Daichao Wu, Rui Yin, Guodong Chen, Helder V. Ribeiro-Filho, Melyssa Cheung, Paul F. Robbins, Roy A. Mariuzza, Brian G. Pierce
T cell receptors (TCRs) that recognize cancer neoantigens are important for anticancer immune responses and immunotherapy. Understanding the structural basis of TCR recognition of neoantigens provides insights into their exquisite specificity and can enable design of optimized TCRs. We determined crystal structures of a human TCR in complex with NRAS Q61K and Q61R neoantigen peptides and HLA-A1 major histocompatibility complex (MHC), revealing the molecular underpinnings for dual recognition and specificity versus wild-type NRAS peptide. We then used multiple versions of AlphaFold to model the corresponding complex structures, given the challenge of immune recognition for such methods. One implementation of AlphaFold2 (TCRmodel2) with additional sampling was able to generate accurate models of the complexes, while AlphaFold3 also showed strong performance, although success was lower for other complexes. This study provides insights into TCR recognition of a shared cancer neoantigen as well as the utility and practical considerations for using AlphaFold to model TCR-peptide-MHC complexes.
{"title":"Structural characterization and AlphaFold modeling of human T cell receptor recognition of NRAS cancer neoantigens","authors":"Daichao Wu, Rui Yin, Guodong Chen, Helder V. Ribeiro-Filho, Melyssa Cheung, Paul F. Robbins, Roy A. Mariuzza, Brian G. Pierce","doi":"10.1126/sciadv.adq6150","DOIUrl":"10.1126/sciadv.adq6150","url":null,"abstract":"<div >T cell receptors (TCRs) that recognize cancer neoantigens are important for anticancer immune responses and immunotherapy. Understanding the structural basis of TCR recognition of neoantigens provides insights into their exquisite specificity and can enable design of optimized TCRs. We determined crystal structures of a human TCR in complex with NRAS Q61K and Q61R neoantigen peptides and HLA-A1 major histocompatibility complex (MHC), revealing the molecular underpinnings for dual recognition and specificity versus wild-type NRAS peptide. We then used multiple versions of AlphaFold to model the corresponding complex structures, given the challenge of immune recognition for such methods. One implementation of AlphaFold2 (TCRmodel2) with additional sampling was able to generate accurate models of the complexes, while AlphaFold3 also showed strong performance, although success was lower for other complexes. This study provides insights into TCR recognition of a shared cancer neoantigen as well as the utility and practical considerations for using AlphaFold to model TCR-peptide-MHC complexes.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11584006/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142693546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Endoluminal and endocavitary intervention via natural orifices of the body is an emerging trend in medicine, further underpinning the future of early intervention and precision surgery. This motivates the development of small continuum robots to navigate freely in confined and tortuous environment. The trade-off between a large range of motion and high precision with concomitant actuation cross-talk poses a major challenge. Here, we present a submillimeter-scale fiber robot (~1 mm) capable of decoupled macro and micro manipulations for intervention and operation. The thin optical fibers, working both as mechanical tendons and light waveguides, can be pulled/pushed to actuate the macro tendon-driven continuum robot and transmit light to actuate the liquid crystal elastomer–based micro built-in light-driven parallel robot. The combination of the decoupled macro and micro motions can accomplish accurate cross-scale motion from several millimeters down to tens of micrometers. In vivo animal studies are performed to demonstrate its positioning accuracy of precise micro operations in endoluminal or endocavitary intervention.
