• Journal of Gastric Cancer
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• 제8권4호
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• pp.169-175
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• 2008

목적: 대장암에서 microsatellite instability high (MSI-H)를 보인 환자가 microsatellite stable (MSS) 또는 microsatellite instability low (MSI-L)를 가진 그룹보다 예후가 좋은 것으로 되어 있으나 II기, III기 대장암에서 MSI-H를 보인 환자가 MSS 또는 MSI-L를 가진 그룹보다 5-fluorouracil (5-FU)에 대한 효과가 떨어진다는 연구 보고가 있다. Thymidylate synthase (TS)는 DNA 합성에 필요한 물질임과 동시에 5-FU의 표적물질이며 암환자에서 TS 발현율이 높을수록 5-FU에 의한 항암치료 효과가 감소한다. 이와 같이 MSI가 높을수록, TS 발현이 높을수록 5-FU에 대한 감수성이 떨어지기 때문에 MSI와 TS간의 상관관계를 밝히려는 연구가 대장암 환자를 대상으로 시도되었으나 현재까지의 결과는 상관관계가 있다는 보고와 없다는 보고가 있어서 일정하지 않다. 위암 환자에서는 MSI와 TS의 관계에 대한 연구는 없다. 따라서 본 연구에서는 위암 환자에서의 MSI와 TS 발현정도의 상관관계를 분석하였다. 대상 및 방법: 2004년 1월부터 2006년 5월까지 분당차병원에서 위암으로 근치적 위절제술을 시행 받은 환자 중 99명을 대상으로 MSI 및 TS 발현 정도를 비교 분석하였다. MSI는 5개의 표지자(BAT25, BAT26, D2S123, D5S346, D17S250)에 대해서 분석하였고 TS는 면역조직화학 염색으로 그 발현 정도를 측정하였다. 결과: 전체 99예의 환자에서 MSS/MSI-L 및 MSI-H인 경우가 각각 92 (92,9%), 7 (7.1%)예였고 TS에 대한 면역조직화학 염색 정도에 따라 negative, low TS 및 high TS인 경우는 각각 46 (46.5%), 33 (33.3%), 20 (20.2%)예였다. MSS/MSI-L 92예에서 TS의 negative, low TS, high TS는 각각 46 (50%), 30 (32.6%), 16 (17.4%)예였고 MSI-H인 7예에서는 TS의 negative, low TS, high TS가 0 (0%), 3 (42.9%), 4 (57.1%)예로 MSI-H 7예 모두에서 TS를 발현하였고 검정 결과 통계적으로 유의하게 MSI-H와 high TS 간에는 상관관계가 있었다. 결론: 위암환자에서 MSI-H를 보인 경우가 MSS/MSI-L를 보인 경우보다 더 높은 TS의 발현을 보였다.

• 현장농수산연구지
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• 제4권1호
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• pp.128-137
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• 2002

개발된 알루히트를 이용하여 지하수 이용 열교환기를 개발하였다. 시작기는 600mm, 700mm 알루히트 19개의 끝을 U자 용접을 하여 지하수가 직렬흐름이 되도록 2가지로 제작하였다. 성능시험은 개방된 공간에서 지하수 유량과 공기양의 변화를 주면서 상온에서 실시하였다. 1. 시작기의 열전달 계수는 33~156(W/m²℃) 범위로 나타나 설계가정 값에 잘 일치하는 것으로 판단되었다. 2. 열전달 면적이 증가할수록, 지하수 입·출구의 온도 차이가 클수록, 공기의 입·출구 온도 차이가 클수록, 또 송풍량이 증가할수록 에너지 전달량이 증가하였다. 3. 지하수 입·출구 온도 차이가 6℃ 이고 송풍량이 6,000m³/h일 때 전달 열용량은 6,825W였으며, 공기의 입·출구 온도 차이는 25.8℃에서 23.2℃로 -2.6℃의 강화 효과가 있었고, 대류열전달계수는 88.5W/m²℃ 였다. 4. 지하수 입·출구 온도 차이가 2℃ 이고 송풍량이 4,000m³/h일 때 전달 열용량은 2,625W으로 작았지만, 공기의 입·출구 온도 차이는 27℃에서 22.5℃로 -4.5℃의 강화 효과가 있었고, 대류열전달계수는 33.6W/m²℃였다. 5. 시작기 I, II, III의 전달 열용량 데이터 각각의 상관계수 R²은 0.9141, 0.8935, 0.9393이었으며, 공기유량이 6,000m³/h, 5,000m³/h, 4,000m³/h일 때 각각의 데이터 상관계수 R²은 0.9513, 0.9414, 0.9003으로 신뢰할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1551-1555
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• 2012

Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of benzyl 2-pyridyl carbonate $\mathbf{7}$ and $t$-butyl 2-pyridyl carbonate $\mathbf{8}$ with a series of alicyclic secondary amines in $H_2O$ at $25.0^{\circ}C$. Substrate $\mathbf{8}$ is less reactive than $\mathbf{7}$. Steric hindrance exerted by the bulky $t$-Bu group of $\mathbf{8}$ has been suggested to be responsible for the decreased reactivity. The Br${\o}$nsted-type plots for the reactions of $\mathbf{7}$ and $\mathbf{8}$ are linear with ${\beta}_{nuc}=0.49$ and 0.44, respectively, which is typical for reactions reported previously to proceed through a concerted mechanism. Aminolyses of $\mathbf{7}$ and $\mathbf{8}$ were expected to proceed through a zwitterionic tetrahedral intermediate $T^{\pm}$, which would be stabilized through an intramolecular H-bonding interaction. However, the kinetic results suggest that the reactions proceed through a concerted mechanism. The H-bonding interaction in $T^{\pm}$ has been suggested to accelerate the rate of leaving-group expulsion from $T^{\pm}$. Another factor that might accelerate expulsion of the leaving group is the "push" provided by the RO group in $T^{\pm}$ through resonance interactions. Thus, it has been concluded that the enhanced nucleofugality through the H-bonding interaction and the "push" provided by the RO group forces the reactions to proceed through a concerted mechanism.

• 한국결정학회지
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• 제4권1호
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• pp.25-35
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• 1993

Tetra-tert-butyl-tetrapropionyloxycalix (4) arena (C,6H,20s)의 분자 및 결정구조를 X-선 회절법으로 연구하였다. 이 결정은 삼사정계이고 공간군은 P1이다. 단위세포 길이는 a=13.664(5), b=17.585(5), c= 12.863(2)A이며 a=109.33(2), B=111.97(2), r=76.45(3) ˚, Z=2이다. 회절반점들의 세기는 흑연단색화 장치가 있는 Enraf-Nonius CAD-4 Diffractometer로 얻었으며, Mo-Ka X-선(A=0.7107A )을 사용하였다. 분자구조는 직접법으로 풀었으며 최소자 승법으로 정밀화하였다. 최종 신뢰도 R값은 2561개의 회절반점에 대하여 0.084이었다. 본 Calixarene은 partial cone conformation을 가져서 세개의 tort-butylphenyl group들과 하나의 tort-butylphenyl group의 상대적인 배열이 다르다. 세개의 propionyloxy group들은 macrocycle로 된 cavity바깥 쪽을 향하여 배열되어 있다.

• 한국응용곤충학회지
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• 제20권1호
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• pp.25-30
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• 1981

성 pheromone을 이용한 이화명나방의 교미교란효과를 구명하고저 합성 성 pheromone, (Z)-11-hexadecenal과 (Z)-13-octadecenal을 4,5 : 1로 공시하여 본 시험을 야외에서 수행한 결과 1화기에는 30a당 합성성 pheromone 29.3g 처리한 구에서 $90.4\%$의 교미교란효과가 인정되었고 2화기에는 $20m^2$당 합성 성 pheromone 33mg 처리까지도 교란효과가 있었다.

• 한국물환경학회지
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• 제33권4호
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• pp.441-448
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• 2017

Microcystis aeruginosa (M. aeruginosa) is a cyanobacterium species that can form harmful algal blooms in freshwater bodies worldwide. The use of Artemisia asiatica extracts to control M. aeruginosa inhibition will be environmentally friendly and promising. Artemisia asiatica extracts removed successfully upto 88% of M. aeruginosa pH 8 at $25^{\circ}C$ of temperature. These results was indicated that the amount of 2.24 g/L Artemisia asiatica extracts was removed 1g dryweight/L of M. aeruginosa. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the M. aeruginosa was grown in medium containing 2.5 g/L of initial concentration of Artemisia asiatica extracts. In the various growth control models, Luong model showed the highest correlation coefficient of 0.9916. Therefore, the Luong model was the most suitable control model for the growth control of M. aruginosa using Artemisia asiatica extracts. In conclusion, the growth control of M. aruginosa using Artemisia asiatica extracts can be applied in the field without controlling the temperature and pH of rivers and streams, and it is possible to control the growth of M. aruginosa efficiently in a short time. The natural extract, Artemisia asiatica extracts, can be a promising inhibition due to its high efficiency and low dose requirements.

