Pub Date : 2024-07-09DOI: 10.1038/s44160-024-00592-8
David B. Ryffel, David Sarlah
Enantioselective hydrogenation is a stalwart reaction in synthetic chemistry. Now, hydrogenation of tetrasubstituted 1,2-dihydronaphthalene esters gives access to more than 30 cyclolignan natural products.
{"title":"Hydrogenation streamlines cyclolignan synthesis","authors":"David B. Ryffel, David Sarlah","doi":"10.1038/s44160-024-00592-8","DOIUrl":"10.1038/s44160-024-00592-8","url":null,"abstract":"Enantioselective hydrogenation is a stalwart reaction in synthetic chemistry. Now, hydrogenation of tetrasubstituted 1,2-dihydronaphthalene esters gives access to more than 30 cyclolignan natural products.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141574657","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 : 2024-07-05DOI: 10.1038/s44160-024-00614-5
Electrocatalytic synthesis of chemicals and fuels is seen as one way to decarbonize the chemicals industry. In this focus issue, we examine the electrochemical coupling of CO2 with heteroatoms for sustainable chemical synthesis.
{"title":"Electrosynthesis of C–X bonds from CO2","authors":"","doi":"10.1038/s44160-024-00614-5","DOIUrl":"10.1038/s44160-024-00614-5","url":null,"abstract":"Electrocatalytic synthesis of chemicals and fuels is seen as one way to decarbonize the chemicals industry. In this focus issue, we examine the electrochemical coupling of CO2 with heteroatoms for sustainable chemical synthesis.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44160-024-00614-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141546875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-03DOI: 10.1038/s44160-024-00611-8
Peter W. Seavill
{"title":"Oxidative coupling for urea synthesis","authors":"Peter W. Seavill","doi":"10.1038/s44160-024-00611-8","DOIUrl":"10.1038/s44160-024-00611-8","url":null,"abstract":"","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141546876","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}
Ordered heterostructured nanocrystals with large compositional and morphological diversity are important for many applications. However, design of multicomponent nanostructures at the atomic level is difficult due to the elusive nucleation and growth processes in a solution-phase environment. Here we report a modular synthetic protocol that produces ordered multilayered nanostructures with small particle size by layer-by-layer growth. We introduce a selenium capping agent to hinder self-assembly, aggregation and phase segregation of nanostructures, while also sequencing the priority of metal atoms that migrate in the substrate lattice according to different metal–selenium bonding strengths, leading to a layer-by-layer growth for ordered nanostructures. The multilayered multicomponent nanocrystals are demonstrated in an alkaline polymer electrolyte fuel cell by using PtRuZn-SKE (SKE, selenium-mediated Kirkendall effect) as the anodic hydrogen oxidation reaction catalyst, which can deliver a high peak power density of 1.52 W cm−2 in H2–O2 and 1.12 W cm−2 in H2–air (CO2-free) while operating at 600 mA cm−2 for 100 h. This generalizable strategy provides a predictable synthetic pathway to complex nanocrystals. A modular synthetic procedure is reported in which a selenium capping agent hinders phase segregation and aggregation while sequencing the priority of metals that migrate into the substrate lattice, leading to a layer-by-layer growth of ordered nanostructures.
