Nature MaterialsPub Date : 2024-09-12DOI: 10.1038/s41563-024-02004-w
Tianyu Huang, Qi Wang, Hai Zhang, Yangyang Xin, Yuewei Zhang, Xiankai Chen, Dongdong Zhang, Lian Duan
{"title":"Delocalizing electron distribution in thermally activated delayed fluorophors for high-efficiency and long-lifetime blue electroluminescence","authors":"Tianyu Huang, Qi Wang, Hai Zhang, Yangyang Xin, Yuewei Zhang, Xiankai Chen, Dongdong Zhang, Lian Duan","doi":"10.1038/s41563-024-02004-w","DOIUrl":"10.1038/s41563-024-02004-w","url":null,"abstract":"Blue thermally activated delayed fluorescent emitters are promising for the next generation of organic light-emitting diodes, yet their performance still cannot meet the requirements for commercialization. Here we establish a design rule for highly efficient and stable thermally activated delayed fluorescent emitters by introducing an auxiliary acceptor that could delocalize electron distributions, enhancing molecular stability in both the negative polaron and triplet excited state, while also accelerating triplet-to-singlet up-conversion and singlet radiative processes simultaneously. Proof-of-concept thermally activated delayed fluorescent compounds, based on a multi-carbazole-benzonitrile structure, exhibit near-unity photoluminescent quantum yields, short-lived delays and improved photoluminescent and electroluminescent stabilities. A deep-blue organic light-emitting diode using one of these molecules as a sensitizer for a multi-resonance emitter achieves a remarkable time to 95% of initial luminance of 221 h at an initial luminance of 1,000 cd m−2, a maximum external quantum efficiency of 30.8% and Commission Internationale de l’Eclairage coordinates of (0.14, 0.17). The stability and efficiency of thermally activated delayed fluorescent (TADF) emitters are still limited. Here the authors design TADF compounds by introducing an auxiliary acceptor with both enhanced stability and enhanced efficiency.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 11","pages":"1523-1530"},"PeriodicalIF":37.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-09-11DOI: 10.1038/s41563-024-02007-7
Qingkun Liu, Wei Wang, Himani Sinhmar, Itay Griniasty, Jason Z. Kim, Jacob T. Pelster, Paragkumar Chaudhari, Michael F. Reynolds, Michael C. Cao, David A. Muller, Alyssa B. Apsel, Nicholas L. Abbott, Hadas Kress-Gazit, Paul L. McEuen, Itai Cohen
{"title":"Electronically configurable microscopic metasheet robots","authors":"Qingkun Liu, Wei Wang, Himani Sinhmar, Itay Griniasty, Jason Z. Kim, Jacob T. Pelster, Paragkumar Chaudhari, Michael F. Reynolds, Michael C. Cao, David A. Muller, Alyssa B. Apsel, Nicholas L. Abbott, Hadas Kress-Gazit, Paul L. McEuen, Itai Cohen","doi":"10.1038/s41563-024-02007-7","DOIUrl":"https://doi.org/10.1038/s41563-024-02007-7","url":null,"abstract":"<p>Shape morphing is vital to locomotion in microscopic organisms but has been challenging to achieve in sub-millimetre robots. By overcoming obstacles associated with miniaturization, we demonstrate microscopic electronically configurable morphing metasheet robots. These metabots expand locally using a kirigami structure spanning five decades in length, from 10 nm electrochemically actuated hinges to 100 μm splaying panels making up the ~1 mm robot. The panels are organized into unit cells that can expand and contract by 40% within 100 ms. These units are tiled to create metasheets with over 200 hinges and independent electronically actuating regions that enable the robot to switch between multiple target geometries with distinct curvature distributions. By electronically actuating independent regions with prescribed phase delays, we generate locomotory gaits. These results advance a metamaterial paradigm for microscopic, continuum, compliant, programmable robots and pave the way to a broad spectrum of applications, including reconfigurable micromachines, tunable optical metasurfaces and miniaturized biomedical devices.</p>","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"25 1","pages":""},"PeriodicalIF":41.2,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-09-10DOI: 10.1038/s41563-024-01993-y
Niels C. H. Hesp, Sergi Batlle-Porro, Roshan Krishna Kumar, Hitesh Agarwal, David Barcons Ruiz, Hanan Herzig Sheinfux, Kenji Watanabe, Takashi Taniguchi, Petr Stepanov, Frank H. L. Koppens
