• 정보보호학회논문지
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• 제32권1호
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• pp.11-23
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• 2022

코로나19 이후 비대면 근무가 증가함에 따라 협업 툴의 사용이 증가하고 있다. 협업 툴은 다양한 기기에서의 접근성을 보장하기 위해 크로스 플랫폼(cross-platform) 형태로 개발되고 있으며, 이를 위해 Chromium 기반의 오픈소스 프레임워크인 Electron을 사용하는 것이 최신의 개발 경향이다. Electron 오픈소스 프레임워크를 사용하여 개발된 어플리케이션 Electron App의 경우 Chromium 기반 웹 브라우저와 유사한 방식으로 데이터를 저장하므로, 웹 브라우저에서 데이터를 획득하는 방법과 동일한 방법으로 어플리케이션의 데이터를 획득할 수 있다. 본 논문에서는 협업 툴 잔디(jandi), 슬랙(slack), 팀즈(microsoft teams)를 중심으로, 웹 브라우저 저장소(web storage)의 데이터 구조를 분석하고 이를 기반으로 Electron App의 메시지를 획득하는 방안을 제시한다. 잔디는 기존에 개발된 도구를 활용하여 Cache에서 메시지를 획득하였고, 슬랙, 팀즈의 경우 본 논문에서 개발한 메시지 카빙 도구를 이용하여 IndexedDB에서 메시지를 획득하였다.

• Applied Microscopy
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• 제42권4호
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• pp.179-185
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• 2012

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Neuropathological hallmarks of AD are amyloid plaques, dystrophic neurite, and alteration of subcellular organelles. However, the morpho-functional study of this degenerative process and ultimate neuronal death remains poorly elucidated. In this study, immunohistochemical and ultrastructural analyses were performed to clarify the abnormal morphological alterations caused by the progression of AD in APP/PSEN1 transgenic mice, express human amyloid precursor protein, as a model for AD. In transgenic AD mice brain, the accumulation of Amyloid ${\beta}$ plaques and well-developed dystrophic neurites containing anti-LC3 antibody-positive autophagosomes were detected in the hippocampus and cortex regions. We also found severe disruption of mitochondrial cristae using high-voltage electron microscopy and three-dimensional electron tomography (3D tomography). These results provide morpho-functional evidence on the alteration of subcellular organelles in AD and may help in the investigation of the pathogenesis of AD.

• Bulletin of the Korean Chemical Society
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• 제27권3호
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• pp.381-385
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• 2006

The temperature dependence on the electron transfer rate constant $(k_{app})$ for hydroquinone redox center in $H_2Q(CH_2)_n$SH-SAMs (n = 1, 4, 6, 8, 10, and 12) on gold electrode was investigated to obtain reorganization energy $(\lambda)$ using Laviron’s formalism and Arrhenius plot of ln $[k_{app}/T^{1/2}]$ vs. T^{-1} based on the Marcus densityof-states model. All the symmetry factors measured for the SAMs were relatively close to unity and rarely varied to temperature change as expected. The electron tunneling constant $(\beta)$ determined from the dependence of the $k_{app}$ on the distance between the redox center and the electrode surface gives almost the same $\beta$ values which are quite insensitive to temperature change. Good linear relationship of Arrhenius plot for all $H_2Q(CH_2)_n$SH-SAMs on gold electrode was obtained in the temperature range from 273 to 328 K. The slopes n Arrhenius plot deduced that $\lambda$ of hydroquinone moiety is ca. 1.3-1.4 eV irrespectively of alkyl chain length of the electroactive SAM.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.191-194
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• 1998

