The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides...The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.展开更多
In recent years, numerous theoretical tandem mass spectrometry prediction methods have been proposed, yet a systematic study and evaluation of their theoretical accuracy limits have not been conducted. If the accuracy...In recent years, numerous theoretical tandem mass spectrometry prediction methods have been proposed, yet a systematic study and evaluation of their theoretical accuracy limits have not been conducted. If the accuracy of current methods approaches this limit, further exploration of new prediction techniques may become redundant. Conversely, a need for more precise prediction methods or models may be indicated. In this study, we have experimentally analyzed the limits of accuracy at different numbers of ions and parameters using repeated spectral pairs and integrating various similarity metrics. Results show significant achievements in accuracy for backbone ion methods with room for improvement. In contrast, full-spectrum prediction methods exhibit greater potential relative to the theoretical accuracy limit. Additionally, findings highlight the significant impact of normalized collision energy and instrument type on prediction accuracy, underscoring the importance of considering these factors in future theoretical tandem mass spectrometry predictions.展开更多
BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.neg...BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development.展开更多
[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived f...[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.展开更多
基质辅助激光解吸电离飞行时间质谱(Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry,MALDI-TOF MS)技术是临床微生物诊断中的一项革命性创新技术,给临床微生物诊断带来了极大的便利,同时也给临床微生...基质辅助激光解吸电离飞行时间质谱(Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry,MALDI-TOF MS)技术是临床微生物诊断中的一项革命性创新技术,给临床微生物诊断带来了极大的便利,同时也给临床微生物实习带教带来了新的挑战。本文阐述了MALDI-TOF MS技术在临床微生物检验实习带教中的应用探讨,旨在充分运用MALDI-TOF MS技术结合传统鉴定技术,提高临床微生物检验实习的教学能力。展开更多
目的:研究比较两种基质辅助激光解吸电离飞行时间质谱仪(Autof ms 1000与MALDI Biotyper)对临床常见丝状病原真菌鉴定的准确性和效率。方法:共纳入32株丝状病原真菌标准菌株和120株临床分离菌株,按照标准操作方法分别用Autof ms 1000与M...目的:研究比较两种基质辅助激光解吸电离飞行时间质谱仪(Autof ms 1000与MALDI Biotyper)对临床常见丝状病原真菌鉴定的准确性和效率。方法:共纳入32株丝状病原真菌标准菌株和120株临床分离菌株,按照标准操作方法分别用Autof ms 1000与MALDI Biotyper对相关菌株进行鉴定,对相关结果及测序分子鉴定结果进行对比分析。结果:在种水平上,Autof ms 1000质谱仪共检出140株丝状病原真菌,检出正确率为92.1%(140/152),其中126株分值在9.0以上,2株出现错误鉴定,误鉴定比例为1.3%(2/152);MALDI Biotyper质谱仪共正确检出98株,检出正确率为64.4%,2.0分以上的菌株47株,仅3株鉴定分值大于2.3分,7株出现误鉴定。结论:Autof ms 1000与MALDI Biotyper这两种质谱鉴定系统均能用于临床常见丝状病原真菌的快速鉴定,而Autof ms 1000质谱仪更具优势。展开更多
目的探讨基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)结合短时培养在快速鉴定血流感染病原菌中的应用。方法对南京医科大学附属淮安第一医院微生物...目的探讨基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)结合短时培养在快速鉴定血流感染病原菌中的应用。方法对南京医科大学附属淮安第一医院微生物室2020年11月至2021年12月血培养报告阳性的标本进行革兰染色分类,并采用4h和6h短时培养法及MALDI-TOF MS技术快速鉴定感染病原菌并实时报送病区单元。结果4h短时培养革兰阴性菌共351株,339株(96.6%)细菌鉴定到种属,与24h鉴定结果相同,11株无鉴定结果,1株鉴定错误;6h短时培养革兰阳性菌共216株,212株(98.1%)鉴定到种属,与24h鉴定结果相同,3株无鉴定结果,1株鉴定错误。跟踪321株革兰阴性菌的临床反馈,287例(89.4%)给予临床关注,89例(27.7%)进行药物调整,238例(74.1%)临床疗效良好;跟踪183株革兰阳性菌的临床反馈,其中150例(82.0%)给予临床关注,49例(26.8%)进行药物调整,131例(71.6%)临床疗效良好。结论MALDI-TOF MS技术结合短时培养方法可有效提高血流感染病原菌鉴定准确率,改善血流感染患者抗菌药物治疗时机。展开更多
Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 pat...Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 patients with stage Ⅰ lung adenocarcinoma and 17 age-and sex-matched healthy controls,and the serum proteomic profiles were obtained by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Results Compared with healthy control group,two highly expressed potential biomarkers were identified with the relative molecular weights of 6 631.64 Da and 4 964.21 Da. The two best novel protein peaks were automatically chosen for the system training and the development of the constructed model. The constructed model was then used to test an independent set of masked serum samples from 15 lung adenocarcinoma patients and 22 healthy individuals. The analysis yielded a sensitivity of 93.3%,and a specificity of 95.5%. Conclusion These results suggest that MALDI-TOF-MS ProteinChip technology is a quick,convenient,and high-output analyzing method that is capable of selecting several relatively potential biomarkers from the serum of lung adenocarcinoma patients and may have a clinical value in the future,and will provide clues to identifying new serologic biomarkers of lung adenocarcinoma.展开更多
