{"title":"Polymer Functionalized Graphene","authors":"","doi":"10.1039/9781788019675","DOIUrl":"https://doi.org/10.1039/9781788019675","url":null,"abstract":"","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73851823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-23DOI: 10.1039/9781788015769-00277
S. Tan, N. Chan, Joe Collins, Q. Fu, G. Qiao
Since the 1960s, polymer network hydrogels have been used for various applications. However, these applications have been restricted to non-load-bearing ones, due to the inherent mechanical weakness of common hydrogels. This weakness is attributed to the irregular crosslinking density, the high proportion of singly-attached (dangling and, therefore, elastically inactive) chains and the broadly varying distance between crosslinking points. In recent years, ground-breaking studies focusing on the development of novel approaches to fabricate near-ideal polymer network hydrogels with excellent mechanical properties have been developed. In this chapter, these new approaches will be outlined, with specific interest in amphiphilic polymer co-networks (APCNs), i.e. networks containing both hydrophilic and hydrophobic domains. The ability to generate these near-ideal networks, which often also possess ‘smart’ stimuli-responsive properties, would allow APCNs to be used in a wide range of advanced applications, including soft robotics, biomaterials and materials science. These new synthetic methodologies will be described in this chapter and will be separated into either fundamentally altering the network architecture and/or by employing facile and orthogonal coupling chemistries.
{"title":"CHAPTER 13. New Approaches Towards the Design of Tough Amphiphilic Polymeric Co-networks","authors":"S. Tan, N. Chan, Joe Collins, Q. Fu, G. Qiao","doi":"10.1039/9781788015769-00277","DOIUrl":"https://doi.org/10.1039/9781788015769-00277","url":null,"abstract":"Since the 1960s, polymer network hydrogels have been used for various applications. However, these applications have been restricted to non-load-bearing ones, due to the inherent mechanical weakness of common hydrogels. This weakness is attributed to the irregular crosslinking density, the high proportion of singly-attached (dangling and, therefore, elastically inactive) chains and the broadly varying distance between crosslinking points. In recent years, ground-breaking studies focusing on the development of novel approaches to fabricate near-ideal polymer network hydrogels with excellent mechanical properties have been developed. In this chapter, these new approaches will be outlined, with specific interest in amphiphilic polymer co-networks (APCNs), i.e. networks containing both hydrophilic and hydrophobic domains. The ability to generate these near-ideal networks, which often also possess ‘smart’ stimuli-responsive properties, would allow APCNs to be used in a wide range of advanced applications, including soft robotics, biomaterials and materials science. These new synthetic methodologies will be described in this chapter and will be separated into either fundamentally altering the network architecture and/or by employing facile and orthogonal coupling chemistries.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87141421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Redox Polymers for Energy and Nanomedicine","authors":"","doi":"10.1039/9781788019743","DOIUrl":"https://doi.org/10.1039/9781788019743","url":null,"abstract":"","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89300955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1039/9781788019743-fp007
{"title":"Contents. Contents","authors":"","doi":"10.1039/9781788019743-fp007","DOIUrl":"https://doi.org/10.1039/9781788019743-fp007","url":null,"abstract":"","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76109309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00243
Jia-Fang Lian, Jinlong Chen, Y. Tao, Xianhong Wang
Poly(e-lysine) is an uncommon cationic homopolymer and has many potential high-value applications. Due to its significant antimicrobial activity and nontoxicity to humans, poly(e-lysine) is now industrially produced by a fermentation process as an additive, e.g. for food and cosmetics. However, the biosynthetic route can only make polymers with a molecular weight of about 3 kDa. Here, we propose the use of bases for the ring-opening polymerization (ROP) of cyclic lysine (e-lactam) monomer towards poly(e-lysine). Among the evaluated bases, NaH and t-BuP2 were found to be the most effective for the polymerization of e-lactam monomer, affording poly(e-lysine) bearing pendant 2,5-dimethylpyrrole protecting groups with a number average molecular weight of up to 45 kg mol−1. Moreover, poly(e-lysine) was prepared by the removal of the 2,5-dimethylpyrrole protecting groups. Finally, a pilot-scale study was demonstrated to obtain poly(e-lysine) with Mn up to 10 kg mol−1. The new development in the ring-opening polymerization route and Mn improvement for poly(e-lysine) have created new chances for industry. In particular, the low cost of lysine may help to produce low-cost poly(e-lysine), providing a new solution that can overcome the cost problem, which has puzzled the poly(e-lysine) industry since its birth.
