• 약학회지
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• 제41권6호
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• pp.692-697
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• 1997

Creatine and 3,4-Dimethylhippuric acid (3,4-DMHA), a glycine conjugate of 1,2,4-trimethyl-benzene (1,2,4-TMB) were determined in the urine of workers exposed to 1,2,4-TMB vapor. The best condition for the simultaneous determination of 3,4-DMHA and creatine by high performance liquid chromatography was obtained by reverse phase $C_{18}$ column (4.6${\times}$150mm, 5${\mu}m$) as stationary phase and 20% acetonitrile in 20mM phosphate buffer (pH 3.0) containing 4mM sodium octylsulfate(SOS)as mobile phase. The recovery of 3,4-DMHA spiked to blank urine in the range of 1~5${\mu}g$/ml was about 96%. The concentration of urinary 3,4-DMHA of workers had a positive correlation with the environmental level of 1,2,4-TMB (r=0.866). The data suggest that urinary 3,4-DMHA concentration is a useful biological index for 1,2,4-TMB exposure.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.547-551
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• 2003

In the present work, the interaction of three water soluble porphyrins, tetra(p-trimethyle) ammonium phenyl porphyrin iodide (TAPP) as a cationic porphyrin, tetra sodium meso-tetrakis (p-sulphonato phenyle) porphyrin (TSPP) as an anionic porphyrin and manganese tetrakis (p-sulphonato phenyl) porphinato acetate (MnTSPP) as a metal porphyrin, with histone H₂B have been studied by isothermal titration microcalorimetry at 8 mM phosphate buffer, pH 6.8 and 27 °C. The values of binding constant, entropy, enthalpy and Gibbs free energy changes for binding of the first MnTSPP, and first and second TSPP and TAPP molecules were estimated from microcalorimetric data analysis. The results represent that the process is both entropy and enthalpy driven and histone induces self-aggregation of the porphyrins. The results indicate that both columbic and hydrophobic interactions act as self-aggregation driving forces for the formation of aggregates around histone.

• Macromolecular Research
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• 제11권5호
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• pp.382-386
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• 2003

Reductive amination of N-succinyl-chitosan (1) and lactose using sodium cyanoborohydride in 1/15 M phosphate buffer (pH 6.0) for 6 d was suitable for the preparation of lactosaminated N-succinyl-chitosan (2). At 8, 24 and 48 h after i.v. administration of fluorescently labeled 1 (1') or 2 (2'), Peyer's patch, mesenteric lymph nodes, testes, prostate, preputial grand, intestine (small intestine plus cecum), femoral muscle, backbone and peritoneum were taken. Peyer's patch and mesenteric lymph nodes were put together as lymph nodes. Over 10% of dose/g tissue was distributed to the prostate and lymph nodes at 48 h post-administration in both l' and 2'.2' was easily distributed into not only the liver but also prostate, intestine, preputial gland and lymph nodes. Although galactose receptors are known to exist not only on the liver parenchymal cells but also on prostate and testes, the selective distribution of 2' into the prostate and the testes were not observed clearly. This study suggested that 1 and 2 should have possibilities for both the prevention and cure of lymph node metastasis as drug carriers.

• KSBB Journal
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• 제15권5호
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• pp.452-457
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• 2000

Buffer의 특성에 맞는 체류인자에 관한 모텔식을 얻기 위 해서는 buffer 9} 양이온의 농도에 관한 관련식을 실험으로 결 정해야 한다 또한 model 식에서 비이온과 음이온의 체류인 자를 나타내는 ko와 k의 값이 일정한 경향을 나타내고 있기 때문에 buffer의 농도와 modifier의 농도를 동시에 고려한 model 식이 가능하게 된다. 본 연구에서 제안한 모델식을 이용하여 임의의 buffer의 농도에 따른 시료의 체류시간을 예측할 수 있다. 이러한 모텔식을 이용하여 buffer를 이 용한 RP-HPLC의 분석 및 분리조건을 예측할 수 있고 시행 오차적인 방법보다 빠른 시간 내에 최적의 분석 및 분리조건 을 얻을 수 있다

