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검색결과 20,882건 처리시간 0.046초

Selective Synthesis of a New Macropolycycle Containing One N-CH2-N Linkage and Its Reaction with Cu2+ and Ni2+ Ions in Methanol

  • Kang, Shin-Geol;Kweon, Jae-Keun;Jeong, Gyeong-Rok;Lee, Uk
    • Bulletin of the Korean Chemical Society
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    • 제29권10호
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    • pp.1905-1910
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    • 2008
  • The reaction of 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.0$0^{1.18}.0^{7.12}$]docosane ($L^1$) with formaldehyde in warm methanol yielded 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.$1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^7$) containing one 1,3-diazacyclohexane subunit. In methanol, $L^7$ readily reacts with $Cu^{2+}$ ion to form [$CuL^7(H_2O)$]$^{2+}$ which is extremely inert against methanolysis. In the solution containing $Ni^{2+}$ ion, however, $L^7$ reacts with methanol to yield [$NiL^3$]$^{2+}$ ($L^3$ = 2-(methoxymethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.$0^{1.18}.0^{7.12}$]- docosane), in which one N-$CH_2OCH_3$ pendant arm is appended. The copper(II) complex [$CuL^7(H_2O)$]- $(ClO_4)_2{\cdot}3H_2O\;(I{\cdot}3H_2O)$ has a severely distorted trigonal bipyramidal coordination geometry with a 4-5- 6-5 chelate ring sequence. The crystal structure of [$NiL^3$]$(PF_6)_2{\cdot}2H_2O$ (IIb) shows that the N-$CH_2OCH_3$ pendant arm is not coordinated to the metal ion in the solid state. In various solvents (S), however, the nickel(II) complex exists as a mixture of [$NiL^3$(S)]$^{2+}$, in which the N-$CH_2OCH_3$ group as well as S is coordinated to the metal ion, and [$NiL^3$]^{2+}.

Antimicrobial Activity of Glycerol Monolaurate and Organic Acids on the Survival of Escherichia coli O157:H7

  • Lee, Myung-Ki;Park, Boo-Kil;Jeong, Cha-Kweon;Oh, Deog-Hwan
    • Preventive Nutrition and Food Science
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    • 제6권1호
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    • pp.6-9
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    • 2001
  • Minimal inhibitory concentrations (MIC) and antimicrobial effects of glycerol monolaurate (monolaurin) and organic acids, either alone or in combination, against Escherichia coli O157:H7 in tryptic soy broth were determined. MIC values of monolaurin(ML), acetic (AA), citric (CA), lactic (LA) and hydrochloric acid (HCl) were 300$\mu\textrm{g}$/mL (0.03%), 1250$\mu\textrm{g}$/mL(0.125%), 5000$\mu\textrm{g}$/mL(0.5%), 2500$\mu\textrm{g}$/mL(0.25%) and 2500$\mu\textrm{g}$/mL(0.25), respectively. When 150$\mu\textrm{g}$/mL of ML was combined with 50$\mu\textrm{g}$/mL AA, 250$\mu\textrm{g}$/mL HCl and 125$\mu\textrm{g}$/mL LA, the combined agents did not increase the inhibitory effect of the most active single compound alone. This result indicates that there was little interaction between ML and A, HCl and LA. However, the combination of 150$\mu\textrm{g}$/mL ML and 250$\mu\textrm{g}$/mL CA synergistically inhibited growth of E. coli O157:H7. The present study showed that the nature of combined antimicrobial response against E. coli O157:H7 was complex, but this information would be useful for determining interaction that could compromise effectiveness in food systems.

