With the energy parameters obtained from1H nuclear magnetic resonance(NMR)chemical shifts data by local composition model and coupled with azeotropic point,the low-pressure vapor-liquid equilibrium is satisfactorily p...With the energy parameters obtained from1H nuclear magnetic resonance(NMR)chemical shifts data by local composition model and coupled with azeotropic point,the low-pressure vapor-liquid equilibrium is satisfactorily predicted for alcohol+hexane,alcohol+cyclohexane,and alcohol+benzene binary systems at different temperatures.The relationship between the spectroscopic information and thermodynamic property is presented.展开更多
The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural pr...The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural prop- erties of highly toxic pesticides were investigated using the PreADME analysis. We observed that toxic pesticides possessed higher molecular weight and, more hydrogen bond donors and acceptors when compared with less toxic pesticides. The occurrence of functional groups and structural properties was analyzed using ~H-NMR. The ~H- NMR spectra of the phosphomethoxy class of pesticides were characterized by methyl resonances at 3.7-3.9 ppm （8） with the coupling constants of 11-16 Hz （Je-cns）. In phosphoethoxy pesticides, the methyl resonance was about 1.4 ppm （8） with the coupling constant of 10 Hz （Je-cH2） and the methylene resonances was 4.2-4.4 ppm （8） with the coupling constant of 0.8 Hz （Jp-cH3）, respectively. Our study shows that the values of four parameters such as chemical shift, coupling constant, integration and relaxation time correlated with the concentration of toxic pesticides, and can be used to characterise the proton groups in the molecular structures of toxic pesticides.展开更多
An approach for distinguishing two types of positional isomers of dimeric shikonin and its analogs was explored with ^(4)JC,H long-range correlation by prolonging the acquisition time at ^(2,3)JC,H values of 2.0 and 8...An approach for distinguishing two types of positional isomers of dimeric shikonin and its analogs was explored with ^(4)JC,H long-range correlation by prolonging the acquisition time at ^(2,3)JC,H values of 2.0 and 8.0Hz.Furthermore,the ^(1)H(proton)nuclear magnetic resonance(NMR)pattern of phenolic hydroxyl protons was developed as a“diagnosis signal”to ascertain the relative location of each side chain in DMSO-d_(6) at sample concentrations of 0.022-0.034 mol/L.The chemical shift differences of 0.6ppm between OH-5' and OH-1 and between OH-8'and OH-4 are assigned to Type A and Type B,respectively.All reported ambiguous structures were corrected by this pattern.Additionally,the steric structures of isolated compounds were elucidated by quantum chemical calculations of electronic circular dichroism(ECD)spectra.展开更多
The ^1 H nuclear magnetic resonance （^1 H NMR） fingerprints of fractionated non-polar extracts （control substance for a plant drug （CSPD） A） from Rhizoma chuanxiong, the rhizomes of Ligusticum chuanxiong Hort., ...The ^1 H nuclear magnetic resonance （^1 H NMR） fingerprints of fractionated non-polar extracts （control substance for a plant drug （CSPD） A） from Rhizoma chuanxiong, the rhizomes of Ligusticum chuanxiong Hort., of seven specimens from different sources were measured on Fourier Transform （FT）-NMR spectrometer and assigned by comparing them with the ^1 H NMR spectra of the isolated pure compounds. The ^1 H NMR fingerprints showed exclusively characteristic resonance signals of the major special constituents of the plant. Although the differences in the relative intensity of the ^1H NMR signals due to a discrepancy in the ratio of the major constituents among these samples could be confirmed by high performance liquid chromatography analysis, the general features of the ^1H NMR fingerprint established for an authentic sample of the rhizomes of L. chuanxiong e. hibited exclusive data from those special compounds and can be used for authenticating L. Chuanxiong species.展开更多
The morphology of some polyetherester-ureas were studied by ^(13)C CP/MAS and ~1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and ...The morphology of some polyetherester-ureas were studied by ^(13)C CP/MAS and ~1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and HMDI based ones have not. For HDI/MDI based polymers, the presented results suggest that the distribution of two kinds of hard segment units is mainly in a block form. The influences of the different hard segment and chain length on the mobility of the soft segment were also studied.展开更多
Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The pres...Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The present study aimed,therefore,to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance,breast meat quality attributes,incidence and severity of breast muscle myopathies and foot pad dermatitis(FPD),and plasma and muscle metabolomics profile in fast-growing broilers.Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet(CON,digestible Arg:Lys ratio of 1.05,1.05,1.06 and 1.07 in each feeding phase,respectively) or the same basal diet supplemented on-top with crystalline L-arginine(ARG,digestible Arg:Lys ratio of 1.15,1.15,1.16 and 1.17,respectively).Productive parameters were determined at the end of each feeding phase(12,22,33,43 d).At slaughter(43 d),incidence and severity of FPD and breast myopathies were assessed,while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonancespectroscopy.The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d(1.352 vs.1.401,P < 0.05),22 d(1.398 vs.1.420; P < 0.01) and 33 d(1.494 vs.1.524; P < 0.05),and also tended to improve it in the overall period of trial(1.646 vs.1.675; P = 0.09).Body weight was significantly increased in ARG compared to CON group at 33 d(1,884 vs.1,829 g; P < 0.05).No significant effect was observed on meat quality attributes,breast myopathies and FPD occurrence.ARG birds showed significantly higher plasma concentration of arginine and leucine,and lower of acetoacetate,glutamate,adenosine and proline.Arginine and acetate concentrations were higher,whereas acetone and inosine levels were lower in the breast of ARG birds(P < 0.05).Conclusions: Taken together,these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.展开更多
随着人民生活水平的不断提高,葡萄酒在我国广泛受到消费者的喜爱。近年来中国葡萄酒市场日渐壮大,假冒现象日渐严重,因此,开展葡萄酒的真实性研究也变得至关重要。本文综述了国内外近16年来核磁共振氢谱(^(1)H-nuclear magnetic resonan...随着人民生活水平的不断提高,葡萄酒在我国广泛受到消费者的喜爱。近年来中国葡萄酒市场日渐壮大,假冒现象日渐严重,因此,开展葡萄酒的真实性研究也变得至关重要。本文综述了国内外近16年来核磁共振氢谱(^(1)H-nuclear magnetic resonance,^(1)H-NMR)技术在葡萄酒真实性鉴别中的应用现状,重点阐述了^(1)H-NMR技术在葡萄酒产地、品种和年份真实性鉴别方面的研究进展,旨在为启迪和推动我国葡萄酒真实性鉴别及促进葡萄酒真实性鉴别的深入研究提供思路和借鉴。展开更多
A metabolically healthy status,whether obese or not,is a transient stage with the potential to develop into metabolic disor-ders during the course of life.We investigated the incidence of metabolic disorders in 1078 m...A metabolically healthy status,whether obese or not,is a transient stage with the potential to develop into metabolic disor-ders during the course of life.We investigated the incidence of metabolic disorders in 1078 metabolically healthy Chinese adults from the Shanghai Changfeng Study and looked for metabolites that discriminated the participants who would develop metabolic disorders in the future.Participants were divided into metabolically healthy overweight/obesity(MHO)and meta-bolically healthy normal weight(MHNW)groups according to their body mass index(BMI)and metabolic status.Their serum metabolomic profile was measured using a ^(1)H nuclear magnetic resonance spectrometer(^(1)H-NMR).The prevalence of diabetes,hypertriglyceridemia,hypercholesterolemia and metabolic syndrome was similar between the MHNW and MHO participants at baseline.After a median of 4.2 years of follow-up,more MHO participants became metabolically unhealthy than MHNW participants.However,a subgroup of MHO participants who remained metabolically healthy(MHO→MHO)had a similar prevalence of metabolic disorders as the MHNW participants at the follow-up examination,despite a signifi-cant reduction in their serum concentrations of high-density lipoprotein(HDL)and an elevation in valine,leucine,alanine and tyrosine.Further correlation analysis indicated that serum intermediate-density lipoprotein(IDL)and very low-density lipoprotein cholesterol(VLDL-CH)might be involved in the transition from metabolically healthy to unhealthy status and could be valuable to identify the MHNW and MHO with increased metabolic risks.展开更多
建立食用醋中乙酸含量的快速定量分析方法。采用核磁共振氢谱(^(1)H nuclear magnetic resonance,^(1)H NMR),对多种食用醋进行了测定。核磁共振氢谱(^(1)H-NMR)测定参数为:温度25℃,谱宽2~14ppm,脉冲角度45度,脉冲延迟时间3s,采样时间...建立食用醋中乙酸含量的快速定量分析方法。采用核磁共振氢谱(^(1)H nuclear magnetic resonance,^(1)H NMR),对多种食用醋进行了测定。核磁共振氢谱(^(1)H-NMR)测定参数为:温度25℃,谱宽2~14ppm,脉冲角度45度,脉冲延迟时间3s,采样时间2s,扫描次数16次。实验结果表明,在优化的测试条件下,目标物与内标物定量特征峰面积比1∶3~4∶1范围内,该方法表现出良好的线性关系,线性回归方程为Y=-0.01996+0.01732X(R=0.9999);精密度和重复性实验相对标准偏差(RSD)分别为0.059%和0.249%;样品加标回收率为97.8%~101.4%,平均偏差0.9%。该方法样品需求量小,结果稳定可靠,是一种简便、快捷的食用醋中乙酸含量的检测方法。展开更多
基金Supported by the Research Project Foundation of the Education Department of Zhejiang Province （20061157）, the Natural Science Foundation of Zhejiang Province （Y4090453）, and the Key Research Project Foundation of Shaoxing University.
