DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation ...DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.展开更多
DNA methylation,especially methylation of cytosine in eukaryotic organisms,has been implicated in gene regulation,genomic imprinting,the timing of DNA replication,and determination of chromatin structure.It was report...DNA methylation,especially methylation of cytosine in eukaryotic organisms,has been implicated in gene regulation,genomic imprinting,the timing of DNA replication,and determination of chromatin structure.It was reported that 6.5% of the whole cytosine residues in the nuclear DNA in展开更多
Analysis of patient＇s materials like cells or nucleic acids obtained in a minimally invasive or noninvasive manner through the sampling of blood or other body fluids serves as liquid biopsies, which has huge potentia...Analysis of patient＇s materials like cells or nucleic acids obtained in a minimally invasive or noninvasive manner through the sampling of blood or other body fluids serves as liquid biopsies, which has huge potential for numerous diagnostic applications. Circulating cell-free DNA（cfDNA） is explored as a prognostic or predictive marker of liquid biopsies with the improvements in genomic and molecular methods. DNA methylation is an important epigenetic marker known to affect gene expression. cfDNA methylation detection is a very promising approach as abnormal distribution of DNA methylation is one of the hallmarks of many cancers and methylation changes occur early during carcinogenesis. This re？view summarizes the various investigational applications of cfDNA methylation and its oxidized de？rivatives as biomarkers for cancer diagnosis, prenatal diagnosis and organ transplantation monitoring.The review also provides a brief overview of the technologies for cfDNA methylation analysis based on next generation sequencing.展开更多
A mixture of oligosaccharide and glycopeptide was isolated from the aqueous extract of Panax ginseng roots. The mixture inhibits protein tyrosinc phosphatase（SHP-1） function, implying it enhances immune activity. Th...A mixture of oligosaccharide and glycopeptide was isolated from the aqueous extract of Panax ginseng roots. The mixture inhibits protein tyrosinc phosphatase（SHP-1） function, implying it enhances immune activity. The peak molecular mass of the oligosaccharide portion is 1800 calculated via GPC software after separation by HPLC. And the structure of the oligosaccharide portion is the backbone of （1→3）- and （1→4）-linked arabinopyranoside, and （1→4）- and （1→6）-linked glucopyranoside, with non-reducing terminals of arabinopyranoside and glucopyranoside. The peak molecular mass of glycopeptide portion is 1900 calculated via GPC software after separation by HPLC. The structure of glycopeptide portion is the backbone of （1→3）- and （1→4）-linked arabinopyranoside, and （1→3,6）-linked glucopyranoside, with non-reducing terminals of galactopyranose and glucopyranoside. The peptide composition is Glu. Asp, Hyp, Set, Arg, Gly , Thr, Pro, Ala, Val, lie, Leu and Lys. The oligosaccharide-peptide linkage is formed by Ara and Hyp.展开更多
The polysaccharide was isolated from Hypnea pannosa which was grown in Okinawa, Japan. The yield of the polysaccharide was 17.2%, and the total carbohydrates, pyruvic acid, sulfuric acid and ash contents were 55.2%, 3...The polysaccharide was isolated from Hypnea pannosa which was grown in Okinawa, Japan. The yield of the polysaccharide was 17.2%, and the total carbohydrates, pyruvic acid, sulfuric acid and ash contents were 55.2%, 3.8%, 35.2% and 24.3%, respectively. 3,6-Anhydro-α-D-galactose, β-D-galactose, α-D-galactose and D-glucose were identified by liquid and thin-layer chromatography. Fourier transform infrared (FTIR) spectra of the polysaccharide resembled that of ι-carrageenan. From the <sup>1</sup>H- and <sup>13</sup>C-NMR spectra, 1,3-linked β-D-galactose, 1,4-linked anhydro-α-D-galactose, 1,4-linked α-D-galactose, 1,4-linked β-D-glucose and pyruvic acid (carboxyl acetal, methyl proton and methyl carbon) were assigned. Methylation analysis revealed terminal D-galactose 0.1 mol), 1,4-linked D-glucose (1.0 mol) and 1,2,3,4,6-linked D-galactose (3.7 mol) for native polysaccharide, and terminal D-galactose, 1,4-linked D-galactose (1.9 mol), 1,4-linked D-glucose (1.0 mol), 1,3- linked D-galactose (1.7 mol), and 1,3,4,6-linked D-galactose (0.3 mol) which substituted with pyruvate group at 4 and 6 positions for desulfated polysaccharide. The polysaccharide was the novel pyruvated glucogalactan sulfate, the structure of which was proposed.展开更多
The thermal decomposition characteristics of methyl linoleate （ML） under nitrogen and oxygen atmo- spheres were investigated, using a thermogravimetric analyzer at a heating rate of 10 ~C/min from room tem- perature...The thermal decomposition characteristics of methyl linoleate （ML） under nitrogen and oxygen atmo- spheres were investigated, using a thermogravimetric analyzer at a heating rate of 10 ~C/min from room tem- perature to 600℃. Furthermore, the pyrolytic and kinetic characteristics of ML at different heating rates were stud- ied. The results showed that the thermal decomposition characteristics of ML under nitrogen and oxygen atmo- spheres were macroscopically similar, although ML exhibited relatively lower thermal stability under an oxy- gen atmosphere than under a nitrogen atmosphere. The initial decomposition temperature, the maximum weight loss temperature, the peak decomposition temperature, and the rate of