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Spatiotemporal variability of false spring events in the temperate and boreal regions
No full textFalse spring, defined as frost events occurring after vegetation growing season has begun, can lead to severe ecological and economic damage in temperate and boreal regions. While global warming generally advances the start of the growing season and extends its duration, it can paradoxically increase the risk of frost damage to vegetation during its accelerated growth stages. Here we show the spatiotemporal patterns of false spring events and identify their climatic drivers across the northern temperate and boreal regions (30- 70°N), in the period from 1950 to 2022. We examine key metrics including the number of false spring (FS) days, the start of the growing season (SOS), the last spring frost date (LSF), and the growing degree days accumulated up to LSF (GDDLSF) using observation-based temperature datasets. The results indicate that the number of FS days has increased across most regions during the recent period, despite a general decrease in overall frost days. Significant increases in FS events are notably evident in Europe, central North America, and Siberia. This increase is primarily driven by SOS advancing faster than LSF, thereby extending the exposure period during which vegetation is vulnerable to frost. Furthermore, larger GDD changes accumulated until the LSF date in many regions imply greater vulnerability, as vegetation in more developed stages is more susceptible to freezing temperatures. Accordingly, the risk of false spring can be further intensified not only by its hazard (frequency), but also by greater vulnerability (GDDLSF) and extended exposure (LSF-SOS interval). These findings enhance the fundamental understanding of the variability and drivers of false spring events. Moreover, we underscore the need for region-specific future research, as well as adaptation and mitigation strategies for both agricultural systems and natural vegetation.Master1. Introduction 1
2. Literature Review 3
2.1. Definition and shifts in the vegetation growing season 3
2.2. Mechanisms and impacts of false spring events 5
2.3. Regional variability and drivers of false spring events 7
3. Data & Methods 9
3.1. Data 9
3.2. Study area 9
3.3. Definition of key metrics: SOS, LSF, FS, and GDDLSF 11
3.3.1. Start of the growing season (SOS) 11
3.3.1.1. Temperature-based SOS estimation 11
3.3.1.2. LAI-based SOS estimation using double logistic fitting 12
3.3.2. Last spring frost (LSF) 13
3.3.3. Number of false spring (FS) events 13
3.3.4. Growing degree days until LSF (GDDLSF) 14
3.4 Statistical method 15
4. Results 17
4.1. Spatiotemporal change of total frost and false spring occurrences 17
4.2. Advancing SOS and LSF date 20
4.3. Correlation between false spring metrics and climatic factors 25
4.4. GDDLSF: proxy for vegetation vulnerability to frost 28
4.5. A case study: Increasing FS risk in South Korea 30
4.6. Validation of temperature-based SOS using satellite-derived (LAI) data 35
5. Discussion 38
6. Conclusion 42
References 43
ACKNOWLEDGEMENT 48
CURRICULUM VITAE 4
Optoelectronic Circuit Design Based on Logical Operations of Perovskite Photodetectors
No full textLight has gained significant attention as a data transmission medium due to its high processing speed, broad terahertz bandwidth, and low heat generation. To address the limitations of traditional logic circuits based on electronic transistors, optoelectronic logic circuits utilizing optical transmission have emerged as a promising alternative. In this study, a perovskite-based multifunctional logic gate is demonstrated using a back- to-back diode photodetector with bipolar photoresponse characteristics. A wide bandgap perovskite layer for visible light absorption was deposited via a one-step solution process, while a narrow bandgap perovskite layer for near-infrared absorption was fabricated using a two-step conversion process. The resulting device exhibited bipolar photoresponse, enabling its integration into circuits such as a half adder, half subtractor, 4×2 encoder, and 2×4 decoder. These circuits, powered exclusively by light, were validated through current measurements and LED outputs driven by amplified currents. These results emphasize the potential of perovskite devices for optical computing, offering a pathway toward advanced logic circuits and data processing systems. Keywords: Perovskite photodetectors, Bipolar photoresponse, Perovskite logic gates, Optoelectronic circuits, Optical computing, Combinational logic circuitsMasterAbstract i
Contents ii
List of Figures iii
1. Introduction 1
1.1 Metal halide perovskite materials 1
1.2 Tunable bandgap of perovskite materials 2
1.3 Fabrication methods for perovskite thin film 3
1.4 Device architectures of perovskite photodetector 5
1.5 Combinational logic circuits 7
2. Experimental method 9
2.1 Materials 9
2.2 Preparation of a precursor mixture 9
2.3 Fabrication of the vertically stacked perovskite photodetector 10
