The optical stability of chiral 2-hydroxy-2-phenylacetic acid in electron ionization mass spectrometry(EIMS) process has been detected directly by deuterium labelling technique. From the EI mass spectrum of deuterated...The optical stability of chiral 2-hydroxy-2-phenylacetic acid in electron ionization mass spectrometry(EIMS) process has been detected directly by deuterium labelling technique. From the EI mass spectrum of deuterated 2-hydroxy-2-phenylacetic acid, the major characteristic fragment ion at m/z 108(the capture of the carbonyl group) and the corresponding isotopic ion(13C) at m/z 109 can be observed, and the ratio of m/z=109 to m/z=108 is about 8%(the calculated value is 7.8%). As enolization of deuterated 2-hydroxy-2-phenylacetic acid in mass spectrometry can yield the characteristic fragment ion at m/z 109 and results in much higher ratio of 109/108 than 8%; this study shows that no enolization takes place during the EI-MS process of 2-hydroxy-2-phenylacetic acid. This results can be concluded that these compounds are optically stable in the process of instantaneous vaporization at high temperature and electron impact ionization.展开更多
[ Objective ] The aim of the research was to study the expression profile changes of genes involved in lipid metabolism pathway during liver regeneration in mice. [ Method] The CCI4 induced mouse model of liver regene...[ Objective ] The aim of the research was to study the expression profile changes of genes involved in lipid metabolism pathway during liver regeneration in mice. [ Method] The CCI4 induced mouse model of liver regeneration was established and the total RNA was isolated from liver tissue of mouse. Then the changes of genes involved in lipid metabolism pathway during different stages of liver regeneration were detected through micro-array chip gene technique and their specific functions were also analyzed. [ Result] Dudng the process of liver regeneration, the expression level of 98 genes involved in lipid metabolism pathway changed, which were divided into eight groups according to change trend. In the mass, the expression of genes was inhibited in the early stage and up-regulated in the late phase. And the gene expression associated with fatty acid synthesis pathway was mainly up-regulated while the catabolic pathway did not change significantly. Most of genes involved in bile acid synthesis pathway were suppressed before 4.5 d and up-regulated after 4.5 d or 7 d. [ Conclusion] During the process of liver regeneration, the genes associated with lipid metabolism are expressed in different trends, and this data should provide a specific range of genes for further studying the regulation effect of lipid metabolism related pathway on liver regeneration.展开更多
The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fl...The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fluoride film on EN deposition were studied additionally.The results show that the fluoride film on magnesium alloys is a kind of porous film composed of MgF2 with thickness of 1.6-3.2 μm.The composition of the activation bath and pretreatment of EN processing have influence on the composition of the fluoride film.The fluoride is stable and dissolves little in EN bath;as a result,the fluoride film can protect magnesium substrate from the corrosion of EN bath.The composition of fluoride determines the initial deposition of EN and part of the fluoride film finally exists as inclusion in EN coating.展开更多
Lignins were isolated and purified from alkali treated prehydrolysate of corn stover. The paper presents the structural features of lignins in a series purification processes. Fourier transform infrared spectroscopy, ...Lignins were isolated and purified from alkali treated prehydrolysate of corn stover. The paper presents the structural features of lignins in a series purification processes. Fourier transform infrared spectroscopy, ultraviolet-vis spectroscopy and proton nuclear magnetic resonance spectroscopy were used to analyze the chemical structure. Thermogravimetric analysis was applied to follow the thermal degradation, and wet chemical method was used to determine the sugar content. The results showed that the crude lignin from the prehydrolysate of corn stover was a heterogeneous material of syringyl, guaiacyl and p-hydroxyphenyl units, containing associated polysaccharides, lipids, and melted salts. Some of the crude lignin was chemically linked to hemicelluloses （mainly xylan）. The lipids in crude lignin were probably composed of saturated and/or unsaturated long carbon chains, fatty acids, tdterpenols, waxes, and derivatives of aromatic. The sugar content of purified lignin was less than 2.11%, mainly composed of guaiacyl units. DTGmax of purified lignin was 359 ℃. The majority of the hydroxyl groups were phenolic hydroxyl groups. The main type of linkages in purified lignin was β-O-4. Other types of linkages included β-5, β-β and α-O-4.展开更多
Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of gene...Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of generating a class of substances of interest for fine chemistry （ketones, aldehydes, alcohols, phenols, etc.）. From biomass, it is possible to produce bio-oil using pyrolysis, a thermodegradation process. The quality of the bio-oil depends on the process conditions （pyrolysis temperature, heating temperature, etc.） and biomass used. In this paper, the pyrolysis （using a fixed bed reactor） of three biomasses （coconut fiber, coffee grounds and sugar cane straw） is studied. The results indicated that the bio-oil yields for all biomass were similar, approximately 37%. The chemical profile obtained by gas chromatography coupled with mass spectrometry （GC/qMS） showed high amounts of fatty acids in the coffee grounds bio-oil and aliphatic and aromatic hydrocarbons in coconut fiber bio-oil, whereas guaiacols were the predominant components of the sugar cane straw bio-oil.展开更多
