• Journal of Power Electronics
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• 제11권5호
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• pp.759-766
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• 2011

This paper focuses on monitoring and predicting the short circuit faults of the rotor windings of large turbo-generator systems. For the purpose of increasing efficiency and decreasing maintenance cost, a method that combines the HHT (Hilbert Huang Transform) with a wavelet has been studied. This method is based on analyzing a classical Albright detecting coil. Due to the Empirical Mode Decomposition (EMD) and the Intrinsic Mode Functions (IMF) of the HHT the exact location of a short circuit of rotor windings may be given. However, a part of the useful information is eliminated by the unreasonable decomposing scale of the wavelet. Based on the thermodynamics modeling method, this study was illustrated with a 50MW turbo-generator system that is installed in Northern China. The analysis results, which have very good agreement with those of a previous study, show that the method of combining the HHT with a wavelet is an effective way to analyze and predict the short circuit faults of the rotor windings of large generators, such as supercritical turbo-generator systems and wind turbo-generator systems. This work can offer a useful reference for analyzing smart grids by improving the power quality of a distribution network that is supplied by a turbo-generator system.

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.562-569
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• 2019

Niacinamide (NIA) is a water-soluble vitamin that is widely used in the treatment of skin diseases. Moreover, NIA displays antioxidant effects and helps repair damaged DNA. Recent studies showed that particulate matter 2.5 ($PM_{2.5}$) induced reactive oxygen species (ROS), causing disruption of DNA, lipids, and protein, mitochondrial depolarization, and apoptosis of skin keratinocytes. Here, we investigated the protective effects of NIA on $PM_{2.5}$-induced oxidative stress in human HaCaT keratinocytes. We found that NIA could inhibit the ROS generation induced by $PM_{2.5}$, as well block the $PM_{2.5}$-induced oxidation of molecules, such as lipids, proteins, and DNA. Furthermore, NIA alleviated $PM_{2.5}$-induced accumulation of cellular $Ca^{2+}$, which caused cell membrane depolarization and apoptosis, and reduced the number of apoptotic cells. Collectively, the findings show that NIA can protect keratinocytes from $PM_{2.5}$-induced oxidative stress and cell damage.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1191-1199
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• 2021

Enteropathogenic Escherichia coli (EPEC), which belongs to the attaching and effacing diarrheagenic E. coli strains, is a major causative agent of life-threatening diarrhea in infants in developing countries. Most EPEC isolates correspond to certain O serotypes; however, many strains are non-typeable. Two EPEC strains, EPEC001 and EPEC080, which could not be serotyped during routine detection, were isolated. In this study, we conducted an in-depth characterization of their putative O-antigen gene clusters (O-AGCs) and also performed constructed mutagenesis of the O-AGCs for functional analysis of O-antigen (OAg) synthesis. Sequence analysis revealed that the occurrence of O-AGCs in EPEC001 and E. coli O132 may be mediated by recombination between them, and EPEC080 and E. coli O2/O50 might acquire each O-AGC from uncommon ancestors. We also indicated that OAg-knockout bacteria were highly adhesive in vitro, except for the EPEC001 wzy derivative, whose adherent capability was less than that of its wild-type strain, providing direct evidence that OAg plays a key role in EPEC pathogenesis. Together, we identified two EPEC O serotypes in silico and experimentally, and we also studied the adherent capabilities of their OAgs, which highlighted the fundamental and pathogenic role of OAg in EPEC.

• Wind and Structures
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• 제29권4호
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• pp.235-246
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• 2019

Wind loading is one of important loadings that should be considered in the design of large hyperbolic natural-draught cooling towers. Both external and internal surfaces of cooling tower are under the action of wind loading for cooling circulating water. In the previous studies, the wind loads on the external surface attracted concernedly attention, while the study on the internal surface was relatively ware. In the present study, the wind pressure on the internal surface of a 220 m high cooling tower is measured through wind tunnel testing, and the effect of ventilation rate of the packing layer on internal pressure is a major concern. The characteristics of internal wind pressure distribution and its effect on wind-induced responses calculated by finite element method are investigated. The results indicate that the wind loading on internal surface of the cooling tower behaves remarkable three-dimensional effect, and the pressure coefficient varies along both of height and circumferential directions. The non-uniformity is particularly strong during the construction stage. Analysis results of the effect of internal pressure on wind-induced responses show that the size and distribution characteristics of internal pressure will have some influence on wind-induced response, however, the outer pressure plays a dominant role in the wind-induced response of cooling tower, and the contribution of internal pressure to the response is small.

