Publications by authors named "Younggyun Kim"

Smooth muscle cells (SMCs) sense and respond to mechanical stimuli in their extracellular microenvironments (ECMs), playing a crucial role in muscle tissue engineering. Increasing evidence from topological cues-mediated mechanotransduction of SMCs in ECMs has suggested some potential underlying mechanisms of how SMC functions and maturation are regulated by their mechanosensing leading to transduction. However, how the expression of yes-associated protein 1 (YAP) influences the phenotypic shift from synthetic to contractile is still controversial.

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With the development of wearable devices and soft electronics, the demand for stretchable piezoelectric energy harvesters (SPEHs) has increased. Energy harvesting can provide energy when large batteries or power sources cannot be employed, and stretchability provides a user-friendly experience. However, the performance of SPEHs remains low, which limits their application.

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In this study, the thermodynamic and structural characteristics of natural gas hydrates (NGHs) retrieved from gas hydrate mounds (ARAON Mound 03 (AM03) and ARAON Mound 06 (AM06)) in the Chukchi Sea in the Arctic region were investigated. The gas compositions, crystalline structure, and cage occupancy of the NGHs at AM03 and AM06 were experimentally measured using gas chromatography (GC), C nuclear magnetic resonance (NMR), Raman spectroscopy, and powder X-ray diffraction (PXRD). In the NGHs from AM03 and AM06, a significantly large fraction of CH (> 99%) and a very small amount of HS were enclathrated in small (5) and large (56) cages of sI hydrate.

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Structural colors that can be changed dynamically, using either plasmonic nanostructures or photonic crystals, are rapidly emerging research areas for stretchable sensors. Despite the wide applications of various techniques to achieve strain-responsive structural colors, important factors in the feasibility of strain sensors-such as their sensing mechanism, stability, and reproducibility-have not yet been explored. Here, we introduce a stretchable, diffractive, color-based wireless strain sensor that can measure strain using the entire visible spectrum, based on an array of cone-shaped nanostructures on the surface of an elastomeric substrate.

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We present a magneto-optic sensing system based on the "off-axis" optical probing technique to control the measurement sensitivity of magnets with various field strengths. The magnetic field is experimentally investigated in the absolute scale through a photonic calibration method with a standard electromagnet. Our all-dielectric magnetic field probe has a wide dynamic range (20 mT-3 T) with good responsivity and low probe invasiveness against the magnetic field being measured.

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Objective: The purpose of this study is to report the effects of Chukyu (spine-healing) pharmacopuncture treatment in patients with lumbago and skelalgia.

Methods: This clinical study included 45 patients who were treated for lumbago and skelalgia at the Department of Acupuncture and Moxibusition, Dong-Eui University College of Oriental Medicine, from July 5, 2011, to January 31, 2012. Subjects were randomly divided into two groups: Chukyu (spinehealing)- pharmacopuncture-treated group (experimental group, n = 23) and normal saline-pharmacopuncture-treated group (control group, n = 22).

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Background: To report two cases of atypical vitelliform macular dystrophy misdiagnosed as chronic central serous chorioretinopathy.

Case Presentation: Two patients with incidentally discovered abnormalities of the retina without specific symptoms were referred to our hospital for consultation. Bilateral macula atrophic lesions were observed and optical coherence tomography revealed serous retinal detachment in the macula.

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Aim: To compare the effects of intravitreal bevacizumab on different morphologic patterns of diabetic macular edema (DME) classified using optical coherence tomography (OCT).

Materials And Methods: Medical records for 65 eyes of 48 patients were retrospectively reviewed, and each subject was classified as one of three DME types according to the OCT features: diffuse retinal thickening (DRT), cystoid macular edema (CME), serous retinal detachment (SRD). Subjects were given three monthly intravitreal injections of bevacizumab (1.

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Purpose: To describe findings of spectral domain optical coherence tomography (SD-OCT) in the diagnosis of occult macular dystrophy (OMD).

Materials And Methods: Five visually disturbed patients who had shown normal findings in full field electroretinogram (ERG), fundus photography and fluorescein angiography but abnormal findings in multifocal ERG had undergone SD-OCT. The morphologic changes in retina and macular thickness were detected and imaged by SD-OCT.

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Cost-effective production of bacterial cellulose (BC) by Acetobacter sp. V6 was investigated in shake culture using glycerol as carbon source and its structural and physical properties were determined. In medium containing 3% (w/v) glycerol, BC production was 4.

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The antimetastatic properties of soybean saponin were investigated by evaluating matrix metalloproteinase (MMP-2 and MMP-9) production in HT-1080 cells. The mRNA expression levels of MMP-2 and MMP-9 were determined by RT-PCR analysis. The levels of secreted MMP-2, MMP-9 and tissue inhibitor of metalloproteinase-2 (TIMP-2) were determined by gelatin zymography and/or ELISA.

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Objective: To observe metabolic differences between spinal tumor and other diseases in human spinal mass lesions, in vivo 1H magnetic resonance spectroscopy (MRS) was attempted to obtain metabolic signals in patients with various spinal mass lesions.

Methods: 1H nuclear magnetic resonance (NMR) spectra were obtained from 14 patients before surgery using a receive-only surface coil on a 1.5 T clinical magnetic resonance imaging (MRI) unit.

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