具有大量成分和形态多样性的有序异质结构纳米晶体对许多应用都非常重要。然而，由于溶液相环境中难以捉摸的成核和生长过程，在原子水平上设计多组分纳米结构十分困难。在这里，我们报告了一种模块化合成方案，它能通过逐层生长产生小粒径的有序多层纳米结构。我们引入了一种硒封端剂，以阻碍纳米结构的自组装、聚集和相分离，同时还根据不同的金属硒键合强度对基底晶格中迁移的金属原子的优先级进行排序，从而实现有序纳米结构的逐层生长。通过使用 PtRuZn-SKE（SKE，硒介导的柯肯达尔效应）作为阳极氢氧化反应催化剂，在碱性聚合物电解质燃料电池中演示了多层多组分纳米晶体，该电池在 600 mA cm-2 下工作 100 小时，在 H2-O2 和 H2-air （无 CO2）中可提供 1.52 W cm-2 的高峰值功率密度。
{"title":"A selenium-mediated layer-by-layer synthetic strategy for multilayered multicomponent nanocrystals","authors":"Chun Hu, Yangyang Zhang, Renjie Ren, Jijian Xu, Lijia Liu, Qingyu Kong, Zhiwei Hu, Shijian Zheng, Lin Zhuang, Jian Huang, Yuanzhi Tan, Xiaoqing Huang","doi":"10.1038/s44160-024-00598-2","DOIUrl":"10.1038/s44160-024-00598-2","url":null,"abstract":"Ordered heterostructured nanocrystals with large compositional and morphological diversity are important for many applications. However, design of multicomponent nanostructures at the atomic level is difficult due to the elusive nucleation and growth processes in a solution-phase environment. Here we report a modular synthetic protocol that produces ordered multilayered nanostructures with small particle size by layer-by-layer growth. We introduce a selenium capping agent to hinder self-assembly, aggregation and phase segregation of nanostructures, while also sequencing the priority of metal atoms that migrate in the substrate lattice according to different metal–selenium bonding strengths, leading to a layer-by-layer growth for ordered nanostructures. The multilayered multicomponent nanocrystals are demonstrated in an alkaline polymer electrolyte fuel cell by using PtRuZn-SKE (SKE, selenium-mediated Kirkendall effect) as the anodic hydrogen oxidation reaction catalyst, which can deliver a high peak power density of 1.52 W cm−2 in H2–O2 and 1.12 W cm−2 in H2–air (CO2-free) while operating at 600 mA cm−2 for 100 h. This generalizable strategy provides a predictable synthetic pathway to complex nanocrystals. A modular synthetic procedure is reported in which a selenium capping agent hinders phase segregation and aggregation while sequencing the priority of metals that migrate into the substrate lattice, leading to a layer-by-layer growth of ordered nanostructures.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510596","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 : 2024-07-03DOI: 10.1038/s44160-024-00597-3
Wonseok Lee, Andrew M. Smith
Colloidal semiconductor nanocrystals based on CdSe have been precisely optimized for photonic applications in the visible spectrum, with modern products exhibiting structural uniformity, near 100% quantum yield and linewidths narrower than 100 meV. Here we report homogeneous nanocrystals with tunable bandgaps in the infrared spectrum based on HgSe and HgxCd1−xSe alloys deriving from CdSe precursors. We find that Ag+ catalyses cation interdiffusion to reduce the CdSe–HgSe alloying temperature from 250 °C to 80 °C. Together with ligands that modulate surface cation exchange rates, interdiffusion-enhanced Hg2+ exchange of diverse CdSe nanocrystals proceeds homogeneously and completely. The products retain the size, shape and uniformity of the parent nanocrystals but exhibit enhanced absorption. After passivation with heteroepitaxial CdZnS shells, photoluminescence wavelengths are tunable in the shortwave infrared by composition without changing size, with 80–91% quantum yield and linewidths near 100 meV. These materials may find applications in infrared photonic devices and infrared bioimaging. CdSe nanocrystals are used as synthetic templates for HgSe and alloyed HgxCd1−xSe nanocrystals with tunable, diverse structures. Cd2+-to-Hg2+ exchange occurs homogeneously and completely through interdiffusion enhancement with Ag+ catalysts and with surface cation exchange modulated by alkylthiol ligands.
