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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.
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.
Although H-1 parvovirus is used as an antitumor agent, not much is known about the relationship between its specific tropism and oncolytic activity. We hypothesize that VP2, a major capsid protein of H-1 virus, determines H-1-specific tropism. To assess this, we constructed chimeric H-1 viruses expressing Kilham rat virus (KRV) capsid proteins, in their complete or partial forms. Chimeric H-1 viruses (CH1, CH2 and CH3) containing the whole KRV VP2 domain could not induce cytolysis in HeLa, A549 and Panc-1 cells. However, the other chimeric H-1 viruses (CH4 and CH5) expressing a partial KRV VP2 domain induced cytolysis. Additionally, the significant cytopathic effect caused by CH4 and CH5 infection in HeLa cells resulted from preferential viral amplification via DNA replication, RNA transcription and protein synthesis. Modeling of VP2 capsid protein showed that two variable regions (VRs) (VR0 and VR2) of H-1 VP2 protein protrude outward, because of the insertion of extra amino-acid residues, as compared with those of KRV VP2 protein. This might explain the precedence of H-1 VP2 protein over KRV in determining oncolytic activity in human cancer cells. Taking these results together, we propose that the VP2 protein of oncolytic H-1 parvovirus determines its specific tropism in human cancer cells.
<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>
<P>Yeast peroxiredoxin II (yPrxII) is an antioxidant enzyme that plays a protective role against the damage caused by reactive oxygen species (ROS) in Saccharomyces cerevisiae. This enzyme consists of 196 amino acids containing 2-Cys Prx with highly conserved two active cysteine residues at positions 48 and 171. The yPrxII has dual enzymatic functions as a peroxidase and molecular chaperone. To understand the effect of additional cysteine residues on dual functions of yPrxII, S79C-yPrxII and S109C-yPrxII, the substitution of Ser with Cys residue at 79 and 109 positions, respectively, was generated. S109C-yPrxII and S79C-yPrxII showed 3.7- and 2.7-fold higher chaperone and peroxidase activity, respectively, than the wild type (WT). The improvement in enzyme activity was found to be closely associated with structural changes in proteins. S109C-yPrxII had increased beta-sheet in its secondary structure and formed high-molecular-weight (HMW) as well as low-molecular-weight (LMW) complexes, but S79C-yPrxII formed only LMW complexes. HMW complexes predominantly exhibited a chaperone function, and LMW complexes showed a peroxidase function. In addition, transgenic yeast cells over-expressing Cys-substituted yPrxII showed greater tolerance against heat and oxidative stress compared to WT-yPrxII.</P>
성장단계별 농후사료 급여수준이 한우 육성빈우의 체중변화 및 번식능력에 미치는 효과를 구명하기 위하여 6개월령에 이유된 한우암송아지40두(평균체중 126.8㎏)에 대해 성장단계(육성기, 6∼12개월령; 성성숙기, 12∼18개월령; 임신기, 18∼24개월령) 및 사료 급여형태(H, 농사료 체중의 1% 및 조사료 자유채식; L. 농후사료 무급여 및 조사료 자유채식)에 따라 4처리(T₁, L-L-H; T₂, L-H-H; T₃, H-L-H; T₄, H-H-H)를 두고 540일간 사양시험을 한 결과를 요약하면 다음과 같다. 1. 월령별 체중은 처리구에 따라 6, 12, 18 및 24개월령 체중이 각각 124.2∼129.8(평균 126.8), 168.6∼209.0(평균 187.6), 213.8∼276.4(평균 250.5) 및 278.0∼351.2㎏(평균 323.4㎏)이었으며, 농후사료 급여수준이 증가할수록 유의적으로(P$lt;0.05) 증가하는 것으로 나타났다. 2. 공시기간 동안의 처리별 평균 일당증체량은 T₄, T₂, T₃및 T₁순으로 높았으며 각각 0.42, 0.40, 0.36 및 0.29㎏이었고, 조사료만 급여시는 0.23㎏이었다. 3. 전기간 ㎏증체를 위해 소요된 TDN량은 T₄, T₂, T₃및 T₁순으로 적어 각각 10.53, 10.61, 11.45 및 12.67㎏ 이었고 농후사료 급여수준이 증가할수록 사료효율이 개선되는 것으로 나타났으며 이때의 조농비율중 조사료 비율은 각각 69.9, 70.4, 80.3 및 87.9%였다. 4. 초발정 월령 및 체중은 각각 14.6∼17.1개월령(평균 15.7개월령), 209.5∼237.5㎏(평균 230.0㎏), 초임월령 및 체중은 각각 17.6-22.1개월령(평균 19.5개월령) 및 260.1∼272.3㎏(평균 266.2㎏) 그리고 초산월령 및 체중은 각각 26.9∼31.0개월령(평균 28.7개월령) 및 344.1∼382.9㎏(평균 372.5㎏)이었으며 농후사료 급여수준이 증가할수록 초 발정 초임 및 초산시의 월령은 짧아지고 체중은 증가하였지만 임신기간 및 송아지 생시체중은 뚜렷한 차이가 없었다. 5. 체위 증가율은 전처리 모두 흉폭, 요각폭 및 곤폭 순으로 높았으며, 농후사료 급여수준이 증가할수록 체중/체장 및 체중/체고의 비증가하였다. 6. 소득은 T₄, T₂, T₃및 T₁순으로 높았으며, 농후사료 급여수준이 가장 높았던 T₄가 가장 낮았던 T₁보다 15% 증가한 것으로 나타났다. 