用PCR法合成人胰岛素基因,克隆到pUC18载体上,经测序证实其碱基序列与人胰岛素基因的序列完全一致。本实验还构建了银耳表达载体,由限制性内切酶介导(Restriction enzy me-mediated DNA Integration,REMI)转化银耳芽孢。随机挑取21个抗...用PCR法合成人胰岛素基因,克隆到pUC18载体上,经测序证实其碱基序列与人胰岛素基因的序列完全一致。本实验还构建了银耳表达载体,由限制性内切酶介导(Restriction enzy me-mediated DNA Integration,REMI)转化银耳芽孢。随机挑取21个抗性菌落,转管繁殖2代后检测其GUS活性,实验结果:18个菌株阳性,3个菌株阴性。从这21个菌株中选取10个菌株,提取染色体DNA,用人胰岛素基因、GUS基因和Tnos序列的特异引物进行PCR,结果表明,这10菌株都能扩增出相应长度的特异片段,证明了它们是人胰岛素基因转化子。展开更多
Salt cress （Thellungiella halophila）, a close relative of the model plant Arabidopsis thaliana L., is an extremophile that is adapted to harsh saline environments. To mine salt-tolerance genes from this species, we ...Salt cress （Thellungiella halophila）, a close relative of the model plant Arabidopsis thaliana L., is an extremophile that is adapted to harsh saline environments. To mine salt-tolerance genes from this species, we constructed an entry cDNA library from the salt cress plant treated with salt-stress by using a modified cDNA synthesis and an improved recombinationassisted cDNA library construction method that is completely free of manipulations involving restriction enzymes and DNA ligase. This cDNA library construction procedure is significantly simplified and the quality of the cDNA library is improved. This entry cDNA library was subsequently shuttled into the destination binary vector pCB406 designed for plant transformation and expression via recombination-assisted cloning. The library is plant transformation ready and is used to transform Arabidopsis on a large scale in order to create a large collection of transgenic lines for functional gene mining.展开更多
Near-monodisperse NaYF4：Yb/Er nanoparticles（NPs） with controlled size, phases（α,β） and shapes（sphere, and hexagonal plate） were synthesized by adjusting the NaF to RE（RE = Y, Yb, Er） ratios, the reaction te...Near-monodisperse NaYF4：Yb/Er nanoparticles（NPs） with controlled size, phases（α,β） and shapes（sphere, and hexagonal plate） were synthesized by adjusting the NaF to RE（RE = Y, Yb, Er） ratios, the reaction temperature and time in the hot surfactant solutions（oleic acid, 1-octadecene） from the improved one-pot thermal decomposition metal trifluoroacetate, and the precursors were prepared via hydrothermal route. The growth kinetics of β-NaYF4 NPs includes several stages： nucleation, growth of aNaYF4, Ostwald ripening, size shrinkage and growth. The results prove that the temperatures are preferred to the phase transformation compared with the NaF content when other experimental conditions are unchanged. Our work will further facilitate the comprehension of the nucleation and growth mechanisms of the NPs, and provide guidance for their controlled synthesis.展开更多
Lead halide perovskite nanocrystals(NCs)exhibit excellent optoelectronic performance and have drawn great interests in the fields of biological imaging and sensing.However,the poor stability of CsPbX_(3)(X=Cl,Br,I)in ...Lead halide perovskite nanocrystals(NCs)exhibit excellent optoelectronic performance and have drawn great interests in the fields of biological imaging and sensing.However,the poor stability of CsPbX_(3)(X=Cl,Br,I)in water is still a challenge to hinder their practical applications.In this work,a facile strategy has been developed for aqueous synthesis of CsPbX_(3) nanocrystals,in which L-glutamic acid(LGlu)has been used to replace oleic acid in the synthetic process.Benefiting from the synergic effects of L-Glu and oleylamine(OAm),CsPbBr_(3)nanocrystals(L-Glu/OAm-CsPbBr_(3)NCs)with high water stability have been directly prepared under a mild condition at room temperature in water,facilitated by the process of crystal phase transformation from Cs_(4)PbBr_(6) to CsPbBr_(3).L-Glu/OAm-CsPbBr_(3)NCs exhibit a high quantum yield of 85%and a narrow full width at half maximum of 16 nm,demonstrating their efficient luminescence in water.Typically,L-Glu on the surface have contributed greatly to an acidic environment and passivation of surface defects,improving the water stability and dispersibility of CsPbBr_(3)nanocrystals.Moreover,L-Glu/OAm-CsPbBr_(3)NCs exhibit great biocompatibility due to the presence of L-Glu,resulting in their good performance for HeLa cell imaging.Thus,we propose a facile and effective method to prepare CsPbBr_(3)nanocrystals with excellent water stability by using L-Glu and OAm as cooperated ligands and expand their application in cell imaging.展开更多
Isomerism is an essential and widespread phenomenon in organic chemistry but rarely observed in covalent organic frameworks(COFs),a novel class of crystalline porous organic polymers with versatile applications.Herein...Isomerism is an essential and widespread phenomenon in organic chemistry but rarely observed in covalent organic frameworks(COFs),a novel class of crystalline porous organic polymers with versatile applications.Herein,we give an account of the first example of a controllable synthesis of constitutional isomers of a COF.The two isomers exhibited marked differences in their gas/vapor adsorption behaviors and chemical stability in various solvents.Furthermore,structure transformation from one isomer to the other was realized.This work not only paves the way for rational design and synthesis of COF isomers but also provides a vivid example of structure–property relationship in crystalline porous polymers.展开更多
文摘用PCR法合成人胰岛素基因,克隆到pUC18载体上,经测序证实其碱基序列与人胰岛素基因的序列完全一致。本实验还构建了银耳表达载体,由限制性内切酶介导(Restriction enzy me-mediated DNA Integration,REMI)转化银耳芽孢。随机挑取21个抗性菌落,转管繁殖2代后检测其GUS活性,实验结果:18个菌株阳性,3个菌株阴性。从这21个菌株中选取10个菌株,提取染色体DNA,用人胰岛素基因、GUS基因和Tnos序列的特异引物进行PCR,结果表明,这10菌株都能扩增出相应长度的特异片段,证明了它们是人胰岛素基因转化子。
基金the Hi-Tech Research and Development(863)Program of China(2002AA224071)the Chinese Academy of Sciences(KSCX2-SW-3).
