Plants and plant-based products are the bases of many modern pharmaceuticals that are current in use today for various diseases.The aim of the study was to investigate the biochemical constituents and high performance...Plants and plant-based products are the bases of many modern pharmaceuticals that are current in use today for various diseases.The aim of the study was to investigate the biochemical constituents and high performance thin layer chromatography（HPTLC） finger printing of the ethanolic extract of Evolvulus alsinoides.Phytochemical screening was done by standard procedures and HPTLC method was also established to analyze alkaloids,flavonoids and phenolic compounds from the ethanolic extract of Evolvulus alsinoides.Preliminary phytochemical screening showed that ethanol extracted more secondary metabolites than other solvents.HPTLC fingerprinting analysis showed the presence of various alkaloids,flavonoids and phenols（quercetin） in the ethanolic extract.It can be concluded that Evolvulus alsinoides may serve as a source of potent antioxidants that may be used in the prevention of various diseases such as cancer,diabetes and cardiovascular diseases due to the presence of phenolic compounds.HPTLC finger print of Evolvulus alsinoides may be useful in the differentiation of the species from adulterants and act as a biochemical marker for this medicinally important plant in the pharmaceutical industry and plant systematic studies.展开更多
Dear Editor： Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia （Saxifragaceae） is an evergreen perennial herb widely distribut...Dear Editor： Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia （Saxifragaceae） is an evergreen perennial herb widely distributed in Central and East Asia with about 30 species reported worldwide. It grows at a range of altitudes from the Khasia hills at 400 feet to the temperate Himalayas from Kashmir to Bhutan at 7,000-10,000 feet. Its distribution over a wide range of altitudinal zones makes it a good candidate for studying variations in its metabolic profiles under different climatic conditions. Bergenin （C-glycoside of 4-O-methyl gallic acid） has been identified as a potent active secondary metabolite in Bergenia and other therapeutically active constituents including, among others, gallic acid （3,4,5 trihydroxybenzoic acid）, （＋） catechin, and gallicin （Fig. 1）.展开更多
Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transm...Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.展开更多
We present a systematic analysis of the exciton-recombination zone within all-quantum-dot （QD） multilayer films using sensing QD layers in QD-based light-emitting diodes （QLEDs）, and demonstrate the a11-QD multila...We present a systematic analysis of the exciton-recombination zone within all-quantum-dot （QD） multilayer films using sensing QD layers in QD-based light-emitting diodes （QLEDs）, and demonstrate the a11-QD multilayer films with different sequences of layers prepared by inserting a sensing blue QD layer denoted as B at various positions within four red QD multilayers denoted as R. We also use different hole transporting layers （PVK, CBP as well as poly-TPD） to prevent the formation of leakage current and to improve the luminance. The results show that the total EL emission is mostly at the fourth （60%） and fifth （40%） QD monolayers, adjacent to ITO. This presents both decreasing current density and increasing brightness with different hole transporting layers, thus resulting in more efficient performance.展开更多
The Cu2ZnSnS4 （CZTS）-based solar cell is numerically simulated by a one-dimensional solar cell simulation soft- ware analysis of microelectronic and photonic structures （AMPS-1D）. The device structure used in the ...The Cu2ZnSnS4 （CZTS）-based solar cell is numerically simulated by a one-dimensional solar cell simulation soft- ware analysis of microelectronic and photonic structures （AMPS-1D）. The device structure used in the simulation is Al/ZnO：Al/nZn（O,S）/pCZTS/Mo. The primary motivation of this simulation work is to optimize the composition in the ZnO1-xSx buffer layer, which would yield higher conversion efficiency. By varying S/（S＋O） ratio x, the conduction band offset （CBO） at CZTS/Zn（O,S） interface can range from -0.23 eV to 1.06eV if the full range of the ratio is considered. The optimal CBO of 0.23eV can be achieved when the ZnO1-xSx buffer has an S/（S＋O） ratio of 0.6. The solar cell efficiency first increases with increasing sulfur content and then decreases abruptly for x〉 0.6, which reaches the highest value of 17.55% by our proposed optimal sulfur content x= 0.6. Our results provide guidance in dealing with the ZnO1-xSx buffer layer deposition for high efficiency CZTS solar cells.展开更多
