• Korean Chemical Engineering Research
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• 제55권2호
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• pp.225-229
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• 2017

최근 약물전달시스템으로 널리 주목받고 있는 dextran의 미립자는 초임계 반용매 공정을 통해 얻을 수 있다. 초임계 반용매(SAS) 공정에서는 DMSO (dimethyl sulfoxide)에 용해되어 있는 dextran이 반용매인 초임계 $CO_2$의 첨가에 의한 재결정으로 얻어진다. 본 연구에서는 이 공정의 적절한 운전조건을 제시하기 위하여 가변부피 셀을 이용하여 cloud point를 측정함으로써 Dexran/DMSO/$CO_2$의 상거동을 관찰하였다 실험결과로부터 dextran 미립자 제조를 위한 초임계 반용매 공정의 적절한 온도(300.15 K~330.15 K), 압력(90 bar~130 bar), 용질의 농도(5 mg/ml~20 mg/ml)의 범위를 결정하였다.

• The Korean Journal of Pain
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• 제32권2호
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• pp.87-96
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• 2019

Background: This study was performed in order to examine the effect of intrathecal sec-O-glucosylhamaudol (SOG), an extract from the root of the Peucedanum japonicum Thunb., on incisional pain in a rat model. Methods: The intrathecal catheter was inserted in male Sprague-Dawley rats (n = 55). The postoperative pain model was made and paw withdrawal thresholds (PWTs) were evaluated. Rats were randomly treated with a vehicle (70% dimethyl sulfoxide) and SOG ($10{\mu}g$, $30{\mu}g$, $100{\mu}g$, and $300{\mu}g$) intrathecally, and PWT was observed for four hours. Dose-responsiveness and ED50 values were calculated. Naloxone was administered 10 min prior to treatment of SOG $300{\mu}g$ in order to assess the involvement of SOG with an opioid receptor. The protein levels of the ${\delta}$-opioid receptor, ${\kappa}$-opioid receptor, and ${\mu}$-opioid receptor (MOR) were analyzed by Western blotting of the spinal cord. Results: Intrathecal SOG significantly increased PWT in a dose-dependent manner. Maximum effects were achieved at a dose of $300{\mu}g$ at 60 min after SOG administration, and the maximal possible effect was 85.35% at that time. The medial effective dose of intrathecal SOG was $191.3{\mu}g$ (95% confidence interval, 102.3-357.8). The antinociceptive effects of SOG ($300{\mu}g$) were significantly reverted until 60 min by naloxone. The protein levels of MOR were decreased by administration of SOG. Conclusions: Intrathecal SOG showed a significant antinociceptive effect on the postoperative pain model and reverted by naloxone. The expression of MOR were changed by SOG. The effects of SOG seem to involve the MOR.

• Restorative Dentistry and Endodontics
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• 제48권1호
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• pp.8.1-8.8
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• 2023

Objectives: This study was designed to evaluate the parameters of bonding performance to root dentin, including push-out bond strength and dentinal tubular biomineralization, of a hydraulic bioceramic root-end filling material premixed with dimethyl sulfoxide (Endocem MTA Premixed) in comparison to a conventional powder-liquid-type cement (ProRoot MTA). Materials and Methods: The root canal of a single-rooted premolar was filled with either ProRoot MTA or Endocem MTA Premixed (n = 15). A slice of dentin was obtained from each root. Using the sliced specimen, the push-out bond strength was measured, and the failure pattern was observed under a stereomicroscope. The apical segment was divided into halves; the split surface was observed under a scanning electron microscope, and intratubular biomineralization was examined by observing the precipitates formed in the dentinal tubule. Then, the chemical characteristics of the precipitates were evaluated with energy-dispersive X-ray spectroscopic (EDS) analysis. The data were analyzed using the Student's t-test followed by the Mann-Whitney U test (p < 0.05). Results: No significant difference was found between the 2 tested groups in push-out bond strength, and cohesive failure was the predominant failure type. In both groups, flake-shaped precipitates were observed along dentinal tubules. The EDS analysis indicated that the mass percentage of calcium and phosphorus in the precipitate was similar to that found in hydroxyapatite. Conclusions: Regarding bonding to root dentin, Endocem MTA Premixed may have potential for use as an acceptable root-end filling material.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2683-2688
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• 2012

The position of the thermodynamic equilibrium for reverse thermochromic spiropyran 6-carboxylates (SP-COOHs) was easily determined in aqueous binary mixtures, such as water-methanol, water-acetonitrile and water-dimethyl sulfoxide. The existence of more than one type of interconvertible species of the ring-opened form of SP-COOH in aqueous binary solvents enables us to evaluate the molar extinction coefficients of the ring-opened species of SP-COOH and to obtain the thermodynamic parameters.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1329-1332
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• 2014

The kinetic studies on the reactions of O,O-diethyl Z-S-aryl phosphorothioates with X-pyridines have been carried out in dimethyl sulfoxide. The free energy correlations with X in the nucleophiles are biphasic concave upwards with a break point at X = H, while those for substituent Z variations in the leaving groups are linear. The negative sign of ${\rho}_{XZ}$ implies that the reaction proceeds through a concerted mechanism for both the strongly and weakly basic pyridines. The biphasic concave upward free energy relationships with X are rationalized by a change in the nucleophilic attacking direction from frontside with the strongly basic pyridines to backside with the weakly basic pyridines.