• 한국세라믹학회지
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• 제37권7호
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• pp.693-699
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• 2000

Casting behavior of Zr(Y,Ce)O2 TZP/Mullite suspension during pressure filtration was investigated to prepare multi-layered Functionally Gradient Materials(FGM). The dispersion stabilities of each layer suspension were investigated by examination of zeta potential and viscosity. The each suspensions with 20 vol.% solid loading and 100 첸 of viscosity was prepared after fix of the dispersing agent (Sodium hexa-meta phosphate) and the binder (Hydroxyethyl cellulose), and then the cakes were formed at the 2.5 MPa~10.0MPa pressure range. The cake thickness of all suspensions was increased with the square root of time at the constant pressure, and the relations between filtration pressure(P)a nd dehydration rate (Q=dh/dt) showed that the flows of filtrates in the consolidated layers were laminar. The permeabilities were nearly constant during filtration, and kozeny constants(Kc) of the suspensions were 4.8~6.7. These valumes were seen as close to 5, which might be homogeneous particle packing during filtration. On the basis of those data, the multi layered compaction with 9 mm thickness and 52.5% green density was prepared by continuous pressure filtration.

• 한국응용과학기술학회지
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• 제13권1호
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• pp.11-19
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• 1996

The liposomes have been developed in many drugs and cosmetics fields. The liposomes prepared with main compounds of the intercellular lipids and lecithin. Amphiphile nonionic surfactants used for (PEG) n-sitosterol(n=5), diethanolamine cetylphosphate. The effect of gelation for liposomes have been on swelling reaction which have been mixed phospholipid with polyol-group at the high temperature. There were very good encapsulated properties of the active ingredients whether hydrophilic-group(magnesium ascorbyl phosphate, allantoin, sodium hyaluronate) and hydrophobic-group(vitamin-E acetate, vitamin-A palmitate). Optimum condition of liposomes were passed five times in the microfluidizer(700bar), wetting reaction temperature was at $95{\pm}5^{\circ}C$ for a hours. Particle size distribution of the vesicles should be within range 50-560nm(mean 200nm). The stability of liposomes for the course of time was stabilized for six months at $45^{\circ}C$. Application of the cosmetic was prepared moisturizing cream with liposomes of the phospholipid base.

• 한국축산식품학회지
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• 제42권2호
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• pp.252-265
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• 2022

Kocuria salsicia can survive in extreme environments and cause infections, including catheter-related bacteremia, in humans. Here, we investigated and evaluated the characteristics of nine K. salsicia strains (KS1-KS9) isolated from cheese brine from a farmstead cheese-manufacturing plant in Korea from June to December, 2020. Staphylococcus aureus American Type Culture Collection (ATCC) 29213 was used as a positive control in the growth curve analysis and biofilm-formation assays. All K. salsicia isolates showed growth at 15% salt concentration and temperatures of 15℃, 25℃, 30℃, 37℃, and 42℃. KS6 and KS8 showed growth at 5℃, suggesting that they are potential psychrotrophs. In the biofilm-formation analysis via crystal violet staining, KS6 exhibited the highest biofilm-forming ability at various temperatures and media [phosphate buffered saline, nutrient broth (NB), and NB containing 15% sodium chloride]. At 25℃ and 30℃, KS3, KS6, and KS8 showed higher biofilm-forming ability than S. aureus ATCC 29213. The antimicrobial resistance of the isolates was evaluated using the VITEK^® 2 system; most isolates were resistant to marbofloxacin and nitrofurantoin (both 9/9, 100%), followed by enrofloxacin (7/9, 77.8%). Five of the nine isolates (5/9, 55.6%) showed multidrug resistance. Our study reports the abilities of K. salsicia to grow in the presence of high salt concentrations and at relatively low temperatures, along with its multidrug resistance and tendency to form biofilms.