{"title":"Submillimeter fiber robots capable of decoupled macro-micro motion for endoluminal manipulation","authors":"Cheng Zhou, Zheng Xu, Zecai Lin, Xiaotong Qin, Jingyuan Xia, Xiaojie Ai, Chuqian Lou, Ziyi Huang, Shaoping Huang, Huanghua Liu, Yun Zou, Weidong Chen, Guang-Zhong Yang, Anzhu Gao","doi":"10.1126/sciadv.adr6428","DOIUrl":"10.1126/sciadv.adr6428","url":null,"abstract":"<div >Endoluminal and endocavitary intervention via natural orifices of the body is an emerging trend in medicine, further underpinning the future of early intervention and precision surgery. This motivates the development of small continuum robots to navigate freely in confined and tortuous environment. The trade-off between a large range of motion and high precision with concomitant actuation cross-talk poses a major challenge. Here, we present a submillimeter-scale fiber robot (~1 mm) capable of decoupled macro and micro manipulations for intervention and operation. The thin optical fibers, working both as mechanical tendons and light waveguides, can be pulled/pushed to actuate the macro tendon-driven continuum robot and transmit light to actuate the liquid crystal elastomer–based micro built-in light-driven parallel robot. The combination of the decoupled macro and micro motions can accomplish accurate cross-scale motion from several millimeters down to tens of micrometers. In vivo animal studies are performed to demonstrate its positioning accuracy of precise micro operations in endoluminal or endocavitary intervention.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11584019/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142693547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Charles Bayly-Jones, Christopher J. Lupton, Laura D’Andrea, Yong-Gang Chang, Gareth D. Jones, Joel R. Steele, Hari Venugopal, Ralf B. Schittenhelm, Michelle L. Halls, Andrew M. Ellisdon
Tuberous sclerosis complex (TSC) is targeted to the lysosomal membrane, where it hydrolyzes RAS homolog–mTORC1 binding (RHEB) from its GTP-bound to GDP-bound state, inhibiting mechanistic target of rapamycin complex 1 (mTORC1). Loss-of-function mutations in TSC cause TSC disease, marked by excessive tumor growth. Here, we overcome a high degree of continuous conformational heterogeneity to determine the 2.8-Å cryo–electron microscopy (cryo-EM) structure of the complete human TSC in complex with the lysosomal recruitment factor WD repeat domain phosphoinositide–interacting protein 3 (WIPI3). We discover a previously undetected amino-terminal TSC1 HEAT repeat dimer that clamps onto a single TSC wing and forms a phosphatidylinositol phosphate (PIP)–binding pocket, which specifically binds monophosphorylated PIPs. These structural advances provide a model by which WIPI3 and PIP-signaling networks coordinate to recruit TSC to the lysosomal membrane to inhibit mTORC1. The high-resolution TSC structure reveals previously unrecognized mutational hotspots and uncovers crucial insights into the mechanisms of TSC dysregulation in disease.
{"title":"Structure of the human TSC:WIPI3 lysosomal recruitment complex","authors":"Charles Bayly-Jones, Christopher J. Lupton, Laura D’Andrea, Yong-Gang Chang, Gareth D. Jones, Joel R. Steele, Hari Venugopal, Ralf B. Schittenhelm, Michelle L. Halls, Andrew M. Ellisdon","doi":"10.1126/sciadv.adr5807","DOIUrl":"10.1126/sciadv.adr5807","url":null,"abstract":"<div >Tuberous sclerosis complex (TSC) is targeted to the lysosomal membrane, where it hydrolyzes RAS homolog–mTORC1 binding (RHEB) from its GTP-bound to GDP-bound state, inhibiting mechanistic target of rapamycin complex 1 (mTORC1). Loss-of-function mutations in TSC cause TSC disease, marked by excessive tumor growth. Here, we overcome a high degree of continuous conformational heterogeneity to determine the 2.8-Å cryo–electron microscopy (cryo-EM) structure of the complete human TSC in complex with the lysosomal recruitment factor WD repeat domain phosphoinositide–interacting protein 3 (WIPI3). We discover a previously undetected amino-terminal TSC1 HEAT repeat dimer that clamps onto a single TSC wing and forms a phosphatidylinositol phosphate (PIP)–binding pocket, which specifically binds monophosphorylated PIPs. These structural advances provide a model by which WIPI3 and PIP-signaling networks coordinate to recruit TSC to the lysosomal membrane to inhibit mTORC1. The high-resolution TSC structure reveals previously unrecognized mutational hotspots and uncovers crucial insights into the mechanisms of TSC dysregulation in disease.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578170/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142681519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laura Rijns, Martin G. T. A. Rutten, Riccardo Bellan, Hongbo Yuan, Mauro L. Mugnai, Susana Rocha, Emanuela del Gado, Paul H. J. Kouwer, Patricia Y. W. Dankers
Nature uses discrete molecular building blocks to form polymers that assemble into multicomponent, multi-dynamic networks, inside (cytoskeleton) and outside (extracellular matrix) the cell. Both the intra-fibrous molecular dynamics and interactions between fibers dictate (non)linear mechanics, such as stress stiffening and relaxation, and ultimately biological function. Current synthetic systems capture only one dynamic process. Here, we present multi-dynamic hydrogels by uniting a stress-stiffening polymer with supramolecular polymers. Crucial is the molecular dynamics of the supramolecular polymers: They dictate the interaction strength with the stress-stiffening polymer and the subsequent dynamic mechanical properties of the mixed networks. The biological relevance of our multi-dynamic hydrogels is demonstrated by their ability to support fibroblast cell spreading. Future work may address the display of various dynamically presented bioactive cues to cells.