{"title":"Interdiffusion-enhanced cation exchange for HgSe and HgCdSe nanocrystals with infrared bandgaps","authors":"Wonseok Lee, Andrew M. Smith","doi":"10.1038/s44160-024-00597-3","DOIUrl":"10.1038/s44160-024-00597-3","url":null,"abstract":"Colloidal semiconductor nanocrystals based on CdSe have been precisely optimized for photonic applications in the visible spectrum, with modern products exhibiting structural uniformity, near 100% quantum yield and linewidths narrower than 100 meV. Here we report homogeneous nanocrystals with tunable bandgaps in the infrared spectrum based on HgSe and HgxCd1−xSe alloys deriving from CdSe precursors. We find that Ag+ catalyses cation interdiffusion to reduce the CdSe–HgSe alloying temperature from 250 °C to 80 °C. Together with ligands that modulate surface cation exchange rates, interdiffusion-enhanced Hg2+ exchange of diverse CdSe nanocrystals proceeds homogeneously and completely. The products retain the size, shape and uniformity of the parent nanocrystals but exhibit enhanced absorption. After passivation with heteroepitaxial CdZnS shells, photoluminescence wavelengths are tunable in the shortwave infrared by composition without changing size, with 80–91% quantum yield and linewidths near 100 meV. These materials may find applications in infrared photonic devices and infrared bioimaging. CdSe nanocrystals are used as synthetic templates for HgSe and alloyed HgxCd1−xSe nanocrystals with tunable, diverse structures. Cd2+-to-Hg2+ exchange occurs homogeneously and completely through interdiffusion enhancement with Ag+ catalysts and with surface cation exchange modulated by alkylthiol ligands.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141530219","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 : 2024-07-02DOI: 10.1038/s44160-024-00591-9
Javier Guerrero-Morales, Marie Scaglia, Edouard Fauran, Guillaume Lepage, Shawn K. Collins
Macrolactones are privileged motifs in materials science, aromachemicals and pharmaceuticals. The pivotal ester linkage is often formed from chiral secondary alcohols, with macrolactonization using stoichiometric reagents to ensure retention or inversion of stereochemistry without compromising enantiopurity. An ideal strategy for macrolactonization is via dynamic kinetic resolution (DKR), which involves the simultaneous formation of the ester bond and introduction of a chiral centre with high stereocontrol. Surprisingly, a DKR method within the context of macrocyclization is yet to be reported. Here, using a chemoenzymatic approach, the macrocyclic DKR of seco esters affords enantioenriched macrolactones. An optimized protocol (using Candida antarctica lipase B (~0.04 mol%) and Shvo’s catalyst) forms 14–19-membered macrocycles with excellent enantioselectivities (85–99% e.e.). A variety of macrolactones were synthesized including aliphatic macrocycles, meta- and paracyclophanes as well as a macrodiolide via a dimerization protocol that was converted to the natural product macrolide (−)-pyrenophorin. The dynamic kinetic resolution of secondary alcohols for the synthesis of macrocycles is reported. This approach uses a chemoenzymatic method to form enantioenriched 14–19-membered macrolactones and macrodiolides and can be used to prepare bioactive natural products.
{"title":"Chemoenzymatic synthesis of macrocycles via dynamic kinetic resolution of secondary alcohols","authors":"Javier Guerrero-Morales, Marie Scaglia, Edouard Fauran, Guillaume Lepage, Shawn K. Collins","doi":"10.1038/s44160-024-00591-9","DOIUrl":"10.1038/s44160-024-00591-9","url":null,"abstract":"Macrolactones are privileged motifs in materials science, aromachemicals and pharmaceuticals. The pivotal ester linkage is often formed from chiral secondary alcohols, with macrolactonization using stoichiometric reagents to ensure retention or inversion of stereochemistry without compromising enantiopurity. An ideal strategy for macrolactonization is via dynamic kinetic resolution (DKR), which involves the simultaneous formation of the ester bond and introduction of a chiral centre with high stereocontrol. Surprisingly, a DKR method within the context of macrocyclization is yet to be reported. Here, using a chemoenzymatic approach, the macrocyclic DKR of seco esters affords enantioenriched macrolactones. An optimized protocol (using Candida antarctica lipase B (~0.04 mol%) and Shvo’s catalyst) forms 14–19-membered macrocycles with excellent enantioselectivities (85–99% e.e.). A variety of macrolactones were synthesized including aliphatic macrocycles, meta- and paracyclophanes as well as a macrodiolide via a dimerization protocol that was converted to the natural product macrolide (−)-pyrenophorin. The dynamic kinetic resolution of secondary alcohols for the synthesis of macrocycles is reported. This approach uses a chemoenzymatic method to form enantioenriched 14–19-membered macrolactones and macrodiolides and can be used to prepare bioactive natural products.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510597","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 : 2024-07-01DOI: 10.1038/s44160-024-00593-7
Matthias M. Waegele
The energy efficiency and product selectivity of ethylene electrosynthesis from CO is improved by accelerating water dissociation.
