ACS NanoPub Date : 2025-05-29DOI: 10.1021/acsnano.5c04839
Ali A. Alizadehmojarad, Sergei M. Bachilo, R. Bruce Weisman
{"title":"Guanine Functionalization of Single-Wall Carbon Nanotubes: A Quantum Chemical Study","authors":"Ali A. Alizadehmojarad, Sergei M. Bachilo, R. Bruce Weisman","doi":"10.1021/acsnano.5c04839","DOIUrl":"https://doi.org/10.1021/acsnano.5c04839","url":null,"abstract":"The guanine functionalization reaction uses singlet oxygen to covalently link single-wall carbon nanotubes to guanine bases in ssDNA coatings. This creates shallow but densely spaced exciton traps that modulate nanotube band gaps with energetic and spatial control, giving red-shifted electronic transitions. To better understand guanine functionalization, we used quantum chemical computations to compare the stabilities of several candidate addends in multiple orientations on the nanotube surface. Structures of three possible isomers of guanine peroxide (GPO), the reactive intermediate formed through reaction of 9-methyl guanine with singlet O<sub>2</sub>, were optimized using the semiempirical PM3 method. To examine effects of nanotube diameter on adduct stability, we then computed the enthalpy changes for bonding of each GPO isomer to a 6 nm segment of (5,4), (6,5), (7,6), and (8,7) single-wall carbon nanotubes (SWCNTs). Six orientations of the addend on the SWCNT surface were considered for each (<i>n</i>,<i>m</i>) species, giving a total of 72 adduct structures. The results showed that for all four SWCNTs, the most energetically stable adduct is the 4,5-GPO isomer bonded in the ortho L<sub>–30</sub> orientation. This adduct can be considered to be a derivative of 1,4-dioxane. Subsequent <i>ab initio</i> DFT and TDDFT computations comparing bonding orientations of one guanine addend on a 12 nm long SWCNT segment found that ortho L<sub>–30</sub> gives a slightly reduced HOMO–LUMO gap, a moderately localized exciton structure, and a slightly red-shifted E<sub>11</sub> optical transition as compared to the pristine SWCNT, in agreement with experiment. We conclude that guanine functionalization of near-armchair SWCNTs leads mainly to 4,5-GPO addends bonded in the ortho L<sub>–30</sub> orientation.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"26 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165552","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":"Quasi-Ballistic Heat Conduction of Long-Range Surface Phonon Polaritons Coupled to Thermal Reservoirs","authors":"Sichao Li, Rosmin Elsa Mohan, Jingxuan Wang, Hong-Son Chu, Sunmi Shin","doi":"10.1021/acsnano.5c04594","DOIUrl":"https://doi.org/10.1021/acsnano.5c04594","url":null,"abstract":"Rigorous thermal control at the nanoscale has become essential with the miniaturization of electronic devices. However, heat transfer in such structures is hindered by increased boundary scatterings and reduced thermal conductivity. Surface phonon polaritons (SPhPs), arising from the coupling of optical phonons and photons in the mid-IR regime, present a promising solution as long-range heat carriers capable of circumventing the limitations faced by traditional heat carriers such as acoustic phonons in nanoscales. However, the detection and utilization of SPhP-mediated thermal conduction have proven to be challenging. Here, we introduce an innovative approach that employs a grating-integrated thermometry platform, specifically designed to enhance the transmission of SPhP modes with long decay lengths and detectability of SPhPs over short, ballistic distances. We demonstrate quasi-ballistic, length-independent thermal conduction mediated by long-range SPhPs in one-dimensional SiO<sub>2</sub> heat channels, achieving a SPhP thermal conductivity of 1.5 W/m K, which has been over 90% of the intrinsic thermal conductivity.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"9 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177236","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}
ACS NanoPub Date : 2025-05-29DOI: 10.1021/acsnano.5c04786
Robert M. Jacobberger, Zichun Miao, Ka-Man Yu, Yin Hei Lam, Zizhong Li, Yangchen He, Jia Wang, Katherine A. Su, Yashwrdhan Pathaare, Vivek Saraswat, Daniel A. Rhodes, Max G. Lagally, Michael S. Altman, Michael S. Arnold
