• BMB Reports
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• 제51권6호
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• pp.265-273
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• 2018

Tau protein is encoded in the microtubule-associated protein tau (MAPT) gene and contributes to the stability of microtubules in axons. Despite of its basic isoelectric point and high solubility, tau is often found in intraneuronal filamentous inclusions such as paired helical filaments (PHFs), which are the primary constituent of neurofibrillary tangles (NFTs). This pathological feature is the nosological entity termed "tauopathies" which notably include Alzheimer's disease (AD). A proteinaceous signature of all tauopathies is hyperphosphorylation of the accumulated tau, which has been extensively studied as a major pharmacological target for AD therapy. However, in addition to phosphorylation events, tau undergoes a number of diverse posttranslational modifications (PTMs) which appear to be controlled by complex crosstalk. It remains to be elucidated which of the PTMs or their combinations have pro-aggregation or anti-aggregation properties. In this review, we outline the consequences of and communications between several key PTMs of tau, such as acetylation, phosphorylation, and ubiquitination, focusing on their roles in aggregation and degradation. We place emphasis on the structure of tau protofilaments from the human AD brain, which may be good targets to modulate etiological PTMs which cause tau aggregation.

• 한국산업정보학회논문지
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• 제20권2호
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• pp.11-18
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• 2015

As the communication technology and mobile devices develop, the need for the efficient and secure remote storage is required. And recently, many companies support cloud storages to meet the requirements of the customers. Especially in the business field where various companies collaborate, data sharing is an essential functionality to enhance their work performance. However, existing researches have not fully satisfied the requirement either efficiency and security. This paper suggests efficient and secure data sharing scheme for cloud storage by using secret sharing scheme. Proposed scheme can be applied to business collaborations and team projects.

• 순환기질환의공학회:학술대회논문집
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• 순환기질환의공학회 2002년도 제2회 학술대회 초록집
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• pp.3-18
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• 2002

Hemorheology plays an important role in atherosclerosis. Hemorheologic properties of blood include whole blood viscosity, plasma viscosity, hemaocrit, RBC deformability and aggregation, and fibrinogen concentration in plasma. Blood flow is determine by three parameters (pressure, lumen diameter, and whole blood viscosity), whole blood viscosity is one of the key physiological variables. However, the significance of whole blood viscosity has not yet not been fully appreciated. Whole blood viscosity has a unique property, non-Newtonian shear-thinning characteristics, which is primarily due to the presence of RBCs. Hence, RBC deformability and aggregation directly affect the magnitude of blood viscosity, and any factors or diseases affecting RBC characteristics influence blood viscosity. Therefore, on can see that whole blood viscosity is the causal mechanism by which traditional risk factors such as hypertension, hyperlipidemia, smoking, exercise, obesity, age, and gender are related to atherogenesis. In this regard, we included whole blood viscosity in the three key determinants of injurious pulsatile flow that results in mechanical injury and protective adaptation in the arterial system. Because whole blood viscosity is a potential predictor of cardiovascular diseases, it should be measured in routine cardiovascular profiles. Incorporating whole blood viscosity measurements into a standard clinical protocol could improve our ability to identify patients at risk for cardiovascular disease and its complications.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.809-814
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• 2003

${\beta}-amyloid$ ($A{\beta}$) peptides from the proteolytic processing of ${\beta}-amyloid$ precursor protein (${\beta}-APP$) aggregates in the brain to form senile plaques, and their aggregation plays a key role in pathogenesis of Alzheimer's disease (AD). To isolate an active compound that has an $A{\beta}$ aggregation-inhibitory activity, 2,000 microbial metabolite libraries were screened based on their ability to inhibit $A{\beta}$ aggregation by using both Congo red and thioflavin T assays. As a result, a water-soluble fraction of a soil microorganism, KK565, showed a potent $A{\beta}$ aggregation-inhibitory activity. The strain was identified as Streptomyces species, based on the cultural and morphological characteristics, the presence of diaminopimelic acid in the cell wall, and the sugar patterns for the whole-cell extract. In addition, the purification of active principle resulted in identifying a heat-unstable protein responsible for the $A{\beta}$ aggregation-inhibitory activity.