Three-dimensional(3D)cell spheroid models combined with mass spectrometry imaging(MSI)enables innovative investigation of in vivo-like biological processes under different physiological and pathological conditions.Her...Three-dimensional(3D)cell spheroid models combined with mass spectrometry imaging(MSI)enables innovative investigation of in vivo-like biological processes under different physiological and pathological conditions.Herein,airflow-assisted desorption electrospray ionization-MSI(AFADESI-MSI)was coupled with 3D HepG2 spheroids to assess the metabolism and hepatotoxicity of amiodarone(AMI).High-coverage imaging of>1100 endogenous metabolites in hepatocyte spheroids was achieved using AFADESI-MSI.Following AMI treatment at different times,15 metabolites of AMI involved in Ndesethylation,hydroxylation,deiodination,and desaturation metabolic reactions were identified,and according to their spatiotemporal dynamics features,the metabolic pathways of AMI were proposed.Subsequently,the temporal and spatial changes in metabolic disturbance within spheroids caused by drug exposure were obtained via metabolomic analysis.The main dysregulated metabolic pathways included arachidonic acid and glycerophospholipid metabolism,providing considerable evidence for the mechanism of AMI hepatotoxicity.In addition,a biomarker group of eight fatty acids was selected that provided improved indication of cell viability and could characterize the hepatotoxicity of AMI.The combination of AFADESI-MSI and HepG2 spheroids can simultaneously obtain spatiotemporal information for drugs,drug metabolites,and endogenous metabolites after AMI treatment,providing an effective tool for in vitro drug hepatotoxicity evaluation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12125509,12222514,11961141003,and 12005304)National Key Research and Development Project(No.2022YFA1602301)+1 种基金CAST Young Talent Support Planthe CNNC Science Fund for Talented Young Scholars Continuous support for basic scientific research projects。
文摘The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.
文摘In recent years, numerous theoretical tandem mass spectrometry prediction methods have been proposed, yet a systematic study and evaluation of their theoretical accuracy limits have not been conducted. If the accuracy of current methods approaches this limit, further exploration of new prediction techniques may become redundant. Conversely, a need for more precise prediction methods or models may be indicated. In this study, we have experimentally analyzed the limits of accuracy at different numbers of ions and parameters using repeated spectral pairs and integrating various similarity metrics. Results show significant achievements in accuracy for backbone ion methods with room for improvement. In contrast, full-spectrum prediction methods exhibit greater potential relative to the theoretical accuracy limit. Additionally, findings highlight the significant impact of normalized collision energy and instrument type on prediction accuracy, underscoring the importance of considering these factors in future theoretical tandem mass spectrometry predictions.
文摘BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development.
基金Supported by Scientific Research Project of Dalian Customs(2022DK09).
文摘[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.