2.4 Amplifier circuit design 10
2.5 Perovskite film analysis and device characterization 11
3. Results and Discussion 12
4. Conclusion 20
5. References 21
6. Supplementary information 24
ii
GHK Tripeptide functionalized with self-assembled peptide-gold nanoparticles for therapeutic applications
No full textGlycyl-L-histidyl-L-lysine(GHK) tripeptides are known for therapeutic potential like wound-healing, anti-inflammatory activity, and cellular regeneration. However, there has a problem about poor biological stability and limited efficacy in a physiological medium. Supramolecular peptide nanofiber-gold nanoparticle nanohybrids functionalized with
GHK tripeptides overcome these limitations and enhances therapeutic efficacy and material ability. 9-fluorenylmethoxycarbonyl- diphenylalanine scaffolds with GHK and KHG tripeptides form self-assembled fibrillar structures. Amino acid sequence influences surface exposure of lysine can impact wound-healing capabilities. Au NPs are spatially confined within the peptide nanofibers. It shows superior near-infrared(NIR) light absorption and photothermal conversion efficiency. We overcome cytotoxicity and biodegradability concerns of conventional photothermal agents, offering a strategy for post- operative cancer therapy and tissue regeneration
An Analysis of Age-Related Body Composition Changes and Metabolic Patterns in Korean Adults Using FDG-PET/CT Health Screening Data
No full textBackground: F-18-fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) can be used to measure bone mineral density (BMD), cross-sectional muscle area (CSMA), Hounsfield units (HU) of liver and muscle, subcutaneous adipose tissue (SAT), abdominal visceral adipose tissue (VAT), and glucose metabolism. The present study aimed to identify age-related changes in body composition and glucose metabolism in Korean using opportunistic FDG-PET/CT imaging.
Methods: We analyzed FDG-PET/CT, clinical history, and laboratory data abstracted from the medical records of patients who underwent health screening at a single institute between 2017 and 2022.
Results: In total, 278 patients were included in the analysis (male:female=140:138). Age and body mass index were positively correlated in female, but negatively correlated in male. BMD decreased with age more in female, and CSMA decreased with age more in male. Muscle HU decreased with age for both sexes. In female, SAT and VAT increased with age; and in male, SAT decreased slightly while VAT remained stable. Muscle glucose metabolism showed no association with age in male but increased with age in female. CSMA correlated positively with BMD overall; and positively correlated with VAT and SAT in male only. In female only, both SAT and VAT showed negative correlations with glucose metabolism and correlated positively with muscle glucose metabolism. Liver HU values were inversely correlated with VAT, especially in female; and positively correlated with muscle glucose metabolism in female only.
Conclusion: FDG-PET/CT demonstrated distinct patterns of age-related changes in body composition and glucose metabolism, with significant differences between sexes.TRUEsciescopusdomesti
Field-resilient superconducting coplanar waveguide resonators made of Nb, NbTi, and NbTiN
No full textSuperconducting coplanar waveguide (SCPW) resonators with high internal quality factors (Qi) are essential for quantum information applications, but suffer severe Qi degradation under magnetic fields due to quasiparticle generation and vortex-induced losses. We fabricated and characterized Nb, NbTi, and NbTiN SCPW resonators with varying film thicknesses under different temperatures and in-plane magnetic fields (B||). Temperature-dependent transmission measurements agree well with Mattis-Bardeen theory, revealing kinetic inductance parameters. Comparative analysis shows that 45-nm-thick NbTi resonators maintain Qi = 1.01 x 104 at B|| = 0.4 T, satisfying the dual requirements of high Qi and strong field resilience. Owing to its moderate kinetic inductance and compatibility with conventional photolithography, NbTi emerges as a practical material platform for field-resilient SCPW resonators and hybrid quantum circuits operating in magnetic environments.FALSEsciescopuskc
Generation of stable 172 nJ, 95 fs pulses from a cavity-dumped direct-diode pumped Ti:sapphire laser
No full textWe demonstrate a diode-pumped Ti:sapphire laser capable of producing high-energy femtosecond pulses via cavity dumping. Four spectrally combined diodes were used to pump the Ti:sapphire laser directly, which was mode-locked using a semiconductor saturable absorber mirror. At a repetition rate of 100 kHz using a cavity dumper, 172 nJ and 95 fs pulses were generated, corresponding to a pulse peak power of 1.8 MW. The signal-to-noise ratio at the 100 kHz dumped frequency exhibited an extinction ratio exceeding 55 dB relative to the carrier. To the best of the authors’ knowledge, this is the highest pulse energy obtained using a direct diode-pumped Ti:sapphire laser. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.TRUEsciescopu
