성장단계별 농후사료 (濃厚飼料) 급여수준이 한우 육성빈우의 (育成牝牛) 체중변화 및 번식능력에 미치는 영향

강수원(S . W . Kang),장선식(S . S . Jang),임석기(S . K . Im),정창화(C . H . Chung),신기준(K . J . Shin) 한국영양사료학회 1996 韓國營養飼料學會誌 Vol.20 No.2

성장단계별 농후사료 (濃厚飼料) 급여수준이 한우 육성비육우의 (育成肥育牛) 사료효율 , 산육능력 및 육질에 미치는 영향

강수원(S . W . Kang),장선식(S . S . Jang),정연후(Y . H . Chung),신기준(K . J . Shin),손용석(Y . S . Son) 한국영양사료학회 1995 韓國營養飼料學會誌 Vol.19 No.6

선택적 촉매 산화 반응에 의한 황화수소의 제거 1 . 촉매의 개발

천승우,박대원,우희철,홍성수,정종식 ( S . W . Chun,D . W . Park,H . C . Woo,S . S . Hong,J . S . Chung ) 한국공업화학회 1995 공업화학 Vol.6 No.5

본 연구는 H₂S를 산소와의 직접 산화 반응을 통해 원소 황의 형태로 제거하는 반응에서 고농도의 H₂S를 처리할 수 있는 촉매의 개발에 관한 것이다. 최적의 촉매를 개발하기 위해 각 담체와 금속 산화물에 대한 반응성 실험을 실시하였다. 실험 결과 담체로는 Al₂O₃, TiO₂, ZrO₂ 등이 금속 산화물로서는 Fe₂O₃, V₂O_5, SnO₂, Cr₂O₃ 등이 좋은 활성을 보였다. 반응물 중의 산소의 분압 영향과 반응물에 포함되어질 수 있는 물의 영향에 대해서 관찰한 결과 산소의 분압이 높을수록 전화율은 증가하나 황 선택도는 급격히 감소하는 경향을 보였고, 10vol.%의 물을 반응물에 첨가한 경우 전화율과 황 선택도가 동시에 감소하는 경향을 보였다. In this study, development of catalysts far the direct oxidation of hydrogen sulfide to elemental sulfur, specially for the treatment of high concentrantion of H₂S, was investigated. To find out optimum catalysts, a screenig test for various supports and metal oxides was carried out. Among the supports tested, Al₂O₃, TiO₂ and ZrO₂ showed good catalytic activity. Fe₂O₃, V₂O_5, SnO₂ and Cr₂O₃ have been considered to be active metal oxides. The study on the effects of oxygen partial pressure revealed that the conversion of H₂S increased with increasing the ratio of O₂/H₂S, but the selectivity to sulfur was drasctically decreased. Bath of the conversion of H₂S and the selectivity to sulfur were decreased when 10 vol.% of water was added to the mixture of H₂S and oxygen.

Enhanced ammonia dehydrogenation over Ru/La(x)-Al₂O₃ (x=0-50 mol%): Structural and electronic effects of La doping

Chung, D.B.,Kim, H.Y.,Jeon, M.,Lee, D.H.,Park, H.S.,Choi, S.H.,Nam, S.W.,Jang, S.C.,Park, J.H.,Lee, K.Y.,Yoon, C.W. Pergamon Press ; Elsevier Science Ltd 2017 International journal of hydrogen energy Vol.42 No.3

<P>Ru (1.0 wt% loaded)-based catalysts supported on La(x)-Al2O3 (x = 0,1, 5,10, and 50 mol%) were synthesized and characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) measurement, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and temperature programmed reduction (TPR). The as-prepared La(x)-Al2O3 materials were found to have increased amounts of the LaAlO3 phase as the La doping level (x) increased from 0 to 50 mol%. In addition to metal-to support interactions between Ru and Al2O3, the newly formed LaAlO3 phase in the Ru catalysts was proposed to interact strongly with Ru active sites based on the XRD, H-2-TPR and XPS results. The Ru/La(x)-Al2O3 catalysts were active for the dehydrogenation of ammonia, and among them, the Ru/La(10)-Al2O3 and Ru/La(50)-Al2O3 (or Ru/LaAlO3) catalysts exhibited superior performance with >96% conversions of ammonia at 550 degrees C. When an increased Ru content (2.0 wt%) was impregnated onto La(10)-Al2O3, the dehydrogenation activity was significantly improved with nearly 100% conversion (>95%) of ammonia at 500 degrees C. This catalyst further displayed an enhanced thermal stability towards ammonia decomposition with the GHSV(NH3) of 10,000 mL/g(cat)h at 550 degrees C for >120 h. The incorporated element La is thought to play an important role in enhancing metal-support interaction, ultimately facilitating ammonia dehydrogenation even at low temperatures. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>