通过加速水的解离，提高了以一氧化碳为原料进行乙烯电合成的能效和产品选择性。
{"title":"Efficient ethylene electrosynthesis by accelerating water dissociation","authors":"Matthias M. Waegele","doi":"10.1038/s44160-024-00593-7","DOIUrl":"10.1038/s44160-024-00593-7","url":null,"abstract":"The energy efficiency and product selectivity of ethylene electrosynthesis from CO is improved by accelerating water dissociation.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510599","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 : 2024-07-01DOI: 10.1038/s44160-024-00566-w
Jiale Xie, Jiayu Zhang, Sitthichok Kasemthaveechok, Sara López-Resano, Eric Cots, Feliu Maseras, Mónica H. Pérez-Temprano
Intramolecular amination of remote aliphatic C–H bonds via hydrogen-atom transfer reactions has become a powerful tool for accessing saturated nitrogen-containing heterocycles. However, the formation of six-membered rings or oxa-heterocycles remains a formidable challenge for Hofmann–Löffler–Freytag reactions. Here we show how by simply combining bench-stable (bis(trifluoroacetoxy)iodo)benzene and hexafluoroisopropanol (HFIP) we can switch from the well-established Hofmann–Löffler–Freytag mechanism to a different versatile reaction pathway that enables selective C(sp3)–H bond functionalization. We have exploited the facile formation of radical cations via single-electron transfer, in the presence or absence of light, to synthesize pyrrolidines and piperidines, including drug-type molecules, along with O-heterocycles. Experimental and computational mechanistic studies support two distinct mechanistic pathways, depending on the electron density of the substrate, in which the HFIP plays a multifunctional role. Saturated heterocycles are prevalent motifs in organic synthesis but their synthesis still presents persistent challenges. Now, a hypervalent iodine(III)-mediated selective intramolecular C(sp3)–H functionalization, facilitated by hexafluoroisopropanol, is reported, which via single-electron transfer provides access to pyrrolidines, piperidines and O-heterocycles in the presence or absence of light.
