N₂/ CH₄가스비에 따른 Hydrogenated Amorphous Carbon Nitride 박막의 특성

장홍규(H. K. Jang),김근식(G. S. Kim),황보상우(S. W. Whangbo),이연승(Y. S. Lee),황정남(C. N. Whang),유영조(Y. Z. Yoo),김효근(H. G. Kim) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.3

DC saddle-field-plasma-enhanced chemical-vapor deposition(PECVD) 장치를 이용하여 상온에서 p-type Si (100) 기판위에 hydrogenated amorphous carbon nitride [a-C:H(N)]박막을 증착하였다. 원료가스인 CH₄과 N₂의 전체압력은 90 mTorr로 고정하고 N₂/CH₄비를 0에서 4까지 변화하면서 제작한 a-C:H(N) 박막의 미세 구조의 변화를 연구하였다. 진공조의 도달 진공도는 1×10^(-6) Torr이고, 본 실험시 CH₄+N₂가스의 유량은 5 sc㎝으로 고정하고 배기량을 조절하여 진공조의 가스 압력을 90 mTorr로 고정하였으며 기판에 200 V의 직류 bias 전압을 인가하였다. α-step과 X-ray photoelectron spectroscopy(XPS)를 이용한 분석결과 N₂/CH₄비가 0에서 0.5로 증가함에 따라 박막 두께는 4840 Å에서 2600 Å으로 급격히 감소하였으며, 박막내의 탄소에 대한 질소함유량(N/C비)는 N₂/CH₄비가 4일때 최대 0.25로 증가하는 것을 확인하였다. 또한 XPS 스펙트럼의 fitting 결과 N₂/CH₄비가 증가할수록 CN결합이 증가하였다. Fourier Transformation Infrared (FT-IR) 분석결과 N₂/CH₄비가 증가함에 따라 박막내의 C-H 결합은 감소하고, N-H, C≡N 결합은 증가하였다. Optical bandgap 측정 결 과 N₂/CH₄비가 0에서 4로 증가함에 따라 a-C:H(N)박막의 bandgap 에너지는 2.53 eV에서 2.3 eV로 감소하는 것을 확인하였다. Hydrogenated amorphous carbon nitride[a-C:H(N)] films were deposited on p-type Si(100) at room temperature with substrate bias voltage of 200 V by DC saddle-field plasma-enhanced chemical vapor deposition. Effects of the ratio of N₂to CH₄(N₂/CH₄), in the range of 0 and 4 on such properties as optical properties, microstucture, relative fraction of nitrogen and carbon, etc. of the films have been investigated. The thickness of the a-C:H(N) film was abruptly decreased with the addition of nitrogen, but at N₂/CH₄> 0.5, the thickness of the film gradually decreased with the increase of the N₂/CH₄. The ratio of N to C(N/C) of the films was saturated at 0.25 with the increase of N₂/CH₄. N-H, C≡N bonds of the films increased but C-H bond decreased with the increase of N₂/CH₄. Optical band gap energy of the film decreased from 2.53 eV deposited with pure methane to 2.3 eV at the ratio of N₂/CH₄=4.

Effects of Addition Level and Chemical Type of Propionate Precursors in Dicarboxylic Acid Pathway on Fermentation Characteristics and Methane Production by Rumen Microbes In vitro

Li, X.Z.,Yan, C.G.,Choi, S.H.,Long, R.J.,Jin, G.L.,Song, Man K. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.1

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

Intramolecular energy flow and bond dissociation in iodoacetylene and iododiacetylene

Ree,J.,Shin,H. K,Lee,C. S.,Kim,Y.H. 國立昌原大學校 基礎科學硏究所 1994 基礎科學硏究所論文集 Vol.6 No.-

Intermolecular and intramolecular energy flow and subsequent bond dissociation in collinear collisions Ⅰ-C≡C-H+Ar and Ⅰ-C≡C-C≡C-H+Ar have been studied by classical trajectory techniques over the collision energy range of 0 to 10 eV. When the molecule is initially in the ground state, the overall energy transfer in Ⅰ-C≡C-H+Ar is very small, but in Ⅰ-C≡C-C≡C-H+Ar it is large. The collisionally perturbed C-H bond stores a large amount of energy from translation for a brief period during the early stage of collision and transfers most of it to the inner region of the molecule, specifically to the low frequency C-I vibration. Thus the high-frequency vibration of the perturbed C-H bond during the collision plays a crucial role in determining the extent of intramolecular energy transfer and, in turn, C-I dissociation. But in nondissociative collisions, there is another series of the C-H vibration at the latter stage of collision. transferring energy back to translation. This study also considers collision-induced intramolecular energy flow in the molecule with an initially excited C-H bond. The relaxation of the low-lying C-H excitation is significantly weakened, thus becoming comparable to that of the triple bond, in which case the isolating effect of the adjacent C≡C bond is no longer important and intramolecular energy flow becomes efficient.

Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos)

H.C. Liu,J.F. Huang,S.R. Lee,H.L. Liu,C.H. Hsieh,C.W. Huang,M.C. Huang,C. Tai,J.P. Poivey,R. Rouvier,Y.S. Cheng 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie (h2 = 0.07±0.03) and M (h2 = 0.07±0.01), moderately low for Dm (h2 = 0.13±0.02), of medium values for H (h2 = 0.20±0.03) and F (h2 = 0.23±0.03). High and favourable genetic correlations existed between F and Dm (rg = 0.93), between F and H (rg = 0.97) and between Dm and H (rg = 0.90). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings’ feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

TmSR-C, scavenger receptor class C, plays a pivotal role in antifungal and antibacterial immunity in the coleopteran insect Tenebrio molitor

Kim, S.G.,Jo, Y.H.,Seong, J.H.,Park, K.B.,Noh, M.Y.,Cho, J.H.,Ko, H.J.,Kim, C.E.,Tindwa, H.,Patnaik, B.B.,Bang, I.S.,Lee, Y.S.,Han, Y.S. Pergamon Press ; Elsevier Science Ltd 2017 Insect biochemistry and molecular biology Vol.89 No.-

Scavenger receptors (SRs) constitute a family of membrane-bound receptors that bind to multiple ligands. The SR family of proteins is involved in removing cellular debris, oxidized low-density lipoproteins, and pathogens. Specifically, class C scavenger receptors (SR-C) have also been reported to be involved in phagocytosis of gram-positive and -negative bacteria in Drosophila and viruses in shrimp. However, reports are unavailable regarding the role of SR-C in antifungal immune mechanisms in insects. In this study, a full-length Tenebrio molitor SR-C (TmSR-C) sequence was obtained by 5'- and 3'-Rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The TmSR-C full-length cDNA comprised 1671 bp with 5'- and 3'-untranslated regions of 23- and 107-bp, respectively. TmSR-C encodes a putative protein of 556 amino acid residues that is constitutively expressed in all tissues of late instar larvae and 2-day-old adults, with the highest transcript levels observed in hemocytes of larvae and adults. TmSR-C mRNA showed a 2.5-fold and 3-fold increase at 24 and 6 h after infection with Candida albicans and β-glucan, respectively. Immunoassay with TmSR-C polyclonal antibody showed induction of the putative protein in the cytosols of hemocytes at 3 h after inoculation of C. albicans. RNA interference (RNAi)-based gene silencing and phagocytosis assays were used to understand the role of TmSR-C in antifungal immunity. Silencing of TmSR-C transcripts reduced the survivability of late instar larvae at 2 days post-inoculation of C. albicans, Escherichia coli, or Staphylococcus aureus. Furthermore, in TmSR-C-silenced larvae, there was a decline in the rate of microorganism phagocytosis. Taken together, results of this study suggest that TmSR-C plays a pivotal role in phagocytosing not only fungi but also gram-negative and -positive bacteria in T. molitor.

O-free polyacrylonitrile doping to improve the J_c(B) and H_c2 of MgB₂ wires

Hwang, S.M.,Sung, K.,Choi, J.H.,Kim, W.,Joo, J.,Lim, J.H.,Kim, C.J.,Park, Y.S.,Kim, D.H. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.20

We selected polyacrylonitrile (PAN, -[C<SUB>3</SUB>H<SUB>3</SUB>N]-) as an O-free organic dopant and fabricated C-doped MgB<SUB>2</SUB> wires by in situ and powder-in-tube techniques. 0-5 wt.% PAN powders were uniformly mixed with B powder using a liquid mixing method. The precursor powders were mixed with Mg powder, filled into Fe tubes, and then drawn into wires. Sintering was performed at 900<SUP>o</SUP>C for 1h in a flowing Ar gas. The PAN doping decreased the critical temperature (T<SUB>c</SUB>) and a-axis lattice parameter, but significantly improved the critical current density (J<SUB>c</SUB>) in high fields, upper critical field (H<SUB>c2</SUB>), and irreversibility field (H<SUB>irr</SUB>) performances. These results are attributed to the replacement of B sites with C by the PAN doping. Furthermore, as expected, the MgO amount did not increase as the doping content increased. The J<SUB>c</SUB> of the PAN-doped MgB<SUB>2</SUB> wires was more than one order of magnitude higher than that of the undoped MgB<SUB>2</SUB> wire at 5K and 6.6T (1.46-3.82kA/cm<SUP>2</SUP> vs. 0.11kA/cm<SUP>2</SUP>).

