Biomedical engineering advances最新文献

{"title":"Effect of nutrient-based alloying elements on biodegradable magnesium alloys: Evolution, challenges, and strategies for orthopaedic applications","authors":"Pradeep Raja C ,&nbsp;Karthik Babu N B ,&nbsp;N S Balaji ,&nbsp;A Saikiran ,&nbsp;Rajesh Kannan A","doi":"10.1016/j.bea.2025.100161","DOIUrl":"10.1016/j.bea.2025.100161","url":null,"abstract":"<div><div>In recent years, magnesium (Mg) alloys have become increasingly popular in orthopaedic applications as biomaterials. Unlike traditional implants such as cobalt-chrome, stainless steel, and titanium alloys, Mg alloys offer notable advantages, including outstanding biodegradability and biocompatibility. This characteristic eliminates the need for a second surgery after the bone healing process, a distinct advantage for patients. Additionally, Mg alloys address the issue of stress shielding, a common problem with other materials. Despite facilitating the osteoconductive process, their rapid degradation in physiological conditions poses a challenge, compromising mechanical strength and hindering bone tissue recovery. This degradation leads to tissue alkalization and the formation of hydrogen bubbles, hindering the recovery rate of bone tissues and limiting the applications of Mg alloys. And the rapid degradation of magnesium alloys in physiological conditions accelerates corrosion and compromises mechanical integrity, affecting their load-bearing capacity. Enhancing structural integrity is essential to ensure sufficient strength during bone healing, aligning the degradation rate with the physiological process. To reduce the fast degradation rate, extensive research has been conducted in mechanical and corrosion-based studies, focusing on altering the biomedical performance of Mg alloys through alloying elements, processing routes, and other strategies. One approach involves mixing pure magnesium with nutrient materials and reinforcing it with hydroxyapatite. These modifications aim to match the corrosion rate with the healing rate of bone tissue. This paper explores the significance of biodegradable Mg alloys, providing a comprehensive review of their evolution and development. It emphasises enhancing the mechanical and corrosion properties of Mg alloys by adjusting the percentage of alloying elements, employing specific processing strategies, and incorporating reinforcements. The discussion particularly emphasizes the impact of nutrient elements, binary and ternary alloys, as well as hydroxyapatite composites of magnesium-based alloys in physiological conditions. Furthermore, the review highlights emerging technologies like Laser Powder Bed Fusion (LPBF), offering a general perspective on improving the mechanical and corrosion properties of Mg alloys for orthopaedic use.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100161"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polycarbonate/antibacterial blend nanocomposites in material extrusion 3D printing: Thermomechanical response, rheology, and biocidal metrics","authors":"Markos Petousis ,&nbsp;Nektarios K. Nasikas ,&nbsp;Vassilis Papadakis ,&nbsp;Maria Spyridaki ,&nbsp;Evangelos Sfakiotakis ,&nbsp;Amalia Moutsopoulou ,&nbsp;Apostolos Argyros ,&nbsp;Evgenia Dimitriou ,&nbsp;Nikolaos Michailidis ,&nbsp;Nectarios Vidakis","doi":"10.1016/j.bea.2025.100160","DOIUrl":"10.1016/j.bea.2025.100160","url":null,"abstract":"<div><div>The motivation of the research was to introduce nanocomposites with the polycarbonate (PC) thermoplastic as the matrix material, with biocidal capabilities and improved mechanical performance for the material extrusion (MEX) additive manufacturing (AM) technique. Such nanocomposites have not been investigated so far. They would exploit the use of the PC thermoplastic and the MEX AM method in various types of applications with respective specifications, such as in the defense or security sector, in which PC is a popular thermoplastic already. We successfully synthesized a series of PC/antibacterial nanocomposites for the material extrusion 3D printing technique. The PC/antibacterial nanocomposites consisted of 2wt. % antibacterial nanopowder intervals (2–12wt. %). The as-prepared PC/antibacterial nanocomposite batches were converted into filaments and afterward 3D printed. The 3D printed materials were subjected to a series of experimental tests to determine their mechanical, thermal, rheological, physicochemical, morphological, structural, and biocidal properties, following the respective standards. The biocidal characterization of the various PC/antibacterial nanocomposites (agar well diffusion method, Mcfarland protocol) provided evidence that both the enhanced mechanical properties (29.1 % improvement of the tensile strength with 4 wt. % nanopowder loading) and biocidal activity (gram-positive Staphylococcus aureus and gram-negative <em>Escherichia coli</em> were tested) of the 3D printed PC/antibacterial nanocomposites are feasible. We have concluded that the maximization of the above-mentioned multifunctionalities can be achieved for moderate loadings of antibacterial nanopowder while the 3D printing of such PC/Antibacterial nanocomposites produces high-quality parts which can find important applications in the Defence and Security domain but also “dual – use” applications in the civil domain.