• Title/Summary/Keyword: growth controls

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Biotechnological improvement of lignocellulosic feedstock for enhanced biofuel productivity and processing

  • Ko, Jae-Heung;Kim, Hyun-Tae;Han, Kyung-Hwan
    • Plant Biotechnology Reports
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    • v.5 no.1
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    • pp.1-7
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    • 2011
  • Secondary walls have recently drawn research interest as a primary source of sugars for liquid biofuel production. Secondary walls are composed of a complex mixture of the structural polymers cellulose, hemicellulose, and lignin. A matrix of hemicellulose and lignin surrounds the cellulose component of the plant's cell wall in order to protect the cell from enzymatic attacks. Such resistance, along with the variability seen in the proportions of the major components of the mixture, presents process design and operating challenges to the bioconversion of lignocellulosic biomass to fuel. Expanding bioenergy production to the commercial scale will require a significant improvement in the growth of feedstock as well as in its quality. Plant biotechnology offers an efficient means to create "targeted" changes in the chemical and physical properties of the resulting biomass through pathway-specific manipulation of metabolisms. The successful use of the genetic engineering approach largely depends on the development of two enabling tools: (1) the discovery of regulatory genes involved in key pathways that determine the quantity and quality of the biomass, and (2) utility promoters that can drive the expression of the introduced genes in a highly controlled manner spatially and/or temporally. In this review, we summarize the current understanding of the transcriptional regulatory network that controls secondary wall biosynthesis and discuss experimental approaches to developing-xylem-specific utility promoters.

Bioremediation of metal contamination groundwater by engineered yeasts expressing phytochelatin synthase (Phytochelatin synthase 발현을 통한 효모의 중금속 처리에 관한 연구)

  • ;;;Wilfred Chen
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.290-292
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    • 2004
  • Heavy metal contamination has been increased in aqueous environments near many industrial facilities, such as metal plating facilities, mining operations, and tanneries. The soils in the vicinity of many military bases are also reported to be contaminated and pose a risk of groundwater and surface water contamination with heavy metals. The biological removal of metals through bioaccumulation has distinct advantages over conventional methods; the process rarely produces undesirable or deleterious chemical byproducts, it is highly efficient, easy to operate and cost-effective in the treatment of large volumes of wastewater containing toxic heavy metals. In addition, a recent development of molecular biology shed light on the enhancing the microorganism's natural remediation capability as well as improving the current biological treatment. In this study, characteristics of the cell growth and heavy metal accumulation by Saccharomyces cerevisiae strains expressing phytochelatin syntahse (PCS) gene were studied in batch cultures. The AtCRFI gene was demonstrated to confer substantial increases in metal tolerance in yeast. PCS-expressing cells tolerated more Cd$^{2+}$ than controls.

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OxyR Regulon Controls Lipid Peroxidation-mediated Oxidative Stress in Escherichia coli

  • Yoon, Seon-Joo;Park, Ji-Eun;Yang, Joon-Hyuck;Park, Jeen-Woo
    • BMB Reports
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    • v.35 no.3
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    • pp.297-301
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    • 2002
  • Membrane lipid peroxidation processes yield products that may react with DNA and proteins to cause oxidative modifications. The oxyR gene product regulates the expression of enzymes and proteins that are needed for cellular protection against oxidative stress. Upon exposure to tert-butylhydroperoxide (t-BOOH) and 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH), which induce lipid peroxidation in membranes, the Escherichia coli oxyR overexpression mutant was much more resistant to lipid peroxidation-mediated cellular damage, when compared to the oxyR deletion mutant in regard to growth kinetics, viability, and DNA damage. The deletion of the oxyR gene in E. coli also resulted in increased susceptibility of superoxide dismutase to lipid peroxidation-mediated inactivation. The results indicate that the peroxidation of lipid is probably one of the important intermediary events in free radical-induced cellular damage. Also, the oxyR regulon plays an important protective role in lipid peroxidation-mediated cellular damage.

β-arrestin Promotes c-Jun N-terminal Kinase Mediated Apoptosis via a GABABR·β-arrestin·JNK Signaling Module

  • Wu, Jin-Xia;Shan, Feng-Xiao;Zheng, Jun-Nian;Pei, Dong-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.1041-1046
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    • 2014
  • Evidence is growing that the $GABA_B$ receptor, which belongs to the G protein-coupled receptor (GPCR) superfamily, is involved in tumorigenesis. Recent studies have shown that ${\beta}$-arrestin can serve as a scaffold to recruit signaling protein c-Jun N-terminal knase (JNK) to GPCR. Here we investigated whether ${\beta}$-arrestin recruits JNK to the $GABA_B$ receptor and facilitates its activation to affect the growth of cancer cells. Our results showed that ${\beta}$-arrestin expression is decreased in breast cancer cells in comparison with controls. ${\beta}$-arrestin could enhance interactions of the $GABA_BR{\cdot}{\beta}-arrestin{\cdot}JNK$ signaling module in MCF-7 and T-47D cells. Further studies revealed that increased expression of ${\beta}$-arrestin enhances the phosphorylation of JNK and induces cancer cells apoptosis. Collectively, these results indicate that ${\beta}$-arrestin promotes JNK mediated apoptosis via a $GABA_BR{\cdot}{\beta}-arrestin{\cdot}JNK$ signaling module.