Interleukin-18, transforming growth factor-β, and vascular endothelial growth factor gene polymorphisms and susceptibility to primary glomerulonephritis

Choi, H.-J.,Cho, J.-H.,Kim, J.-C.,Seo, H.-J.,Hyun, S.-H.,Kim, G.-H.,Choi, J.-Y.,Choi, H.-J.,Ryu, H.-M.,Cho, J.-H.,Park, S.-H.,Kim, Y.-L.,Han, S.,Kim, C.-D. Blackwell Publishing Ltd 2010 Tissue antigens Vol.76 No.4

<P>Several studies have showed an association of gene polymorphisms with the development of glomerulonephritis (GN). We investigated the effects of gene polymorphisms on the development of GN by analyzing polymorphisms in the interleukin (IL)-18, transforming growth factor (TGF)-β, and vascular endothelial growth factor (VEGF) genes in Korean patients with primary GN. The study included 146 normal subjects (controls) and 100 patients diagnosed with primary GN by kidney biopsy. The gene polymorphisms A-607C and G-137C in <I>IL-18</I>, C-509T and T869C in <I>TGF-</I>β<I>1</I>, and C-2578A and C405G in <I>VEGF</I> were investigated in DNA extracted from peripheral blood. Significant differences were observed between the GN and control groups in the genotype and allele frequencies of A-607C <I>IL-18</I> and C405G <I>VEGF</I>. The frequencies of the <I>IL-18</I>−607CC genotype [<I>P</I> = 0.001, odds ratio (OR) = 2.473] and the <I>VEGF</I> 405GG genotype (<I>P</I> = 0.001, OR = 2.473) were significantly increased in the GN group. The combination of <I>IL-18</I>−607CC+ and <I>VEGF</I> 405GG+ genotypes had a higher risk for developing GN in comparison with the combination of <I>IL-18</I>−607CC− and <I>VEGF</I> 405GG− genotypes (<I>P</I> < 0.001, OR = 8.642). In the haplotype analysis of the <I>IL-18</I> gene, the CG haplotype was significantly more frequent in the GN group than the control group (61.5% <I>vs</I> 46.9%, <I>P</I> = 0.002). These results show that the −607CC genotype of the <I>IL-18</I> gene and the 405GG genotype of the <I>VEGF</I> gene are associated with susceptibility to and the development of primary GN.</P>

Gut-Specific Delivery of T-Helper 17 Cells Reduces Obesity and Insulin Resistance in Mice

Hong, C.P.,Park, A.,Yang, B.G.,Yun, C.H.,Kwak, M.J.,Lee, G.W.,Kim, J.H.,Jang, M.S.,Lee, E.J.,Jeun, E.J.,You, G.,Kim, K.S.,Choi, Y.,Park, J.H.,Hwang, D.,Im, S.H.,Kim, J.F.,Kim, Y.K.,Seoh, J.Y.,Surh, C. Elsevier North Holland [etc.] 2017 Gastroenterology Vol.152 No.8

<P>BACKGROUND & AIMS: Obesity and metabolic syndrome have been associated with alterations to the intestinal microbiota. However, few studies examined the effects of obesity on the intestinal immune system. We investigated changes in subsets of intestinal CD4(+) T-helper (T-H) cells with obesity and the effects of gut-tropic T(H)17 cells in mice on a high-fat diet (HFD). METHODS: We isolated immune cells from small intestine and adipose tissue of C57BL/6 mice fed a normal chow diet or a HFD for 10 weeks and analyzed the cells by flow cytometry. Mice fed a vitamin A-deficient HFD were compared with mice fed a vitamin A-sufficient HFD. Obese RAG1-deficient mice were given injections of only regulatory T cells or a combination of regulatory T cells and T(H)17 cells (wild type or deficient in integrin beta 7 subunit or interleukin 17 [IL17]). Mice were examined for weight gain, fat mass, fatty liver, glucose tolerance, and insulin resistance. Fecal samples were collected before and after T cell transfer and analyzed for microbiota composition by metagenomic DNA sequencing and quantitative polymerase chain reaction. RESULTS: Mice placed on a HFD became obese, which affected the distribution of small intestinal CD4(+) T-H cells. Intestinal tissues from obese mice had significant reductions in the proportion of T(H)17 cells but increased proportion of T(H)1 cells, compared with intestinal tissues from nonobese mice. Depletion of vitamin A in obese mice further reduced the proportion of T(H)17 cells in small intestine; this reduction correlated with more weight gain and worsening of glucose intolerance and insulin resistance. Adoptive transfer of in vitro-differentiated gut-tropic T(H)17 cells to obese mice reduced these metabolic defects, which required the integrin beta 7 subunit and IL17. Delivery of T(H)17 cells to intestines of mice led to expansion of commensal microbes associated with leanness. CONCLUSIONS: In mice, intestinal T(H)17 cells contribute to development of a microbiota that maintains metabolic homeostasis, via IL17. Gut-homing T(H)17 cells might be used to reduce metabolic disorders in obese individuals.</P>