From different reports, it （AZO） and indium-doped including usage areas. We nanocrystalline films with is realized that there is a need to consider all sides of aluminum-doped zinc oxide zinc oxide （IZO） thin film...From different reports, it （AZO） and indium-doped including usage areas. We nanocrystalline films with is realized that there is a need to consider all sides of aluminum-doped zinc oxide zinc oxide （IZO） thin films with their optical, luminescence and surface properties establish an assessment to carry out further information to summarize AZO and IZO impact of the layer number.展开更多
Influence of the layer parameters on the performances of the CdTe solar cells is analyzed by SCAPS-1 D. The Zn O: Al film shows a high efficiency than SnO_2:F. Moreover, the thinner window layer and lower defect densi...Influence of the layer parameters on the performances of the CdTe solar cells is analyzed by SCAPS-1 D. The Zn O: Al film shows a high efficiency than SnO_2:F. Moreover, the thinner window layer and lower defect density of Cd S films are the factor in the enhancement of the short-circuit current density. As well, to increase the open-circuit voltage, the responsible factors are low defect density of the absorbing layer CdTe and high metal work function. For the low cost of cell production, ultrathin film CdTe cells are used with a back surface field(BSF) between CdTe and back contact, such as PbTe. Further, the simulation results show that the conversion efficiency of 19.28% can be obtained for the cell with 1-μm-thick CdTe, 0.1-μm-thick PbTe and 30-nm-thick CdS.展开更多
Given severe health-hazardous effects of aflatoxin B1(AFB1) widely occurring in cereal grains and animal feeds,it is highly urgent to develop analytical methods for its rapid screening.In this work,we proposed a simpl...Given severe health-hazardous effects of aflatoxin B1(AFB1) widely occurring in cereal grains and animal feeds,it is highly urgent to develop analytical methods for its rapid screening.In this work,we proposed a simple and high-throughput method for the determination of AFB1 in millet and buckwheat samples using high performance thin layer chromatography(HPTLC) linked to fluorescence densitometry.The first step was to optimize the solid-liquid extraction for the crude clean-up of the samples.The QuEChERS(Quick,Easy,Cheap,Effective,Robust and Safe) extraction strategy was used and different solvent systems for their extraction efficiency of AFB1 from the samples were evaluated.Then,trichloromethane:ethyl acetate(7:3,V/V) was used as the mobile phase to realize the separation of the targeted compound from background noises on silica gel plates.Quantification was readily performed with densitometry in fluorescence mode.In order to fix the optimal excitation wavelength,spectra scanning ranging 250-400 nm was carried out,revealing that 364 nm light gave the highest signal.With the optimized optical system,high sensitivity to AFB1 was achieved,with a limit of detection(LOD) at 3 μg/kg.Apart from that,good linearity(0.999) was obtained within the range of 1-80 ng/band of AFB 1.To assess the analysis accuracy,2 levels of AFB 1(50 and100 μg/kg) were spiked into real grain samples.The obtained results showed that the recovery rates were within the range of 81.6%-114.0%.The proof-of-concept results of this work evidenced that HPTLC is a promising analytical tool for the screening of mycotoxin in difficult samples.展开更多
Objective 3-Bromobenzanthrone (3-BBA), an anthraquinone intermediate dye, is extensively used in textile industry. Since, our prior studies have shown that 3-BBA caused significant depletion of ascorbic acid (AsA) le...Objective 3-Bromobenzanthrone (3-BBA), an anthraquinone intermediate dye, is extensively used in textile industry. Since, our prior studies have shown that 3-BBA caused significant depletion of ascorbic acid (AsA) levels, the effect of exogenous supplementation of AsA on the urinary elimination of 3-BBA metabolites was investigated. Method Guinea pigs were treated with single oral dose of 3-BBA (50 mg/kg b. wt.) in groundnut oil while another group was treated with single oral dose of 3-BBA (50 mg/kg b. wt.) along with 3 day prior and post oral supplementation of AsA. Control groups were either treated with groundnut oil or AsA alone. Urine from individual animals was