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Agrocybe Cylindracea의 영양배지 조성 및 배양조건의 최적화 (Optimization of Media Composition and Cultivation for the Mycelial Growth of Agrocybe Cylindracea)

  • 이재성;박신;박경숙
    • 한국식품과학회지
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    • 제21권3호
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    • pp.399-403
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    • 1989
  • A. cylindracea의 균사 성장을 위한 영양배지 조성 및 배양조건을 최적화하였다. 최적 영양배지 조성은 starch 20.0g/l, bacto-soytone 4.0g/l, 그리고 yeast extract 6.0g/l였다. 무기염류 $KH_2PO_4\;0.46g/l,\;K_2HPO_4\;1.0g/l,\;MgSO_47H_2O\;0.5g/l$을 첨가한 배지의 pH는 5.8로_ 완충되었으며 무기염류를 첨가하지 않은 배지보다 균사성장이 양호하였다. 균사의 최적 배양온도는 $28^{\circ}C$였으며 최적 생장 pH는 6.0이었다. 균사 성장 온도범위는 $10-35^{\circ}C$로서 $40^{\circ}C$ 이상에서는 균사가 사멸하였다.

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Antigenotoxic Effects of Satureja hortensis L. on Rat Lymphocytes Exposed to Oxidative Stress

  • Mosaffa Fatemeh;Behravan Javad;Karimi Gholamreza;Iranshahi Mehrdad
    • Archives of Pharmacal Research
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    • 제29권2호
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    • pp.159-164
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    • 2006
  • The protective properties of Satureja hortensis L. on the rat lymphocytes DNA lesions were tested. Lymphocytes were isolated from blood samples taken from healthy rats. DNA breaks and resistance to $H_{2}O_{2}$-induced damage were measured with the comet assay. Rat lymphocytes were incubated in S. hortensis ethanolic extract (SHE) (0.05, 0.1, 0.5, 1.0, and 2.5 mg/mL), essential oil (SHEO)(0.05, 0.1, 0.5, 1.0, and 2.5 ${mu}L/mL$), $H_{2}O_{2}$ (50, 100, and 200 ${\mu}M$), a combination of $H_{2}O_{2}$ (200 mM) with either SHE (1.0, 2.5 mg/mL) or SHEO (1.0, 2.5 ${\mu}L/mL$) at $4^{\circ}C$ for 30 min, and the extent of DNA migration was measured using a single-cell microgel electrophoresis technique under alkaline conditions. Treatment of rat lymphocytes with SHE or SHEO resulted in significant reduction of $H_{2}O_{2}$-induced DNA damage compared to controls. SHE exhibited a significant (P<0.01) inhibitory effect on oxidative DNA damage at 2.5 mg/mL. SHEO (1.0 and 2.5 ${\mu}L/mL$) also showed significant inhibitory effects (P<0.01) on $H_{2}O_{2}$ induced chromosomal damage. In conclusion both the ethanolic extract and the essential oil of the plant reversed the oxidative damage to rat lymphocytes induced by hydrogen peroxide.

The Co-luminescence Groups of Sm-La-pyridyl Carboxylic Acids and the Binding Characteristics between the Selected Doped Complex and Bovine Serum Albumin

  • Yang, Zhengfa;Tang, Ruiren;Tang, Chunhua
    • Bulletin of the Korean Chemical Society
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    • 제33권4호
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    • pp.1303-1309
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    • 2012
  • A novel ligand N,N'-(2,6-pyridinedicarbonyl)bis[N-(carboxymethyl)] (L1) was designed and synthesized. Four co-luminescence groups of Sm-La-pyridyl carboxylic acids systems were researched, which are $K_4Sm_{(1-x)}-La_x(L_1)Cl_3{\cdot}y_1H_2O$, $K_4Sm_{(1-x)}La_x(L_2)Cl_3{\cdot}y_2H_2O$, $K_6Sm_{2(1-x)}La_{2x}(L_3)Cl_6{\cdot}y_3H_2O$, $K_4Sm_{(1-x)}La_x(L_4)Cl_3{\cdot}y_4H_2O$. The results indicated the addition of La(III) could sensitize the luminescence of Sm(III) obviously in a certain range, enhancing emission intensity of Sm-pyridyl carboxylic acids relative to the undoped ones. The optimal mole percentages of La(III) in the mixed ions for $L_1$, $L_2$, $L_3$, $L_4$ were confirmed to be 0.6, 0.5, 0.3, 0.6, respectively. The mechanism of the fluorescence enhancement effect was discussed in detail. Furthermore, the binding interaction of $K_4Sm_{0.4}La_{0.6}(L_4)Cl_3{\cdot}5H_2O$ with bovine serum albumin (BSA) have been investigated due to its potential biological activity. The binding site number n was equal to 1.0 and binding constant $K_a$ was about $2.5{\times}10^5\;L{\cdot}mol^{-1}$.

