• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.96-105
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• 2002

A bacteriocin-producing strain identified as Pediococcus acidilactici was isolated from kimchi. The bacteriocin was identified to belong to the pediocin family and exhibited bactericidal activity against most Gram-positive bacteria as well as some Gram-negative bacteria. The bacteriocin was stable up to $80^{\circ}C with wide pH ranges (5.0-10.0). The bactericidal activity remained unchanged after treatment with nonproteolytic enzymes such as nuclease and ${\alpha}$-amylase, however, it was destroyed after treatment with protease. The bacteriocin was effectively extracted by the pH-mediated adsorption-desorption method and purified effectively by semi-preparative RP-HPLC. The molecular weight of the bacteriocin was 4,622, as determined by electrospray mass spectrometry. The amino acid sequence consisted of 44 amino acid residues with four cysteines. The high solubility and pH stability of the isolated pediocin provide definite advantages over nisin and other bacteriocins in regards to its potential applications.

• KSBB Journal
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• 제32권2호
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• pp.103-107
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• 2017

The effect of the trehalose incorporation on the biological membranes was investigated with respect to the phase of the membranes using the fluorescence intensity change. Spherical phospholipid bilayers, vesicles, were prepared only with the variation in the phase of each layer via a double emulsion technique. In the aqueous inside of the vesicles, 8-Aminonaphthalene-1,3,6-trisulfonic acid disodium salt(ANTS) was encapsulated. As a quencher, p-Xylene-bis(N-pyridinium bromide)(DPX) was included in the buffer where the vesicles were dispersed. The fluorescence scale was calibrated with the fluorescence of ANTS vesicles in p-Xylene-bis(N-pyridinium bromide)(DPX)-included-buffer taken as 100% fluorescence and the mixture of ANTS and DPX in the buffer as 0% fluorescence. Trehalose injection into the vesicle solution led the distortion of the membrane. It was found that the distortion was related to the phase of each layer the vesicle up on the ratio of trehalose to lipid. In the identical measurements at glucose, the behavior of the distortion was completely different from that of trehalose. These results seem to depend on the stability of the vesicles, due to the osmotic and volumetric effects on the headgroup packing disruption.

• Fisheries and Aquatic Sciences
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• 제11권3호
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• pp.159-165
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• 2008

Intertidal benthic algal communities on the shores of Gujido and Daeyeonpyeongdo islets, Korea, were examined in October 2007. At both sites, 45 seaweeds including 7 green, 6 brown and 32 red algae were identified. The number of species at Gujido(38 species) was 1.5 times higher than at Daeyeonpyeongdo(25 species), but seaweed coverage was very similar with about 20%. Dominant seaweeds in terms of coverage and importance value were Hildenbrandtia sp., Caulacanthus okamurae, Ulva pertusa, and Gelidium amansii at Gujido and U. pertusa, Hildenbrandtia sp., Gelidium divaricatum at Daeyeonpyeongdo. The vertical distribution pattern of the seaweeds was G. divaricatum-U. pertusa, Hildenbrandtia sp.-U. pertusa, Hildenbrandtia sp., Ishige okamurae from upper to lower intertidal zone but seaweed zonations were not observed on the Gujido rocky shore. At both sites, coarsely-branched forms were the dominant functional group in species number and percent cover(among benthic algal species). The rocky shores of the two sites were dominated by crustose coralline and green algae, whose presence generally results in decreased seaweed biodiversity and community stability. Therefore, the shores of the Yeonpyeongdo islets are of considerable environmental concern and should be monitored for seaweed species composition and community structure.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.485-490
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• 1994

A restriction endonuclease, PsyI, has been isolated from Pseudomonas syringae pv. pha- seolicola, and its catalytic properties have been studied. This enzyme was purified through strepto- mycin sulfate and ammonium sulfate fractionation, phosphocellulose Pll, DEAE-cellulose, hydroxy- apatite and Sephadex G-100 column chromatography. It's molecular weight was about 50,000 dalton as determined by 7.5% polyacrylamide gel electrophoresis containing 0.1% SDS. In catalytic proper- ties, PsyI shows stable at wide ranges of pH between 7.0 and 10.0, of temperature between 30$\circ$C and 37$\circ$C, and its thermal stability is between 25$\circ$C, and 45$\circ$C, at the presence Of 10 mM MgCl$_{2}$-PsyI essentially require Na salt for enzyme reaction, is rather inhibited in the high Na salt concent- ration. The presence of 2-mercaptoethanol is absolutely required for the enzyme activity. This endonuclease, PsyI was determined to be an isoschizomer of SalI from the results of the restriction mapping and DNA sequencing.

• 상하수도학회지
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• 제23권4호
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• pp.417-430
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• 2009

A BNR comprehensive performance evaluation (BNR CPE) system was established employing system-oriented evaluation methodology for biological nutrient removal (BNR) processes based on the CPE techniques developed by U.S. EPA for evaluation of conventional biological processes. The BNR CPE system applied to five domestic BNR plants adopting $A^2/O$ process confirmed that all target plants except the smallest one had not any serious defective performance and process stability was enhanced with increasing plant size. The system also clearly verified relatively poor performances in anoxic reactors without exception mainly due to influent carbon limit rather than functional defect. Consistent good performances were confirmed even during both winter season and wet weather generally known to be difficult to achieve satisfactory removals. Presentation of evaluation results by modified radar chart system simplified and clarified the evaluation and analysis procedures. The BNR CPE system could not only discover readily the causes of present and prospective poor performances but also facilitate the suggestion of their optimization options. Mutual effect and cause-and-effect among operation parameters and unit processes were also found easily using the evaluation system. The system justified that the adverse effect of defective operating parameters could be compensated by other favorable parameters, especially in anaerobic and anoxic reactors as well as during the winter season.