collected, extracted and analysed on HPTLC. Results The highest elimination of 3-BBA (75 mg) was found to be in 0-24 h urine fraction which decreased to 18 mg and 5 mg in the two subsequent 24 hourly fractions of urine. Exogenous supplementation of AsA increased the total urinary elimination of 3-BBA by almost 77%. A total of 10 fluorescent metabolites excluding the parent compound were eliminated in the urine of guinea pigs treated with 3-BBA. Densitometric scanning of chromatogram showed different peaks at Rf 0.18, 0.22, 0.27, 0.34, 0.40, 0.48, 0.56, 0.66, 0.72, 0.80, and 0.95 which were eliminated and marked as urinary metabolite 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 respectively. AsA not only significantly enhanced the elimination of 3-BBA metabolites but also modified the pattern of metabolites drastically in 0-6 h, 6-24 h and 24-48 h urine fractions. Conclusion These results indicate that AsA may be useful in protecting the toxicity of 3-BBA by fascilitating the urinary metabolite(s) excretion of 3-BBA.展开更多
A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate,a synthetic inorganic ion exchanger as adsorbent in thi...A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate,a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography(TLC).A mixture of methanol and 0.1 mol/L formic acid(3∶7,v/v)was employed as the mobile phase.The development time was 32 min.The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength(λ)of 410 nm.The isoproterenol recovery in this procedure was 98.9%.The linear correlation coefficient was greater than 0.987 1 and the relative standard deviation(RSD)was less than 0.94.The limit of detection(LOD)and limit of quantification(LOQ)were 7.7×10-7mol/L and 3.85×10-6mol/L,respectively.This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.展开更多
Objective:To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L.(M.spicata),Mentha pulegium L.and Mentha rotundifolia(L.)Huds by high performance thin layer chromatography(HPTL...Objective:To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L.(M.spicata),Mentha pulegium L.and Mentha rotundifolia(L.)Huds by high performance thin layer chromatography(HPTLC)-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation.Methods:The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform:acetone:formic acid(75:16.5:8.5,v/v)as the mobile phase.Rosmarinic acid was determined in UV at 365 nm and fluorescence at λ_(exc)325 nm with a 550 nm filter,respectively.The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method.Results:Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1000 ng/spot.M.spicata was found to contain significantly higher concentrations of rosmarinic acid.The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision(total precision for Mentha spp extracts,5.1%and 5.8%for UV and fluorescence detection,respectively).The HPTLC data,allied to assays of linoleic acid peroxidation prevention,suggested the potential of M.spicata(52%Trolox®equivalents)as a natural source for inhibitors of lipid peroxidation.Conclusions:Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.展开更多
Bi_(2)O_(2)Se is highly competitive as a candidate of next-generation high-performance semiconductors.Though dubbed as semiconductor,Bi_(2)O_(2)Se films exhibited high conductance,i.e.,metallic behavior,due to spontan...Bi_(2)O_(2)Se is highly competitive as a candidate of next-generation high-performance semiconductors.Though dubbed as semiconductor,Bi_(2)O_(2)Se films exhibited high conductance,i.e.,metallic behavior,due to spontaneously ionized defects.Semiconducting/insulating films are of practical importance in broad applications based on low-power,high-performance electronics,the existence of which lacks firm evidence.Here,we synthesized highly insulating films in a controlled way,which exhibit semiconducting behavior with channel resistance up to 1 TΩ.The electron chemical potential lies within the band gap,in some cases,even below the charge neutrality level,signifying the trace of hole-type semiconducting.The performance of insulating devices remains high,comparable to high-quality devices previously.Especially,the threshold voltage(Vth)is positive,contrary to common negative values reported.Calculations indicate that our synthesis conditions suppress electron donors(Se vacancies(VSe))and promote the formation of compensating acceptors(Bi vacancies(VBi)),leading to insulating behaviors.Our work offers insights into electron dynamics of Bi_(2)O_(2)Se,moves one step further towards p-type transistors and provides a valuable playground for engineering ferroelectricity in high-performance semiconductors.展开更多