Application of a wet oxidation method for the quantification of ³H and ¹⁴C in low-level radwastes

Ahn, H.J.,Song, B.C.,Sohn, S.C.,Lee, M.H.,Song, K.,Jee, K.Y. Pergamon Press ; Elsevier Science Ltd 2013 Applied radiation and isotopes Vol.81 No.-

Wet oxidation methods are utilized to separate and quantify <SUP>3</SUP>H and <SUP>14</SUP>C radionuclides in inorganic and organic radwastes generated at nuclear facilities. Because <SUP>3</SUP>H and <SUP>14</SUP>C are pure beta emitters with half-lives of 12.3 and 5,730 years, respectively, these radionuclides should be chemically separated from other radionuclides present in radwastes for accurate quantification. In particular, a collection technique for <SUP>14</SUP>C radionuclide in radwastes is needed because it is converted into <SUP>14</SUP>CO<SUB>2</SUB> gas by an oxidation reaction. To confirm the recoveries of <SUP>3</SUP>H and <SUP>14</SUP>C, various standard radioactive sources were used to verify the proposed method. Because the majority of <SUP>3</SUP>H radionuclides are distributed in tritiated water (HTO), only tritiated water was used as a standard for <SUP>3</SUP>H radionuclides. Additionally, <SUP>14</SUP>C-labeled methanol (<SUP>14</SUP>CH<SUB>3</SUB>OH), lauric acid (<SUP>14</SUP>CH<SUB>3</SUB>(CH<SUB>2</SUB>)<SUB>10</SUB>COOH), sodium bicarbonate (NaH<SUP>14</SUP>CO<SUB>3</SUB>), and toluene (C<SUB>6</SUB>H<SUB>5</SUB><SUP>14</SUP>CH<SUB>3</SUB>) were used as <SUP>14</SUP>C standards. The compounds were oxidized with chemical oxidants and then separated. The individual species were mixed with a scintillation cocktail and counted using a liquid scintillation counter. The recoveries of <SUP>14</SUP>C and <SUP>3</SUP>H were 82-97% and 98%, respectively. The wet oxidation method will be applied to RI wastes for clearance.

Comparison of the [$^2H_5$]Phenylalanine Model with the [1-$^{13}C$]Leucine Method to Determine Whole Body Protein Synthesis and Degradation in Sheep Fed at Two Levels

Al-Mamun, M.,Ito, C.,Fujita, T.,Sano, H.,Sato, A. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.10

The [$^2H_5$]phenylalanine model was compared with the [1-$^{13}C$]leucine method to determine whole body protein synthesis (WBPS) and degradation (WBPD) in sheep fed at two levels. The animals were fed either 103 (M-diet) or 151 (H-diet) kcal $ME/kg^{0.75}/day$ once daily in a crossover design for 21 days each. The isotope dilutions were simultaneously conducted as a primed-continuous infusion of [$^2H_5$]phenylalanine, [$^2H_2$]tyrosine and [1-$^{13}C$]leucine on each dietary treatment. The WBPS and WBPD calculated from the [$^2H_5$]phenylalanine model were lower (p = 0.009 and p = 0.003, respectively) than those calculated from the [1-$^{13}C$]leucine method. The WBPS tended to be higher (p = 0.08) and WBPD was numerically higher (p = 0.33) for H-diet than M-diet in the [$^2H_5$]phenylalanine model, whereas the WBPS was numerically higher (p = 0.37) for H-diet and WBPS remained similar (p = 0.79) between diets in the [1-$^{13}C$]leucine method. However, the absolute values and the directions of WBPS as well as WBPD from M-diet to H-diet were comparable between the [$^2H_5$]phenylalanine model and [1-$^{13}C$]leucine method. Moreover, the values vary depending on the use of the respective amino acid contents in the carcass protein when calculating WBPS and WBPD. Therefore, it is concluded that the [$^2H_5$]phenylalanine model could be used as an alternative to the [1-$^{13}C$]leucine method for the determination of WBPS and WBPD in sheep.