{"title":"Congenital coarctation of the aorta: Role of peripheral vascular ultrasound in young hypertensive patients.","authors":"Wen Zhou, Shunji Gao, Rui Du, Huijuan Xiang, Yuejuan Gao, Wenhong Gao","doi":"10.1055/a-2436-1007","DOIUrl":"https://doi.org/10.1055/a-2436-1007","url":null,"abstract":"","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a24361007"},"PeriodicalIF":1.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11533725/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142576990","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}
Silvia Mongodi, Davide Chiumello, Francesco Mojoli
{"title":"Lung ultrasound score for the assessment of lung aeration in ARDS patients: comparison of two approaches.","authors":"Silvia Mongodi, Davide Chiumello, Francesco Mojoli","doi":"10.1055/a-2421-8709","DOIUrl":"https://doi.org/10.1055/a-2421-8709","url":null,"abstract":"<p><p><b>Purpose</b> A 4-step lung ultrasound (LUS) score has been previously used to quantify lung density. We compared 2 versions of this scoring system for distinguishing severe from moderate loss of aeration in ARDS: coalescence-based score (cLUS) vs. quantitative-based score (qLUS - >50% pleura occupied by artefacts). <b>Materials and Methods</b> We compared qLUS and cLUS to lung density measured by quantitative CT scan in 12 standard thoracic regions. A simplified approach (1 scan per region) was compared to an extensive one (regional score computed as the mean of all relevant intercostal space scores). <b>Results</b> We examined 13 conditions in 7 ARDS patients (7 at PEEP 5, 6 at PEEP 15 cmH2O-156 regions, 398 clips). Switching from cLUS to qLUS resulted in a change in interpretation in 117 clips (29.4%, 1-point reduction) and in 41.7% of the regions (64 decreases (range 0.2-1), 1 increase (0.2 points)). Regional qLUS showed very strong correlation with lung density (rs=0.85), higher than cLUS (rs=0.79; p=0.010). The agreement with CT classification in well aerated, poorly aerated, and not aerated tissue was moderate for cLUS (agreement 65.4%; Cohen's K coefficient 0.475 (95%CI 0.391-0.547); p<0.0001) and substantial for qLUS (agreement 81.4%; Cohen's K coefficient 0.701 (95%CI 0.653-0.765), p<0.0001). The agreement between single spot and extensive approaches was almost perfect (cLUS: agreement 89.1%, Cohen's kappa coefficient 0.840 (95%CI 0.811-0.911), p<0.0001; qLUS: agreement 86.5%, Cohen's kappa coefficient 0.819 (95%CI 0.761-0.848), p<0.0001). <b>Conclusion</b> A LUS score based on the percentage of occupied pleura performs better than a coalescence-based approach for quantifying lung density. A simplified approach performs as well as an extensive one.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a24218709"},"PeriodicalIF":1.3,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11497101/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142510027","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}
Jennifer Meier, Claudia Lucius, Kathleen Möller, Christian Jenssen, Constantinos Zervides, Anna Maria Gschmack, Yi Dong, David Srivastava, Christoph F Dietrich
{"title":"Pancreatic ultrasound: An update of measurements, reference values, and variations of the pancreas.","authors":"Jennifer Meier, Claudia Lucius, Kathleen Möller, Christian Jenssen, Constantinos Zervides, Anna Maria Gschmack, Yi Dong, David Srivastava, Christoph F Dietrich","doi":"10.1055/a-2389-9085","DOIUrl":"https://doi.org/10.1055/a-2389-9085","url":null,"abstract":"<p><p>Reliable and reproducible measurement methods have been established, and reference values are used in almost all scientific disciplines. Knowledge of reference values is crucial to distinguish physiological from pathological processes and, therefore, subsequently, for the clinical management of patients. Image storage and documentation of measurements and normal findings should be part of quality assurance in imaging. This paper aims to review the published literature and provide current knowledge of sonographic measurements and reference values of the pancreas. Moreover, the role of clinical influencing factors such as age, gender, constitution, and ethnicity is also analyzed.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a23899085"},"PeriodicalIF":1.3,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11475099/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142477175","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}
Christoph F Dietrich, Yi Dong, Xin-Wu Cui, Mathias Fink, Christian Jenssen, Kathleen Moeller, Laurent Sandrin, Sugimoto Tsuneyoshi, Mickael Tanter
{"title":"Ultrasound elastography: a brief clinical history of an evolving technique.","authors":"Christoph F Dietrich, Yi Dong, Xin-Wu Cui, Mathias Fink, Christian Jenssen, Kathleen Moeller, Laurent Sandrin, Sugimoto Tsuneyoshi, Mickael Tanter","doi":"10.1055/a-2378-6926","DOIUrl":"https://doi.org/10.1055/a-2378-6926","url":null,"abstract":"<p><p>The history of the emerging elastographic technique is presented. Ultrasound imaging of elasticity and tissue strain has gained clinical acceptance as an established technique useful in routine daily clinical practice.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a23786926"},"PeriodicalIF":1.3,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11472523/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142477177","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}
