• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.286-290
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• 2010

The reaction of carboxylic acid derivatives such as esters, acid chlorides and acid anhydrides with alkynyl lithiums in the presence of lithium morpholinide and $BF_3{\cdot}OEt_2$ gave alkynyl ketones in good yield (73-96%).

• 한국동물학회지
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• 제38권4호
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• pp.483-489
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• 1995

많은 세포와 조직에서 분화 조절물질로 알려져 있는 비타민 A의 대사산물인 rectinoic acid(RA)가 배양 계배 근원세포의 성장과 분화에 미치는 영향을 조사하였다. RA가 처리된 세포는 그 농도가 증가함에 따라 융합 억제 효과도 증가함을 보였고, 배양액으로부터 RA를 제거해 주면 근원세포의 융합이 재개되는 것으로 보아, RA는 근원세포의 융합을 가역적으로 억제함을 알 수 있었다. 그러나 이미 최종 분화 단계에 들어선 세포에서는 융합 억제 효과를 보이지 않아, RA의 효과는 분화 단계에 따라 특이적으로 작용함을 보여준다. 융합 억제 효과에도 불구하고, RA는 근원세포의 융합 전단계인 방추형으로 신장하는 것과 그들이 가상의 축을 따라 배열하는 데는 영향을 주지 않았다. 또한 세포의 증식과 creatine kimase, tropomyosin과 같은 근특이 단백질의 축적에도 큰 영향을 주지 않았다. 한편, 근원세포는 융합하기 전에 필수적으로 fibronectin의 감소를 억제함을 알 수 있었다. 이상의 결과로 RA는 배양 근원세포의 융합만을 특이하게 억제하는 물질이며, 그 작용은 fibronectin의 감소를 방해하는 것과 밀접한 관계가 있는 것으로 사료된다.

• Journal of Pharmaceutical Investigation
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• 제41권6호
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• pp.363-369
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• 2011

In this study, we demonstrated the release behavior of carvedilol with the content of polyvinylpyrrolidone K-30 (PVP K-30) and the effect of citric acid and fumaric acid as acidifiers on the release behavior of drug. In addition, it tries to inquire into the release behavior difference of the carvedilol according to the manufacturing method. The release behavior of the tablets was compared with Dilatrand$^{(R)}$ in the simulated gastric fluid (pH1.2). Differential scanning calorimeter (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were characterized for the physicochemical properties of the tablets. In case of mixing the carvedilol and PVP K-30, in case the ratio of the carvedilol and PVP K-30 was 1:5, the release behavior was the highest among. As well as the dissolution rate of tablets manufactured by lyophilization and rotary evaporator was higher than physical mixture. The dissolution rate of containing acidifiers was more improved. But, rather the excessive amount of the acidifier addition reduced the dissolution rate.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3509-3513
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• 2014

Phospholipase D (PLD) catalyzed the generation of phosphatidic acid (PA) from phosphatidylcholine (PC) at the outer layer of the vesicles prepared through layer by layer via a double emulsion technique. The generation induced a curvature change in the vesicles, which eventually led them to fuse each other. The ratio of two-fatty-acid-tail ethanolamine (PE) to one-fatty-acid-tail ethanolamine (PE) was found to acquire the condition where the mixed-phospholipid vesicles were stable identically with pure two-fatty-acid-tail PC. The effect of the outer-layer mixture on the PLD-induced vesicle fusion was investigated using the fluorescence intensity change. 8-Aminonaph-thalene-1,3,6-trisulfonic acid disodium salt (ANTS) and p-Xylene-bis(N-pyridinium bromide) (DPX) were encapsulated in the vesicles, respectively, for the quantification of the fusion. The fluorescence scale was calibrated with the fluorescence of a 1/1 mixture of ANTS and DPX vesicles in NaCl buffer taken as 100% fluorescence (0% fusion) and the vesicles containing both ANTS and DPX as 0% fluorescence (100% fusion), considering the leakage into the medium studied directly in a separate experiment using vesicles containing both ANTS and DPX. The fusion data for each composition were acquired with the subtraction of the leakage from the quenching. From the monitoring, the vesicle fusion caused by the PLD reaction seems dominantly to occur rather than the vesicle lysis, because the composition effect on the fusion was observed identically with that on the change in the vesicle structure. Furthermore, the diameter measurements also support the fusion dominancy.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1449-1450
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• 2008

• Journal of Microbiology
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• 제34권1호
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• pp.7-14
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• 1996

Teh baculovirus gp64 glycoprotein is a major component of the envelope of budded virus (BV) and has been shown that it plays an essential role in the infection process, especially virus-cell membrane fusion. We have cloned Autographa californica Nuclear Polyhedrosis Virus (AcNPV) gp64 protein were examined for membrane fusion activity by using a synchtium formation assay under various conditions. The optimal conditions required for inducing membrane fusion are 1) form pH 4.0 to 4.8 2) 15 min exposure of cells to acidic pH 3) at least 1 .mu.g of gp64 cloned plasmid DNA per 3 * 10$^{6}$ cells 4) and an exposure of cells to acidic pH at 72 h post-transfection. In order to investigate the role of hydrophobicity of the gp64 glycoprotein for the membrane fusion, the two leucine residues (amino acid position at 229 and 230) within hydrophobic region I were substituted to alanine by PCR-derived site-directed mutagenisis and the membrane fusion activity of the mutant was anlaysed. The gp64 glycoprotein carrying double alamine substitution mutation showed no significant difference in fusion activity. This result suggested that minor changes in hydrophobicity at the amino acid position 229 and 230 does not affect the acid-induced membrane fusion activity of the gp64 glycoprotein.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.728-730
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• 2012

• 한국물환경학회지
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• 제28권3호
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• pp.367-374
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• 2012

A flotation process has a shorter processing time and needs less space than a sedimentation process. Dissolved air flotation process (DAF) is an efficient flotation method and used in a conventional wastewater treatment process. However, DAF requires the circulation of water containing compressed air and requires expensive installation and operation cost. Plasma Air Flotation (PAF) process is able to float flocs by micro bubbles generated from underwater plasma without the circulation of bubbly water and additional saturators. Therefore, PAF can be an alternative solution overcoming economic barriers. In this study, Humic acid removal efficiency by PAF process was compared with that of sedimentation process. 44.67% and 87.3% reduction rate based on UV 254 absorbance has been measured in sedimentation and PAF respectively. In particular, PAF in the flocculation zone can dramatically remove humic acid from water. In flocculation zone, PAF can separate organic matters but sedimentation cannot.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3618-3624
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• 2012

Photodissociation dynamics of propiolic acid ($HC{\equiv}C-COOH$) at 212 nm in the gas phase was investigated by measuring rotationally resolved laser-induced fluorescence spectra of OH ($^2{\Pi}$) radicals exclusively produced in the ground electronic state. From the spectra, internal energies of OH and total translational energy of products were determined. The electronic transition at 212 nm responsible for OH dissociation was assigned as the ${\pi}_{C{\equiv}C}{\rightarrow}{\pi}^*{_{C=O}}$ transition by time-dependent density functional theory calculations. Potential energy surfaces of both the ground and electronically excited states were obtained employing quantum chemical calculations. It was suggested that the dissociation of OH from propiolic acid excited at 212 nm should take place along the $S_1/T_1$ potential energy surfaces after internal conversion and/or intersystem crossing from the initially populated $S_2$ state based upon the potential energy calculations and model calculations for energy partitioning of the available energy among products.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1592-1594
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• 2013