In this paper, the physical and conductivity properties due to the electron beam irradiation for low density polyethylene using insulating materials of the distribution cable and ultra-high voltage cable are studied. The specimens of the low density polyethylene of thickness 100[$\mu\textrm{m}$] irradiated as each 1 [Mrad], 2[Mrad], 4[Mrad], 8[Mrad], 16[Mrad] and virgin are used in this experiment. In order to measure the conductivity properties, the micro electrometer is used, the range of temperature and app1ying voltage are 20 to 120[$^{\circ}C$], from 100 to 1000[V] respectively So. as a result of the conductivity properties, it is confirmed that the conductivity is increased nearly to 50[$^{\circ}C$], and is not changed until the crystalline melting point from the temperature over 60[$^{\circ}C$] because of the defects of morphology and the formation of many trap centers by means of electron beam irradiation

• 센서학회지
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• 제30권6호
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• pp.441-445
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• 2021

The components affecting the extrinsic transconductance (g_{m_ext}) in In_0.7Ga_0.3As quantum-well (QW) high-electron-mobility transistors (HEMTs) on an InP substrate were investigated. First, comprehensive modeling, which only requires physical parameters, was used to explain both the intrinsic transconductance (g_{m_int}) and the g_{m_ext} of the devices. Two types of In_0.7Ga_0.3As QW HEMT were fabricated with gate lengths ranging from 10 ㎛ to sub-100 nm. These measured results were correlated with the modeling to describe the device behavior using analytical expressions. To study the effects of the components affecting g_{m_int}, the proposed approach was extended to projection by changing the values of physical parameters, such as series resistances (R_S and R_D), apparent mobility (𝜇_{n_app}), and saturation velocity (𝜈_sat).

• 동의생리병리학회지
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• 제30권1호
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• pp.33-39
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• 2016

Alzheimer's disease(AD), one of the most common forms of dementia, is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of β-amyloid(Aβ) peptides of 40-42 residues. Aβ has been believed to be neurotoxic and now is also considered to have a role on the mechanism of memory dysfunction. Only a few acetylcholinesterase(AChE) inhibitors have been developed for treatment of AD, although the numbers of patients are rapidly increasing within aging society. Here, we show that ethanol extract of Rosae Rugosae Flos(RR) or its butanol fraction reduce the enzyme activity of AChE and BACE1(β-site APP cleaving enzyme 1). Furthermore, We found that RR inhibits Aβ aggregation and removes Aβ aggregates by Transmission electron microscopy(TEM). In addition, RR reduces the free radical of 2, 2-diphenyl-1-picrylhydrazyl(DPPH). We suggest that Rosae Rugosae Flos may be useful as a herbal medicine to treat AD.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2006년도 Spring Conference
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• pp.123-135
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• 2006

Alzheimer's disease (AD) is the most common form of dementia in the aging population and is clinically characterized by a progressive loss of cognitive abilities. Pathologically, it is defined by the appearance of senile plaques - extracellular insoluble, congophilic protein aggregates composed of amyloid $\beta$ (A$\beta$) and neurofibrillary tangles (NFTs) - inyracellular lesions consisting of paired helical filaments from hyperphosphorylated cytoskeletal tau protein as described by Alois Alzheimer a century ago. These hallmarks still serve as the major criteria for a definite diagnosis of the disease. Consequently, one of the key strategy for drug development in this disease area focuses on reducing the concentration of cerebral A$\beta$ plaque by using substances that inhibit A$\beta$ fibril formation. We focused on developing inhibitors by synthesizing several kinds of aromatic molecules. The synthetic compounds were initially screened to evaluate the effective compound by tioflavin T fluorescence assay. The selected effective compounds were tested cytotoxicity and protective effect from A$\beta$-induced neuronal toxicity by cell based MTT assay with HT22 hippocampal neurons. The BBB permeability on effectors was also tested in in vitro co-culture model(HUVEC/C6 cell line). The behavior test wea carried out in mutant APP/PS1 transgenic mouse model of Alzheimer's disease. And inhibition of A$\beta$ fibril formation by the effective compound was monitored with transmitted electron microscopic images.