Aflatoxin B_(1)(AFB_(1))and deoxynivalenol(DON)are among the most frequently detected mycotoxin in cereals,po sing great challenge to human health.This work proposed a co st-efficient and robust planar chromatography ...Aflatoxin B_(1)(AFB_(1))and deoxynivalenol(DON)are among the most frequently detected mycotoxin in cereals,po sing great challenge to human health.This work proposed a co st-efficient and robust planar chromatography method for the rapid screening AFB_(1) in millet and buckwheat,as well as DON in wheat,corn,barley,and oats,achieving detection of the two common fungal toxins in cereals.First,the sample preparation was realized by a simple extraction with 10 mL of acetonitrile,both containing 4 g of anhydrous MgSO_(4),1 g of NaCl,and25 mg of primary secondary amine adsorbent.After high throughput chromatography,which resulted in the separation of the targeted compound from background noise and derivatization with 10%ethanol solution of AlCl_(3)(only for the visualization of DON).The separation results were recorded using a smartphone in a dark chamber equipped with a 366 nm ultraviolet source.To simplify the analysis,the quantification of the graphical outcome was carried out using the open-source software ImageJ,based on quantifying digitalized pixel values.It was demonstrated that the detection sensitivity(AFB_(1):limit of detection(LOD)=14.2μg/kg,DON:LOD=64.3μg/kg)was adequate to meet the strict maximum residue limit stipulated for both targeted compounds,while calibration curves gave good linearity(AFB_(1):correlation coefficient(R^(2))=0.967 within 1-80 ng/band,DON:R^(2)=0.998 within 50-800 ng/band).Then the method accuracy and precision were evaluated by spikingrecovery experiments,showing that the recovery rates of AFB_(1) was within 76.9%-113.6%and those DON within 91.0%-116.5%,with relative standard deviations of less than 4.9%and 5.8%for AFB_(1) and DON,respectively.The conceptual validation of this study demonstrates that the high performance thin layer chromatography(HPTLC)-image quantification method has effectively addressed the limitation of HPTLC imaging results being confined to preliminary screening without the capability of precise quantification,thereby bridging the gap between imaging and quantification.This method exhibits promising analytical tool characteristics and is suitable for screening mycotoxins in cereal samples.展开更多
文摘Plants and plant-based products are the bases of many modern pharmaceuticals that are current in use today for various diseases.The aim of the study was to investigate the biochemical constituents and high performance thin layer chromatography（HPTLC） finger printing of the ethanolic extract of Evolvulus alsinoides.Phytochemical screening was done by standard procedures and HPTLC method was also established to analyze alkaloids,flavonoids and phenolic compounds from the ethanolic extract of Evolvulus alsinoides.Preliminary phytochemical screening showed that ethanol extracted more secondary metabolites than other solvents.HPTLC fingerprinting analysis showed the presence of various alkaloids,flavonoids and phenols（quercetin） in the ethanolic extract.It can be concluded that Evolvulus alsinoides may serve as a source of potent antioxidants that may be used in the prevention of various diseases such as cancer,diabetes and cardiovascular diseases due to the presence of phenolic compounds.HPTLC finger print of Evolvulus alsinoides may be useful in the differentiation of the species from adulterants and act as a biochemical marker for this medicinally important plant in the pharmaceutical industry and plant systematic studies.
文摘Dear Editor： Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia （Saxifragaceae） is an evergreen perennial herb widely distributed in Central and East Asia with about 30 species reported worldwide. It grows at a range of altitudes from the Khasia hills at 400 feet to the temperate Himalayas from Kashmir to Bhutan at 7,000-10,000 feet. Its distribution over a wide range of altitudinal zones makes it a good candidate for studying variations in its metabolic profiles under different climatic conditions. Bergenin （C-glycoside of 4-O-methyl gallic acid） has been identified as a potent active secondary metabolite in Bergenia and other therapeutically active constituents including, among others, gallic acid （3,4,5 trihydroxybenzoic acid）, （＋） catechin, and gallicin （Fig. 1）.
