Materials and Structures最新文献

{"title":"Design, fabrication, and assembly of a non-linear reinforced 3D-printed concrete footbridge: a case study","authors":"Hailong Wang,&nbsp;Simin Chen,&nbsp;Haoran Liu,&nbsp;Xiqiang Lin,&nbsp;Dong Chen,&nbsp;Xiaoyan Sun","doi":"10.1617/s11527-026-03274-3","DOIUrl":"10.1617/s11527-026-03274-3","url":null,"abstract":"<div><p>As 3D concrete printing (3DCP) technology transitions from material development to practical engineering applications, achieving large-span nonlinear geometries, continuous reinforcement integration, and monolithic post-poured structures has emerged as a key research frontier. This study systematically presents a “design-analysis-fabrication-assembly” workflow through a case study of a 3D-printed concrete landscape bridge in Ningbo, measuring 15,975 mm in length and 3100 mm in width. The bridge adopts a nonlinear self-supporting shallow arch configuration. Its structural safety and serviceability under complex loading conditions were evaluated using Rhino, Midas, and nonlinear finite element analysis with Abaqus. Modal analysis yielded a fundamental frequency of 12.186 Hz. A simplified seismic check using a single 0.1 g artificial record indicated a stable global response, with component stresses within the material design limits and damage concentrated mainly near the support transition regions. Regarding fabrication, a large-scale gantry-type system was employed for the vertical-plane printing of six precast units. To address the load-transfer discontinuity inherent in segmented printing, a “segmental fabrication and systematic integration” logic was implemented. By lap-welding longitudinal reinforcement within post-poured belts and incorporating continuous steel meshes with high-strength non-shrink grout, continuous load-transfer paths across the segment joints were established. Overall, this case study documents a project-specific workflow for the design, numerical assessment, fabrication, and assembly of a full-scale nonlinear 3DCP bridge.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fly ash-based nano silica through reactive CO2 uptake","authors":"Mude Sivaramnaik,&nbsp;K. Chiranjeevi Reddy,&nbsp;Kolluru V. L. Subramaniam","doi":"10.1617/s11527-026-03260-9","DOIUrl":"10.1617/s11527-026-03260-9","url":null,"abstract":"<div><p>Fly Ash-Based Nano-Silica (FABANS) for use in cementitious binders is produced by alkaline leaching of fly ash. An activating solution with reactive silica and reduced free alkali content is produced by carbonating the alkaline FABANS solution. The reactive carbon uptake by the FABANS stabilizes free alkalis as carbonates and produces an activating solution containing highly reactive colloidal silica. Activated nano-silica with carbonated alkalis significantly enhances the early reactivity of hydrating cementitious systems, as evidenced by kinetic measurements. Up to a 51.6% enhancement in early strength gain is observed on the first day with a 10% replacement of Ordinary Portland cement with carbonated FABANS. The enhanced reactivity and strength gain in the activated system are associated with silica enrichment of the early CSH gel. There is enhanced calcite precipitation in the activated cementitious binder. Additionally, the formation of new carbonate phases in the hydrated binder helps reduce porosity. Nano-silica produced by carbonating the alkaline FABANS enhanced early strength gain while offsetting the loss of later-age strength in the presence of sodium-based compounds.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From fabrication process to structural performance: exploring test procedures and design models for digitally fabricated concrete","authors":"Sven Engel,&nbsp;Eduarda Dilkin,&nbsp;Martin Classen","doi":"10.1617/s11527-026-03258-3","DOIUrl":"10.1617/s11527-026-03258-3","url":null,"abstract":"<div><p>Digital fabrication enables new possibilities for structurally optimized and resource-efficient reinforced concrete construction. In particular, extrusion-based 3D concrete printing (3DCP) allows the production of load-adapted geometries without conventional formwork. However, the structural application of reinforced 3D-printed concrete remains limited due to unresolved challenges regarding reinforcement integration and the applicability of existing structural design approaches. This paper presents a multimodal fabrication strategy combining 3DCP, casting, and integrated carbon-fiber reinforced polymer (CFRP) reinforcement for the digital production of reinforced concrete members. To investigate the resulting structural behavior, a comprehensive experimental program was conducted covering material characterization, bond behavior, bending, shear, and punching shear. Particular focus was placed on the interaction between fabrication-induced characteristics and structural load-transfer mechanisms. The experimental investigations demonstrate that optimized nozzle orientation significantly improves the bond behavior between CFRP reinforcement and 3D-printed concrete. Compared to cast reference specimens, the bond capacity of the printed specimens was reduced by 23–41%, depending on the nozzle orientation. Structural