• Journal of Photoscience
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• v.3 no.2
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• pp.85-90
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• 1996

The binding ability of leaf nuclear extracts to the lighbresponsive elements (LREs) of cab promoters of Arabidopsis thaliana has been investigated. The cab promoters were fragmented with restr ction endonucleases into LRE that were identified by Mitra et al. [Plant Mol. Biol. 12, 169179 ( 1989)] and other small fragments. After end labeling with Klenow fragment, the fragments were assayed for binding with the leaf nuclear proteins that were prepared by solubilizing the purified nuclei with 0.5 M ammonium sulfate. The binding ability was assayed by mobility shift assay. To perform successful mobility shift assay, several factors affecting the interaction of protein with DNA were optimized before performing the assay. The LREs had several retardation bands. However, the other promoter fragments from the transcription start site to the far upstream region of the promoters had also retardation bands. No particular relationships could be found between the retardation band distributions and the loci of LRE. It is likely that the light-regulation of cab gene expression may be controlled by the multiple interactions of the regulatory protein factors with DNA motifs.

• Biomedical Science Letters
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• v.29 no.3
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• pp.103-108
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• 2023

Enhancers are cis-elements to regulate transcription of cell/tissue-specific genes in multicellular organisms. These elements locate in upstream or downstream regions of target genes and are found in a long distance up to 100 Kb in some cases. Transcription factors and coactivators bind to enhancers in a chromatin environment. Enhancers appear to facilitate the transcription of target genes by communicating with promoters and activating them. As transcription activation mechanism of enhancers, chromatin looping between enhancers and promoters, tracking of enhancer activity to promoters along the intervening regions, and movement of enhancers and promoters into transcription condensates have been suggested based on various molecular and cellular biology studies. These mechanisms are likely to act together rather than exclusive each other for gene transcription. Understanding of enhancer action mechanism may provide a way to regulate the transcription of cell/tissue-specific genes relating with aging or various diseases.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2277-2288
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• 1996

This study was performed to analyze the cooling effect of heated ribs which are frequently used for cooling of electronic parts, using the numerical method. To prevent the excessive pressure drop due to turbulence promoters for the enhancement of heat transfer rate especially, the effect of the angle of turbulence promoter was investigated by the numerical analysis. Heat transfer rate with turbulence promoters with rectangular cross-section increased by 13% in average, but the coefficient of pressure drop increased by 1.68 times than that without them. In the present study, triangular cross-sectional shape turbulence promoters were suggested and numerically tested. Pressure drop of turbulence promoter with the 30 degree triangular cross-sectional shape decreased by 30% from that of rectangular cross-section promoters while heat transfer rate was almost the same. While with 4 turbulence promoters, the heat transfer rate increased by 21%, the pressure drop increased 4 times. It means that the higher capacity of cooling fan should be needed. With the triangular cross-sectional shape, the size of vortex region at the rear of promoters became considerably smaller, so pressure drop became smaller. The effect of the change of cross-sectional shape was not found in the flow pattern near the ribs, so that heat transfer characteristics in the ribs were not changed.

• Journal of Adhesion and Interface
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• v.19 no.4
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• pp.145-153
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• 2018

In this study, adhesion promoters with acrylate and carboxylic acid moiety were synthesized from malenized polybutadiene and 2-hydroxyethyl acrylate for producing adhesive film with low water absorption and high adhesion. The surface properties, adhesion strength, mechanical properties and water absorption of adhesive films were characterized according to the amount of acrylate and carboxylic acid in the synthesized adhesion promoters. As the carboxylic acid in the adhesion promoters increased, the adhesion strength showed a tendency to increase and the mechanical properties also improved compared to the commercial adhesion promoter. The compatibility of adhesion promoters improved remarkably due to the presence of polybutadiene (hydrophobic nature), maleic anhydride (hydrophilic nature) and carboxylic acid (hydrophilic nature).

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.39-48
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• 2021

Droughts are one of the abiotic stresses that hinders the growth and productivity of crop plants. Coping with abiotic stress is necessary to understand the molecular regulatory networks that makes plants respond to adverse environmental conditions. In our experiment to find a combination that can cope with abiotic stress (respond to drought), we screened 5 stress-inducible promoters that are expressed only under stress conditions. This founded 36 cis-elements in stress-inducible promoters. With the result we designed 2 synthetic promoters (BL1, BL2) for fine-controlled regulation by assembling cis-elements from the native promoters, which are expressed only under stress caused by droughts. Analysis of the transgenic plant (BL1-GUS, BL2-GUS) showed that the synthetic promoters increased the expression of β-glucuronidase (GUS) in transgenic plants under desiccation. Also in the transient activation assay demonstrated that synthetic promoters induced the co-transformation of effector DREB1A and DREB2C. These results expect that the synthetic promoter with a combination of drought-specific elements can be used to respond to various abiotic stress and is resistant to stress without causing growth retardation.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.123-135
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• 2001

