Electrochemical detection of 3-methyl-4-nitrophenol (MNP) in direct phenol oxidation occurs at high potentials and generally leads to progressive passivation of the electrochemical sensor. This study describes the use...Electrochemical detection of 3-methyl-4-nitrophenol (MNP) in direct phenol oxidation occurs at high potentials and generally leads to progressive passivation of the electrochemical sensor. This study describes the use of a carbon fiber microelectrode modified with a tetrasulfonated nickel phthalocyanine complex for the detection of MNP at a lower potential than that of direct phenol oxidation. The MNP voltammogram showed the presence of an anodic peak at -0.11 V vs SCE, corresponding to the oxidation of the hydroxylamine group generated after the reduction of the nitro group. The effect of buffer pH on the peak current and SWV parameters such as frequency, scan increment, and pulse amplitude were studied and optimized to have better electrochemical response of the proposed sensor. With these optimal parameters, the calibration curve shows that the peak current varied linearly as a function of MNP concentration, leading to a limit of detection (LoD) of 1.1 μg/L. These results show an appreciable sensitivity of the sensor for detecting the MNP at relatively low potentials, making it possible to avoid passivation phenomena.展开更多
目的研究在没有对照品的情况下鉴定检材中1-(4-氟苯基)-2-(N-吡咯烷基)-1-戊酮[1-(4-fluorophenyl)-2-(1-pyrrolidinyl)pentan-1-one,4-F-α-PVP]类似物1-(4-氟-3甲基苯基)-2-(N-吡咯烷基)-1-戊酮[1-(4-fluoro-3-methyl phenyl)-2-(1-py...目的研究在没有对照品的情况下鉴定检材中1-(4-氟苯基)-2-(N-吡咯烷基)-1-戊酮[1-(4-fluorophenyl)-2-(1-pyrrolidinyl)pentan-1-one,4-F-α-PVP]类似物1-(4-氟-3甲基苯基)-2-(N-吡咯烷基)-1-戊酮[1-(4-fluoro-3-methyl phenyl)-2-(1-pyrrolidinyl)pentan-1-one,4-F-3-Methyl-α-PVP]盐酸盐的方法。方法综合利用直接进样电子电离-质谱(electron ionization-mass spectrometry,EI-MS)、GCMS、电喷雾离子化-高分辨质谱(electrospray ionization-high resolution mass spectrometry,ESI-HRMS)、超高效液相色谱-高分辨串联质谱(ultra-high performance liquid chromatography-high resolution tandem mass spectrometry,UPLC-HRMS/MS)、核磁共振(nuclear magnetic resonance,NMR)、离子色谱和傅里叶变换红外光谱法(Fourier transform infrared spectroscopy,FTIR),实现对检材中未知化合物的结构解析与表征,并对该化合物在EI-MS和UPLC-HRMS/MS两种质谱分析方式下生成碎片离子的裂解机制进行推导。结果通过对检材中化合物的直接进样EI-MS、GC-MS、ESI-HRMS和UPLC-HRMS/MS分析,推断出未知化合物为4-F-α-PVP的结构类似物,可能苯环中多了1个甲基。根据核磁共振氢谱(1H-nuclear magnetic reso⁃nance,1 H-NMR)、核磁共振碳谱(13C-nuclear magnetic resonance,13C-NMR)等分析结果,进一步证明了甲基的位置在苯环的3-位。由于1H-NMR分析中实际氢的个数比4-F-3-Methyl-α-PVP中性分子多1个,推断该化合物以盐形式存在。离子色谱法分析结果表明该化合物含氯离子(含量11.14%~11.16%),结合FTIR对主要官能团信息的结构分析,最终确定该未知化合物为4-F-3-Methyl-α-PVP盐酸盐。结论建立了综合利用EI-MS、GC-MS、ESI-HRMS、UPLC-HRMS/MS、NMR、离子色谱和FTIR鉴定检材中4-F-3-Methyl-α-PVP盐酸盐的方法,将有助于法庭科学实验室在案件中鉴定该物质或其他具有类似结构的化合物。展开更多
Background:It has been demonstrated that thymosinβ4(Tβ4)could inflect the severity of acute-on-chronic hepatitis B liver failure(ACHBLF),but the relationship between its methylation status and the prognosis of liver...Background:It has been demonstrated that thymosinβ4(Tβ4)could inflect the severity of acute-on-chronic hepatitis B liver failure(ACHBLF),but the relationship between its methylation status and the prognosis of liver failure is not clear.This study aimed to determine Tβ4 promoter methylation status in patients with ACHBLF and to evaluate its prognostic value.Methods:The study recruited 115 patients with ACHBLF,80 with acute-on-chronic hepatitis B pre-liver failure(pre-ACHBLF),and 86 with chronic hepatitis B(CHB).In addition,there were 36 healthy controls(HCs)from the Department of Hepatology,Qilu Hospital of Shandong University.The 115 patients with ACHBLF were divided into three subgroups:33 with early stage ACHBLF(E-ACHBLF),42 with mid-stage ACHBLF(M-ACHBLF),and 40 with advanced stage ACHBLF(A-ACHBLF).Tβ4 promoter methylation status in peripheral blood mononuclear cells(PBMCs)was measured by methylation-specific polymerase chain reaction,and mRNA was detected by quantitative real-time polymerase chain reaction.Results:Methylation frequency of Tβ4 was significantly higher in patients with ACHBLF than in those with pre-ACHBLF,CHB or HCs.However,expression of Tβ4 mRNA showed the opposite trend.In patients with ACHBLF,Tβ4 promoter methylation status correlated negatively with mRNA levels.The 3-month mortality of ACHBLF in the methylated group was significantly higher than that in the unmethylated group.Also,Tβ4 promoter methylation frequency was lower in survivors than in non-survivors.When used to predict the 1-,2-,and 3-month incidence of ACHBLF,Tβ4 methylation status was better than the model for end-stage liver disease(MELD)score.The predictive value of Tβ4 methylation was higher than that of MELD score for the mortality of patients with E-ACHBLF and M-ACHBLF,but not for A-ACHBLF.Conclusions:Tβ4 methylation might be an important early marker for predicting disease incidence and prognosis in patients with ACHBLF.展开更多