{"title":"Overcoming Secondary Nucleation of Misoriented Domains during Wafer-Scale Epitaxy of Single-Crystal Graphene on Ge(110)","authors":"Robert M. Jacobberger, Zichun Miao, Ka-Man Yu, Yin Hei Lam, Zizhong Li, Yangchen He, Jia Wang, Katherine A. Su, Yashwrdhan Pathaare, Vivek Saraswat, Daniel A. Rhodes, Max G. Lagally, Michael S. Altman, Michael S. Arnold","doi":"10.1021/acsnano.5c04786","DOIUrl":"https://doi.org/10.1021/acsnano.5c04786","url":null,"abstract":"The wafer-scale synthesis of single-crystal graphene on technologically important substrates is a major challenge inhibiting the development of next-generation devices that harness the exceptional electronic, thermal, and mechanical properties of single-crystal graphene. Here, the factors controlling the domain orientation of graphene grown epitaxially on Ge(110) are elucidated, and this insight is utilized to produce graphene with minimal polycrystallinity. In the early stages of growth, most graphene islands have unidirectionally aligned lattices. However, we discover a secondary nucleation phenomenon in which misoriented graphene domains nucleate near/from the island edges, introducing defective grain boundaries and significantly increasing polycrystallinity throughout growth. We find that secondary nucleation occurs when islands grow over Ge steps, which form because of an interplay between the island growth and Ge surface topography evolution. Strategies for suppressing secondary nucleation are developed, enabling the synthesis of graphene in which the predominant crystal orientation has high coverage >99% and low rotational spread <0.6°. This work overcomes the irreproducibility of graphene epitaxy on Ge(110) reported in the literature, providing a route toward the large-area synthesis of single-crystal graphene on technologically useful semiconductors.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"14 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165632","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}
ACS NanoPub Date : 2025-05-29DOI: 10.1021/acsnano.4c15257
Offek Tziperman, Gefen Baranes, Alexey Gorlach, Ron Ruimy, Chen Mechel, Michael Faran, Nir Gutman, Andrea Pizzi, Ido Kaminer
{"title":"Nonlinear Quantum Light Generation in Collective Spontaneous Emission","authors":"Offek Tziperman, Gefen Baranes, Alexey Gorlach, Ron Ruimy, Chen Mechel, Michael Faran, Nir Gutman, Andrea Pizzi, Ido Kaminer","doi":"10.1021/acsnano.4c15257","DOIUrl":"https://doi.org/10.1021/acsnano.4c15257","url":null,"abstract":"Collective spontaneous emission occurs when multiple quantum emitters decay into common radiation modes, resulting in enhanced or suppressed emission. Here, we find that the quantum state of light collectively emitted from emitters exhibiting quantum correlations. We unveil under what conditions the quantum correlations are not lost during the emission but are instead transferred to the output light. Under these conditions, the inherent nonlinearity of the emitters can be tailored to create desired photonic states in the form of traveling single-mode pulses, such as Gottesman–Kitaev–Preskill and Schrödinger-cat states, that are useful for error correction in quantum computation. To facilitate such predictions, our work reveals the multimode nature of collective spontaneous emission, capturing the role of the emitters’ positions, losses, interactions, and beyond-Markov dynamics on the emitted quantum state of light. We present manifestations of these effects in different physical systems, with examples of cavity QED, waveguide QED, and atomic arrays with up to a few dozen emitters. Our findings suggest paths for creating and manipulating multiphoton quantum light for bosonic codes in continuous-variable-based quantum computation, communications, and sensing.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"41 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177226","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":"Using Machine Learning to Fast-Track Peptide Nanomaterial Discovery","authors":"Ena Dražić, Darijan Jelušić, Patrizia Janković Bevandić, Goran Mauša, Daniela Kalafatovic","doi":"10.1021/acsnano.5c00670","DOIUrl":"https://doi.org/10.1021/acsnano.5c00670","url":null,"abstract":"Peptides can serve as building blocks for supramolecular materials because of their unique ability to self-assemble, offering potential applications in drug delivery, tissue engineering, and nanotechnology. In this review, we describe peptide self-assembly as a sequence- and context-dependent process and its resulting complexity due to the heterogeneity of the sequences and experimental conditions, which makes cross-laboratory reproducibility a serious challenge and standardized reporting a necessity. Given the large number of possible peptide permutations, machine learning (ML) is suitable for navigating the peptide search space with the aim of reducing trial-and-error experimentation and speeding up the discovery of self-assembling peptides. However, we point out that ML is not a point-and-shoot tool that can be applied directly to any problem and requires careful consideration, domain knowledge, and proper data preparation to achieve meaningful results. In addition, we discuss the lack of negative data reported to be the main limiting factor in the effective application of ML. Considering the transformative potential of artificial intelligence, we conclude that grasping the power of large language models and generative approaches, coupled with explainability techniques, will expedite peptide nanomaterials discovery.