maximum weight loss of ML under an oxygen atmosphere were much lower than those under a nitrogen atmosphere and increased with increasing heating rates under either oxygen or nitrogen atmosphere. In addition, the kinetic characteristics of thermal decomposition of ML were elucidated based on the experimental results and by the multiple linear regression method. The activation energy, pre-exponential factor, reaction order, and the kinetic equation for thermal decomposition of ML were obtained. The comparison of experimental and calculated data and the analysis of statistical errors of pyrolysis ratios demonstrated that the kinetic model was reliable for pyrolysis of ML with relative errors of about 1%. Finally, the kinetic compensation effect between the pre-exponential factors and the activation energy in the pyrolysis of ML was also confirmed.展开更多
The proposition of cancer cells in a tumor sample,named as tumor purity,is an intrinsic factor of tumor samples and has potentially great influence in variety of analyses including differential methylation,subclonal d...The proposition of cancer cells in a tumor sample,named as tumor purity,is an intrinsic factor of tumor samples and has potentially great influence in variety of analyses including differential methylation,subclonal deconvolution and subtype clustering.Infinium-Purify is an integrated R package for estimating and accounting for tumor purity based on DNA methylation Infinium 450 k array data.InfiniumPurify has three main functions getPurity,InfiniumDMC and InfiniumClust,which could infer tumor purity,differential methylation analysis and tumor sample cluster accounting for estimated or user-provided tumor purities,respectively.The InfiniumPurify package provides a comprehensive analysis of tumor purity in cancer methylation research.展开更多
The structure of a saccharide component (Abs), with pronounced activity of improving immunity system, isolated from the root of Achyranthes bidentata Blume, a traditional Chinese herbal medicine, was studied. Based on...The structure of a saccharide component (Abs), with pronounced activity of improving immunity system, isolated from the root of Achyranthes bidentata Blume, a traditional Chinese herbal medicine, was studied. Based on C-13 NMR, HPLC, and methylation analyses, Abs was shown to be a mixture of short-chain fructans with an average dp of 8, containing more (2-->B) than (2-->1) linked beta-D-fructofuranosyl residues, with branching at O-6 or O-1 of 18% of the D-fructofuranosyl residues.展开更多
基金support from the National Key R&D Program of China(Grant No.2018YFE0118700)the National Natural Science Foundation of China(NSFC Grant No.62174119)+1 种基金the 111 Project(Grant No.B07014)the Foundation for Talent Scientists of Nanchang Institute for Microtechnology of Tianjin University.
文摘DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.
文摘DNA methylation,especially methylation of cytosine in eukaryotic organisms,has been implicated in gene regulation,genomic imprinting,the timing of DNA replication,and determination of chromatin structure.It was reported that 6.5% of the whole cytosine residues in the nuclear DNA in
基金supported by grants from the National Basic Research Program of China(MOST2016YFC0900301 and 2014CB964900)the National Natural Science Foundation of China(No. 91519325)the Beijing Natural Science Foundation (No. 5162012)
文摘Analysis of patient＇s materials like cells or nucleic acids obtained in a minimally invasive or noninvasive manner through the sampling of blood or other body fluids serves as liquid biopsies, which has huge potential for numerous diagnostic applications. Circulating cell-free DNA（cfDNA） is explored as a prognostic or predictive marker of liquid biopsies with the improvements in genomic and molecular methods. DNA methylation is an important epigenetic marker known to affect gene expression. cfDNA methylation detection is a very promising approach as abnormal distribution of DNA methylation is one of the hallmarks of many cancers and methylation changes occur early during carcinogenesis. This re？view summarizes the various investigational applications of cfDNA methylation and its oxidized de？rivatives as biomarkers for cancer diagnosis, prenatal diagnosis and organ transplantation monitoring.The review also provides a brief overview of the technologies for cfDNA methylation analysis based on next generation sequencing.
基金Supported by the National Science & Technology Pillar Program of China(No2007BA138B00)
文摘A mixture of oligosaccharide and glycopeptide was isolated from the aqueous extract of Panax ginseng roots. The mixture inhibits protein tyrosinc phosphatase（SHP-1） function, implying it enhances immune activity. The peak molecular mass of the oligosaccharide portion is 1800 calculated via GPC software after separation by HPLC. And the structure of the oligosaccharide portion is the backbone of （1→3）- and （1→4）-linked arabinopyranoside, and （1→4）- and （1→6）-linked glucopyranoside, with non-reducing terminals of arabinopyranoside and glucopyranoside. The peak molecular mass of glycopeptide portion is 1900 calculated via GPC software after separation by HPLC. The structure of glycopeptide portion is the backbone of （1→3）- and （1→4）-linked arabinopyranoside, and （1→3,6）-linked glucopyranoside, with non-reducing terminals of galactopyranose and glucopyranoside. The peptide composition is Glu. Asp, Hyp, Set, Arg, Gly , Thr, Pro, Ala, Val, lie, Leu and Lys. The oligosaccharide-peptide linkage is formed by Ara and Hyp.
