Rapeseed is widely grown in China as an important oil crop. In this study, Shotgun lipidomic methodology based on tandem mass spectrometry but without liquid chromatography was established for simple lipids analysis s...Rapeseed is widely grown in China as an important oil crop. In this study, Shotgun lipidomic methodology based on tandem mass spectrometry but without liquid chromatography was established for simple lipids analysis such as mono-, di-and triacylglycerols(MAGs, DAGs and TAGs) and the derivatives such as free fatty acids(FFAs). Six varieties of rapeseeds belonging to 3 types(B. juncea, B. campestris and B. oleracea) from different areas of China were investigated, with 59 TAG species, 10 DAG species, 5 MAG species and 6 FFA species identified. It was found that erucic acid was mainly present in the form of TAG 62:4(22:1/18:2/22:1), TAG 62:3(22:1/18:1/22:1), and TAG 62:5(22:1/18:3/22:1) in high erucic acid rapeseed oils, while oleic acid was mainly present in the form of TAG 54:2(18:0/18:1/18:1), and TAG 54:4(18:1/18:2/18:1) in high oleic acid rapeseed oils. It was difficult for DAG, MAG and FFA quantification due to their low content with high background content of TAGs. Results showed that the main differences in lipids were not derived from the types of rapeseed, but directly related to varieties.展开更多
As a current analytical instrument for lipidomics profiling with high sensitivity, selectivity, and throughput, mass spectrometry (MS) has been widely used in the field of clinical medicine, nutrition, bromatology, bo...As a current analytical instrument for lipidomics profiling with high sensitivity, selectivity, and throughput, mass spectrometry (MS) has been widely used in the field of clinical medicine, nutrition, bromatology, botany and etc. During the routine use of shotgun- MS and high performance liquid chromatography-MS (HPLC-MS) in lipid analysis, an important problem to be solved is the defective repeatability and stability resulting from signal attenuation or drifts in LC-peak shape and retention time of MS platform. To remove or minimize the influence, extensively accepted and applied QC (quality control) samples must be performed. In this review, we emphasize the importance of the application of QC samples, which could 1) provide the ability to equilibrate the analytical platform at the beginning; 2) act as a quality assurance (QA) procedure during the analytical process; 3) perform signal correction in the data handling with the purpose of reducing analytical variation and improving the precision of quantitative analysis; 4) the data between different laboratories can be compared through the incorporation of particular QC samples-Standard Reference Material (SRM) 1950. In addition, we display 4 types and requirements of QC samples during quality control in lipidomics profiling. Lipidomics profiling based on MS strongly requires commonly accepted guidelines for quality control to perform routine, large-scale researches, so as to integrate data from different scientists for more information.展开更多
The effects of the coefficient of friction and coefficient of restitution on the static packing characteristics of a polydisperse spherical pebble bed are numerically investigated using the discrete element method.Sev...The effects of the coefficient of friction and coefficient of restitution on the static packing characteristics of a polydisperse spherical pebble bed are numerically investigated using the discrete element method.Several important static packing characteristics under different coefficients of friction and restitution are presented and discussed.The results show that the coefficients of friction and restitution impose opposite effects on the packing heights and global packing factor.Neither the coefficient of friction nor restitution affected the oscillation width of the wall,whereas their effects are primarily reflected in the oscillation amplitude of the radial local packing factor and the axial local packing factor distribution at the top of the pebble bed.In both the contact force distribution and coordination number distribution,a left-shifted phenomenon appearing as the coefficient of friction occurred,and only the magnitude of the maximum frequency is affected when the coefficient of restitution changed from 0.1 to 0.9.In all simulation cases,the effects of the coefficients of friction and restitution are similar to that of cross-impact.展开更多
基金supported by National Natural Science Foundation of China(Grant No 21105119)Research Foundation of the Director General of Oil Crops Research Institute,Chinese Academy of Agricultural Sciences
文摘Rapeseed is widely grown in China as an important oil crop. In this study, Shotgun lipidomic methodology based on tandem mass spectrometry but without liquid chromatography was established for simple lipids analysis such as mono-, di-and triacylglycerols(MAGs, DAGs and TAGs) and the derivatives such as free fatty acids(FFAs). Six varieties of rapeseeds belonging to 3 types(B. juncea, B. campestris and B. oleracea) from different areas of China were investigated, with 59 TAG species, 10 DAG species, 5 MAG species and 6 FFA species identified. It was found that erucic acid was mainly present in the form of TAG 62:4(22:1/18:2/22:1), TAG 62:3(22:1/18:1/22:1), and TAG 62:5(22:1/18:3/22:1) in high erucic acid rapeseed oils, while oleic acid was mainly present in the form of TAG 54:2(18:0/18:1/18:1), and TAG 54:4(18:1/18:2/18:1) in high oleic acid rapeseed oils. It was difficult for DAG, MAG and FFA quantification due to their low content with high background content of TAGs. Results showed that the main differences in lipids were not derived from the types of rapeseed, but directly related to varieties.
文摘As a current analytical instrument for lipidomics profiling with high sensitivity, selectivity, and throughput, mass spectrometry (MS) has been widely used in the field of clinical medicine, nutrition, bromatology, botany and etc. During the routine use of shotgun- MS and high performance liquid chromatography-MS (HPLC-MS) in lipid analysis, an important problem to be solved is the defective repeatability and stability resulting from signal attenuation or drifts in LC-peak shape and retention time of MS platform. To remove or minimize the influence, extensively accepted and applied QC (quality control) samples must be performed. In this review, we emphasize the importance of the application of QC samples, which could 1) provide the ability to equilibrate the analytical platform at the beginning; 2) act as a quality assurance (QA) procedure during the analytical process; 3) perform signal correction in the data handling with the purpose of reducing analytical variation and improving the precision of quantitative analysis; 4) the data between different laboratories can be compared through the incorporation of particular QC samples-Standard Reference Material (SRM) 1950. In addition, we display 4 types and requirements of QC samples during quality control in lipidomics profiling. Lipidomics profiling based on MS strongly requires commonly accepted guidelines for quality control to perform routine, large-scale researches, so as to integrate data from different scientists for more information.
基金This study was supported by the Collaborative Innovation Program of Hefei Science Center,Chinese Academy of Sciences,under grant number 2019HSC-CIP006.
文摘The effects of the coefficient of friction and coefficient of restitution on the static packing characteristics of a polydisperse spherical pebble bed are numerically investigated using the discrete element method.Several important static packing characteristics under different coefficients of friction and restitution are presented and discussed.The results show that the coefficients of friction and restitution impose opposite effects on the packing heights and global packing factor.Neither the coefficient of friction nor restitution affected the oscillation width of the wall,whereas their effects are primarily reflected in the oscillation amplitude of the radial local packing factor and the axial local packing factor distribution at the top of the pebble bed.In both the contact force distribution and coordination number distribution,a left-shifted phenomenon appearing as the coefficient of friction occurred,and only the magnitude of the maximum frequency is affected when the coefficient of restitution changed from 0.1 to 0.9.In all simulation cases,the effects of the coefficients of friction and restitution are similar to that of cross-impact.
