• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.497-502
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• 1994

A new chiral stationary phase (CSP) for the liquid chromatographic resolution of enantiomers was prepared from (S)-naproxen and 3,5-dinitroaniline. The 6-alkoxy-2-naphthyl group of the CSP was presumed to act as a ${\pi}$-basic interaction site for resolving ${\pi}$-acidic racemates while the 3,5-dinitroanilide group of the CSP was presumed to play a role as a ${\pi}$-acidic interaction site for resolving ${\pi}$-basic racemates. From the chromatographic resolution trends of N-alkylamide derivatives of ${\alpha}$-arylalkylamines on the CSP prepared, the chiral recognition mode involving the intercalation of the amide alkyl chain of the less retained enantiomers between the connecting tethers of the CSP was proposed.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1177-1180
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• 2009

• Polymer(Korea)
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• v.33 no.3
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• pp.207-212
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• 2009

The precursor polyimide of the photoreactive polyimides(PI-SP6 and PI-SP12) was prepared from a derivative of 2, 2, 2-trifluoroethane dianhydride and 3,3'-dihydroxy-4,4'-diaminobiphenyl. PI-SP6 and PI-SP12 were then prepared by the polymer reactions of the precursor polyimide with photoreactive 2-styrylpyridine alkylene (hexylene and dodecylene) derivatives, respectively. The photoreactive polymers were soluble in organic solvents. The polymers showed the initial decomposition temperatures around $350^{\circ}C$. The glass transition temperatures of PI-SP6 and PI-SP12 were found to be $130^{\circ}C$ and $85^{\circ}C$, respectively. This result means that the latter polymer is more flexible than the former polymer. Their transmittance in the film state was 90% at $250^{\circ}C$, which indicates that the photosensitive polyimides with thermal stability have high optical transparency even at the high temperature. The respective dichroic ratios of PI-SP6 and PI-SP12 were found to be 0.01 and 0.03 at an exposure energy of $1.5\;J/cm^2$. This result suggests that the latter polymer with larger flexibility compared to the former polymer is more effective for the photoalignment.

• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.89-100
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• 2013

생물정보학의 다양한 이론적 내용과 계산적 방법들이 갈수록 전문화 되어짐에 따라 신약 개발, 신 물질 합성, 단백질의 구조 예측 등 다양한 분야에서 필요성이 커져가고 있다. 이 중 molecular docking 기술은 단백질과 특정 분자간의 결합 형태를 분자 모델링 기법을 통해 알아내는 방법이며 신약개발 연구에 큰 영향을 미치고 있다. Molecular docking을 통하여 분자간의 결합 형태를 예측하는 과정에서 Protein-ligand complex의 정확한 에너지 측정을 가능하게 하는 scoring function이 필요하다. 그런데 본 연구에서 사용한 B-Raf kinase protein 은 active site 부분에서 ligand와 receptor 간에 aromatic ring로 인한 ${\pi}-{\pi}$ interaction이 정확한 에너지 계산을 어렵게 한다. 이러한 ${\pi}-{\pi}$ interaction 부분의 에너지를 정확하게 계산하기 위해 양자역학 계산을 실시하였다. Active site 부분에서 ligand와 receptor에서 발생하는 각각 다른 5개의 ${\pi}-{\pi}$ interaction 구조를 준비하여 Gaussian을 통해 양자역학 에너지를 계산하였다. 그리고 이러한 결과 값들이 ligand의 활성 값과 어떤 상관관계를 갖는지 살펴보았다. 그 결과 ${\pi}-{\pi}$ interaction을 양자역학으로 계산한 값이 그렇지 않은 것보다 더 좋은 상관관계를 보여주었다. 이는 특별한 구조의 영향으로 ligand와 receptor 간의 결합에너지를 정확하게 계산하기 어려운 문제에서 양자역학을 적용할 경우 더욱 좋은 결과값을 얻을 수 있었다. 또한 이러한 데이터가 신 물질 개발이나 신약 개발 등의 다양한 분야에서 계산화학 방법이 신뢰성을 얻는데 도움 될 수 있다고 생각된다.

