Infrared(IR)spectroscopy,a technique within the realm of molecular vibrational spectroscopy,furnishes distinctive chemical signatures pivotal for both structural analysis and compound identification.A notable challeng...Infrared(IR)spectroscopy,a technique within the realm of molecular vibrational spectroscopy,furnishes distinctive chemical signatures pivotal for both structural analysis and compound identification.A notable challenge emerges from the misalignment between the mid-IR light wavelength range and molecular dimensions,culminating in a constrained absorption cross-section and diminished vibrational absorption coefficients(Supplementary data).展开更多
Huang-Lian-Jie-Du-Decoction （HLJDD） has been widely used for the treatment of Alzheimer＇s disease （AD） in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not cle...Huang-Lian-Jie-Du-Decoction （HLJDD） has been widely used for the treatment of Alzheimer＇s disease （AD） in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not clearly clarified yet. In present study, the water extract of HLJDD and subsequent three polarity fractions divided by different reagents were investigated. A total of 17 chromatographic peaks were confirmed by comparison with standards and their UV, MS spectra. Among them, 11 major compounds were determined by HPLC-DAD method with good linear regression relationship （r2, 0.9994-0.9999）, precisions （inter-day precision RSD, 0.79%-1.07%; intra-day precision RSD, 1.59%-2.10%）, repeatability （RSD, 1.66%-3.67%）, stability （RSD, 1.26%-4.77%） and recovery （95.24%-105.41%, RSD, 0.29%-2.69%）. Furthermore, PC12 cells and primary neurons cells were used for the neuroprotective effective assessment of aforementioned four samples from HLJDD. 3＂he total aqueous extract and n-butanol extract of HLJDD presented more significant effects than the other two parts. According to their quality and quantity determination results, iridoids and alkaloids have a positive correlation with the neuroprotective effectiveness of HLJDD.展开更多
A combined method of high performance liquid chromatograph-elecrtrospray-ionization mass spectrometer（HPLC-ESI-MS/MS） coupled with a photodiode array detector（HPLC-DAD） and principal component analysis（PCA） was ...A combined method of high performance liquid chromatograph-elecrtrospray-ionization mass spectrometer（HPLC-ESI-MS/MS） coupled with a photodiode array detector（HPLC-DAD） and principal component analysis（PCA） was applied to the qualitative and quantitative analyses of alkaloids in Cortex Phellodendri（CP） samples, and to the differentiation of two species of CP, Cortex Phellodendri Chinensis（CPC） and Cortex Phellodendri Amurensis（CPA）. Twenty-two peaks appeared in the HPLC-MS base peak chromatogram of CP detected by the HPLC-ESI-MS/MS analysis, and the alkaloids were identified according to the MSn data, the known MS fragmentation rules and the literature data. Five alkaloids including berberine, palmatine, jatrorrhizine, phellodendrine and magnoflorine were simultaneously determinated by the HPLC-DAD. Berberine was the primary component in all CP samples, and the contents of berberine and palmatine were exploited to be two critical parameters for effective discrimination between the two species of CP. The average content of berberine in CPC（58.75 mg/g） was higher than that in CPA（9.16 mg/g）, while the content of palmatine was less, only 0.25 mg/g in CPC and 4.19 mg/g in CPA. With the use of PCA, samples datasets were separated successfully into two different clusters corresponding to the two species, and berberine, pahnatine, phellodendrine and magnoflorine contribute most to the above mentioned calssifying . The proposed method oroved to be a useful tool in the aualitv control of Chinese herbal medicines.展开更多
Objective To explore the major compound in Polygonati Rhizoma(Huang Jing,黄精)for quality control.Methods The major compound was isolated and analyzed by liquid chromatography-mass spectrometry(LC-MS),and subsequently...Objective To explore the major compound in Polygonati Rhizoma(Huang Jing,黄精)for quality control.Methods The major compound was isolated and analyzed by liquid chromatography-mass spectrometry(LC-MS),and subsequently further identified by nuclear magnetic resonance(NMR).Thin layer chromatography(TLC)was optimized based on the previous methods reported in the Chinese Pharmacopeia(2015 edition).Results The major compound was isolated from the natural material and identified as linoleic acid.A high performance liquid chromatography(HPLC)method with robust linearity(R2=0.9997),specificity,precision,stability,repeatability and recovery was developed for linoleic acid determination.TLC chromatogram was improved significantly after optimization for qualitative analysis.Conclusions The optimized TLC method is practical and can be adopted for quality control of Polygonati Rhizoma(Huang Jing,黄精).The levels of linoleic acid vary between species of Polygonati Rhizoma(Huang Jing,黄精),with Polygonatum cyrtonema Hua(Jiang Xing Huang Jing,姜型黄精)showing the highest contents.This study provides valuable information for quality control of Polygonati Rhizoma(Huang Jing,黄精).展开更多
