http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lee, Hyeok-Won,Park, Jung-Ho,Lee, Hee-Suk,Kim, Chun-Suk,Lee, Jin-Gyeom,Kim, Won-kyo,Ryu, Kyoung-Hwa,Ahn, Jung-Oh,Lee, Eun-Gyo,Kim, Seon-Won,Jeon, Jong-Min,Yang, Yung-Hun,Choi, Eui-Sung,Lee, Hong-Weon Society for Bioscience and Bioengineering, Japan 2019 Journal of bioscience and bioengineering Vol. No.
<P>Many volatile compounds, such as isoprene, a precursor used in the synthesis of natural rubber, have been produced through fermentation using genetically engineered microorganisms. Despite this biotechnological success, measuring the concentrations of volatile compounds during fermentation is difficult because of their high volatility. In current systems, off-line analytical methods usually lead to product loss, whereas on-line methods raise the production cost due to the requirement of complex devices. Here, we developed a novel on-line gas chromatography (GC)-based system for analyzing the concentration of isoprene with the aim to minimize the cost and requirement for devices as compared to current strategies. In this system, a programmable logic controller is used to combine conventional GC with a syringe pump module (SPM) directly connected to the exhaust pipe of the fermentor, and isoprene-containing samples are continuously pumped from the SPM into the GC using an air cylinder recycle stream. We showed that this novel system enables isoprene analysis during fermentation with convenient equipment and without the requirement of an expensive desorption tube. Furthermore, this system may be extended to the detection of other volatile organic compounds in fermentation or chemical processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This system analyzes the concentration of isoprene in aerobic fermentation. </LI> <LI> PLC is used to combine conventional GC with SPM directly connected to fermenter. </LI> <LI> Produced isoprene is continuously analyzed using the GC. </LI> <LI> This system may be extended to the detection of other volatile organic compounds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Lee, Ji Young,Kim, Hyo Jeong,Yoon, Nal Ae,Lee, Won Hyeok,Min, Young Joo,Ko, Byung Kyun,Lee, Byung Ju,Lee, Aran,Cha, Hee Jeong,Cho, Wha Ja,Park, Jeong Woo Oxford University Press 2013 Nucleic acids research Vol.41 No.11
<P>Tristetraprolin (TTP) and <I>let-7</I> microRNA exhibit suppressive effects on cell growth through down-regulation of oncogenes. Both TTP and <I>let-7</I> are often repressed in human cancers, thereby promoting oncogenesis by derepressing their target genes. However, the precise mechanism of this repression is unknown. We here demonstrate that p53 stimulated by the DNA-damaging agent doxorubicin (DOX) induced the expression of <I>TTP</I> in cancer cells. TTP in turn increased <I>let-7</I> levels through down-regulation of <I>Lin28a</I>. Correspondingly, cancer cells with mutations or inhibition of p53 failed to induce the expression of both <I>TTP</I> and <I>let-7</I> on treatment with DOX. Down-regulation of <I>TTP</I> by small interfering RNAs attenuated the inhibitory effect of DOX on <I>let-7</I> expression and cell growth. Therefore, TTP provides an important link between p53 activation induced by DNA damage and <I>let-7</I> biogenesis. These novel findings provide a mechanism for the widespread decrease in TTP and <I>let-7</I> and chemoresistance observed in human cancers.</P>
Lee, Hui-Young,Cho, Sun-A,Lee, In-Soo,Park, Jong-Hwan,Seok, Seung-Hyeok,Baek, Min-Won,Kim, Dong-Jae,Lee, Seok-Ho,Hur, Sook-Jin,Ban, Sang-Ja,Lee, Yoo-Kyoung,Han, Yang-Keum,Cho, Young-Keun,Park, Jae-Hak Oxford University Press 2007 FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY Vol.51 No.2
<P>The attenuation and immunoenhancing effects of rpoS and phoPSalmonella enterica serovar strain Typhi (Salmonella typhi) mutants have not been compared. Here, three S. typhi deletion mutants (phoP, rpoS, and rpoS-phoP double mutant) are constructed and these mutants are characterized with respect to invasiveness, virulence, and protective immune response compared with wild-type Ty2. It was found that phoP and phoP-rpoS deletion mutants are less invasive to HT-29 cells than the wild-type Ty2 and the rpoS single-deleted strain. The LD(50) of immunized mice was higher for phoP than for rpoS mutants, and the highest for the phoP-rpoS double mutant. In addition, all S. typhi mutants showed an increase in the specific serum IgG levels and T-cell-mediated immunity, and showed equal protection abilities against a wild-type Ty2 challenge after two rounds of immunization in BALB/c mice. It is concluded that phoP genes appear to play a more important role than rpoS genes in both cellular invasion and virulence of S. typhi, but not in immunogenicity in mice. Furthermore, the data indicate that the phoP-rpoS double mutant may show promise as a candidate for an attenuated typhoid vaccine.</P>
Lee, Jae-Won,Kim, Won-Ki,Oh, Yun-Sik,Seo, Hun-Chul,Jang, Won-Hyeok,Kim, Yoon Sang,Park, Chul-Won,Kim, Chul-Hwan The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3
An algorithm for fault detection and classification method for wide-area protection in Korean transmission systems is proposed. The modeling of 345-kV and 765-kV Korean power system transmission networks using the Electro Magnetic Transient Program - Restructured Version (EMTP-RV) is presented and the algorithm for fault detection and classification in transmission lines is developed. The proposed algorithm uses the Wavelet Transform (WT) and Singular Value Decomposition (SVD). The Singular value of Approximation coefficient (SA) and part Sum of Detail coefficient (SD) are introduced. The characteristics of the SA and SD at the fault conditions are analyzed and used in the algorithm for fault detection and classification. The validation of the proposed algorithm is verified by various simulation results.
