AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay con...AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.展开更多
Formate (HCOO-), acetate (CH3COO-), oxalate (C2O42-) and pyruvate ((CO)C2O42-) are detected in a 14.08-m-long ice core recovered in Glacier 1 at the Urumqi riverhead, Tianshan, China, which is a mid-latitude alpine gl...Formate (HCOO-), acetate (CH3COO-), oxalate (C2O42-) and pyruvate ((CO)C2O42-) are detected in a 14.08-m-long ice core recovered in Glacier 1 at the Urumqi riverhead, Tianshan, China, which is a mid-latitude alpine glacier (43°06′N, 86°49′E). the mean concentrations for the four organic acids in recent four decades are (102.8±147.3), (392.3±390.8), (6.9(+14.8) and (4.2±8.3) ng/g, respectively, with the ratio for HCOO-/CH3COO- of 0.34± 0.43. They represent the major acid components, and originate mainly from anthropogenic emission in the nearby industrial cities. Compared with Greenland and Antarctica, Glacier 1 is much higher in carboxylic acids, which were not subjected to long distance transportation as well as complicated atmospheric reactions. The alpine glacier can be, therefore, useful to reconstructing human pollution scenario to the regional atmosphere.展开更多
Direct formic acid fuel cells （DFAFCs） allow highly efficient low temperature conversion of chemical energy into electricity and are expected to play a vital role in our future sustainable society. However, the mass...Direct formic acid fuel cells （DFAFCs） allow highly efficient low temperature conversion of chemical energy into electricity and are expected to play a vital role in our future sustainable society. However, the massive precious metal usage in current membrane electrode assembly （MEA） technology greatly inhibits their actual applications. Here we demonstrate a new type of anode constructed by confining highly active nanoengineered catalysts into an ultra-thin catalyst layer with thickness around 100 nm. Specifically, an atomic layer of platinum is first deposited onto nanoporous gold （NPG） leaf to achieve high utilization of Pt and easy accessibility of both reactants and electrons to active sites. These NPG-Pt core/shell nanostructures are further decorated by a sub-monolayer of Bi to create highly active reaction sites for formic acid electro-oxidation. Thus obtained layer-structured NPG-Pt-Bi thin films allow a dramatic decrease in Pt usage down to 3 ~tg.cm-2, while maintaining very high electrode activity and power performance at sufficiently low overall precious metal loading. Moreover, these electrode materials show superior durability during half-year test in actual DFAFCs, with remarkable resistance to common impurities in formic acid, which together imply their great potential in applications in actual devices.展开更多
Gadolinium(Ⅲ)-based T_(1) contrast agents have been widely used in clinical MRI.In this study,salicylic acid-gadolinium chelate was prepared via directly coordination reaction of gadolinium ion and salicylic acid.The...Gadolinium(Ⅲ)-based T_(1) contrast agents have been widely used in clinical MRI.In this study,salicylic acid-gadolinium chelate was prepared via directly coordination reaction of gadolinium ion and salicylic acid.Then,three polyethylene glycols with different molecular weight were modified on the surface of salicylic acid-gadolinium by simple chemical coupling to construct three core-shell structural Gd based composites.The scanning electron microscopy(SEM)and transmission electron microscopy(TEM)characterization results show that the composite is a spherical particle with a diameter of about 100-200 nm.The longitudinal relaxation rate r_(1) of the Gal-PEG-2000 is 11.097(mmol/L)^(-1)/s,and the ratio of r_(2)/r_(1) is as low as 2.53.The composite shows good liver and intestines MRI performances after being used in in vivo imaging,showing a good prospect of biological application.展开更多
Carbon dots(CDs)have uniquely structural,physicochemical and photochemical properties,suggesting a promising platform for catalysis applications.The in-depth understanding of the structure-activity relationship in the...Carbon dots(CDs)have uniquely structural,physicochemical and photochemical properties,suggesting a promising platform for catalysis applications.The in-depth understanding of the structure-activity relationship in the CDs-based catalyst system needs to know the effect of the crystalline core on their catalytic performance.The efficient catalytic oxidation of cyclohexane is an urgent challenge in current chemical industry,in which,adipic acid(AA)plays an important role in industry for synthesis of nylon6 and nylon-66.Here,we fabricated the pristine CDs by electrochemical etching graphite rod method and derived CDs with high crystalline core(CD-600,CD-800,and CD-1100)through a thermal treatment method in tube furnace.Furthermore,these CDs performed an outstanding catalytic performance for one-step synthesis of AA from cyclohexane.With the help of machine learning(ML),the deep correlations between features(structures of CDs,catalytic conditions)and catalytic performances were investigated by XGBoost(XGB)model.Then under the optimization and prediction of XGB,it was found that high crystalline core preceded the other features and CD-1100 could get the best conversion of 30.696%and selectivity to AA of 92.52%at reaction conditions of 130℃,1.5 MPa,and 10 h.This work pioneered the application of ML in industrial issues and demonstrated a comprehensive understanding on CDs as catalyst to realize one-step synthesis of AA.展开更多
基金This work is supported by the National Natural Science Foundation of China (Nos.21133001 and 21303004),and the National Basic Research Program of China (Nos.2013CB932601 and 2014CB239303).