이상과 같은 결과들을 종합해 볼 때 6개월령 이후 초산시 까지의 한우 번식우는 4계절 동안 Timothy 위주 혼합 목건초의 자유채식만으로도 무축사 야외사육이 가능하지만 적정성장 및 번식능력 개선을 위해 육성기부터 초산시까지 전기간 동안 농후사료를 체중의 1% 수준으로 급여하는 것이 바람직할 것으로 판단된다. This study was conducted to investigate the effect of concentrate feeding levels(H : 1.0% of apparent body weight in concentrate and full feeding of roughage, L : full feeding of roughage only) by growth-stage(6 to 12, 12 to 18 and 18 to 24 month of age) on the body weight gain and reproductive performance. Feeding trial was conducted with 4 treatment groups(T₁, L-L-H; T₂, L-H-H; T₃, H-L-H and T₄, H-H-H) for 540 days. consisting of 40 spring born Korean native female calves which initially weight was about 126.8 ㎏. The results obtained are summarized as follows; 1. The average body weight at 6, l2, l8 and 24 months of age by treatments were 124.2 to 129.8(average 126.8), 168.6 to 209.0(average 187.6), 213.8 to 276.4(average 250.5) and 278.0 to 351.2㎏(average 323.4㎏), respectively, and their body weights increased with the level of concentrate feeding. 2. During the total experimental period, average daily gains by treatments ranged from 0.29 to 0.42㎏(average 0.37㎏) and higher in the order of T₄, T₂, T₃and T₁. 3. TDN intakes required per unit of kilogram gain and the rate of roughage to concentrate by treatments were 10.53 to 12.67㎏(average 11.31㎏) and 69.6 to 87.9%(average 77.1%), respectively, and the former were lower in the order of T₄, T₂, T₃and T₁, but the latter were highs in the order of T₄, T₃, T₂and T₁, respectively. The feed efficiency increased with the level of concentrate feeding. 4. The ages at puberty, first conception and paturition by treatments were 14.6 to 17.1(average 15.7), 17.6 to 22.1(average 19.5) and 26.9 to 31.0 months(average 28.7 months), respectively, and the body weight were 209.5 to 237.5(average 230.0), 260.1 to 272.3(average 266.2) and 344.1 to 382.9㎏(average 372.5㎏), respectively, and the ages at puberty, first conception and parturition were shorter and the body weight were heavier by increasing the level of concentrate feeding. 5. In all treatment groups, increase rate of body measurements were higher in the order of chest width, hip width and pelvis width, and the rate of body length and wither height to body weight increased with the level of concentrate feeding. 6. Income were higher in the order of T₄, T₂, T₃and T₁, and income of T₄was increased by 15%, compared with that of T₁. It was concluded that Korean native heifers could be raised under full feeding of mixed grass hay through all 4 seasons outdoors, but it was desirable that high energy concentrate would be added at about 1.0% of apparent body weight for the improved reproductive performance.
성장단계별 농후사료 급여수준이 육량 및 육질에 미치는 효과를 구명하기 위하여 6개월령에 이유된 비거세 한우 수 송아지 30두(평균체중 125㎏)를 성장단계(육성기 : 6∼12개월령, 비육전기 : 12∼18개월령, 비육후기 : 18∼24개월령) 및 사료 급여형태(H : 농후사료 및 조사료 자유채식, M : 농후사료 체중의 1% 및 조사료 자유채식, L 농후사료 무급여 및 조사료 자유채식)에 따라 6처리 (T₁: H-H-H, T₂: H-M-H, T₃: M-H-H, T₄: M-M-H, T_5 : L-H-H, T_6 : L-L-H)를 두고 540일간 사양시험한 결과를 요약하면 다음과 같다. 1. 비육 전기간의 일당증체량은 T₁, T₃, T₂, T₄, T_5 및 T_6 순으로 높았으며 각각 0.955, 0.941, 0.898, 0.889, 0.865 및 0.709㎏ 이었다. 2. 비육 전기간 ㎏증체를 위해 소요된 TDN량은 T₃, T_5, T₄, T_6, T₁및 T₂순으로 적었고 각각 6.38, 6.44, 6.50, 6.62, 6.69 및 6.86㎏이었으며, 이 때의 조농비율중 조사료비율은 각각 33.0, 36.2. 47.8, 60.5. 23.2% 및 33.1%였다. 3. 처리구별 도체중, 도체율, 등지방두께 및 배최장근 단면적은 각각 277.2∼377.4㎏(평균 338.6㎏), 56.1∼59.2% (평균 57.7%), 0.5∼0.96㎝(평균 0.82㎝), 및 75.4∼95.4㎠(평균 87.6㎠)였으며 육성기간 중에 농후사료 급여량이 많았던 처리에서 우수한 것으로 나타났다. 4. 육질은 T₁에 비해 T₂와 T_5에서 높았으며, 처리별 1등급 출현두수는 T₂에서 4두, T_5에서 3두 그리고 나머지 처리에서 1두 또는 전혀 없었다. 5. 고급육을 생산하는 개체들은 요각 및 곤폭등 후구의 증가율이 높았고 특히 체중/체고 값의 증가율이 높은 것으로 나타났다. 6. 소득은 T₃, T₁, T₂, T_5, T₄및 T_6 순으로 높았지만 T₁, T₂및 T₃사이에는 뚜렷한 차이가 없었다. 