In order to solve the problems of low accuracy and poor variety adaptability of the current measurement method of the permeability and coating property of sizing paste in textile industry, taking starch and polyvinyl ...In order to solve the problems of low accuracy and poor variety adaptability of the current measurement method of the permeability and coating property of sizing paste in textile industry, taking starch and polyvinyl alcohol(PVA) as the representatives of the most commonly used textile sizes, various concentrations of fluorescent molecules fluorescein isothiocyanate(FITC) were used to label starch and PVA to prepare fluorescein(F)-starch and F-PVA fluorescent sizes with different degrees of labeling(DLs) for the first time, respectively. Then the starch and PVA derivatives were employed to size pure cotton warp yarns. After preparing the sections of the sized yarns, the permeability and coating percentage of starch and PVA paste to the yarns were calculated by using a fluorescence microscope and the Photoshop software, respectively. The results demonstrate that F-starch and F-PVA with appropriate DL of 0.791% and 0.161%, respectively, exhibit good fluorescence property and similar sizing performance to the sizing performance of unlabeled starch and PVA. It is considered that fluorescence labeling of sizing agents with fluorescein units can provide an innovative way for the accurate determination of the permeability and coating property of sizing paste to warp yarns.展开更多
The mechanism of the nonlinear concentration dependence of the intestinal absorption of fluorescein isothiocyanate dextran 4,000 (FD-4) was studied using in situ rat intestinal loops and the in vitro Ussing-type chamb...The mechanism of the nonlinear concentration dependence of the intestinal absorption of fluorescein isothiocyanate dextran 4,000 (FD-4) was studied using in situ rat intestinal loops and the in vitro Ussing-type chamber method. The intestinal absorption rate constant of FD-4, as evaluated by the intestinal loop method, increased significantly in a nonlinear fashion as the FD-4 concentration increased up to 0.2 mM and tended to decrease at concentrations higher than 0.2 mM. The mucosal-to-serosal permeation of FD-4 across rat ileal sheets, as evaluated by the in vitro Ussing-type chamber method, also increased in a nonlinear fashion in the low concentration range (0.01 - 0.02 mM), before decreasing as the concentration increased further, whereas serosal-to-mucosal permeation decreased in a concentration-dependent manner. In addition, mucosal-to-serosal flux and serosal-to-mucosal flux were increased and reduced in the presence of the metabolic inhibitor 2, 4-dinitrophenol, respectively. These results suggest that FD-4 is predominantly secreted into the intestinal lumen by an efflux transport system.展开更多
To date, in vivo investigations of polysaccharide’s pharmacokinetics are significantly restricted by the difficulty in their detection. This study was conducted to establish the quantitative determination of Lycium b...To date, in vivo investigations of polysaccharide’s pharmacokinetics are significantly restricted by the difficulty in their detection. This study was conducted to establish the quantitative determination of Lycium barbarum polysaccharides(LBPs) based on fluorescein isothiocyanate(FITC) pre-labeling and to investigate their tissue distribution in rat. We obtained the calibration curves linear over the range of 0.0–25 μg/m L in rat tissue samples with correlation coefficients greater than 0.99. The inter-day and intra-day precisions(RSD, %) were within 15%, and the relative recovery ranged 95.2%–102.4%, with RSD range 1.48%–9.58%, indicating that this experiment was suitable for the determination of LBPs. The fluorescence intensity was measured after 24 h storage at room temperature, 3 times of freeze-cycle and cryopreservation at –20 ℃ for 15 day, these results indicated that the stability of the samples was good. LBP-FITC was mainly absorbed by the small intestine and stomach, and mainly excreted in the urine through the kidney;this distinct difference in the tissue distribution of LBPs could be attributed to the size of these LBPs in relation to the pore sizes of the vascular beds in the kidney and liver. Results showed in this study enable us to comprehensively understand the biological effects of LBPs following its oral ingestion.展开更多