文摘With the energy parameters obtained from1H nuclear magnetic resonance(NMR)chemical shifts data by local composition model and coupled with azeotropic point,the low-pressure vapor-liquid equilibrium is satisfactorily predicted for alcohol+hexane,alcohol+cyclohexane,and alcohol+benzene binary systems at different temperatures.The relationship between the spectroscopic information and thermodynamic property is presented.
文摘The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural prop- erties of highly toxic pesticides were investigated using the PreADME analysis. We observed that toxic pesticides possessed higher molecular weight and, more hydrogen bond donors and acceptors when compared with less toxic pesticides. The occurrence of functional groups and structural properties was analyzed using ~H-NMR. The ~H- NMR spectra of the phosphomethoxy class of pesticides were characterized by methyl resonances at 3.7-3.9 ppm （8） with the coupling constants of 11-16 Hz （Je-cns）. In phosphoethoxy pesticides, the methyl resonance was about 1.4 ppm （8） with the coupling constant of 10 Hz （Je-cH2） and the methylene resonances was 4.2-4.4 ppm （8） with the coupling constant of 0.8 Hz （Jp-cH3）, respectively. Our study shows that the values of four parameters such as chemical shift, coupling constant, integration and relaxation time correlated with the concentration of toxic pesticides, and can be used to characterise the proton groups in the molecular structures of toxic pesticides.
基金funded by the CAMS Innovation Fund for Medical Sciences(CIFMS,No.2021-I2M-1-028).
文摘An approach for distinguishing two types of positional isomers of dimeric shikonin and its analogs was explored with ^(4)JC,H long-range correlation by prolonging the acquisition time at ^(2,3)JC,H values of 2.0 and 8.0Hz.Furthermore,the ^(1)H(proton)nuclear magnetic resonance(NMR)pattern of phenolic hydroxyl protons was developed as a“diagnosis signal”to ascertain the relative location of each side chain in DMSO-d_(6) at sample concentrations of 0.022-0.034 mol/L.The chemical shift differences of 0.6ppm between OH-5' and OH-1 and between OH-8'and OH-4 are assigned to Type A and Type B,respectively.All reported ambiguous structures were corrected by this pattern.Additionally,the steric structures of isolated compounds were elucidated by quantum chemical calculations of electronic circular dichroism(ECD)spectra.
基金Supported by the National Natural Science Foundation of China (30630073)the Science Foundation of the State Administration of Traditional ChineseMedicine, China (02-03ZP09)
文摘The ^1 H nuclear magnetic resonance （^1 H NMR） fingerprints of fractionated non-polar extracts （control substance for a plant drug （CSPD） A） from Rhizoma chuanxiong, the rhizomes of Ligusticum chuanxiong Hort., of seven specimens from different sources were measured on Fourier Transform （FT）-NMR spectrometer and assigned by comparing them with the ^1 H NMR spectra of the isolated pure compounds. The ^1 H NMR fingerprints showed exclusively characteristic resonance signals of the major special constituents of the plant. Although the differences in the relative intensity of the ^1H NMR signals due to a discrepancy in the ratio of the major constituents among these samples could be confirmed by high performance liquid chromatography analysis, the general features of the ^1H NMR fingerprint established for an authentic sample of the rhizomes of L. chuanxiong e. hibited exclusive data from those special compounds and can be used for authenticating L. Chuanxiong species.
文摘The morphology of some polyetherester-ureas were studied by ^(13)C CP/MAS and ~1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and HMDI based ones have not. For HDI/MDI based polymers, the presented results suggest that the distribution of two kinds of hard segment units is mainly in a block form. The influences of the different hard segment and chain length on the mobility of the soft segment were also studied.