• Journal of Ginseng Research
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• 제46권4호
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• pp.543-549
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• 2022

Background: In physical activity or labor, the human body is in a state of high intensity stress, and all parts or physiological functions of the body respond positively to maintain or balance the need for movement. The human body has many physiological changes in the process of movement, and fatigue is the external manifestation of various complex changes inside the human body. Fatigue is also a physiological mechanism of self-protection after the body reaches a certain level of activity, which can prevent the occurrence of life-threatening excessive functional failure. The generation of fatigue is a very complex process, and its mechanism has not been concluded yet. Therefore, it is an important work to search and screen the effective components of natural plants that have anti-fatigue effect and to explore their mechanism. Methods: This was a 8-week, randomized, double-blind, placebo-controlled clinical trial. A total of 110 subjects who passed physical examination were included according to the scheme design, and randomly divided into a test group which was given KRG and a placebo control group. The calculation is carried out according to the standard of sub-high-intensity exercise test. Results: There was no adverse effect on safety index of subjects after taking red ginseng capsule. After KRG treatment, subjective strength grade is significant lower than placebo treatment. Blood lactic acid content is significantly get lower after trial in KRG group, and significant lower than placebo group. Creatine phosphokinase(CK) content is significantly get lower after trial in KRG group, and significant lower than placebo group. Conclusion: According to the criterion in the test scheme, the result shows that KRG is helpful on relieving physical fatigue.

• 문화기술의 융합
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• 제8권5호
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• pp.285-290
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• 2022

중국의 급속한 발전에 따라 중국예술과 미술관도 빠르게 부상하고 있다. 본 연구는 중국미술관의 역사와 발전과정을 분석하여 중국미술관의 근대에서 현대에 이르는 발전과정을 정리하고, 최근 현황과 트렌드를 분석하고자 하였다. 중국 미술관은 서방 선진국 미술관과 격차가 있지만, 그 격차가 점차 좁혀지고 있는 것으로 분석됐다. 양과 질적인 면에서 중국 미술관은 빠른 성장을 보여주고 있고, 최근 미술관의 트렌드를 반영하여 변화하고 있다. 이러한 성장에도 불구하고, 자금 부족으로 인한 운영난을 겪고 있고, 제도와 지원 미비와 이로 인한 발전에 대한 저항, 전문인재의 부족 등의 문제점들이 있다. 최근 세계적 관심을 받고있는 중국미술관에 관한 연구는 매우 부족하기 때문에, 본연구는 한국의 중국미술관 연구에 기여할 수 있다. 본 연구를 통해 중국미술관의 발전과정과 현황, 문제점 등을 이해할 수 있으며, 이를 바탕으로 한국 미술관의 발전에 시사점을 주고자 한다.

• 문화기술의 융합
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• 제9권3호
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• pp.371-376
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• 2023

라오즈하오(老字号)란 오랜 역사를 지닌 제품, 기술 또는 서비스를 가리키며, 중국 전통문화 배경과 깊은 역사유산을 갖고 있으며, 사회적으로 인정받아 우수한 평판을 형성한 브랜드를 의미한다. 일부 라오즈하오는 발전하고 있지만, 일부 라오즈하오는 생존의 위기에 직면하고 있으며, 중국 정부와 사회는 다양한 지원정책을 발표하여 지속적인 발전을 위해 노력하고 있다. 현재 한국에서 라오즈하오에 대한 연구가 매우 부족하기에, 본 연구는 중국 화장품브랜드 시에푸춘(謝馥春)의 역사, 현황, 경쟁력을 분석하였다. 연구결과, 시에푸춘은 중국 최초의 화장품 기업으로서, 전통문화를 계승한 제조기법을 가졌으며, 현재 상당한 시장 점유율을 유지하고 있다. 5-Forces 모델을 활용하여 시에푸춘의 경쟁력을 분석하고, 라오즈하오 기업에 대한 시사점과 발전모델을 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권3호
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• pp.801-825
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• 2024