文摘The polysaccharide was isolated from Hypnea pannosa which was grown in Okinawa, Japan. The yield of the polysaccharide was 17.2%, and the total carbohydrates, pyruvic acid, sulfuric acid and ash contents were 55.2%, 3.8%, 35.2% and 24.3%, respectively. 3,6-Anhydro-α-D-galactose, β-D-galactose, α-D-galactose and D-glucose were identified by liquid and thin-layer chromatography. Fourier transform infrared (FTIR) spectra of the polysaccharide resembled that of ι-carrageenan. From the <sup>1</sup>H- and <sup>13</sup>C-NMR spectra, 1,3-linked β-D-galactose, 1,4-linked anhydro-α-D-galactose, 1,4-linked α-D-galactose, 1,4-linked β-D-glucose and pyruvic acid (carboxyl acetal, methyl proton and methyl carbon) were assigned. Methylation analysis revealed terminal D-galactose 0.1 mol), 1,4-linked D-glucose (1.0 mol) and 1,2,3,4,6-linked D-galactose (3.7 mol) for native polysaccharide, and terminal D-galactose, 1,4-linked D-galactose (1.9 mol), 1,4-linked D-glucose (1.0 mol), 1,3- linked D-galactose (1.7 mol), and 1,3,4,6-linked D-galactose (0.3 mol) which substituted with pyruvate group at 4 and 6 positions for desulfated polysaccharide. The polysaccharide was the novel pyruvated glucogalactan sulfate, the structure of which was proposed.
基金the financial support provided by National Natural Science Foundation of China (Project No.51375491)the Natural Science Foundation of Chongqing (Project No.CSTC,2014JCYJAA50021)
文摘The thermal decomposition characteristics of methyl linoleate （ML） under nitrogen and oxygen atmo- spheres were investigated, using a thermogravimetric analyzer at a heating rate of 10 ~C/min from room tem- perature to 600℃. Furthermore, the pyrolytic and kinetic characteristics of ML at different heating rates were stud- ied. The results showed that the thermal decomposition characteristics of ML under nitrogen and oxygen atmo- spheres were macroscopically similar, although ML exhibited relatively lower thermal stability under an oxy- gen atmosphere than under a nitrogen atmosphere. The initial decomposition temperature, the maximum weight loss temperature, the peak decomposition temperature, and the rate of maximum weight loss of ML under an oxygen atmosphere were much lower than those under a nitrogen atmosphere and increased with increasing heating rates under either oxygen or nitrogen atmosphere. In addition, the kinetic characteristics of thermal decomposition of ML were elucidated based on the experimental results and by the multiple linear regression method. The activation energy, pre-exponential factor, reaction order, and the kinetic equation for thermal decomposition of ML were obtained. The comparison of experimental and calculated data and the analysis of statistical errors of pyrolysis ratios demonstrated that the kinetic model was reliable for pyrolysis of ML with relative errors of about 1%. Finally, the kinetic compensation effect between the pre-exponential factors and the activation energy in the pyrolysis of ML was also confirmed.
基金This project was partially supported by the National Natural Science Foundation of China(61702325 and 61572327)Shanghai Science and Technology Innovation Action Plan(16391902900)National Institute of Health(R01GM122083).
文摘The proposition of cancer cells in a tumor sample,named as tumor purity,is an intrinsic factor of tumor samples and has potentially great influence in variety of analyses including differential methylation,subclonal deconvolution and subtype clustering.Infinium-Purify is an integrated R package for estimating and accounting for tumor purity based on DNA methylation Infinium 450 k array data.InfiniumPurify has three main functions getPurity,InfiniumDMC and InfiniumClust,which could infer tumor purity,differential methylation analysis and tumor sample cluster accounting for estimated or user-provided tumor purities,respectively.The InfiniumPurify package provides a comprehensive analysis of tumor purity in cancer methylation research.
基金Project supported by the State Science and Technology Commission of China.
文摘The structure of a saccharide component (Abs), with pronounced activity of improving immunity system, isolated from the root of Achyranthes bidentata Blume, a traditional Chinese herbal medicine, was studied. Based on C-13 NMR, HPLC, and methylation analyses, Abs was shown to be a mixture of short-chain fructans with an average dp of 8, containing more (2-->B) than (2-->1) linked beta-D-fructofuranosyl residues, with branching at O-6 or O-1 of 18% of the D-fructofuranosyl residues.