{"title":"Synthetic, multi-dynamic hydrogels by uniting stress-stiffening and supramolecular polymers","authors":"Laura Rijns, Martin G. T. A. Rutten, Riccardo Bellan, Hongbo Yuan, Mauro L. Mugnai, Susana Rocha, Emanuela del Gado, Paul H. J. Kouwer, Patricia Y. W. Dankers","doi":"10.1126/sciadv.adr3209","DOIUrl":"10.1126/sciadv.adr3209","url":null,"abstract":"<div >Nature uses discrete molecular building blocks to form polymers that assemble into multicomponent, multi-dynamic networks, inside (cytoskeleton) and outside (extracellular matrix) the cell. Both the intra-fibrous molecular dynamics and interactions between fibers dictate (non)linear mechanics, such as stress stiffening and relaxation, and ultimately biological function. Current synthetic systems capture only one dynamic process. Here, we present multi-dynamic hydrogels by uniting a stress-stiffening polymer with supramolecular polymers. Crucial is the molecular dynamics of the supramolecular polymers: They dictate the interaction strength with the stress-stiffening polymer and the subsequent dynamic mechanical properties of the mixed networks. The biological relevance of our multi-dynamic hydrogels is demonstrated by their ability to support fibroblast cell spreading. Future work may address the display of various dynamically presented bioactive cues to cells.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.science.org/doi/reader/10.1126/sciadv.adr3209","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142681527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shuaishuai Yang, Na Li, Enyue Zhao, Chengzhi Wang, Jingxin He, Xiong Xiao, Debao Fang, Qing Ni, Xile Han, Xiaobin Xue, Lai Chen, Ning Li, Jingbo Li, Tuan Guo, Yuefeng Su, Haibo Jin
Dendrite growth in solid-state sodium batteries (SSBs) is one of the most concerned issues that critically affect the battery efficiency and cycling performance. Here, by designing a fluorescent Eu3+-doped Na3Zr2Si2PO12 solid electrolyte (SE) to facilitate three-dimensional (3D) optical imaging on a confocal laser scanning microscopy, a fluorescence tomography (FT) method is developed for observing the sodium dendrite growth during charge/discharge cycles of the SSBs in a 3D view. It is quantitatively revealed that small-size sodium islands appear after several cycles, and with the cycles increasing, large-size dendrites in tens of micrometers gradually form until a critical sodium dendrite volume arrives where a short circuit or severe performance deterioration occurs. Furthermore, by regulating the Eu3+ doping ratio, a record-high sodium plating/stripping cycling stability for more than 1 year (487.5 days) is achieved at 25°C. This work demonstrates an FT method observing sodium dendrite growth in SSBs and will promote the functional design of high-performance SEs.
