Postdoctoral Associates

Daniel Armendariz is a postdoctoral fellow with the Ya-Chi Ho lab in the Department of Microbial Pathogenesis and a recipient of the YCCI Multidisciplinary Postdoctoral Training Program in Translational Research TL1 award. Daniel obtained his Ph.D. in Genetics, Development, and Disease at UT Southwestern under the mentorship of Dr. Gary Hon. Daniel's interests in the changing regulatory landscape of development led to his doctoral thesis, titled "CHD-associated enhancers shape human cardiomyocyte lineage commitment," which was published in eLife (2023). After a brief foray into industry working on single-cell assays, Daniel returned to academia to further his passion for cell state transitions. As a member of the Ho lab, Daniel pursues the complexities of the aging immune system, elucidating the genetic impact of age and its potential for rejuvenation.

Frank Duan is a postgraduate associate in the Department of Microbial Pathogenesis at Yale School of Medicine. He received his bachelor’s degree from UCLA, where he conducted research in Dr. Huiying Li’s lab on microbial competition among Cutibacterium species. He earned his master’s degree from Johns Hopkins University under the mentorship of Dr. Jotham Suez, focusing on the effects of antiretroviral therapy on the gut microbiome and virome. Frank joined the Pi Lab in August 2024 and is currently investigating RNA-binding proteins in Bacillus anthracis.

Bioinformatician, multi-omics in single cell and spatial.

My research focuses on how nanoscale structures drive bacterial motility and interact with host cells. In Vibrio cholerae, the pathogen that causes cholera, a single polar flagellum powers rapid swimming and contributes to infection. I am using cryo-electron microscopy to reveal the structural basis of the flagellar motor and its associated proteins, and thus the molecular mechanisms of flagellar movement. In parallel, I integrate imaging across multiple scales – from cryo-EM and cryo-electron tomography to super-resolution fluorescence and live-cell microscopy – to study dynamic nano-bio interactions in their cellular context.

Academic Background Postdoctoral Associate, Department of Microbial Pathogenesis, Yale University, (9/1/2021-present)Postgraduate Fellow, Department of Microbial Pathogenesis, Yale University (9/1/2019-3/6/2020)Joint Ph.D., Center of Cryo-Electron Microscopy, Zhejiang University (9/1/2018-6/30/2020 )Ph.D., Institute for Thermal Power Engineering, Zhejiang University (9/1/2016-6/30/2021)Exchange Student, Major in mining engineering, University of Wollongong, Australia (7/22/2015-1/22/2016) B.S. Safety Engineering, China University of Mining and Technology (9/1/2012-6/30/2016) Research Interests How the rotatory motor functionsSubcellular 3D imaging inside the cellBiosynthesis and bioengineering of microalgae cells Specialized SkillsCryo-Electron Tomography: Focused Ion Beam (FIB) milling (Aquilos 1 and 2, Thermo Fisher), cryo-correlative light and electron microscopy (Cryo-CLEM, Leica), data collection (FEI Polara, Krios, Glacios); Cryo-ET data processing, subtomogram averaging (i3, EMAN2), 3D modeling (Chimera, Amira, IMOD, EMAN2) Technology of flue gas CO2 fixation by microalgae: Microalgae culture, photobioreactor design, computational fluid dynamics (CFD) simulation (FLUENT, Ansys)

Yuanyuan Ji, PhD, is a Postdoctoral Associate at Yale School of Medicine. She earned her Ph.D. in Microbiology from China Agricultural University. At Yale, her research focuses on investigating bacterial functions using high-throughput transposon sequencing (Tn-Seq) assays and the roles of two-component systems (TCSs) in Clostridioides difficile. Outside of the lab, Yuanyuan enjoys photography and staying active through fitness.