• Title/Summary/Keyword: Growth mechanism

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Codon Optimization, Soluble Expression and Purification of PE_PGRS45 Gene from Mycobacterium tuberculosis and Preparation of Its Polyclonal Antibody Protein

  • Xu, Tao;Li, Minying;Wang, Chutong;Yuan, Meili;Chang, Xianyou;Qian, Zhongqing;Li, Baiqing;Sun, Meiqun;Wang, Hongtao
    • Journal of Microbiology and Biotechnology
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    • v.31 no.11
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    • pp.1583-1590
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    • 2021
  • Studies have demonstrated that PE_PGRS45 is constitutively expressed under various environmental conditions (such as nutrient depletion, hypoxia, and low pH) of the in vitro growth conditions examined, indicating that PE_PGRS45 protein is critical to the basic functions of Mycobacterium tuberculosis. However, there are few reports about the biochemical function and pathogenic mechanism of PE_PGRS45 protein. The fact that this M. tuberculosis gene is not easily expressed in E. coli may be mainly due to the high content of G+C and the use of unique codons. Fusion tags are indispensable tools used to improve the soluble expression of recombinant proteins and accelerate the characterization of protein structure and function. In the present study, His6, Trx, and His6-MBP were used as fusion tags, but only MBP-PE_PGRS45 was expressed solubly. The purification using His6-MBP tag-specific binding to the Ni column was easy to separate after the tag cleavage. We used the purified PE_PGRS45 to immunize New Zealand rabbits and obtained anti-PE_PGRS45 serum. We found that the titer of polyclonal antibodies against PE_PGR45 was higher than 1:256000. The result shows that purified PE_PGRS45 can induce New Zealand rabbits to produce high-titer antibodies. In conclusion, the recombinant protein PE_PGRS45 was successfully expressed in E. coli and specific antiserum was prepared, which will be followed by further evaluation of these specific antigens to develop highly sensitive and specific diagnostic tests for tuberculosis.

A Study on Utilization of Vision Transformer for CTR Prediction (CTR 예측을 위한 비전 트랜스포머 활용에 관한 연구)

  • Kim, Tae-Suk;Kim, Seokhun;Im, Kwang Hyuk
    • Knowledge Management Research
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    • v.22 no.4
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    • pp.27-40
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    • 2021
  • Click-Through Rate (CTR) prediction is a key function that determines the ranking of candidate items in the recommendation system and recommends high-ranking items to reduce customer information overload and achieve profit maximization through sales promotion. The fields of natural language processing and image classification are achieving remarkable growth through the use of deep neural networks. Recently, a transformer model based on an attention mechanism, differentiated from the mainstream models in the fields of natural language processing and image classification, has been proposed to achieve state-of-the-art in this field. In this study, we present a method for improving the performance of a transformer model for CTR prediction. In order to analyze the effect of discrete and categorical CTR data characteristics different from natural language and image data on performance, experiments on embedding regularization and transformer normalization are performed. According to the experimental results, it was confirmed that the prediction performance of the transformer was significantly improved when the L2 generalization was applied in the embedding process for CTR data input processing and when batch normalization was applied instead of layer normalization, which is the default regularization method, to the transformer model.

The Various Effects of Xylitol as a Dietary Sugar Substitute on Improving Oral Health (식이 당 대체제인 자일리톨의 구강건강 증진에 미치는 다양한 효과)

  • Hwang, Yoon-Sook;Lee, Hu-Jang
    • Journal of Food Hygiene and Safety
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    • v.37 no.2
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    • pp.107-113
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    • 2022
  • A number of studies have been conducted to confirm the preventive effect of xylitol on dental caries as a whole or partial alternative to dietary sugars. This study reviewed the oral health effects of xylitol on the prevention mechanism of dental caries, the prevention of dental caries, the inhibition of mother-to-child transmission, and the oral health effects in the elderly based on existing studies on the oral health of xylitol. Carbohydrates and dietary sugars in food are fermented by acid-producing microorganisms in the mouth and produce dental plaque and acid, which cause dental caries. However, most dental decay-causing bacteria cannot produce acids by metabolizing xylitol. Xylitol, stored in cells as a non-metabolizable metabolite by Streptococcus mutans (S. mutans), affects bacterial glucose metabolism and inhibits bacterial growth. Xylitol consumption also reduces the amount of plaque and the population of S. mutans in both plaque and saliva. In addition, xylitol acts in the remineralization process. Xylitol has been confirmed to effectively prevent dental caries, inhibit mother-to-child transmission of MS, prevent dental caries, and increase salivary flow in the elderly. In conclusion, xylitol is an adequate sugar substitute for dental health, from infants to the elderly. For future studies, the researchers recommend reviewing the effects of xylitol on the oral and intestinal microbial environment and the side effects of excessive intake.