{"title":"Cryogenic nano-imaging of second-order moiré superlattices","authors":"Niels C. H. Hesp, Sergi Batlle-Porro, Roshan Krishna Kumar, Hitesh Agarwal, David Barcons Ruiz, Hanan Herzig Sheinfux, Kenji Watanabe, Takashi Taniguchi, Petr Stepanov, Frank H. L. Koppens","doi":"10.1038/s41563-024-01993-y","DOIUrl":"10.1038/s41563-024-01993-y","url":null,"abstract":"Second-order superlattices form when moiré superlattices with similar periodicities interfere with each other, leading to larger superlattice periodicities. These crystalline structures are engineered using two-dimensional materials such as graphene and hexagonal boron nitride, and the specific alignment plays a crucial role in facilitating correlation-driven topological phases. Signatures of second-order superlattices have been identified in magnetotransport experiments; however, real-space visualization is still lacking. Here we reveal the second-order superlattice in magic-angle twisted bilayer graphene closely aligned with hexagonal boron nitride through electronic transport measurements and cryogenic nanoscale photovoltage measurements and evidenced by long-range periodic photovoltage modulations. Our results show that even minuscule strain and twist-angle variations as small as 0.01° can lead to drastic changes in the second-order superlattice structure. Our real-space observations, therefore, serve as a ‘magnifying glass’ for strain and twist angle and can elucidate the mechanisms responsible for the breaking of spatial symmetries in twisted bilayer graphene. Second-order superlattices emerging in magic-angle twisted bilayer graphene aligned with hexagonal boron nitride are visualized in real space through cryogenic nano-imaging, revealing the impact of strain and twist-angle variations.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 12","pages":"1664-1670"},"PeriodicalIF":37.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142160576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Towards the scalable synthesis of two-dimensional heterostructures and superlattices beyond exfoliation and restacking","authors":"Jia Li, Xiangdong Yang, Zhengwei Zhang, Weiyou Yang, Xidong Duan, Xiangfeng Duan","doi":"10.1038/s41563-024-01989-8","DOIUrl":"10.1038/s41563-024-01989-8","url":null,"abstract":"Two-dimensional transition metal dichalcogenides, which feature atomically thin geometry and dangling-bond-free surfaces, have attracted intense interest for diverse technology applications, including ultra-miniaturized transistors towards the subnanometre scale. A straightforward exfoliation-and-restacking approach has been widely used for nearly arbitrary assembly of diverse two-dimensional (2D) heterostructures, superlattices and moiré superlattices, providing a versatile materials platform for fundamental investigations of exotic physical phenomena and proof-of-concept device demonstrations. While this approach has contributed importantly to the recent flourishing of 2D materials research, it is clearly unsuitable for practical technologies. Capturing the full potential of 2D transition metal dichalcogenides requires robust and scalable synthesis of these atomically thin materials and their heterostructures with designable spatial modulation of chemical compositions and electronic structures. The extreme aspect ratio, lack of intrinsic substrate and highly delicate nature of the atomically thin crystals present fundamental difficulties in material synthesis. Here we summarize the key challenges, highlight current advances and outline opportunities in the scalable synthesis of transition metal dichalcogenide-based heterostructures, superlattices and moiré superlattices. The practical application of 2D transition metal dichalcogenides (TMDs) requires robust and scalable synthesis of these atomically thin materials and their heterostructures. This Review discusses the key challenges, current progress and opportunities in the controllable synthesis of TMD-based heterostructures, superlattices and moiré superlattices.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 10","pages":"1326-1338"},"PeriodicalIF":37.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-09-03DOI: 10.1038/s41563-024-01998-7
Rui Zeng, Huiqi Li, Zixiao Shi, Lang Xu, Jinhui Meng, Weixuan Xu, Hongsen Wang, Qihao Li, Christopher J. Pollock, Tianquan Lian, Manos Mavrikakis, David A. Muller, Héctor D. Abruña
{"title":"Origins of enhanced oxygen reduction activity of transition metal nitrides","authors":"Rui Zeng, Huiqi Li, Zixiao Shi, Lang Xu, Jinhui Meng, Weixuan Xu, Hongsen Wang, Qihao Li, Christopher J. Pollock, Tianquan Lian, Manos Mavrikakis, David A. Muller, Héctor D. Abruña","doi":"10.1038/s41563-024-01998-7","DOIUrl":"10.1038/s41563-024-01998-7","url":null,"abstract":"Transition metal nitride (TMN-) based materials have recently emerged as promising non-precious-metal-containing electrocatalysts for the oxygen reduction reaction (ORR) in alkaline media. However, the lack of fundamental understanding of the oxide surface has limited insights into structure–(re)activity relationships and rational catalyst design. Here we demonstrate how a well-defined TMN can dictate/control the as-formed oxide surface and the resulting ORR electrocatalytic activity. Structural characterization of MnN nanocuboids revealed that an electrocatalytically active Mn3O4 shell grew epitaxially on the MnN core, with an expansive strain along the [010] direction to the surface Mn3O4. The strained Mn3O4 shell on the MnN core exhibited an intrinsic activity that was over 300% higher