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"11 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177227","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":"Manipulating Synergetic Effect of Atomic-Level Chemical and Structural Fluctuations on Magnetism in High-Entropy Oxides","authors":"Ning Guo, Hanbin Gao, Qing-Qiao Fu, Yue Gong, Dongwei Wang, Qiang Zheng","doi":"10.1021/acsnano.5c03674","DOIUrl":"https://doi.org/10.1021/acsnano.5c03674","url":null,"abstract":"High-entropy oxides, which incorporate five or more distinct cations into a single crystallographic site, are attracting significant attention, owing to their often unexpected physical and chemical properties. However, understanding and manipulation of local chemical compositions and structures and their dominance on material performance remain a significant challenge. Here, we investigate a prototype antiferromagnetic high-entropy oxide (Mg<sub>0.2</sub>Co<sub>0.2</sub>Ni<sub>0.2</sub>Cu<sub>0.2</sub>Zn<sub>0.2</sub>)O with rocksalt-type structure, and directly visualize local fluctuating lattice distortions and short-range ordering using advanced scanning transmission electron microscopy imaging. Degrees of chemical homogeneity and lattice distortions can be synergistically manipulated through thermal treatment temperatures, leading to correlative changes in the antiferromagnetic interaction and magnetic properties. We propose that local chemical and structural fluctuations synergistically affect magnetic interactions, with higher-temperature sintering reducing fluctuations and enhancing magnetic coupling. This work provides insights into the tunability of local fluctuating compositions and structures in high-entropy oxides, contributing to the desired functionalities in more high-entropy materials.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"62 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177235","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}
ACS NanoPub Date : 2025-05-29DOI: 10.1021/acsnano.5c03331
Andrey V. Matetskiy, Alessandro Barla, Paolo Moras, Carlo Carbone, Valeria Milotti, Carlo Alberto Brondin, Zipporah Rini Benher, Mariia Holub, Philippe Ohresser, Edwige Otero, Fadi Choueikani, Igor A. Shvets, Alexey N. Mihalyuk, Sergey V. Eremeev, Polina M. Sheverdyaeva
{"title":"Germanene-Based Two-Dimensional Magnet with Tunable Properties","authors":"Andrey V. Matetskiy, Alessandro Barla, Paolo Moras, Carlo Carbone, Valeria Milotti, Carlo Alberto Brondin, Zipporah Rini Benher, Mariia Holub, Philippe Ohresser, Edwige Otero, Fadi Choueikani, Igor A. Shvets, Alexey N. Mihalyuk, Sergey V. Eremeev, Polina M. Sheverdyaeva","doi":"10.1021/acsnano.5c03331","DOIUrl":"https://doi.org/10.1021/acsnano.5c03331","url":null,"abstract":"Magnetic order engineering in two-dimensional Dirac systems is of great interest for theoretical and technological exploration. Up to now, the experimental advances in this field mostly concerned graphene monolayers. Here, we report a comprehensive study of a monolayer-thick germanene-like sheet in contact with gadolinium atoms. Direct observations supported by first-principles calculations reveal the fingerprints of the Dirac fermions in the electronic structure and noncollinear antiferromagnetism. The hybridization of the germanene layer with Gd atoms leads to a large and tunable gap in the Dirac states that carry a nonzero spin-Berry curvature. We discovered that cesium-induced controlled electron doping can switch the system into a ferromagnetic state and then back to the antiferromagnetism at saturated cesium monolayer limit. We explain these reversible magnetic transitions by the oscillatory behavior of the Ruderman–Kittel–Kasuya–Yosida interaction and suggest that this system could find application in magnetoelectronics and spintronics.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"43 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177232","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}
ACS NanoPub Date : 2025-05-29DOI: 10.1021/acsnano.5c02629
Kyu-Hyun Han, Hyun-Yong Yu
{"title":"Progress and Challenges of 2D van der Waals Multi-Valued Logic Technology","authors":"Kyu-Hyun Han, Hyun-Yong Yu","doi":"10.1021/acsnano.5c02629","DOIUrl":"https://doi.org/10.1021/acsnano.5c02629","url":null,"abstract":"Since the inception of the semiconductor industry, binary logic computing systems have been deeply embedded in our community. However, with the advent of the AI era, the information processing speed of Si CMOS-based binary logic systems has reached its limits with the current technology. For overcoming this, multi-valued logic (MVL) has garnered attention as a high-density computing system that can rapidly process large amounts of information due to there being fewer unit devices and it having low power consumption compared to binary logic. Furthermore, as we approach the 1 nm node era by Moore’s Law, 2D van der Waals (vdW) materials are highlighted for their potential to overcome the limitations of Si materials. Therefore, 2D vdW MVL technology represents the next-generation high-density computing system that is essential for device miniaturization. Here, this review introduces the technological advancements of 2D vdW MVL. First, the history of 2D vdW MVL and the various operation principles are explained for implementing MVL technology. Next, various techniques for implementing vdW MVL were categorized, and the development of these techniques was discussed over time. Finally, this review presents the conclusion by examining the current technological status of vdW MVL and its future prospects.