Browsing by Author "Zhang, Fan"

Now showing 1 - 4 of 4
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    Low-Cost High-Resolution Microendoscopy for the Detection of Esophageal Squamous Cell Neoplasia: An International Trial
    (Elsevier, 2015) Protano, Marion-Anna; Xu, Hong; Wang, Guiqi; Polydorides, Alexandros D.; Dawsey, Sanford M.; Cui, Junsheng; Xue, Liyan; Zhang, Fan; Quang, Timothy; Pierce, Mark C.; Shin, Dongsuk; Schwarz, Richard A.; Bhutani, Manoop S.; Lee, Michelle; Parikh, Neil; Hur, Chin; Xu, Weiran; Moshier, Erin; Godbold, James; Mitcham, Josephine; Hudson, Courtney; Richards-Kortum, Rebecca R.; Anandasabapathy, Sharmila; Bioengineering
    Background & Aims: Esophageal squamous cell neoplasia has a high mortality rate as a result of late detection. In high-risk regions such as China, screening is performed by Lugol’s chromoendoscopy (LCE). LCE has low specificity, resulting in unnecessary tissue biopsy with a subsequent increase in procedure cost and risk. The purpose of this study was to evaluate the accuracy of a novel, low-cost, high-resolution microendoscope (HRME) as an adjunct to LCE. Methods: In this prospective trial, 147 consecutive high-risk patients were enrolled from 2 US and 2 Chinese tertiary centers. Three expert and 4 novice endoscopists performed white-light endoscopy followed by LCE and HRME. All optical images were compared with the gold standard of histopathology. Results: By using a per-biopsy analysis, the sensitivity of LCE vs LCE + HRME was 96% vs 91% (P = .0832), specificity was 48% vs 88% (P < .001), positive predictive value was 22% vs 45% (P < .0001), negative predictive value was 98% vs 98% (P = .3551), and overall accuracy was 57% vs 90% (P < .001), respectively. By using a per-patient analysis, the sensitivity of LCE vs LCE + HRME was 100% vs 95% (P = .16), specificity was 29% vs 79% (P < .001), positive predictive value was 32% vs 60%, 100% vs 98%, and accuracy was 47% vs 83% (P < .001). With the use of HRME, 136 biopsies (60%; 95% confidence interval, 53%–66%) could have been spared, and 55 patients (48%; 95% confidence interval, 38%–57%) could have been spared any biopsy. Conclusions: In this trial, HRME improved the accuracy of LCE for esophageal squamous cell neoplasia screening and surveillance. HRME may be a cost-effective optical biopsy adjunct to LCE, potentially reducing unnecessary biopsies and facilitating real-time decision making in globally underserved regions. ClinicalTrials.gov, NCT 01384708.
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    Quantitative Analysis of High-Resolution Microendoscopic Images for Diagnosis of Esophageal Squamous Cell Carcinomaﾠ
    (Elsevier, 2015) Shin, Dongsuk; Protano, Marion-Anna; Polydorides, Alexandros D.; Dawsey, Sanford M.; Pierce, Mark C.; Kim, Michelle Kang; Schwarz, Richard A.; Quang, Timothy; Parikh, Neil; Bhutani, Manoop S.; Zhang, Fan; Wang, Guiqi; Xue, Liyan; Wang, Xueshan; Xu, Hong; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca R.; Bioengineering
    Background & Aims: High-resolution microendoscopy is an optical imaging technique with the potential to improve the accuracy of endoscopic screening for esophageal squamous neoplasia. Although these microscopic images can be interpreted readily by trained personnel, quantitative image analysis software could facilitate the use of this technology in low-resource settings. In this study, we developed and evaluated quantitative image analysis criteria for the evaluation of neoplastic and non-neoplastic squamous esophageal mucosa. Methods: We performed an image analysis of 177 patients undergoing standard upper endoscopy for screening or surveillance of esophageal squamous neoplasia, using high-resolution microendoscopy, at 2 hospitals in China and at 1 hospital in the United States from May 2010 to October 2012. Biopsy specimens were collected from imaged sites (n = 375), and a consensus diagnosis was provided by 2 expert gastrointestinal pathologists and used as the standard. Results: Quantitative information from the high-resolution images was used to develop an algorithm to identify high-grade squamous dysplasia or invasive squamous cell cancer, based on histopathology findings. Optimal performance was obtained using the mean nuclear area as the basis for classification, resulting in sensitivities and specificities of 93% and 92% in the training set, 87% and 97% in the test set, and 84% and 95% in an independent validation set, respectively. Conclusions: High-resolution microendoscopy with quantitative image analysis can aid in the identification of esophageal squamous neoplasia. Use of software-based image guides may overcome issues of training and expertise in low-resource settings, allowing for widespread use of these optical biopsy technologies.
