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>.

소 모색관련 유전자 MC1R 의 RCR - RFLP Marker 를 이용한 한우육 판별

정의룡,김우태,김연수,한상기 한국동물자원과학회 2000 한국축산학회지 Vol.42 No.4

The melanocortin 1 receptor(MClR) plays a central role in regulation of eumelanin(black/brown) and phaeomelanin(red/yellow) pigment synthesis within the mammalian melanocytes. Mutations within the gene encoding MC1R have been shown to explain coat colour variations within several species including cattle. This study was performed to develop the identification technique of Hanwoo meat using MC1R gene associated with the coat colors of cattle. Alleles of the MC1R locus were detected by PCR-RFLP analysis and genotype frequency and DNA sequences of MC1R gene were compared among cattle breeds. Genomic DNA was extracted from meat or blood samples of five breeds including Hanwoo(n=200), Holstein(n=100), Angus(n=20), Hereford(n=20) and Charolais(n=20). The MC1R gene was used to amplify 739bp and 173bp of the bovine E-locus corresponding to positions 228-966 and 318-490, respectively, using the two specific primers. The amplified products were digested with Bse118 I or Msp I and Aci I enzymes, and DNA fragments were separated by gel electrophoresis for RFLP genotype analysis. Six genotypes, E^D/E^D E^D/E^+, E^D/e, E^+/E^+,E^+/e and e/e, controlled by three alleles E^D, E^+ and e were observed in MC1 locus. When the amplified DNA product(739bp) was digested with Bse118 I enzyme, Hanwoo meat showed a single band of 739bp, whereas two fragments of 531bp and 208bp were detected in Holstein meat and Angus breed, respectively. Also, in the RFLP patterns using Msp I enzyme, Hanwoo meat produced two fragments of 535bp and 174bp, while three fragments of 328bp, 207bp and 174bp were observed in Holstein meat and Angus breeds, respectively. Therefore, breed-specific RFLP markers showing distinct differences between these breeds were found by PCR-RFLP analysis. When the amplified DNA product(173bp) was digested with Aci I enzyme to classify subtype of E allele, the E^D allele produced three fragments of 97, 68 and 8bp, while the E^+ and d alleles produced two fragments of 173 and 8bp according to the Aci I recognition sequence. Among the six genotypes, two genotypes of E^+/e and e/e were observed in Hanwoo and their frequencies were 0.07 and 0.93, respectively. However, the E^D/ED and E^D/e genotypes were present in Holstein and E^D/E^D, E^D/E^+ and E^D/e genotypes in Angus breeds. Therefore, the E^+/e and e/e genotypes observed in Hanwoo and E^D/E^D, E^D/E^+ and E^D/e genotypes detected only in Holstein and Angus breeds may be useful as breed-specific DNA markers for distinguishing between Hanwoo meat and Holstein and Angus meats. When comparing MC1R sequences among Hanwoo, Holstein and Angus, a Gly → Val amino acid change due to a single base(G) deletion at colon 104 was found in Hanwoo. Consequently, breed specific RFLP genotypes of MC1R gene related to bovine coat colors could be used as DNA markers for identification of Hanwoo meat from Holstein and Angus meats.

The effect of flavor content in e-liquids on e-cigarette emissions of carbonyl compounds

Qu, Yao,Kim, Ki-Hyun,Szulejko, Jan E. Elsevier 2018 Environmental research Vol.166 No.-

<P><B>Abstract</B></P> <P> <B>T</B>he effect of flavors on carbonyl compound (CC) emission factors (EF) from electronic cigarettes (ECs) vaping was investigated at the default vaping (voltage) setting in all experiments using a total of 21 lab-made e-liquid samples (five different types of retail flavorant bases: beverage/dessert/fruit/mint/tobacco). Each flavorant base was added to a separate unflavored base composed of a 1:1 mixture of propylene glycol/vegetable glycerol (PG/VG) at four levels (5/10/30/50% (v/v)). The e-liquid CC levels increased linearly with flavorant base content, 1.3–10.5 times (R<SUP>2</SUP>: 0.762–0.999). The vaping CC EFs increased linearly with flavorant base content (if ≥ 10%) from 1.0 to 92 times (R<SUP>2</SUP>: 0.431–0.998). For flavorant base content of 0%, 5%, and 10%, the EFs ranged from undetected to 0.11 μg puff<SUP>−1</SUP> (acetone). The 40-year cancer risk due to formaldehyde (70 kg EC user inhaling 5% flavorant base content e-liquid: 120 puffs day<SUP>−1</SUP>) is estimated to be 2.0E-06 (highest) compared to 1.0E-06 for the 1:1 PG:VG base. Most formaldehyde vaped from the fruit flavored e-liquid was the flavorant base. The CC concentrations in EC liquids (before vaping) were approximately linear with e-liquid flavorant base content. Retail e-liquid product information labels should be guided to provide a complete list of all ingredients, their concentrations, and carbonyl compound EFs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electronic cigarettes (e-cigarettes or ECs) are designed to deliver nicotine to a smoker. </LI> <LI> The flavorings in e-liquids were considered safe but raised concerns due to potential toxicity. </LI> <LI> In this study, we investigated the effects of flavor content on CC emissions from EC vaping. </LI> <LI> The CC amounts (before/during vaping) was estimated from the flavor content in the e-liquid. </LI> <LI> The effects of flavor content in e-liquids on vaping CC emissions warrant attention. </LI> </UL> </P>

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.

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.

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>

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.