tests on beams revealed that conventional sectional analysis approaches can successfully predict flexural behavior. In contrast, the experimentally observed shear resistance of the beam without shear reinforcement was approximately 48% lower than the guideline-based prediction, highlighting the necessity of considering fabrication-induced anisotropy and interlayer delamination. The observed discrepancies are attributed to the anisotropic material behavior and reduced interlayer bond resulting from the layer-wise fabrication process. To address these effects, an existing physics-based shear model was critically evaluated and extended for application to digitally fabricated concrete members. In particular, the Shear Crack Propagation Theory (SCPT) was extended by incorporating interface delamination mechanisms specific to 3D-printed concrete. In combination with experimentally derived reinforcement contributions, the proposed hybrid modeling approach reproduced the experimentally observed shear capacities with deviations below 9%. The proposed framework demonstrates that reliable structural design of reinforced 3D-printed concrete cannot rely solely on conventional empirical approaches but requires mechanics-based models explicitly accounting for fabrication-induced characteristics. The presented methodology provides a transferable framework linking digital fabrication processes with structural performance and establishes a basis for the development of future design provisions for reinforced 3D-printed concrete.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03258-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compositional variability of natural hydraulic limes (NHL) in Europe. Part 1: comparative analysis of raw materials and manufacturing processes across eight European producers","authors":"C. Parra-Fernández,&nbsp;A. Arizzi","doi":"10.1617/s11527-026-03268-1","DOIUrl":"10.1617/s11527-026-03268-1","url":null,"abstract":"<div><p>This research aims to highlight the different manufacturing factors that influence the compositional variability of natural hydraulic limes (NHL). For this purpose, the main production stages of eight commercial NHL factories have been studied, in order to understand how the raw materials selection, calcination and slaking influence the final properties of NHLs available on the European market today. Beyond geological variability in carbonate-clay raw materials, the results obtained in this study can be interpreted as the direct outcome of manufacturer-specific production routes, where extraction, kiln operation, fuel selection, and slaking/grinding strategies act as coupled variables controlling the final chemical and mineralogical composition and performance of natural hydraulic limes. This research demonstrates that accounting for manufacturing-related aspects is essential for achieving more accurate standardisation of NHL.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03268-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unlocking unexplained characteristics of MgO: a review by RILEM TC 311-MBC","authors":"Hoang Nguyen,&nbsp;Charlotte Dewitte,&nbsp;Fei Jin,&nbsp;Yiming Peng,&nbsp;Sanket Rawat,&nbsp;Tingting Zhang,&nbsp;Nirrupama K. Ilango,&nbsp;Dan Meng,&nbsp;Tangei Mi,&nbsp;Matthias Müller,&nbsp;Dung Nguyen,&nbsp;Daman Panesar,&nbsp;Navid Ranjbar,&nbsp;Shaoqin Ruan,&nbsp;Vineet Shah,&nbsp;Runxiao Zhang,&nbsp;Zeyu Zhou,&nbsp;Cise Unluer","doi":"10.1617/s11527-026-03231-0","DOIUrl":"10.1617/s11527-026-03231-0","url":null,"abstract":"<div><p>MgO-based cements hold promises as alternatives to Portland cement with radically reduced carbon footprint. MgO plays a centric role in the reaction and formation of these cements. This review is a part of RILEM TC-311 MBC where we discussed the current understanding about the behaviors of MgO in magnesium carbonate (MC) and magnesium silicate (MS) cements. In addition, we reviewed practices in characterizing MgO and available processes to produce MgO in industrial scale. There are several unexpected and unexplained phenomena which likely link to the characteristics of MgO in both MC and MS cements. This distinguishes the MgO-cements from Portland cement and eventually several practices and know-how commonly used in cement research are not applicable and need further insights. Furthermore, the selection of MgO type and characteristics seems crucial to achieve the desired properties for both MC and MS cements. We also point out research needed in this topic to pave the way for MgO-based cements to progress toward their promises.