核基质蛋白Ciz1(Cdkn1A-interacting zinc finger protein 1)是在酵母双杂交系统中寻找能与p21Cip1/Waf1结合并调节其细胞核定位时发现的锌指蛋白。当分别过表达Ciz1和p21Cip1/Waf1时,它们均主要定位于细胞核,而当共转染时,则均从细胞...核基质蛋白Ciz1(Cdkn1A-interacting zinc finger protein 1)是在酵母双杂交系统中寻找能与p21Cip1/Waf1结合并调节其细胞核定位时发现的锌指蛋白。当分别过表达Ciz1和p21Cip1/Waf1时,它们均主要定位于细胞核,而当共转染时,则均从细胞核转位到细胞质。在小鼠3T3细胞中,Ciz1可以协同CDK2、细胞周期蛋白E和细胞周期蛋白A启动DNA的复制,并促进细胞由G1期进入S期。此外,Ciz1还具有结合DNA的能力并参与对转录因子的活性调控,同时,Ciz1还可能作为蛋白激酶ATM的底物参与DNA的损伤修复。近年来研究发现,Ciz1除与阿尔茨海默病和肌张力失常等疾病相关以外,还在肺癌、结肠癌和乳腺癌等多种肿瘤组织中呈现高表达,参与肿瘤的发生和发展过程。本文主要就Ciz1的结构功能及与肿瘤的关系作一综述。展开更多
传统的铁碳微电解材料主要用于降解有机物、除重金属和废水脱色,但其吸氮除磷效果差,且易板结、钝化、净水效果差、不能再生,限制了它的广泛应用。本文以铁粉、碳粉、绿沸石、炉渣、粘结剂等为原料,采用煅烧法制得兼具吸氮除磷脱碳功能...传统的铁碳微电解材料主要用于降解有机物、除重金属和废水脱色,但其吸氮除磷效果差,且易板结、钝化、净水效果差、不能再生,限制了它的广泛应用。本文以铁粉、碳粉、绿沸石、炉渣、粘结剂等为原料,采用煅烧法制得兼具吸氮除磷脱碳功能的新型铁碳微电解复合材料(CIZS),并对CIZS的形貌结构、物理性质进行了表征,对其最佳制备条件、最佳水处理条件、再生性能、吸附动力学等进行了探究。结果表明,CIZS的最佳制备条件为铁碳质量比为3∶1,绿沸石∶炉渣∶铁碳材料的质量比为5∶1∶9,此时所得CIZS孔隙率高,表面粗糙,筒压强度18.33 MPa,1 h吸水率24.68%,堆积密度894.8 kg/m^(3)。CIZS的最佳水处理条件为:在25℃下,废水初始pH=3,在200 mL废水中投加7 g CIZS、1 mL H_(2)O_(2),处理12 h后的COD、NH_(4)^(+)-N、TP的去除率最高,分别为93.54%、84.41%、92.90%。CIZS再生3次去除效果无明显下降,最佳再生方式为超声+NaCl浸泡。CIZS对NH_(4)^(+)-N、TP的吸附过程主要以化学吸附为主,均符合准二级动力学。研究结果能为废弃物的资源化利用和水处理领域提供新技术和新材料。展开更多
The efficiency of N2-fixation in legume-rhizobia symbiosis is a function of root nodule activity.Nodules consist of 2 functionally important tissues:(a)a central infected zone(CIZ),colonized by rhizobia bacteria,which...The efficiency of N2-fixation in legume-rhizobia symbiosis is a function of root nodule activity.Nodules consist of 2 functionally important tissues:(a)a central infected zone(CIZ),colonized by rhizobia bacteria,which serves as the site of N2-fixation,and(b)vascular bundles(VBs),serving as conduits for the transport of water,nutrients,and fixed nitrogen compounds between the nodules and plant.A quantitative evaluation of these tissues is essential to unravel their functional importance in N2-fixation.Employing synchrotron-based x-ray microcomputed tomography(SR-μCT)at submicron resolutions,we obtained high-quality tomograms of fresh soybean root nodules in a non-invasive manner.A semi-automated segmentation algorithm was employed to generate 3-dimensional(3D)models of the internal root nodule structure of the CIZ and VBs,and their volumes were quantified based on the reconstructed 3D structures.Furthermore,synchrotron x-ray fluorescence imaging revealed a distinctive localization of Fe within CIZ tissue and Zn within VBs,allowing for their visualization in 2 dimensions.This study represents a pioneer application of the SR-μCT technique for volumetric quantification of CIZ and VB tissues in fresh,intact soybean root nodules.The proposed methods enable the exploitation of root nodule's anatomical features as novel traits in breeding,aiming to enhance N2-fixation through improved root nodule activity.展开更多
