Photons Plus Ultrasound: Imaging and Sensing 2019最新文献

{"title":"Multifocal photoacoustic microscopy through an ergodic relay (Conference Presentation)","authors":"Yang Li, T. T. Wong, Junhui Shi, H. Hsu, Lihong V. Wang","doi":"10.1117/12.2513502","DOIUrl":"https://doi.org/10.1117/12.2513502","url":null,"abstract":"To date, most optical-resolution photoacoustic microscopy (OR-PAM) systems rely on mechanical scanning with confocally aligned optical excitation and ultrasonic detection. As a result, the imaging speed of these systems is limited by the scanning speed. Although several multifocal OR-PA computed tomography (MFOR-PACT) systems had been developed to address this limitation, they were hindered by the complex design in a constrained physical space. Here, we present a two-dimensional (2D) MFOR-PAM system based on a 2D microlens array and an acoustic ergodic relay. This system is able to detect PA signals generated from 400 optical foci in parallel with a single-element transducer, and then raster scan the optical foci patterns to form an image. This system has improved the imaging resolution of a conventional photoacoustic ergodic relay system from 220 μm to 13 μm. Moreover, this system has reduced the imaging time of a conventional OR-PAM system at the same resolution and laser repetition rate by 400 times. We demonstrated the ability of the system with both in vitro and in vivo experiments.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124121323","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}

{"title":"Improved light delivery in biological tissue using HIFU heating tunnel: photoacoustic verification (Conference Presentation)","authors":"Zong-Han Hsieh, C. Yeh, Meng-Lin Li","doi":"10.1117/12.2507771","DOIUrl":"https://doi.org/10.1117/12.2507771","url":null,"abstract":"Optical imaging and photothermal therapy have been applied in biomedical field for decades. However, the strong scattering of light in biological tissue hinders the focal light delivery and thus restricts their clinical applications because of the resultant limited penetration. We hypothesize that the photon scattering is reduced in the cylindrical heating zone of high intensity focused ultrasound (HIFU) and thus the efficiency of light delivery can be improved via transmission of light through the heating cylindrical tunnel, enabling photoacoustic signal enhancement at the targeted region. In this study, Monte Carlo simulation and intralipid-phantom experiments were used to verify our hypothesis. The thermal effect could increase the laser fluence at the targeted region by at least 10% no matter in the simulation or the experiment. Similar results were also presented in the measured photoacoustic signal. Note that special care had been taken to keep the Gruneisen coefficient at the targeted region constant so that the photoacoustic signal change solely depended on delivered laser fluence. In addition, the simulation results indicate that with the local cylindrical heating tunnel, the fluence at the targeted region is at least 10% higher than that with global heating, suggesting that HIFU heating tissue tunnel owns the potential in enhancing the light delivery efficiency, the light penetration and thus the photoacoustic signal at the targeted region as well. It is expected that our finding is not only applicable to photoacoustic imaging but also photothermal therapy which also requires more focal light delivery.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125462203","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}

{"title":"OCT-guided integrated multimodal photoacoustic microscopy for fast scanning speed and large scanning area (Conference Presentation)","authors":"A. Dadkhah, S. Jiao","doi":"10.1117/12.2508571","DOIUrl":"https://doi.org/10.1117/12.2508571","url":null,"abstract":"Acquiring more comprehensive information of biological samples requires imaging multiple optical contrasts, which is not typically offered by a single imaging modality. Different optical imaging modalities providing absorption, scattering and molecular information of biological tissues, have been developed and used in many biomedical investigations in the past decades. Large field-of-view (FOV) and high imaging speed are desired for all these imaging techniques. Uneven surface of a sample can lead to uneven depth focus, resulting in images with non-uniform resolution and signal intensity especially in large FOV imaging. Here, we report on our newly developed OCT-guided opto-mechanical scanning multimodal imaging system with the capability of dynamic focusing. By taking advantage of the depth resolving capability of OCT, we developed a novel OCT-guided surface contour scanning methodology for dynamic focusing during entire scanning of an uneven sample. To achieve this, we combined a fully motorized three-dimensional mechanical stage with an X-Y galvanometer optical scanner which made the imaging system suitable for fast scanning of large area. This imaging system integrates photoacoustic microscopy (PAM), optical coherence tomography (OCT) and fluorescence microscopy in one platform providing absorption, structural and molecular information of biological tissue, respectively. Phantom, ex vivo, and in vivo imaging studies demonstrated the performance of the OCT-guided surface contour scanning scheme as well as the capability of our multimodal imaging system to provide comprehensive microscopic information on biological tissues with large FOV and fast scanning. We believe this novel multimodal imaging system has promising potential for preclinical research and clinical practice in the near future. \u0000\u0000\u0000Keywords: Multimodal optical imaging, optical microscopy, photoacoustic microscopy, optical coherence tomography, fluorescence microscopy, dynamic focusing","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"405 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115920536","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}

