The aim of this study is to evaluate the ability of powder X-ray diffraction(PXRD)differential scanning calo-rimetry(DSC)and near infrared(NIR)spectroscopy to quantify two polymorphic forms(B,H)of nateglinide in binar...The aim of this study is to evaluate the ability of powder X-ray diffraction(PXRD)differential scanning calo-rimetry(DSC)and near infrared(NIR)spectroscopy to quantify two polymorphic forms(B,H)of nateglinide in binary powder mixtures.For this purpose,univariate and multivariate method are developed.The results show that PXRD(with PLS regression)provides a reliable determination of nateglinide samples(predicted accuracy of 89.1%),which is the best choice for quantification of nateglinide polymorphic mixtures in practice,while NIR spectroscopy is the least accurate(predicted accuracy of 79.6%)mainly due to the effect of sample inhomogeneity.Though a good linear relation and a high predicted accuracy(93.4%)for DSC are successfully obtained,it could not be a practical way for low-content quanti-fication in nateglinide polymorphic mixtures.展开更多
Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsilliti...Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsillitis,diabetes,pneumonia.The current study was designed to combine molecular networking(MN)with diagnostic ions for rapid identification ofΔ^(7,9(11))stigmastane-type saponins which were theα-glucosidase inhibitory active substances in V.amygdalina.First,theα-glucosidase inhibitory activities of fiveΔ^(7,9(11))stigmastane-type steroid saponins that were previously isolated were screened,which indicated that theΔ^(7,9(11))stigmastane-type steroid saponin was one of the active constituents responsible for ameliorating diabetes.Furthermore,a strategy was proposed to identify stigmastane-type steroid saponins and verify the plausibility of derived fragmentation pathways by applying MN,MolNetEnhancer and unsupervised substructure annotation(MS2LDA).Based on this strategy,other sevenΔ^(7,9(11))stigmastane-type steroid saponins were identified from this plant.Our research provide scientific evidence for the antidiabetic potential of the steroid saponin-rich extract of V.amygdalina leaf.展开更多
In recent decades,the properties and behaviors of nanofluidic devices have been widely explored in varied subjects such as engineering,physics,chemistry,and biology.Among the rich properties of nanofluidics,ionic curr...In recent decades,the properties and behaviors of nanofluidic devices have been widely explored in varied subjects such as engineering,physics,chemistry,and biology.Among the rich properties of nanofluidics,ionic current rectification(ICR) is a unique phenomenon arising from asymmetric nanofluidic devices with electric double layer(EDL) overlapped.The ICR property is especially useful in applications including energy conversion,mass separation,sea water purification and bioanalysis.In this review,the ICR property in nanofluidics as well as the underlying mechanism is demonstrated.The influencing factors concerning to the ICR property are systematically summarized.The asymmetric geometry as well as the charge distribution is in charge of the ICR behavior occurring in nanofluidic devices.This review is aimed at readers who are interested in the fundamentals of mass transport in nanofluidics in general,as well as those who are willing to apply nanofluidics in various research fields.展开更多
基金Supported by Jiangsu Large Scientific Instruments Shared Services Platform Foundation(BZ201403)
文摘The aim of this study is to evaluate the ability of powder X-ray diffraction(PXRD)differential scanning calo-rimetry(DSC)and near infrared(NIR)spectroscopy to quantify two polymorphic forms(B,H)of nateglinide in binary powder mixtures.For this purpose,univariate and multivariate method are developed.The results show that PXRD(with PLS regression)provides a reliable determination of nateglinide samples(predicted accuracy of 89.1%),which is the best choice for quantification of nateglinide polymorphic mixtures in practice,while NIR spectroscopy is the least accurate(predicted accuracy of 79.6%)mainly due to the effect of sample inhomogeneity.Though a good linear relation and a high predicted accuracy(93.4%)for DSC are successfully obtained,it could not be a practical way for low-content quanti-fication in nateglinide polymorphic mixtures.
基金supported by the National Natural Science Foundation of China(No.81573550)。
文摘Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsillitis,diabetes,pneumonia.The current study was designed to combine molecular networking(MN)with diagnostic ions for rapid identification ofΔ^(7,9(11))stigmastane-type saponins which were theα-glucosidase inhibitory active substances in V.amygdalina.First,theα-glucosidase inhibitory activities of fiveΔ^(7,9(11))stigmastane-type steroid saponins that were previously isolated were screened,which indicated that theΔ^(7,9(11))stigmastane-type steroid saponin was one of the active constituents responsible for ameliorating diabetes.Furthermore,a strategy was proposed to identify stigmastane-type steroid saponins and verify the plausibility of derived fragmentation pathways by applying MN,MolNetEnhancer and unsupervised substructure annotation(MS2LDA).Based on this strategy,other sevenΔ^(7,9(11))stigmastane-type steroid saponins were identified from this plant.Our research provide scientific evidence for the antidiabetic potential of the steroid saponin-rich extract of V.amygdalina leaf.
基金supported by the National Natural Science Foundation of China(Nos.21874155,21575163)the Natural Science Foundation of Jiangsu Province(No.BK20191316)+2 种基金the Double First-Class University Project(No.CPU2018GY25)the State Key Laboratory of Analytical Chemistry for Life Science(No.SKLACLS1919)the Qing-Lan Project ofjiangsu Province(2019)。
文摘In recent decades,the properties and behaviors of nanofluidic devices have been widely explored in varied subjects such as engineering,physics,chemistry,and biology.Among the rich properties of nanofluidics,ionic current rectification(ICR) is a unique phenomenon arising from asymmetric nanofluidic devices with electric double layer(EDL) overlapped.The ICR property is especially useful in applications including energy conversion,mass separation,sea water purification and bioanalysis.In this review,the ICR property in nanofluidics as well as the underlying mechanism is demonstrated.The influencing factors concerning to the ICR property are systematically summarized.The asymmetric geometry as well as the charge distribution is in charge of the ICR behavior occurring in nanofluidic devices.This review is aimed at readers who are interested in the fundamentals of mass transport in nanofluidics in general,as well as those who are willing to apply nanofluidics in various research fields.
