https://dspace.ewha.ac.kr/handle/2015.oak/171694 2026-04-04T14:59:22Z 2026-04-04T14:59:22Z 주철민 https://dspace.ewha.ac.kr/handle/2015.oak/274847 2026-03-30T16:31:07Z 2026-01-01T00:00:00Z

Title: From sequence to function: Bridging single-molecule kinetics and molecular diversity Ewha Authors: 주철민 Abstract: Biological function is fundamentally determined by nucleic acid and protein sequence. Beyond encoding genetic information, nucleic acids also display complex physicochemical parameters that shape structure, dynamics, and interactions. understanding how sequence variation sculpts the energetic landscapes underlying these properties requires methods that capture both molecular diversity and dynamic behavior. Singlemolecule techniques are ideally suited to this task, but conventional formats remain time and cost intensive. recent breakthroughs have enabled highly multiplexed approaches for observing molecular dynamics across millions of individual molecules representing thousands of sequences or barcoded entities. Though still in development, these methods have begun to bridge sequence, structure, dynamics, and function at scale, opening new opportunities in drug discovery, molecular diagnostics, and functional genomics. Copyright © 2026 the authors

2026-01-01T00:00:00Z 주철민 https://dspace.ewha.ac.kr/handle/2015.oak/274825 2026-03-30T16:30:05Z 2026-01-01T00:00:00Z

Title: Single-molecule parallel analysis for rapid exploration of sequence space Ewha Authors: 주철민 Abstract: Single-molecule fluorescence techniques have been successfully applied to uncover the structure, dynamics and interactions of DNA, RNA and proteins at the molecular scale. While the structure and function of these biomolecules are imposed by their sequences, single-molecule studies have been limited to a small number of sequences due to constraints in time and cost. To gain a comprehensive understanding on how sequence influences these essential biomolecules and the processes in which they act, a vast number of sequences have to be probed, requiring a high-throughput parallel approach. To address this need, we developed SPARXS: single-molecule parallel analysis for rapid exploration of sequence space. This platform enables simultaneous profiling of millions of molecules, covering thousands of distinct sequences, at the single-molecule level by coupling single-molecule fluorescence microscopy with next-generation high-throughput sequencing. Here we describe how to implement SPARXS and give examples from our study into the effect of sequence on Holliday junction kinetics. We provide a detailed description of sample and library design, single-molecule measurement, sequencing, coupling of sequencing and single-molecule fluorescence data, and data analysis. The protocol requires experience with single-molecule fluorescence microscopy and a basic command of Python to use our Papylio package for SPARXS data analysis. Familiarity with the underlying principles of Illumina sequencing is also beneficial. The entire process takes ~1–2 weeks and provides a detailed quantitative picture of the effect of sequence on the studied process. © Springer Nature Limited 2025.

2026-01-01T00:00:00Z Aron Walsh https://dspace.ewha.ac.kr/handle/2015.oak/274768 2026-03-26T16:31:07Z 2026-01-01T00:00:00Z

Title: Spectroscopic Signatures of Structural Disorder and Electron-Phonon Interactions in Trigonal Selenium Thin Films for Solar Energy Harvesting Ewha Authors: Aron Walsh Abstract: Selenium is experiencing renewed interest as a elemental semiconductor for a range of optoelectronic and energy applications due to its irresistibly simple composition and favorable wide bandgap. However, its high volatility and low radiative efficiency make it challenging to assess structural and optoelectronic quality, calling for advanced, non-destructive characterization methods. In this work, we employ a closed-space encapsulation strategy to prevent degradation during measurement and enable sensitive probing of vibrational and optoelectronic properties. Using temperature-dependent Raman and photoluminescence spectroscopy, we investigate grown-in stress, vibrational dynamics, and electron-phonon interactions in selenium thin films synthesized under nominally identical conditions across different laboratories. Our results reveal that short-range structural disorder is not intrinsic to the material, but highly sensitive to subtle processing variations, which strongly influence electron-phonon coupling and non-radiative recombination. We find that such structural disorder and grown-in stress likely promote the formation of extended defects, which act as dominant non-radiative recombination centers limiting carrier lifetime and open-circuit voltage in photovoltaic devices. These findings demonstrate that the optoelectronic quality of selenium thin films can be significantly improved through precise control of synthesis and post-deposition treatments, outlining a clear pathway toward optimizing selenium-based thin film technologies through targeted control of crystallization dynamics and microstructural disorder. © 2026 The Author(s). Small Methods published by Wiley-VCH GmbH.

2026-01-01T00:00:00Z Andreas Heinrich https://dspace.ewha.ac.kr/handle/2015.oak/274713 2026-03-26T16:30:02Z 2025-01-01T00:00:00Z

Title: Microscopic scattering approach to in-gap states: Cr adatoms on superconducting β-Bi2Pd Ewha Authors: Andreas Heinrich Abstract: We develop a microscopic scattering formalism to describe Yu-Shiba-Rusinov (YSR) states due to a single Cr adatom on the Bi-terminated surface of beta-Bi2Pd, by combining ab initio Wannier functions with a real-space Green's function approach in the Bogoliubov-de Gennes formalism. Our framework reproduces key scanning tunneling spectroscopy features, including a single particle-hole asymmetric YSR peak and isotropic dI/dV maps around the impurity. Decomposing the YSR states reveals contributions from four nearly degenerate C4v representations, with energy broadening masking their individual signatures. Spin-orbit coupling induces partial spin polarization, while the spatial asymmetry between particle and hole components arises from Cr d-Bi p hybridization. These results highlight the importance of realistic band structures and microscopic modeling for interpreting STM data and provide a foundation for studying impurity chains hosting topological excitations.

2025-01-01T00:00:00Z