Publications by authors named "Yujin Cha"

Background: Data analysis was conducted on 20 years (1999-2019) of the Korean Time Use Survey (KTUS) to identify differences and characteristics among each types by extracting latent clusters of weekend leisure activities.

Methods: Using data from the KTUS, we classified weekend leisure time activities into 6 distinct categories. To identify the latent clusters for each year's KTUS data, we utilized latent profile analysis (LPA).

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Hydrogen sulfide (HS) is involved in various biological processes. Thereby, abnormal levels of HS are reported to be related to various human diseases including cancer. Currently, many fluorescent probes are pioneered to detect HS by taking advantages of naphthalimides' unique internal charge transfer (ICT) property.

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This study was carried out to identify the influence of a shock-absorbing insole, developed by the author for use with high-heeled shoes, on walking. The research design included single-blind randomized parallel groups; namely, a group of 26 participants who wore the shock-absorbing insoles and another group of 26 participants who did not wear the insoles, both carried out walking while wearing 7 cm high-heels. During walking, plantar pressure analysis (via in-shoe plantar pressure measurements), surface electrode electromyography (surface EMG), gait analysis, subjective comfort evaluation, and functional movement (functional mobility) analysis were carried out.

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Background And Objectives: Occupation and time-use can never be separated because they are important criteria in determining one's lifestyle, improvements of one's lifestyle, and even the quality of life. The purpose of this study was to identify whether there is a difference in time-use between the occupational balance (OB) group and occupational imbalance (OI) group and to determine the factors that influence the life satisfaction of those in the OB group.

Methods: This study sorted detailed activities of 9,228 participants who were over 65 years of age.

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The endogenous HS-driven theranostic H2S-Gem has been invented. The theranostic prodrug H2S-Gem is selectively activated in cancer cells, releasing active gemcitabine with a simultaneous fluorescence turn-on. H2S-Gem selectively inhibited cancer cell growth compared to the mother chemotherapeutic gemcitabine.

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Identification of bacterial strains is critical for the theranostics of bacterial infections and the development of antibiotics. Many organic fluorescent probes have been developed to overcome the limitations of conventional detection methods. These probes can detect bacteria with "off-on" fluorescence change, which enables the real-time imaging and quantitative analysis of bacteria and .

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Recent research on the mechanochemistry of metallocene mechanophores has shed light on the force-responsiveness of these thermally and chemically stable organometallic compounds. In this work, we report a combination of experimental and computational studies on the mechanochemistry of main-chain cobaltocenium-containing polymers. Ester derivatives of the cationic cobaltocenium, though isoelectronic to neutral ferrocene, are unstable in the nonmechanical control experimental conditions that were accommodated by their ferrocene analogs.

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Site-specific cobaltocenium-labeled polymers are synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using cobaltocenium-labeled chain transfer agents. These chain transfer agents show counterion-dependent solubility. Based on the chemical structure of the chain transfer agents, single cobaltocenium moieties are dictated to be in predetermined locations at either the center or terminals of the polymer chains.

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This study aims to comprehensively investigate whether there are any differences in the degree of biomechanical adaptation according to habituation to different heel heights. The biomechanical characteristics of 54 subjects in 3 groups habituated to three heel heights (low, medium-high, and high heels) were evaluated by the measurement of surface EMG, myotonometer (e.g.

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Polymerization-induced self-assembly (PISA) and crystallization-driven self-assembly (CDSA) are among the most prevailing methods for block copolymer self-assembly. Taking the merits of scalability of PISA and dimension control of CDSA, we report one-pot synchronous PISA and CDSA ring-opening metathesis polymerization (ROMP) to prepare nano-objects based on a crystalline poly(ruthenocene) motif. We denote this self-assembly methodology as ROMPI-CDSA to enable a simple, yet robust approach for the preparation of functional nanomaterials.

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New antimicrobial agents are needed to address ever-increasing antimicrobial resistance and a growing epidemic of infections caused by multidrug resistant pathogens. We design nanostructured antimicrobial copolymers containing multicyclic natural products that bear facial amphiphilicity. Bile acid based macromolecular architectures of these nanostructures can interact preferentially with bacterial membranes.