文摘Salt cress （Thellungiella halophila）, a close relative of the model plant Arabidopsis thaliana L., is an extremophile that is adapted to harsh saline environments. To mine salt-tolerance genes from this species, we constructed an entry cDNA library from the salt cress plant treated with salt-stress by using a modified cDNA synthesis and an improved recombinationassisted cDNA library construction method that is completely free of manipulations involving restriction enzymes and DNA ligase. This cDNA library construction procedure is significantly simplified and the quality of the cDNA library is improved. This entry cDNA library was subsequently shuttled into the destination binary vector pCB406 designed for plant transformation and expression via recombination-assisted cloning. The library is plant transformation ready and is used to transform Arabidopsis on a large scale in order to create a large collection of transgenic lines for functional gene mining.
基金Project supported by the National Natural Science Foundation of China(2126016)the Science and Technology Innovation Guidance Project,Inner Mongolia,China(000-21090179)+2 种基金the Talents Project Inner Mongolia(CYYC:5026)the Opened Fund of the State Key Laboratory on integrated Optoelectronics(China IOSKL2013KF08)the Graduate Student Scientific Research Foundation of Inner Mongolia(S20161013505)
文摘Near-monodisperse NaYF4：Yb/Er nanoparticles（NPs） with controlled size, phases（α,β） and shapes（sphere, and hexagonal plate） were synthesized by adjusting the NaF to RE（RE = Y, Yb, Er） ratios, the reaction temperature and time in the hot surfactant solutions（oleic acid, 1-octadecene） from the improved one-pot thermal decomposition metal trifluoroacetate, and the precursors were prepared via hydrothermal route. The growth kinetics of β-NaYF4 NPs includes several stages： nucleation, growth of aNaYF4, Ostwald ripening, size shrinkage and growth. The results prove that the temperatures are preferred to the phase transformation compared with the NaF content when other experimental conditions are unchanged. Our work will further facilitate the comprehension of the nucleation and growth mechanisms of the NPs, and provide guidance for their controlled synthesis.
基金support from the National Natural Science Foundation of China(Nos.22221001,and 22131007)the Science and Technology Major Plan of Gansu Province(No.23ZDGA012)the 111 project(No.B20027).
文摘Lead halide perovskite nanocrystals(NCs)exhibit excellent optoelectronic performance and have drawn great interests in the fields of biological imaging and sensing.However,the poor stability of CsPbX_(3)(X=Cl,Br,I)in water is still a challenge to hinder their practical applications.In this work,a facile strategy has been developed for aqueous synthesis of CsPbX_(3) nanocrystals,in which L-glutamic acid(LGlu)has been used to replace oleic acid in the synthetic process.Benefiting from the synergic effects of L-Glu and oleylamine(OAm),CsPbBr_(3)nanocrystals(L-Glu/OAm-CsPbBr_(3)NCs)with high water stability have been directly prepared under a mild condition at room temperature in water,facilitated by the process of crystal phase transformation from Cs_(4)PbBr_(6) to CsPbBr_(3).L-Glu/OAm-CsPbBr_(3)NCs exhibit a high quantum yield of 85%and a narrow full width at half maximum of 16 nm,demonstrating their efficient luminescence in water.Typically,L-Glu on the surface have contributed greatly to an acidic environment and passivation of surface defects,improving the water stability and dispersibility of CsPbBr_(3)nanocrystals.Moreover,L-Glu/OAm-CsPbBr_(3)NCs exhibit great biocompatibility due to the presence of L-Glu,resulting in their good performance for HeLa cell imaging.Thus,we propose a facile and effective method to prepare CsPbBr_(3)nanocrystals with excellent water stability by using L-Glu and OAm as cooperated ligands and expand their application in cell imaging.
基金the National Science Fund for Distinguished Young Scholars of China(no.21725404)Shanghai Scientific and Technological Innovation Project(18JC1410600)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB20000000)for financial support.
文摘Isomerism is an essential and widespread phenomenon in organic chemistry but rarely observed in covalent organic frameworks(COFs),a novel class of crystalline porous organic polymers with versatile applications.Herein,we give an account of the first example of a controllable synthesis of constitutional isomers of a COF.The two isomers exhibited marked differences in their gas/vapor adsorption behaviors and chemical stability in various solvents.Furthermore,structure transformation from one isomer to the other was realized.This work not only paves the way for rational design and synthesis of COF isomers but also provides a vivid example of structure–property relationship in crystalline porous polymers.