Recent Research Trends in Thioredoxin Reductase-targeted Anticancer Therapy (Thioredoxin reductase를 표적으로 하는 항암 최신 연구 동향)

  • Hwangbo, Hyun;Lee, Hyesook;Cheong, JaeHun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.32 no.1
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    • pp.63-69
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    • 2022
  • The thioredoxin reductase (TrxR) system is essential for cell survival and function by playing a pivotal role in maintaining homeostasis of cellular redox and regulating signal transduction pathways. The TrxR system comprises thioredoxin (Trx), TrxR, and nicotinamide adenine dinucleotide phosphate. Trx reduced by the catalytic reaction of the TrxR enzyme reduces downstream proteins, resulting in protection against oxidative stress and regulation of cell differentiation, growth, and death. Cancer cells survive by improving their intracellular antioxidant capacity to eliminate excessively generated reactive oxygen species (ROS) due to infinite cell proliferation and a high metabolic rate. Therefore, cancer cells have high dependence and sensitivity to antioxidant systems, suggesting that focusing on TrxR, a representative antioxidant system, is a potential strategy for cancer therapy. Several studies have revealed that TrxR is expressed at high levels in various types of cancers, and research on anticancer activity targeting the TrxR system is increasing. In this review, we discuss the feasibility and value of the TrxR system as a strategy for anticancer activity research by examining the relationship between the function of the intracellular TrxR system and the development and progression of cancer, considering the anticancer activity and mechanism of TrxR inhibitors.

The 2019 Hong Kong-Mainland China Arrangement on Mutual Assistance in Court-ordered Interim Measures: A Major Breakthrough for Hong Kong-seated International Arbitral Proceedings

  • Jun, Jung Won
    • Journal of Korea Trade
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    • v.24 no.6
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    • pp.101-114
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    • 2020
  • Purpose - This paper examines the "Arrangement Concerning Mutual Assistance in Court-ordered Interim Measures in Aid of Arbitral Proceedings by the Courts of the Mainland and of the Hong Kong Special Administrative Region" (the Arrangement), which became effective on October 1, 2019, calling on courts of mainland China and Hong Kong for reciprocal commitment in support of court-ordered interim measures in aid of arbitral proceedings. Because the Hong Kong courts have granted interim measures in aid of arbitral proceedings seated in and outside of Hong Kong even prior to the Arrangement becoming effective, this paper focuses on the significance of the Arrangement making Hong Kong the first and only seat outside of mainland China from which parties to arbitral proceedings may successfully obtain interim measures to preserve of assets, properties, and/or evidence from Chinese courts to be enforced in China. Design/methodology - The significance of interim measures in international arbitration and the existing circumstances of interim measures in support of international arbitral proceedings in mainland China and Hong Kong are discussed first in this paper. Due to the confidential nature of arbitral proceedings, while the details of applications for interim measures pursuant to the Arrangement cannot be discussed, in examining the implications of the Arrangement, the relevant and necessary information was made available from the Hong Kong International Arbitration Centre, as it is one of the six qualified arbitral institutions under the Arrangement. Findings - This groundbreaking Arrangement provides a mechanism for parties with China-related matters to more effectively resolve their disputes, the opportunity for Hong Kong to become an unparalleled seat of arbitration, and for mainland China to overcome some of its negative perceptions in international arbitration. Because the Arrangement also allows parties to directly apply for interim measures from mainland Chinese courts, parties with China-related matters should take note of this potential bypassing of the procedural hurdle, which usually requires an arbitral institution to submit such applications in China, and make strategic decisions accordingly as may be appropriate. Originality/value - Because the Arrangement is a recent yet a significant agreement calling on courts of mainland China and Hong Kong for reciprocal commitment in support of court-ordered interim measures in aid of arbitral proceedings, this study will provide useful guidance for parties with China-related matters all over the world, especially in light of China's rapid economic growth and extensive and prominent trade relationships in today's world. Parties who foresee the need for interim measures from mainland Chinese courts should designate Hong Kong as their seat of arbitration and select one of the six qualified arbitral institutions under the Arrangement to administer their arbitral proceedings in order to benefit from the Arrangement.

Influence of Drought Stress Treatment on Saponarin Content during the Growing Period of Barley Sprouts (새싹보리 재배기간 중 수분스트레스 처리가 사포나린 함량에 미치는 영향)

  • Yoon, Young-Eun;Kim, Song Yoeb;Choe, Hyeonji;Cho, Ju Young;Seo, Woo Duck;Kim, Young-Nam;Lee, Yong Bok
    • Korean Journal of Environmental Agriculture
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    • v.40 no.4
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    • pp.290-294
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    • 2021
  • BACKGROUND: Barley sprouts contain a large number of secondary metabolites such as polyphenols, saponarin, and policosanols. The synthesis of such secondary metabolites occurs as a defense mechanism against external environmental stresses. In particular, it has been widely known that drought stress (DS) increases the content of flavonoids in plants. The objective of this study was to investigate the effects of drought stress treatment on the saponarin content in barley sprouts during the growing period. METHODS AND RESULTS: In this study, changes in saponarin content with different DS exposure periods and times were evaluated under the hydroponic system. For establishing different DS treatment periods, water supply was stopped for 1, 2, and 3 days, once leaf length was at 10 cm. To control different DS treatment times, water supply was stopped for 2 days, once leaf lengths were 5, 10, and 15 cm. As a result, the water potential of barley sprouts decreased from -0.8 MPa (before DS treatment) to -1.2, -2.4, and -3.2 MPa (after DS treatment), and reversely recovered to -0.8 MPa after re-irrigation. When 10 cm leaves were subjected to DS for 1 and 2 days, the saponarin content increased by 12 and 10%, respectively, while it increased by 19% when DS was applied to the 5 cm leaves. CONCLUSION(S): The results of this study suggest that drought stress at the early stage of growth (5 cm) is most helpful to increase the saponarin content of barley sprouts.