固态钠电池（SSB）中的枝晶生长是最受关注的问题之一，它严重影响了电池的效率和循环性能。在此，通过设计一种掺杂荧光 Eu3+ 的 Na3Zr2Si2PO12 固体电解质（SE）来促进共聚焦激光扫描显微镜的三维（3D）光学成像，开发了一种荧光层析成像（FT）方法，以三维视图观察固态钠电池充放电循环过程中钠枝晶的生长。结果定量显示，几个周期后会出现小尺寸的钠岛，随着周期的增加，会逐渐形成数十微米的大尺寸树突，直到钠树突体积达到临界点，此时会发生短路或严重的性能下降。此外，通过调节 Eu3+ 的掺杂比例，在 25°C 下实现了创纪录的钠电镀/剥离循环稳定性，时间超过 1 年（487.5 天）。这项工作展示了一种在 SSB 中观察钠树枝状生长的 FT 方法，并将促进高性能 SE 的功能设计。
{"title":"Imaging dendrite growth in solid-state sodium batteries using fluorescence tomography technology","authors":"Shuaishuai Yang, Na Li, Enyue Zhao, Chengzhi Wang, Jingxin He, Xiong Xiao, Debao Fang, Qing Ni, Xile Han, Xiaobin Xue, Lai Chen, Ning Li, Jingbo Li, Tuan Guo, Yuefeng Su, Haibo Jin","doi":"10.1126/sciadv.adr0676","DOIUrl":"10.1126/sciadv.adr0676","url":null,"abstract":"<div >Dendrite growth in solid-state sodium batteries (SSBs) is one of the most concerned issues that critically affect the battery efficiency and cycling performance. Here, by designing a fluorescent Eu<sup>3+</sup>-doped Na<sub>3</sub>Zr<sub>2</sub>Si<sub>2</sub>PO<sub>12</sub> solid electrolyte (SE) to facilitate three-dimensional (3D) optical imaging on a confocal laser scanning microscopy, a fluorescence tomography (FT) method is developed for observing the sodium dendrite growth during charge/discharge cycles of the SSBs in a 3D view. It is quantitatively revealed that small-size sodium islands appear after several cycles, and with the cycles increasing, large-size dendrites in tens of micrometers gradually form until a critical sodium dendrite volume arrives where a short circuit or severe performance deterioration occurs. Furthermore, by regulating the Eu<sup>3+</sup> doping ratio, a record-high sodium plating/stripping cycling stability for more than 1 year (487.5 days) is achieved at 25°C. This work demonstrates an FT method observing sodium dendrite growth in SSBs and will promote the functional design of high-performance SEs.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578186/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takayoshi Shirasaki, Erik Lenarcic, Ichiro Misumi, Ling Xie, William G. Fusco, Bryan Yonish, Anshuman Das, Hyejeong Kim, Craig E. Cameron, Mélissa Léger-Abraham, Xian Chen, John M. Cullen, Jason K. Whitmire, You Li, Joseph A. Duncan, Nathaniel J. Moorman, Stanley M. Lemon
The overexpression and misfolding of viral proteins in the endoplasmic reticulum (ER) may cause cellular stress, thereby inducing a cytoprotective, proteostatic host response involving phosphorylation of eukaryotic translation initiation factor 2 subunit alpha (eIF2α). Here, we show that hepatitis A virus, a positive-strand RNA virus responsible for infectious hepatitis, adopts a stress-resistant, eIF2α-independent mechanism of translation to ensure the synthesis of viral proteins within the infected liver. Cap-independent translation directed by the hepatovirus internal ribosome entry site and productive hepatovirus infection of mice both require platelet-derived growth factor subunit A (PDGFA)–associated protein 1 (PDAP1), a small phosphoprotein of unknown function with eIF4E-binding activity. PDAP1 also interacts with eIF1A and is essential for translating stress-resistant host messenger RNAs that evade the proteostatic response to ER stress and that encode proteins promoting the survival of stressed cells.