• Mycobiology
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• 제33권4호
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• pp.230-234
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• 2005

Oudemansiella radicata, one of edible mushrooms belonging to Tricholomataceae of Basidiomycota, has been known to exhibit outstanding therapeutic effects on the hypertension caused by high blood pressure and inhibitory effects on the sarcoma 180 and Erhrlich carcinoma of mice. As one of preliminary experiments for producing fruiting-body of O. radicata, this study was carried out to obtain the basic information for culture conditions of mycelial growth of the fungus. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and pH 6, respectively. The medium for favorable mycelial growth of O. radicata was shown in the Lilly medium, whereas compact mycelial density was found in Hamada medium. The carbon and nitrogen sources promoting for mycelial growth of O. radicata were xylose and alanine, respectively. The optimum C/N ratio was about 20 : 1 in case that 3% glucose was supplimented to the basal medium as a carbon source.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.270-274
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• 2012

The nucleophilic substitution reactions of 1,2-phenylene phosphorochloridate (1c) with X-pyridines are investigated kinetically in acetonitrile at $-25.0^{\circ}C$. The free energy correlations for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Ph. The pyridinolysis rate of 1c with a cyclic five-membered ring is $2.70{\times}10^5$ times faster than its acyclic counterpart (1a: phenyl ethyl chlorophosphate) because of great positive value of the entropy of activation of 1c (${\Delta}S^{\neq}$ = +26 eu) compared to negative value of 1a (${\Delta}S^{\neq}$= -24 eu) over considerably unfavorable enthalpy of activation of 1c (${\Delta}H^{\neq}=20.5kcal\;mol^{-1}$) compared to 1a (${\Delta}H^{\neq}=12.7kcal\;mol^{-1}$). Great enthalpy and positive entropy of activation are ascribed to sterically congested transition state (TS) and solvent structure breaking in the TS. A concerted mechanism involving a change of nucleophilic attacking direction from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines is proposed on the basis of greater selectivity parameters (${\rho}_X$ = -1.99 and ${\beta}_X$ = 0.41) with the strongly basic pyridines compared to those (${\rho}_X$ = -0.42 and ${\beta}_X$ = 0.07) with the weakly basic pyridines.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2229-2237
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• 2012

The two chelates based on calix[4]arene and thiacalix[4]arene have been synthesized and used as neutral ionophores for preparing PVC based membrane sensor selective to $Ho^{3+}$ ion. The addition of potassium tetrakis(4-chlorophenyl)borate (KTpClPB) and various plasticizers, viz., NDPE, o-NPOE, DOP, TEP and DOS have been found to improve significantly the performance of the sensors. The best performance was obtained with the sensor no. 6 having membrane of $L_2$ with composition (w/w) ionophore (2%): KTpClPB (4%): PVC (37%): NDPE (57%). This sensor exhibits Nernatian response with slope $21.10{\pm}0.3mV/decade$ of activity in the concentration range $3.0{\times}10^{-8}-1.0{\times}10^{-2}M\;Ho^{3+}\;ion$, with a detection limit of $1.0{\times}10^{-8}M$. The proposed sensor performs satisfactorily over a wide pH range of 2.8-10, with a fast response time (5 s). The sensor was also found to work successfully in partially non-aqueous media up to 25% (v/v) content of methanol, ethanol and acetonitrile, and can be used for a period of 4 months without any significant drift in potential. The electrode was also used for the determination of $Ho^{3+}$ ions in synthetic mixtures of different ions and the determination of the arsenate ion in different water samples.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4074-4078
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• 2012

The first step in the common pathway for the biosynthesis of branched chain amino acids is catalyzed by acetohydroxyacid synthase (AHAS). The AHAS is found in plants, fungi and bacteria. With an aim to identify new anti-tuberculosis drugs that inhibit branched chain amino acid biosynthesis, we screened a chemical library against Mycobacterium tuberculosis AHAS. The screening identified four compounds, AVS 2087, AVS 2093, AVS 2236, and AVS 2387 with $IC_{50}$ values of 0.28, 0.21, 3.88, and $0.25{\mu}M$, respectively. Moreover, these four compounds also showed strong inhibition against reconstituted AHAS with $IC_{50}$ values of 0.37, 0.26, 1.0, and $1.18{\mu}M$, respectively. The basic scaffold of the AVS group consists of 1-pyrimidin-2-yl-1H-[1,2,4]-triazole-3-sulfonamide. The most active compound, AVS 2387, showed the lowest total interaction energy -8.75 Kcal/mol and illustrates its binding mode by hydrogen bonding with $H_{\varepsilon}$ of Gln517 with the distance of $2.24{\AA}$.