For Internet of Things, it is more preferred to have immediate access to environment information from sensor nodes (SNs) rather than from gateway nodes (GWNs). To fulfill the goal, mutual authentication scheme between user and SNs with session key (SK) negotiation is more suitable. However, this is a challenging task due to the constrained power, computation, communication and storage resources of SNs. Though lots of authentication schemes with SK negotiation have been designed to deal with it, they are still insufficiently secure and/or efficient, and some even have serious vulnerabilities. Therefore, we design an efficient secure authentication scheme with session key negotiation (eSAS2KN) for wireless sensor networks (WSNs) utilizing fuzzy extractor technique, hash function and bitwise exclusive-or lightweight operations. In the eSAS2KN, user and SNs are mutually authenticated with anonymity, and an SK is negotiated for their direct and instant communications subsequently. To prove the security of eSAS2KN, we give detailed informal security analysis, carry out logical verification by applying BAN logic, present formal security proof by employing Real-Or-Random (ROR) model, and implement formal security verification by using AVISPA tool. Finally, computation and communication costs comparison show the eSAS2kN is more efficient and secure for practical application.

• Biomolecules & Therapeutics
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• 제32권4호
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• pp.499-507
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• 2024

Specific sensitivity of the skin to ultraviolet B (UVB) rays is one of the mechanisms responsible for widespread skin damage. This study tested whether 1,3,5-trihydroxybenzene (THB), a compound abundant in marine products, might inhibit UVB radiationinduced NADPH oxidase 4 (NOX4) in both human HaCaT keratinocytes and mouse dorsal skin and explore its cytoprotective mechanism. The mechanism of action was determined using western blotting, immunocytochemistry, NADP⁺/NADPH assay, reactive oxygen species (ROS) detection, and cell viability assay. THB attenuated UVB-induced NOX4 expression both in vitro and in vivo, and suppressed UVB-induced ROS generation via NADP⁺ production, resulting in increased cell viability with decreased apoptosis. THB also reduced the expression of UVB-induced phosphorylated AMP-activated protein kinase (AMPK) and phosphorylated c-Jun N-terminal kinase (JNK). THB suppressed UVB-induced NOX4 expression and ROS generation by inhibiting AMPK and JNK signaling pathways, thereby inhibiting cellular damage. These results showed that THB could be developed as a UV protectant.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4347-4351
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• 2015

Background: Previous studies showed that genetic polymorphisms of glutathione S-transferase P1 (GSTP1) were involved in glutathione metabolism and genetic polymorphisms of ribonucleotide reductase (RRM1) were correlated with DNA synthesis. Here we explored the effects of these polymorphisms on the chemosensitivity and clinical outcome in Chinese non-small cell lung cancer (NSCLC) patients treated with gemcitabine-cisplatin regimens. Materials and Methods: DNA sequencing was used to evaluate genetic polymorphisms of GSTP1 Ile105Val and RRM1 C37A-T524C in 47 NSCLC patients treated with gemcitabine-cisplatin regimens. Clinical response was evaluated according to RECIST criteria after 2 cycles of chemotherapy and toxicity was assessed by 1979 WHO criteria (acute and subacute toxicity graduation criteria in chemotherapeutic agents). Results: There was no statistical significance between sensitive and non-sensitive groups regarding the genotype frequency distribution of GSTP1 Ile105Val polymorphism (p>0.05). But for RRM1 C37A-T524C genotype, sensitive group had higher proportion of high effective genotype than non-sensitive group (p=0.009). And according to the joint detection of GSTP1 Ile105Val and RRM1 C37A-T524C polymorphisms, the proportion of type A (A/A + high effective genotype) was significantly higher in sensitive group than in non-sensitive group (p=0.009). Toxicity showed no correlation with the genotypes between two groups (p>0.05). Conclusions: Compared with single detection of genetic polymorphisms of GSTP1 Ile105Val or RRM1 C37A-T524C, joint detection of both may be more helpful for patients with NSCLC to receive gemcitabine-cisplatin regimens as the first-line chemotherapy. Especially, genetic polymorphism of RRM1 is more likely to be used as an important biomarker to predict the response and toxicity of gemcitabine-cisplatin combination chemotherapy in NSCLC.