than that of pure Mn3O4. A combined electrochemical and computational investigation indicated/suggested that the enhancement probably originates from a more hydroxylated oxide surface resulting from the expansive strain. This work establishes a clear and definitive atomistic picture of the nitride/oxide interface and provides a comprehensive mechanistic understanding of the structure–reactivity relationship in TMNs, critical for other catalytic interfaces for different electrochemical processes. While transition metal nitrides are promising low-cost electrocatalysts for the oxygen reduction reaction in alkaline media, a fundamental understanding of their activity is still lacking. Here MnN nanocuboids with well-defined surface structures are investigated, providing atomistic insight and mechanistic understanding.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 12","pages":"1695-1703"},"PeriodicalIF":37.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-09-02DOI: 10.1038/s41563-024-01961-6
Ningqiang Gong, Wenqun Zhong, Mohamad-Gabriel Alameh, Xuexiang Han, Lulu Xue, Rakan El-Mayta, Gan Zhao, Andrew E. Vaughan, Zhiyuan Qin, Fengyuan Xu, Alex G. Hamilton, Dongyoon Kim, Junchao Xu, Junhyong Kim, Xucong Teng, Jinghong Li, Xing-Jie Liang, Drew Weissman, Wei Guo, Michael J. Mitchell
{"title":"Tumour-derived small extracellular vesicles act as a barrier to therapeutic nanoparticle delivery","authors":"Ningqiang Gong, Wenqun Zhong, Mohamad-Gabriel Alameh, Xuexiang Han, Lulu Xue, Rakan El-Mayta, Gan Zhao, Andrew E. Vaughan, Zhiyuan Qin, Fengyuan Xu, Alex G. Hamilton, Dongyoon Kim, Junchao Xu, Junhyong Kim, Xucong Teng, Jinghong Li, Xing-Jie Liang, Drew Weissman, Wei Guo, Michael J. Mitchell","doi":"10.1038/s41563-024-01961-6","DOIUrl":"10.1038/s41563-024-01961-6","url":null,"abstract":"Nanoparticles are promising for drug delivery applications, with several clinically approved products. However, attaining high nanoparticle accumulation in solid tumours remains challenging. Here we show that tumour cell-derived small extracellular vesicles (sEVs) block nanoparticle delivery to tumours, unveiling another barrier to nanoparticle-based tumour therapy. Tumour cells secrete large amounts of sEVs in the tumour microenvironment, which then bind to nanoparticles entering tumour tissue and traffic them to liver Kupffer cells for degradation. Knockdown of Rab27a, a gene that controls sEV secretion, decreases sEV levels and improves nanoparticle accumulation in tumour tissue. The therapeutic efficacy of messenger RNAs encoding tumour suppressing and proinflammatory proteins is greatly improved when co-encapsulated with Rab27a small interfering RNA in lipid nanoparticles. Together, our results demonstrate that tumour cell-derived sEVs act as a defence system against nanoparticle tumour delivery and that this system may be a potential target for improving nanoparticle-based tumour therapies. Cancer cell-derived small extracellular vesicles bind to therapeutic nanoparticles leading them from tumours to the liver for degradation. This mechanism is another barrier for the development of efficient nanoparticle-based cancer therapies.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 12","pages":"1736-1747"},"PeriodicalIF":37.2,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142118054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-09-02DOI: 10.1038/s41563-024-01997-8
Jie Shi, Toshinari Koketsu, Zhenglu Zhu, Menghao Yang, Lijun Sui, Jie Liu, Mingxue Tang, Zhe Deng, Mengyi Liao, Jingwei Xiang, Yue Shen, Long Qie, Yunhui Huang, Peter Strasser, Jiwei Ma
{"title":"In situ p-block protective layer plating in carbonate-based electrolytes enables stable cell cycling in anode-free lithium batteries","authors":"Jie Shi, Toshinari Koketsu, Zhenglu Zhu, Menghao Yang, Lijun Sui, Jie Liu, Mingxue Tang, Zhe Deng, Mengyi Liao, Jingwei Xiang, Yue Shen, Long Qie, Yunhui Huang, Peter Strasser, Jiwei Ma","doi":"10.1038/s41563-024-01997-8","DOIUrl":"10.1038/s41563-024-01997-8","url":null,"abstract":"‘Anode-free’ Li metal batteries offer the highest possible energy density but face low Li coulombic efficiency when operated in carbonate electrolytes. Here we report a performance improvement of anode-free Li metal batteries using p-block tin octoate additive in the carbonate electrolyte. We show that the preferential adsorption of the octoate moiety on the Cu substrate induces the construction of a carbonate-less protective layer, which inhibits the side reactions and contributes to the uniform Li plating. In the mean time, the reduction of Sn2+ at the initial charging process builds a stable lithophilic layer of Cu6Sn5 alloy and Sn, improving the affinity between the Li and the Cu substrate. Notably, anode-free Li metal pouch cells with tin octoate additive demonstrate good cycling stability with a high coulombic efficiency of ~99.1%. Furthermore, this in situ p-block layer plating strategy is also demonstrated with other types of p-block metal octoate, as well as a Na metal battery system, demonstrating the high level of universality. A p-block metal octoate additive in carbonate electrolytes enables the reversible plating/stripping of alkali metal in anode-free batteries by forming a protective layer with a preferentially adsorbed octoate moiety and uniformly plated p-block metal.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 12","pages":"1686-1694"},"PeriodicalIF":37.2,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142118047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-08-30DOI: 10.1038/s41563-024-01973-2