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03231-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Connecting prefabricated concrete to CLT: an experimental comparison of adhesive vs. mechanical connections for dry timber-concrete composites (TCC) joints","authors":"F. P. Galarza,&nbsp;J. Basaure-Fuentes,&nbsp;P. Guindos,&nbsp;G. Araya-Letelier","doi":"10.1617/s11527-026-03275-2","DOIUrl":"10.1617/s11527-026-03275-2","url":null,"abstract":"<div><p>Dry timber-concrete composite (TCC) systems are a promising construction solution for facilitating prefabrication of timber-concrete elements in buildings, eliminating the need for on-site wet work. This study evaluates two groups of dry TCC joints: adhesive-bonded TCC (ATCC) and self-tapping screw TCC (STS-TCC), in order to assess structural performance and constructability. Both joint types were tested under monotonic loading to obtain their mechanical responses, including modes of failure, ductility, ultimate load capacity, slip modulus, and joint stiffness. The study also assessed three commercial epoxy adhesives, three fabrication techniques, and the size effect (change in bond length) to identify the best commercial epoxy adhesive for ATCC joints. The main results demonstrate the need for good manufacturing practices when assembling dry ATCC to achieve superior joint efficiency and avoid stress concentrations. Although these joints are prone to brittle failures at ultimate loading, they offer higher stiffness and superior shear strength. In contrast, STS-TCC joints exhibit ductile post-peak behavior due to the primary failure mode (screw withdrawal) observed. ATCC joints are slip-free and perform well under monotonic loading when manufactured correctly—adhesive agent penetration into the substrates must be guaranteed, ensuring substrate failure rather than adhesion failure. Dry STS-TCC joints are less sensitive to the construction process as long as the fasteners are correctly installed. In this case, a ductile response is expected, with shear capacity determined by the number of screws employed and their spacing (discrete distribution). Despite these shortcomings, TCC systems with mechanical fasteners (screws) are widely accepted due to their superior reliability.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unlocking multifunctional behavior of cellulose nanomaterials in cementitious systems through controlled dispersion: rheology, hydration kinetics, and mechanical performance","authors":"Belkis Selma Aouichat,&nbsp;Masoud Hosseinpoor,&nbsp;Ammar Yahia,&nbsp;Mario Dupuis","doi":"10.1617/s11527-026-03267-2","DOIUrl":"10.1617/s11527-026-03267-2","url":null,"abstract":"<div><p>This study investigated the multifunctional behavior of optimally dispersed cellulose nanomaterials (CNMs), namely cellulose nanocrystals (CNC) and cellulose nanofibers (CNF), in cement pastes using tailored superplasticizer (SP) chemistry and optimized mixing sequences. A wide dosage range (0.03–0.20 wt.%) was examined to evaluate the influence of CNMs on rheology, structuration kinetics, hydration behavior, and mechanical performance. Results revealed that dispersion state governs CNM functionality in cementitious systems. Their performance depends not only on their intrinsic morphology but also on their dispersion state, which can be effectively controlled through appropriate superplasticizer chemistry and mixing sequence. Well-dispersed CNC exhibited dosage-dependent dual behavior: at low contents (≤ 0.08 wt.%), CNC enhanced packing density and lubrication, reducing plastic viscosity while preserving structural integrity; at higher dosages, CNC acted as viscosity-modifying agents, increasing rigidity and accelerating hydration through nucleation effects. In contrast, CNF consistently increased flow resistance and structural build-up due to the formation of entangled fibrillar networks. At higher dosages, CNF displayed an internal curing agent effect, releasing absorbed water and producing substantial improvements in mechanical performance, including increases of up to 15.7% in compressive and 60.1% in flexural strengths. Overall, these findings demonstrate that dispersion-controlled CNM functionality enables the design of multifunctional cementitious systems with tailored rheology, hydration kinetics, and mechanical performance. The proposed dispersion strategy relies mainly on controlled mixing procedures and compatible superplasticizer chemistry, providing a scalable pathway for integrating CNMs into advanced construction technologies, such as 3D concrete printing.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An alternative formulation of concrete fatigue S–N curves considering dynamic strength","authors":"Álvaro Mena-Alonso,&nbsp;Jesús Mínguez,&nbsp;Dorys C. González,&nbsp;Miguel A. Vicente","doi":"10.1617/s11527-026-03281-4","DOIUrl":"10.1617/s11527-026-03281-4","url":null,"abstract":"<div><p>This paper addresses a limitation in the conventional <i>S</i>–<i>N</i> curve approach for concrete fatigue, which assumes that failure occurs in the first cycle when the maximum cyclic stress equals the static strength (<i>S</i>_max= 1). Since the compressive strength of concrete is sensitive to the loading rate, an alternative approach is developed and validated that replaces the intercept value of 1 with the dynamic increase factor (DIF). This proposal, termed Stress Rate Dependent <i>S</i>–<i>N</i> curves (SRD <i>S</i>–<i>N</i>), is integrated into the fatigue models of Eurocode 2, Model Code 2020, and Zhang, evaluating its accuracy against several experimental datasets. The results demonstrate that considering dynamic strength significantly improves the statistical fit; while conventional regulatory models show poor coefficients of determination (<i>R</i>² &lt; 0.50), the SRD variants increase the average <i>R</i>² to 0.79. Likewise, the root mean square error (RMSE) is practically reduced by half, dropping from 0.54 to 0.34 logarithmic units. The SRD models predict longer fatigue lives for low-cycle fatigue and are more conservative for high-cycle fatigue. Finally, new design expressions are proposed for the SRD models, providing a physically-based predictive framework that optimizes the design of structures subjected to dynamic loading.