BACKGROUND We previously demonstrated that heat shock factor protein 4(HSF4)facilitates colorectal cancer(CRC)progression.DNA methylation,a major modifier of gene expression and stability,is involved in CRC developmen...BACKGROUND We previously demonstrated that heat shock factor protein 4(HSF4)facilitates colorectal cancer(CRC)progression.DNA methylation,a major modifier of gene expression and stability,is involved in CRC development and outcome.AIM To investigate the correlation between HSF4 methylation and CRC risk,and to uncover the underlying molecular mechanisms.METHODS Differences in β values of HSF4 methylation loci in multiple malignancies and their correlation with HSF4 mRNA expression were analyzed based on Shiny Methylation Analysis Resource Tool.HSF4 methylation-related genes were identified by LinkedOmics in CRC,and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed.Protein-protein interaction network of HSF4 methylation-related genes was constructed by String database and MCODE algorithm.RESULTS A total of 19 CpG methylation loci were identified in HSF4,and their β values were significantly increased in CRC tissues and exhibited a positive correlation with HSF4 mRNA expression.Unfortunately,the prognostic and diagnostic performance of these CpG loci in CRC patients was mediocre.In CRC,there were 1694 HSF4 methylation-related genes;1468 of which displayed positive and 226 negative associations,and they were involved in regulating phenotypes such as immune,inflammatory,and metabolic reprogramming.EGFR,RELA,STAT3,FCGR3A,POLR2K,and AXIN1 are hub genes among the HSF4 methylation-related genes.CONCLUSION HSF4 is highly methylated in CRC,but there is no significant correlation between it and the prognosis and diagnosis of CRC.HSF4 methylation may serve as one of the ways in which HSF4 mediates the CRC process.展开更多
4-Hydroxybenzoate （4HBA） is a naturally occurring aromatic compound, as a key intermediate metabolite not only for natural products but also for arti- ficial products. There are four metabolic pathways for 4HBA： pr...4-Hydroxybenzoate （4HBA） is a naturally occurring aromatic compound, as a key intermediate metabolite not only for natural products but also for arti- ficial products. There are four metabolic pathways for 4HBA： protocatechuate cleavage pathway; catechol cleavage pathway; anaerobic degradation pathway in anaerobes ; and gentisate cleavage pathway. The last pathway including a NIH shift reaction remains to be elucidated. In this review we emphasized on the NIH shift reaction involved in the 4HBA degrdation. The key enzymes of each 4HBA metabolic pathway also were introduced. Finnaly, we described the thermophilic Bacillus sp. B1 strain which was capable of degrading varous aromatic compounds including gHBA, and presented a direction for the research of NIH shift reaction.展开更多
New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<s...New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).展开更多
文摘Electrochemical detection of 3-methyl-4-nitrophenol (MNP) in direct phenol oxidation occurs at high potentials and generally leads to progressive passivation of the electrochemical sensor. This study describes the use of a carbon fiber microelectrode modified with a tetrasulfonated nickel phthalocyanine complex for the detection of MNP at a lower potential than that of direct phenol oxidation. The MNP voltammogram showed the presence of an anodic peak at -0.11 V vs SCE, corresponding to the oxidation of the hydroxylamine group generated after the reduction of the nitro group. The effect of buffer pH on the peak current and SWV parameters such as frequency, scan increment, and pulse amplitude were studied and optimized to have better electrochemical response of the proposed sensor. With these optimal parameters, the calibration curve shows that the peak current varied linearly as a function of MNP concentration, leading to a limit of detection (LoD) of 1.1 μg/L. These results show an appreciable sensitivity of the sensor for detecting the MNP at relatively low potentials, making it possible to avoid passivation phenomena.
