• Clinical and Experimental Pediatrics
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• 제55권8호
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• pp.301-305
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• 2012

Nonketotic hyperglycinemia (NKH) is a rare inborn error of amino acid metabolism. A defect in the glycine cleavage enzyme system results in highly elevated concentrations of glycine in the plasma, urine, cerebrospinal fluid, and brain, resulting in glycine-induced encephalopathy and neuropathy. The prevalence of NKH in Korea is very low, and no reports of surviving patients are available, given the scarcity and poor prognosis of this disease. In the current study, we present a patient with NKH diagnosed on the basis of clinical features, biochemical profiles, and genetic analysis. Magnetic resonance spectroscopy (MRS) allowed the measurement of absolute glycine concentrations in different parts of the brain that showed a significantly increased glycine peak, consolidating the diagnosis of NKH. In additional, serial MRS follow-up showed changes in the glycine/creatinine ratios in different parts of the brain. In conclusion, MRS is an effective, noninvasive diagnostic tool for NKH that can be used to distinguish this disease from other glycine metabolism disorders. It may also be useful for monitoring NKH treatment.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권6호
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• pp.777-788
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• 2014

This paper presents a wide output range, high power efficiency reconfigurable charge pump for driving touch panels with the high resistances. The charge pump is composed of 4-stages and its configuration automatically changes based on the required output voltage level. In order to keep the power efficiency over the wide output voltage range, internal blocks are automatically activated or deactivated by the clock driver in the reconfigurable charge pump minimizing the switching power loss due to the On and Off operations of MOSFET. In addition, the leakage current paths in each mode are blocked to compensate for the variation of power efficiency with respect to the wide output voltage range. This chip is fabricated using $0.18{\mu}m$ BCD process with high power MOSFET options, and the die area is $1870{\mu}m{\times}1430{\mu}m$. The power consumption of the charge pump itself is 79.13 mW when the output power is 415.45 mW at the high voltage mode, while it is 20.097 mW when the output power is 89.903 mW at the low voltage mode. The measured maximum power efficiency is 84.01 %, when the output voltage is from 7.43 V to 12.23 V.

• 한국통신학회논문지
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• 제40권10호
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• pp.1922-1930
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• 2015

본고에서는 초고주파 대역에서의 무선 전력 포집 성능을 검증할 수 있는 테스트 시스템의 구성과 특성을 나타내었다. 개발된 무선 전력 포집 테스트 시스템은 900 MHz와 2.4 GHz 대역을 이용한 전력 전송과 데이터 통신 시스템뿐만이 아니라 2.4 GHz 대역에서의 전력 전송 및 데이터 통신 성능 평가가 가능하며, 효율적인 전력 포집 알고리즘 개발에 적합하도록 개발 되었다.

• Korean Journal of Ophthalmology
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• 제32권6호
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• pp.459-469
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• 2018

Purpose: To evaluate changes in the peripapillary retinal nerve fiber layer (RNFL) thicknesses using spectral-domain optical coherence tomography (SD-OCT) in hydroxychloroquine (HCQ) users. Methods: The medical records of HCQ users were retrospectively reviewed. In these HCQ users, an automated perimetry, fundus autofluorescence photography, and SD-OCT with peripapillary RNFL thickness measurements were performed. The peripapillary RNFL thicknesses were compared between the HCQ users and the control groups. The relationships between the RNFL thicknesses and the duration or cumulative dosage of HCQ use were analyzed. Results: This study included 77 HCQ users and 20 normal controls. The mean duration of HCQ usage was $63.6{\pm}38.4$ months, and the cumulative dose of HCQ was $528.1{\pm}3.44g$. Six patients developed HCQ retinopathy. Global and six sectoral RNFL thicknesses of the HCQ users did not significantly decrease compared to those of the normal controls. No significant correlation was found between the RNFL thickness and the duration of use or cumulative dose. The eyes of those with HCQ retinopathy had temporal peripapillary RNFL thicknesses significantly greater than that of normal controls. Conclusions: The peripapillary RNFL thicknesses did not change in the HCQ users and did not correlate with the duration of HCQ use or cumulative doses of HCQ. RNFL thickness is not a useful biomarker for the early detection of HCQ retinal toxicity.

