核酸适配体是人工合成的短链核酸,作为分子识别元件,能够与各类靶标物质高特异性、高亲和力的结合,分为单链DNA和RNA两种类型。其中单链DNA适配体由于其稳定性比RNA适配体更好而更受欢迎,因此得到广泛应用。核酸适配体筛选通常是通过配...核酸适配体是人工合成的短链核酸,作为分子识别元件,能够与各类靶标物质高特异性、高亲和力的结合,分为单链DNA和RNA两种类型。其中单链DNA适配体由于其稳定性比RNA适配体更好而更受欢迎,因此得到广泛应用。核酸适配体筛选通常是通过配体指数富集系统进化技术(systematic evolution of ligands by exponential enrichment,SELEX)实现的,筛选能否成功在很大程度上取决于其最关键的单链制备步骤,即将双链DNA转化为相应的单链DNA。目前,存在许多方法可以制备单链DNA,包括热变性法、生物素-链霉亲和素亲和分离法、变性胶电泳分离法、核酸外切酶消化法、不对称聚合酶链式反应(polymerase chain reaction,PCR)法等。本文在总结文献报道的基础上,具体阐述了各种单链DNA制备方法的原理、优缺点及近5年的应用情况,并对这些单链DNA制备方法进行了比较和展望,以期能为成功筛选各类靶标的核酸适配体提供参考。展开更多
The unstable zinc(Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries.Herein,the hydroxy-rich sorbitol was used as an addi...The unstable zinc(Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries.Herein,the hydroxy-rich sorbitol was used as an additive to reshape the solvation structure and modulate the interface chemistry.The strong interactions among sorbitol and both water molecules and Zn electrode can reduce the free water activity,optimize the solvation shell of water and Zn^(2+)ions,and regulate the formation of local water(H_(2)O)-poor environment on the surface of Zn electrode,which effectively inhibit the decomposition of water molecules,and thus,achieve the thermodynamically stable and highly reversible Zn electrochemistry.As a result,the assembled Zn/Zn symmetric cells with the sorbitol additive realized an excellent cycling life of 2000 h at 1 mA·cm^(-2)and 1 mAh·cm^(-2),and over 250 h at 5 mA.cm^(-2)and 5 mAh.cm^(-2).Moreover,the Zn/Cu asymmetric cells with the sorbitol additive achieved a high Coulombic efficiency of 99.6%,obtaining a better performance than that with a pure 2 mol-L^(-1)ZnSO_(4)electrolyte.And the constructed Zn/poly1,5-naphthalenediamine(PNDA)batteries could be stably discharged for 2300 cycles at 1 A g^(-1)with an excellent capacity retention rate.This result indicates that the addition of 1 mol-L^(-1)non-toxic sorbitol into a conventional ZnSO_(4)electrolyte can successfully protect the Zn anode interface by improving the electrochemical properties of Zn reversible deposition/decomposition,which greatly promotes its cycle performance,providing a new approach in future development of high performance aqueous Zn ion batteries.展开更多
上海作为我国最大的城市之一,人口密集,人类活动频繁,原生植被物种多样性受人为干扰严重。作为古老的孑遗植物,蕨类植物对生长和繁殖环境要求严格,能够灵敏地指示环境变化。为摸清上海市国土空间生态环境现状,调查团队在上海市全域土地...上海作为我国最大的城市之一,人口密集,人类活动频繁,原生植被物种多样性受人为干扰严重。作为古老的孑遗植物,蕨类植物对生长和繁殖环境要求严格,能够灵敏地指示环境变化。为摸清上海市国土空间生态环境现状,调查团队在上海市全域土地综合整治项目区内展开长期定点监测,期间在奉贤区西渡街道辖区发现了上海蕨类植物新记录种——柄叶瓶尔小草(Ophioglossum petiolatum Hook.)。文章对新记录种的形态特征和发现生境进行描述,讨论了Flora of China与《云南植物志》对其形态描述的差异,认为《云南植物志》中的描述与原始发表文献和模式标本更为接近,即该种的重要特征为其不育叶的基部下延呈柄状。柄叶瓶尔小草在江浙沪地区亦属首次报道,此次发现扩大了该种向东和北的分布记录,对研究蕨类区系分布有推进作用;瓶尔小草属植物近年来在华东地区较为罕见,本次发现地位于上海市全域土地综合整治项目区内的生态公益林,彰显了上海城市森林建设的生态效能。最后,建议将保护珍稀物种及其生境的理念融入全域土地综合整治工作,为指导大都市国土综合整治和生态保护修复工作提供新思路和新挑战。展开更多