The Impact of Online Review Content and Linguistic Style on Review Helpfulness (온라인 리뷰 콘텐츠와 언어 스타일이 리뷰 유용성에 미치는 영향)

  • Li, Jiaen;Yan, Jinzhe
    • Knowledge Management Research
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    • v.23 no.2
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    • pp.253-276
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    • 2022
  • Online reviews attract much attention because they play an essential role in consumer decision-making. Therefore, it is necessary to investigate the review attributes that affect the perceived helpfulness of consumers. However, most previous studies on the helpfulness of online reviews mainly focus on quantitative factors such as review volume and reviewer attributes. Recently, some studies have investigated the impact of review content and linguistic style matching on consumers' purchase decision-making. Those studies show that consumers consider additional review attributes when evaluating reviews in decision-making. To fill the research gap with existing literature, we investigated the impact of review content and linguistic style matching on review helpfulness. Moreover, this study investigated how the reviewers' expertise moderates the effect of the review content and linguistic style matching on the review helpfulness. The empirical results show that positive affective content has a negative effect on the review helpfulness. The negative affective content and linguistic style matching positively affect review helpfulness. Review expertise relieved the impact of negative affective content and linguistic style matching on review helpfulness. According to the mechanism confirmed in this study, online e-commerce companies can achieve corporate sales growth by identifying factors affecting review helpfulness and reflecting them in their marketing strategies.

Probiotics Increase Intramuscular Fat and Improve the Composition of Fatty Acids in Sunit Sheep through the Adenosine 5'-Monophosphate-Activated Protein Kinase (AMPK) Signaling Pathway

  • Yue Zhang;Duo Yao;Huan Huang;Min Zhang;Lina Sun;Lin Su;LiHua Zhao;Yueying Guo;Ye Jin
    • Food Science of Animal Resources
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    • v.43 no.5
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    • pp.805-825
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    • 2023
  • This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5'-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory element-binding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.

The Influence of Ethical Leadership and Collaborative Communication on IS Behavior in Organizations: The Role of Trust and Person-Organization Fit (조직 내 정보보안 행동 관련 윤리적 리더십과 협력적 커뮤니케이션의 영향: 신뢰 및 개인-조직 적합성 역할)

  • In-Ho Hwang
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.3
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    • pp.465-474
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    • 2023
  • As the effective use and strong protection of an organization's information resources are recognized as a condition for the growth of an organization, they are increasing technological and policy investments in IS(information security). However, information exposure can occur from external invasions such as hacking and incidents related to misuse and abuse by insiders. This study proposes a mechanism that considers the organizational environment and individual characteristics from the viewpoint of promoting employees' IS participation activities. In other words, the study presents the complex effects of organizational environmental factors (ethical leadership, IS collaborative communication) and personal factors (person-organization fit) on organization trust and IS voice behavior. We surveyed office workers who asked for IS-related business activities and tested hypotheses using 422 samples. As a result, ethical leadership influenced organization trust through collaborative communication, and organization trust strengthened IS voice behavior by having an interaction effect with person-organization fit. This study suggests direction for establishing an organizational environment for promoting IS-related activities by office workers, so it provides practical implications for organizations with goals related to internal information exposure control.

Evaluation Model for Lateral Flow on Soft Ground Using Commitee and Probabilistic Neural Network Theory (군집신경망과 확률신경망 이론을 이용한 연약지반의 측방유동 평가 모델)

  • Kim, Young-Sang;Joo, No-Ah;Lee, Jeong-Jae
    • Journal of the Korean Geotechnical Society
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    • v.23 no.7
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    • pp.65-76
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    • 2007
  • Recently, there have been many construction projects on soft ground with growth of industry and various construction problems concerning soft soil behavior also have been reported. Especially, foundation piles of abutments and (or) buildings which were constructed on the soft ground have been suffering from a lot of stability problems of inordinary displacement due to lateral flow of soft ground. Although many researches for this phenomena have been carried out, it is still difficult to assess the mechanism of lateral flow on soft ground quantitatively. And reliable design method for judgement of lateral flow occurrence is not established yet. In this study, PNN (probabilistic neural network) and CNN (committee neural network) theories were applied for judgment of lateral flow occurrence based on eat data compiled from Korea and Japan. Predictions of PNN and CNN models for new data which were not used during model development are compared with those predicted by conventional empirical methods. It was found that the developed PNN and CNN models can predict more precise and reliable judgment of lateral flow occurrence than conventional empirical methods.