Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissue...Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.展开更多
双极板是氢燃料电池的重要部件之一,钛作为金属双极板基材有诸多优势,但钛的成形性能差、回弹较为严重,本文以0.1 mm TA2纯钛薄板微流道液压成形为研究对象,通过试验和有限元模拟相结合的方法研究纯钛微结构变形行为,分析工艺参数对微...双极板是氢燃料电池的重要部件之一,钛作为金属双极板基材有诸多优势,但钛的成形性能差、回弹较为严重,本文以0.1 mm TA2纯钛薄板微流道液压成形为研究对象,通过试验和有限元模拟相结合的方法研究纯钛微结构变形行为,分析工艺参数对微流道成形质量的影响规律,为液压成形钛双极板提供参考。建立了TA2纯钛薄板微流道液压成形的有限元模型,通过与试验件的轮廓及厚度分布验证有限元模型的准确性;研究了液体压力、加载速率和脉动加载对微流道成形的影响。结果表明,微流道液压成形过程中材料应变路径为平面应变,且上圆角位置最容易破裂;加载速率对微流道成形影响不大,随着加载速率的提高,成形深度略有下降,但是变化不大,仅有3%;脉动加载路径能够提高材料的流动变形能力,在均为临界破裂情况下,相比较线性加载路径成形深度有较高的提高,可达232.2μm,提高幅度为23%。展开更多
This paper attempts to understand the Pt-like catalytic activity of transition metal carbide Ta4C_(3) for IRR(I_(3)^(-)reduction reaction)based on the correlation of adsorption energy to d-band center(εd).Ta4C_(3) wa...This paper attempts to understand the Pt-like catalytic activity of transition metal carbide Ta4C_(3) for IRR(I_(3)^(-)reduction reaction)based on the correlation of adsorption energy to d-band center(εd).Ta4C_(3) was prepared by carbothermal reduction method with a template.Its photoelectrochemical properties were investigated as a CE(counter electrode)in DSSC(dye-sensitized solar cell).Its surface electronic structures,including DOS(density of state)andεd,and adsorption energy were computed by first-principle DFT(density functional theory).In TMC(transition metal carbide)Ta4C_(3),the interaction between Ta and C atoms makes the d-band of Ta broaden and results in the downward shift of itsεd.A moderate absorption energy corresponding to theεd is achieved,which is the nature of the Pt-like catalytic activity of Ta4C_(3).Appropriate change of adsorption energy by adjustingεd is a promising strategy to improve catalytic activity.This work is of great significance to the fundamental and application researches.展开更多
基金Shanghai Science and Technology Commission“R&D Public Service Platform and Institutional Capacity Improvement Project”,Grant/Award Number:21DZ2291300National Science and Technology Major Project,Grant/Award Number:2017ZX10304402-001-006 and 2017ZX10304402-001-012Start-on Funding from Shanghai Public Health Clinical Center,Grant/Award Number:KY-GW-2019-11,KYGW-2019-19 and KY-GW-2021-39。
文摘Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.
文摘双极板是氢燃料电池的重要部件之一,钛作为金属双极板基材有诸多优势,但钛的成形性能差、回弹较为严重,本文以0.1 mm TA2纯钛薄板微流道液压成形为研究对象,通过试验和有限元模拟相结合的方法研究纯钛微结构变形行为,分析工艺参数对微流道成形质量的影响规律,为液压成形钛双极板提供参考。建立了TA2纯钛薄板微流道液压成形的有限元模型,通过与试验件的轮廓及厚度分布验证有限元模型的准确性;研究了液体压力、加载速率和脉动加载对微流道成形的影响。结果表明,微流道液压成形过程中材料应变路径为平面应变,且上圆角位置最容易破裂;加载速率对微流道成形影响不大,随着加载速率的提高,成形深度略有下降,但是变化不大,仅有3%;脉动加载路径能够提高材料的流动变形能力,在均为临界破裂情况下,相比较线性加载路径成形深度有较高的提高,可达232.2μm,提高幅度为23%。
基金Financial support for this work was provided by Key Research and Development Projects of Shanxi Province(201703D121023).
文摘This paper attempts to understand the Pt-like catalytic activity of transition metal carbide Ta4C_(3) for IRR(I_(3)^(-)reduction reaction)based on the correlation of adsorption energy to d-band center(εd).Ta4C_(3) was prepared by carbothermal reduction method with a template.Its photoelectrochemical properties were investigated as a CE(counter electrode)in DSSC(dye-sensitized solar cell).Its surface electronic structures,including DOS(density of state)andεd,and adsorption energy were computed by first-principle DFT(density functional theory).In TMC(transition metal carbide)Ta4C_(3),the interaction between Ta and C atoms makes the d-band of Ta broaden and results in the downward shift of itsεd.A moderate absorption energy corresponding to theεd is achieved,which is the nature of the Pt-like catalytic activity of Ta4C_(3).Appropriate change of adsorption energy by adjustingεd is a promising strategy to improve catalytic activity.This work is of great significance to the fundamental and application researches.
基金supported by the National Key Research and Development Program of China(No.2018YFA0707300)the National Natural Science Foundation of China(Nos.51901151,51905372,52275362,52171122)China Postdoctoral Science Foundation(Nos.2020M680918,2021T140503)。