• 한국식품과학회지
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• 제17권6호
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• pp.490-494
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• 1985

물에 녹지않는 기질을 사용할 수 있고, 다시 효소를 회수하여 다음에 사용하고자 할때 효소와 기질등 과의 분리등 여러 가지 장점이 있는 2상계(이상계(二相界))를 사용하여 Rhizopus arrhizus의 리파제에 의한 에스테르 교환반응을 위한 기본 실험으로써 물에 녹지 않는 각종 유기용매 중에서 이 반응을 위한 가장 좋은 유기용매를 고르고자 유기용매가 리파제의 안정도와 활성도에 미치는 영향을 보았다. 이실험에서 사용된 유기용매는 n-hexane, n-heptane, n-octane, isooctane, cyclohexane등 5개의 탄화수소와 doethylether, diisopropylether, di-n-butylether등 3개의 에테르이다. 실험 결과 diiso-propylether와 isooctane 이 다른 유기용매에 비해 월등히 2상계를 이용한 에스테르 교환 반응에 좋은 용매임을 알았다.

• 폴리머
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• 제31권5호
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• pp.379-384
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• 2007

본 연구는 열안정성을 향상시킨 무기나노 분말충전 나노복합재료를 우레탄 중합방법으로 제조하였다. 나노복합재료의 구조와 표면 특성은 XRD와 FT-IR을 통하여 알아보았고, 열안정성은 TGA와 DSC를 통하여 알아보았으며, SEM을 이용하여 복합재료의 모폴로지를 관찰하였다. 복합재료의 기계적 물성은 UTM을 사용하여 측정하였다. 실험 결과, MMT를 충전한 나노복합재료의 층간거리가 $7.5{\AA}$ 증가하였고, Silica 내 Si-O기에 의해 $1038cm^{-1}$에서 새로운 피크가 나타났다. 또한 열안정성과 기계적 물성도 폴리우레탄 매트릭스보다 향상된 것을 확인할 수 있었다.

• 한국식품영양과학회지
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• 제28권1호
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• pp.40-46
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• 1999

Microbiological quality of commercial white ginseng was examined, together with investigation on its water absorption pattern and radiosensitivity of molds isolated from the samples. Comparative effects of phosphine fumigation and gamma irradiation on microbial control and disinfestation of the samples packed in a commercial laminated film and stored for six months at ambient(20oC, 70% RH) and accelerated(40oC, 90% RH) conditions were studied. Commercial white ginseng was contaminated with coliforms by 103~104CFU/g and molds by 102~104CFU/g and thus decontamination process was required for hygienic quality and storage stability. Phosphine fumigation showed no sterilizing effects on microbes contaminated, while gamma irradiation at around 5kGy was effective for decontaminating microorganisms, showing D10 values of 0.48~0.60kGy for isolated molds. Even though the storage insects, Plodia interpuctella Hubner and Lasioderma serricorne(cigarette beetle) were easily destroyed by phosphine fumigation, gamma irradiation less than 5kGy was found effective for both purposes to improve biological quality of stored white ginseng, thereby extending the storage life of packed samples resulting from increased critical moisture content by about 1%(Aw 0.76).

• Journal of Korean Biological Nursing Science
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• 제17권2호
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• pp.179-187
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• 2015

Purpose: This study was done to evaluate the effects of a recreation therapy program on burn rehabilitation patients to determine if the program is an effective nursing intervention which can affect mental health problems and heart rate variability. Methods: Subjects were 54 hospitalized burn rehabilitation patients (25 in the control group, 29 in the experimental group). The experimental group participated 6 times in a recreation therapy program led by a qualified instructor. Brief symptoms inventory-18 (somatization, anxiety, depression) questionnaire, and heart rate variability were checked before and after the recreation therapy program. Results: The mental health scale showed significant differences in somatization (p<.001), anxiety (p<.001) and depression (p<.001). There was no significant difference in heart rate variability (autonomic activity, autonomic balance, stress resistance, stress parameter and fatigue, mean heart rate, electro-cardiac stability). Conclusion: The findings from this study suggest that a recreation therapy program is an effective nursing intervention to decrease the level of mental health problems of burn rehabilitation patients. However, a subsequent study is needed to develop an intervention program that will induce the effect of physiological parameters like heart rate variability (HRV).

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1579-1584
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• 2003

An integrated gold microdisk electrode was constructed and modified with metal-porphyrin or metal-phthalocyanines for NO determination in biological media. Microanalysis of NO using square wave anodic stripping voltammetry in $1\;{\times}\;10^{-2}$ M $HClO_4$ was optimal when the accumulation potential was 0.1 V, frequency 100 Hz, and the scan rate was 200 mV/s. When the electrode was modified with metal-porphyrin or metal-phthalocyanines, the anodic peak currents of NO increased due to the catalytic oxidation of NO. In case of Fe(II)-phthalocyanine modified electrode, the peak currents remarkably increased and the sensitivity was high. The calibration curve had good linearity in the range from $3.6\;{\times}\;10^{-5}$ M to $7.2\;{\times}\;10^{-7}$ M, and the detection limit was $5.7\;{\times}\;10^{-7}$ M. For the structural stability and increased sensitivity, Fe(II)-phthalocyanine modified gold microdisk electrode coated with Nafion was applied to determination of NO released from cultured macrophase.