• Journal of Ginseng Research
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• 제46권1호
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• pp.147-155
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• 2022

Background: Methamphetamine (METH) is the most widely used psychostimulant and has been known to exhibit reinforcing effects even after long abstinence. We showed the inhibitory effect of Korean Red Ginseng extract (RGE) on METH-induced addictive behaviors in animal models mimicking the human drug-use pattern. Methods: We first investigated the effect of RGE on the acquisition of METH-induced dependence using self-administration and conditioned place preference (CPP) tests. Additionally, further experiments such as METH-induced motivational behavior and seeking behavior were conducted. To study the underlying mechanism, dopamine receptor, dopamine transporter, and N-methyl-D-aspartate receptor were assessed through Western blot analysis. Results: Treatment with RGE significantly reduced METH-induced self-administration on a fixed-ratio 1 schedule of reinforcement. It could be also decreased a progressive ratio schedule, and inhibited METH-primed reinstatement. In CPP, RGE significantly prevented the development of METH-induced CPP. Moreover, RGE not only shortened the withdrawal period clearly, but also prevented the reinstatement of CPP. RGE treatment also reversed METH-induced overexpression of dopamine transporter, dopamine receptor D1, and NMDA receptor in the nucleus accumbens. Conclusion: Our findings reflect that RGE has therapeutic potential to suppress METH-induced addictive behaviors by regulating dopaminergic and NMDAergic system.

• Biomolecules & Therapeutics
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• 제32권4호
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• pp.432-441
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• 2024

Systemic sclerosis is an autoimmune disease characterized by inflammatory reactions and fibrosis. Myofibroblasts are considered therapeutic targets for preventing and reversing the pathogenesis of fibrosis in systemic sclerosis. Although the mechanisms that differentiate into myofibroblasts are diverse, transforming growth factor β (TGF-β) is known to be a key mediator of fibrosis in systemic sclerosis. This study investigated the effects of extracellular vesicles derived from human adipose stem cells (ASC-EVs) in an in vivo systemic sclerosis model and in vitro TGF-β1-induced dermal fibroblasts. The therapeutic effects of ASC-EVs on the in vivo systemic sclerosis model were evaluated based on dermal thickness and the number of α-smooth muscle actin (α-SMA)-expressing cells using hematoxylin and eosin staining and immunohistochemistry. Administration of ASC-EVs decreased both the dermal thickness and α-SMA expressing cell number as well as the mRNA levels of fibrotic genes, such as Acta2, Ccn2, Col1a1 and Comp. Additionally, we discovered that ASC-EVs can decrease the expression of α-SMA and CTGF and suppress the TGF-β pathway by inhibiting the activation of SMAD2 in dermal fibroblasts induced by TGF-β1. Finally, TGF-β1-induced dermal fibroblasts underwent selective death through ASC-EVs treatment. These results indicate that ASC-EVs could provide a therapeutic approach for preventing and reversing systemic sclerosis.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3127-3129
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• 2011

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권2호
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• pp.127-138
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• 2012

In this paper, we propose a real-time virtual re-convergence hardware platform especially to reduce the visual fatigue caused by stereoscopy. Our unique idea to reduce visual fatigue is to utilize the virtual re-convergence based on the optimized disparity-map that contains more depth information in the negative disparity area than in the positive area. Our virtual re-convergence hardware platform, which consists of image rectification, disparity estimation, depth post-processing, and virtual view control, is realized in real time with 60 fps on a single Xilinx Virtex-5 FPGA chip.

• Applied Science and Convergence Technology
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• 제24권4호
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• pp.117-124
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• 2015

A direct growth method of graphene on insulating substrate without catalyst etching and transfer process was developed using Au/Ni/a-C catalyst system. During the growth process, behavior of the Au/Ni catalyst was investigated using EDX, XPS, SEM, and Raman spectroscopy. The Au/Ni catalyst layer was evaporated during growth process of graphene. The graphene film was composed mono-layer flakes. The transmittance of the graphene film was ~80.6%.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.978-980
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• 2004

We report the preparation and properties of polymer paste solutions with CNTs using conventional paste forming process. Electrospinning has been used for the fabrication of nano-fiber composite. In this process, dispersion of CNTs is very important matter. So, we emphasize the necessity of dispersion of CNTs in the solution and investigate effects of process parameters of electrospinning. The advantage of simple electrospinning process will be discussed..