We have developed a software system that takes standard electrocardiogram (ECG) input and interprets this input along with user-defined and automatically defined markers to diagnose myocardial infarctions (MI). These pathologies are then automatically represented within a volumetric model of the heart. Over a period of six months 30 patients were monitored using a digital ECG system and this information was used to test and develop our system. It was found that the STEMIs (ST segment Elevation MI) were successfully diagnosed, however NSTEMIs (Non-STEMI), although correctly interpreted, were more ambiguous due to the fact that T wave inversions are sometimes seen on normal ECGs. Control ECGs of normal hearts were also taken. The system correctly interpreted this data as being normal. A standard voxel-count metric was developed so that future work in MI monitoring will be possible. The toolkit was found to be beneficial for three possible uses, as a diagnostic tool for clinicians, as a teaching tool for students and also as an information tool for the patient.
{"title":"A VR toolkit for the diagnosis and monitoring of myocardial infarctions","authors":"J. Ryan, C. O'Sullivan, C. Bell, N. Mulvihill","doi":"10.1109/VG.2005.194097","DOIUrl":"https://doi.org/10.1109/VG.2005.194097","url":null,"abstract":"We have developed a software system that takes standard electrocardiogram (ECG) input and interprets this input along with user-defined and automatically defined markers to diagnose myocardial infarctions (MI). These pathologies are then automatically represented within a volumetric model of the heart. Over a period of six months 30 patients were monitored using a digital ECG system and this information was used to test and develop our system. It was found that the STEMIs (ST segment Elevation MI) were successfully diagnosed, however NSTEMIs (Non-STEMI), although correctly interpreted, were more ambiguous due to the fact that T wave inversions are sometimes seen on normal ECGs. Control ECGs of normal hearts were also taken. The system correctly interpreted this data as being normal. A standard voxel-count metric was developed so that future work in MI monitoring will be possible. The toolkit was found to be beneficial for three possible uses, as a diagnostic tool for clinicians, as a teaching tool for students and also as an information tool for the patient.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"188 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114430298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we study the interval segmentation and direct rendering of time-varying volumetric data to provide a more effective and interactive volume rendering of time-varying structured and unstructured grids. Our segmentation is based upon intervals within the scalar field between time steps, producing a set of geometrically defined time-varying interval volumes. To construct the time-varying interval volumes, we cast the problem one dimension higher, using a five-dimensional isocontour construction for interactive computation or segmentation. The key point of this paper is how to render the time-varying interval volumes directly. We directly render the 4D interval volumes by projecting the 4D simplices onto 3D, decomposing the projected 4-simplices to 3-simplices and then rendering them using a modified hardware-implemented projected tetrahedron method. In this way, we can see how interval volumes change with the time in one view. The algorithm is independent of the topology of the polyhedral cells comprising the grid, and thus offers an excellent enhancement to the volume rendering of time-varying unstructured grids. Another advantage of this algorithm is that various volumetric and surface boundaries can be embedded into the time-varying interval volumes.
{"title":"Time-varying interval volumes","authors":"Caixia Zhang, Daqing Xue, R. Crawfis, R. Wenger","doi":"10.2312/VG/VG05/099-107","DOIUrl":"https://doi.org/10.2312/VG/VG05/099-107","url":null,"abstract":"In this paper, we study the interval segmentation and direct rendering of time-varying volumetric data to provide a more effective and interactive volume rendering of time-varying structured and unstructured grids. Our segmentation is based upon intervals within the scalar field between time steps, producing a set of geometrically defined time-varying interval volumes. To construct the time-varying interval volumes, we cast the problem one dimension higher, using a five-dimensional isocontour construction for interactive computation or segmentation. The key point of this paper is how to render the time-varying interval volumes directly. We directly render the 4D interval volumes by projecting the 4D simplices onto 3D, decomposing the projected 4-simplices to 3-simplices and then rendering them using a modified hardware-implemented projected tetrahedron method. In this way, we can see how interval volumes change with the time in one view. The algorithm is independent of the topology of the polyhedral cells comprising the grid, and thus offers an excellent enhancement to the volume rendering of time-varying unstructured grids. Another advantage of this algorithm is that various volumetric and surface boundaries can be embedded into the time-varying interval volumes.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129706855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Texture mapping is an extremely powerful and flexible tool for adding complex surface detail to an object. This paper introduces a method of surface texturing and hypertexturing complex volumetric objects in real-time. We employ distance field volume representations, texture based volume rendering and procedural texturing techniques with Shader Model 2.0 flexible programmable graphics hardware. We aim to provide a flexible cross-platform, non vendor specific implementation.
