• Journal of Biosystems Engineering
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• 제43권4호
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• pp.394-400
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• 2018

Purpose: This research evaluated five types of nanoparticles to develop a surface-enhanced Raman spectroscopy (SERS) method for the rapid detection of two Bacillus species (Bacillus cereus and Bacillus thuringiensis) that are commonly found on fresh produce, which can cause food poisoning. Methods: Bacterial concentrations were adjusted to a constant turbidity, and a total of $30{\mu}L$ of each Bacillus cell suspension was prepared for each nanoparticle. A point-scan Raman system with laser light source of wavelength 785 nm was used to obtain SERS data. Results: There was no qualitative difference in the SERS data of B. cereus and B. thuringiensis for any of the five nanoparticles. Three gold nanoparticles, stabilized in either citrate buffer or ethanol, showed subtle differences in Raman intensities of two Bacillus species at $877.7cm^{-1}$. Conclusions: Among the three types of nanoparticles, the gold nanoparticles stabilized in citrate buffer showed the lowest standard deviation, followed by gold nanoparticles stabilized in ethanol. This result supports the potential application of gold nanoparticles for SERS-based detection of B. cereus and B. thuringiensis.

• 한국식품위생안전성학회지
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• 제35권4호
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• pp.334-340
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• 2020

기존의 L. monocytogenes 증균배지를 개량함으로써 증균배지를 개발하여 L. monocytogenes의 증균 효율을 높이며, DNA 추출에 사용되는 용해버퍼 및 용해조건을 개발함으로써 식육 및 식육가공품에서 L. monocytogenes를 효율적이고 신속하게 검출하고자 하였다. 식품공전에 등재되어 있는 L. monocytogenes 증균배지의 증균 효율을 비교하였으며, Listeria Enrichment Broth (LEB)가 가장 우수한 증균 효율을 보였다. LEB에 탄소원, 질소원, 미네랄 등 다양한 성분을 첨가하여 증균배지를 개발하였으며, 그 결과 LEB에 0.1% pyruvate, 0.1% ferric citrate를 첨가한 개발 증균배지에서 L. monocytogenes가 가장 빠르게 증균되었다. L. monocytogenes의 DNA를 신속하고 효율적으로 추출하기 위해 용해버퍼와 용해조건을 개발하였으며, 그 결과 0.5% 또는 1% N-lauroylsarcosine sodium salt에 0.5 N NaOH와 0.5 M EDTA가 혼합된 용해버퍼를 이용하여 실온에서 30분 간 L. monocytogenes 세포를 용해시키는 것이 DNA의 순도와 수율, 신규성과 경제적 측면에서 가장 우수한 것으로 확인되었다. 결론적으로 본 연구에서 개발된 증균배지 및 DNA 추출법을 활용한다면 식육 및 식육 가공품에서 L. monocytogenes를 보다 신속하게 검출할 수 있을 것이다.

• 약학회지
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• 제56권6호
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• pp.382-389
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• 2012

Effects of citrate-capped silver nanoparticles (AgNPs) on the blood coagulation and platelet aggregation were investigated using whole blood, platelet rich plasma (PRP) and washed platelet obtained from SD male rats. To confirm the stability of AgNPs in the test, size distribution of the nanoparticles was measured in the vehicles including distilled water, serum, and platelet buffers. The average size of AgNPs was 20 nm in the vehicles, which means that the stability was maintained during the whole experimental period. When blood coagulation was monitored by using whole blood impedance aggregometer, coagulation was not observed at the concentration of 1, 10 and 50 ppm. Platelets in plasma or in buffer were not aggregated by AgNPs at the concentration of 1, 2 and 4 ppm, respectively. The test concentration of AgNPs could not be increased because the dark color of the nanoparticles impeded the transmission of light, which is an indicator of aggregation. Although the blood or platelets were pre-activated by collagen, thrombin, or ADP with sub-threshold level, aggregation was not observed at the test concentration. Microscopic observation also supported the result obtained by the aggregometer.