Johannes M Weimer, Florian Recker, Leonie Horn, Julian Kuenzel, Klaus Dirks, Carlotta Ille, Holger Buggenhagen, Norbert Börner, Andreas Michael Weimer, Thomas Vieth, Liv Lorenz, Maximilian Rink, Daniel Merkel, Anna Dionysopoulou, Michael Ludwig, Roman Kloeckner, Julia Weinmann-Menke, Lukas Müller
{"title":"Insights Into Modern Undergraduate Ultrasound Education: Prospective Comparison of Digital and Analog Teaching Resources in a Flipped Classroom Concept - The DIvAN Study.","authors":"Johannes M Weimer, Florian Recker, Leonie Horn, Julian Kuenzel, Klaus Dirks, Carlotta Ille, Holger Buggenhagen, Norbert Börner, Andreas Michael Weimer, Thomas Vieth, Liv Lorenz, Maximilian Rink, Daniel Merkel, Anna Dionysopoulou, Michael Ludwig, Roman Kloeckner, Julia Weinmann-Menke, Lukas Müller","doi":"10.1055/a-2389-9410","DOIUrl":"https://doi.org/10.1055/a-2389-9410","url":null,"abstract":"<p><p><b>Purpose</b> Sonography training has become an important part of university medicine courses. This study explores the impact of digital and analog teaching resources on learning outcomes, knowledge retention, and student preferences and motivation in a flipped classroom setting. <b>Materials and Methods</b> This prospective controlled study involving two groups of third-year medical students included a voluntary three-day compact ultrasound course given in a flipped classroom, comprising 26 teaching units of 45 minutes each. Hardcopy lecture notes (control group) and E-learning (study group) were used as teaching resources. Evaluations were conducted before (pre) and during the preparation phase (intermediate), and after (post) the face-to-face course. Likert scale responses, written theory tests with very short answer questions (Theorypre, Theoryinter, Theorypost), and practical examinations (Practiceinter, Practicepost) were used for student self-assessment and to measure attitude, motivation, as well as theoretical and practical skills. <b>Results</b> A total of N=236 complete data sets (study group n=136; control group n=100) were analyzed. Both groups showed an equivalent initial level of, and a continuous and significant (p<0.01) increase in, subjective and objective skills over the evaluated time frame. The study group achieved significantly (p<0.05) better results in Theoryinter, Theorypost, Practiceinter, and Practicepost. The study group evaluated their teaching resource and the training concept significantly (p<0.05) better. <b>Conclusion</b> The integration of digital resources into sonography education provides comparable learning outcomes to traditional analog materials, enhancing the preparatory phase. In the future, digitally supported training should be used more.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a23899410"},"PeriodicalIF":1.3,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11472524/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142477174","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}
Léna G Dietrich, Bettina Juon, Christian Wirtz, Esther Vögelin
{"title":"Ultrasonographic Evaluation of Morphological Changes in Peripheral Nerves after Traumatic Injury and Nerve Repair - A Prospective Study.","authors":"Léna G Dietrich, Bettina Juon, Christian Wirtz, Esther Vögelin","doi":"10.1055/a-2378-6902","DOIUrl":"https://doi.org/10.1055/a-2378-6902","url":null,"abstract":"<p><p><b>Purpose</b> Ultrasound (US) has gained in importance for the visualization of morphological changes of injured nerves. After surgical repair, changes in neural structures are seen over time. The correlation of morphologic changes in US with the corresponding nerve function is uncertain. The aim of this study is to determine a correlation of post-traumatic morphological nerve changes with US and with nerve function after surgery. <b>Materials and Methods</b> This dual-center, prospective cohort study was conducted between 2017 and 2022 and included 20 mixed sensory motor nerve lesions. Patients were followed up clinically (sensitivity, pain, and motor function) with US and electroneuromyography. We determined the US changes of the nerves including the interaction of the tissue after nerve repair and any correlation with nerve function. With US nerve cross-sectional area (CSA), the number of traversing fascicles, hypo-echogenicity, and presence of perineural scar were analyzed. <b>Results</b> 20 lesions (12 median and 8 ulnar nerves) of 18 patients with intraoperatively confirmed nerve injury of at least 50% in the forearm were included. The average CSA was over 20 mm <sup>2</sup> throughout the follow-up period, corresponding to a neuroma in continuity compared to the opposite side (10.75 mm <sup>2</sup> ). Sensibility and motor function at 12 months were 6xS3/4 and 10xM3-5. There was a statistically significant correlation between continuous fascicles on US at 6 months and sensitivity at 12 months. <b>Conclusion</b> This study supports the presence of post-traumatic morphological changes in nerve fibers with US after traumatic injury. Morphological changes in nerve structure after trauma can be detected with US indicating a correlation between continuity of nerve fascicles and development of sensitivity and motor function.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a23786902"},"PeriodicalIF":1.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11472627/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142477176","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}