基金the National Nature Science Foundation of China,No.39800121
文摘AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.
基金This study was jointly supported by the National Natural Science Foundation of China (Grant No. 49871022) the Chinese Academy of Sciences (Grant No. KZ951-A1-402-03)llTianshan Gla-ciological Station and the Chinese Postdoctoral Research Foundation.
文摘Formate (HCOO-), acetate (CH3COO-), oxalate (C2O42-) and pyruvate ((CO)C2O42-) are detected in a 14.08-m-long ice core recovered in Glacier 1 at the Urumqi riverhead, Tianshan, China, which is a mid-latitude alpine glacier (43°06′N, 86°49′E). the mean concentrations for the four organic acids in recent four decades are (102.8±147.3), (392.3±390.8), (6.9(+14.8) and (4.2±8.3) ng/g, respectively, with the ratio for HCOO-/CH3COO- of 0.34± 0.43. They represent the major acid components, and originate mainly from anthropogenic emission in the nearby industrial cities. Compared with Greenland and Antarctica, Glacier 1 is much higher in carboxylic acids, which were not subjected to long distance transportation as well as complicated atmospheric reactions. The alpine glacier can be, therefore, useful to reconstructing human pollution scenario to the regional atmosphere.
文摘Direct formic acid fuel cells （DFAFCs） allow highly efficient low temperature conversion of chemical energy into electricity and are expected to play a vital role in our future sustainable society. However, the massive precious metal usage in current membrane electrode assembly （MEA） technology greatly inhibits their actual applications. Here we demonstrate a new type of anode constructed by confining highly active nanoengineered catalysts into an ultra-thin catalyst layer with thickness around 100 nm. Specifically, an atomic layer of platinum is first deposited onto nanoporous gold （NPG） leaf to achieve high utilization of Pt and easy accessibility of both reactants and electrons to active sites. These NPG-Pt core/shell nanostructures are further decorated by a sub-monolayer of Bi to create highly active reaction sites for formic acid electro-oxidation. Thus obtained layer-structured NPG-Pt-Bi thin films allow a dramatic decrease in Pt usage down to 3 ~tg.cm-2, while maintaining very high electrode activity and power performance at sufficiently low overall precious metal loading. Moreover, these electrode materials show superior durability during half-year test in actual DFAFCs, with remarkable resistance to common impurities in formic acid, which together imply their great potential in applications in actual devices.
基金Project supported by the Natural Science Foundation of Gansu Province(20JR10RA511,2019B-084)。
文摘Gadolinium(Ⅲ)-based T_(1) contrast agents have been widely used in clinical MRI.In this study,salicylic acid-gadolinium chelate was prepared via directly coordination reaction of gadolinium ion and salicylic acid.Then,three polyethylene glycols with different molecular weight were modified on the surface of salicylic acid-gadolinium by simple chemical coupling to construct three core-shell structural Gd based composites.The scanning electron microscopy(SEM)and transmission electron microscopy(TEM)characterization results show that the composite is a spherical particle with a diameter of about 100-200 nm.The longitudinal relaxation rate r_(1) of the Gal-PEG-2000 is 11.097(mmol/L)^(-1)/s,and the ratio of r_(2)/r_(1) is as low as 2.53.The composite shows good liver and intestines MRI performances after being used in in vivo imaging,showing a good prospect of biological application.
基金the National Key R&D Program of China(Nos.2020YFA0406103,2020YFA0406104,and 2020YFA0406101)National MCF Energy R&D Program of China(No.2018YFE0306105)+4 种基金Innovative Research Group Project of the National Natural Science Foundation of China(No.51821002)the National Natural Science Foundation of China(Nos.51725204,21771132,51972216,and 52041202)the Natural Science Foundation of Jiangsu Province(No.BK20190041)KeyArea Research and Development Program of GuangDong Province(No.2019B010933001)Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project,and Suzhou Key Laboratory of Functional Nano&Soft Materials.
文摘Carbon dots(CDs)have uniquely structural,physicochemical and photochemical properties,suggesting a promising platform for catalysis applications.The in-depth understanding of the structure-activity relationship in the CDs-based catalyst system needs to know the effect of the crystalline core on their catalytic performance.The efficient catalytic oxidation of cyclohexane is an urgent challenge in current chemical industry,in which,adipic acid(AA)plays an important role in industry for synthesis of nylon6 and nylon-66.Here,we fabricated the pristine CDs by electrochemical etching graphite rod method and derived CDs with high crystalline core(CD-600,CD-800,and CD-1100)through a thermal treatment method in tube furnace.Furthermore,these CDs performed an outstanding catalytic performance for one-step synthesis of AA from cyclohexane.With the help of machine learning(ML),the deep correlations between features(structures of CDs,catalytic conditions)and catalytic performances were investigated by XGBoost(XGB)model.Then under the optimization and prediction of XGB,it was found that high crystalline core preceded the other features and CD-1100 could get the best conversion of 30.696%and selectivity to AA of 92.52%at reaction conditions of 130℃,1.5 MPa,and 10 h.This work pioneered the application of ML in industrial issues and demonstrated a comprehensive understanding on CDs as catalyst to realize one-step synthesis of AA.