纹理映射是一个非常强大和灵活的工具，可以为物体添加复杂的表面细节。本文介绍了一种复杂体体对象的实时表面纹理化和超纹理化方法。我们采用距离场体表示，基于纹理的体渲染和程序纹理技术，使用Shader Model 2.0灵活的可编程图形硬件。我们的目标是提供一个灵活的跨平台，非特定于供应商的实现。
{"title":"Texturing and hypertexturing of volumetric objects","authors":"Chris M. Miller, Mark W. Jones","doi":"10.2312/VG/VG05/117-125","DOIUrl":"https://doi.org/10.2312/VG/VG05/117-125","url":null,"abstract":"Texture mapping is an extremely powerful and flexible tool for adding complex surface detail to an object. This paper introduces a method of surface texturing and hypertexturing complex volumetric objects in real-time. We employ distance field volume representations, texture based volume rendering and procedural texturing techniques with Shader Model 2.0 flexible programmable graphics hardware. We aim to provide a flexible cross-platform, non vendor specific implementation.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127588299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a new parallel multiresolution volume rendering framework for large-scale time-varying data visualization using the wavelet-based time-space partitioning (WTSP) tree. Utilizing the wavelet transform, a large-scale time-varying data set is converted into a space-time multiresolution data hierarchy, and is stored in a time-space partitioning (TSP) tree. To eliminate the parent-child data dependency for reconstruction and achieve load-balanced rendering, we design an algorithm to partition the WTSP tree and distribute the wavelet-compressed data along hierarchical space-filling curves with error-guided bucketization. At run time, the WTSP tree is traversed according to the user-specified time step and tolerances of both spatial and temporal errors. Data blocks of different spatio-temporal resolutions are reconstructed and rendered to compose the final image in parallel. We demonstrate that our algorithm can reduce the run-time communication cost to a minimum and ensure a well-balanced workload among processors when visualizing gigabytes of time-varying data on a PC cluster.
{"title":"A multiresolution volume rendering framework for large-scale time-varying data visualization","authors":"Chaoli Wang, Jinzhu Gao, Liya Li, Han-Wei Shen","doi":"10.2312/VG/VG05/011-019","DOIUrl":"https://doi.org/10.2312/VG/VG05/011-019","url":null,"abstract":"We present a new parallel multiresolution volume rendering framework for large-scale time-varying data visualization using the wavelet-based time-space partitioning (WTSP) tree. Utilizing the wavelet transform, a large-scale time-varying data set is converted into a space-time multiresolution data hierarchy, and is stored in a time-space partitioning (TSP) tree. To eliminate the parent-child data dependency for reconstruction and achieve load-balanced rendering, we design an algorithm to partition the WTSP tree and distribute the wavelet-compressed data along hierarchical space-filling curves with error-guided bucketization. At run time, the WTSP tree is traversed according to the user-specified time step and tolerances of both spatial and temporal errors. Data blocks of different spatio-temporal resolutions are reconstructed and rendered to compose the final image in parallel. We demonstrate that our algorithm can reduce the run-time communication cost to a minimum and ensure a well-balanced workload among processors when visualizing gigabytes of time-varying data on a PC cluster.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116362727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The coronary arteries are essential for the proper function of the human heart. However, they are generally difficult to segment in volume datasets separately from the other blood-filled cavities of the heart. The major reason for these difficulties is the lack of sufficient spatial resolution and partial volume effects. In this paper, we present a method to mark the coronary arteries by a virtual endoscopic traversal. Virtual endoscopy enables a significantly easier visual identification of the blood vessels in comparison to outside views or slice-by-slice examination methods. Furthermore, we use this marking as a scaffold for the actual segmentation of the coronary arteries.
{"title":"Scaffolding-based segmentation of coronary vascular structures","authors":"D. Bartz, S. Lakare","doi":"10.2312/VG/VG05/047-054","DOIUrl":"https://doi.org/10.2312/VG/VG05/047-054","url":null,"abstract":"The coronary arteries are essential for the proper function of the human heart. However, they are generally difficult to segment in volume datasets separately from the other blood-filled cavities of the heart. The major reason for these difficulties is the lack of sufficient spatial resolution and partial volume effects. In this paper, we present a method to mark the coronary arteries by a virtual endoscopic traversal. Virtual endoscopy enables a significantly easier visual identification of the blood vessels in comparison to outside views or slice-by-slice examination methods. Furthermore, we use this marking as a scaffold for the actual segmentation of the coronary arteries.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115958529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Splatting is a popular technique for volume rendering, where voxels are represented by Gaussian kernels, whose pre-integrated footprints are accumulated to form the image. Splatting has been mainly used to render pre-shaded volumes, which can result in significant blurring in zoomed views. This can be avoided in the image-aligned splatting scheme, where one accumulates kernel slices into equi-distant, parallel sheet buffers, followed by classification, shading, and compositing. In this work, we attempt to evolve this algorithm to the next level: GPU (graphics processing unit) based acceleration. First we describe the challenges that the highly parallel "Gather" architecture of modern GPUs poses to the "Scatter" based nature of a splatting algorithm. We then describe a number of strategies that exploit newly introduced features of the latest-generation hardware to address these limitations. Two crucial operations to boost the performance in image-aligned splatting are the early elimination of hidden splats and the skipping of empty buffer-space. We describe mechanisms which take advantage of the early z-culling hardware facilities to accomplish both of these operations efficiently in hardware.