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Cobaltocenium-containing polyelectrolyte block copolymer nanoparticles were prepared via polymerization-induced self-assembly (PISA) using aqueous dispersion RAFT polymerization. The cationic steric stabilizer was a macromolecular chain-transfer agent (macro-CTA) based on poly (2-cobaltocenium amidoethyl methacrylate chloride) (PCoAEMACl), and the core-forming block was poly(2-hydroxypropyl methacrylate) (PHPMA). Stable cationic spherical nanoparticles were formed in aqueous solution with low dispersity without adding any salts.

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Cations are crucial components in emerging functional polyelectrolytes for a myriad of applications. Rapid development in this area necessitates the exploration of new cations with advanced properties. Herein we describe a combination of computational and experimental design of cobaltocene metallo-cations that have distinct electronic and redox properties.

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We report crystallization-driven self-assembly (CDSA) of metallo-polyelectrolyte block copolymers that contain cationic polycobaltocenium in the corona-forming block and crystallizable polycaprolactone (PCL) as the core-forming block. Dictated by electrostatic interactions originating from the cationic metalloblock and crystallization of the PCL, these amphiphilic block copolymers self-assembled into two-dimensional platelet nanostructures in polar protic solvents. The 2D morphologies can be varied from elongated hexagons to diamonds, and their stability to fragmentation was found to be dependent on the ionic strength of the solution.

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Background: This study was conducted to determine the scale and the nature of the economic burden caused by strokes and to use the results as an evidential source for determining the allocation of South Korea stroke cases in 2015.

Methods: For research subjects, the study analyzed demographic characteristics and economic burden based on data from national health insurance (NHI) claims for inpatient and outpatient cases of ischemic stroke and hemorrhagic stroke in 2015 through the Health Insurance Review and Assessment Service (HIRA) and statistical data regarding cause of death from the Korea National Statistical Office (KNSO). This study, in order to estimate economic burden due to stroke, deduced the direct and indirect costs of illness caused by stroke, using cost-of-illness (COI) methods.

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Rationale: This study aims to investigate the correlation between the available leisure activity time and life satisfaction of the healthy elderly and the factors affecting them.

Method: For the analysis, data from the 2014 Time Use Survey (2014TUS) published by Statistics Korea (KOSTAT) was used. This study classified the detailed activities of 9228 subjects, based on the data in 2014TUS, and analyzed the differences in time use for occupation domains by age group.

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Elevated expression and aberrant activation of Ras have been implicated in breast cancer aggressiveness. H-Ras, but not N-Ras, induces breast cell invasion. A crucial link between lipid rafts and H-Ras function has been suggested.

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Background: Studies on whether mental practice (MP) in patients with stroke using action observation training (AOT) is effective in improving physical performance are still insufficient. To examine the effects of MP on both occupational performance and motor function to complement studies relevant to MP with AOT.

Methods: Subjects of this study were 3 individuals who were diagnosed with stroke.

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Objective: We conducted a systematic review and meta-analysis to identify the effect of computer-based cognitive rehabilitation (CBCR) on improving cognitive functions in patients with stroke.

Methods: Researchers performed a literature search using computerized databases such as the Cochrane Database, EBSCO (CINAHL), PsycINFO, PubMed and Web of Science. The following keywords were used: stroke, computer-based, cognitive rehabilitation, and others.

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A close association between the obesity hormone leptin and breast cancer progression has been suggested. The present study investigated the molecular mechanism for enhanced leptin expression in breast cancer cells and its functional significance in breast cancer aggressiveness. We examined whether leptin expression level is affected by the oncoprotein human epidermal growth factor receptor2 (HER2), which is overexpressed in ∼30% of breast tumors.

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Objective: Meta analysis of studies was carried out to examine the effectiveness of functional task training with mental practice on functional performance following stroke.

Search Strategy: An exhaustive search was conducted using computerized databases such as MEDLINE, PubMed, Cochrane, PsycINFO, and EBSCO (CINAHL).

Selection Criteria: The search was performed using the following keywords: stroke, functional task, mental practice, randomized controlled trial.

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