聚赖氨酸是一种罕见的阳离子均聚物，具有许多潜在的高价值应用。由于其显著的抗菌活性和对人体无毒，聚赖氨酸现在通过发酵过程作为添加剂在工业上生产，例如用于食品和化妆品。然而，生物合成途径只能制造分子量约为3kda的聚合物。在这里，我们提出了使用碱开环聚合(ROP)环赖氨酸(e-内酰胺)单体到聚(e-赖氨酸)。在被评估的碱基中，na和t-BuP2对e-内酰胺单体的聚合最有效，提供含有聚e-赖氨酸的垂链2,5-二甲基吡咯保护基团，其平均分子量高达45 kg mol−1。此外，通过去除2,5-二甲基吡咯保护基团制备了聚e-赖氨酸。最后，一个中试规模的研究证明，获得聚(e-赖氨酸)与Mn高达10 kg mol - 1。开环聚合路线的新发展和聚赖氨酸锰的改进为工业创造了新的机遇。特别是赖氨酸的低成本可能有助于生产低成本的聚赖氨酸，为克服成本问题提供了一种新的解决方案，这一问题自诞生以来一直困扰着聚赖氨酸行业。
{"title":"CHAPTER 8. Chemosynthesis of Poly(ε-Lysine) via Ring-opening Polymerization of Cyclic Lysine","authors":"Jia-Fang Lian, Jinlong Chen, Y. Tao, Xianhong Wang","doi":"10.1039/9781788016469-00243","DOIUrl":"https://doi.org/10.1039/9781788016469-00243","url":null,"abstract":"Poly(e-lysine) is an uncommon cationic homopolymer and has many potential high-value applications. Due to its significant antimicrobial activity and nontoxicity to humans, poly(e-lysine) is now industrially produced by a fermentation process as an additive, e.g. for food and cosmetics. However, the biosynthetic route can only make polymers with a molecular weight of about 3 kDa. Here, we propose the use of bases for the ring-opening polymerization (ROP) of cyclic lysine (e-lactam) monomer towards poly(e-lysine). Among the evaluated bases, NaH and t-BuP2 were found to be the most effective for the polymerization of e-lactam monomer, affording poly(e-lysine) bearing pendant 2,5-dimethylpyrrole protecting groups with a number average molecular weight of up to 45 kg mol−1. Moreover, poly(e-lysine) was prepared by the removal of the 2,5-dimethylpyrrole protecting groups. Finally, a pilot-scale study was demonstrated to obtain poly(e-lysine) with Mn up to 10 kg mol−1. The new development in the ring-opening polymerization route and Mn improvement for poly(e-lysine) have created new chances for industry. In particular, the low cost of lysine may help to produce low-cost poly(e-lysine), providing a new solution that can overcome the cost problem, which has puzzled the poly(e-lysine) industry since its birth.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77260778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00167
Xiao‐Bing Lu
The desymmetrization copolymerization of meso-epoxides with achiral nucleophiles mediated by chiral reagents or catalysts is an efficacious synthetic strategy for preparing optically active polymers with two contiguous (R,R)- or (S,S)-configurational stereogenic centers. This chapter describes in general terms the catalytic polymerization methodology regarding the use of meso-epoxides in desymmetrization copolymerization promoted by multichiral induction and bimetallic synergistic effects for achieving both high activity and enantioselectivity. The major focus will be on the most successful catalyst systems based on enantiopure bimetallic complexes in recent years and the preferred chiral ligand frameworks leading to elevated reactivity and enantioselectivity in meso-epoxide desymmetrization copolymerization reactions, including enantioselective synthesis of polycarbonates from carbon dioxide, poly(thiocarbonate)s from carbonyl sulfide, and polyesters from cyclic anhydrides.