Camellia oil and olive oil with superior economic value are easily adulterated with other,cheaper oils.It is difficult to identify both oils by traditional methods because of their similar fatty acid profiles.In the p...Camellia oil and olive oil with superior economic value are easily adulterated with other,cheaper oils.It is difficult to identify both oils by traditional methods because of their similar fatty acid profiles.In the present study,a novel method for qualitative and quantitative analysis ofβ-sitosterol using GC/MS and GC/FID was developed to identify camellia oil and olive oil.The method validation ofβ-sitosterol analysis showed good linearity and satisfactory values for recovery,accuracy,precision,and repeatability.The linear regression coefficient(R^(2))of the calibration curve was 0.9985.An acceptable limit of detection(0.36 mg/100 g)and limit of quantification(1.20 mg/100 g)were achieved.The spiked recoveries were 95.0%to 100.3%.The relative standard deviation(RSD)of within-day precision was less than 3.26%,and the RSD of retention times and peak areas for repeatability were within 0.03%and 1.08%,respectively.The contents ofβ-sitosterol in virgin camellia oil and virgin olive oil were in the range of 14.1–30.2 mg/100 g and 94.3–173.2 mg/100 g,respectively,indicating that theβ-sitosterol content in the former is seven times that in the latter,andβ-sitosterol could be a potential marker for the authentication and adulteration detection of both oils.展开更多
We present a specific-window method to subtract the interference of water vapor on terahertz frequency-domain spectroscopy（THz-FDS） at ambient temperature and pressure. A continuous-wave spectrometer based on photom...We present a specific-window method to subtract the interference of water vapor on terahertz frequency-domain spectroscopy（THz-FDS） at ambient temperature and pressure. A continuous-wave spectrometer based on photomixing was utilized to obtain THz-FDS of methanol vapor in the range of 50–1200 GHz. The distinctly spaced absorption features in the neighborhood of atmospheric windows of transparency were selected to perform linear fitting versus the calculated absorption cross section and obtain the concentration of methanol. Furthermore, the gradually decreased methanol vapor was quantified to demonstrate the reliability of the method.展开更多
Laser-induced breakdown spectroscopy(LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may ev...Laser-induced breakdown spectroscopy(LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may eventually revolutionize the field of human health. Under normal circumstances, the elemental analysis of pharmaceutical products based on chemical methods is time-consuming and complicated. In this investigation, the principal aim is to develop an LIBS-based methodology for elemental analysis of pharmaceutical products. This LIBS technique was utilized for qualitative as well as quantitative analysis of the elements present in Ca-based tablets. All the elements present in the tablets were detected and their percentage compositions were verified in a single shot, using the proposed instrument. These elements(e.g., Ca, Mg, Fe, Zn, and others) were identified by the wavelengths of their spectral lines, which were verified using the NIST database. The approximate amount of each element was determined based on their observed peaks and the result was in exact agreement with the content specification. The determination of the composition of prescription drug for patients is highly important in numerous circumstances. For example, the exploitation of LIBS may facilitate elemental decomposition of medicines to determine the accuracy of the stated composition information. Moreover, the approach can provide element-specific, meaningful, and accurate information related to pharmaceutical products.展开更多
A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this a...A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this article, we analyze this problem and propose remedies. We use a real doping case to illustrate how chemical noise causes a serious selectivity problem, probably causing a false positive outcome.展开更多
Dear Editor,We read with a great interest the recently published systematic review by Shamsikhani and Hosseini titled,“Foot reflexology on nausea and vomiting:A systematic review.”[1]While the authors provided a com...Dear Editor,We read with a great interest the recently published systematic review by Shamsikhani and Hosseini titled,“Foot reflexology on nausea and vomiting:A systematic review.”[1]While the authors provided a comprehensive qualitative synthesis of six studies meeting their inclusion criteria,we believe that additional quantitative analysis would strengthen the evidence base for foot reflexology in managing nausea and vomiting.We conducted a complementary meta-analysis to provide quantitative evidence supporting the qualitative findings presented in the systematic review.展开更多
In order to identify the rock burst hazard in coalmine and thus to give a credible forecast, firstly, analyzed such effect factors as natural geological factors and mining technological conditions based on the investi...In order to identify the rock burst hazard in coalmine and thus to give a credible forecast, firstly, analyzed such effect factors as natural geological factors and mining technological conditions based on the investigation of more than one hundred mine rock burst cases. Secondly, adopted the fault tree analysis （FTA） technology to the mine rock burst hazard identification for the first time and confirmed twelve kinds of basic events, that is, the large mining depth, the burst-orientation coal seams, the solid strata of roof and bottom, near the faults with bigger fall, the folds, the change of seam thickness, other regional tectonics transformation or stress strip, the drilling, blasting and extracting operation, the unscientific extracting methods, the illogical extracting sequence, the residual pillars and the too close distance between the working face and the residual areas or the stopping extracting lines. Moreover, worked out the fault tree of mine rock burst. At last, it made qualitative analysis and quantitative analysis and forecasted the rock burst hazard according to the characteristic of geologic structure and exploitation technology conditions in certain mine of Shandong Province, China, the rock burst accidents happened in the following exploitation validated that it is of feasibility and veracity adopting FTA to identify the mine rock burst hazard.展开更多