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.583-588
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• 2013

To determine alteration of immune responses during visceral larva migrans (VLM) caused by Toxascaris leonina at several time points, we experimentally infected mice with embryonated eggs of T. leonina and measured T-helper (Th) cell-related serial cytokine production after infection. At day 5 post infection (PI), most larvae were detected from the lungs, spleen, intestine, and muscle. Expression of thymic stromal lymphopoietin (TSLP) and CCL11 (eotaxin) showed a significant increase in most infected organs, except the intestine. However, expression of the CXCL1 (Gro-${\alpha}$) gene was most highly enhanced in the intestine at day 14 PI. Th1-related cytokine secretion of splenocytes showed increases at day 28 PI, and the level showed a decrease at day 42 PI. Th2-related cytokine secretion of splenocytes also showed an increase after infection; in particular, IL-5 level showed a significant increase at day 14 PI, and the level showed a decrease at day 28 PI. However, levels of Th17-related cytokines, IL-6 and IL-17A, showed gradual increases until day 42 PI. In conclusion, Th1, Th2, and Th17-related cytokine production might be important in immune responses against T. leonina VLM in experimental mice.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.109-119
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• 1993

To improve limitations of fuzzy PI controllers especially when applied to systems of order higher than one, we propose a fuzzy PI controller that takes out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the calculation of incremental control input as in the case of conventional fuzzy PI controllers. The structure of the proposed controller was motivated by the characteristics of fuzzy PI controller that it generally gives inevitable overshoot when one tries to reduce rise time of the response especially when a system of order higher than one is under consideration. Since the undesirable characteristics of the fuzzy PI controller is caused by integrator of the controller, even though the integrator is introduced to overcome steady state error of response, we propose a controller that fuzzily clears out integrated quantities according to situation to give reduced rise time as well as small overshoots. To show the usefulness of the proposed controller, it is applied in simulations to such systems as are difficult to stabilize or difficult to get satisfactory responses by conventional fuzzy PI controllers.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.97-105
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• 2017

Purpose: The purpose of this study was comparing the efficacy of passive irrigation (PI) and passive ultrasonic irrigation (PUI) for ability to remove debriment of canals. Materials and Methods: Mandibular premolars were decoronated and standardized to 16 mm length. After root canal enlargement and half separating longitudinally, standardized groove of 4 mm length, 0.2 mm width and 0.5 mm depth were formed on the dentin wall of one half. Three depressions in the canal wall of the opposite half, 0.3 mm in diameter and 0.5 mm in depth, were formed. After each groove and depression was filled with dentin debris, two sections of each half were reassembled using impression putty material. In group 1 the canals were irrigated with 2.5% NaOCl by PI. In group 2 the canals were irrigated with 2.5% NaOCl by PUI. Before and after root canal irrigation, the root canal wall of the section was taken with a microscope and a digital camera as images. The amount of dentin debris remaining in grooves and depressions was assessed using a scoring system. Results: There was no significant difference between PI and PUI except for the middle 1/3 of the root canal (P = 0.004). Conclusion: At the middle 1/3 of the root canal, PUI removed more dentine debris than PI. But the removal efficiency of dentin debris is not significantly different between the PUI and PI at the apical area of root canal in mandibular premolars.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.117-124
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• 1991