Participation of Embryonic Genotype in the Pregnancy Block Phenomenon in Mice

Chung, H.J.,Seong, H.H.,Chang, Y.M.,Choi, J.H.,Woo, J.H.,Lee, Y.Y.,Im, S.K.,Lee, H.T.,Chang, W.K 한국수정란이식학회 2002 한국수정란이식학회 학술대회 Vol.2002 No.1

Pregnancy block by male pheromones in mice differs in incidence depending on the combination of strains. Female mice of BALB/cA strain mated with BALB/cA males show a 100% pregnancy block when exposed to males of inbred strain DDK shortly after copulation (Chung et al., Biol Reprod 1997). In the present study, BALB/cA females mated with the males of other strains (CBA/J, C3H/HeN, C57BL/6Cr, and IXBL) showed higher pregnancy rates (66.6-87.5%) even when they were exposed to DDK males. In the pharmacological induction of pregnancy block with dopamine agonist (Bromocriptine, 4mg/kg BW), BALB/cA females mated with BALB/cA males showed a 100% pregnancy block. In contrast, BALB/cA females mated with CBA/J, C3H/HeN, and C57BL/6Cr males showed higher pregnancy rates (40-70%). These results suggest that the better pregnancy rate of BALB/cA females mated with alien males may be due to the stronger viability of F 1 embryos. This interpretation was confirmed by an embryo transfer experiment in which a higher implantation rate was observed when BALB/cA embryos grown in BALB/cA females exposed to BALB/cA males were transferred into recipient BALB/cA females exposed to DDK males. These results suggest that the embryonic genotype or viability of the embryo is one factor contributing to the occurrence of pregnancy block by male pheromones in mice.

Vertical distribution of 137Cs 90Sr activities in the soils of Korea

Cha, H.J.,D.W. Park,H.K Park,M.J. Kang,W.R. Lee,G.S. Choi,Y.H. Cho,K.H. Chung,H.P. Lee,H.S. Shin,C.W. Lee 대한방사선방어학회 2004 방사선방어학회지 Vol.29 No.3

한우 육성빈우 (育成牝牛) 의 에너지와 단백질요구량 추정 1 . 대사시험에 의한 한우 육성빈우의 에너지와 단백질 요구량 결정

정연후(Y . H . Chung),이상철(S . C . Lee),강수원(S . W . Kang),정정수(C . S . Chung),정천용(C . Y . Chung) 한국축산학회 1992 한국축산학회지 Vol.34 No.5

Metabolism trial was carried out to estimate the energy and protein requirements for Korean native heifers. Nine heifer calves weighing about 150㎏ were randomly assigned into three target daily gains (0.2㎏, T₁; 0.6㎏, T₂; 0.8㎏, T₃) with interval of BW 50㎏ through BW 350㎏, aiming to estimate the energy and protein requirements. The amount of nutrient to be fed was based on NRC requirements (1984), and the ration consisted of hay, rice straw and grass silage as roughage source, and concentrate mixture. Average daily gains across body weight classes were 0.30(T₁), 0.62(T₂) and 0.67㎏(T₃), respectively. Except for crude fiber, digestibilities and nutritive values of experimental ration were increased with the increase of daily gain. As expected, nitrogen intake was significantly(P$lt;0.05) increased with the increase of daily gain, but there were no differences in digestible nitrogen intake and nitrogen retention between T₂ and T₃ group. Based on pooled data of body weight classes, nitrogen(N) and digestible nitrogen(DN) requirements were estimated as follows; N requirement(g/W^0.75/day) = 0.98+1.25DG-0.44DG² (R²=0.42**), DN requirement(g/W^0.75/day) = 0.40+1.19DG-0.24DG² (R²=0.49**) Metabolizable energy intake, heat production and energy retention tended to increase with the increase of daily gains, not with body weight, although there was no difference between T₂ and T₃ group. Energy losses expressed as % of gross energy(GE) intake was higest from feces(42.8%), followed by heat production(42.3%), and lowest from urine(2.0%). Total digestible nutrient(TDN), DE and ME requirements were as follows; TDN requirement(g/W^0.75/day) = 28.13+60.40DG-14.03DG² (R²=0.48**), DE requirement(㎉/W^0.75/day) = 134.34+ 220.59DG-71.90DG² (R²=0.54**), ME requirement(㎉/W^0.75/day) = 116.98+171.32DG-35.73DG²(R²=0.54**). Total digestible nutrient, DE and ME requirements for maintenance were 28.13g, 134.3㎉ and 116.98 ㎉/W^0.75/day, respectively. The estimated NEm requirement from the relationship between ME intake and heat production was 76.5㎉/W^0.75/day.