Multiple sulfur isotopes （32S, 335, 345, 365） and oxygen isotopes （160, 180） in Beijing aerosols were measured with MAT-253 isotope mass spectrometer. The δ345 values of Beijing aerosol samples range from 1.68%o ...Multiple sulfur isotopes （32S, 335, 345, 365） and oxygen isotopes （160, 180） in Beijing aerosols were measured with MAT-253 isotope mass spectrometer. The δ345 values of Beijing aerosol samples range from 1.68%o to 12.57%o with an average value of 5.86%0, indicating that the major sulfur source is from direct emission during coal combustion. The c5180 values vary from -5.29%0 to 9.02%0 with an average value of 5.17%o, revealing that the sulfate in Beijing aerosols is mainly composed of the secondary sulfate. The main heterogeneous oxidation of SO2 in atmosphere is related to H202 in July and August, whereas H202 oxidation and Fe3＋ catalytic oxidation with SO2 exist simultaneously in September and October. Remarkable sulfur iso- tope mass-independent fractionation effect is found in Beijing aerosols, which is commonly attributed to the photochemical oxidation of SO2 in the stratosphere. In addition, thermochemical reactions of sulfur-bearing compounds might be also a source of sulfur isotope anomalies based on the correlation between A335 and CAPE.展开更多
Fully inactivating SARS-Co V-2, the virus causing coronavirus disease 2019, is of key importance for interrupting virus transmission but is currently performed by using biologically or environmentally hazardous disinf...Fully inactivating SARS-Co V-2, the virus causing coronavirus disease 2019, is of key importance for interrupting virus transmission but is currently performed by using biologically or environmentally hazardous disinfectants. Herein, we report an eco-friendly and efficient electrochemical strategy for inactivating the SARS-Co V-2 using in-situ formed nickel oxide hydroxide as anode catalyst and sodium carbonate as electrolyte. At a voltage of 5 V, the SARS-Co V-2 viruses can be rapidly inactivated with disinfection efficiency reaching 95% in only 30 s and 99.99% in 5 min. Mass spectrometry analysis and theoretical calculations indicate that the reactive oxygen species generated on the anode can oxidize the peptide chains and induce cleavage of the peptide backbone of the receptor binding domain of the SARS-Co V-2 spike glycoprotein, and thereby disables the virus. This strategy provides a sustainable and highly efficient approach for the disinfection of the SARS-CoV-2 viruliferous aerosols and wastewater.展开更多
文摘The optical stability of chiral 2-hydroxy-2-phenylacetic acid in electron ionization mass spectrometry(EIMS) process has been detected directly by deuterium labelling technique. From the EI mass spectrum of deuterated 2-hydroxy-2-phenylacetic acid, the major characteristic fragment ion at m/z 108(the capture of the carbonyl group) and the corresponding isotopic ion(13C) at m/z 109 can be observed, and the ratio of m/z=109 to m/z=108 is about 8%(the calculated value is 7.8%). As enolization of deuterated 2-hydroxy-2-phenylacetic acid in mass spectrometry can yield the characteristic fragment ion at m/z 109 and results in much higher ratio of 109/108 than 8%; this study shows that no enolization takes place during the EI-MS process of 2-hydroxy-2-phenylacetic acid. This results can be concluded that these compounds are optically stable in the process of instantaneous vaporization at high temperature and electron impact ionization.
文摘[ Objective ] The aim of the research was to study the expression profile changes of genes involved in lipid metabolism pathway during liver regeneration in mice. [ Method] The CCI4 induced mouse model of liver regeneration was established and the total RNA was isolated from liver tissue of mouse. Then the changes of genes involved in lipid metabolism pathway during different stages of liver regeneration were detected through micro-array chip gene technique and their specific functions were also analyzed. [ Result] Dudng the process of liver regeneration, the expression level of 98 genes involved in lipid metabolism pathway changed, which were divided into eight groups according to change trend. In the mass, the expression of genes was inhibited in the early stage and up-regulated in the late phase. And the gene expression associated with fatty acid synthesis pathway was mainly up-regulated while the catabolic pathway did not change significantly. Most of genes involved in bile acid synthesis pathway were suppressed before 4.5 d and up-regulated after 4.5 d or 7 d. [ Conclusion] During the process of liver regeneration, the genes associated with lipid metabolism are expressed in different trends, and this data should provide a specific range of genes for further studying the regulation effect of lipid metabolism related pathway on liver regeneration.
基金Project(50101007) supported by the National Science Natural Foundation of China
文摘The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fluoride film on EN deposition were studied additionally.The results show that the fluoride film on magnesium alloys is a kind of porous film composed of MgF2 with thickness of 1.6-3.2 μm.The composition of the activation bath and pretreatment of EN processing have influence on the composition of the fluoride film.The fluoride is stable and dissolves little in EN bath;as a result,the fluoride film can protect magnesium substrate from the corrosion of EN bath.The composition of fluoride determines the initial deposition of EN and part of the fluoride film finally exists as inclusion in EN coating.