Researches have proved that in human beings＇ actual languange communication, listening is the most important part. However, in English learning, listening seems always to be a weakness for many Chinese students. Engl...Researches have proved that in human beings＇ actual languange communication, listening is the most important part. However, in English learning, listening seems always to be a weakness for many Chinese students. English learning is a systematic process, during which, English listening proficience is influeced by many factors. Therefore, from the systematicness and inner relations in English learning and based on qualitative analysis and quantitative analysis between English listening and other English skills in English listening, this paper tries to give the correlation analysis and accordingly give some suggestions to improve listening proficiency for ESL （English as a second language） learners展开更多
Due to rapidly development of information systems, risk and security issues have increased and became a phenomenon that concerns every organization, without considering the size of it. To achieve desired results, mana...Due to rapidly development of information systems, risk and security issues have increased and became a phenomenon that concerns every organization, without considering the size of it. To achieve desired results, managers have to implement methods of evaluating and mitigating risk as part of a process well elaborated. Security risk management helps managers to better control the business practices and improve the business process. An effective risk management process is based on a successful IT security program. This doesn＇t mean that the main goal of an organization＇s risk management process is to protect its IT assets, but to protect the organization and its ability to perform their missions. During this process, managers have to take into consideration risks that can affect the organization and apply the most suitable measures to minimize their impact. The most important task is choosing the best suited method for analyzing the existing risk properly. Several methods have been developed, being classified in quantitative and qualitative approaches of evaluating risk. The purpose of this paper is to present the advantages and disadvantages of each approach taking current needs and opportunities into consideration.展开更多
基金supported by National Natural Science Foundation of China(Grant No.:32301161)the Natural Scientific Foundation of Hunan Province,China(Grant No.:2023JJ60052)+3 种基金the Scientific Research Project of Hunan Provincial Health Commission,China(Grant No.:202112062218,20190161)the Scientific Research Project of Hunan Provincial Department of Education,China(Grant No.:22B0455)the Clinical“4310”Project of the University of South China,China(Grant No.:20224310NHYCG02)the Doctoral Scientific Research Foundation of University of South China,China(Grant No.:200XQD042).
文摘Infrared(IR)spectroscopy,a technique within the realm of molecular vibrational spectroscopy,furnishes distinctive chemical signatures pivotal for both structural analysis and compound identification.A notable challenge emerges from the misalignment between the mid-IR light wavelength range and molecular dimensions,culminating in a constrained absorption cross-section and diminished vibrational absorption coefficients(Supplementary data).
基金Key Projects in the National Science & Technology Pillar Program during the 11thFive-Year Plan Period (Grant No.2008BAI51B02)National Natural Science Fund Project of China (Grant No. 81202904)
文摘Huang-Lian-Jie-Du-Decoction （HLJDD） has been widely used for the treatment of Alzheimer＇s disease （AD） in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not clearly clarified yet. In present study, the water extract of HLJDD and subsequent three polarity fractions divided by different reagents were investigated. A total of 17 chromatographic peaks were confirmed by comparison with standards and their UV, MS spectra. Among them, 11 major compounds were determined by HPLC-DAD method with good linear regression relationship （r2, 0.9994-0.9999）, precisions （inter-day precision RSD, 0.79%-1.07%; intra-day precision RSD, 1.59%-2.10%）, repeatability （RSD, 1.66%-3.67%）, stability （RSD, 1.26%-4.77%） and recovery （95.24%-105.41%, RSD, 0.29%-2.69%）. Furthermore, PC12 cells and primary neurons cells were used for the neuroprotective effective assessment of aforementioned four samples from HLJDD. 3＂he total aqueous extract and n-butanol extract of HLJDD presented more significant effects than the other two parts. According to their quality and quantity determination results, iridoids and alkaloids have a positive correlation with the neuroprotective effectiveness of HLJDD.