{"title":"CHAPTER 6. Bimetallic Complex Mediated Meso-epoxide Desymmetrization Copolymerization","authors":"Xiao‐Bing Lu","doi":"10.1039/9781788016469-00167","DOIUrl":"https://doi.org/10.1039/9781788016469-00167","url":null,"abstract":"The desymmetrization copolymerization of meso-epoxides with achiral nucleophiles mediated by chiral reagents or catalysts is an efficacious synthetic strategy for preparing optically active polymers with two contiguous (R,R)- or (S,S)-configurational stereogenic centers. This chapter describes in general terms the catalytic polymerization methodology regarding the use of meso-epoxides in desymmetrization copolymerization promoted by multichiral induction and bimetallic synergistic effects for achieving both high activity and enantioselectivity. The major focus will be on the most successful catalyst systems based on enantiopure bimetallic complexes in recent years and the preferred chiral ligand frameworks leading to elevated reactivity and enantioselectivity in meso-epoxide desymmetrization copolymerization reactions, including enantioselective synthesis of polycarbonates from carbon dioxide, poly(thiocarbonate)s from carbonyl sulfide, and polyesters from cyclic anhydrides.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76980397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The field of non-natural macromolecules with precisely defined structures has evolved quickly in the past few years. Absolute control over the synthesized polymer structure provides the opportunity to produce desired artificial polymers that are capable of exhibiting the same or even improved properties over those of biological macromolecules. Additionally, it will also provide theoretical guidance for the preparation of the next generation of functional polymer materials. Thiol is extremely reactive with a large number of substrates. Guided by the concept of green chemistry, thiol-X click chemistry has been employed and demonstrated to be an ideal tool for precision polymer synthesis. Herein, the general mechanisms of major reactions in thiol chemistry are introduced with a focus on their significance and potential applications. This chapter describes the releasing of thiol groups, the efficient reactions of thiol groups, and the application of thiol chemistry in precision polymer synthesis, emphasizing the contribution of thiol chemistry to precision polymer synthesis.
{"title":"CHAPTER 2. Thiol Chemistry for Precision Polymer Synthesis","authors":"Zhengbiao Zhang, Baolei Liu, Zhihao Huang, Yu-fang Zhong, Qiunan Shi, Xiu-lin Zhu","doi":"10.1039/9781788016469-00032","DOIUrl":"https://doi.org/10.1039/9781788016469-00032","url":null,"abstract":"The field of non-natural macromolecules with precisely defined structures has evolved quickly in the past few years. Absolute control over the synthesized polymer structure provides the opportunity to produce desired artificial polymers that are capable of exhibiting the same or even improved properties over those of biological macromolecules. Additionally, it will also provide theoretical guidance for the preparation of the next generation of functional polymer materials. Thiol is extremely reactive with a large number of substrates. Guided by the concept of green chemistry, thiol-X click chemistry has been employed and demonstrated to be an ideal tool for precision polymer synthesis. Herein, the general mechanisms of major reactions in thiol chemistry are introduced with a focus on their significance and potential applications. This chapter describes the releasing of thiol groups, the efficient reactions of thiol groups, and the application of thiol chemistry in precision polymer synthesis, emphasizing the contribution of thiol chemistry to precision polymer synthesis.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75268706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00001
Long Xu, Peng Wu, Jiajia Dong
Sulfur(vi) Fluoride Exchange (SuFEx) click chemistry was reported by Sharpless et al. in 2014. The applications of SuFEx click chemistry have been demonstrated in various disciplines since then, including the development of synthetic methods and the preparation of polymers. Fluorosulfates have also been found to be unique warheads for covalent capture of protein side chains in a highly selective, context-dependent manner. A review of the story of discovering SuFEx will be included in this chapter. We will also focus on the details demonstrating the whole process to synthesize new polysulfonate and polysulfate polymers, especially the evolution of the catalysts involved. Aside from leading to the discovery of new polymers, SuFEx click chemistry as a powerful tool in polymer modification will also be discussed herein.
{"title":"CHAPTER 1. New Polymers From SuFEx Click Chemistry: Syntheses and Perspectives","authors":"Long Xu, Peng Wu, Jiajia Dong","doi":"10.1039/9781788016469-00001","DOIUrl":"https://doi.org/10.1039/9781788016469-00001","url":null,"abstract":"Sulfur(vi) Fluoride Exchange (SuFEx) click chemistry was reported by Sharpless et al. in 2014. The applications of SuFEx click chemistry have been demonstrated in various disciplines since then, including the development of synthetic methods and the preparation of polymers. Fluorosulfates have also been found to be unique warheads for covalent capture of protein side chains in a highly selective, context-dependent manner. A review of the story of discovering SuFEx will be included in this chapter. We will also focus on the details demonstrating the whole process to synthesize new polysulfonate and polysulfate polymers, especially the evolution of the catalysts involved. Aside from leading to the discovery of new polymers, SuFEx click chemistry as a powerful tool in polymer modification will also be discussed herein.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74677573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00264
T. Han, J. Lam, B. Tang
Fused (hetero)cyclic polymers are an important group of functional materials with unique electrochemical and photophysical properties. They are in great demand in high-tech applications such as organic electronics and advanced optical devices. Alkyne-based polymerizations have been found to be a powerful tool for the synthesis of fused (hetero)cyclic polymers. The fused (hetero)cyclic units can form in situ in the polymer backbones during the polymerizations. In this chapter, the progress in the synthesis of fused (hetero)cyclic polymers by alkyne-based polymerizations will be summarized, including the homopolymerizations of acetylenic monomers, stoichiometric polyannulations of internal diynes and aromatics, non-stoichiometric polyannulations of internal diynes and monofunctional aromatics, and multicomponent acetylenic polymerizations. Meanwhile, the properties and functionalities of the produced fused (hetero)cyclic polymers, such as thermal and morphological stability, light refraction and chromatic dispersion, photoluminescent properties, fluorescent chemosensor, external stimuli-responsive materials, etc., will also be discussed.
