Characterization of Interface States in MOS Systems by Using Photonic High-Frequency Capacitance-Voltage Responses

S.J.Song,H.T.Kim,S.S.Chi,M.S.Kim,W.S.Chang,S.D.Cho,H.T.Shin,T.E.Kim,H.J.Kang,D.J.Kim,D.M.Kim 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.41 No.6

Based on the photonic high-frequency capacitance-voltage response of Metal-Oxide-Semiconductor capacitors, we report an improved characterization method for the analyzing of interface states in MOS systems. An optical source with a photonic energy $E_{ph}$ = 0.943 eV ($\lambda$ = 1314.5 nm) is employed for photonic deep-depletion (fast sweep rate) high-frequency Capacitance-Voltage (photonic DD HF-CV) characterization of interface states distributed in the photo-responsive energy band. Using the photonic DD HF-CV characterization, we obtained a U-shaped distribution of $D_{it}$ over ($E_V + E_g/2 - q\phi_f) < E_t < (E_V + E_g/2 - q\phi_f + q\phi_S$) for N-type Metal-Oxide-Semiconductor capacitors and ($E_C - E_g/2 - q\phi_f + q\phi_S) < E_t < (E_C - E_g/2 - q\phi_f$) for P-type Metal-Oxide-Semiconductor capacitors.

Production of (S)-3-hydroxybutyrate by metabolically engineered Saccharomyces cerevisiae

Yun, E.J.,Kwak, S.,Kim, S.R.,Park, Y.C.,Jin, Y.S.,Kim, K.H. Elsevier Science Publishers 2015 Journal of biotechnology Vol.209 No.-

(S)-3-Hydroxybutyrate (S-3HB) can be used as a precursor for the synthesis of biodegradable polymers such as polyhydroxyalkanoate and stereo-specific fine chemicals such as antibiotics, pheromones, and drugs. For the production of S-3HB in yeast, the biosynthetic pathway of S-3HB from acetyl-CoA, consisting of the three enzymes, acetyl-CoA C-acetyltransferase (ACCT), acetoacetyl-CoA reductase (ACR), and 3-hydroxybutyryl-CoA thioesterase (HBT), was introduced into Saccharomyces cerevisiae. An engineered yeast strain overexpressing ERG10, hbd, and tesB genes not only exhibited enzyme activities of AACT, ACR, and HBT, but also produced S-3HB from ethanol. In order to increase the titer of S-3HB, a fed-batch fermentation based on pulse feeding of ethanol as a carbon source was performed, and a final S-3HB titer of 12.0g/L was achieved. This is the first report on the production of 3HB by engineered yeast, utilizing ethanol as the carbon source, suggesting that the industrially preferred S. cerevisiae can be a promising host for producing S-3HB.

Association of Extracellular Cleavage of E-Cadherin Mediated by MMP-7 with HGF-Induced in vitro Invasion in Human Stomach Cancer Cells

Lee, K.H.,Choi, E.Y.,Hyun, M.S.,Jang, B.I.,Kim, T.N.,Kim, S.W.,Song, S.K.,Kim, J.H.,Kim, J.-R. S. Karger AG 2007 European surgical research Vol.39 No.4