{"title":"Hepatovirus translation requires PDGFA-associated protein 1, an eIF4E-binding protein regulating endoplasmic reticulum stress responses","authors":"Takayoshi Shirasaki, Erik Lenarcic, Ichiro Misumi, Ling Xie, William G. Fusco, Bryan Yonish, Anshuman Das, Hyejeong Kim, Craig E. Cameron, Mélissa Léger-Abraham, Xian Chen, John M. Cullen, Jason K. Whitmire, You Li, Joseph A. Duncan, Nathaniel J. Moorman, Stanley M. Lemon","doi":"10.1126/sciadv.adq6342","DOIUrl":"10.1126/sciadv.adq6342","url":null,"abstract":"<div >The overexpression and misfolding of viral proteins in the endoplasmic reticulum (ER) may cause cellular stress, thereby inducing a cytoprotective, proteostatic host response involving phosphorylation of eukaryotic translation initiation factor 2 subunit alpha (eIF2α). Here, we show that hepatitis A virus, a positive-strand RNA virus responsible for infectious hepatitis, adopts a stress-resistant, eIF2α-independent mechanism of translation to ensure the synthesis of viral proteins within the infected liver. Cap-independent translation directed by the hepatovirus internal ribosome entry site and productive hepatovirus infection of mice both require platelet-derived growth factor subunit A (PDGFA)–associated protein 1 (PDAP1), a small phosphoprotein of unknown function with eIF4E-binding activity. PDAP1 also interacts with eIF1A and is essential for translating stress-resistant host messenger RNAs that evade the proteostatic response to ER stress and that encode proteins promoting the survival of stressed cells.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578187/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Considering the characteristics and operating environment of remotely controlled miniature soft robots, achieving delicate adhesion control over various target surfaces is a substantial challenge. In particular, the ability to delicately grasp wrinkled and soft biological and nonbiological surfaces with low preload without causing damage is essential. The proposed adhesive robotic system, inspired by the secretions from a velvet worm, uses a structured magnetorheological material that exhibits precise adhesion control with stability and repeatability by the rapid stiffness change controlled by an external magnetic field. The proposed adhesion protocol involves controlling soft-state adhesion, maintaining a large contact area, and enhancing the elastic modulus, and the mechanical structure enhances the effectiveness of this protocol. Demonstrations of the remote adhesive robot include stable transportation in soft and wet organs, unscrewing a nut from a bolt, and supporting mouse tumor removal surgery. These results indicate the potential applicability of the soft adhesive robot in biomedical engineering, especially for targeting small-scale biological tissues and organisms.
{"title":"Stiffness-tunable velvet worm–inspired soft adhesive robot","authors":"Hyeongho Min, Daebeom Bae, Siyeon Jang, Sangmin Lee, Myungjin Park, Cem Balda Dayan, Jiwoong Choi, Keungyonh Bak, Yoosoo Yang, Sungwoo Chun, Metin Sitti","doi":"10.1126/sciadv.adp8260","DOIUrl":"10.1126/sciadv.adp8260","url":null,"abstract":"<div >Considering the characteristics and operating environment of remotely controlled miniature soft robots, achieving delicate adhesion control over various target surfaces is a substantial challenge. In particular, the ability to delicately grasp wrinkled and soft biological and nonbiological surfaces with low preload without causing damage is essential. The proposed adhesive robotic system, inspired by the secretions from a velvet worm, uses a structured magnetorheological material that exhibits precise adhesion control with stability and repeatability by the rapid stiffness change controlled by an external magnetic field. The proposed adhesion protocol involves controlling soft-state adhesion, maintaining a large contact area, and enhancing the elastic modulus, and the mechanical structure enhances the effectiveness of this protocol. Demonstrations of the remote adhesive robot include stable transportation in soft and wet organs, unscrewing a nut from a bolt, and supporting mouse tumor removal surgery. These results indicate the potential applicability of the soft adhesive robot in biomedical engineering, especially for targeting small-scale biological tissues and organisms.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578180/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142681518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Travis G. Novak, Austin E. Herzog, Matthew R. Buck, Ronnell J. Spears, Kyle Sendgikoski, Ryan H. DeBlock, Todd H. Brintlinger, Paul A. DeSario, Debra R. Rolison
Nickel-based catalysts are widely studied for water-gas shift (WGS), a key intermediate step in hydrogen production from carbon-based feedstocks. Their viability under practical conditions is limited at high temperatures when Ni aggregates and converts CO to methane, an undesirable side product. Because experimental and computational studies identify undercoordinated Ni step sites as most active toward CH4 formation, we eliminate Ni step sites by atomically dispersing Ni into networked, nanoparticulate CeO2 aerogels. The mesoporous catalyst with 2.5 atomic % Ni in CeO2 is highly active for WGS, converting near-equilibrium levels of CO at 350°C, while no CH4 is detected at the limit of detection (<2 parts per million). In contrast, supporting low weight percentages of Ni clusters or nanoparticles on CeO2 aerogels leads to methanation. The CH4 yield produced by the atomically dispersed Ni-substituted CeO2 aerogel is over an order of magnitude lower than previously reported Ni-based catalysts claiming methane suppression, marking an important advance in the development of WGS catalysts.
