS) than those obtained by the routine curing procedures. METHODS: 120 human extracted posterior teeth were randomly divided into three groups for bonding with three adhesives: All Bond 2(R), One Step(R), and Adper Prompt(R). They were subsequently divided into four subgourps with different light-curing time (10, 20, 30 and 60 s). The assigned adhesives were applied on superficial occlusal dentin according to the manufacturer's instructions and cured with one of the four curing times. Composite resin cylinder, 2.35 mm in diameter, were built on the cured adhesive and light-cured for 40 s. SBS were measured after 24 h from the bonding using a universal testing machine (crosshead speed 1.0 mm/min). The relative thickness of the OIL and the degree of conversion (DC) were determined from the adhesive on a slide glass using FT-NIR in an absorbance mode. Data were analysed with One-way ANOVA and Duncan's multiple test (p 0.05), those of All Bond 2 decreased significantly (p 0.05). Although the DC of All-Bond 2 were statistically not different with increasing cure time (p > 0.05), those of One-Step and Adper Prompt showed an increasing trends with increasing cure time (p < 0.05). CONCLUSIONS: Increasing light-curing time did not affect on the relative thickness of the OIL of the adhesives, and in turn, on the SBS to dentin.
Subject(s)
Humans , Adhesives , Dentin , Glass , ToothABSTRACT
OBJECTIVES: This study investigated the hypothesis that increasing light-curing time would leave the oxygen-inhibited layer (OIL) of the adhesive thinner, and in turn, result in lower shear bond strength (SBS) than those obtained by the routine curing procedures. METHODS: 120 human extracted posterior teeth were randomly divided into three groups for bonding with three adhesives: All Bond 2(R), One Step(R), and Adper Prompt(R). They were subsequently divided into four subgourps with different light-curing time (10, 20, 30 and 60 s). The assigned adhesives were applied on superficial occlusal dentin according to the manufacturer's instructions and cured with one of the four curing times. Composite resin cylinder, 2.35 mm in diameter, were built on the cured adhesive and light-cured for 40 s. SBS were measured after 24 h from the bonding using a universal testing machine (crosshead speed 1.0 mm/min). The relative thickness of the OIL and the degree of conversion (DC) were determined from the adhesive on a slide glass using FT-NIR in an absorbance mode. Data were analysed with One-way ANOVA and Duncan's multiple test (p 0.05), those of All Bond 2 decreased significantly (p 0.05). Although the DC of All-Bond 2 were statistically not different with increasing cure time (p > 0.05), those of One-Step and Adper Prompt showed an increasing trends with increasing cure time (p < 0.05). CONCLUSIONS: Increasing light-curing time did not affect on the relative thickness of the OIL of the adhesives, and in turn, on the SBS to dentin.