文摘核酸适配体是人工合成的短链核酸,作为分子识别元件,能够与各类靶标物质高特异性、高亲和力的结合,分为单链DNA和RNA两种类型。其中单链DNA适配体由于其稳定性比RNA适配体更好而更受欢迎,因此得到广泛应用。核酸适配体筛选通常是通过配体指数富集系统进化技术(systematic evolution of ligands by exponential enrichment,SELEX)实现的,筛选能否成功在很大程度上取决于其最关键的单链制备步骤,即将双链DNA转化为相应的单链DNA。目前,存在许多方法可以制备单链DNA,包括热变性法、生物素-链霉亲和素亲和分离法、变性胶电泳分离法、核酸外切酶消化法、不对称聚合酶链式反应(polymerase chain reaction,PCR)法等。本文在总结文献报道的基础上,具体阐述了各种单链DNA制备方法的原理、优缺点及近5年的应用情况,并对这些单链DNA制备方法进行了比较和展望,以期能为成功筛选各类靶标的核酸适配体提供参考。
基金supported by the National Natural Science Foundation of China(22279063,52001170)Tianjin Natural Science Foundation(22JCYBJC00590)the Fundamental Research Funds for the Central Universities.We thank the Haihe Laboratoryof Sustainable Chemical Transformations for financial support.
文摘The unstable zinc(Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries.Herein,the hydroxy-rich sorbitol was used as an additive to reshape the solvation structure and modulate the interface chemistry.The strong interactions among sorbitol and both water molecules and Zn electrode can reduce the free water activity,optimize the solvation shell of water and Zn^(2+)ions,and regulate the formation of local water(H_(2)O)-poor environment on the surface of Zn electrode,which effectively inhibit the decomposition of water molecules,and thus,achieve the thermodynamically stable and highly reversible Zn electrochemistry.As a result,the assembled Zn/Zn symmetric cells with the sorbitol additive realized an excellent cycling life of 2000 h at 1 mA·cm^(-2)and 1 mAh·cm^(-2),and over 250 h at 5 mA.cm^(-2)and 5 mAh.cm^(-2).Moreover,the Zn/Cu asymmetric cells with the sorbitol additive achieved a high Coulombic efficiency of 99.6%,obtaining a better performance than that with a pure 2 mol-L^(-1)ZnSO_(4)electrolyte.And the constructed Zn/poly1,5-naphthalenediamine(PNDA)batteries could be stably discharged for 2300 cycles at 1 A g^(-1)with an excellent capacity retention rate.This result indicates that the addition of 1 mol-L^(-1)non-toxic sorbitol into a conventional ZnSO_(4)electrolyte can successfully protect the Zn anode interface by improving the electrochemical properties of Zn reversible deposition/decomposition,which greatly promotes its cycle performance,providing a new approach in future development of high performance aqueous Zn ion batteries.
文摘上海作为我国最大的城市之一,人口密集,人类活动频繁,原生植被物种多样性受人为干扰严重。作为古老的孑遗植物,蕨类植物对生长和繁殖环境要求严格,能够灵敏地指示环境变化。为摸清上海市国土空间生态环境现状,调查团队在上海市全域土地综合整治项目区内展开长期定点监测,期间在奉贤区西渡街道辖区发现了上海蕨类植物新记录种——柄叶瓶尔小草(Ophioglossum petiolatum Hook.)。文章对新记录种的形态特征和发现生境进行描述,讨论了Flora of China与《云南植物志》对其形态描述的差异,认为《云南植物志》中的描述与原始发表文献和模式标本更为接近,即该种的重要特征为其不育叶的基部下延呈柄状。柄叶瓶尔小草在江浙沪地区亦属首次报道,此次发现扩大了该种向东和北的分布记录,对研究蕨类区系分布有推进作用;瓶尔小草属植物近年来在华东地区较为罕见,本次发现地位于上海市全域土地综合整治项目区内的生态公益林,彰显了上海城市森林建设的生态效能。最后,建议将保护珍稀物种及其生境的理念融入全域土地综合整治工作,为指导大都市国土综合整治和生态保护修复工作提供新思路和新挑战。