• Elastomers and Composites
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• 제59권1호
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• pp.1-7
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• 2024

Nanorod graphitic carbon nitride (g-C₃N₄) was synthesized by reacting melamine (C₃H₆N₆) with trithiocyanuric acid (C₃H₃N₃S₃) in distilled water for 10 h at room temperature. The resulting mixture was calcined at 550℃ for 2 h in an electric furnace under an air atmosphere. Nanorod g-C₃N₄/Ag₃PO₄ composites were prepared by adding nanorod graphitic carbon nitride (g-C₃N₄) powder, silver nitrate (AgNO₃), ammonia (NH₃·H₂O, 25.0-30.0%), and sodium hydrogen phosphate (Na₃HPO₄) to distilled water. The samples were characterized via X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The photocatalytic activities of the nanorod g-C₃N₄/Ag₃PO₄ composites were demonstrated via the degradation of organic dyes, such as methylene blue and methyl orange, under blue light-emitting diode irradiation and evaluated using UV-vis spectrophotometry.

• 방사성폐기물학회지
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• 제3권1호
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• pp.57-65
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• 2005

본 연구는 사용 후 핵연료의 금속전환 공정에서 발생되는 폐용융염을 고형화하는 방법으로 GRSS(Gel-Route Slabilization/Solidifcation)개념을 이용한 전처 리법을 제안하였다. Sodium silicate와 H3p04로 구성된 물질계에서는 SiO$_2$에 의해 형성되는 반응모듈 내에서 휘발성 핵종은 열적으로 안정한 화합물로 전환된다. 얻어진 생성물은 붕규산 유리매질과의 반응을 통하여 Li는 Li$_{3}$PO$\_4$ 형태로 유지되며 Cs 및 Sr은 유리매질내에 포용될 수 있다. 또한 sodium silicate, H$_{3}$PO$_4$ 및 ZrCl$_4$로 이루어진 물질계를 이용하여 내구성이 우수한 WZP 세라믹 고화매질을 합성하였다. $700^{circ}C$이상에서 NZP구조가 형성되며, Cs가 Li보다 우선하여 NZP구조를 형성하였다. 이상의 결과로부터, GRSS를 이용한 폐용융염의 전처리는 단순한 공정과 열적 안정성을 통하여 검증된 고화매질로 고형화가 가능토록하는 유효한 접근법이라 할 수 있으며, 수화학적 안정성의 검증을 통하여 ANL의 제올라이트를 이용한 고화법에 대한 대안이 될 것으로 기대된다.

• 분석과학
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• 제29권5호
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• pp.234-241
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• 2016

비글견 혈장 중 arsenite (As(III)), arsenate (As(V)), dimethylarsinic acid (DMA)와 monomethylarsonic acid (MMA)를 정량하기 위한 분석법의 유효성을 검증하기 위하여 본 연구를 수행하였다. 비소를 종 분리하기 위하여 액체크로마토그래피 (HPLC) 와 결합된 유도결합 플라즈마 질량분석기 (ICP/MS) 를 사용하였으며, 비소를 정량하는 검출기에서 스펙트럼 간섭을 최소화하기 위하여 산소(O₂)를 반응기체로 하는 DRC (dynamic reaction cell)모드를 이용하였다. 분석법의 유효성을 검증하는 항목으로 선택성, 직선성, 정확성, 정밀성, 생체시료효과, 회수율, 시스템 적합성, 희석의 타당성과 안정성 실험을 실시하였다. 선택성의 결과 정량에 방해되는 피크는 없는 것으로 확인 되었으며, 정량범위에서 평균 상관계수가 0.999 이상의 좋은 직선성을 보였다. 최저정량한계는 As(III), As(V)와 DMA는 5 ng/mL이였고, MMA는 20 ng/mL이였다. 생체시료의 영향, 시스템 적합성 과 회수율 항목을 통해 정량성에 대한 영향이 없음을 확인하여 비글견 혈장 중 비소 종을 분리하여 정량하는 분석법의 유효성을 검증하였다. 따라서 본 연구에서 제시한 분석법은 건강에 유해한 비소의 농도를 정량 및 평가하는데 적용될 것이다.