• Journal of Oral Medicine and Pain
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• 제8권1호
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• pp.33-41
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• 1983

The authors observed the ultrastructure of oral leukoplakia simplex of gingiva, buccal mucosa, tongue and alveolar ridge. For the purpose of clearly defining the lesions under investigation in this study, leukoplakias were cinsidered to be any white patches on the oral mucous membranes that could not be removed by rubbing and could not be classified clinically or microscopically as another diagnosable disease. The tissue to be examined were embedded in paraffin for light microscopic study. The tissue to be examined under the electronomicroscope were fixed in 2.5% glutaraldehyde in 0.1M cacodylate buffer and 1% osmic acid in 0.1M cacodylate buffer, dehydrated with guaded alchol, and treated with propylene oxide, and embedded in Epon.Ultrathin sections were obtained by LKB III ultrotome, stained with uranyl acetate/lead citrate, and examined with Corinth 500EM. The results were as follows : 1. Epithelium of leukoplakia consisted of stratum basale, stratum spinosum, stratum granulosum and stratum corneum. 2. There was hyperorthokerotosis or hyperparakeratosis. 3. Granular cells contained a lot number of membrane coating granule showing lamellar structure, clearing ot codensation, and a lot of keratohyaline granule varied in size. 4. An increased concentration of tonofilaments and an increased number of desmosomes were found in the stratum spinosum. 5. Basal lamina generally showed its continuity, but in some locatoins, its interreption and multiplication appeared.

• 한국식품영양과학회지
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• 제28권4호
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• pp.912-916
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• 1999

The purpose of this study was to investigate the effect of saponin in the shoot of Aralia elata on serum lipid level and glucose in streptozotocin(STZ) induced diabetic rats. Sprague Dawley normal male rats weighing 70$\pm$5g were randomly assigned to normal(control group), crude saponin(S group), and shoot of Aralia elata(D group). Experimental diets have been fed for 6 weeks. STZ induced diabetic rats were classified to diabetic control(DC group) and crude saponin(DS group). Diabetic rats were experimentally induced by intravenous injection of STZ(65mg/kg of body weight) dissolved in citrate buffer(pH 4.5). DS group has been i.p. injected with crude saponin solved in phosphate buffer(pH 7.0, 10mg/100g body weight) and DC group fed for 10 days. Body weight decreased significantly in crude saponin group. Feed intakes and feed efficiency ratio were not significantly different among C, S, and D group. The crude saponin group has indicated the lowest values of serum total cholesterol, glucose, and triglyceride. However, the values of serum glucose and triglyceride were not significant. Insulin levels among the crude saponin group, the shoot powder group, and the control group were not significantly different. When STZ induced diabetic rats have i.p. injection of crude saponin, the crude saponin has reduced the serum glucose but it is not been significant.

• 한국미생물·생명공학회지
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• 제8권3호
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• pp.173-180
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• 1980

Streptomyces sp. strain K-17의 포도당 이성화효소의 강력한 분비를 위해서는 inducer로서 D-xylose를 필요로 하고 있다. 그런데 D-xylose를 가하지 않고 1.0% glucose를 가한 배지에서 배양한 이성화효소 역가가 낮은 균체를 모아서 이것을 다시 0.05M인 산 완충액 (PH7.0)에 현탁시켜 0.5 % xylose를 가하여 호기적으로 해주었을 때 효소의 induction pattern을 조사한 결과 효소활성이 10시간까지는 처리 시간에 따라 직선상으로 증가하고 이에 비례해서 D-xylose의 양이 감소했으나 cell mass에 있어서는 거의 변동이 없었다. 이때 효소단백의 합성이 일어나고 있지만, 전 RNA함량에 있어서는 오히려 감소하였다. 이와 같이 질소원을 가하지 않는 non-growth phase에서도 효소단백의 합성이 일어나는 것은 세포내에 축적되어 있는 단백질의 turn-over에 의한다는 것을 starvation 실험에서 알 수 있었다. D-xylose 이외에 D-ribose, L-arabinose, D-glucose, D-mannose, citrate, succinate 및 tartrate는 inducer로서의 효과가 없었다. 효소의 induction시, D-glucose를 가했을 경우catabolite repression 이 일어났으며 succinate 나 citrate 에 의해서도 강하게 효소생성이 억제되었다. 이와 같은 현상은 growth phase에서도 마찬가지 결과를 나타내었다. Induction시, $Ba^{2+}$, $Mg^{2+}$ 및 $Co^{2+}$가 효소생성을 발전시켰으며, C $u^{2+}$, C$d^{2+}$, A $g^{+}$ 및 H $g^{2+}$ 와 같은 중금속이 효소생성을 저해하였고, mitomycin C 몇 penicillin G는 효소생성에 영향을 주지 못하였으나, actinomycin D, streptomycin, chlora-mphenicol 및 tetra cycline등에 의해 강하게 저해되었다. 또 p-CMB 및 uncoupler 인 arsenate와 2.4-DNP에 의해서도 효소생성이 저해되었다.