<P><I>Background:</I> Proteolytic shedding of the ectodomain of a variety of transmembrane proteins, including cell-to-cell adhesion molecules, has been observed in solid cancers. We have investigated whether extracellular cleavage of E-cadherin mediated by matrix metalloproteinase-7 (MMP-7) is involved in hepatocyte growth factor (HGF) induced in vitro invasion in stomach cancer cells. <I>Methods:</I> The effects of HGF on the expression of E-cadherin/β-catenin and MMP-7 at both the protein and mRNA levels were assessed in stomach cancer cells, NUGC-3 and MKN-28, and in cells in which the expression of MMP-7 was downregulated by transfection with a MMP-7 short hairpin RNA plasmid. <I>Results:</I> Treatment with HGF increased the extracellular cleavage of E-cadherin and the release of MMP-7 and reduced the level of E-cadherin in a dose- and time-dependent manner. HGF treatment repressed the phosphorylation of β-catenin in a Triton-soluble fraction, but enhanced this phosphorylation in a Triton-insoluble fraction. The association of E-cadherin with β-catenin was decreased by HGF treatment in the Triton-soluble fraction. In addition, treatment of MMP-7 short hairpin RNA transfected NUGC-3 cells with HGF resulted in no extracellular cleavage of E-cadherin and also decreased the in vitro cell invasion. <I>Conclusions:</I> These results suggest that incubation with HGF mediated the release of MMP-7, resulting in extracellular cleavage of E-cadherin from stomach cancer cells. This might be a key mechanism in HGF-induced in vitro invasion and metastasis.</P><P>Copyright © 2007 S. Karger AG, Basel</P>

단세포군 항체를 이용한 Shigella serotyping serum 개발(Ⅱ) : S. flexneri type Ⅰ,Ⅱ & type Ⅰ:6, group 6

정의범,이영희,김순남,박강수,이명숙,성원근,김종욱,홍승의,박정우 국립보건연구원 1994 국립보건원보 Vol.31 No.1

Inflammatory lipid sphingosine-1-phosphate upregulates C-reactive protein via C/EBPβ and potentiates breast cancer progression

Kim, E-S,Cha, Y,Ham, M,Jung, J,Kim, S G,Hwang, S,Kleemann, R,Moon, A Macmillan Publishers Limited 2014 Oncogene Vol.33 No.27

A crucial role of the inflammatory lipid sphingosine-1-phosphate (S1P) in breast cancer aggressiveness has been reported. Recent clinical studies have suggested that C-reactive protein (CRP) has a role in breast cancer development. However, limited information is available on the molecular basis for the expression of CRP and its functional significance in breast cell invasion. The present study aimed to elucidate the molecular link between S1P and CRP during the invasive process of breast epithelial cells. This is the first report showing that transcription of CRP was markedly activated by S1P in breast cells. Our data suggest that not only S1P treatment but also the endogenously produced S1P may upregulate CRP in breast carcinoma cells. Transcription factors CCAAT/enhancer-binding protein beta and c-fos were required for S1P-induced CRP expression. Coupling of S1P<SUB>3</SUB> to heterotrimeric G<SUB>αq</SUB> triggered the expression of CRP, utilizing signaling pathways involving reactive oxygen species (ROS), Ca<SUP>2+</SUP> and extracellular signal-related kinases (ERKs). S1P-induced CRP expression was crucial for the transcriptional activation of matrix metalloproteinase-9 through ERKs, ROS and c-fos, leading to breast cell invasion. Using a xenograft mice tumor model, we demonstrated that S1P induced CRP expression both in vitro and in vivo. Taken together, our findings have revealed a molecular basis for S1P-induced transcriptional activation of CRP and its functional significance in the acquisition of the invasive phenotype of human breast epithelial cells under inflammatory conditions. Our findings may provide useful information on the identification of useful therapeutic targets for inflammatory breast cancer.

화력발전소의 대기오염물질 배출계수 산정 연구

김대곤,엄윤성,홍지형,이석조,석광설,이대균,이은정,방선애 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.3

The main purpose of this study was to characterize the air pollutants emission factors in electric power plant (EPP) using fossil fuels. The electric power plant is a major air pollution source, thus knowing the emission characteristics of electric power plant is very important to develop a control strategy. The major air pollutants of concern from EPP stacks are particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO) and heavy metals. Throughout the study. the following results arc estimated: - PM : 8.671E-05∼8.724E+01 PM emission (kg) per fuel burned (ton) - SOx: 4.749E-04∼7.877E+01 SOx emission (kg) per fuel burned (ton) - NOx : 1.578E-02∼9.857E+00 NOx emission (kg) per fuel burned (ton) - CO : 3.800E-04∼1.291E+00 CO emission (kg) per fuel burned (ton) - Hg : 1.220E+01∼3.108E+02 Hg emission (mg) per fuel burned (ton) From the statistical analysis by Wilcoxon signed ranks test between the emission factors of ours and U.S. EPA's. we can yielded that: p > 0.05.