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100160"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additive manufacturing of silicone for biomedical applications","authors":"Deon Johan de Beer ,&nbsp;Thywill Cephas Dzogbewu ,&nbsp;Van Der Walt Kobus","doi":"10.1016/j.bea.2025.100158","DOIUrl":"10.1016/j.bea.2025.100158","url":null,"abstract":"<div><div>The manufacturing of silicone-based elastomers has been the center of research for several decades and the renaissance of the manufacturing industry via additive manufacturing (AM) seems to verve the hype of the widespread industrial applications of silicone by providing solutions to the challenges of manufacturing components with the material through the classical manufacturing approach. The unique flexibility of silicone combined with the geometrical precision printing capability of the AM has enabled the manufacturing of intricate microfluidics structures with surface functionalization properties, bionic fingers, wearable devices, bespoke nasal prostheses, customized sports mouth guards, heart valves, etc. The impending challenges such as the formulation of the silicone resin with the right viscosity, slow curing process, shear-thinning, printing of overhanging structures, small dimensions, printing speed, poor resolution, etc. are paving the way and becoming the driving force for progressive innovative research.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100158"},"PeriodicalIF":0.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Translation of single channel electro encephalic signals into limb motion","authors":"A.B.R. Lara ,&nbsp;Oscar E. Ruiz ,&nbsp;L.O. Araujo Junior ,&nbsp;F.P. Bhering","doi":"10.1016/j.bea.2025.100154","DOIUrl":"10.1016/j.bea.2025.100154","url":null,"abstract":"<div><div>Neural prostheses (NPs) are devices that can translate brainwaves into motion. The non-invasive multi-channel headset used in the study of Brain–Computer Interface (BCI) systems for the development of NPs, presents high resolution in data collection, but also presents high computing expenses and hardware costs. To overcome the barrier of the costs and present an accessible technology for these studies, this manuscript presents the implementation of a method that uses a single-channel headset to sample the Electro Encephalo Graph (EEG) wave. The headset provides 8 individual brain waves (delta, theta, low alpha, high alpha, low beta, high beta, low gamma, mid gamma), operating in their characteristic frequency intervals. A Multi-layer Perceptron (MLP) was trained with the Alpha and Beta waves (4 signals), reaching a <span><math><mrow><mn>73</mn><mo>,</mo><mn>9</mn><mtext>%</mtext></mrow></math></span> accuracy rate for detecting the movement (open/close) of the subject’s right hand. The conclusion on the subject hand status is fed into a kinematic (Denavit Hartenberg) model of the hand, to simulate the opening/ closing of a robotic hand. The results confirm the usability of the single-channel headset to extract information from the motor cortex for the development of cheaper and more accessible NPs. The advantages of this method are: (a) lower hardware expense and (b) lower computing load. The disadvantages of our approach lie in the time needed for the 15 s to react to the real-time patient brain signal and to produce the Open/Close command to the Neural Prosthesis. Future endeavors include the online usage of the trained NN by the subject. An additional interest domain is the usage of intention-of-movement brain waves for forecasting.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100154"},"PeriodicalIF":0.0,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding motor execution and motor imagery from EEG with deep learning and source localization","authors":"Sina Makhdoomi Kaviri,&nbsp;Ramana Vinjamuri","doi":"10.1016/j.bea.2025.100156","DOIUrl":"10.1016/j.bea.2025.100156","url":null,"abstract":"<div><div>The use of noninvasive imaging techniques has become pivotal in understanding human brain functionality. While modalities like MEG and fMRI offer excellent spatial resolution, their limited temporal resolution, often measured in seconds, restricts their application in real-time brain activity monitoring. In contrast, EEG provides superior temporal resolution, making it ideal for real-time applications in brain–computer interface systems. In this study, we combined deep learning with source localization to classify two motor task types: motor execution and motor imagery. For motor imagery tasks—left hand, right hand, both feet, and tongue—we transformed EEG signals into cortical activity maps using Minimum Norm Estimation (MNE), dipole fitting, and beamforming. These were analyzed with a custom ResNet CNN, where beamforming achieved the highest accuracy of 99.15%, outperforming most traditional methods. For motor execution involving six types of reach-and-grasp tasks, beamforming achieved 90.83% accuracy compared to 56.39% from a sensor domain approach (ICA + PSD + TSCR-Net). These results underscore the significant advantages of integrating source localization with deep learning for EEG-based motor task classification, demonstrating that source localization techniques greatly enhance classification accuracy compared to sensor domain approaches.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100156"},"PeriodicalIF":0.