1987년 한국에서 발생한 렙토스피라병의 혈청역학적 조사

이증훈,박영수,이우곤,김석용,정선식,우준희,박성광,박경희,송영욱,김선영,기정일,최두혁,강성귀,김주완,최강원,김우열,최명식,최인학,장우현,윤성열 대한감염학회 1988 감염 Vol.20 No.3

Human leptospirosis was an unfamiliar disease in Korea until 1984 that outbreak of leptospirosis occurred among farmers and soldiers after field works for harvesting rice. During that time, Lee and Jo confirmed the first Korean cases of leptospirosis by serological test, isolation of causative agent and autopy findings. Afterward several outbreaks occurred also during autumn especially after flood in every years and some characterisitcs of leptospirosis in Korea such as clinical manifestations, serotypes and seroepidemiological features has been revealed by many investigators. Because of the major mode of transmission between rodents and human is by direct contact with leptospiral urine of rodents or contaminated soil by the urine, leptospirosis in Korea has been primarily a disease of person in occupations heavily exposed to contaminated soil or infected urine such as farmer, army and etc. Therefore it seems that leptospirosis is one of the main communicable diseases to be controlled urgently in Korea, for an agricultural people account for almost half of total Korean people. For clarifying the seroepidemiological patterns of human leptospirosis in Korea by sex, month region and main reacting serovars of L. interrogans among acute febrile disease occurred in 1987, 1,773 patient's sers with acute febrile episodes were tested by microagglutination test using 19 representative strains of leptospiral serogroup as antigen. All of those sera were collected from 10 collaborative clinics located in Kyunggi, Kangwon, Chungbuk, Chungnam, Chonbuk, Chonnam province and Seoul. The results wee summerized as follows. 1) Among 1,773 sera of patients with acute febrile episodes, 219 (12.4%) were seropositive to L. interrogans, 487(27.5%) to R. tsutsugamushi, 241(13.6%) to R.typhi and 160(90.0%) to Hantaan virus. 2) Among seropositives to L.interrogans, the male outnumbered the female, 65% and 35%. 3) For age distribution, 26.9% of seropositives to L.interrogans were fifties, 19.6% were forties, 9.1% were sixties, 5.9% were thirties and 4.1% were twenties. 4) Eighty three percent of seropositives had occurred between September and October in 1987 with a peak in September. 5) Main leptospiral serovars reactive to patient's sera were Icterohaemorrhagiae(54.3%), Canicola(31.0%), CH-48(13.2%), Tarassovi(0.9%)and Cynopteri(0.5%). 6) For regional distribution, 65.8% of seropositives to L.interrogans were residents from Chonbuk, 12.3% were Chonnam, 7.3% were Chungnam, 5.5% were Kyunggi and 1.4% were Kangwon.