Optical subthreshold current method for extracting the interface states in MOS systems

Kim, M.S.,Nam, I.C.,Kim, H.T.,Shin, H.T.,Kim, T.E.,Park, H.S.,Kim, K.S.,Kim, K.H.,Choi, J.B.,Min, K.S.,Kim, D.J.,Kang, D.W.,Kim, D.M. IEEE 2004 IEEE electron device letters Vol.25 No.2

Optical subthreshold current method (OSCM) is proposed for characterizing the interface states in MOS systems using the current-voltage characteristics under a photonic excitation. An optical source with a subbandgap (E<SUB>ph</SUB>>E<SUB>g</SUB>) photonic energy (E<SUB>ph</SUB>=0.943 eV, P<SUB>opt</SUB>=+5 dBm), which is less than the silicon bandgap (E<SUB>g</SUB>=1.12;eV), is employed for the optical subthreshold current characterization of interface states in the photoresponsive energy band. We applied the OSCM method under a subbandgap photonic excitation to MOS systems with a poly-Si gate and verified a U-shaped distribution of interface trap density D<SUB>it</SUB>=10<SUP>10</SUP>∼10<SUP>12</SUP> eV<SUP>-1</SUP>cm<SUP>-2</SUP> for n- and p-type MOSFETs with W/L=30 μm/1.2 μm.

Association and functional relevance of E237G, a polymorphism of the high-affinity immunoglobulin E-receptor β chain gene, to airway hyper-responsiveness

Kim, Y.-K.,Park, H.-W.,Yang, J.-S.,Oh, S.-Y.,Chang, Y.-S.,Shin, E.-S.,Lee, J.-E.,Kim, S.,Gho, Y. S.,Cho, S.-H.,Min, K.-U.,Kim, Y.-Y. Blackwell Scientific Publications 2007 Clinical and experimental allergy Vol.37 No.4

<P>Summary</P><P>Background</P><P>The hyper-sensitivity reaction of IgE, with its high-affinity receptors (FcϵRI), is central to the phenomenon of atopic diseases.</P><P>Objective</P><P>To evaluate the genetic effects of non-synonymous single-nucleotide polymorphisms (SNPs) of FcϵRI on intermediate phenotypes of asthma, i.e. atopy and airway hyper-responsiveness (AHR), in the Korean general population.</P><P>Subjects and methods</P><P>Atopy and AHR were evaluated in a cohort of 2055 subjects, aged 10–18 years, using skin prick tests (SPTs) for common aeroallergens and total serum IgE and methacholine bronchial provocation tests. All FcϵRI-α, FcϵRI-β, and FcϵRI-γ gene exons of 24 healthy subjects were sequenced to locate informative non-synonymous SNPs (minor allele frequency >2%). Informative SNPs were then scored, using the high-throughput single base extension method. Relative risk (RR) was determined by multiple logistic regression analysis, after adjusting for confounding factors. The functional relevance of non-synonymous SNPs was analysed using the sorting intolerant from tolerant (SIFT) program.</P><P>Results</P><P>The SNP search found only one informative non-synonymous SNP in FcϵRI-β: E237G (minor allele frequency=0.21). The positive rate of AHR was lower among subjects with the 237<SUP>*</SUP>E allele than among those with 237<SUP>*</SUP>G [RR (95% confidence interval)=0.41 (0.19–0.89); <I>P</I>=0.01]. However, the E237G substitution was not associated with either a positive SPT response or total serum IgE levels. Sequence evolution analysis predicted that the E237G variation is an intolerant amino acid substitution, with functional importance.</P><P>Conclusion</P><P>In the Korean general population, AHR is significantly associated with the E237G polymorphism of FcϵRI-β, which results in an intolerant amino acid substitution.</P>

