https://scholar.dgist.ac.kr/handle/20.500.11750/13550 2026-04-04T08:12:09Z https://scholar.dgist.ac.kr/handle/20.500.11750/59270 Title: Ultrasound localization microscopy lite (ULM lite): ultrasound localization microscopy with resource-efficient signal processing scheme Author(s): Seong, Hyojin; Jung, Jinhwan; Jung, Dongkyu; Guezzi, Nizar; Nam, Sangwoo; Lee, Sangheon; Noman, Muhammad; Her, Taehoon; Cho, Eungyeong; Yoon, Heechul; Lee, Taeyoung; Hyun, Jung Ho; Yu, Jaesok Abstract: Ultrasound localization microscopy (ULM) is a groundbreaking, non-invasive imaging tool for monitoring vascular hemodynamics and neuronal activities in rodent models with exceptional spatial resolution. Despite its potential, the extensive data size required by the current ULM framework poses significant limitations to its broader applications. This study addresses these challenges by introducing sub-Nyquist sampling of the bandlimited radio-frequency (RF) signals, a method designed to reduce resource demands while preserving image quality. In this study, we experimentally demonstrate the in vivo feasibility of the proposed method. Our results show that 67 % of band-limited signal images achieve a high signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), comparable to those of conventional 200 % bandwidth signals. Even under stringent data reduction conditions, the proposed approach reduces the data size by approximately one-third without compromising image quality. These results highlight the potential of the proposed approach holds significant promise for enhancing the efficiency and practicality of ULM, facilitating the non-invasive visualization of deep neuronal activities with improved resource efficiency. 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58886 Title: High-frequency (> 65 MHz) broadband transparent transducer with ultrathin gold electrode for dual-mode photoacoustic and laser-induced ultrasound microscopy Author(s): Park, Sunghun; Hong, Woongki; Park, Hyeongyu; Lee, Eunji; Nam, Sangwoo; Jung, Jin Hwan; Hyun, Jung Ho; Yu, Jaesok; Kang, Hongki; Chang, Jin Ho Abstract: For high-performance combined photoacoustic (PA) and Ultrasound (US) microscopy, precise coaxial alignment of the US and laser beams is essential. This can be realized using broadband transparent ultrasound transducers (TUTs). However, the current dual-mode imaging systems encounter significant challenges in simultaneous PA and US data acquisition due to sequential transmission of light and ultrasound and mechanical movement of dual-mode probes, leading to longer acquisition times and potential registration inaccuracies. To overcome these limitations, we propose a recently developed high-frequency broadband TUT with an ultrathin (< 10 nm) gold electrode, achieving a center frequency of 65.6 MHz and a –6 dB bandwidth of 71.6 %. The ultrathin gold electrode facilitates laser-induced ultrasound (LUS), enabling simultaneous acquisition of PA and US images. In vivo experiments demonstrate that LUS imaging can effectively replace conventional US imaging, offering highly efficient dual-mode PA/US imaging with minimized registration errors. 2025-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58221 Title: Engram and behavior: How memory is stored in the brain Author(s): Eom, Kisang; Kim, Donguk; Hyun, Jung Ho Abstract: During the processing of information in humans, activated neurons behave in a specific way. The activity of these neurons leaves traces on the neurons, such as changes in synaptic or intrinsic properties. Formation of the memory traces is associated with molecular changes in the neurons. Hence, monitoring collective neural activities and following the trace of neural activities are important to neuroscience research. This collective or group of neurons is described as a &apos;neural ensemble&apos;, while the neural trace is described as a &apos;neural engram&apos;. Both terms have been used and studied by neuroscientists for a long time. In this article, we discuss the development of these concepts, current research methods, and future areas of development. 2025-04-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/56892 Title: Molecular tools for recording and intervention of neuronal activity Author(s): Eom, Kisang; Jung, Jin Hwan; Kim, Byungsoo; Hyun, Jung Ho Abstract: Observing the activity of neural networks is critical for the identification of learning and memory processes, as well as abnormal activities of neural circuits in disease, particularly for the purpose of tracking disease progression. Methodologies for describing the activity history of neural networks using molecular biology techniques first utilized genes expressed by active neurons, followed by the application of recently developed techniques including optogenetics and incorporation of insights garnered from other disciplines, including chemistry and physics. In this review, we will discuss ways in which molecular biological techniques used to describe the activity of neural networks have evolved along with the potential for future development. © 2024 The Author(s) 2024-03-31T15:00:00Z