基金Project supported by the National Natural Science Foundation of China(Grant No.61106060)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.Y2YF028001)the National High Technology Research and Development Program of China(Grant No.2012AA052401)
文摘Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.
基金Supported by the National High Technology Research and Development Program of China under Grant No 2013AA032205the National Natural Science Foundation of China under Grant Nos 11474018,51272022 and 61575019+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant Nos 20120009130005 and 20130009130001the Technological Development Contract under Grant No HETONG-150188-04E008
文摘We present a systematic analysis of the exciton-recombination zone within all-quantum-dot （QD） multilayer films using sensing QD layers in QD-based light-emitting diodes （QLEDs）, and demonstrate the a11-QD multilayer films with different sequences of layers prepared by inserting a sensing blue QD layer denoted as B at various positions within four red QD multilayers denoted as R. We also use different hole transporting layers （PVK, CBP as well as poly-TPD） to prevent the formation of leakage current and to improve the luminance. The results show that the total EL emission is mostly at the fourth （60%） and fifth （40%） QD monolayers, adjacent to ITO. This presents both decreasing current density and increasing brightness with different hole transporting layers, thus resulting in more efficient performance.
基金Supported by the Guiding Project of Strategic Emerging Industries of Fujian Provincial Department of Science and Technology under Grant No 2015H0010the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure of Shanghai Institute of Ceramics of Chinese Academy of Sciences under Grant No SKL201404SICthe Natural Science Foundation of Fujian Province under Grant No 2016J01751
文摘The Cu2ZnSnS4 （CZTS）-based solar cell is numerically simulated by a one-dimensional solar cell simulation soft- ware analysis of microelectronic and photonic structures （AMPS-1D）. The device structure used in the simulation is Al/ZnO：Al/nZn（O,S）/pCZTS/Mo. The primary motivation of this simulation work is to optimize the composition in the ZnO1-xSx buffer layer, which would yield higher conversion efficiency. By varying S/（S＋O） ratio x, the conduction band offset （CBO） at CZTS/Zn（O,S） interface can range from -0.23 eV to 1.06eV if the full range of the ratio is considered. The optimal CBO of 0.23eV can be achieved when the ZnO1-xSx buffer has an S/（S＋O） ratio of 0.6. The solar cell efficiency first increases with increasing sulfur content and then decreases abruptly for x〉 0.6, which reaches the highest value of 17.55% by our proposed optimal sulfur content x= 0.6. Our results provide guidance in dealing with the ZnO1-xSx buffer layer deposition for high efficiency CZTS solar cells.
文摘From different reports, it （AZO） and indium-doped including usage areas. We nanocrystalline films with is realized that there is a need to consider all sides of aluminum-doped zinc oxide zinc oxide （IZO） thin films with their optical, luminescence and surface properties establish an assessment to carry out further information to summarize AZO and IZO impact of the layer number.
文摘Influence of the layer parameters on the performances of the CdTe solar cells is analyzed by SCAPS-1 D. The Zn O: Al film shows a high efficiency than SnO_2:F. Moreover, the thinner window layer and lower defect density of Cd S films are the factor in the enhancement of the short-circuit current density. As well, to increase the open-circuit voltage, the responsible factors are low defect density of the absorbing layer CdTe and high metal work function. For the low cost of cell production, ultrathin film CdTe cells are used with a back surface field(BSF) between CdTe and back contact, such as PbTe. Further, the simulation results show that the conversion efficiency of 19.28% can be obtained for the cell with 1-μm-thick CdTe, 0.1-μm-thick PbTe and 30-nm-thick CdS.