이상과 같은 결과들을 종합해 볼 때 한우 비거세 수 송아지를 고급육 생산을 위해 24개월령까지 농후사료 위주로 장기비육 할 때는 비육전기 또는 육성기만은 농후사료 급여수준으로 체중의 1%수준 이하로 줄이는 것이 바람직한 것으로 판단된다. This study was conducted to investigate, the effects of concentrate feeding levels(H : full feeding of concentrate and roughage, M : 1.0% of apparent body weight in concentrate and full feeding of roughage, L: full feeding of roughage only) by growing-fattening steps(6 to 12, 12 to 18 and l8 to 24 month of age) on the feed efficiency, meat quantity and quality. Feeding trial was conducted with 6 treatment groups which were T₁(H-H-H), T₂(H-M-H), T₃(M-H-H), T₄(M-M-H), T_5(L-H-H) and T_6(L-L-H) for 540 days, consisting of 30 Korean native male calves whose initially weights were about 125.0㎏. The results obtained are summarized as follows; I. During the over-all period, average daily gains by treatments were 0.709 to 0.955㎏(average 0.876㎏) and increased higher in the order of T₁, T₃, T₂, T₄, T_5 and T_6. 2. TDN intakes required per unit of kilogram-gain and the rate of roughage to concentrate by treatments were 6.38 to 6.86㎏(average 6.58㎏) and 23.2 to 60.5%(average 39.0%), respectively and the former were decreased in the order of T₃, T_5, T₄, T_6, T₁and T₂but the latter were increased in the order of T_6, T₄, T_5, T₂, T₃and T₁. 3. Carcass weight, dressing percent back-fat thickness and loin eye muscle area by treatments were 277.2 to 377.4㎏ (average 338.7㎏), 56.1 to 59.2%(average 57.7%), 0.50 to 0.96㎝(average 0.82㎝) and 75.4 to 95.4㎠(average 87.6㎠), respectively, and were improved in treatment groups which were high of concentrate feeding levels during the growing period. 4. Meat quality was higher in T₂and T_5 groups than in T₁(control), and heads of first grade were 4 in T₂, 3 in T_5 and 1 or none at the rest treatments. 5. In T₂and T_5 groups with a lot of heads at first grade of meat quality, the increase rate of hip- and pelvis-width was higher than those in the rest treatments, and especially higher in the increase rate of body-weight to wither-height. 6. Although income by treatment groups were increased in the order of T₃, T₁, T₂, T_5, T₄and T_6, there was not differences between T₂or T₃and T₁. It is concluded that the growing-fattening Korean native bulls are raising by concentrate full feeding method from 6 to 24 month of age may be required to feed no more than 1% of concentrate based on the body weight during the fattening (12 to 18 month of age) or growing(6 to 12 month of age) period to produce high quality meat.
Plant homeodomain finger 2 (PHF2) has a role in epigenetic regulation of gene expression by demethylating H3K9-Me2. Several genome-wide studies have demonstrated that the chromosomal region including the PHF2 gene is often deleted in some cancers including colorectal cancer, and this finding encouraged us to investigate the tumor suppressive role of PHF2. As p53 is a critical tumor suppressor in colon cancer, we tested the possibility that PHF2 is an epigenetic regulator of p53. PHF2 was associated with p53, and thereby, promoted p53-driven gene expression in cancer cells under genotoxic stress. PHF2 converted the chromatin that is favorable for transcription by demethylating the repressive H3K9-Me2 mark. In an HCT116 xenograft model, PHF2 was found to be required for the anticancer effects of oxaliplatin and doxorubicin. In PHF2-deficient xenografts, p53 expression was profoundly induced by both drugs, but its downstream product p21 was not, suggesting that p53 cannot be activated in the absence of PHF2. To find clinical evidence about the role of PHF2, we analyzed the expressions of PHF2, p53 and p21 in human colon cancer tissues and adjacent normal tissues from patients. PHF2 was downregulated in cancer tissues and PHF2 correlated with p21 in cancers expressing functional p53. Colon and stomach cancer tissue arrays showed a positive correlation between PHF2 and p21 expressions. Informatics analyses using the Oncomine database also supported our notion that PHF2 is downregulated in colon and stomach cancers. On the basis of these findings, we propose that PHF2 acts as a tumor suppressor in association with p53 in cancer development and ensures p53-mediated cell death in response to chemotherapy.
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.