Won Park, Jong,Hyeok Jeong, Jin,Yoon, Wang Lai,Kim, Chang Soo,Lee, Deuk Ki,Park, Yong-Ki,Rhee, Young Woo Elsevier 2005 International journal of hydrogen energy Vol.30 No.2
<P><B>Abstract</B></P><P>Cu–Ce/<I>γ</I>-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts promoted with Co were tested for the low temperature selective oxidation of CO in excess hydrogen. The effects of Cu–Ce composition, Co as a dopant, stoichiometric ratio (<I>λ</I>=2O<SUB>2</SUB>/CO), water vapor and CO<SUB>2</SUB> on the selective oxidation of CO to CO<SUB>2</SUB>, O<SUB>2</SUB> consumption and selectivity of O<SUB>2</SUB> to CO oxidation as a function of temperature are presented. Also, the catalytic properties of the catalysts were investigated by using X-ray diffraction, CO-/H<SUB>2</SUB>-temperature programmed reduction, temperature programmed oxidation, CO-/CO<SUB>2</SUB>-/H<SUB>2</SUB>O-temperature programmed desorption (TPD). Small addition (0.2wt) of Co onto the Cu–Ce/<I>γ</I>-Al<SUB>2</SUB>O<SUB>3</SUB> brought large increase in selective CO oxidation activity. In the presence of either CO<SUB>2</SUB> (13 vol%) or H<SUB>2</SUB>O (10 vol%) in the reformed gas feed, both Cu–Ce/<I>γ</I>-Al<SUB>2</SUB>O<SUB>3</SUB> and Cu–Ce-Co/<I>γ</I>-Al<SUB>2</SUB>O<SUB>3</SUB> showed decreased activity in CO oxidation at low temperatures, especially, under 200°C. Compared with the Cu–Ce/<I>γ</I>-Al<SUB>2</SUB>O<SUB>3</SUB>, however, the Cu–Ce-Co/<I>γ</I>-Al<SUB>2</SUB>O<SUB>3</SUB> gives higher resistivity for the CO<SUB>2</SUB> and H<SUB>2</SUB>O. From the CO<SUB>2</SUB>/H<SUB>2</SUB>O-TPD results, it could be explained that the main cause for the decrease in catalytic activity with CO<SUB>2</SUB> and H<SUB>2</SUB>O in the feed may be attributed to the competitive adsorption of CO and CO<SUB>2</SUB> as well as the blockage of the active sites by water vapor at low reaction temperatures.</P>
Won-Kyung Lee,Geon Hyeok Lee,Se-Jong Ju,Se-Joo Kim 한국동물분류학회 2021 Animal Systematics, Evolution and Diversity Vol.37 No.4
Branchinotogluma segonzaci (Miura and Desbruyères, 1995) occurs in hydrothermal vent fields of the southwestern Pacific Ocean. We morphologically compared B. segonzaci from the North Fiji Basin with the original description from the Lau Basin and a subsequent study of specimens from the Manus Basin. The main characteristics of all B. segonzaci populations were similar having 21 segments, 10 pairs of elytra, cylindrical-shaped anterior lobes, and ventral papillae on segment 12 and ventral lamellae on segments 13-17 in males. However, the specimens from the North Fiji Basin had rounded to sub-renifrom elytra rather than oval in the original description. Additionally, we newly obtained 11 cytochrome oxidase subunit I (COI) DNA barcodes from the North Fiji Basin and Tonga Arc populations and compared them with known COI DNA barcodes of Branchinotogluma species. Thirteen sequences of B. segonzaci showed 0.0-1.07% intraspecific variation and formed two clades in the COI neighbor-joining tree, whereas the interspecific variation among Branchinotogluma species was 8.19-22.4%. The results of this study contribute to biogeographic studies of B. segonzaci and the evolution of polynoid scale worms in chemosynthesis-based ecosystems.
Tristetraprolin regulates expression of VEGF and tumorigenesis in human colon cancer
Lee, Hyun Hee,Son, Young Joon,Lee, Won Hyeok,Park, Young Woo,Chae, Seoung Wan,Cho, Wha Ja,Kim, Young Min,Choi, Hye‐,Jeong,Choi, Dae Hwa,Jung, Seok Won,Min, Young Joo,Park, Soon Eun,Lee, Byung Ju Wiley Subscription Services, Inc., A Wiley Company 2010 International journal of cancer: Journal internati Vol.126 No.8
<P><B>Abstract</B></P><P>Tristetraprolin (TTP) is an AU‐rich element‐binding protein that regulates mRNA stability. Here, we report that TTP suppress the growth of human colon cancer cells both <I>in vivo</I> and <I>in vitro</I> by regulating of the expression of vascular endothelial growth factor (VEGF). TTP protein expression in human colonic tissues was markedly decreased in colonic adenocarcinoma compared with in normal mucosa and adenoma. VEGF expression was higher in colonic adenocarcinoma than in normal mucosa and adenoma. Specific inhibition of TTP expression by RNA‐interference increased the expression of VEGF in cultured human colon cancer cells, and TTP overexpression markedly decreased it. In addition, elevated expression of TTP decreased the expression level of luciferase linked to a 3′ terminal AU‐rich element (ARE) of VEGF mRNA. Colo320/TTP cells overexpressing TTP grew slowly <I>in vitro</I> and became tumors small in size when xenografted <I>s.c</I> into nude mice. These findings demonstrate that TTP acts as a negative regulator of VEGF gene expression in colon cancer cells, suggesting that it can be used as novel therapeutic agent to treat colon cancer.</P>