Interpretation of cryogenic-temperature Charpy fracture initiation and propagation energies by microstructural evolution occurring during dynamic compressive test of austenitic Fe-(0.4,1.0)C-18Mn steels

Kim, H.,Park, J.,Jung, J.E.,Sohn, S.S.,Lee, S. Elsevier Sequoia 2015 Materials science & engineering. properties, micro Vol.641 No.-

In the present study, Charpy impact energy (E<SUB>T</SUB>) composed of fracture initiation energy (E<SUB>I</SUB>) and propagation energy (E<SUB>P</SUB>) of austenitic Fe-(0.4,1.0)C-18Mn steels was evaluated in the temperature range from room to cryogenic temperatures by an instrumented Charpy impact tester, and was interpreted by microstructural evolution of dynamically compressed specimens. In the 1.0C-18Mn steel, the E<SUB>I</SUB> and E<SUB>P</SUB> decreased slightly with decreasing temperature, but the E<SUB>P</SUB>/E<SUB>T</SUB> ratio was kept to be about 0.5. In the 0.4C-18Mn steel, the E<SUB>I</SUB> remained almost constant or slightly decreased with decreasing temperature, while the E<SUB>P</SUB>/E<SUB>T</SUB> ratio steadily decreased, thereby leading to the lower (about 30%) cryogenic-temperature E<SUB>T</SUB> than that of the 1.0C-18Mn steel. Under the dynamic compressive loading, a considerable number of ε-martensites were formed in the 0.4C-18Mn steel, whereas they were not found in the 1.0C-18Mn steel, and their volume fractions increased steadily with decreasing temperature. This γ→ε-martensite transformation was attributed to the decrease in stacking fault energy, and resulted in the very low E<SUB>P</SUB> and resultant E<SUB>T</SUB>.

DMNQ S-64 Induces Apoptosis via Caspase Activation and Cyclooxygenase-2 Inhibition in Human Nonsmall Lung Cancer Cells

LIM, E.-S.,RHEE, Y.-H.,PARK, M.-K.,SHIM, B.-S.,AHN, K.-S.,KANG, H.,YOO, H.-S.,KIM, S.-H. Wiley (Blackwell Publishing) 2007 Annals of the New York Academy of Sciences Vol.1095 No.1

<P>Shikonin has been reported to induce apoptosis and inhibit angiogenesis in vivo and in vitro. 6-(1-propoxyiminoalkyl)-5,8-dimethoxyoxy 1,4-naphtoquinone S-64 (DMNQ S-64) was synthesized as a shikonin derivative. In this article, the underlying apoptotic mechanism of DMNQ S-64 was examined. DMNQ S-64 exerted cytotoxicity against A549 lung carcinoma cells with IC(50) of 27.3 microM. Apoptotic bodies were observed in DMNQ S-64-treated A549 cells by 4'-6-diamidino-2-phenylindole (DAPI) staining assay. DMNQ S-64 also increased sub-G1 DNA portion in a concentration-dependent manner by flow cytometric analysis. Western blotting has revealed that DMNQ S-64 effectively activates the expression of caspase 8, 9, and 3, cleaves poly (ADP-ribose) polymerase, and increases the ratio of Bax/Bcl-2. Furthermore, cytochrome c was released in a concentration-dependent manner by DMNQ S-64. Similarly, DMNQ S-64 significantly increased caspase 3 activity by enzyme-linked immunosorbent assay (ELISA). It also significantly inhibited the level of prostaglandin E2 (PGE(2)) by ELISA and downregulated the expression of cyclooxygenase-2 (COX-2) in a concentration-dependent manner. Taken together, DMNQ S-64 may exhibit cytotoxicity against A549 cells via caspase activation and COX-2 inhibition.</P>