• Molecules and Cells
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• 제38권2호
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• pp.187-194
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• 2015

Thioredoxin (TRX) is a disulfide reductase present ubiquitously in all taxa and plays an important role as a regulator of cellular redox state. Recently, a redox-independent, chaperone function has also been reported for some thioredoxins. We previously identified nodulin-35, the subunit of soybean uricase, as an interacting target of a cytosolic soybean thioredoxin, GmTRX. Here we report the further characterization of the interaction, which turns out to be independent of the disulfide reductase function and results in the co-localization of GmTRX and nodulin-35 in peroxisomes, suggesting a possible function of GmTRX in peroxisomes. In addition, the chaperone function of GmTRX was demonstrated in in vitro molecular chaperone activity assays including the thermal denaturation assay and malate dehydrogenase aggregation assay. Our results demonstrate that the target of GmTRX is not only confined to the nodulin-35, but many other peroxisomal proteins, including catalase (AtCAT), transthyretin-like protein 1 (AtTTL1), and acyl-coenzyme A oxidase 4 (AtACX4), also interact with the GmTRX. Together with an increased uricase activity of nodulin-35 and reduced ROS accumulation observed in the presence of GmTRX in our results, especially under heat shock and oxidative stress conditions, it appears that GmTRX represents a novel thioredoxin that is co-localized to the peroxisomes, possibly providing functional integrity to peroxisomal proteins.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.645-658
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• 2021

Porins are essential for the viability of Gram-negative bacteria. They ensure the uptake of nutrients, can be involved in the maintenance of outer membrane integrity and define the antibiotic or drug resistance of organisms. The function and structure of porins in proteobacteria is well described, while their function in photoautotrophic cyanobacteria has not been systematically explored. We compared the domain architecture of nine putative porins in the filamentous cyanobacterium Anabaena sp. PCC 7120 and analyzed the seven candidates with predicted OprB-domain. Single recombinant mutants of the seven genes were created and their growth capacity under different conditions was analyzed. Most of the putative porins seem to be involved in the transport of salt and copper, as respective mutants were resistant to elevated concentrations of these substances. In turn, only the mutant of alr2231 was less sensitive to elevated zinc concentrations, while mutants of alr0834, alr4741 and all4499 were resistant to high manganese concentrations. Notably the mutant of alr4550 shows a high sensitivity against harmful compounds, which is indicative for a function related to the maintenance of outer membrane integrity. Moreover, the mutant of all5191 exhibited a phenotype which suggests either a higher nitrate demand or an inefficient nitrogen fixation. The dependency of porin membrane insertion on Omp85 proteins was tested exemplarily for Alr4550, and an enhanced aggregation of Alr4550 was observed in two omp85 mutants. The comparative analysis of porin mutants suggests that the proteins in parts perform distinct functions related to envelope integrity and solute uptake.

• Journal of Ginseng Research
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• 제48권1호
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• pp.59-67
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• 2024

Background: Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract. Methods: We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ_25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting. Results: We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brainderived neurotrophic factor (BDNF) expression levels in Aβ_25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D. Conclusion: Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

• 한국경영과학회지
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• 제32권4호
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• pp.61-75
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• 2007

In ubiquitous computing, shared environments are required to adapt to people intelligently. Based on information about user preferences, the shared environments should be adjusted so that all users in a group are satisfied as possible. Although many group recommender systems have been proposed to obtain this purpose, they only consider average and misery. However, a broad range of philosophical approaches suggest that high inequality reduces social agreeability, and consequently causes users' dissatisfactions. In this paper, we propose social welfare functions, which consider inequalities in users' preferences, as alternative aggregation functions to achieve a social agreeability. Using an example in a previous work[7], we demonstrate the effectiveness of proposed welfare functions as socially agreeable aggregate functions in group recommender systems.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (D)
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• pp.189-194
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• 2007

자원 제약적인 무선 센서네트워크상에서 전송비용을 최대한 줄이기 위하여 데이터의 수집 및 처리를 분산된 형태로 처리하는 방법이 필수적이다. 이에 따라 Declarative Query Language를 이용하여 다양한 질의를 표현하고, 이와 같은 질의를 효율적으로 처리하기 위한 에너지 분산 질의처리 방법이 중요한 이슈로 부각되고 있다. 본 논문은 [3]의 확장된 논문으로써 유한 상태 머신 기반 운영체제인 SenOS상에서 질의를 처리할 수 있는 시스템의 구조 중 SenOS의 동적 재구성 기능적 특성을 적용한 SenDB의 동적 Aggregation Function 추가 기능에 대하여 살펴보았다. 아울러 [3]에서 제안한 이기종 센서노드 연동기능의 개선점 및 구현 방법에 대하여 살펴보겠다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (D)
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• pp.150-154
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• 2008