{"title":"Sensing ultrasound optically with photonic crystal slabs: a tale of two mechanisms (Conference Presentation)","authors":"E. Zhu, C. Rewcastle, R. Gad, L. Qian, O. Levi","doi":"10.1117/12.2508998","DOIUrl":"https://doi.org/10.1117/12.2508998","url":null,"abstract":"Silicon Photonics-based sensors can provide low cost, high sensitivity optical detection solutions in ultrasound and photoacoustic (PA) imaging. We demonstrate experimentally the measurement of ultrasound (2.5-8.5 MHz) in water using photonic crystal slab (PCS) nanostructure devices. Each PCS is composed of a periodic array of nanoholes, etched into silicon nitride (t=160 nm), on top of a silicon dioxide layer, and silicon substrate. The PCS devices have guided resonances that peak at ~ 1550 nm, with linewidths that vary from 0.7 to 5.5 nm. \u0000\u0000One type of PCS device includes a PCS nanostructure located above a thin micro-fabricated silicon membrane (~ 10 micron thick). Membrane deformation by incoming ultrasound waves induce resonance changes in the PCS spectral peak location (i.e., drum effect). We observe these drum-effect PCS devices to have acoustic sensitivities that are very narrowband (with bandwidths ~ 1 MHz), with a 300-micron diameter drum device found to have a peak sensitivity at 5 MHz and a noise equivalent pressure (NEP) of 2.0 kPa (72 Pa/rt Hz). \u0000\u0000In another mechanism, the sensitivity of the PCS nanostructures to changes in the ambient index of refraction is used. A pressure wave in water that impinges the PCS is accompanied by changes in the water's index of refraction, which causes the resonance peak of the PCS to shift. The acoustic sensitivities of these PCS devices is found to be broadband (> 6 MHz), in contrast to the drum-effect devices, with an NEP of less than 0.5 kPa (6.7 Pa/rt Hz). These devices can potentially allow for optics-based monolithic ultrasound sensor arrays, optimized for PA imaging.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131545347","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}

{"title":"Exploiting blood flow fluctuations to improve visibility in photoacoustic imaging (Conference Presentation)","authors":"Sergey Vilov, B. Arnal, E. Bossy","doi":"10.1117/12.2507447","DOIUrl":"https://doi.org/10.1117/12.2507447","url":null,"abstract":"","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133696217","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}

{"title":"International Photoacoustic Standardisation Consortium (IPASC): overview (Conference Presentation)","authors":"S. Bohndiek, J. Brunker, J. Gröhl, Lina Hacker, J. Joseph, W. Vogt, P. Armanetti, H. Assi, J. Bamber, P. Beard, T. Berer, R. Bouchard, K. Briggman, L. Cavigli, Bryan Clingman, B. Cox, A. Desjardins, A. Heinmiller, Jeesong Hwang, E. Hysi, Aoife M. Ivory, J. Jose, T. Kirchner, J. Klohs, L. Maier-Hein, Efthymios Maneas, J. Mannheim, S. Manohar, L. McNally, L. Menichetti, Steven Miller, S. Morscher, R. Ni, Yoko Okamura, M. Olivo, M. Pagel, G. Parker, A. Pelagotti, A. Pifferi, S. Rajagopal, F. Ratto, D. Razansky, L. Richards, A. Ron, M. K. Singh, M. Waldner, Kun Wang, Lihong V. Wang, W. Xia, B. Zeqiri","doi":"10.1117/12.2506044","DOIUrl":"https://doi.org/10.1117/12.2506044","url":null,"abstract":"The International Photoacoustic Standardisation Consortium (IPASC) emerged from SPIE 2018, established to drive consensus on photoacoustic system testing. As photoacoustic imaging (PAI) matures from research laboratories into clinical trials, it is essential to establish best-practice guidelines for photoacoustic image acquisition, analysis and reporting, and a standardised approach for technical system validation. The primary goal of the IPASC is to create widely accepted phantoms for testing preclinical and clinical PAI systems. To achieve this, the IPASC has formed five working groups (WGs). The first and second WGs have defined optical and acoustic properties, suitable materials, and configurations of photoacoustic image quality phantoms. These phantoms consist of a bulk material embedded with targets to enable quantitative assessment of image quality characteristics including resolution and sensitivity across depth. The third WG has recorded details such as illumination and detection configurations of PAI instruments available within the consortium, leading to proposals for system-specific phantom geometries. This PAI system inventory was also used by WG4 in identifying approaches to data collection and sharing. Finally, WG5 investigated means for phantom fabrication, material characterisation and PAI of phantoms. Following a pilot multi-centre phantom imaging study within the consortium, the IPASC settled on an internationally agreed set of standardised recommendations and imaging procedures. This leads to advances in: (1) quantitative comparison of PAI data acquired with different data acquisition and analysis methods; (2) provision of a publicly available reference data set for testing new algorithms; and (3) technical validation of new and existing PAI devices across multiple centres.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"2006 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132678032","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}