Ying Tan, Huaxuan Wen, Guiyan Peng, Huiying Wen, Xin Wen, Yao Jiang, Jiaqi Fan, Ying Yuan, Dandan Luo, Shengli Li
{"title":"Introducing and Validating the Cranial-Dorsal-Hip Angle (∠CDH): A Method for Accurate Fetal Position Assessment in the First Trimester and Future AI Applications.","authors":"Ying Tan, Huaxuan Wen, Guiyan Peng, Huiying Wen, Xin Wen, Yao Jiang, Jiaqi Fan, Ying Yuan, Dandan Luo, Shengli Li","doi":"10.1055/a-2337-0078","DOIUrl":"https://doi.org/10.1055/a-2337-0078","url":null,"abstract":"<p><p><b>Purpose</b> To introduce the cranial-dorsal-hip angle (∠CDH) as a novel quantitative tool for assessing fetal position in the first trimester and to validate its feasibility for future AI applications. <b>Materials and Methods </b> 2520 first-trimester fetal NT exams with 2582 CRL images (January-August 2022) were analyzed at a tertiary hospital as the pilot group. Additionally, 1418 cases with 1450 fetal CRL images (September-December 2022) were examined for validation. Three expert sonographers defined a standard for fetal positions. ∠CDH measurements, conducted by two ultrasound technicians, were validated for consistency using Bland-Altman plots and the intra-class correlation coefficient (ICC). This method allowed for categorizing fetal positions as hyperflexion, neutral, and hyperextension based on ∠CDH. Comparative accuracy was assessed against Ioannou, Wanyonyi, and Roux methods using the weighted Kappa coefficient (k value). <b>Results </b> The pilot group comprised 2186 fetal CRL images, and the validation group included 1193 images. Measurement consistency was high (ICCs of 0.993; P<0.001). The established 95% reference range for ∠CDH in the neutral fetal position was 118.3° to 137.8°. The ∠CDH method demonstrated superior accuracy over the Ioannou, Wanyonyi, and Roux methods in both groups, with accuracy rates of 94.5% (k values: 0.874, 95%CI: 0.852-0.896) in the pilot group, and 92.6% (k values: 0.838, 95%CI: 0.806-0.871) in the validation group. <b>Conclusion</b> The ∠CDH method has been validated as a highly reproducible and accurate technique for first-trimester fetal position assessment. This sets the stage for its potential future integration into intelligent assessment models.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a23370078"},"PeriodicalIF":1.3,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11208982/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141471472","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":"Contrast-enhanced ultrasound features of hepatic angiomyolipoma: comparison with AFP-negative and non-viral hepatocellular carcinoma.","authors":"Yafang Zhang, Zhi-Xing Guo, Ying Liao, Yiwen Yu, Ruohan Guo, Xu Han, Lilong Lan, Jianhua Zhou","doi":"10.1055/a-2318-6654","DOIUrl":"https://doi.org/10.1055/a-2318-6654","url":null,"abstract":"<p><p><b>Purpose</b> This study aimed to compare contrast-enhanced ultrasound (CEUS) features of hepatic angiomyolipoma (HAML) and challenging cases of HCC, mainly those with no hepatitis infection but also with a low level of AFP (non-viral AFP- HCC). <b>Materials and Methods</b> The study included pathologically confirmed HAMLs and non-viral AFP- HCCs undergoing CEUS from 2012 to 2023. Sonovue (SV) CEUS and Sonazoid (SZ) CEUS characteristics of the two groups were compared. <b>Results</b> The study included 50 HAMLs (24% on SZ-CEUS) and 88 non-viral AFP- HCCs (21.6% on SZ-CEUS). The CEUS characteristics on SZ-CEUS were similar to those on SV-CEUS to a certain extent. HAMLs more frequently displayed no washout and partial washout with partial no washout, so-called PWNW, in the late phase and post-vascular phase, whereas HCCs more commonly exhibited mild washout. In the post-vascular phase, all non-viral AFP- HCCs exhibited washout, thereby facilitating differentiation from no-washoutHAMLs, superior to SV-CEUS, where some non-viral AFP- HCCs still exhibited no washout in late phase that could not be distinguished from HAMLs. It is noteworthy that PWNW was exclusively found in nodules exhibiting hyper- and hypoechoic separation of the nodules, and hyper- and hypoechoic separation of HAMLs in the post-vascular phase on SZ-CEUS demonstrated PWNW more frequently compared to the late phase, which can potentially help distinguish nodules with hyper- and hypoechoic separation as either HAML or non-viral AFP- HCC. Conclusion: This study highlighted the usefulness of SV- and SZ-CEUS for distinguishing HAML and non-viral AFP- HCC and filled in existing gaps regarding the SZ-CEUS features of HAML.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a23186654"},"PeriodicalIF":1.3,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11476071/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142477172","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}