• 한국인터넷방송통신학회논문지
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• 제18권3호
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• pp.49-59
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• 2018

현재 여러 국가들은 스마트 그리드 시스템의 법적, 기술적, 비즈니스 측면에서 여러 문제점들이 발견되고 있음에도 불구하고 스마트 그리드 배치를 서두르고 있다. 스마트 그리드와 관련하여 중요한 문제는 스마트 미터기의 주된 성능을 그대로 유지하면서 미터 측정값들이 믿을 수 없는 이해집단들로부터 공격을 당하지 않도록 하는 것이다. 이러한 프라이버시 보호 문제는 하드웨어 제약사항, 보안 암호화 시스템과 보안 신호 처리와 같은 몇 가지 해결책들을 요구하고 있다. 본 연구에서는 이와 관련하여 현재 스마트 미터 프라이버시 보호 영역에서 주된 도전 문제가 되고 있는 미터 사용량 집계 암호화에 관한 하나의 접근방식을 제공한다. 개별 에너지 총 사용량에 관한 프라이버시 보호를 위해 개별 사용자 집계 함수에 잡음 가중치를 부여하는 방식을 나타낸다. 접근방식에서 준동형 암호화 성질을 충족하기 위해 잡음 가중치의 곱은 1이 된다. 단적으로 개별 에너지 사용자 집계를 알 수 없도록 하는데 있다. Diffid-Hellman 생성기를 적용하는 경우에 잡음 가중치 곱은 잡음 가중치 합으로 전환되고 가중치 합은 0이 된다. Diffid-Hellman 키 교환은 보통 512비트를 사용하기 때문에 아주 큰 키들을 사용하는 다른 Paillier 계통 암호화 방법들에 비해 보다 우수한 성능을 가진다.

• 한국산업정보학회논문지
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• 제17권7호
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• pp.17-24
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• 2012

애드혹 네트워크에서는 제한된 자원과 전력을 가지고 있기 때문에 에너지 효율적인 데이터 집계 연산이 필요하다. 현재 데이터 집계 연산에 대한 연구는 활발히 진행되고 있지만 기존의 연구에서는 노드의 밀집도를 고려하지 못하였다. 노드가 특정 영역에 밀집 되어 배치된다면 그 영역에 배치된 센서 노드들이 센싱 하는 정보는 그 연관성이 아주 강하다고 판단할 수 있다. 이는 중복된 데이터를 수집하는 효과와 같다고 볼 수 있으며, 이 정보를 전송하는데 소모되는 에너지는 낭비된다고 볼 수 있다. 제안하는 기법에서는 AMC알고리즘을 이용한 다중홉 클러스터링 환경에서 노드들이 밀집되어 있는 지역을 핫스팟 영역으로 지정하여 해당 지역에서 대표노드를 선정한다. 만약 데이터집계의뢰 메시지를 전송받으면, 주변의 노드를 대표하여 대표노드가 해당 환경 정보를 관리자에게 제공하여 중복되는 센싱 정보를 줄여 네트워크 수명을 증가시킬수 있도록 설계하였다.

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.556-560
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• 2009

Aggregation behavior of three kinds of benzindocarbocyanine dyes in aqueous methanol solution was studied by UV-Vis absorption spectrum. The results indicated that the three dyes all existed monomer-dimer equilibrium in aqueous methanol solution (concentration range $10^{−5}\;to\;10^{−6}$ M) at 25.0$\sim$41.0 ${^{\circ}C}$ for Dye 1, 28.0$\sim$49.0 ${^{\circ}C}$ for Dye 2 and 26.0$\sim$47.0 ${^{\circ}C}$ for Dye 3. The fundamental property of the three dyes as the dimeric association constant KD, the dimeric free energy ${\Delta$}G_D, the dimeric entropy ${\Delta$}S_D, and the dimeric enthalpy ${\Delta$}H_D were determined. The ${\Delta$}H_D of three dyes: Dye 1, Dye 2 and Dye 3 was -42.5, -15.1 and -18.9 kJ/mol, respectively. The experimental observations were the subject of a theoretical study including the ground-state geometries which were fully optimized using DFT at B3LYP/6-31G level. The effect of dye molecule structure on ${\Delta$}H_D was discussed by theoretical calculations.