文摘基质辅助激光解吸电离飞行时间质谱(Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry,MALDI-TOF MS)技术是临床微生物诊断中的一项革命性创新技术,给临床微生物诊断带来了极大的便利,同时也给临床微生物实习带教带来了新的挑战。本文阐述了MALDI-TOF MS技术在临床微生物检验实习带教中的应用探讨,旨在充分运用MALDI-TOF MS技术结合传统鉴定技术,提高临床微生物检验实习的教学能力。
文摘目的:研究比较两种基质辅助激光解吸电离飞行时间质谱仪(Autof ms 1000与MALDI Biotyper)对临床常见丝状病原真菌鉴定的准确性和效率。方法:共纳入32株丝状病原真菌标准菌株和120株临床分离菌株,按照标准操作方法分别用Autof ms 1000与MALDI Biotyper对相关菌株进行鉴定,对相关结果及测序分子鉴定结果进行对比分析。结果:在种水平上,Autof ms 1000质谱仪共检出140株丝状病原真菌,检出正确率为92.1%(140/152),其中126株分值在9.0以上,2株出现错误鉴定,误鉴定比例为1.3%(2/152);MALDI Biotyper质谱仪共正确检出98株,检出正确率为64.4%,2.0分以上的菌株47株,仅3株鉴定分值大于2.3分,7株出现误鉴定。结论:Autof ms 1000与MALDI Biotyper这两种质谱鉴定系统均能用于临床常见丝状病原真菌的快速鉴定,而Autof ms 1000质谱仪更具优势。
文摘目的探讨基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)结合短时培养在快速鉴定血流感染病原菌中的应用。方法对南京医科大学附属淮安第一医院微生物室2020年11月至2021年12月血培养报告阳性的标本进行革兰染色分类,并采用4h和6h短时培养法及MALDI-TOF MS技术快速鉴定感染病原菌并实时报送病区单元。结果4h短时培养革兰阴性菌共351株,339株(96.6%)细菌鉴定到种属,与24h鉴定结果相同,11株无鉴定结果,1株鉴定错误;6h短时培养革兰阳性菌共216株,212株(98.1%)鉴定到种属,与24h鉴定结果相同,3株无鉴定结果,1株鉴定错误。跟踪321株革兰阴性菌的临床反馈,287例(89.4%)给予临床关注,89例(27.7%)进行药物调整,238例(74.1%)临床疗效良好;跟踪183株革兰阳性菌的临床反馈,其中150例(82.0%)给予临床关注,49例(26.8%)进行药物调整,131例(71.6%)临床疗效良好。结论MALDI-TOF MS技术结合短时培养方法可有效提高血流感染病原菌鉴定准确率,改善血流感染患者抗菌药物治疗时机。
文摘Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 patients with stage Ⅰ lung adenocarcinoma and 17 age-and sex-matched healthy controls,and the serum proteomic profiles were obtained by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Results Compared with healthy control group,two highly expressed potential biomarkers were identified with the relative molecular weights of 6 631.64 Da and 4 964.21 Da. The two best novel protein peaks were automatically chosen for the system training and the development of the constructed model. The constructed model was then used to test an independent set of masked serum samples from 15 lung adenocarcinoma patients and 22 healthy individuals. The analysis yielded a sensitivity of 93.3%,and a specificity of 95.5%. Conclusion These results suggest that MALDI-TOF-MS ProteinChip technology is a quick,convenient,and high-output analyzing method that is capable of selecting several relatively potential biomarkers from the serum of lung adenocarcinoma patients and may have a clinical value in the future,and will provide clues to identifying new serologic biomarkers of lung adenocarcinoma.
基金funded by the National Natural Science Foundation of China(Grant No.:21874156)the Chinese Academy of Medical Science(CAMS)Innovation Fund for Medical Sciences(Grant No.:2021-1-I2M-028).
文摘Three-dimensional(3D)cell spheroid models combined with mass spectrometry imaging(MSI)enables innovative investigation of in vivo-like biological processes under different physiological and pathological conditions.Herein,airflow-assisted desorption electrospray ionization-MSI(AFADESI-MSI)was coupled with 3D HepG2 spheroids to assess the metabolism and hepatotoxicity of amiodarone(AMI).High-coverage imaging of>1100 endogenous metabolites in hepatocyte spheroids was achieved using AFADESI-MSI.Following AMI treatment at different times,15 metabolites of AMI involved in Ndesethylation,hydroxylation,deiodination,and desaturation metabolic reactions were identified,and according to their spatiotemporal dynamics features,the metabolic pathways of AMI were proposed.Subsequently,the temporal and spatial changes in metabolic disturbance within spheroids caused by drug exposure were obtained via metabolomic analysis.The main dysregulated metabolic pathways included arachidonic acid and glycerophospholipid metabolism,providing considerable evidence for the mechanism of AMI hepatotoxicity.In addition,a biomarker group of eight fatty acids was selected that provided improved indication of cell viability and could characterize the hepatotoxicity of AMI.The combination of AFADESI-MSI and HepG2 spheroids can simultaneously obtain spatiotemporal information for drugs,drug metabolites,and endogenous metabolites after AMI treatment,providing an effective tool for in vitro drug hepatotoxicity evaluation.