{"title":"A general strategy for the vitrification of monatomic metals","authors":"","doi":"10.1038/s41563-024-01973-2","DOIUrl":"10.1038/s41563-024-01973-2","url":null,"abstract":"The question of whether all materials can be put into glass form was raised half a century ago but has remained unanswered. Using picosecond pulsed laser ablation, the vitrification of gold — which has been notoriously difficult — and several other monatomic metals is demonstrated, indicating that vitrification is an intrinsic property of matter.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 9","pages":"1165-1166"},"PeriodicalIF":37.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-08-30DOI: 10.1038/s41563-024-01951-8
Luojun Du, Zhiheng Huang, Jin Zhang, Fangwei Ye, Qing Dai, Hui Deng, Guangyu Zhang, Zhipei Sun
{"title":"Nonlinear physics of moiré superlattices","authors":"Luojun Du, Zhiheng Huang, Jin Zhang, Fangwei Ye, Qing Dai, Hui Deng, Guangyu Zhang, Zhipei Sun","doi":"10.1038/s41563-024-01951-8","DOIUrl":"10.1038/s41563-024-01951-8","url":null,"abstract":"Nonlinear physics is one of the most important research fields in modern physics and materials science. It offers an unprecedented paradigm for exploring many fascinating physical phenomena and realizing diverse cutting-edge applications inconceivable in the framework of linear processes. Here we review the recent theoretical and experimental progress concerning the nonlinear physics of synthetic quantum moiré superlattices. We focus on the emerging nonlinear electronic, optical and optoelectronic properties of moiré superlattices, including but not limited to the nonlinear anomalous Hall effect, dynamically twistable harmonic generation, nonlinear optical chirality, ultralow-power-threshold optical solitons and spontaneous photogalvanic effect. We also present our perspectives on the future opportunities and challenges in this rapidly progressing field, and highlight the implications for advances in both fundamental physics and technological innovations. This Review introduces emerging nonlinear electronic, optical and optoelectronic properties of moiré superlattices and discusses opportunities and challenges in this rapidly progressing field, as well as implications for fundamental physics and technological innovations.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 9","pages":"1179-1192"},"PeriodicalIF":37.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature MaterialsPub Date : 2024-08-30DOI: 10.1038/s41563-024-01950-9
Mourad Oudich, Xianghong Kong, Tan Zhang, Chengwei Qiu, Yun Jing
{"title":"Engineered moiré photonic and phononic superlattices","authors":"Mourad Oudich, Xianghong Kong, Tan Zhang, Chengwei Qiu, Yun Jing","doi":"10.1038/s41563-024-01950-9","DOIUrl":"10.1038/s41563-024-01950-9","url":null,"abstract":"Recent discoveries of Mott insulating and unconventional superconducting states in twisted bilayer graphene with moiré superlattices have not only reshaped the landscape of ‘twistronics’ but also sparked the rapidly growing fields of moiré photonic and phononic structures. These innovative moiré structures have opened new routes of exploration for classical wave physics, leading to intriguing phenomena and robust control of electromagnetic and mechanical waves. Drawing inspiration from the success of twisted bilayer graphene, this Perspective describes an overarching framework of the emerging moiré photonic and phononic structures that promise novel classical wave devices. We begin with the fundamentals of moiré superlattices, before highlighting recent studies that exploit twist angle and interlayer coupling as new ingredients with which to engineer and tailor the band structures and effective material properties of photonic and phononic structures. Finally, we discuss the future directions and prospects of this emerging area in materials science and wave physics. Platforms that exhibit moiré patterns have the potential to tailor band structures and control electromagnetic and mechanical waves. This Perspective discusses the current state of the art, challenges and outlook within the realm of classical wave physics.","PeriodicalId":19058,"journal":{"name":"Nature Materials","volume":"23 9","pages":"1169-1178"},"PeriodicalIF":37.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}