{"title":"GPU accelerated image aligned splatting","authors":"N. Neophytou, K. Mueller","doi":"10.2312/VG/VG05/197-205","DOIUrl":"https://doi.org/10.2312/VG/VG05/197-205","url":null,"abstract":"Splatting is a popular technique for volume rendering, where voxels are represented by Gaussian kernels, whose pre-integrated footprints are accumulated to form the image. Splatting has been mainly used to render pre-shaded volumes, which can result in significant blurring in zoomed views. This can be avoided in the image-aligned splatting scheme, where one accumulates kernel slices into equi-distant, parallel sheet buffers, followed by classification, shading, and compositing. In this work, we attempt to evolve this algorithm to the next level: GPU (graphics processing unit) based acceleration. First we describe the challenges that the highly parallel \"Gather\" architecture of modern GPUs poses to the \"Scatter\" based nature of a splatting algorithm. We then describe a number of strategies that exploit newly introduced features of the latest-generation hardware to address these limitations. Two crucial operations to boost the performance in image-aligned splatting are the early elimination of hidden splats and the skipping of empty buffer-space. We describe mechanisms which take advantage of the early z-culling hardware facilities to accomplish both of these operations efficiently in hardware.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129615158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose a GPU-based object-order ray-casting algorithm for the rendering of large volumetric datasets, such as the Visible Human CT datasets. A volumetric dataset is decomposed into small sub-volumes, which are then organized using a min-max octree structure. The small sub-volumes are stored in the leaf nodes of the min-max octree, which are also called cells. The cells are classified using a transfer function, and the visible cells are then loaded into the video memory or the AGP memory. The cells are sorted and projected onto the image plane front to back. The cell projection is implemented using a volumetric ray-casting algorithm on the GPU. In order to make the cell projection more efficient, we devise a propagation method to sort cells into layers. The cells within the same layer are projected at the same time. We demonstrate the efficiency of our algorithm using the visible human datasets and a segmented photographic brain dataset on commodity PCs.
{"title":"GPU-based object-order ray-casting for large datasets","authors":"Wei Hong, Feng Qiu, A. Kaufman","doi":"10.2312/VG/VG05/177-185","DOIUrl":"https://doi.org/10.2312/VG/VG05/177-185","url":null,"abstract":"We propose a GPU-based object-order ray-casting algorithm for the rendering of large volumetric datasets, such as the Visible Human CT datasets. A volumetric dataset is decomposed into small sub-volumes, which are then organized using a min-max octree structure. The small sub-volumes are stored in the leaf nodes of the min-max octree, which are also called cells. The cells are classified using a transfer function, and the visible cells are then loaded into the video memory or the AGP memory. The cells are sorted and projected onto the image plane front to back. The cell projection is implemented using a volumetric ray-casting algorithm on the GPU. In order to make the cell projection more efficient, we devise a propagation method to sort cells into layers. The cells within the same layer are projected at the same time. We demonstrate the efficiency of our algorithm using the visible human datasets and a segmented photographic brain dataset on commodity PCs.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130994288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Very large irregular-grid volume data sets are typically represented as tetrahedral mesh and require substantial disk I/O and rendering computation. One effective way to reduce this demanding resource requirement is compression. Previous research showed how rendering and decompression of a losslessly compressed irregular-grid data set can be integrated into a one-pass computation. This work, advances the state of the art one step further by showing that a losslessly compressed irregular volume data set can be simplified while it is being decompressed and that simplification, decompression, and rendering can again be integrated into a pipeline that requires only a single pass through the data sets. Since simplification is a form of lossy compression, the on-the-fly volume simplification algorithm provides a powerful mechanism to dynamically create versions of a tetrahedral mesh at multiple resolution levels directly from its losslessly compressed representation, which also corresponds to the finest resolution level. In particular, an irregular-grid volume Tenderer can exploit this multi-resolution representation to maintain interactivity on a given hardware/software platform by automatically adjusting the amount of rendering computation that could be afforded, or performing so called time-critical rendering. The proposed tetrahedral mesh simplification algorithm and its integration with volume decompression and rendering has been successfully implemented in the Gatun system. Performance measurements on the Gatun prototype show that simplification only adds less than 5% of performance overhead on an average and with multi-resolution pre-simplification the end-to-end rendering delay indeed decreases in an approximately linear fashion with respect to the simplification ratio.