{"title":"Clinical evaluation of a high resolution 3D photoacoustic scanner for the assessment of peripheral vascular disease: technical feasibility and clinical utility (Conference Presentation)","authors":"N. Huynh, A. Plumb, B. Cox, E. Zhang, P. Beard","doi":"10.1117/12.2508498","DOIUrl":"https://doi.org/10.1117/12.2508498","url":null,"abstract":"Photoacoustic imaging instruments based on the Fabry Perot ultrasound sensing concept have been used extensively for the preclinical assessment of mouse models and shown to provide high fidelity images to sub-cm depths. In a new development, a 3D high resolution scanner based on the same technology has now been specifically engineered into a format comprising a mobile platform and a convenient hand-held imaging probe for clinical use. A number of key engineering developments designed to advance the clinical translation of the technology have been implemented. The system now employs a novel 32-channel optical scanning architecture and a 1kHz PRF excitation laser providing an order-of-magnitude faster acquisition than previous pre-clinical embodiments. 3D images can now be acquired within 1 second, and video rate 2D synthetic aperture imaging is achievable. Image acquisition speed can be further accelerated by employing sub-sampling techniques based on total variation and deep learning image reconstruction, e.g. 3D images can be obtained at the rate of 4Hz with a typical 25% sub-sampling factor. To further aid clinical utility, the scanner allows rapid switching between the two imaging modes. This enables the ROI to be searched for and located in real-time using the 2D video rate mode prior to 3D image acquisition. Additional recent technical developments include bias wavelength tracking for temperature compensation, synthetic 1.5D array based receive beam forming for out-of-plane signal rejection, fast image reconstruction and visualisation and the implementation of an intuitive user-friendly interface.\u0000\u0000To confirm clinical applicability, proof-of-concept studies both in healthy volunteers and patients have been conducted using the system. Following ethical and local regulatory approval, consenting patients were recruited from a single tertiary care hospital. Participants had previously been diagnosed with peripheral vascular disease (PVD), head and neck malignant tumours (including nodal deposits), inflammatory arthritis, or were under active clinical investigation for these conditions. We obtained mutliwavelength 3D images of the superficial vasculature in critically-ischaemic and normally perfused regions in patients with PVD. In both cases, the photoacoustic images were compared to clinical B-mode and Doppler ultrasound scans. The results show that the scanner is able to visualise the spatial-temporal changes in human microvasculature and thus may be able to identify regions of ischaemia otherwise undetectable using existing modalities. Images of small joint arthopathies, and malignant lymph nodes were also obtained, and compared with contemporaneous high resolution ultrasound. Patients found the use of the scanner highly acceptable, both in degree of comfort and the duration of the scan procedure. This exploratory phase clinical study represents an initial step towards establishing the clinical utility of photoacoustic imaging in a range of c","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131275815","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}

{"title":"Integrated photoacoustic microscopy, optical coherence tomography and fluorescence microscopy imaging of rabbit retinal neovascularization in vivo (Conference Presentation)","authors":"Wei Zhang, Yanxiu Li, V. Nguyen, Zhipeng Liu, Xueding Wang, Y. Paulus","doi":"10.1117/12.2508115","DOIUrl":"https://doi.org/10.1117/12.2508115","url":null,"abstract":"Retinal neovascularization is a major cause of vision loss and blindness, and is a common complication of numerous retinal diseases, including proliferative diabetic retinopathy, retinopathy of prematurity, sickle cell retinopathy, and retinal vein occlusions. Early diagnosis can be highly beneficial to the treatment of angiogenesis-related eye diseases. Due the limitations of current ocular imaging methods, a hybrid imaging approach that can combine the advantages of current imaging technologies with additional functional and molecular information is highly desired in the field of ophthalmology. A multimodality imaging system with integrated optical coherence tomography (OCT), photoacoustic microscopy (PAM), and fluorescence microscopy (FM) has been developed to evaluate the angiogenesis in clinically relevant larger animal eyes. Real-time, high resolution in vivo imaging was performed in live rabbit eyes with vascular endothelial growth factor (VEGF)-induced retinal neovascularization. PAM images demonstrate a network of tortuous neovascularization on the retina peaking at 7 days post-injection. Blood vessels and irregular vascular structures can also be indicated by OCT B-mode imaging. Leakage of retinal neovascularization is demonstrated by fluorescein sodium with FM. Quantitative analysis of retinal neovascularization has been achieved by PAM. The experimental results demonstrate that this multimodality imaging system can noninvasively visualize retinal neovascularization in both albino and pigmented rabbits for characterization of retinal pathology. This work presents the first description of a multimodality PAM, OCT, and FM system for high resolution, real-time visualization of angiogenesis in rabbits, and could be an important step toward the clinical translation of the technology.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115044754","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}