AttraCar: Multisensory In-Car VR with Thermal, Airflow, and Motion Feedback through Built-In Vehicle Systems
No full textWe introduce AttraCar, a novel multisensory in-car Virtual Reality (VR) platform that delivers thermal, airflow, and motion feedback using built-in vehicle systems. Leveraging the Heating, Ventilation, and Air Conditioning (HVAC) system for airflow and thermal variation, and the power seat for motion feedback, perceptual thresholds were determined through Just Noticeable Difference (JND) experiments. A user study evaluated six feedback conditions (Baseline, Ambient Airflow, Thermal Airflow, Seat Motion, Ambient Airflow + Seat Motion, Thermal Airflow + Seat Motion) during on-road VR scenarios. A subsequent on-road study demonstrates that different combinations of feedback are not only perceptually distinct but also highly effective in a dynamic VR context, significantly mitigating motion sickness and enhancing presence and haptic experience. We conclude with reflections on design considerations, integration challenges, and real-world applicability for scalable multisensory in-car VR systems utilizing existing vehicle components. © 2025 Copyright held by the owner/author(s)
Lateral flow immunoassay using plasmonic scattering
No full textThe lateral flow immunoassay (LFIA) is one of the most successful sensing platforms for real-world point-of-care (POC) testing. However, achieving PCR-level sensitivity without compromising the inherent advantages of LFIA, such as rapid and robust operation, affordability, and naked-eye detection, has remained a primary challenge. In this study, a plasmonic scattering-utilising LFIA was proposed, created by transparentising a nitrocellulose membrane and placing a light-absorbing backing card under the membrane. This LFIA minimised the background signal from its matrix, leading to substantially enhanced sensitivity and enabling naked-eye detection of the plasmonic scattering signal from gold nanoparticles without optics. Our plasmonic scattering-utilising LFIA showed an approximately 2600–4400 times higher detection limit compared with that of commercial LFIAs in influenza A assays. In addition, it exhibited 90% sensitivity in clinical validation, approaching PCR-level sensitivity, while commercial LFIAs showed 23–30% sensitivity. The plasmonic scattering-utilising LFIA plays a ground-breaking role in POC diagnostics and significantly boosts follow-up research. © The Author(s) 2025.TRUEsciescopu
Structure of complex coacervate core micelles: AB + C system
No full textThe effect of charged block length on the complex coacervate core micelles (C3Ms) formed by mixing a diblock polyelectrolyte and an oppositely charged homopolyelectrolyte (i.e., AB + C system) is investigated using dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM), and small-angle X-ray scattering (SAXS). Our findings reveal that increasing the charged length of the diblock polyelectrolyte leads to an augmentation in overall micelle dimensions, core radii, and critical salt concentration (CSC), whereas the charged length of the homopolyelectrolyte has minimal impact on these parameters. This difference is attributed to the relatively unconstrained spatial distribution of the homopolyelectrolyte within the coacervate core. We observed that AB + C C3Ms exhibit a highly swollen core and less crowded corona, consistent with the crew-cut regime of the proposed scaling relationship. Compared to AB + AC C3Ms, AB + C C3Ms show lower coronal chain density, which is potentially attributed to the reduced aggregation number of diblock polyelectrolytes. © 2024 Elsevier LtdFALSEsciescopu
LEGOLAS: Learning & Enhancing Golf Skills through LLM-Augmented System
No full textEffective skill acquisition in sports like golf requires both physical practice and proper feedback. Beyond error detection, valuable feedback helps learners understand underlying causes, refine mental representations, and enhance performance. While visual feedback (ViF) in self-training systems excels at identifying errors, it often lacks the capacity to address root causes or guide meaningful corrections—areas where verbal feedback (VeF) has proven highly beneficial. This study investigates the use of Large Language Models (LLMs) and Retrieval-Augmented Generation (RAG) to deliver expert-level VeF for self-training. The results show that LLM-generated VeF retains the proven advantages of traditional VeF, improving learners’ mental representations and facilitating consistent progress. Additionally, integrating VeF with ViF enhances learning efficiency, self-assessment confidence, and overall performance without increasing cognitive load. This approach offers a scalable solution for effective self-training, leveraging LLMs to capture the proven advantages of VeF and bridging the gap between traditional coaching and automated systems. © 2025 Copyright held by the owner/author(s)