Heme oxygenase-1 mediates nicotine- and lipopolysaccharide-induced expression of cyclooxygenase-2 and inducible nitric oxide synthase in human periodontal ligament cells

Pi, S.-H.,Jeong, G.-S.,Oh, H.-W.,Kim, Y.-S.,Pae, H.-O.,Chung, H.-T.,Lee, S.-K.,Kim, E.-C. Blackwell Publishing Ltd 2010 Journal of periodontal research Vol.45 No.2

<P><I>Pi S-H, Jeong G-S, Oh H-W, Kim Y-S, Pae H-O, Chung H-T, Lee S-K, Kim E-C. Heme oxygenase-1 mediates nicotine- and lipopolysaccharide-induced expression of cyclooxygenase-2 and inducible nitric oxide synthase in human periodontal ligament cells. J Periodont Res 2010; 45: 177–183. © 2010 John Wiley & Sons A/S</I></P><P>Background and Objective: </P><P>Although heme oxygenase-1 (HO-1) plays a key role in inflammation, its anti-inflammatory effects and mechanism of action in periodontitis are still unknown. This study aimed to identify the effects of HO-1 on the proinflammatory mediators activated by nicotine and lipopolysaccharide (LPS) stimulation in human periodontal ligament (PDL) cells.</P><P>Material and Methods: </P><P>The production of nitric oxide (NO) and prostaglandin E<SUB>2</SUB> (PGE<SUB>2</SUB>) was evaluated using Griess reagent and an enzyme immunoassay, respectively. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and HO-1 proteins was evaluated by Western blot analysis.</P><P>Results: </P><P>Lipopolysaccharide and nicotine synergistically induced the production of NO and PGE<SUB>2</SUB> and increased the protein expression of iNOS, COX-2 and HO-1. Treatment with an HO-1 inhibitor and HO-1 small interfering RNAs blocked the LPS- and nicotine-stimulated NO and PGE<SUB>2</SUB> release as well as the expression of iNOS and COX-2.</P><P>Conclusion: </P><P>Our data suggest that the nicotine- and LPS-induced inflammatory effects on PDL cells may act through a novel mechanism involving the action of HO-1. Thus, HO-1 may provide a potential therapeutic target for the treatment of periodontal disease associated with smoking and dental plaque.</P>

선택적 촉매 산화 반응에 의한 황화 수소의 제거 Ⅱ . TiO2 / SiO2 촉매 상에서 황화 수소의 선택적 산화 반응

천승우,박대원,우희철,홍성수,정종식 ( S . W . Chun,D . W . Park,H . C . Woo,S . S . Hong,J . S . Chung ) 한국공업화학회 1996 공업화학 Vol.7 No.4

본 연구는 H₂S를 TiO₂/SiO₂촉매상에서 산소와의 직접 산화 반응을 통해 원소 황의 형태로 제거하는 반응에 관한 것이다. 순수한 TiS₂Ti(SO₄)_2를 사용한 반응 실험과 순수한 TiO₂에 대한 주기적 온도 조작 실험 결과로부터 TiO₂는 황 회수 공정에서 사용되는 촉매의 비활성화의 주원인으로 알려진 sulfation이나 salfidation에 대해 매우 안정한 것으로 나타났다. TiO₂/SiO₂촉매에서 TiO₂의 담지량이 증가함에 따라 H₂S 전화율이 증가하였고, 원소 황의 선택도는 아주 소폭으로 감소하였다. 반응 실험결과 O₂/H₂S의 비가 증가할수록 원소 황의 선택도는 크게 감소하였다. 10 wt.% TiO₂/SiO₂ 촉매는 화학 양론비의 조성(H₂S=5 vol.% O₂=2.5 vol.%)의 반응물에 10 vol.%의 수증기를 첨가한 경우 활성과 선택도가 감소하였으나 여전히 80% 이상의 원소 황 수율을 유지하고 있었다. Selective catalytic oxidation of H₂S to elemental sulfur using TiO₂/SiO₂ catalysts was investigated in this study. The reaction test with pure TiS₂and Ti(SO₄)₂and cyclic temperature operation revealed that TiO₂had a good resistance to sulfation and sulfidation, which are known as the main cause of catalytic deactivation in sulfur recovery process. With the increase of TiO₂loading amount in Tio₂/SiO₂catalysts, the conversion of H₂S increased and the selectivity of elemental sulfur was very slightly decreased. As the ratio of O₂/H₂S increased, the selectivity to elemental sulfur was drastically decreased. In the presence of 10 vol.% water vapor to a stoichiometric mixture of H₂S and O₂(H₂S =5 vol.% O=2.5 vol.%), both activity and selectivity of 10 wt.% TiO₂/SiO₂catalyst are decreased, but it still showed more than 80% of sulfur yield.