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    Room-Temperature Topological Phase Transition in Quasi-One-Dimensional Material Bi4I4
    (American Physical Society, 2021) Huang, Jianwei; Li, Sheng; Yoon, Chiho; Oh, Ji Seop; Wu, Han; Liu, Xiaoyuan; Dhale, Nikhil; Zhou, Yan-Feng; Guo, Yucheng; Zhang, Yichen; Hashimoto, Makoto; Lu, Donghui; Denlinger, Jonathan; Wang, Xiqu; Lau, Chun Ning; Birgeneau, Robert J.; Zhang, Fan; Lv, Bing; Yi, Ming
    Quasi-one-dimensional (1D) materials provide a superior platform for characterizing and tuning topological phases for two reasons: (i) existence for multiple cleavable surfaces that enables better experimental identification of topological classification and (ii) stronger response to perturbations such as strain for tuning topological phases compared to higher dimensional crystal structures. In this paper, we present experimental evidence for a room-temperature topological phase transition in the quasi-1D material Bi4I4, mediated via a first-order structural transition between two distinct stacking orders of the weakly coupled chains. Using high-resolution angle-resolved photoemission spectroscopy on the two natural cleavable surfaces, we identify the high-temperature β phase to be the first weak topological insulator with two gapless Dirac cones on the (100) surface and no Dirac crossing on the (001) surface, while in the low-temperature α phase, the topological surface state on the (100) surface opens a gap, consistent with a recent theoretical prediction of a higher-order topological insulator beyond the scope of the established topological materials databases that hosts gapless hinge states. Our results not only identify a rare topological phase transition between first-order and second-order topological insulators but also establish a novel quasi-1D material platform for exploring unprecedented physics.
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    Three-dimensional mesostructures as high-temperature growth templates, electronic cellular scaffolds, and self-propelled microrobots
    (National Academy of Sciences, 2017) Yan, Zheng; Han, Mengdi; Shi, Yan; Badea, Adina; Yang, Yiyuan; Kulkarni, Ashish; Hanson, Erik; Kandel, Mikhail E.; Wen, Xiewen; Zhang, Fan; Luo, Yiyue; Lin, Qing; Zhang, Hang; Guo, Xiaogang; Huang, Yuming; Nan, Kewang; Jia, Shuai; Oraham, Aaron W.; Mevis, Molly B.; Lim, Jaeman; Guo, Xuelin; Gao, Mingye; Ryu, Woomi; Yu, Ki Jun; Nicolau, Bruno G.; Petronico, Aaron; Rubakhin, Stanislav S.; Lou, Jun; Ajayan, Pulickel M.; Thornton, Katsuyo; Popescu, Gabriel; Fang, Daining; Sweedler, Jonathan V.; Braun, Paul V.; Zhang, Haixia; Nuzzo, Ralph G.; Huang, Yonggang; Zhang, Yihui; Rogers, John A.
    Exploiting advanced 3D designs in micro/nanomanufacturing inspires potential applications in various fields including biomedical engineering, metamaterials, electronics, electromechanical components, and many others. The results presented here provide enabling concepts in an area of broad, current interest to the materials community––strategies for forming sophisticated 3D micro/nanostructures and means for using them in guiding the growth of synthetic materials and biological systems. These ideas offer qualitatively differentiated capabilities compared with those available from more traditional methodologies in 3D printing, multiphoton lithography, and stress-induced bending––the result enables access to both active and passive 3D mesostructures in state-of-the-art materials, as freestanding systems or integrated with nearly any type of supporting substrate.