• 한국동물학회지
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• 제15권3호
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• pp.133-147
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• 1972

고추잠자리(Crocothemis servilia Drury)의 精子完成過程을 究明하기 爲하여, 本 硏究에 着手한 바, 다른 無脊椎動物의 精子完成過程에서 이미 밝혀진 構造들과 比較해 가면서 特殊한 分化相을 觀察한 結果, 첫째 核의 染色質이 漸次 濃縮되기 始作함에 따라서 核의 모양도 球形에서 楕圓形으로, 楕圓形에서 圓錐形으로 變하였으며 둘째로 核이 細胞의 一極端으로 移動하고 核의 尾部가 陷入되며 셋째 中心粒이 核 陷入 部位에 位置하여 여기에서부터 軸　가 形成된다. 넷째는 골지體에서 起因된 尖體顆粒은 核의 先端으로 移動되어 결국 尖體를 形成하게 된다.

• Food Science and Biotechnology
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• 제14권4호
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• pp.543-546
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• 2005

Optimized conditions for protoplast preparation and regeneration from young hyphae of Monascus ruber were established. Heat shock treatment of spores gave rapid and synchronized germination. Spores collected from cultures grown for 7-8 days at $30^{\circ}C$ were germinated until over 70% germ tubes reached to 3-5 spore length. Enzymatic digestion of young hyphae was optimal with 50 mg/mL Glucanex in 0.1 M sodium citrate buffer containing 0.8 M mannitol as an osmotic stabilizer. Regeneration rate was around 10% when 0.8 M sorbitol was used as an osmotic stabilizer in regeneration medium. These conditions will be applied in genetic study of M. ruber that produces citrinin at high level and thus is good model strain for molecular genetic dissection of citrinin biosynthesis.

• 미생물학회지
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• 제18권1호
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• pp.1-6
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• 1980

Five species of food decay fungl, Aspergillus flavus, Asp. uiger, Penicillum sp., Botrytis cinerea, and Rhizopus stolonifer, were examined for their radio sensitivity in several suspension media. Asp. flavus, Asp. niger and Penicillum sp. have almost the same sensitivity toward gamma rays. with D value in the range of 30 to 35 K rad, whereas Botrytis cinerea has a D value of approximately 55K rad and Rhizopus stolonifer, the most re4sistant fungus studied, has a crease in their radioresistnace when compared with spores irradiated in water. Asp. flavus and penicillium sp. spores irradiated in citrate buffer at pH3-7 showed almost no change in their radisensitiity with pH, but Botryis cinerea spores showed a distinct decrease in their radioresistnace at pH 6 and 7. Penicillum sp. spores irradiated in sucrose solutions showed no sinificant change in their radioresistance. Botrytis cinerea spores displayed a higher radioresistance when they were irradiated in sucrose solution than in water.

• Journal of Pharmaceutical Investigation
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• 제24권3호spc1호
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• pp.19-25
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• 1994

The single-pass perfusion technique was employed in order to investigate the effect of water flux from the rat jejunum in the normal experimental conditions. Our results suggested that water flux below ${\pm}0.75%/cm$ of jejunal length was considered normal. Water flux was $-0.131\;{\pm}\;0.311%/cm$ of jejunal length in a citrate buffer and should be corrected in order to determine the permeabilities of the compounds. Perfusion rate up to 0.5 ml/min had no effects on the permeability of ampicillin. Neither the effective permeabilities nor the wall permeabilities of aminopenicillins were influenced by water flux during experiments in rats.