基金supported by National Key Research and Development Program of China (2021YFF0601902)Shanxi Scholarship Council of China (2021-068)+1 种基金Opening Project of Key Laboratory of Detection for Mycotoxins, Ministry of Agriculture and Rural Affairs China (SWDSJC2021001)Shanxi Agricultural University High-Level Talent Project (2021XG013)。
文摘Given severe health-hazardous effects of aflatoxin B1(AFB1) widely occurring in cereal grains and animal feeds,it is highly urgent to develop analytical methods for its rapid screening.In this work,we proposed a simple and high-throughput method for the determination of AFB1 in millet and buckwheat samples using high performance thin layer chromatography(HPTLC) linked to fluorescence densitometry.The first step was to optimize the solid-liquid extraction for the crude clean-up of the samples.The QuEChERS(Quick,Easy,Cheap,Effective,Robust and Safe) extraction strategy was used and different solvent systems for their extraction efficiency of AFB1 from the samples were evaluated.Then,trichloromethane:ethyl acetate(7:3,V/V) was used as the mobile phase to realize the separation of the targeted compound from background noises on silica gel plates.Quantification was readily performed with densitometry in fluorescence mode.In order to fix the optimal excitation wavelength,spectra scanning ranging 250-400 nm was carried out,revealing that 364 nm light gave the highest signal.With the optimized optical system,high sensitivity to AFB1 was achieved,with a limit of detection(LOD) at 3 μg/kg.Apart from that,good linearity(0.999) was obtained within the range of 1-80 ng/band of AFB 1.To assess the analysis accuracy,2 levels of AFB 1(50 and100 μg/kg) were spiked into real grain samples.The obtained results showed that the recovery rates were within the range of 81.6%-114.0%.The proof-of-concept results of this work evidenced that HPTLC is a promising analytical tool for the screening of mycotoxin in difficult samples.
文摘Objective 3-Bromobenzanthrone (3-BBA), an anthraquinone intermediate dye, is extensively used in textile industry. Since, our prior studies have shown that 3-BBA caused significant depletion of ascorbic acid (AsA) levels, the effect of exogenous supplementation of AsA on the urinary elimination of 3-BBA metabolites was investigated. Method Guinea pigs were treated with single oral dose of 3-BBA (50 mg/kg b. wt.) in groundnut oil while another group was treated with single oral dose of 3-BBA (50 mg/kg b. wt.) along with 3 day prior and post oral supplementation of AsA. Control groups were either treated with groundnut oil or AsA alone. Urine from individual animals was collected, extracted and analysed on HPTLC. Results The highest elimination of 3-BBA (75 mg) was found to be in 0-24 h urine fraction which decreased to 18 mg and 5 mg in the two subsequent 24 hourly fractions of urine. Exogenous supplementation of AsA increased the total urinary elimination of 3-BBA by almost 77%. A total of 10 fluorescent metabolites excluding the parent compound were eliminated in the urine of guinea pigs treated with 3-BBA. Densitometric scanning of chromatogram showed different peaks at Rf 0.18, 0.22, 0.27, 0.34, 0.40, 0.48, 0.56, 0.66, 0.72, 0.80, and 0.95 which were eliminated and marked as urinary metabolite 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 respectively. AsA not only significantly enhanced the elimination of 3-BBA metabolites but also modified the pattern of metabolites drastically in 0-6 h, 6-24 h and 24-48 h urine fractions. Conclusion These results indicate that AsA may be useful in protecting the toxicity of 3-BBA by fascilitating the urinary metabolite(s) excretion of 3-BBA.
基金Financial assistance was provided by Kharazmi University,Research Council
文摘A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate,a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography(TLC).A mixture of methanol and 0.1 mol/L formic acid(3∶7,v/v)was employed as the mobile phase.The development time was 32 min.The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength(λ)of 410 nm.The isoproterenol recovery in this procedure was 98.9%.The linear correlation coefficient was greater than 0.987 1 and the relative standard deviation(RSD)was less than 0.94.The limit of detection(LOD)and limit of quantification(LOQ)were 7.7×10-7mol/L and 3.85×10-6mol/L,respectively.This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.