제설제 피해지에서 토양개량제 처리에 따른 구절초의 생육특성 비교 (Growth of Dendranthema zawadskii in Chloride-containing De-icing Salt Areas Upon Treatment With Soil Amendments)

  • 주진희;양지;박선영;윤용한
    • 한국환경과학회지
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    • 제30권3호
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    • pp.235-243
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    • 2021
  • This study was conducted to investigate the growth of Dendranthema zawadskii in damaged soils when they are treated with improvement agents. The treatments consisted of a control (unamended field soil) and the application of a loess ball of 1 cm to the field soil. According to the degree of damage the de-icing agent had caused, the soils were divided into 3 areas (based on the yellowing of Pinus densiflora for. multicaulis in soil surveys): H (high saline), M (medium saline), and L (low saline). A total of six treatments were performed: D. zawadskiia plant without soil amendment (H; high saline soil, M; medium saline soil, L; low saline soil), and a D. zawadskiia plant with loess ball on the soil surface (H.L; high saline soil with loess ball, M.L; medium saline soil with loess ball, L.L; low saline soil with loess ball). The results showed that D. zawadskiia growth went from highest to lowest in the order: M.L > L.L > M > L > H.L > H. Plant growth results showed that soils treated with soil amendments (loess ball) were better for D. zawadskii growth than untreated soils.

Chlorella vulgaris의 이산화탄소 고정 및 수소생성 특성

  • 김철경;박기용;박준성;김남기
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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    • pp.69-72
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    • 2000
  • Chlorella vulgaris를 이용하여 기본배지에서 초기 주입농도 $0.7{\times}10^4\;cells/mL$ 상태에서 300시간 배양 후 $1.21{\times}10^5\;cells/mL$의 생체수를 얻었으며, 초기 cell 농도가 0.30g/L인 경우가 성장률이 $0.162g/L\;{\cdot}\;day$로 우수하였다. Glucose 초기농도가 2.00g/L인 경우 초기 cell 농도 0.025g/L에서 140시간 후 0.874g/L이 되었으며 비성장속도는 $0.243h^{-1}$을 나타내었고, 72시간내에 가스를 268mL를 생성하였으며 이후로는 수소 생성이 종료으나 순수 소소를 19.87mol% 함유하고 있었다. Chlorella vulgaris의 조성을 원소분석기로 분석한 결과 $C_{1.000}\;H_{1.774}\;N_{0.125}\;O_{0.557}$가 되었으며 이산화탄소 전환율은 $0.616cells/\;g\;CO_2$가 됨을 알 수 있었다.

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토양산도가 무궁화의 생장 및 화색에 미치는 영향 (Effect of Soil pH on Growth and Flower Color in Hibiscus siriacus L.)

  • 박형순;정현관;김세현;정동준;한진규;조윤진
    • 한국자원식물학회지
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    • 제19권1호
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    • pp.144-149
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    • 2006
  • 본 연구는 나라꽃 무궁화의 아름다움을 나타내는 화색에 미치는 요인 중 토양산도와 무궁화의 화색특성과 생장과의 관계를 조사 연구함으로써 가장 이상적인 색깔을 갖추는 pH 범위를 파악하여 무궁화 화색육종 계획의 기초를 마련하고자 하였다. 토양산도별 생육특성을 조사하고 분석한 결과 홍화랑과 영광 품종은 pH 7에서 엽수가 183.73개와 135.87개로 가장 높게 나타났으며 pH가 증가함에 따라 증가하였다. 토양산도별 4품종의 화색변화를 조사하고 분석한 결과 홍화랑 품종은 pH가 높아짐에 따라 L값은 $17.05{\sim}12.26$로 점점 낮아졌으며 a값은 $16.37{\sim}20.91$로 점점 높게 나타났다.

