Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding ...Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, 13, and Ti. The thermal conductivity （TC） oh- mined exhibited as high as 688 W.m-1.K-1, but also as low as 325 W.m-1.K-l. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.展开更多
Vanadium-catalyzed oxidative kinetic resolution（OKR） of methyl o-chloromandelate 2a,key intermediate of the well-known oral antiplatelet agent（S）-clopidogrel,was achieved by ambient air for the first time.The air ...Vanadium-catalyzed oxidative kinetic resolution（OKR） of methyl o-chloromandelate 2a,key intermediate of the well-known oral antiplatelet agent（S）-clopidogrel,was achieved by ambient air for the first time.The air oxidation system,which was composed of vanadium and tridentate Schiff base ligands derived from amino alcohols and salicylaldehyde derivatives,afforded an efficient and economic approach to the target intermediate with high enantioselectivities（99%ee）.展开更多
Sciff bases 1 and 2, .which were derived from chiral aminoalcohols, were used as figands in Ti-catalyzed asymmetric alkynylation of aldehydes. Good enantioselectivities （up to 88% ee） and high chemical yields （80-...Sciff bases 1 and 2, .which were derived from chiral aminoalcohols, were used as figands in Ti-catalyzed asymmetric alkynylation of aldehydes. Good enantioselectivities （up to 88% ee） and high chemical yields （80-90%） were obtained.展开更多
Apoptosis and necroptosis are two types of programmed cell death with distinct morphological features.Necroptosis has been assumed to be more inflammatory than apoptosis,but a recent paper1 concluded that necroptotic ...Apoptosis and necroptosis are two types of programmed cell death with distinct morphological features.Necroptosis has been assumed to be more inflammatory than apoptosis,but a recent paper1 concluded that necroptotic cells cannot elicit cross-priming of CD8^(+)T cells and that NF-κB activation in necroptotic cells is required for maximal CD8^(+)T-cell cross-priming.展开更多
CD8^(+)T cells play a central role in antiviral immune responses.Upon infection,naive CD8^(+)T cells differentiate into effector cells to eliminate virus-infected cells,and some of these effector cells further differe...CD8^(+)T cells play a central role in antiviral immune responses.Upon infection,naive CD8^(+)T cells differentiate into effector cells to eliminate virus-infected cells,and some of these effector cells further differentiate into memory cells to provide long-term protection after infection is resolved.Although extensively investigated,the underlying mechanisms of CD+T-cell differentiation remain incompletely understood.Themis is a T-cell-specific protein that plays critical roles in T-cell development.Recent studies using Themis T-cell conditional knockout mice also demonstrated that Themis is required to promote mature CD8^(+)T-cell homeostasis,cytokine responsiveness,and antibacterial responses.In this study,we used LCMV Armstrong infection as a probe to explore the role of Themis in viral infection.We found that preexisting CD8^(+)T-cell homeostasis defects and cytokine hyporesponsiveness do not impair viral clearance in Themis T-cell conditional knockout mice.Further analyses showed that in the primary immune response,Themis deficiency promoted the differentiation of CD8^(+)effector cells and increased their TNF and IFNy production.Moreover,Themis deficiency impaired memory precursor cell(MPEC)differentiation but promoted short-lived effector cell(SLEC)differentiation.Themis deficiency also enhanced effector cytokine production in memory CD8^(+)T cells while impairing central memory CD8^(+)T-cell formation.Mechanistically,we found that Themis mediates PD-1 expression and its signaling in effector CD8^(+)T cells,which explains the elevated cytokine production in these cells when Themis is disrupted.展开更多
基金supported by the National Natural Science Foundation of China (No.50971020) National High-Tech Research and Development Program of China (No.2008AA03Z505)
文摘Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, 13, and Ti. The thermal conductivity （TC） oh- mined exhibited as high as 688 W.m-1.K-1, but also as low as 325 W.m-1.K-l. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.
基金supported by National Natural Science Foundation of China(No.20472116) and 2009 intranational visiting doctoral student project of Ministry of Education.
文摘Vanadium-catalyzed oxidative kinetic resolution（OKR） of methyl o-chloromandelate 2a,key intermediate of the well-known oral antiplatelet agent（S）-clopidogrel,was achieved by ambient air for the first time.The air oxidation system,which was composed of vanadium and tridentate Schiff base ligands derived from amino alcohols and salicylaldehyde derivatives,afforded an efficient and economic approach to the target intermediate with high enantioselectivities（99%ee）.
基金This study is supported by the National Natural Science Foundation of China(No.20472116)the Natural Science Foundation of Liaoning Province(No.1050155)Shenyang Pharmaceutical University Fund.
文摘Sciff bases 1 and 2, .which were derived from chiral aminoalcohols, were used as figands in Ti-catalyzed asymmetric alkynylation of aldehydes. Good enantioselectivities （up to 88% ee） and high chemical yields （80-90%） were obtained.
基金supported by the National Natural Science Foundation of China(91029304,31420103910,31330047 and 81630042)the National Basic Research Program of China(973 Program,2015CB553800,2013CB944903 and 2014CB541804)+1 种基金the 111 Project(B12001)the National Science Foundation of China for Fostering Talents in Basic Research(J1310027).
文摘Apoptosis and necroptosis are two types of programmed cell death with distinct morphological features.Necroptosis has been assumed to be more inflammatory than apoptosis,but a recent paper1 concluded that necroptotic cells cannot elicit cross-priming of CD8^(+)T cells and that NF-κB activation in necroptotic cells is required for maximal CD8^(+)T-cell cross-priming.
基金the Core Facility of Biomedical Sciences,Xiamen University for Flow Cytometry Cell Sorting service.This study was supported by the National Natural Science Foundation of China(32070887)the Fundamental Research Funds for the Central Universities(20720220003)to G.F.Singapore Ministry of Education(MOE-000112)Singapore Ministry of Health's National Medical Research Council(MOH-000523)to N.RJ.Gascoigne.The Natural Science Foundation of Fujian Province(No.2019J01009)to Q.L.The National Natural Science Foundation of China(U1904206)to X.L.C.The funders had no role in the study design,data collection and analysis,decision to publish,or preparation of the manuscript。
文摘CD8^(+)T cells play a central role in antiviral immune responses.Upon infection,naive CD8^(+)T cells differentiate into effector cells to eliminate virus-infected cells,and some of these effector cells further differentiate into memory cells to provide long-term protection after infection is resolved.Although extensively investigated,the underlying mechanisms of CD+T-cell differentiation remain incompletely understood.Themis is a T-cell-specific protein that plays critical roles in T-cell development.Recent studies using Themis T-cell conditional knockout mice also demonstrated that Themis is required to promote mature CD8^(+)T-cell homeostasis,cytokine responsiveness,and antibacterial responses.In this study,we used LCMV Armstrong infection as a probe to explore the role of Themis in viral infection.We found that preexisting CD8^(+)T-cell homeostasis defects and cytokine hyporesponsiveness do not impair viral clearance in Themis T-cell conditional knockout mice.Further analyses showed that in the primary immune response,Themis deficiency promoted the differentiation of CD8^(+)effector cells and increased their TNF and IFNy production.Moreover,Themis deficiency impaired memory precursor cell(MPEC)differentiation but promoted short-lived effector cell(SLEC)differentiation.Themis deficiency also enhanced effector cytokine production in memory CD8^(+)T cells while impairing central memory CD8^(+)T-cell formation.Mechanistically,we found that Themis mediates PD-1 expression and its signaling in effector CD8^(+)T cells,which explains the elevated cytokine production in these cells when Themis is disrupted.
