https://ir.ymlib.yonsei.ac.kr/handle/22282913/181701 Mon, 06 Jul 2026 12:47:30 GMT 2026-07-06T12:47:30Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/212744 Title: Atomic-scale evidence of Sb interdiffusion driving irreversible surface phase transition in MA3Sb2I9 lead-free perovskites Authors: Yoo, Seungwoo; Lee, Young Mi; Lee, Seungjun; Maeng, Inhee; Kim, Jae Ho; Yoshie, Yuya; Takeda, Sakura Nishino; Nakamura, Masakazu; Sun, Zhe; Oh, Seung Jae; Song, Myungkwan; Wang, Shenghao; Jung, Min-Cherl; Kwon, Young-Kyun Abstract: Cooling, rather than annealing, drives surface-to-bulk Sb interdiffusion that irreversibly reconstructs MA3Sb2I9 surfaces. In situ photoemission spectroscopy (PES) and reflection high-energy electron diffraction across the full thermal cycle show that annealing sharpens diffraction streaks and partially depletes surface methylammonium (MA), whereas cooling removes Sb-related spectral features and collapses the streaks. Density-of-states calculations including spin-orbit coupling reproduce the PES evolution, and ab initio molecular dynamics reveal the atomistic mechanism associated with Sb-deficient configurations: local Sb-I coordination collapses and covalent I-I bonds form upon Sb depletion. Treating MA depletion during annealing and Sb interdiffusion during cooling as separate steps explains the observed irreversibility and reconciles mixed reports on A3B2X9 processing. The mechanism provides practical guidance for stabilizing lead-free perovskite surfaces, including passivation before cool-down, halide-rich surface chemistries, and reduced thermal gradients. Beyond MA3Sb2I9, this cooling-aware approach offers transferable rules for processing and reliability in antimony-based, lead-free perovskites. Sat, 01 Aug 2026 00:00:00 GMT https://ir.ymlib.yonsei.ac.kr/handle/22282913/212744 2026-08-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211761 Title: A transferable SARS-CoV-2 IRES module enables dual translation initiation for enhanced antigen expression in COVID-19 mRNA vaccines Authors: Seo, Han Young; Jung, Haewon; Lee, Se-Young; Jung, Hae-Gwang; Son, Yu-Min; Bak, Yeonju; Hwang, Seo-Yeon; Kim, Jung-Hee; Park, In Ho; Shin, Jeon-Soo; Oh, Jong-Won Abstract: mRNA vaccines are a versatile platform for infectious disease prevention and therapeutic applications, yet their performance is limited by exclusive reliance on cap-dependent translation, which is markedly suppressed under hypoxia and cellular stress. Here, we report a hybrid 5 ' untranslated region (5 ' UTR) that enables dual translation initiation via both cap-dependent and internal ribosome entry site (IRES) mechanisms. This element integrates a minimal stem-loop 4.5-5 module (SL4.5-5) from the SARS-CoV-2 genomic 5 ' UTR, in which a conserved 5 '-UUUCGU-3 ' motif within the SL5 loops is essential for function. Incorporating the SL4.5-5 module downstream of conventional 5 ' UTRs confers cap-independent translation capacity and enhances overall translation efficiency under translation-restrictive conditions such as hypoxia. When applied to the 5 ' UTRs of clinically validated COVID-19 vaccines, this module improves antigen expression in both modified and unmodified mRNAs. Notably, unmodified Omicron BA.5 and XBB.1.5 mRNA vaccines containing this element elicited potent humoral and cellular immune responses at sub-microgram doses, comparable to those induced by the approved N1-methylpseu-douridine-incorporated mRNA vaccine, raxtozinameran. These findings identify SL4.5-5 as a modular IRES element that enables dual translation initiation, promoting efficient protein synthesis under cap-dependent translation-restrictive conditions and expanding the functional landscape of mRNA vaccines and therapeutics beyond cap-dependent limitations. Mon, 01 Jun 2026 00:00:00 GMT https://ir.ymlib.yonsei.ac.kr/handle/22282913/211761 2026-06-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/212475 Title: A responder-informed gut microbial consortium enhances anti-PD-1 efficacy in a mouse cancer model Authors: Jeong, Uk Jin; Ali, Mohammed; Park, Yun Jee; You, Jin Sun; Yoon, Sang Sun Abstract: Aim: Immune checkpoint inhibitors (ICIs), particularly anti-programmed cell death protein 1 (PD-1) therapy, have improved