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"26 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144177234","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":"Capillary Force-Driven Capture of Magnetic Nanoparticles in Calcium Phosphate Hollow-Tube Whisker Scaffolds for Osteonecrosis of the Femoral Head","authors":"Yi Zhou, Cong Feng, Xiaolong Yang, Jiang Yu, Xiangfeng Li, Weili Fu, Xiangdong Zhu, Jian Li, Xingdong Zhang","doi":"10.1021/acsnano.5c02874","DOIUrl":"https://doi.org/10.1021/acsnano.5c02874","url":null,"abstract":"Excessive glucocorticoid use disrupts osteogenesis and angiogenesis in the femoral head, leading to steroid-induced osteonecrosis of the femoral head (SONFH), which is a significant clinical challenge. This study introduces a magnetically responsive biphasic calcium phosphate (HBCP/Fe<sub>3</sub>O<sub>4</sub>) scaffold featuring a nanoparticle-embedded hollow-tube whisker structure. The scaffold was fabricated through an <i>in situ</i> growth process to generate hollow-tube whiskers, followed by a capillary trapping technique that allowed the hollow-tube whiskers to capture Fe<sub>3</sub>O<sub>4</sub> nanoparticles (NPs), achieving uniform and efficient encapsulation. HBCP/Fe<sub>3</sub>O<sub>4</sub> exhibited excellent magnetic responsiveness and significant biological effects under static magnetic field (SMF) stimulation. <i>In vitro</i>, HBCP/Fe<sub>3</sub>O<sub>4</sub> under SMF promoted osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in a glucocorticoid microenvironment, enhanced angiogenesis in human umbilical vein endothelial cells (HUVECs), and induced M2 polarization of RAW 264.7 murine macrophage cells (RAW 264.7). Furthermore, HBCP/Fe<sub>3</sub>O<sub>4</sub> under SMF stimulation orchestrated paracrine signaling from endothelial and immune cells, thereby enhancing the osteogenic differentiation of BMSCs. Mechanistically, the osteogenic differentiation of BMSCs was driven by magnetic stimulation-induced Piezo1-mediated Ca<sup>2+</sup> influx, which activated BMP-2/Smad signaling and upregulated key osteogenic markers. <i>In vivo</i>, the implantation of HBCP/Fe<sub>3</sub>O<sub>4</sub> scaffolds under SMF stimulation in a rabbit SONFH model promoted coordinated therapeutic effects, including robust bone regeneration, <i>in situ</i> revascularization, immunomodulation, and preservation of femoral head cartilage. Together, these findings support the clinical relevance of this magnetically responsive scaffold as a multifunctional strategy for delaying structural deterioration and facilitating comprehensive repair in SONFH.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"1 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165555","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":"Silicon Heterojunction Solar Cells with Nanocrystalline Silicon Oxide Emitter for Achieving High Fill Factor","authors":"Qi Wang, Cui Yuhan, Fengzhen Liu, Dongsheng Liu, Zongheng Sun, Gangqiang Dong, Junming Huang, Yuqin Zhou, Yurong Zhou","doi":"10.1021/acsnano.5c03395","DOIUrl":"https://doi.org/10.1021/acsnano.5c03395","url":null,"abstract":"Emitter and transparent conductive oxide (TCO) films are the critical functional layers of extremely promising silicon heterojunction (SHJ) solar cells. Here, p-type nanocrystalline silicon oxide (nc-SiO<sub><i>x</i></sub>:H(p<sup>+</sup>)) are employed as the emitter, replacing the widely used nanocrystalline silicon. The nc-SiO<sub><i>x</i></sub>:H shows a mixed-phase structural characteristic of nanocrystalline silicon grains and amorphous silicon oxide, in which the former spans the whole emitter, facilitating the carrier collection. A variety of TCO films, including Ce, Sn, or Hf doped and undoped indium oxides, are optimized for the nc-SiO<sub><i>x</i></sub>:H(p<sup>+</sup>) emitter. Film quality, work function, and bandgap states of the TCO films affect the contact resistivity of TCO/nc-SiO<sub><i>x</i></sub>:H(p<sup>+</sup>) and the solar cell performance. Using Ce doped indium oxide (ICO) with high mobility and certain bandgap states as the TCO layers, an efficiency of 26.29% and a high fill factor (FF) of 86.21% are achieved on the champion bifacial SHJ solar cells.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"68 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165654","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}