{"title":"Atomically dispersed nickel in CeO2 aerogel catalysts completely suppresses methanation in the water-gas shift reaction","authors":"Travis G. Novak, Austin E. Herzog, Matthew R. Buck, Ronnell J. Spears, Kyle Sendgikoski, Ryan H. DeBlock, Todd H. Brintlinger, Paul A. DeSario, Debra R. Rolison","doi":"10.1126/sciadv.adr9120","DOIUrl":"10.1126/sciadv.adr9120","url":null,"abstract":"<div >Nickel-based catalysts are widely studied for water-gas shift (WGS), a key intermediate step in hydrogen production from carbon-based feedstocks. Their viability under practical conditions is limited at high temperatures when Ni aggregates and converts CO to methane, an undesirable side product. Because experimental and computational studies identify undercoordinated Ni step sites as most active toward CH<sub>4</sub> formation, we eliminate Ni step sites by atomically dispersing Ni into networked, nanoparticulate CeO<sub>2</sub> aerogels. The mesoporous catalyst with 2.5 atomic % Ni in CeO<sub>2</sub> is highly active for WGS, converting near-equilibrium levels of CO at 350°C, while no CH<sub>4</sub> is detected at the limit of detection (<2 parts per million). In contrast, supporting low weight percentages of Ni clusters or nanoparticles on CeO<sub>2</sub> aerogels leads to methanation. The CH<sub>4</sub> yield produced by the atomically dispersed Ni-substituted CeO<sub>2</sub> aerogel is over an order of magnitude lower than previously reported Ni-based catalysts claiming methane suppression, marking an important advance in the development of WGS catalysts.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578172/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prasanna Das, Sourav Rudra, Dheemahi Rao, Souvik Banerjee, Ashalatha Indiradevi Kamalasanan Pillai, Magnus Garbrecht, Alexandra Boltasseva, Igor V. Bondarev, Vladimir M. Shalaev, Bivas Saha
Plasmon resonance represents the collective oscillation of free electron gas density and enables enhanced light-matter interactions in nanoscale dimensions. Traditionally, the classical Drude model describes plasmonic excitation, wherein plasma frequency exhibits no spatial dispersion. Here, we show conclusive experimental evidence of the breakdown of plasmon resonance and a consequent metal-insulator transition in an ultrathin refractory plasmonic material, hafnium nitride (HfN). Epitaxial HfN thick films exhibit a low-loss and high-quality Drude-like plasmon resonance in the visible spectral range. However, as the film thickness is reduced to nanoscale dimensions, Coulomb interaction among electrons increases because of electron confinement, leading to the spatial dispersion of plasma frequency. With a further decrease in thickness, electrons lose their ability to shield the incident electric field, turning the medium into a dielectric. The observed metal-insulator transition might carry some signatures of Wigner crystallization and indicates that such transdimensional, between 2D and 3D, films can serve as a promising playground to study strongly correlated electron systems.