무한 웹 컨텐츠 환경에서는 사용자의 컨텐츠 선택을 용이하게 하기 위하여 메타데이터를 다양한 방법으로 수집할 수 있다. 그러나 한 가지 방법으로는 메타데이터의 수신이 제한적이고 풍부한 메타데이터 수신을 위해서는 다양한 방법을 이용해야 한다. 그래서 본 논문에서는 메타데이터 수집 방법들을 통합하는 장치를 제안하고, 통합 메타데이터의 품질 향상을 위해 통합과정에서 발생하는 중복 메타데이터의 필터링 방법을 제시 및 검증한다. 구체적으로는 현재 웹 상에서 다양하게 제공되고 있는 메타데이터 수집 기능들을 분석하고, 통합 장치의 개념적인 구조를 제시하며, 웹 상에서 많이 보급되고 있는 RSS Reader를 통해 메타데이터를 수집하고 이를 토대로 분석하여 중복 컨텐츠를 판단하는 방법을 제안하였다.

• 한국통신학회논문지
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• 제18권9호
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• pp.1257-1268
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• 1993

본 논문에서는 퍼지보상(compensative) 연산자를 이용하는 정보융합(information fusion) 방법을 제안하였다. 제안된 정보융합 방법에서는 보상적인 성질을 갖는 퍼지 총체화(aggregation) 연산자를 역오류전파(back-propagation)신경회로망의 활성화함수(activation function)로 간주하고, 이들 연산자에 수반된 파라메터들을 학습에 의해 결정한다. 결정된 연산자의 파라메터들은 학습자료에 나타난 의사 결정에 수반된 보상도를 표현할 수 있으며, 평가에 불필요한 정보원을 제거하는 성질도 가지고 있다. 제안된 정보융합 구조는 평가지수(sub-criterion)들의 만족도를 입력으로 학습에 의해 결정된 보상연산자에 의해 총체화된 만족도를 제공한다. 제안된 방법은 패턴 인식 문제와 칼라영상의 분할과 인식등 컴퓨터비죤 문제에 적용하여 그 정당성을 입증하였다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.60-60
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• 2003

GSH-dependent glutaredoxinl (Grxl) was characterized in Dictyostelium discoideum. After starvation, the mRNA levels of grx1 gene increased during aggregation, thereafter decreased up to tip formation and increased again during culmination. To investigate the function of Grxl, the protein was overexpressed in D. discoideum using actinl5 promoter, The phenotype analysis on Grxl-overexpressed cells showed the maintenance of slug stage for a long period and delayed culmination under dark condition. To corroborate these phenotype by the enzyme, the two mutant forms of Grxl (C21S and C24S) were overexpressed in D. discoideum. The phenotype of two mutant cells represented no slug formation and the early culmination on dark condition. These results indicate that Grxl might regulate the transition from slug to culminant in darkness.

• ETRI Journal
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• 제27권6호
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• pp.725-732
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• 2005

The reconfiguration management scheme changes a logical topology in response to changing traffic patterns in the higher layer of a network or the congestion level on the logical topology. In this paper, we formulate a reconfiguration scheme with a shared buffer-constrained cost model based on required quality-of-service (QoS) constraints, reconfiguration penalty cost, and buffer gain cost through traffic aggregation. The proposed scheme maximizes the derived expected reward-cost function as well as guarantees the required flow's QoS. Simulation results show that our reconfiguration scheme significantly outperforms the conventional one, while the required physical resources are limited.

• 대한의생명과학회지
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• 제24권3호
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• pp.253-262
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• 2018

Platelets are activated at sites of vascular injury via several molecules, such as adenosine diphosphate, collagen and thrombin. Full platelet aggregation is absolutely essential for normal hemostasis. Moreover, this physiological event can trigger circulatory disorders, such as thrombosis, atherosclerosis, and cardiovascular disease. Therefore, platelet function inhibition is a promising approach in preventing platelet-mediated circulatory disease. Many studies reported the involvement of mitogen-activated protein kinases (MAPKs) signaling pathways in platelet functions. However, these studies were limited. Thus, we examined MAPK signaling pathways in human platelets using specific MAPK inhibitors, such as PD98059, SB203580, and SP600125. We observed that these inhibitors were involved in calcium mobilization and influx in human platelets. They also suppressed thrombin-induced ${\alpha}$- and ${\delta}$-granule release. These results suggest that PD98059, SB203580, and SP600125 exhibit $Ca^{2+}$ antagonistic effects.