cancer treatment outcomes, yet durable benefit is achieved in only a subset of patients. Growing evidence implicates the gut microbiome as a modulator of ICI responsiveness, but defined and experimentally validated microbial strategies remain limited. This study aimed to identify responder-associated gut microbes and to evaluate a defined bacterial consortium for enhancing PD-1 blockade efficacy. Methods: Publicly available shotgun metagenomic datasets from anti-PD-1-treated cancer patients were re-analyzed to compare gut microbiome profiles between responders and non-responders. Bacterial taxa reproducibly enriched in responders were selected based on consistency across analytical criteria and cultivability and assembled into a four-strain consortium (UJ-04). The immune-adjuvant potential of UJ-04, alone or combined with anti-PD-1 therapy, was evaluated in a B16-F10 melanoma mouse model, with tumor growth and immune responses assessed by flow cytometry. Results: Metagenomic re-analysis identified four commensal bacterial taxa consistently enriched in responder patients, forming the defined UJ-04 consortium. While UJ-04 alone showed minimal antitumor activity, combination treatment with anti-PD-1 significantly enhanced tumor growth inhibition compared with anti-PD-1 monotherapy. This effect was accompanied by increased intratumoral CD8+T cells and natural killer cells, with concordant immune trends in peripheral compartments. Conclusion: A responder-informed, defined microbial consortium functionally translates clinical microbiome associations into in vivo validation and enhances PD-1 blockade efficacy by modulating host antitumor immunity. These findings support defined bacterial consortia as microbiome-based immunomodulatory adjuncts for immunotherapy. Mon, 01 Jun 2026 00:00:00 GMT https://ir.ymlib.yonsei.ac.kr/handle/22282913/212475 2026-06-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/212556 Title: Virtual reality-based cognitive assessment tools for mild cognitive impairment screening: comparison with traditional paper-and-pencil-based cognitive assessment tools Authors: Lee, Seungryul; Jang, Sooah; Kim, Eosu; Son, Sang Joon; Kim, Woo Jung; Lee, San; Hong, Chang Hyung; Roh, Hyun Woong; Seok, Jeong-Ho; Jung, Eunjin; 김지혜; Kim, In-young; Oh, Jooyoung; 장수아; 이산 Abstract: Background and Objectives Dementia is becoming increasingly prevalent, highlighting the need for early detection of mild cognitive impairment (MCI), a risk state for dementia. Traditional cognitive assessments often require trained examiners and lack ecological validity. This study examined the diagnostic accuracy of a virtual reality (VR)-based cognitive assessment tool, VARABOM.D, by comparing it with three standard tests: Seoul Neuropsychological Screening Battery (SNSB), Montreal Cognitive Assessment (MoCA), and Mini-Mental State Examination (MMSE).Research Design and Methods Seventy-seven participants, divided into normal (n = 44) and MCI (n = 33) groups based on their Clinical Dementia Rating scores, completed the VARABOM.D program, in addition to SNSB, MoCA, and MMSE. Correlation analyses were performed on the test results, and the specificity, sensitivity, and area under the curve (AUC) of VARABOM.D were compared to those of the other assessments. To monitor for any adverse reactions to the VR environment, the Simulator Sickness Questionnaire (SSQ) was administered both before and after the VR sessions.Results VARABOM.D scores showed significant positive associations with established cognitive assessments. Its AUC values were comparable to those of the MoCA, MMSE, and most SNSB subdomains except for attention, where VARABOM.D demonstrated greater discriminative ability. SSQ scores remained stable across pre- and post-VR sessions in both study groups, underscoring the VR platform's safety and feasibility.Discussion and Implications VARABOM.D demonstrated accuracy comparable to traditional cognitive assessments and even outperformed the attention subdomain of SNSB. Additionally, no adverse reactions were observed in the normal or MCI groups, further emphasizing the safety and stability of VARABOM.D. Mon, 01 Jun 2026 00:00:00 GMT https://ir.ymlib.yonsei.ac.kr/handle/22282913/212556 2026-06-01T00:00:00Z