文摘目的研究在没有对照品的情况下鉴定检材中1-(4-氟苯基)-2-(N-吡咯烷基)-1-戊酮[1-(4-fluorophenyl)-2-(1-pyrrolidinyl)pentan-1-one,4-F-α-PVP]类似物1-(4-氟-3甲基苯基)-2-(N-吡咯烷基)-1-戊酮[1-(4-fluoro-3-methyl phenyl)-2-(1-pyrrolidinyl)pentan-1-one,4-F-3-Methyl-α-PVP]盐酸盐的方法。方法综合利用直接进样电子电离-质谱(electron ionization-mass spectrometry,EI-MS)、GCMS、电喷雾离子化-高分辨质谱(electrospray ionization-high resolution mass spectrometry,ESI-HRMS)、超高效液相色谱-高分辨串联质谱(ultra-high performance liquid chromatography-high resolution tandem mass spectrometry,UPLC-HRMS/MS)、核磁共振(nuclear magnetic resonance,NMR)、离子色谱和傅里叶变换红外光谱法(Fourier transform infrared spectroscopy,FTIR),实现对检材中未知化合物的结构解析与表征,并对该化合物在EI-MS和UPLC-HRMS/MS两种质谱分析方式下生成碎片离子的裂解机制进行推导。结果通过对检材中化合物的直接进样EI-MS、GC-MS、ESI-HRMS和UPLC-HRMS/MS分析,推断出未知化合物为4-F-α-PVP的结构类似物,可能苯环中多了1个甲基。根据核磁共振氢谱(1H-nuclear magnetic reso⁃nance,1 H-NMR)、核磁共振碳谱(13C-nuclear magnetic resonance,13C-NMR)等分析结果,进一步证明了甲基的位置在苯环的3-位。由于1H-NMR分析中实际氢的个数比4-F-3-Methyl-α-PVP中性分子多1个,推断该化合物以盐形式存在。离子色谱法分析结果表明该化合物含氯离子(含量11.14%~11.16%),结合FTIR对主要官能团信息的结构分析,最终确定该未知化合物为4-F-3-Methyl-α-PVP盐酸盐。结论建立了综合利用EI-MS、GC-MS、ESI-HRMS、UPLC-HRMS/MS、NMR、离子色谱和FTIR鉴定检材中4-F-3-Methyl-α-PVP盐酸盐的方法,将有助于法庭科学实验室在案件中鉴定该物质或其他具有类似结构的化合物。
基金supported by grants from the Key Project of the Chinese Ministry of Science and Technology(2017ZX102022022)the National Natural Science Foundation of China(81970522)the Key Research and Development Project of Shandong Province(2019GSF108023).