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conducting an experimental study on the interaction between mesenchymal stem cells and chicken neck derived ECM In Vitro.","authors":"Maryam Saedi ,&nbsp;Yasin Ghabool ,&nbsp;Nasser Mahdavi-Shahri ,&nbsp;Amin Tavassoli","doi":"10.1016/j.bea.2025.100155","DOIUrl":"10.1016/j.bea.2025.100155","url":null,"abstract":"<div><div>Three-dimensional scaffolds play a critical role in tissue engineering. Scaffolds fabricated from decellularized tissues, which retain the extracellular matrix (ECM), represent a promising option for natural scaffolds. These scaffolds have the potential to support cell adhesion and proliferation. This research was conducted to create diverse natural scaffolds through the decellularization of chicken neck tissue. The neck tissue is considered a favorable structure for investigating cell behaviors, such as migration and division. A combination of three decellularization processes-physical, chemical, and enzymatic was employed. These procedures involved subjecting the tissue to gradual and rapid freezing-thawing, followed by treatment with trypsin. The chicken neck tissue was decellularized using sodium dodecyl sulfate (SDS). Following histological examinations to verify successful decellularization. Mesenchymal stem cells (MSCs) obtained from bone-marrow of rat tissue were cultivated on the scaffold derived from the decellularized matrix. Histological analyses revealed that the most effective decellularization method involved rapidly freezing and thawing the samples in liquid nitrogen, followed by treatment with a 2% solution of SDS and a 0.25% trypsin solution. This method successfully eliminated cells while preserving collagen and elastin proteins. Furthermore, histological examinations and fluorescence microscopy demonstrated the interaction between the scaffold and MSCs. The movement of stem cells on the neck tissue scaffold was tracked on the 7th and 14th days of culture. The results of this study, which examined the fluorescence, structure, and chemical composition of the decellularized extracellular matrix of neck tissue, indicated that it could promote MSCs attachment, movement, and polarity.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100155"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evolution of Electrovestibulography technique and safety considerations","authors":"Zeinab A. Dastgheib ,&nbsp;Chathura Kumaragamage ,&nbsp;Brian J. Lithgow ,&nbsp;Zahra K. Moussavi","doi":"10.1016/j.bea.2025.100157","DOIUrl":"10.1016/j.bea.2025.100157","url":null,"abstract":"<div><div>Over the past decade, the number of papers reporting the use of the Electrovestibulography (EVestG) technique has tripled compared to the previous decade. Moreover, EVestG has been employed in clinical trials for diagnostic purposes and monitoring treatment efficacy. The key drivers behind the expansion of such work could be linked to both the progress achieved in the EVestG technical development as well as the fact that EVestG has proved to be a safe and tolerable technology with promising diagnostic capabilities. Compared to existing vestibular and neurophysiological assessments, EVestG provides a non-invasive and objective method to directly measure vestibular responses and indirectly assess neurophysiological brain activity, with potential for early diagnosis. This contribution reviews the technical evolution and safety considerations of EVestG over the last decade. Areas of development that together contributed to the current state of the art are discussed. These include the design of low-noise electrodes, the electrode placement protocol, and improvements in signal acquisition during recording. Additionally, participant attrition rates and withdrawal reasons are presented. Findings highlight advancements in signal quality, user comfort, and diagnostic reliability, reinforcing EVestG's clinical viability. Lastly, potential developments and challenges toward a miniaturised and portable EVestG technology are discussed.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100157"},"PeriodicalIF":0.0,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of a conventional cantilever abutment and innovative double abutment in dental implant prosthesis: A finite element analysis study","authors":"Luciana Silva Colepícolo ,&nbsp;Paulo Henrique Vieira Magalhães ,&nbsp;Maria Auxiliadora Mourão Martinez ,&nbsp;Luís Otávio Miranda Cota ,&nbsp;Rafael Paschoal Esteves Lima ,&nbsp;Lucas Fernandes Sousa Pessoa ,&nbsp;Guilherme Augusto Oliveira ,&nbsp;Fernando Oliveira Costa","doi":"10.1016/j.bea.2025.100151","DOIUrl":"10.1016/j.bea.2025.100151","url":null,"abstract":"<div><div>The innovative double paraboloid abutment (DA) in dental implant prosthesis is based on the new concept of Biodynamic Optimized Peri-implant Tissue (BOiT) and was introduced in a human case series report with follow-ups ranging from 3 to 12 years. This study aimed to evaluate the influence of two structural designs: the innovative DA and a distal conventional cantilever (CC) in fixed prostheses retained by a single dental implant. The evaluation focused on stress and strain distributions in bone tissue (cortical and medullary), as well as stress distribution in the abutments, UCLA, implants, and retaining screws under axial and oblique loading, using 