基金National Natural Science Foundation of China(Nos.51573095 and 51873187)Project of Key Laboratory of Clean Dyeing and Finishing Technology of Zhejiang Province,China(No.QJRZ1902)+1 种基金Technological Research Project for Public Welfare of Zhejiang Province,China(No.LGG21E030005)Postdoctoral Research Program of Zhejiang Province in 2021,China。
文摘In order to solve the problems of low accuracy and poor variety adaptability of the current measurement method of the permeability and coating property of sizing paste in textile industry, taking starch and polyvinyl alcohol(PVA) as the representatives of the most commonly used textile sizes, various concentrations of fluorescent molecules fluorescein isothiocyanate(FITC) were used to label starch and PVA to prepare fluorescein(F)-starch and F-PVA fluorescent sizes with different degrees of labeling(DLs) for the first time, respectively. Then the starch and PVA derivatives were employed to size pure cotton warp yarns. After preparing the sections of the sized yarns, the permeability and coating percentage of starch and PVA paste to the yarns were calculated by using a fluorescence microscope and the Photoshop software, respectively. The results demonstrate that F-starch and F-PVA with appropriate DL of 0.791% and 0.161%, respectively, exhibit good fluorescence property and similar sizing performance to the sizing performance of unlabeled starch and PVA. It is considered that fluorescence labeling of sizing agents with fluorescein units can provide an innovative way for the accurate determination of the permeability and coating property of sizing paste to warp yarns.
文摘The mechanism of the nonlinear concentration dependence of the intestinal absorption of fluorescein isothiocyanate dextran 4,000 (FD-4) was studied using in situ rat intestinal loops and the in vitro Ussing-type chamber method. The intestinal absorption rate constant of FD-4, as evaluated by the intestinal loop method, increased significantly in a nonlinear fashion as the FD-4 concentration increased up to 0.2 mM and tended to decrease at concentrations higher than 0.2 mM. The mucosal-to-serosal permeation of FD-4 across rat ileal sheets, as evaluated by the in vitro Ussing-type chamber method, also increased in a nonlinear fashion in the low concentration range (0.01 - 0.02 mM), before decreasing as the concentration increased further, whereas serosal-to-mucosal permeation decreased in a concentration-dependent manner. In addition, mucosal-to-serosal flux and serosal-to-mucosal flux were increased and reduced in the presence of the metabolic inhibitor 2, 4-dinitrophenol, respectively. These results suggest that FD-4 is predominantly secreted into the intestinal lumen by an efflux transport system.
基金the support from the National Key Research and Development Program of China(No.2016YFD400604-02)the National Natural Science Foundation of China(No.82073551,82003457,81273069)+3 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX19_0121)the Scientific Research Foundation of Graduate School of Southeast University(No.YBPY1944)the Fundamental Research Funds for the Central Universities(No.2242020R10006)CNS Research Fund for DRI。
文摘To date, in vivo investigations of polysaccharide’s pharmacokinetics are significantly restricted by the difficulty in their detection. This study was conducted to establish the quantitative determination of Lycium barbarum polysaccharides(LBPs) based on fluorescein isothiocyanate(FITC) pre-labeling and to investigate their tissue distribution in rat. We obtained the calibration curves linear over the range of 0.0–25 μg/m L in rat tissue samples with correlation coefficients greater than 0.99. The inter-day and intra-day precisions(RSD, %) were within 15%, and the relative recovery ranged 95.2%–102.4%, with RSD range 1.48%–9.58%, indicating that this experiment was suitable for the determination of LBPs. The fluorescence intensity was measured after 24 h storage at room temperature, 3 times of freeze-cycle and cryopreservation at –20 ℃ for 15 day, these results indicated that the stability of the samples was good. LBP-FITC was mainly absorbed by the small intestine and stomach, and mainly excreted in the urine through the kidney;this distinct difference in the tissue distribution of LBPs could be attributed to the size of these LBPs in relation to the pore sizes of the vascular beds in the kidney and liver. Results showed in this study enable us to comprehensively understand the biological effects of LBPs following its oral ingestion.