文摘Background:It has been demonstrated that thymosinβ4(Tβ4)could inflect the severity of acute-on-chronic hepatitis B liver failure(ACHBLF),but the relationship between its methylation status and the prognosis of liver failure is not clear.This study aimed to determine Tβ4 promoter methylation status in patients with ACHBLF and to evaluate its prognostic value.Methods:The study recruited 115 patients with ACHBLF,80 with acute-on-chronic hepatitis B pre-liver failure(pre-ACHBLF),and 86 with chronic hepatitis B(CHB).In addition,there were 36 healthy controls(HCs)from the Department of Hepatology,Qilu Hospital of Shandong University.The 115 patients with ACHBLF were divided into three subgroups:33 with early stage ACHBLF(E-ACHBLF),42 with mid-stage ACHBLF(M-ACHBLF),and 40 with advanced stage ACHBLF(A-ACHBLF).Tβ4 promoter methylation status in peripheral blood mononuclear cells(PBMCs)was measured by methylation-specific polymerase chain reaction,and mRNA was detected by quantitative real-time polymerase chain reaction.Results:Methylation frequency of Tβ4 was significantly higher in patients with ACHBLF than in those with pre-ACHBLF,CHB or HCs.However,expression of Tβ4 mRNA showed the opposite trend.In patients with ACHBLF,Tβ4 promoter methylation status correlated negatively with mRNA levels.The 3-month mortality of ACHBLF in the methylated group was significantly higher than that in the unmethylated group.Also,Tβ4 promoter methylation frequency was lower in survivors than in non-survivors.When used to predict the 1-,2-,and 3-month incidence of ACHBLF,Tβ4 methylation status was better than the model for end-stage liver disease(MELD)score.The predictive value of Tβ4 methylation was higher than that of MELD score for the mortality of patients with E-ACHBLF and M-ACHBLF,but not for A-ACHBLF.Conclusions:Tβ4 methylation might be an important early marker for predicting disease incidence and prognosis in patients with ACHBLF.
基金Supported by National Natural Science Foundation of China,No.82260601Joint Foundation of Kunming Medical University and Yunnan Provincial Science and Technology Department,No.202201AY070001-256+1 种基金Grant for Clinical Medical Center of Yunnan Provincial Health Commission,No.2021LCZXXF-XH03Young Academic Talents Cultivation Foundation of Yunnan Province,No.202205AC160070.
文摘BACKGROUND We previously demonstrated that heat shock factor protein 4(HSF4)facilitates colorectal cancer(CRC)progression.DNA methylation,a major modifier of gene expression and stability,is involved in CRC development and outcome.AIM To investigate the correlation between HSF4 methylation and CRC risk,and to uncover the underlying molecular mechanisms.METHODS Differences in β values of HSF4 methylation loci in multiple malignancies and their correlation with HSF4 mRNA expression were analyzed based on Shiny Methylation Analysis Resource Tool.HSF4 methylation-related genes were identified by LinkedOmics in CRC,and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed.Protein-protein interaction network of HSF4 methylation-related genes was constructed by String database and MCODE algorithm.RESULTS A total of 19 CpG methylation loci were identified in HSF4,and their β values were significantly increased in CRC tissues and exhibited a positive correlation with HSF4 mRNA expression.Unfortunately,the prognostic and diagnostic performance of these CpG loci in CRC patients was mediocre.In CRC,there were 1694 HSF4 methylation-related genes;1468 of which displayed positive and 226 negative associations,and they were involved in regulating phenotypes such as immune,inflammatory,and metabolic reprogramming.EGFR,RELA,STAT3,FCGR3A,POLR2K,and AXIN1 are hub genes among the HSF4 methylation-related genes.CONCLUSION HSF4 is highly methylated in CRC,but there is no significant correlation between it and the prognosis and diagnosis of CRC.HSF4 methylation may serve as one of the ways in which HSF4 mediates the CRC process.
基金Supported by the National Natural Science Foundation of China(31400099)Jiangsu Science and Technology Agency Project(BK20141148 and BK20140235)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘4-Hydroxybenzoate （4HBA） is a naturally occurring aromatic compound, as a key intermediate metabolite not only for natural products but also for arti- ficial products. There are four metabolic pathways for 4HBA： protocatechuate cleavage pathway; catechol cleavage pathway; anaerobic degradation pathway in anaerobes ; and gentisate cleavage pathway. The last pathway including a NIH shift reaction remains to be elucidated. In this review we emphasized on the NIH shift reaction involved in the 4HBA degrdation. The key enzymes of each 4HBA metabolic pathway also were introduced. Finnaly, we described the thermophilic Bacillus sp. B1 strain which was capable of degrading varous aromatic compounds including gHBA, and presented a direction for the research of NIH shift reaction.
文摘New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).