3D finite element analysis. Each model consisted of a bone block representing the area from the right second premolar to the first molar, with one internal hexagon implant (4.0 × 10 mm) supporting a fixed dental prosthesis of two elements. Forces of 100 N were applied in both axial and oblique directions (at 30° in the Y direction). The von Mises criterion was used to assess maximum principal stress values and microstrain. Simulations were created using ANSYS mechanical software. After applying the loads and obtaining the stress results, using the same materials for each of the modeled parts, as well as bone and identical loads, it was observed that the DA design yielded more favorable results than the cantilever. The DA showed significantly lower stress levels and better strain distributions, indicating a more favorable biomechanical interaction between structures. These findings suggest that DA designs may reduce stress concentrations and potentially minimize the risk of clinical complications compared to traditional CC designs, leading to improved long-term implant stability and success rates in patients missing two adjacent dental elements, supported by a single osseointegrated implant.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100151"},"PeriodicalIF":0.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining the optimal design parameters for gyroids using computational fluid dynamics analysis under a non-Newtonian perfusion system","authors":"Abhisek Gupta ,&nbsp;Masud Rana ,&nbsp;Nitesh Mondal","doi":"10.1016/j.bea.2025.100153","DOIUrl":"10.1016/j.bea.2025.100153","url":null,"abstract":"<div><div>A gyroid scaffold provides a biologically acceptable environment for tissue growth and regeneration of injured tissue and organs. The effective waste and nutrient transport between implanted scaffolds and surrounding tissue remains a key challenge in bone tissue engineering. Consequently, this study aims to assess the flow transport parameters of gyroid scaffolds, focusing on their porous structures, which are commonly used as scaffold units in recent times. In this study, a computational fluid dynamics analysis was done with the four types of gyroids to identify the optimum scaffold for the better growth or regeneration of tissue. The different hydrodynamics parameters were observed for both Newtonian and non-Newtonian fluids for different gyroid structures. The variation of wall shear stress (WSS) and permeability were studied and compared for both Newtonian and non-Newtonian fluids between gyroids. Later, a sinusoidal non-Newtonian flow was applied to the gyroids to examine the responses due to pulsatile flow. The results showed that non-Newtonian flow generates higher WSS and lower permeability than Newtonian flow within gyroids in each case. Furthermore, additional regions within the scaffold were found to fall within the favorable zone for bone growth under pulsatile flow conditions. The findings of this study hold promise for enhancing scaffold design in tissue engineering and identifying ways to promote optimal cell seeding areas within the scaffold in vitro.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100153"},"PeriodicalIF":0.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding and generating synergy-based hand movements using electroencephalography during motor execution and motor imagery","authors":"Dingyi Pei,&nbsp;Ramana Vinjamuri","doi":"10.1016/j.bea.2025.100152","DOIUrl":"10.1016/j.bea.2025.100152","url":null,"abstract":"<div><div>Brain-machine interfaces (BMIs) have proven valuable in motor control and rehabilitation. Motor imagery (MI) is a key tool for developing BMIs, particularly for individuals with impaired limb function. Motor planning and internal programming are hypothesized to be similar during motor execution (ME) and motor imagination. The anatomical and functional similarity between motor execution and motor imagery suggests that synergy-based movement generation can be achieved by extracting neural correlates of synergies or movement primitives from motor imagery. This study explored the feasibility of synergy-based hand movement generation using electroencephalogram (EEG) from imagined hand movements. Ten subjects participated in an experiment to imagine and execute hand movement tasks while their hand kinematics and neural activity were recorded. Hand kinematic synergies derived from executed movements were correlated with EEG spectral features to create a neural decoding model. This model was used to decode the weights of kinematic synergies from motor imagery EEG. These decoded weights were then combined with kinematic synergies to generate hand movements. As a result, the decoding model successfully predicted hand joint angular velocity patterns associated with grasping different objects. This adaptability demonstrates the model's ability to capture the motor control characteristics of ME and MI, advancing our understanding of MI-based neural decoding. The results hold promise for potential applications in noninvasive synergy-based neuromotor control and rehabilitation for populations with upper limb motor disabilities.</div></div>","PeriodicalId":72384,"journal":{"name":"Biomedical engineering advances","volume":"9 ","pages":"Article 100152"},"PeriodicalIF":0.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}