Application of growth promoters by means of implantation or supplementation to the diets has been routine in the beef cattle industry of many countries for the better performance in growth and improvement of feed efficiency. Anabolic implants (zeranol, trenbolone acetate, and estradiol with testosterone or progesterone) have generated various positive effects. Zeranol implantation, in general, improved average daily gain (ADG), feed conversion (FC), dressing percentage (DP) and yield grade (YG) of cattle, and increased dry matter intake (DMI). Trenbolone acetate with or without estradiol also increased mean values of ADG and loin eye area (LEA) but reduced DMI and improved FC of cattle. Estradiol with testosterone or progesterone increased ADG and DMI. Anabolic implants, however, had minimal or negative effects on marbling or quality grade. The magnitude of the response to these anabolic implants in performance of beef cattle has varied depending on the type of implants, amount and duration of exposure, age of animals and combination of implants. Administration of bovine somatotropin improved ADG and FC, and decreased fat deposition. Ionophores improved FC in cattle from reduced DMI without great response to ADG. Supplementation of monensin and lasalocid reduced molar proportion of propionate. Monensin and lysocellin increased apparent absorption and retention of some minerals in cattle. Despite the improved cattle performance in growth and FC, results in beef quality from the application of the growth promoters appeared to vary or in conflict under a variety of environmental conditions.

• Toxicological Research
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• v.26 no.4
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• pp.301-313
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• 2010

Growth promoters including hormonal substances and antibiotics are used legally and illegally in food producing animals for the growth promotion of livestock animals. Hormonal substances still under debate in terms of their human health impacts are estradiol-$17\beta$, progesterone, testosterone, zeranol, trenbolone, and melengestrol acetate (MGA). Many of the risk assessment results of natural steroid hormones have presented negligible impacts when they are used under good veterinary practices. For synthetic hormonelike substances, ADIs and MRLs have been established for food safety along with the approval of animal treatment. Small amounts of antibiotics added to feedstuff present growth promotion effects via the prevention of infectious diseases at doses lower than therapeutic dose. The induction of antimicrobial resistant bacteria and the disruption of normal human intestinal flora are major concerns in terms of human health impact. Regulatory guidance such as ADIs and MRLs fully reflect the impact on human gastrointestinal microflora. However, before deciding on any risk management options, risk assessments of antimicrobial resistance require large-scale evidence regarding the relationship between antimicrobial use in food-producing animals and the occurrence of antimicrobial resistance in human pathogens. In this article, the risk profiles of hormonal and antibacterial growth promoters are provided based on recent toxicity and human exposure information, and recommendations for risk management to prevent human health impacts by the use of growth promoters are also presented.

• The Plant Pathology Journal
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• v.21 no.1
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• pp.13-20
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• 2005

Chlorella viruses are large icosahedral, plaque-forming, dsDNA viruses that infect certain unicellular, chlorellalike green algae. The genomic DNA of over 300 kb contains many useful genes and promoters. Over 40 chlorella viruses have been isolated from fresh water in Korea since 1998. The viruses were amplified initially in chlorella strain NC64A, and pure isolates were obtained by repeated plaque isolation. SDS-PAGE analysis revealed similar but distinct protein patterns, both among the group of purified viruses and in comparison with the prototype chlorella virus PBCV-1. Digestions of the 330- to 350-kb genomic DNAs with 10 restriction enzymes revealed different restriction fragment patterns among the isolates. The tRNA-coding regions of 8 chlorella viruses were cloned and sequenced. These viruses contain 14-16 tRNA genes within a 1.2- to 2-kb region, except for the SS-1 isolate, which has a 1039-bp spacer in a cluster of 11 tRNA genes. Promoter regions of several early genes were isolated and their activities were analyzed in transformed chlorella. Some promoters showed stronger activity than commonly used CaMV 35S promoter and chlorella transformation vectors for heterologous protein are beings constructed using these promoters.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.242-252
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• 2012

Seed storage oils are essential resources for not only human and animal diets but also industrial applications. The primary goal of this study was to increase seed oil content through comparative analysis of two seed-specific promoters, AtFAE1 from Arabidopsis Fatty Acid Elongase 1 gene and BnNapin from Brassica napus seed storage protein gene. AtWRI1 and AtDGAT1 genes encoding an AP2-type transcription factor and a Diacylglycerol Acyltransferase 1 enzyme, respectively, were expressed under the control of AtFAE1 and BnNapin promoters in Arabidopsis. The total seed oil content in all transgenic plants was increased by 8-11% compared with wild-type seeds. The increased level of oil content in AtWRI1 and AtDGAT1 transgenic lines under the control of both promoters was similar, although the activity of the BnNapin promoter is much stronger than that of AtFAE1 promoter in the mature stage of developing seeds where storage oil biosynthesis occurs at a maximum rate. This result demonstrates that the AtFAE1 promoter as well as the BnNapin promoter can be used to increase the seed oil content in transgenic plants.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.166-169
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• 2012

In several biotechnological applications of living bacterial cells with inducible gene expression systems, the extent of overexpression and the specificity to the inducer are key elements. In the present study, we established the concentration ranges of $Zn^{2+}$, $Ni^{2+}$, $Co^{2+}$, ${AsO_2}^-$, and $Cd^{2+}$ ions that caused significant activation of the respective promoters of Synechocystis sp. without concomitant unspecific stress responses. The low expression levels can be increased up to 10-100-fold upon treatments with $Cd^{2+}$, ${AsO_2}^-$, $Zn^{2+}$, and $Co^{2+}$ ions and up to 800-fold upon $Ni^{2+}$ treatment. These results facilitate the development of conditional gene expression systems in cyanobacteria.