文摘核基质蛋白Ciz1(Cdkn1A-interacting zinc finger protein 1)是在酵母双杂交系统中寻找能与p21Cip1/Waf1结合并调节其细胞核定位时发现的锌指蛋白。当分别过表达Ciz1和p21Cip1/Waf1时,它们均主要定位于细胞核,而当共转染时,则均从细胞核转位到细胞质。在小鼠3T3细胞中,Ciz1可以协同CDK2、细胞周期蛋白E和细胞周期蛋白A启动DNA的复制,并促进细胞由G1期进入S期。此外,Ciz1还具有结合DNA的能力并参与对转录因子的活性调控,同时,Ciz1还可能作为蛋白激酶ATM的底物参与DNA的损伤修复。近年来研究发现,Ciz1除与阿尔茨海默病和肌张力失常等疾病相关以外,还在肺癌、结肠癌和乳腺癌等多种肿瘤组织中呈现高表达,参与肿瘤的发生和发展过程。本文主要就Ciz1的结构功能及与肿瘤的关系作一综述。
文摘传统的铁碳微电解材料主要用于降解有机物、除重金属和废水脱色,但其吸氮除磷效果差,且易板结、钝化、净水效果差、不能再生,限制了它的广泛应用。本文以铁粉、碳粉、绿沸石、炉渣、粘结剂等为原料,采用煅烧法制得兼具吸氮除磷脱碳功能的新型铁碳微电解复合材料(CIZS),并对CIZS的形貌结构、物理性质进行了表征,对其最佳制备条件、最佳水处理条件、再生性能、吸附动力学等进行了探究。结果表明,CIZS的最佳制备条件为铁碳质量比为3∶1,绿沸石∶炉渣∶铁碳材料的质量比为5∶1∶9,此时所得CIZS孔隙率高,表面粗糙,筒压强度18.33 MPa,1 h吸水率24.68%,堆积密度894.8 kg/m^(3)。CIZS的最佳水处理条件为:在25℃下,废水初始pH=3,在200 mL废水中投加7 g CIZS、1 mL H_(2)O_(2),处理12 h后的COD、NH_(4)^(+)-N、TP的去除率最高,分别为93.54%、84.41%、92.90%。CIZS再生3次去除效果无明显下降,最佳再生方式为超声+NaCl浸泡。CIZS对NH_(4)^(+)-N、TP的吸附过程主要以化学吸附为主,均符合准二级动力学。研究结果能为废弃物的资源化利用和水处理领域提供新技术和新材料。
基金supported by funding from a Canada Excellence Research Chairs(CERC)Grant to L.K.from funding from the Global Institute for Food Security and the University of Saskatchewan,to L.K.
文摘The efficiency of N2-fixation in legume-rhizobia symbiosis is a function of root nodule activity.Nodules consist of 2 functionally important tissues:(a)a central infected zone(CIZ),colonized by rhizobia bacteria,which serves as the site of N2-fixation,and(b)vascular bundles(VBs),serving as conduits for the transport of water,nutrients,and fixed nitrogen compounds between the nodules and plant.A quantitative evaluation of these tissues is essential to unravel their functional importance in N2-fixation.Employing synchrotron-based x-ray microcomputed tomography(SR-μCT)at submicron resolutions,we obtained high-quality tomograms of fresh soybean root nodules in a non-invasive manner.A semi-automated segmentation algorithm was employed to generate 3-dimensional(3D)models of the internal root nodule structure of the CIZ and VBs,and their volumes were quantified based on the reconstructed 3D structures.Furthermore,synchrotron x-ray fluorescence imaging revealed a distinctive localization of Fe within CIZ tissue and Zn within VBs,allowing for their visualization in 2 dimensions.This study represents a pioneer application of the SR-μCT technique for volumetric quantification of CIZ and VB tissues in fresh,intact soybean root nodules.The proposed methods enable the exploitation of root nodule's anatomical features as novel traits in breeding,aiming to enhance N2-fixation through improved root nodule activity.