NMR study of hydrogen exchange during the B-Z transition of a DNA duplex induced by the Zα domains of yatapoxvirus E3L

Lee, E.H.,Seo, Y.J.,Ahn, H.C.,Kang, Y.M.,Kim, H.E.,Lee, Y.M.,Choi, B.S.,Lee, J.H. North-Holland Pub ; Elsevier Science Ltd 2010 FEBS letters Vol.584 No.21

The Yaba-like disease viruses (YLDV) are members of the Yatapoxvirus family and have double-stranded DNA genomes. The E3L protein, which is essential for pathogenesis in the vaccinia virus, consists of two domains: an N-terminal Z-DNA binding domain and a C-terminal RNA binding domain. The crystal structure of the E3L orthologue of YLDV (yabZα<SUB>E3L</SUB>) bound to Z-DNA revealed that the overall structure of yabZα<SUB>E3L</SUB> and its interaction with Z-DNA are very similar to those of hZα<SUB>ADAR1</SUB>. Here we have performed NMR hydrogen exchange experiments on the complexes between yabZα<SUB>E3L</SUB> and d(CGCGCG)<SUB>2</SUB> with a variety of protein-to-DNA molar ratios. This study revealed that yabZα<SUB>E3L</SUB> could efficiently change the B-form helix of the d(CGCGCG)<SUB>2</SUB> to left-handed Z-DNA via the active-mono B-Z transition pathway like hZα<SUB>ADAR1</SUB>1.

PCR - SSCP 기법을 이용한 소 MC1R 유전자의 다형성 분석 및 한우육 감별

정의룡,김우태,김연수,한상기 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.1

The single-strand conformation polymorphism(SSCP) is a point mutation screening method based on changes in the secondary structure in a defined single-stranded DNA fragment caused by a change in sequence. This study was performed to develop the identification technique of Hanwoo meat using PCR-SSCP marker of MC1R gene associated with the coat colors of cattle. Hanwoo, Holstein and imported cattle breeds(Angus, Hereford and Charolais) were used for the detection of PCR-SSCP genotypes of MC1R gene. The specific primers were used to amplify a 138bp and a 390bp of the bovine E-locus(including point mutation) corresponding to positions 318-455 and 318-707, respectively, in the MC1R gene. For SSCP genotype analysis, the PCR products were denatured at 95℃ for 5min, loaded on a 12-15% nondenaturing polyacrylamide gel and detected by silver staining. When the PCR product of 138bp was separated by gel electrophoresis, two genotypes of E^+/e and e/e were detected only in Hanwoo meat, but E^D/E^D and E^D/e and E^D/E^D genotypes were observed in Holstein meat and Angus breed, respectively. Also, in the SSCP analysis using PCR product of 390bp, Hanwoo meat produced banding pattern of two fragments, while single fragment was observed in Holstein meat and Angus breed. Therefore, breed-specific SSCP markers showing distinct differences between Hanwoo and Holstein and Angus were found by PCR-SSCP analysis. This study shows that the PCR-SSCP technique is relatively simple, fast and a practical tool for determination of MC1R genotypes of cattle breeds when compared with PCR-RFLP method. Therefore, the PCR-SSCP markers of MC1R gene could be used as DNA markers for identification of Hanwoo meat from Holstein and Angus meats.

Cooperativity of E-cadherin and Smad4 Loss to Promote Diffuse-Type Gastric Adenocarcinoma and Metastasis

Park, Jun Won,Jang, Seok Hoon,Park, Dong Min,Lim, Na Jung,Deng, Chuxia,Kim, Dae Yong,Green, Jeffrey E.,Kim, Hark Kyun American Association for Cancer Research 2014 Molecular Cancer Research Vol.12 No.8

<P>Loss of E-cadherin (<I>CDH1</I>), Smad4, and p53 has been shown to play an integral role in gastric, intestinal, and breast cancer formation. Compound conditional knockout mice for Smad4, p53, and E-cadherin were generated to define and compare the roles of these genes in gastric, intestinal, and breast cancer development by crossing with <I>Pdx-1-Cre</I>, <I>Villin-Cre</I>, and <I>MMTV-Cre</I> transgenic mice. Interestingly, gastric adenocarcinoma was significantly more frequent in <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> mice than in <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1</I><SUP>+/+</SUP> mice, demonstrating that <I>Cdh1</I> heterozygosity accelerates the development and progression of gastric adenocarcinoma, in combination with loss of Smad4 and p53. <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> mice developed gastric adenocarcinomas without E-cadherin expression. However, intestinal and mammary adenocarcinomas with the same genetic background retained E-cadherin expression and were phenotypically similar to mice with both wild-type <I>Cdh1</I> alleles. Lung metastases were identified in <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> mice, but not in the other genotypes. Nuclear β-catenin accumulation was identified at the invasive tumor front of gastric adenocarcinomas arising in <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> mice. This phenotype was less prominent in mice with intact E-cadherin or Smad4, indicating that the inhibition of β-catenin signaling by E-cadherin or Smad4 downregulates signaling pathways involved in metastases in <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> mice. Knockdown of β-catenin significantly inhibited the migratory activity of <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> cell lines. Thus, loss of E-cadherin and Smad4 cooperates with p53 loss to promote the development and metastatic progression of gastric adenocarcinomas, with similarities to human gastric adenocarcinoma.</P><P><B>Implications:</B> This study demonstrates that inhibition of β-catenin is a converging node for the antimetastatic signaling pathways driven by E-cadherin and Smad4 in <I>Pdx-1-Cre;Smad4<SUP>F/F</SUP>;Trp53<SUP>F/F</SUP>;Cdh1<SUP>F</SUP></I><SUP>/+</SUP> mice, providing novel insights into mechanisms for gastric cancer metastasis. <I>Mol Cancer Res; 12(8); 1088–99. ©2014 AACR</I>.</P>