Ricarda Neubauer, Claus Juergen Bauer, Christoph F Dietrich, Brigitte Strizek, Valentin Sebastian Schäfer, Florian Recker
{"title":"Evidence-based Ultrasound Education? - A Systematic Literature Review of Undergraduate Ultrasound Training Studies.","authors":"Ricarda Neubauer, Claus Juergen Bauer, Christoph F Dietrich, Brigitte Strizek, Valentin Sebastian Schäfer, Florian Recker","doi":"10.1055/a-2275-0702","DOIUrl":"https://doi.org/10.1055/a-2275-0702","url":null,"abstract":"<p><p>Despite a large number of studies previously conducted on educational concepts of ultrasound teaching in medical school, various controversial issues remain. Currently, recommendations for ultrasound curricula that aim to standardize ultrasound teaching are frequently based on expert panel advice instead of relying on valid evidence-based literature. In December 2022, a systematic literature review on the subject of undergraduate ultrasound education was conducted. All ultrasound studies listed in the PubMed and Google Scholar medical databases were filtered and analyzed with respect to various aspects of their methodological conduct and curricular implementation. A total of 259 publications were considered in the data synthesis, including 145 teaching studies in the field of undergraduate ultrasound education. The latter encompassed 58 (40%) studies that did not compare their ultrasound training to a control group. Furthermore, 84 (58%) of these studies did not assess knowledge prior to the applied ultrasound training, neglecting this factor's potential influence on study outcomes. Despite a great interest in the development and further implementation of ultrasound education during medical school, this process is still compromised by significant deficiencies in studies that have been conducted in the past. In order to provide a valid basis for curricular decisions, teaching studies should fulfill essential methodological requirements despite the multifactorial framework in which they are conducted. In the future, a guide for the design of ultrasound studies could be a useful aid for ultrasound enthusiasts and promote scientific knowledge gain.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a22750702"},"PeriodicalIF":1.3,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11472525/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142477173","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}
Claudio Baracchini, Elsa Azevedo, Uwe Walter, João Sargento-Freitas, Branko Malojcic
{"title":"Neurosonology Survey in Europe and Beyond.","authors":"Claudio Baracchini, Elsa Azevedo, Uwe Walter, João Sargento-Freitas, Branko Malojcic","doi":"10.1055/a-2243-9625","DOIUrl":"10.1055/a-2243-9625","url":null,"abstract":"<p><p><b>Purpose</b> To provide an overview on education, training, practice requirements, and fields of application of neurosonology in Europe and beyond. <b>Materials and Methods</b> National representatives and experts in neurosonology were surveyed regarding neurosonology requirements and practice in their countries. Descriptive statistics were used to report the data. <b>Results</b> Between February 1 and March 31, 2023, 42/46 (91.3%) national representatives responded to our questionnaire and the completion rate was 100%. Most countries (71.4%) offer a neurosonology training program during neurology residency, but it is part of the undergraduate medical program only in 30.9%. National certification is available in 47.6% of the countries surveyed and most countries (76.2%) require certification to practice. In 50% of the countries, candidates are assessed by a board examination, while in 26.2% they just need to document their practice. There is no formal accreditation of neurosonology centers in 78.6% of the countries surveyed. Only a few require certified personnel and appropriate equipment. Adequate teaching and research activities are only rarely necessary elements for laboratory accreditation. <b>Conclusion</b> Our results indicate that there is a substantial need for transnational harmonization of neurosonological standards to guarantee uniformity and quality of performance. This survey will also provide guidance to promote an international accrediting council and create a quality-controlled laboratory network for implementing neurosonology in clinical trials.</p>","PeriodicalId":44852,"journal":{"name":"Ultrasound International Open","volume":"10 ","pages":"a22439625"},"PeriodicalIF":3.2,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10921371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140094790","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}