{"title":"Hexafluoroisopropanol-assisted selective intramolecular synthesis of heterocycles by single-electron transfer","authors":"Jiale Xie, Jiayu Zhang, Sitthichok Kasemthaveechok, Sara López-Resano, Eric Cots, Feliu Maseras, Mónica H. Pérez-Temprano","doi":"10.1038/s44160-024-00566-w","DOIUrl":"10.1038/s44160-024-00566-w","url":null,"abstract":"Intramolecular amination of remote aliphatic C–H bonds via hydrogen-atom transfer reactions has become a powerful tool for accessing saturated nitrogen-containing heterocycles. However, the formation of six-membered rings or oxa-heterocycles remains a formidable challenge for Hofmann–Löffler–Freytag reactions. Here we show how by simply combining bench-stable (bis(trifluoroacetoxy)iodo)benzene and hexafluoroisopropanol (HFIP) we can switch from the well-established Hofmann–Löffler–Freytag mechanism to a different versatile reaction pathway that enables selective C(sp3)–H bond functionalization. We have exploited the facile formation of radical cations via single-electron transfer, in the presence or absence of light, to synthesize pyrrolidines and piperidines, including drug-type molecules, along with O-heterocycles. Experimental and computational mechanistic studies support two distinct mechanistic pathways, depending on the electron density of the substrate, in which the HFIP plays a multifunctional role. Saturated heterocycles are prevalent motifs in organic synthesis but their synthesis still presents persistent challenges. Now, a hypervalent iodine(III)-mediated selective intramolecular C(sp3)–H functionalization, facilitated by hexafluoroisopropanol, is reported, which via single-electron transfer provides access to pyrrolidines, piperidines and O-heterocycles in the presence or absence of light.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s44160-024-00566-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1038/s44160-024-00596-4
Qing-Qing Zeng, Qian-Yi Zhou, Carla Calvó-Tusell, Shuang-Yu Dai, Xiang Zhao, Marc Garcia-Borràs, Zhen Liu
Efficient methods for achieving desaturation of carbonyl compounds are highly sought after in organic chemistry. In contrast to synthetic approaches, enzymatic desaturation systems offer the potential to enhance sustainability and selectivity but have remained elusive. Here we report the development of an enzymatic desaturation system based on flavin-dependent ene-reductases for desymmetrizing cyclohexanones. This platform facilitates the synthesis of a wide array of chiral cyclohexenones bearing quaternary stereocentres—structural motifs commonly present in bioactive molecules—with excellent yields and enantioselectivities. Experimental and computational mechanistic studies reveal the roles of key active-site residues that enable the formation and stabilization of an enolate intermediate in the desaturation event. Additionally, by leveraging these insights, we have devised a biocatalytic strategy for the synthesis of enones by reductively desymmetrizing cyclohexadienones. This method yields the opposite enantiomer compared to our desaturation system, underscoring the enantiodivergence and broad applicability of our flavin-based desymmetrization approaches. Biocatalytic methods for the synthesis of chiral cyclohexenones bearing quaternary stereocentres through oxidation and reduction reactions are reported. Mechanistic studies reveal the role of active-site residues in the oxidation process and inform the development of the enzymatic reduction reaction.
{"title":"Biocatalytic desymmetrization for synthesis of chiral enones using flavoenzymes","authors":"Qing-Qing Zeng, Qian-Yi Zhou, Carla Calvó-Tusell, Shuang-Yu Dai, Xiang Zhao, Marc Garcia-Borràs, Zhen Liu","doi":"10.1038/s44160-024-00596-4","DOIUrl":"10.1038/s44160-024-00596-4","url":null,"abstract":"Efficient methods for achieving desaturation of carbonyl compounds are highly sought after in organic chemistry. In contrast to synthetic approaches, enzymatic desaturation systems offer the potential to enhance sustainability and selectivity but have remained elusive. Here we report the development of an enzymatic desaturation system based on flavin-dependent ene-reductases for desymmetrizing cyclohexanones. This platform facilitates the synthesis of a wide array of chiral cyclohexenones bearing quaternary stereocentres—structural motifs commonly present in bioactive molecules—with excellent yields and enantioselectivities. Experimental and computational mechanistic studies reveal the roles of key active-site residues that enable the formation and stabilization of an enolate intermediate in the desaturation event. Additionally, by leveraging these insights, we have devised a biocatalytic strategy for the synthesis of enones by reductively desymmetrizing cyclohexadienones. This method yields the opposite enantiomer compared to our desaturation system, underscoring the enantiodivergence and broad applicability of our flavin-based desymmetrization approaches. Biocatalytic methods for the synthesis of chiral cyclohexenones bearing quaternary stereocentres through oxidation and reduction reactions are reported. Mechanistic studies reveal the role of active-site residues in the oxidation process and inform the development of the enzymatic reduction reaction.","PeriodicalId":74251,"journal":{"name":"Nature synthesis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510614","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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