基金Supported by the National Natural Science Foundation of China(No30725045)the Foundation of Eleventh Five-Year-Plan of China(No2008ZX09202-002)+1 种基金the Shanghai Leading Academic Discipline Project, China(NoB906)the Scientific Foundation of Shanghai City, China(No07DZ19702)
文摘A combined method of high performance liquid chromatograph-elecrtrospray-ionization mass spectrometer（HPLC-ESI-MS/MS） coupled with a photodiode array detector（HPLC-DAD） and principal component analysis（PCA） was applied to the qualitative and quantitative analyses of alkaloids in Cortex Phellodendri（CP） samples, and to the differentiation of two species of CP, Cortex Phellodendri Chinensis（CPC） and Cortex Phellodendri Amurensis（CPA）. Twenty-two peaks appeared in the HPLC-MS base peak chromatogram of CP detected by the HPLC-ESI-MS/MS analysis, and the alkaloids were identified according to the MSn data, the known MS fragmentation rules and the literature data. Five alkaloids including berberine, palmatine, jatrorrhizine, phellodendrine and magnoflorine were simultaneously determinated by the HPLC-DAD. Berberine was the primary component in all CP samples, and the contents of berberine and palmatine were exploited to be two critical parameters for effective discrimination between the two species of CP. The average content of berberine in CPC（58.75 mg/g） was higher than that in CPA（9.16 mg/g）, while the content of palmatine was less, only 0.25 mg/g in CPC and 4.19 mg/g in CPA. With the use of PCA, samples datasets were separated successfully into two different clusters corresponding to the two species, and berberine, pahnatine, phellodendrine and magnoflorine contribute most to the above mentioned calssifying . The proposed method oroved to be a useful tool in the aualitv control of Chinese herbal medicines.
基金We thank for the funding support from the National Standardization Construction in TCMs of China(No.ZYBZH-Y-HUN-23)National Key Research and Development Projects of China(No.2018YFC1707903)Key Research and Development Projects of Hunan Province(No.2018SK2119).
文摘Objective To explore the major compound in Polygonati Rhizoma(Huang Jing,黄精)for quality control.Methods The major compound was isolated and analyzed by liquid chromatography-mass spectrometry(LC-MS),and subsequently further identified by nuclear magnetic resonance(NMR).Thin layer chromatography(TLC)was optimized based on the previous methods reported in the Chinese Pharmacopeia(2015 edition).Results The major compound was isolated from the natural material and identified as linoleic acid.A high performance liquid chromatography(HPLC)method with robust linearity(R2=0.9997),specificity,precision,stability,repeatability and recovery was developed for linoleic acid determination.TLC chromatogram was improved significantly after optimization for qualitative analysis.Conclusions The optimized TLC method is practical and can be adopted for quality control of Polygonati Rhizoma(Huang Jing,黄精).The levels of linoleic acid vary between species of Polygonati Rhizoma(Huang Jing,黄精),with Polygonatum cyrtonema Hua(Jiang Xing Huang Jing,姜型黄精)showing the highest contents.This study provides valuable information for quality control of Polygonati Rhizoma(Huang Jing,黄精).
基金This research was funded by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province(No.2023C02044)Zhejiang Province Key Research and Development Program(No.2021C02032)Zhejiang Provincial Natural Science Foundation(No.LQ20C200013),China.
文摘Camellia oil and olive oil with superior economic value are easily adulterated with other,cheaper oils.It is difficult to identify both oils by traditional methods because of their similar fatty acid profiles.In the present study,a novel method for qualitative and quantitative analysis ofβ-sitosterol using GC/MS and GC/FID was developed to identify camellia oil and olive oil.The method validation ofβ-sitosterol analysis showed good linearity and satisfactory values for recovery,accuracy,precision,and repeatability.The linear regression coefficient(R^(2))of the calibration curve was 0.9985.An acceptable limit of detection(0.36 mg/100 g)and limit of quantification(1.20 mg/100 g)were achieved.The spiked recoveries were 95.0%to 100.3%.The relative standard deviation(RSD)of within-day precision was less than 3.26%,and the RSD of retention times and peak areas for repeatability were within 0.03%and 1.08%,respectively.The contents ofβ-sitosterol in virgin camellia oil and virgin olive oil were in the range of 14.1–30.2 mg/100 g and 94.3–173.2 mg/100 g,respectively,indicating that theβ-sitosterol content in the former is seven times that in the latter,andβ-sitosterol could be a potential marker for the authentication and adulteration detection of both oils.