• 대한공업교육학회지
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• 제41권2호
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• pp.89-118
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• 2016

본 연구의 목적은 피지컬 컴퓨팅 플랫폼인 아두이노와 앱 인벤터를 대한민국의 자랑스런 전통 과학기술의 유산이자 세계 최초의 돌격용 철갑전선(鐵甲戰船)으로 평가되는 거북선의 모형과 융합하여, 공업계열 특성화고 학생들이 실제적인 경험을 통해 과학기술적인 지식뿐만 아니라, 그와 더불어 역사 문화유산에 대한 인식과 가치 또한 제고해 볼 수 있는 피지컬 컴퓨팅 플랫폼 기반의 모형 거북선을 개발하는데 있다. 이 연구를 통하여 얻은 결론은 다음과 같다. 첫째, 아두이노 기반의 메인 컨트롤러 설계 및 제작은 전기 전자 제어와 관련된 하드웨어 및 소프트웨어 지식을 익히고, 아두이노와 전기전자 부품간의 기본적인 상호특성과 성능을 확인하는데 도움이 된다. 둘째, 회로도 및 패턴도 설계, 기술적 프로그래밍, 모바일 앱 개발 등의 과정을 통해 회로 설계 능력, 논리적 사고력과 문제해결력을 향상시키는데 효율적이다. 셋째, 피지컬 컴퓨팅 플랫폼 기반의 모형 거북선 개발을 통해 과학기술과 인문학적 소양을 통합적으로 함양할 수 있는 기초적인 토대를 마련하였다.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.672-678
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• 2006

A new approach to fabricate an enzyme electrode was described based on the immobilization of horseradish peroxidase (HRP) on dithiobis-N-succinimidyl propionate (DTSP) self-assembled monolayer (SAM) formed on gold-nanoparticles (Au-NPs) which were electrochemically deposited onto glassy carbon electrode (GCE) surface. The overall surface area and average size of Au-NPs could be controlled by varying deposition time and were examined by Field Emission-Scanning Electron Microscope (FE-SEM). The $O_2$ reduction capability of the surface demonstrated that Au-NPs were thermodynamically stable enough to stay on GCE surface. The immobilized HRP electrode based on Au-NPs/GCE presented faster, more stable and sensitive amperometric response in the reduction of hydrogen peroxide than a HRP immobilized on DTSP/gold plate electrode not containing Au-NPs. The effects of operating potential, mediator concentration, and pH of buffer electrolyte solution on the performance of the HRP biosensor were investigated. In the optimized experimental conditions, the HRP immobilized GCE incorporating smaller-sized Au-NPs showed higher electrocatalytic activity due to the high surface area to volume ratio of Au-NPs in the biosensor. The HRP electrode showed a linear response to $H_2O_2$ in the concentration range of 1.4 $\mu$M-3.1 mM. The apparent Michaelis-Menten constant ($K _M\; ^{app}$) determined for the immobilized HRP electrodes showed a trend to be decreased by decreasing size of Au-NPs electrodeposited onto GCE.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3188-3194
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• 2014

Compound K (CK) was formulated as polymeric micelles (PM) using Pluronic$^{(R)}$ F-127 to enhance the oral absorption of CK, an intestinal bacterial metabolite of ginseng protopanaxadiol saponin. The physicochemical properties of Ck-loaded PM were characterized and an in vitro transport study using the Caco-2 cell system as well as an in vivo pharmacokinetic study using SD rats was carried out. The hydrodynamic mean particle size of CK-loaded PM (CK-PM) was $254{\pm}23.45nm$ after rehydration and the drug loading efficiency was ca. 99.9%. The FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy data supported the presence of a new solid phase in the PM. The $P_{app}$ value of in vitro Caco-2 cell permeation of CK-PM and the oral absorption of CK was enhanced about 1.2-fold and 2.6-fold compared to CK suspension, respectively, showing that the present PM formulation enabled an enhancement of oral CK absorption.