为应对3He短缺情况,采用更加低价、易获取的液闪来探测中子,并推广应用中子多重性技术,研制了一种基于EJ309的液闪快中子探测器,自主开发了中子伽玛甄别电路,采用电荷积分法进行中子伽玛信号甄别,并通过实验验证了该中子探测器在能量阈...为应对3He短缺情况,采用更加低价、易获取的液闪来探测中子,并推广应用中子多重性技术,研制了一种基于EJ309的液闪快中子探测器,自主开发了中子伽玛甄别电路,采用电荷积分法进行中子伽玛信号甄别,并通过实验验证了该中子探测器在能量阈值为100 keVee(ee—等效能)时,中子伽玛甄别性能参数FOM(Figure of Merit)大于1;在多重性数据分析过程中,为了解决散射中子对多重性符合计数带来的影响,引入散射串扰因子对传统多重性方程进行了修正;为降低测量腔内探测效率的非均匀性对测量结果的影响,通过蒙特卡洛模拟设计了一套球形快中子多重性测量装置,并通过实验验证了其探测效率的均匀性以及测量结果的相对偏差,结果表明:其探测效率的均匀性以及测量结果的相对偏差均好于5%,该工作为快中子多重性测量技术的实际应用奠定了基础。展开更多
当机体受到亲电子物质或活性氧刺激时,核转录相关因子2(nuclear factor erythroid-2 related factor 2,Nrf2)能诱导出一系列的保护性蛋白,从而抵抗内源性或外源性氧化应激造成的损害。越来越多的研究发现,某些组织比如心脏受到氧化应激...当机体受到亲电子物质或活性氧刺激时,核转录相关因子2(nuclear factor erythroid-2 related factor 2,Nrf2)能诱导出一系列的保护性蛋白,从而抵抗内源性或外源性氧化应激造成的损害。越来越多的研究发现,某些组织比如心脏受到氧化应激时,Nrf2的活性和线粒体生物合成有关。在Surfeit 1蛋白(Surfeit locus protein 1,Surf1)突变的小鼠心脏中发现,由于细胞色素C氧化酶的缺乏导致细胞呼吸减少从而激活Nrf2。本文从Kelch样环氧氯丙烷相关蛋白1(Kelch-like ECH-associated protein-1,Keap1)-Nrf2通路与线粒体的关系以及氧化应激条件下Nrf2信号通路与线粒体之间的信号交联为重点进行了综述。展开更多
The nuclear receptor superfamily and the transcriptional factors associated with cytokines are inherently different families of signaling molecules and activate gene transcription by binding to their respective respon...The nuclear receptor superfamily and the transcriptional factors associated with cytokines are inherently different families of signaling molecules and activate gene transcription by binding to their respective responsive element.However,it has become increasingly clear from our works and others that nuclear receptors are important regulators of cytokine production and function through complex and varied interactions between these distinct transcriptional factors.This review provides a general overview of the mechanism of action of nuclear receptors and their transcriptional crosstalk with transcriptional factors associated with cytokine transduction pathways.One of the most important mechanistic aspects is protein to protein interaction through a direct or co-regulator-mediated indirect manner.Such crosstalk is crucially involved in physiological and therapeutic roles of nuclear receptors and their iigands in immunity, inflammation and cytokine-related tumors.Cellular & Molecular Immunology.2004;1(6):416-424.展开更多
Although auxin and brassinosteroid （BR） synergistically control various plant responses, the molecular mechanism underlying the auxin-BR crosstalk is not wen understood. We previously identified SMOS1, an auxin-regu...Although auxin and brassinosteroid （BR） synergistically control various plant responses, the molecular mechanism underlying the auxin-BR crosstalk is not wen understood. We previously identified SMOS1, an auxin-regulated APETALA2-type transcription factor, as the causal gene of the small organ size 1 （smosl） mutant that is characterized by a decreased final size of various organs in rice. In this study, we identified another smos mutant, smos2, which shows the phenotype indistinguishable from smosl. SMOS2 was identical to the previously reported DWARF AND LOWoTILLERING （DLT）, which encodes a GRAS protein involved in BR signaling. SMOS1 and SMOS2/DLT physically interact to cooperatively enhance transcriptional transactivation activity in yeast and in rice nuclei. Consistently, the expression of OsPHI-1, a direct target of SMOS1, is upregulated only when SMOS1 and SMOS2/DLT proteins are both present in rice ceils. Taken together, our results suggest that SMOS1 and SMOS2/DLT form a keystone complex on auxin-BR signaling crosstalk in rice.展开更多