Pseudomonas sp. KDi19를 이용한 액체배지내에서 경유의 생물학적 분해 (Biodegradation of Diesel with Pseudomonas sp, KDi19 in Liquid Medium)

  • 윤민우;정정화;장순웅;공성호;이종렬;강동효;이상섭
    • 대한환경공학회지
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    • 제27권12호
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    • pp.1285-1291
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    • 2005
  • 본 연구에서는 유류로 오염된 주유소 저장 창고 밑부분의 토양에서 경유 분해 균주를 순수분리한 후, 스크린 테스트를 거쳐 고효율의 경유분해균주 KDi19를 선별하였다. KDi19균주는 16S rDNA 분석, 지방산 분석, 생리 생화학적 특징 그리고 형태학적 특징을 확인한 결과 Pseudomonas sp.로 동정되었다. KDi19는 온도 $30^{\circ}C$, pH 7, 그리고 균농도 1.0 g/L의 조건에서 48시간 동안 초기 1,000 mg/L의 경유 중 956.3 mg/L(95.6%)를 제거하였다. 또한 균농도 1.0 g/L, pH 7의 조건에서, 낮은 온도($20^{\circ}C$, $15^{\circ}C$, $10^{\circ}C$) 적용 시, 경유 1,000 mg/L을 48시간 동안 각각 63.9%, 18.5%, 17.0% 제거하였다. 마지막으로 균 농도 1.0 g/L, pH 7, 온도 $30^{\circ}C$ 조건일 경우, KDi19는 저농도 경유 50 mg/L와 100 mg/L를 24시간 동안 각각 49.0 mg/L(97.9%)와 96.2 mg/L(96.2%)를 제거하였다.

슬러지 냉동처리에 의한 갈조류로부터 바이오가스 생산 (Freeze Treatment of Sludge for the Biogas Production from Brown Macroalgae)

  • 김지윤;정행순;우대식;김상민;김인수;이재화
    • 공업화학
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    • 제23권6호
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    • pp.594-598
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    • 2012
  • 본 연구에서는 해조류 다시마를 바이오매스로 이용하는 혐기성 소화로부터 바이오가스를 생산하였다. 최적의 혐기성 배양조건을 확립하기 위해 슬러지는 $-70^{\circ}C$에서 20 min 동안 냉동 전처리를 하였다. 대조군과 비교했을 때 수소와 메탄가스는 각각 2.7배와 3.4배 증가한 667.28 mL/L와 3420.24 mL/L를 생산하였다. 냉동 전처리한 슬러지의 초기 pH 최적 조건은 7.0이었고, 다시마 바이오매스의 초기 pH 최적 조건은 8.0이었으며 알칼리 조건에서 보다 산성 조건에서 바이오가스 생산량이 크게 감소하는 것을 확인할 수 있었다. 슬러지의 냉동 전처리와 바이오매스 및 슬러지의 최적 pH 조건에서 최대 643.73 mL/L의 수소와 4291.6 mL/L의 메탄가스를 생산하였다. 이는 대조군과 비교했을 때 각각 2.6배와 4.3배 증가한 생산량이었다. 또한 최적 조건의 5-L 회분식 혐기성 배양에서 바이오가스의 생산량을 측정한 결과 기질에 포함된 다시마에 의해 생산될 수 있는 최대 생산량은 수소 1605.03 mL/L와 메탄가스 4593.71 mL/L로 확인되었다.