{"title":"Speckle formation in acoustic-resolution photoacoustic imaging (Conference Presentation)","authors":"E. Hysi, Muhannad N Fadhel, M. Moore, Tae-Hoon Bok, J. Zalev, E. Strohm, Michael C. Kolios","doi":"10.1117/12.2508837","DOIUrl":"https://doi.org/10.1117/12.2508837","url":null,"abstract":"In this work, speckle in acoustic-resolution photoacoustic (PA) imaging systems is discussed. Simulations and experiments were used to demonstrate that PA speckle carries structural information related to sub-resolution absorbers. \u0000\u0000Numerical simulations of phantoms containing spherical absorbers were performed using Green’s function solutions to the PA wave equation. A 21 MHz linear array was simulated (256 elements, 75×165 µm resolution, bandwidth 9-33 MHz) and used to record, bandlimit and beamform the generated PA signals. The effects of absorber size (10-270 µm) and concentration (10-1000/mm3) on PA speckle were examined using envelope statistics and radiofrequency spectroscopy techniques. To examine PA speckle experimentally, a VevoLAZR system was used to image gelatin phantoms containing 3 and 15µm polystyrene beads, a tissue mimicking radial artery phantom, and murine tumour vasculature in vivo.\u0000\u0000Fully developed speckle, as assessed by Rayleigh distribution fits to PA signal envelopes, was present in all images (simulated and experimental) containing at least 10 absorbers per resolution volume, irrespective of absorber size. Changes in absorber size could be detected using the spectral slope of the normalized power spectrum (4.5x decrease for an 80 µm increase in size). PA images of flowing blood in the radial artery phantom also revealed the presence of speckle with intensity that fluctuated periodically with beat rate (4 dB per cycle). Speckle was ubiquitous to all murine tumor vasculature images. During treatment-induced vascular hemorrhaging, the spectral slope decreases by 80% compared to untreated mice. These results demonstrate that photoacoustic speckle encodes information about the underlying absorber distribution.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129435456","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}

{"title":"In vivo three dimensional cuticle intact Drosophila brain imaging using laser scanning optical resolution photoacoustic microscopy","authors":"K. Chang, Hsuan Ou-Yang, Pei-Shan Ho, Shun-Chi Wu, Yen-Yin Lin, A. Chiang, Meng-Lin Li","doi":"10.1117/12.2508091","DOIUrl":"https://doi.org/10.1117/12.2508091","url":null,"abstract":"To study the structure and functions of the Drosophila brain, confocal microscopy is commonly used. However, surgical removal of the head cuticle of Drosophila is required because the cuticle hinders both the optical excitation and detection. Such invasive surgery may affect brain functions and prohibits long term monitoring. Targeting to the unmet need of surgery free procedure, here we propose laser scanning optical resolution photoacoustic microscopy (LSOR-PAM) for in vivo three dimensional cuticle intact Drosophila brain imaging. Cuticle intact Drosophila brains with cells in optic lobes expressing fluorescent protein DsRed, which serves as an optical absorber and thus a photoacoustic signal source, were imaged. Acquired in vivo 3D LSOR-PAM cuticle-intact brain images were cross-validated using their confocal microscopic counterparts with the cuticles being surgically removed. Acoustic and optical attenuation of the cuticles and degradation in spatial resolution caused by the cuticles were also measured, which explains the reason why LSOR-PAM outperforms confocal microscopy for cuticle intact brains. In addition, the optical absorption bleaching of DsRed expressing optic lobes as a function of the number of the repeated experiments was measured, verifying the LSOR-PAM long-term monitoring capability. In summary, we have demonstrated 3D LSOR-PAM of the Drosophila brain without invasive surgery for the first time. The focus of the future work will be on ways to explore its functional imaging capability on the cuticle intact Drosophila brain.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130514386","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}