[ Objective] This study aimed to investigate the expression of recombinant protein of fibroblast growth factor 21 （ FGF21 ） in Escherichia coli induced by lactose and explore the possibility of engineering productio...[ Objective] This study aimed to investigate the expression of recombinant protein of fibroblast growth factor 21 （ FGF21 ） in Escherichia coli induced by lactose and explore the possibility of engineering production. [ Method ] The effects of lactose concentration, induction duration, induction starting time, and induc- tion temperature on expression of the recombinant product were compared, and the optimal condition for lactose induction was determined with IPTG induction as a control. [ Result] As an induction agent, lactose plays an ideal rele in the production of recombinant FGF21. In addition, the expression level of lactose induction product is consistent with that of IPTG induction product. Induction in a 250 rrd flask containing 50 ml of medium at A600 0.8 - 1.0 using 0.5 g/L lactose at 35 ℃ for 6 h are the optimal condition. [ Conclusion] Lactose can induce the expression of FGF21 gene and achieve ideal results. This study provides experimental basis and reference for the industrial production of FGF21.展开更多
MXene,as a rising star among two-dimensional(2D)electromagnetic wave materials,faces urgent challenges in addressing its self-stacking issue and regulating its conductivity.Herein,a micro-macro collaborative design st...MXene,as a rising star among two-dimensional(2D)electromagnetic wave materials,faces urgent challenges in addressing its self-stacking issue and regulating its conductivity.Herein,a micro-macro collaborative design strategy was proposed to regulate heterogeneous interface engineering in MXene-based absorbers.Biomass-based cotton was introduced as three dimensional(3D)framework for constructing a porous structure,TiO_(2) was in-situ generated and nitrogen atom was doped on Ti_(3)C_(2)T_(x) MXene to regulate its dielectric properties,a 3D N-doped carbon fiber/MXene/TiO_(2)(CMT)nano-aerogel was successful constructed.The synergistic effects of diverse components and structural designs,porous frameworks and TiO_(2) lattice contraction can significantly adjust the density of the conductive network and create abundant heterogeneous interfaces,as well as the lattice defects induced by nitrogen atom doping can enhance polarization loss,ultimately leading to the excellent microwave absorption performance of 3D N-CMT nano-aerogels.The optimized N-CMT 30%aerogel exhibited a minimum reflection loss(RLmin)of−72.56 dB and an effective absorption bandwidth(EAB)of 6.92 GHz at 2.23 mm.Notably,when the thickness was adjusted from 1 to 5 mm,the EAB of the N-CMT 30%aerogel reached 13.94 GHz,achieving coverage of 98% of the C-band and the entire X and Ku bands.Furthermore,the attenuation capabilities of the N-CMT aerogel were further confirmed through RCS simulations,whose RCS reduction value reaches up to 19.969 dB·m^(2).These results demonstrate that 3D N-CMT nano-aerogel relying on interface engineering design exhibits significant potential in the field of electromagnetic protection,providing an important reference for future efficient absorbers.展开更多
基金Supported by Science and Technology Development Fund of Jilin Province(20090949,20116044)Student Research Fund from Jilin Medical College([2010]No.09)
文摘[ Objective] This study aimed to investigate the expression of recombinant protein of fibroblast growth factor 21 （ FGF21 ） in Escherichia coli induced by lactose and explore the possibility of engineering production. [ Method ] The effects of lactose concentration, induction duration, induction starting time, and induc- tion temperature on expression of the recombinant product were compared, and the optimal condition for lactose induction was determined with IPTG induction as a control. [ Result] As an induction agent, lactose plays an ideal rele in the production of recombinant FGF21. In addition, the expression level of lactose induction product is consistent with that of IPTG induction product. Induction in a 250 rrd flask containing 50 ml of medium at A600 0.8 - 1.0 using 0.5 g/L lactose at 35 ℃ for 6 h are the optimal condition. [ Conclusion] Lactose can induce the expression of FGF21 gene and achieve ideal results. This study provides experimental basis and reference for the industrial production of FGF21.
基金This work was supported by Joint Funds of the National Natural Science Foundation of China(Nos.U22A20244,U23A20673 and 52478261)Qingchuang Technology Project under Grant 2021KJ045,Demonstration Project of Benefiting People with Science and Technology of Qingdao,China(No.24-1-8-cspz-9 nsh)the China Postdoctoral Science Foundation(No.2024M750580).
文摘MXene,as a rising star among two-dimensional(2D)electromagnetic wave materials,faces urgent challenges in addressing its self-stacking issue and regulating its conductivity.Herein,a micro-macro collaborative design strategy was proposed to regulate heterogeneous interface engineering in MXene-based absorbers.Biomass-based cotton was introduced as three dimensional(3D)framework for constructing a porous structure,TiO_(2) was in-situ generated and nitrogen atom was doped on Ti_(3)C_(2)T_(x) MXene to regulate its dielectric properties,a 3D N-doped carbon fiber/MXene/TiO_(2)(CMT)nano-aerogel was successful constructed.The synergistic effects of diverse components and structural designs,porous frameworks and TiO_(2) lattice contraction can significantly adjust the density of the conductive network and create abundant heterogeneous interfaces,as well as the lattice defects induced by nitrogen atom doping can enhance polarization loss,ultimately leading to the excellent microwave absorption performance of 3D N-CMT nano-aerogels.The optimized N-CMT 30%aerogel exhibited a minimum reflection loss(RLmin)of−72.56 dB and an effective absorption bandwidth(EAB)of 6.92 GHz at 2.23 mm.Notably,when the thickness was adjusted from 1 to 5 mm,the EAB of the N-CMT 30%aerogel reached 13.94 GHz,achieving coverage of 98% of the C-band and the entire X and Ku bands.Furthermore,the attenuation capabilities of the N-CMT aerogel were further confirmed through RCS simulations,whose RCS reduction value reaches up to 19.969 dB·m^(2).These results demonstrate that 3D N-CMT nano-aerogel relying on interface engineering design exhibits significant potential in the field of electromagnetic protection,providing an important reference for future efficient absorbers.