文摘Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The present study aimed,therefore,to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance,breast meat quality attributes,incidence and severity of breast muscle myopathies and foot pad dermatitis(FPD),and plasma and muscle metabolomics profile in fast-growing broilers.Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet(CON,digestible Arg:Lys ratio of 1.05,1.05,1.06 and 1.07 in each feeding phase,respectively) or the same basal diet supplemented on-top with crystalline L-arginine(ARG,digestible Arg:Lys ratio of 1.15,1.15,1.16 and 1.17,respectively).Productive parameters were determined at the end of each feeding phase(12,22,33,43 d).At slaughter(43 d),incidence and severity of FPD and breast myopathies were assessed,while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonancespectroscopy.The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d(1.352 vs.1.401,P < 0.05),22 d(1.398 vs.1.420; P < 0.01) and 33 d(1.494 vs.1.524; P < 0.05),and also tended to improve it in the overall period of trial(1.646 vs.1.675; P = 0.09).Body weight was significantly increased in ARG compared to CON group at 33 d(1,884 vs.1,829 g; P < 0.05).No significant effect was observed on meat quality attributes,breast myopathies and FPD occurrence.ARG birds showed significantly higher plasma concentration of arginine and leucine,and lower of acetoacetate,glutamate,adenosine and proline.Arginine and acetate concentrations were higher,whereas acetone and inosine levels were lower in the breast of ARG birds(P < 0.05).Conclusions: Taken together,these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.
文摘随着人民生活水平的不断提高,葡萄酒在我国广泛受到消费者的喜爱。近年来中国葡萄酒市场日渐壮大,假冒现象日渐严重,因此,开展葡萄酒的真实性研究也变得至关重要。本文综述了国内外近16年来核磁共振氢谱(^(1)H-nuclear magnetic resonance,^(1)H-NMR)技术在葡萄酒真实性鉴别中的应用现状,重点阐述了^(1)H-NMR技术在葡萄酒产地、品种和年份真实性鉴别方面的研究进展,旨在为启迪和推动我国葡萄酒真实性鉴别及促进葡萄酒真实性鉴别的深入研究提供思路和借鉴。
基金supported by the Shanghai Municipal Science and Technology Major Project(2017SHZDZX01)the Science and Technology Commission of Shanghai Municipality(16JC1400500).
文摘A metabolically healthy status,whether obese or not,is a transient stage with the potential to develop into metabolic disor-ders during the course of life.We investigated the incidence of metabolic disorders in 1078 metabolically healthy Chinese adults from the Shanghai Changfeng Study and looked for metabolites that discriminated the participants who would develop metabolic disorders in the future.Participants were divided into metabolically healthy overweight/obesity(MHO)and meta-bolically healthy normal weight(MHNW)groups according to their body mass index(BMI)and metabolic status.Their serum metabolomic profile was measured using a ^(1)H nuclear magnetic resonance spectrometer(^(1)H-NMR).The prevalence of diabetes,hypertriglyceridemia,hypercholesterolemia and metabolic syndrome was similar between the MHNW and MHO participants at baseline.After a median of 4.2 years of follow-up,more MHO participants became metabolically unhealthy than MHNW participants.However,a subgroup of MHO participants who remained metabolically healthy(MHO→MHO)had a similar prevalence of metabolic disorders as the MHNW participants at the follow-up examination,despite a signifi-cant reduction in their serum concentrations of high-density lipoprotein(HDL)and an elevation in valine,leucine,alanine and tyrosine.Further correlation analysis indicated that serum intermediate-density lipoprotein(IDL)and very low-density lipoprotein cholesterol(VLDL-CH)might be involved in the transition from metabolically healthy to unhealthy status and could be valuable to identify the MHNW and MHO with increased metabolic risks.
文摘建立食用醋中乙酸含量的快速定量分析方法。采用核磁共振氢谱(^(1)H nuclear magnetic resonance,^(1)H NMR),对多种食用醋进行了测定。核磁共振氢谱(^(1)H-NMR)测定参数为:温度25℃,谱宽2~14ppm,脉冲角度45度,脉冲延迟时间3s,采样时间2s,扫描次数16次。实验结果表明,在优化的测试条件下,目标物与内标物定量特征峰面积比1∶3~4∶1范围内,该方法表现出良好的线性关系,线性回归方程为Y=-0.01996+0.01732X(R=0.9999);精密度和重复性实验相对标准偏差(RSD)分别为0.059%和0.249%;样品加标回收率为97.8%~101.4%,平均偏差0.9%。该方法样品需求量小,结果稳定可靠,是一种简便、快捷的食用醋中乙酸含量的检测方法。