文摘Objective:To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L.(M.spicata),Mentha pulegium L.and Mentha rotundifolia(L.)Huds by high performance thin layer chromatography(HPTLC)-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation.Methods:The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform:acetone:formic acid(75:16.5:8.5,v/v)as the mobile phase.Rosmarinic acid was determined in UV at 365 nm and fluorescence at λ_(exc)325 nm with a 550 nm filter,respectively.The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method.Results:Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1000 ng/spot.M.spicata was found to contain significantly higher concentrations of rosmarinic acid.The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision(total precision for Mentha spp extracts,5.1%and 5.8%for UV and fluorescence detection,respectively).The HPTLC data,allied to assays of linoleic acid peroxidation prevention,suggested the potential of M.spicata(52%Trolox®equivalents)as a natural source for inhibitors of lipid peroxidation.Conclusions:Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.
基金supported by the National Natural Science Foundation of China(Nos.11904294 and 62004172)the foundation of Westlake Multidisciplinary Research Initiative Center(MRIC,Nos.MRIC20200402 and 20200101).
文摘Bi_(2)O_(2)Se is highly competitive as a candidate of next-generation high-performance semiconductors.Though dubbed as semiconductor,Bi_(2)O_(2)Se films exhibited high conductance,i.e.,metallic behavior,due to spontaneously ionized defects.Semiconducting/insulating films are of practical importance in broad applications based on low-power,high-performance electronics,the existence of which lacks firm evidence.Here,we synthesized highly insulating films in a controlled way,which exhibit semiconducting behavior with channel resistance up to 1 TΩ.The electron chemical potential lies within the band gap,in some cases,even below the charge neutrality level,signifying the trace of hole-type semiconducting.The performance of insulating devices remains high,comparable to high-quality devices previously.Especially,the threshold voltage(Vth)is positive,contrary to common negative values reported.Calculations indicate that our synthesis conditions suppress electron donors(Se vacancies(VSe))and promote the formation of compensating acceptors(Bi vacancies(VBi)),leading to insulating behaviors.Our work offers insights into electron dynamics of Bi_(2)O_(2)Se,moves one step further towards p-type transistors and provides a valuable playground for engineering ferroelectricity in high-performance semiconductors.
基金financially supported by the Opening Project of Key Laboratory of Detection for My cotoxins,Ministry of Agriculture and Rural Affairs,China(SWDSJC2021001)。
文摘Aflatoxin B_(1)(AFB_(1))and deoxynivalenol(DON)are among the most frequently detected mycotoxin in cereals,po sing great challenge to human health.This work proposed a co st-efficient and robust planar chromatography method for the rapid screening AFB_(1) in millet and buckwheat,as well as DON in wheat,corn,barley,and oats,achieving detection of the two common fungal toxins in cereals.First,the sample preparation was realized by a simple extraction with 10 mL of acetonitrile,both containing 4 g of anhydrous MgSO_(4),1 g of NaCl,and25 mg of primary secondary amine adsorbent.After high throughput chromatography,which resulted in the separation of the targeted compound from background noise and derivatization with 10%ethanol solution of AlCl_(3)(only for the visualization of DON).The separation results were recorded using a smartphone in a dark chamber equipped with a 366 nm ultraviolet source.To simplify the analysis,the quantification of the graphical outcome was carried out using the open-source software ImageJ,based on quantifying digitalized pixel values.It was demonstrated that the detection sensitivity(AFB_(1):limit of detection(LOD)=14.2μg/kg,DON:LOD=64.3μg/kg)was adequate to meet the strict maximum residue limit stipulated for both targeted compounds,while calibration curves gave good linearity(AFB_(1):correlation coefficient(R^(2))=0.967 within 1-80 ng/band,DON:R^(2)=0.998 within 50-800 ng/band).Then the method accuracy and precision were evaluated by spikingrecovery experiments,showing that the recovery rates of AFB_(1) was within 76.9%-113.6%and those DON within 91.0%-116.5%,with relative standard deviations of less than 4.9%and 5.8%for AFB_(1) and DON,respectively.The conceptual validation of this study demonstrates that the high performance thin layer chromatography(HPTLC)-image quantification method has effectively addressed the limitation of HPTLC imaging results being confined to preliminary screening without the capability of precise quantification,thereby bridging the gap between imaging and quantification.This method exhibits promising analytical tool characteristics and is suitable for screening mycotoxins in cereal samples.