{"title":"An integrated processing pipeline for irregular volume data","authors":"Chuan-Kai Yang, T. Chiueh","doi":"10.1109/VG.2005.194109","DOIUrl":"https://doi.org/10.1109/VG.2005.194109","url":null,"abstract":"Very large irregular-grid volume data sets are typically represented as tetrahedral mesh and require substantial disk I/O and rendering computation. One effective way to reduce this demanding resource requirement is compression. Previous research showed how rendering and decompression of a losslessly compressed irregular-grid data set can be integrated into a one-pass computation. This work, advances the state of the art one step further by showing that a losslessly compressed irregular volume data set can be simplified while it is being decompressed and that simplification, decompression, and rendering can again be integrated into a pipeline that requires only a single pass through the data sets. Since simplification is a form of lossy compression, the on-the-fly volume simplification algorithm provides a powerful mechanism to dynamically create versions of a tetrahedral mesh at multiple resolution levels directly from its losslessly compressed representation, which also corresponds to the finest resolution level. In particular, an irregular-grid volume Tenderer can exploit this multi-resolution representation to maintain interactivity on a given hardware/software platform by automatically adjusting the amount of rendering computation that could be afforded, or performing so called time-critical rendering. The proposed tetrahedral mesh simplification algorithm and its integration with volume decompression and rendering has been successfully implemented in the Gatun system. Performance measurements on the Gatun prototype show that simplification only adds less than 5% of performance overhead on an average and with multi-resolution pre-simplification the end-to-end rendering delay indeed decreases in an approximately linear fashion with respect to the simplification ratio.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121812274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lately, new methods for the acquisition of time-varying, volumetric data for photo-realistic rendering of semi-transparent, volumetric phenomena like fire and smoke have been developed. This paper presents a wavelet-coding and rendering approach for these volumetric sequences that exploits spatial as well as temporal coherence in the data. A space partitioning tree allows for efficient storage and real-time rendering of dynamic, volumetric data on common PC hardware.
{"title":"Volumetric reconstruction, compression and rendering of natural phenomena from multi-video data","authors":"L. Ahrenberg, Ivo Ihrke, M. Magnor","doi":"10.2312/VG/VG05/083-090","DOIUrl":"https://doi.org/10.2312/VG/VG05/083-090","url":null,"abstract":"Lately, new methods for the acquisition of time-varying, volumetric data for photo-realistic rendering of semi-transparent, volumetric phenomena like fire and smoke have been developed. This paper presents a wavelet-coding and rendering approach for these volumetric sequences that exploits spatial as well as temporal coherence in the data. A space partitioning tree allows for efficient storage and real-time rendering of dynamic, volumetric data on common PC hardware.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126324863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There has been considerable interest in modeling realistic subsurface light scattering in materials such as marble, human skin, or clouds. Many of these models provide a solution for the transport equation in a homogeneous or layered scattering media. The model we present here exploits a diffusion mechanism to provide a simpler solution to the transport equation. Treating light flux as current we can use circuit analysis techniques and linear systems to solve directly for the steady state transport equation and ignore the transient values. Thus our model can simulate light transport in heterogeneous materials and complex geometry.
{"title":"A simplified model for inhomogeneous subsurface scattering","authors":"R. Sharp, R. Machiraju","doi":"10.2312/VG/VG05/063-071","DOIUrl":"https://doi.org/10.2312/VG/VG05/063-071","url":null,"abstract":"There has been considerable interest in modeling realistic subsurface light scattering in materials such as marble, human skin, or clouds. Many of these models provide a solution for the transport equation in a homogeneous or layered scattering media. The model we present here exploits a diffusion mechanism to provide a simpler solution to the transport equation. Treating light flux as current we can use circuit analysis techniques and linear systems to solve directly for the steady state transport equation and ignore the transient values. Thus our model can simulate light transport in heterogeneous materials and complex geometry.","PeriodicalId":443333,"journal":{"name":"Fourth International Workshop on Volume Graphics, 2005.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126593281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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