文摘为应对3He短缺情况,采用更加低价、易获取的液闪来探测中子,并推广应用中子多重性技术,研制了一种基于EJ309的液闪快中子探测器,自主开发了中子伽玛甄别电路,采用电荷积分法进行中子伽玛信号甄别,并通过实验验证了该中子探测器在能量阈值为100 keVee(ee—等效能)时,中子伽玛甄别性能参数FOM(Figure of Merit)大于1;在多重性数据分析过程中,为了解决散射中子对多重性符合计数带来的影响,引入散射串扰因子对传统多重性方程进行了修正;为降低测量腔内探测效率的非均匀性对测量结果的影响,通过蒙特卡洛模拟设计了一套球形快中子多重性测量装置,并通过实验验证了其探测效率的均匀性以及测量结果的相对偏差,结果表明:其探测效率的均匀性以及测量结果的相对偏差均好于5%,该工作为快中子多重性测量技术的实际应用奠定了基础。
文摘目的了解表皮生长因子受体(epidermal growth factor receptor,EGFR)和整合素信号通路在胃癌细胞SGC7901中的交叉反应和对细胞侵袭增殖的影响。方法使用EGF和Fn刺激SGC7901细胞,免疫沉淀和蛋白质电泳检测ERK、FAK和p130cas总蛋白和FAK Y397、p130cas Y410和ERK总酪氨酸磷酸化的改变;使用改良Boyden小室法检测胃癌细胞侵袭力;MTT法检测细胞增殖的改变;使用RNA干扰降低FAK表达,观察FAK低表达对交叉反应和胃癌侵袭增殖的影响。结果 ERK、FAK和p130cas总蛋白在刺激前后无变化(P>0.05)。Fn刺激后,ERK总酪氨酸磷酸化增强了2.90倍(P<0.05),细胞侵袭力增强了2.36倍(P<0.05),24 h MTT值升高了1.68倍(P<0.05);EGF刺激后,FAKY397磷酸化增强了2.75倍(P<0.05),p130cas Y410磷酸化增强了4.33倍(P<0.05),细胞侵袭力增强了1.50倍(P<0.05),24 h MTT值分别升高了1.76倍(P<0.05)。转染FAK siRNA组细胞,FAK Y397磷酸化表达只有对照组的0.30倍(P<0.05);Fn刺激后,ERK总磷酸化表达只有对照组的0.66倍(P<0.05),细胞侵袭力只有对照组的0.37倍(P<0.05),24 h MTT值只有对照组的0.63倍(P<0.05);EGF刺激后,p130 Y410磷酸化只有对照组的0.49倍(P<0.05),细胞侵袭力只有对照组的0.48倍(P<0.05),24 h MTT值只有对照组0.77倍(P<0.05)。结论 EGFR和整合素信号在胃癌细胞中发生交叉反应,FAK是其中的关键信号分子,阻断FAK表达可以有效抑制两条信号通路引起的胃癌细胞侵袭和增殖。
文摘当机体受到亲电子物质或活性氧刺激时,核转录相关因子2(nuclear factor erythroid-2 related factor 2,Nrf2)能诱导出一系列的保护性蛋白,从而抵抗内源性或外源性氧化应激造成的损害。越来越多的研究发现,某些组织比如心脏受到氧化应激时,Nrf2的活性和线粒体生物合成有关。在Surfeit 1蛋白(Surfeit locus protein 1,Surf1)突变的小鼠心脏中发现,由于细胞色素C氧化酶的缺乏导致细胞呼吸减少从而激活Nrf2。本文从Kelch样环氧氯丙烷相关蛋白1(Kelch-like ECH-associated protein-1,Keap1)-Nrf2通路与线粒体的关系以及氧化应激条件下Nrf2信号通路与线粒体之间的信号交联为重点进行了综述。
文摘The nuclear receptor superfamily and the transcriptional factors associated with cytokines are inherently different families of signaling molecules and activate gene transcription by binding to their respective responsive element.However,it has become increasingly clear from our works and others that nuclear receptors are important regulators of cytokine production and function through complex and varied interactions between these distinct transcriptional factors.This review provides a general overview of the mechanism of action of nuclear receptors and their transcriptional crosstalk with transcriptional factors associated with cytokine transduction pathways.One of the most important mechanistic aspects is protein to protein interaction through a direct or co-regulator-mediated indirect manner.Such crosstalk is crucially involved in physiological and therapeutic roles of nuclear receptors and their iigands in immunity, inflammation and cytokine-related tumors.Cellular & Molecular Immunology.2004;1(6):416-424.
文摘Although auxin and brassinosteroid （BR） synergistically control various plant responses, the molecular mechanism underlying the auxin-BR crosstalk is not wen understood. We previously identified SMOS1, an auxin-regulated APETALA2-type transcription factor, as the causal gene of the small organ size 1 （smosl） mutant that is characterized by a decreased final size of various organs in rice. In this study, we identified another smos mutant, smos2, which shows the phenotype indistinguishable from smosl. SMOS2 was identical to the previously reported DWARF AND LOWoTILLERING （DLT）, which encodes a GRAS protein involved in BR signaling. SMOS1 and SMOS2/DLT physically interact to cooperatively enhance transcriptional transactivation activity in yeast and in rice nuclei. Consistently, the expression of OsPHI-1, a direct target of SMOS1, is upregulated only when SMOS1 and SMOS2/DLT proteins are both present in rice ceils. Taken together, our results suggest that SMOS1 and SMOS2/DLT form a keystone complex on auxin-BR signaling crosstalk in rice.
