A highly efficient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids, malononitrile and ethyl ac...A highly efficient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids, malononitrile and ethyl acetoacetate using nano silica supported tin （II） chloride as a catalyst. In this method SnCl2/nano Si02 was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.展开更多
With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established...With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established,featuring readily available starting materials,high efficiency,good functional groups compatibility,green chemistry with high atom economy and only water release,etc.,to provide a series of polyfunctionalized 5-alkenyl-3-carbonylfurans,which could be applied to the late-stage functionalization of naturally occurring compounds and bioactive molecules,as well as the transformation to pyrroles and polycyclic aromatic hydrocarbon via electrocyclic reaction.Theγ-hydroxyl has played an important role in the unexpected process of ring opening isomerization of 2H-pyran to furanones,as confirmed by detailed mechanistic studies.展开更多
Objectives: The definition of CD8+ T cell attributes that mediate protective immunity in HIV dis-ease progression has not been clearly defined. Although our ability to characterize these cells continues to improve, th...Objectives: The definition of CD8+ T cell attributes that mediate protective immunity in HIV dis-ease progression has not been clearly defined. Although our ability to characterize these cells continues to improve, the extent to which specific memory phenotypic categories of CD8+ T cells reliably represent their functional attributes remains controversial. Methods: We simultaneously assessed surface phenotype and functionality of HIV-specific CD8+ T cells by multiparametric flow cytometry, measuring five CD8+ T cell functions (CD107a, IFNγ, MIP-1β, TNFα and IL2) and phenotypic markers CCR7, CD45RA, and CD27, in parallel in 24 HIV-infected individuals. Results: Virus-specific responses were contained within all eight phenotypic categories defined using CCR7, CD45RA, and CD27. Phenotypic profiles of HIV-specific cells differed from CEF-specific cells, with HIV-specific cells having higher levels of CD45RA (p = 0.008). Interestingly a large portion of CEF and HIV-specific cells were found within previously undefined phenotypes CCR7+CD27-CD45RA+ (14.6% and 17.2%, respectively) and CCR7+CD27-CD45RA-(14.8% and 15.8%, respectively). In addition, up to 10% - 20% of responding cells were phenotypically “naive”. Additionally, memory phenotypes of cells exhibiting monofunctional and polyfunctional responses frequently differed, and failed to associate with a consistent phenotype representing functionally active cells. Conclusion: These data suggest that particularly after antigen stimulation, that surface phenotypes defined by CCR7, CD27 and CD45RA expression on antigen-specific CD8+ T cells, reflect a wide range of immunological functions, and that no single phenotype defined by memory marker expression can reliably be used to identify functional capacity.展开更多
基金University of Kashan for supporting this work by Grant No.159196/XV
文摘A highly efficient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids, malononitrile and ethyl acetoacetate using nano silica supported tin （II） chloride as a catalyst. In this method SnCl2/nano Si02 was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.
基金Financial support from National Natural Science Foundation of China(Grant No.22201187)the starting grant from Capital Medical University(Grant No.3100-12400123)。
文摘With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established,featuring readily available starting materials,high efficiency,good functional groups compatibility,green chemistry with high atom economy and only water release,etc.,to provide a series of polyfunctionalized 5-alkenyl-3-carbonylfurans,which could be applied to the late-stage functionalization of naturally occurring compounds and bioactive molecules,as well as the transformation to pyrroles and polycyclic aromatic hydrocarbon via electrocyclic reaction.Theγ-hydroxyl has played an important role in the unexpected process of ring opening isomerization of 2H-pyran to furanones,as confirmed by detailed mechanistic studies.
文摘Objectives: The definition of CD8+ T cell attributes that mediate protective immunity in HIV dis-ease progression has not been clearly defined. Although our ability to characterize these cells continues to improve, the extent to which specific memory phenotypic categories of CD8+ T cells reliably represent their functional attributes remains controversial. Methods: We simultaneously assessed surface phenotype and functionality of HIV-specific CD8+ T cells by multiparametric flow cytometry, measuring five CD8+ T cell functions (CD107a, IFNγ, MIP-1β, TNFα and IL2) and phenotypic markers CCR7, CD45RA, and CD27, in parallel in 24 HIV-infected individuals. Results: Virus-specific responses were contained within all eight phenotypic categories defined using CCR7, CD45RA, and CD27. Phenotypic profiles of HIV-specific cells differed from CEF-specific cells, with HIV-specific cells having higher levels of CD45RA (p = 0.008). Interestingly a large portion of CEF and HIV-specific cells were found within previously undefined phenotypes CCR7+CD27-CD45RA+ (14.6% and 17.2%, respectively) and CCR7+CD27-CD45RA-(14.8% and 15.8%, respectively). In addition, up to 10% - 20% of responding cells were phenotypically “naive”. Additionally, memory phenotypes of cells exhibiting monofunctional and polyfunctional responses frequently differed, and failed to associate with a consistent phenotype representing functionally active cells. Conclusion: These data suggest that particularly after antigen stimulation, that surface phenotypes defined by CCR7, CD27 and CD45RA expression on antigen-specific CD8+ T cells, reflect a wide range of immunological functions, and that no single phenotype defined by memory marker expression can reliably be used to identify functional capacity.