{"title":"Electron confinement–induced plasmonic breakdown in metals","authors":"Prasanna Das, Sourav Rudra, Dheemahi Rao, Souvik Banerjee, Ashalatha Indiradevi Kamalasanan Pillai, Magnus Garbrecht, Alexandra Boltasseva, Igor V. Bondarev, Vladimir M. Shalaev, Bivas Saha","doi":"10.1126/sciadv.adr2596","DOIUrl":"10.1126/sciadv.adr2596","url":null,"abstract":"<div >Plasmon resonance represents the collective oscillation of free electron gas density and enables enhanced light-matter interactions in nanoscale dimensions. Traditionally, the classical Drude model describes plasmonic excitation, wherein plasma frequency exhibits no spatial dispersion. Here, we show conclusive experimental evidence of the breakdown of plasmon resonance and a consequent metal-insulator transition in an ultrathin refractory plasmonic material, hafnium nitride (HfN). Epitaxial HfN thick films exhibit a low-loss and high-quality Drude-like plasmon resonance in the visible spectral range. However, as the film thickness is reduced to nanoscale dimensions, Coulomb interaction among electrons increases because of electron confinement, leading to the spatial dispersion of plasma frequency. With a further decrease in thickness, electrons lose their ability to shield the incident electric field, turning the medium into a dielectric. The observed metal-insulator transition might carry some signatures of Wigner crystallization and indicates that such transdimensional, between 2D and 3D, films can serve as a promising playground to study strongly correlated electron systems.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.science.org/doi/reader/10.1126/sciadv.adr2596","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seungjun Lee, D. J. P. de Sousa, Bharat Jalan, Tony Low
Through first-principles calculations based on density functional theory, we investigate the crystal and electronic structures of twisted bilayer BaTiO3. Our findings reveal that large stacking fault energy leads to a chiral in-plane vortex pattern that was recently observed in experiments. We also found nonzero out-of-plane local dipole moments, indicating that the strong interlayer interaction might offer a promising strategy to stabilize ferroelectric order in the two-dimensional limit. The vortex pattern in the twisted BaTiO3 bilayer supports localized electronic states with quasi-flat bands, associated with the interlayer hybridization of oxygen pz orbitals. We found that the associated bandwidth reaches a minimum at ∼19∘ twisting, configuring the largest magic angle in moiré systems reported so far. Further, the moiré vortex pattern bears a notable resemblance to two interpenetrating Lieb lattices and the corresponding tight-binding model provides a comprehensive description of the evolution the moiré bands with twist angle and reveals the topological nature.
{"title":"Moiré polar vortex, flat bands, and Lieb lattice in twisted bilayer BaTiO3","authors":"Seungjun Lee, D. J. P. de Sousa, Bharat Jalan, Tony Low","doi":"10.1126/sciadv.adq0293","DOIUrl":"10.1126/sciadv.adq0293","url":null,"abstract":"<div >Through first-principles calculations based on density functional theory, we investigate the crystal and electronic structures of twisted bilayer BaTiO<sub>3</sub>. Our findings reveal that large stacking fault energy leads to a chiral in-plane vortex pattern that was recently observed in experiments. We also found nonzero out-of-plane local dipole moments, indicating that the strong interlayer interaction might offer a promising strategy to stabilize ferroelectric order in the two-dimensional limit. The vortex pattern in the twisted BaTiO<sub>3</sub> bilayer supports localized electronic states with quasi-flat bands, associated with the interlayer hybridization of oxygen <i>p<sub>z</sub></i> orbitals. We found that the associated bandwidth reaches a minimum at ∼19<sup>∘</sup> twisting, configuring the largest magic angle in moiré systems reported so far. Further, the moiré vortex pattern bears a notable resemblance to two interpenetrating Lieb lattices and the corresponding tight-binding model provides a comprehensive description of the evolution the moiré bands with twist angle and reveals the topological nature.</div>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":""},"PeriodicalIF":11.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578177/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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