{"title":"CHAPTER 9. Fused (Hetero)Cyclic Polymers Synthesized by Alkyne-Based Polymerizations","authors":"T. Han, J. Lam, B. Tang","doi":"10.1039/9781788016469-00264","DOIUrl":"https://doi.org/10.1039/9781788016469-00264","url":null,"abstract":"Fused (hetero)cyclic polymers are an important group of functional materials with unique electrochemical and photophysical properties. They are in great demand in high-tech applications such as organic electronics and advanced optical devices. Alkyne-based polymerizations have been found to be a powerful tool for the synthesis of fused (hetero)cyclic polymers. The fused (hetero)cyclic units can form in situ in the polymer backbones during the polymerizations. In this chapter, the progress in the synthesis of fused (hetero)cyclic polymers by alkyne-based polymerizations will be summarized, including the homopolymerizations of acetylenic monomers, stoichiometric polyannulations of internal diynes and aromatics, non-stoichiometric polyannulations of internal diynes and monofunctional aromatics, and multicomponent acetylenic polymerizations. Meanwhile, the properties and functionalities of the produced fused (hetero)cyclic polymers, such as thermal and morphological stability, light refraction and chromatic dispersion, photoluminescent properties, fluorescent chemosensor, external stimuli-responsive materials, etc., will also be discussed.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76069207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A series of group IV metal catalysts was designed by using the “Sidearm Strategy”. The sidearm group is envisioned to act as a controller of the shape and/or electronic properties of the catalytic site and so to tune the behaviours of olefin (co)polymerization. As expected, the coordination pattern of the newly-designed ligands with titanium tetrachloride leads to complexes of monoligand trichloro titanium, and this result makes the steric space of the active site for polymerization readily tunable via variation of the sidearm. In the presence of MMAO, these complexes show excellent activity to copolymerize ethylene and comonomer. 1-Alkenes, cycloolefins, ω-alkenol, ω-alkenoic acid, and ω-alkenoic ester could be incorporated into the PE backbone efficiently. In addition, both SHOP type nickel complexes and bisoxazolines were modified by the sidearm strategy. Based on this simple strategy, the activity of the resulting nickel complexes increased obviously and the newly-designed SaBOX played the key role in a highly syndiospecific (>90% rr) and controlled ATRP of methyl methacrylate (MMA), allyl methacrylate (AMA) and vinyl methacrylate (VMA) under mild polymerization conditions.
{"title":"CHAPTER 5. Olefin (Co)polymerizations Enabled by Catalyst Design Based on Sidearm Strategy","authors":"Jiao-Long Zhou, Xiao-Yan Wang, Xiu-Li Sun, Yong Tang","doi":"10.1039/9781788016469-00129","DOIUrl":"https://doi.org/10.1039/9781788016469-00129","url":null,"abstract":"A series of group IV metal catalysts was designed by using the “Sidearm Strategy”. The sidearm group is envisioned to act as a controller of the shape and/or electronic properties of the catalytic site and so to tune the behaviours of olefin (co)polymerization. As expected, the coordination pattern of the newly-designed ligands with titanium tetrachloride leads to complexes of monoligand trichloro titanium, and this result makes the steric space of the active site for polymerization readily tunable via variation of the sidearm. In the presence of MMAO, these complexes show excellent activity to copolymerize ethylene and comonomer. 1-Alkenes, cycloolefins, ω-alkenol, ω-alkenoic acid, and ω-alkenoic ester could be incorporated into the PE backbone efficiently. In addition, both SHOP type nickel complexes and bisoxazolines were modified by the sidearm strategy. Based on this simple strategy, the activity of the resulting nickel complexes increased obviously and the newly-designed SaBOX played the key role in a highly syndiospecific (>90% rr) and controlled ATRP of methyl methacrylate (MMA), allyl methacrylate (AMA) and vinyl methacrylate (VMA) under mild polymerization conditions.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73435182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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