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental evaluation of an embedded device for measuring local concrete stress under non-uniform shrinkage and creep","authors":"Di Mo,&nbsp;Liuyu Zhang,&nbsp;Long Wang,&nbsp;Hairong He,&nbsp;Zaitie Chen","doi":"10.1617/s11527-026-03272-5","DOIUrl":"10.1617/s11527-026-03272-5","url":null,"abstract":"<div><p>During the hardening and service life of concrete, hydration reactions and moisture migration cause shrinkage and creep deformations. Under constrained conditions, these deformations generate internal stresses, potentially leading to cracking and long-term performance degradation. However, shrinkage and creep stresses are difficult to measure directly. Existing methods primarily rely on deformation measurements combined with theoretical analysis to indirectly calculate stress. To address these challenges, an embedded method for measuring local concrete stress is proposed based on the plane-section assumption and deformation compatibility theory. Its feasibility under non-uniform shrinkage and creep conditions is experimentally evaluated. Five concrete prism specimens were used for sealed, drying, shrinkage, and creep tests. Drying and creep loading both started at an age of 15 days, and the specimens were exposed to an environment of 20 °C and 45% RH. The measured humidity and strain data were used to calibrate the parameters of the moisture diffusion model and the microprestress-solidification (MPS) model, respectively. A sequentially coupled hygro-mechanical finite element model was then established, and the measured results were compared with the numerical results. The results show that the proposed method can effectively reflect the development of local concrete stress under non-uniform shrinkage and creep conditions. Under sealed shrinkage and creep and drying shrinkage and creep conditions, the time-history average relative errors of the measured results with respect to the numerical results were 8.58% and 9.73%, respectively. Since only one validation specimen was tested for each shrinkage and creep condition, this study mainly verifies the feasibility of the method under laboratory conditions. The results indicate that the proposed method can measure local concrete stress based on deformation compatibility and provides a new technical approach for the measurement and analysis of shrinkage and creep stresses in concrete.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating RA-AF and wavelet analysis to characterize the microstructural recovery of self-healing mortar","authors":"Kuan-Hui Li,&nbsp;Tsung-Chin Hou,&nbsp;Feng-Sheng Cheng","doi":"10.1617/s11527-026-03280-5","DOIUrl":"10.1617/s11527-026-03280-5","url":null,"abstract":"<div><p>Cement mortar structures inevitably crack. Hydrophilic crystalline admixtures offer a practical remedy through autonomous repair, yet tracking this internal recovery without destroying the specimen proves difficult. An integrated acoustic emission (AE) framework is proposed to address this challenge. Standard RA–AF (rise time to amplitude versus average frequency) plotting identifies general failure modes well enough. It lacks the precise temporal resolution needed for transient energy shifts, however. To capture these transient features, the dataset is initially filtered using RA–AF parameters, followed by the application of a continuous wavelet transform. Specifically, the durations of secondary (S) waves are monitored to quantitatively characterize physical crack bridging. Experimental setups involved uniaxial compression on both ordinary and crystalline-admixed mortars. Specific damage states were induced by loading samples to 20%, 50%, and 80% of their peak strength, leaving them in high-humidity curing for a week afterward. During the initial stress phase, acoustic parameters shifted predictably from tensile microcracking to shear-dominant sliding, which sharply increased the recorded RA values. Reloading the 20% and 50% pre-damaged groups after curing revealed a striking acoustic reversal. Their RA indicators dropped back into the tensile domain. Concurrently, the wavelet analysis confirmed noticeably shorter S-wave delays. These signal changes are attributed to restricted sliding along previously fractured planes—direct evidence of material healing. The 80% pre-damage group exhibited no such recovery, marking a clear functional ceiling for this restoration mechanism. The data confirm that adding these crystalline agents stabilizes the cement matrix against recurring loads by actively delaying the progression of major shear faults.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 8","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}