miR-153 Silencing Induces Apoptosis in the MDA-MB-231 Breast Cancer Cell Line

  • Anaya-Ruiz, Maricruz;Cebada, Jorge;Delgado-Lopez, Guadalupe;Sanchez-Vazquez, Maria Luisa;Perez-Santos, Jose Luis Martin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.2983-2986
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    • 2013
  • MicroRNAs (miRNAs) are small, non-coding RNAs (18-25 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. In this context, the present study aimed to evaluate the in vitro effects of miR-153 inhibition in the breast carcinoma cell line MDA-MB-231. Forty-eight hours after MDA-MB-231 cells were transfected with the miR-153 inhibitor, an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was utilized to determine the effects of miR-153 on cell viability. Flow cytometry analysis and assessment of caspase 3/7 activity were adopted to determine whether miR-153 affects the proliferation rates and apoptosis levels of MDA-MB-231 cells. Our results showed that silencing of miR-153 significantly inhibited growth when compared to controls at 48 hours, reducing proliferation by 37.6%, and inducing apoptosis. Further studies are necessary to corroborate our findings and examine the potential use of this microRNA in future diagnostic and therapeutic interventions.

Isolation and characterization of Phytochrome B gene in Poplar (포플러의 Phytochrome B 유전자 분리 및 특성구명)

  • Kang, Hoduck;Lee, Keum-Young;Kang, Sang-Gu;Bae, Han-hong
    • Journal of Korean Society of Forest Science
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    • v.94 no.4 s.161
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    • pp.236-242
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    • 2005
  • Phytochrome B (PhyB) gene, which is a photoreceptor that controls plant growth under various light conditions, was cloned from Chinese hybrid poplar 'Soohang 1'. Nucleotide sequence and deduced amino acid sequences PhyB cDNA of 'Soohang' is consisted with 3,456 nucleotides and 1,156 amino acids. The cloned PhyB fragment showed 98% homology of amino acid sequences with Populus balsamifera PhyB1. According to Northern blot analysis. PhyB was up-regulated by light, while PhyB transcript was not detected under dark condition. According to this study, the cloned PhyB is induced by light and functions as photoreceptor.

Design and Implementation of An Automatic Nutrient Solution Control System (양액 자동 공급 제어 시스템의 설계 및 구현)

  • Jeong Won-Geun;Lee Byeong-Ro;Kim Byungcheul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.5
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    • pp.1059-1065
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    • 2005
  • In this study, an nutrient solution control system have been designed and implemented, which controls the density of nutrient and the nutrient supply automatically using embedded real time operating system and fuzzy control algorithm. The factors which affect the growth of crop consist of solar radiation, external temperature, and external humidity. Also, nutrient temperature, electric conductivity(ED, and pH are monitored. According to the surveyed results, a fuzzy control algorithm for nutrient control is developed in order to control the density of nutrient and the nutrient supply. The exclusive embedded controller which consists of an embedded real time operating system, a korean LCD, and a graphic is developed for common users.

Security System for Location-Based Services (위치 기반 서비스의 보안 시스템)

  • Park, Chan Hyun;Lee, Jaeheung;Park, Yongsu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.161-164
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    • 2012
  • Location-Based Services(LBS) are a general class of computer program-level services used to include specific controls for location data as control features in computer programs. In recent years, the number of smart device(Smart Phone, Tablet PC etc.) users growth was exponential. For that reason, using rate of LBS has drastically increased. The most important thing of LBS is security. Personal information, especially private information likes illness, should not be disclosed. In this paper shows how to attack LBS and how to defense it.

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Effect of HRE and Bcl-2 on the Production of Plasminogen Activator in CHO cells

  • Bae, Geun-Won;No, Jeong-Gwon;Lee, Gyu-Min;Kim, Ik-Yeong;Kim, Ik-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.261-264
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    • 2002
  • CHO (Chinese hamster ovary) cells were transfected with plasmids containing both cis-acting HRE (hypoxia response element) and CMV-promoter that controls tissue-type plasminogen activator (t-PA). CHO cells with HRE produced 16.2 fold higher t-PA concentration than CHO cells without HRE. It was noted that hypoxia strongly induced CHO cell apoptosis. which resulted in decrease of cell viability and protein production. In this study. by introducing Bcl-2, anti-apoptotic gene, we tried to recover cell viability and increase the protein production. When batch culture of both control cells without transfection of Bcl-2 and cells transfected with Bcl-2 were performed in the absence of CoCl ι hypoxia mimic condition. the cells with Bcl-2 were effected specific cell growth rates, maximum cell density. Immunoblotting assay showed Bcl-2 was recombinant with HRE dependent t- P A expression cassette, and their expression level was depended on hypoxia. By introducing Bcl-2, both cell viability and maximum cell density could be increased.

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Performance Evaluation of Node.js for Web Service Gateway in IoT Remote Monitoring Applications

  • Nkenyereye, Lionel;Jang, Jong-Wook
    • International Journal of Advanced Culture Technology
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    • v.4 no.3
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    • pp.13-19
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    • 2016
  • The growth of mobile devices in Internet of Things (IoT) leads to a number of remote and controlling system related IoT applications. For instance, home automation controlling system uses client system such web apps on smartphone or web service to access the home server by sending control commands. The home server receives the command, then controls for instance the light system. The web service gateway responsible for handling clients' requests attests an internet latency when an increasing number of end users requests submit toward it. Therefore, this web service gateway fails to detect several commands, slows down predefined actions which should be performed without human intervention. In this paper, we investigate the performance of a web server-side platgorm based event-driven, non-blocking approach called Node.js against traditional thread-based server side approach to handle a large number of client requests simultaneously for remote and controlling system in IoT remote monitoring applications. The Node.JS is 40% faster than the traditional web server side features thread-based approach. The use of Node.js server-side handles a large number of clients' requests, then therefore, reduces delay in performing predefined actions automatically in IoT environment.