• 한국진공학회지
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• 제10권1호
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• pp.57-60
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• 2001

우리는 술폭시화디메틸에 $_CdCl2$와 S를 포함하는 전해질로부터 양극산화된 알루미나 막의 세공 안으로 반도체를 직접 전착하여 5$\mu\textrm{m}$까지의 길이와 20nm의 작은 직경의 균등한 CdS 나노선 배열을 제조하였다. 나노선 배열은 주사전자현미경법과 X-선회절에 의해 연구되었다. 전착된 물질은 주로 (100) 우선방위를 지닌 육방정계 CdS로 이루어져 있다.

• 한국식품조리과학회지
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• 제10권4호
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• pp.376-380
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• 1994

마늘의 alliinase를 ammonium sulfate 분획과 hydroxylapatite chromatography, concanavalin A-Sepharose affinity chromatography에 의해 정제하여, 23% 의 회수율과 7.6배 정제도를 나타내었다(specific activity 116.6 units/mg). SDS-polyacrylamide gel electrophoresis에서 단일 band를 나타내므로 순수한 aliinase 로 추측되며 이 효소의 분자량은 42K 로 추정된다. 기질로서 S-ethyl-L-cysteine sulfoxide를 사용한 이 효소의 $V_max$값은 2.27${\mu}$monl/mg.min이고 $K_m$은 1O mM이다 . 정제효소의 optimum pH는 6.5 phosphate buffer이며, 40$^{\circ}C$에서 최대활성을 나타내었다. Activation energy value($E^*$)는 4.6Kcal/mole로 추정된다.

• Journal of Photoscience
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• 제10권1호
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• pp.1-7
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• 2003

The results of recent work on the dye-sensitized photooxygenation of sulfides is discussed. In the case of dialkyl sulfides, the weakly bonded adduct initially formed with singlet oxygen (the persulfoxide) decays unproductively unless protonation by an acid (an alcohol or a carboxylic acid) facilitates its conversion to the sulfoxide. The effect is proportional to the strength of the acid (eg., less than 0.1 % chloroacetic acid in benzene is sufficient for maximal efficiency) and corresponds to general acid catalysis, suggesting that protonation of the persulfoxide occurs. On the other hand, with sulfides possessing an activated hydrogen in ${\alpha}$ position (eg., benzyl and allyl sulfides), hydrogen transfer becomes an efficient process in aprotic media and yields a S-hydroperoxysulfoniumm ylide, possibly arising from a conformation of the persulfoxide that is different from the one protonated in the presence of acids. Calculations on some substituted sulfides support this hypothesis. This process, which leads to C-S bond fragmentation with formation of an aldehyde, may be viewed as a general method for the preparation of aryl and heteroaryl aldehydes. In this effort, mechanistic studies offered new hints on the structure of the intermediate persulfoxide.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.322-328
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• 2000

To screen agent for the treat-ment of Alzhimers Disease several strains of bacteria producing acetylcholinesterase inhibitor ware isolated from soil. Strain 960903 showed strong acetylcholinesteras inhibitory activity and low butyrylcholinesterse inhibitory activity. The strain 960903 was identified as Pseudomonas sp. Acetylcholinesterase inhibitor ws highly achieved in fermentation medium containing soluble starch 3.0%, glycerol 1.0%, pharmamedia 0.5%, KCI 0.3%, $CaCO_3$ 0.2%, MgS $O_4$..$7H_2$O 0.05%, $KH_2$$PO_4$ 0.05%(pH6.5) at $30^{\circ}C$ for 4 days. Acetylcholinesterase inhibitor was purified by Diaion WA-30($OH^{-}$) column charomatography and cellulose column chromatography. Acetylcholinesterase inhibi-tor showd the maximum wavelength at 205 nm and was soluble in water, acetic acid, ethanol, methanol and dime-thyl sulfoxide. The concentration of 50% inhibition($IC_{50}$) of inhibitor against acetylcholinesterase was 25$\mu\textrm{g}$/ml. The inhibitor was inactivated on heating ar $100^{\circ}C$ fro 15 min and more stable in acidic region than alkaline region.n.

• Advances in materials Research
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• 제3권2호
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• pp.117-128
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• 2014

Processable conducting polyaniline derivative with free amine functional groups was successfully synthesized from the monomer o-phenylenediamine in aqueous hydrochloric acid medium using ammonium persulfate as an oxidative initiator. The synthesized poly(o-phenylenediamine) (PoPD) in critical condition was found to be completely soluble in common organic solvents like dimethyl sulfoxide, N,N-dimethyl formamide etc. From the intrinsic viscosity measurement, the optimum condition for the polymerization was established. The polymer was characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy ($^1HNMR$) and thermogravimetric (TGA) analyses. The weight average molecular weights of the synthesized polymers were determined by the dynamic light scattering (DLS) method. From the spectroscopic analysis the structure was found to resemble that of polyaniline derivative with free amine functional groups attached to ortho/meta position in the phenyl ring. However, very little ladder unit was also present with in the polymer chain. The moderate thermal stability of the synthesized polymer could be found from the TGA analysis. The average DC conductivity of $2.8{\times}10^{-4}S/cm$ was observed for the synthesized polymer pellet after doping with hydrochloric acid.