基金supported by the China Postdoctoral Science Foundation(No.2017M610771)
文摘We present a specific-window method to subtract the interference of water vapor on terahertz frequency-domain spectroscopy（THz-FDS） at ambient temperature and pressure. A continuous-wave spectrometer based on photomixing was utilized to obtain THz-FDS of methanol vapor in the range of 50–1200 GHz. The distinctly spaced absorption features in the neighborhood of atmospheric windows of transparency were selected to perform linear fitting versus the calculated absorption cross section and obtain the concentration of methanol. Furthermore, the gradually decreased methanol vapor was quantified to demonstrate the reliability of the method.
文摘Laser-induced breakdown spectroscopy(LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may eventually revolutionize the field of human health. Under normal circumstances, the elemental analysis of pharmaceutical products based on chemical methods is time-consuming and complicated. In this investigation, the principal aim is to develop an LIBS-based methodology for elemental analysis of pharmaceutical products. This LIBS technique was utilized for qualitative as well as quantitative analysis of the elements present in Ca-based tablets. All the elements present in the tablets were detected and their percentage compositions were verified in a single shot, using the proposed instrument. These elements(e.g., Ca, Mg, Fe, Zn, and others) were identified by the wavelengths of their spectral lines, which were verified using the NIST database. The approximate amount of each element was determined based on their observed peaks and the result was in exact agreement with the content specification. The determination of the composition of prescription drug for patients is highly important in numerous circumstances. For example, the exploitation of LIBS may facilitate elemental decomposition of medicines to determine the accuracy of the stated composition information. Moreover, the approach can provide element-specific, meaningful, and accurate information related to pharmaceutical products.
文摘A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this article, we analyze this problem and propose remedies. We use a real doping case to illustrate how chemical noise causes a serious selectivity problem, probably causing a false positive outcome.
文摘Dear Editor,We read with a great interest the recently published systematic review by Shamsikhani and Hosseini titled,“Foot reflexology on nausea and vomiting:A systematic review.”[1]While the authors provided a comprehensive qualitative synthesis of six studies meeting their inclusion criteria,we believe that additional quantitative analysis would strengthen the evidence base for foot reflexology in managing nausea and vomiting.We conducted a complementary meta-analysis to provide quantitative evidence supporting the qualitative findings presented in the systematic review.
文摘In order to identify the rock burst hazard in coalmine and thus to give a credible forecast, firstly, analyzed such effect factors as natural geological factors and mining technological conditions based on the investigation of more than one hundred mine rock burst cases. Secondly, adopted the fault tree analysis （FTA） technology to the mine rock burst hazard identification for the first time and confirmed twelve kinds of basic events, that is, the large mining depth, the burst-orientation coal seams, the solid strata of roof and bottom, near the faults with bigger fall, the folds, the change of seam thickness, other regional tectonics transformation or stress strip, the drilling, blasting and extracting operation, the unscientific extracting methods, the illogical extracting sequence, the residual pillars and the too close distance between the working face and the residual areas or the stopping extracting lines. Moreover, worked out the fault tree of mine rock burst. At last, it made qualitative analysis and quantitative analysis and forecasted the rock burst hazard according to the characteristic of geologic structure and exploitation technology conditions in certain mine of Shandong Province, China, the rock burst accidents happened in the following exploitation validated that it is of feasibility and veracity adopting FTA to identify the mine rock burst hazard.
文摘Researches have proved that in human beings＇ actual languange communication, listening is the most important part. However, in English learning, listening seems always to be a weakness for many Chinese students. English learning is a systematic process, during which, English listening proficience is influeced by many factors. Therefore, from the systematicness and inner relations in English learning and based on qualitative analysis and quantitative analysis between English listening and other English skills in English listening, this paper tries to give the correlation analysis and accordingly give some suggestions to improve listening proficiency for ESL （English as a second language） learners
文摘Due to rapidly development of information systems, risk and security issues have increased and became a phenomenon that concerns every organization, without considering the size of it. To achieve desired results, managers have to implement methods of evaluating and mitigating risk as part of a process well elaborated. Security risk management helps managers to better control the business practices and improve the business process. An effective risk management process is based on a successful IT security program. This doesn＇t mean that the main goal of an organization＇s risk management process is to protect its IT assets, but to protect the organization and its ability to perform their missions. During this process, managers have to take into consideration risks that can affect the organization and apply the most suitable measures to minimize their impact. The most important task is choosing the best suited method for analyzing the existing risk properly. Several methods have been developed, being classified in quantitative and qualitative approaches of evaluating risk. The purpose of this paper is to present the advantages and disadvantages of each approach taking current needs and opportunities into consideration.