基金Supported by the National Natural Science Foundation of China （20876078, 21176124）, the National High Technology Research and Development Program of China （2011AA02A207）, the National Basic Research Program of China （2009CB724700）, the Key Program of the National Natural Science Foundation of China （20936002）, and the Independent Innovation Project of Jiangsu Province （CX（11）2051）.
文摘Lignins were isolated and purified from alkali treated prehydrolysate of corn stover. The paper presents the structural features of lignins in a series purification processes. Fourier transform infrared spectroscopy, ultraviolet-vis spectroscopy and proton nuclear magnetic resonance spectroscopy were used to analyze the chemical structure. Thermogravimetric analysis was applied to follow the thermal degradation, and wet chemical method was used to determine the sugar content. The results showed that the crude lignin from the prehydrolysate of corn stover was a heterogeneous material of syringyl, guaiacyl and p-hydroxyphenyl units, containing associated polysaccharides, lipids, and melted salts. Some of the crude lignin was chemically linked to hemicelluloses （mainly xylan）. The lipids in crude lignin were probably composed of saturated and/or unsaturated long carbon chains, fatty acids, tdterpenols, waxes, and derivatives of aromatic. The sugar content of purified lignin was less than 2.11%, mainly composed of guaiacyl units. DTGmax of purified lignin was 359 ℃. The majority of the hydroxyl groups were phenolic hydroxyl groups. The main type of linkages in purified lignin was β-O-4. Other types of linkages included β-5, β-β and α-O-4.
文摘Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of generating a class of substances of interest for fine chemistry （ketones, aldehydes, alcohols, phenols, etc.）. From biomass, it is possible to produce bio-oil using pyrolysis, a thermodegradation process. The quality of the bio-oil depends on the process conditions （pyrolysis temperature, heating temperature, etc.） and biomass used. In this paper, the pyrolysis （using a fixed bed reactor） of three biomasses （coconut fiber, coffee grounds and sugar cane straw） is studied. The results indicated that the bio-oil yields for all biomass were similar, approximately 37%. The chemical profile obtained by gas chromatography coupled with mass spectrometry （GC/qMS） showed high amounts of fatty acids in the coffee grounds bio-oil and aliphatic and aromatic hydrocarbons in coconut fiber bio-oil, whereas guaiacols were the predominant components of the sugar cane straw bio-oil.
基金supported by National Natural Science Foundation of China(Grant Nos.41240025 and 41373023)Start-up Foundation of the Ministry of Education for Overseas Returnees(Grant No.2012s001)Prospective Researching Project of Industry-University-Research of Jiangsu Province(Grant No.BY2013007-03)
文摘Multiple sulfur isotopes （32S, 335, 345, 365） and oxygen isotopes （160, 180） in Beijing aerosols were measured with MAT-253 isotope mass spectrometer. The δ345 values of Beijing aerosol samples range from 1.68%o to 12.57%o with an average value of 5.86%0, indicating that the major sulfur source is from direct emission during coal combustion. The c5180 values vary from -5.29%0 to 9.02%0 with an average value of 5.17%o, revealing that the sulfate in Beijing aerosols is mainly composed of the secondary sulfate. The main heterogeneous oxidation of SO2 in atmosphere is related to H202 in July and August, whereas H202 oxidation and Fe3＋ catalytic oxidation with SO2 exist simultaneously in September and October. Remarkable sulfur iso- tope mass-independent fractionation effect is found in Beijing aerosols, which is commonly attributed to the photochemical oxidation of SO2 in the stratosphere. In addition, thermochemical reactions of sulfur-bearing compounds might be also a source of sulfur isotope anomalies based on the correlation between A335 and CAPE.
基金supported by the National Natural Science Foundation of China(21890753,21988101 to Dehui Deng,91853101 to Fangjun Wang,and 91845106 to Liang Yu)the Strategic PriorityResearch Program of the Chinese Academy of Sciences(XDB36030200 to Dehui Deng)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y201936 to Dehui Deng,Y201750 to Yangbo Hu)。
文摘Fully inactivating SARS-Co V-2, the virus causing coronavirus disease 2019, is of key importance for interrupting virus transmission but is currently performed by using biologically or environmentally hazardous disinfectants. Herein, we report an eco-friendly and efficient electrochemical strategy for inactivating the SARS-Co V-2 using in-situ formed nickel oxide hydroxide as anode catalyst and sodium carbonate as electrolyte. At a voltage of 5 V, the SARS-Co V-2 viruses can be rapidly inactivated with disinfection efficiency reaching 95% in only 30 s and 99.99% in 5 min. Mass spectrometry analysis and theoretical calculations indicate that the reactive oxygen species generated on the anode can oxidize the peptide chains and induce cleavage of the peptide backbone of the receptor binding domain of the SARS-Co V-2 spike glycoprotein, and thereby disables the virus. This strategy provides a sustainable and highly efficient approach for the disinfection of the SARS-CoV-2 viruliferous aerosols and wastewater.