• KSBB Journal
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• 제13권2호
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• pp.133-140
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• 1998

Using rlFN-$\alpha$ and rhGH as the model proteins, the refolding performances of the published processes were evaluated and compared. Key engineering parameters such as the type of denaturant and this concentration, protein concentration in the refolding buffer, and pH and ionic strength of the buffer were experimentally investigated. Furthermore, the role of a co-solvent of surfactant type in aggregation reduction was also studied. Of the denaturants tested (8M urea, 6M guanidine HCI, 0.5% SDS), SDS at alkaline pH (9.5) and ambient temperature gave the highest recovery yield. The SDS process was effective in the refolding of observed where dissolution proceeded better under lower strength (10 mM) but aggregation was suppressed under higher strength (>50 mM.) When PEG-4000 and/or Tween were added as co-solvent or refolding-enhancing additive, 1.6-2 times higher yield was realized. The‘masking’of the hyrophobic patches located on the surface of the protein with the surfactant molecules was believed to be responsible for the considerable reduction in aggregation during refolding.

• 정보과학회 논문지
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• 제44권7호
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• pp.703-709
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• 2017

아웃소싱 데이터베이스란 데이터 관리 및 질의 처리 등의 계산량이 많은 작업을 제 3자 서버에 위탁하는 것이다. 이를 통해 데이터 소유자는 비싼 인프라를 구축하지 않고 빅데이터를 관리할 수 있으며 여러 사용자로부터 받는 질의들을 빠르게 처리할 수 있다. 하지만 보안 위협이 항상 존재하는 네트워크의 특성상 제 3자 서버를 완전히 신뢰하기 어렵고, 그 서버가 처리한 결과도 신뢰하기 어렵다. 이처럼 신뢰할 수 없는 서버가 처리한 질의 결과가 정확한지 확인하는 것을 질의 인증이라고 하며 구간 질의, kNN 질의, 함수 질의 등 다양한 질의에 대한 인증 기법들이 연구되었다. 하지만 빅데이터 분석에 있어 활용도가 높은 집계 질의에 대한 깊이 있는 질의 인증 연구는 이루어지지 않았으며 기존 연구는 고차원이거나 서로 다른 값이 많은 데이터에 대해 비효율적이다. 본 연구에서는 집계 질의 인증을 위한 자료구조를 제안하고 이를 활용한 효율적인 증거 생성 방법과 증명 방법을 제안한다. 그리고 데이터의 상이 값 수, 레코드 개수, 차원 크기 등을 변경하며 진행한 실험 결과를 통해 제안한 기법의 성능이 우수함을 보였다.

• Biomolecules & Therapeutics
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• 제28권3호
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• pp.259-266
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• 2020

The present research work primarily investigated whether spinosin has the potential of improving the pathogenesis of Alzheimer's disease (AD) driven by β-amyloid (Aβ) overproduction through impacting the procession of amyloid precursor protein (APP). Wild type mouse Neuro-2a cells (N2a/WT) and N2a stably expressing human APP695 (N2a/APP695) cells were treated with spinosin for 24 h. The levels of APP protein and secreted enzymes closely related to APP procession were examined by western blot analysis. Oxidative stress related proteins, such as nuclear factor-erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were detected by immunofluorescence assay and western blot analysis, respectively. The intracellular reactive oxygen species (ROS) level was analyzed by flow cytometry, the levels of Aβ_1-42 were determined by ELISA kit, and Thioflavin T (ThT) assay was used to detect the effect of spinosin on Aβ_1-42 aggregation. The results showed that ROS induced the expression of ADAM10 and reduced the expression of BACE1, while spinosin inhibited ROS production by activating Nrf2 and up-regulating the expression of HO-1. Additionally, spinosin reduced Aβ_1-42 production by impacting the procession of APP. In addition, spinosin inhibited the aggregation of Aβ_1-42. In conclusion, spinosin reduced Aβ_1-42 production by activating the Nrf2/HO-1 pathway in N2a/WT and N2a/APP695 cells. Therefore, spinosin is expected to be a promising treatment of AD.