Publications by authors named "Jinkyu Han"

We demonstrate the facile fabrication of metal-wire-embedded microtrenches interconnected with semiconducting ZnO nanowires (ZNWs) through the continuous mechanical machining of micrograting trenches, the mechanical embedding of solution-processable metal wires therein, and the metal-mediated hydrothermal growth of ZNWs selectively thereto. The entire process can be performed at room or a very low temperature without resorting to vacuum, lithography, and etching steps, thereby enabling the use of flexible polymer substrates of scalable sizes. We optimize the fabrication procedure and resulting structural characteristics of this nanowire-interconnected flexible trench-embedded electrode (NIFTEE) architecture.

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Polyphenols have been well-established to exert sedative-hypnotic effects in psychopharmacology. Lime (Citrus aurantifolia) peel is rich in biologically active polyphenols; however, the effects of lime peel extract on sleep have not yet been demonstrated. A comparison was conducted in mice, between the sleep-promoting effects of a standardized lime peel supplement (SLPS) and a well-known hypnotic drug, zolpidem, and its hypnotic mechanism was investigated using in vivo and in vitro assays.

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Scanning Electron Microscopy (SEM) images provide a variety of structural and morphological information of nanomaterials. In the material informatics domain, automatic recognition and quantitative analysis of SEM images in a high-throughput manner are critical, but challenges still remain due to the complexity and the diversity of image configurations in both shape and size. In this paper, we present a generally applicable approach using computer vision and machine learning techniques to quantitatively extract particle size, size distribution and morphology information in SEM images.

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Article Synopsis
  • Nanomaterials have various useful applications, but their synthesis is often a lengthy and complex process, making it hard for researchers to keep up with the information needed for development.
  • To address this, scientists created tools to extract and organize data from approximately 35,000 articles about nanomaterials, streamlining the access to synthesis protocols and chemical information.
  • The effectiveness of these tools was demonstrated with high accuracy in predicting nanomaterial composition and morphology, as well as analyzing images to assess sizes, ultimately helping researchers find trends and insights for future studies.
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Objective: Restless legs syndrome (RLS) is a highly heritable and common neurological sensorimotor disease disturbing sleep. The objective of study was to investigate significant gene for RLS by performing GWA and replication study in a Korean population.

Methods: We performed a GWA study for RLS symptom group (n=325) and non-RLS group (n=2,603) from the Korea Genome Epidemiology Study.

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Understanding the key parameters necessary for generating uniform Er,Yb co-activated NaYF possessing various selected phases (i.e. cubic or hexagonal) represents an important chemical strategy towards tailoring optical behavior in these systems.

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As a model system to probe ligand-dependent charge transfer in complex composite heterostructures, we fabricated double-walled carbon nanotube (DWNT)-CdSe quantum dot (QD) composites. Whereas the average diameter of the QDs probed was kept fixed at ∼4.1 nm and the nanotubes analyzed were similarly oxidatively processed, by contrast, the ligands used to mediate the covalent attachment between the QDs and DWNTs were systematically varied to include p-phenylenediamine (PPD), 2-aminoethanethiol (AET), and 4-aminothiophenol (ATP).

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Article Synopsis
  • - Researchers developed new semiconducting heterostructures by attaching cadmium selenide (CdSe) quantum dots to porous, rare-earth-doped alkaline earth titanate microspheres (specifically Eu and Pr doped CaTiO3) using advanced synthetic techniques.
  • - Optical tests revealed that the charge transfer behavior in these structures varied based on factors like dopant type, reaction temperature, and particle size, with 2.7 nm CdSe QDs combined with CaTiO3 spheres showing significant photoluminescence (PL) emissions.
  • - Among the tested materials, CaTiO3 proved to be the best host for the QDs, with notable results showing effective charge transfer, evidenced by a
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Double-walled carbon nanotube (DWNT)-CdSe heterostructures with the individual nanoscale building blocks linked together by 4-aminothiophenol (4-ATP) have been successfully synthesized using two different and complementary routes, i.e. covalent attachment and non-covalent π-π stacking.

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  • Researchers are exploring the hypnotic effects of phlorotannins, a type of marine plant polyphenol, as potential new sleep medications.
  • The study assessed how phlorotannins and their key component, eckstolonol, impact sleep in mice compared to diazepam using EEG and EMG monitoring.
  • Results showed that both substances decreased sleep onset time and increased non-rapid eye movement sleep, with their effects linked to the GABAA receptor, suggesting they could lead to new herbal treatments for insomnia.
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To enhance the mechanical stability of a two-dimensional photonic crystal slab structure and maintain its excellent performance, we designed a glass-embedded silicon photonic crystal device consisting of a broad bandwidth waveguide and a nanocavity with a high quality (Q) factor, and then fabricated the structure using spin-on glass (SOG). Furthermore, we showed that the refractive index of the SOG could be tuned from 1.37 to 1.

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Water-soluble, polyelectrolyte-grafted multiwalled carbon nanotubes (MWCNTs), MWCNT-g-PSSNa, were synthesized using a "grafting to" route. MWCNT-g-PSSNa thin films fabricated by an electrostatic spray (e-spray) technique were used as the counter electrode (CE) for dye-sensitized solar cells (DSSCs). The e-sprayed MWCNT-g-PSSNa thin-film-based CEs (MWCNT-CE) were uniform over a large area, and the well-exfoliated MWCNTs formed highly interconnected network structures.

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Article Synopsis
  • * Out of 2,336 students surveyed, a significant portion showed signs of Internet addiction, with higher EDS rates among those classified as addicts (37.7%) compared to possible addicts (13.9%) and non-addicts (7.4%).
  • * Findings suggest that Internet addiction notably increases the likelihood of experiencing EDS in adolescents, indicating the need for awareness and assessment of Internet habits in those with sleep issues.
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Objective: To investigate the pathophysiological relationship between RLS and small fiber neuropathy using the cutaneous silent period (CSP), which is a spinal reflex mediated by Adelta cutaneous afferents and is useful for the evaluation of small-diameter nerve function.

Methods: The CSP was measured from the extensor digitorum brevis in 157 patients with RLS and 60 healthy controls. The CSP measurement was repeated in the RLS patients after dopamine agonist treatment for one month.

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This study investigated the psychophysiological effects of sleep deprivation on auditory event-related potentials (AERPs) and their relationship with psychological parameters. Twenty-four subjects remained awake for 37 h under continuous surveillance. In the mornings and the evenings of 2 consecutive study days, AERPs were recorded and 4 self-rated scales (sleepiness, fatigue, anxiety, and mood) were quantified.

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