Soybean plants inoculated with Bradyrhizobium japonicum MN 110 were supplied with nutrient solutions containing 1.0, 0.25 and 0.5.nM-P to characterize the effect of externaI-P supply on the phosphorus status of nodules and on the P-uptake system of isolated bacteroids from nodules. After 48 days of growth, whole plant dry mass in the 0.25 and 0.05 mM-P treatments decreased significantly. The Pi concentrations in nodules were 4.1, 2.5 and 2.0 mM for 1.0, 0.25 and 0.05 mM-P treatments, respectively. The external-P supply did not significantly affect the distribution of phosphorus among inorganic phosphate(Pi), soluble organic-phosphorus(SOP) and insoluble organic-phosphorus(TOP) fractions in nodules. The Pi concentrations in young leaves of 0.25 and 0.05 mM-P plants were 33% and 20% , respectively, of those in young leaves of 1.0 mM-P plants and Pi concentrations in old leaves were only 16% and 7%, respectively, of those in old leaves of 1.0 mM-P plants. Phosphorus deficiency decreased the percentage of total leaf phosphorus in the Pi fraction and increased the percentage of total leaf phosphorus in the IOP fraction. The bacteroid number ranged from 0.87 to $1.30{\times}10^{11}$ Per GFW nodule regardless of external-P supply to the host Plants and Plant age, The P-uptake rates were the same (15-16 pmoles /min./$10^8$ bacteroids) for the bacteroids isolated from nodules of 1.0 mM-P and 0.05 mM-P plants. These results indicate that Pi concentrations in nodules of phosphorus-deficient plants are sufficient for proliferation of bacteroids and that the P-uptake system of bacteroids is in a repressed state even when host plant growth is severely restricted by phosphorus-deficiency stress.

• Journal of Chest Surgery
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• v.28 no.3
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• pp.221-227
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• 1995

Malignancy is one of the several exogenous and endogenous factors that increase serum alpha 1-PI. In fact, serum levels of alpha 1-PI were significantly elevated in the patients with the nonresectable bronchogenic cancer. the purpose of this work was to determine if the immediate postoperative change of serum alpha 1-PI level following tumor resection relates to the patient`s postoperative course. Clinical experimental study was carried out to investigate the postoperative changes of serum alpha 1-PI level following operation for 20 cases of bronchogenic cancer and 10 cases of control, nephrectomy patients Alpha 1-PI concentrations in serum was quantitated by use of radial immunodiffusion technique.The results were as follows ; Preoperative serum level of alpha 1-PI was significantly elevated in patients with bronchogenic cancers [p < 0.001 , when compared to normal control levels. Immediate postoperative serum alpha 1-PI level was significantly increased in patients with bronchogenic cancer [p < 0.05 , but slightly decreased at control groups. The peak serum level of alpha 1-PI was the postoperative three days, and then gradually decreased at the 5, 9, 14 days, but slightly elevated comparing to preoperative alpha 1-PI levels. Serum alpha 1-PI level in patients with adenocarcinoma was elevated, when compared to squamous cell carcinoma, but not significantly. According to the stages of the bronchogenic cancer, each levels of the serum alpha 1-PI were slightly different, but the whole postoperative changes were the general similarity. There were no significant difference in changes of the serum alpha 1-PI level, according to the operative procedures. As the alpha 1-PI is acute reactant, that it was required at the reoperative state of the bronchogenic cancer and rapid response, consumption or requirement were occurred, postoperatively. Therefore, alpha 1-PI can be perioperative indicator for the evaluation of the bronchogenic cancer.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1391-1396
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• 2014

In the present study, ten metal free non-linear optical (NLO) compounds have been designed. These compounds have designed by structural modification of (2-cyano-5-(4-(phenyl(4-vinylphenyl)amino)phenyl) penta-2,4-dienoic acid (TC4). Density functional theory was used for structure optimization and determination of photo-physical properties. These compounds contain triphenylamine as electron-donor and cyanoacrylic acid as acceptor. Five ${\pi}$-spacers are used to connect the donor and acceptor. Two auxiliary donors are also used to assist the donor. Results of this study indicate that stronger electron-donating auxiliary groups and longer ${\pi}$-conjugation enhance NLO response. Major absorption peaks of all systems were in the visible region. These absorption peaks are associated with the ${\pi}-{\pi}^*$ transitions of the entire molecule. From calculations it is clear that all system will be good NLO material. The present calculations will provide new ways for experimentalists to synthesize high-performance NLO material.