Staphylococcus aureus is gram positive, facultatively anaerobic, non-sporulative coccus, and positive for coagulase and DNase. The food oisoning outbrealc of Staphylococcus aureus increases in the world, and third occurnn happened in our country. Of 105 isolates (25.4%) obtained 413 fecal samples of food-poisoning suspicious patients. In those cases, the enterotoxins were detected firom a total of 45 isolates (42.9%), 9 isolates(20.0%) were A type, 33 isolates (73.3%) we H types, 2 isolates (4.4%) were G type and 1 isolate was a I type enterotoxin. Among the isolates possessing staphylococcal enterotoxins, 29 isolates had H type only(64.4%), 5 isolates had A type only and 4 isolates had both A and H type. 'Iieo isolates had G type only and 1 isolate had I type only. In the antibiotic susceptibility, 48 isolates (46%) had at least one antibiotic resistance among 105 isolates, 34 isolates (70.8%) were resistant to penicillin, 1 isolate (2.1%) to ampicillin, 3 isolates (6.3%) to erythromycin and kanamycin. Seven were resistant to more than two antibiotics and especially 1 isolate was resistant to penicillin-ampicillin-nitrofurantoin.

To investigate the effects of bacterial endotoxin on lipids and cytokines, and to explain the relationships between their changes, we carried out this study using experimentally Escherichia coli (E. coli) endotoxin-induced septicemic rabbits. The triglyceride and cholesterol concentrations in endotoxin groups were generally high (p$lt;0.01 or 0.05) at all sampling time points (from 3hr to 24 hr), while phospholipid concentrations in endotoxin groups elevated in dose-dependent fashion at 3hr and 6hr after endotoxin injection compared to control group (p$lt;0.05). There were significant negative correlations between lipids changes and cytokines (TNF-α and IL-1β) each other (p$lt;0.05), and endotoxic rabbits having higher triglyceride of cholesterol levels shown relatively better conditions compared with others. As a result, the alterations in the lipid compositions caused by endotoxin may imply an active exhibition of the host defense mechanism rather than the disturbances of lipid metabolism.

diol을 기반으로 하는 Sol-Gel 방법으로 PZT (53/47) 1M sol 용액을 만들어 회전 코팅법으로 Pt/Ti/SiO2/Si 기판위에 코팅하였고 한번 코팅으로 최대 0.9μm 의 PZT막을 얻었다. PZT는 비강유전성 pyrochlore상을 거쳐 강유전성 perovskite상으로 전이하며 따라서 PZT perovskite seed가 상전이에 미치는 영향을 규명하고자 하였다. 0.2μm 이하의 크기를 갖는 1wt% PZT분말을 propanol용액에 분산시켜 PZT sol 용액에 도입하여 seeded PZT 막을 제조하였다. Seeded PZT막을 열처리한 결과 perovskite상의 생성이 촉진되어 상전이 온도가 50˚C정도 낮아졌다.

The purpose of this experiment was to determine the effects of thiol compounds, -mercaptoethanol(-ME) and cystearrone with buffalo rat liver cell(BRLC) co-culture on the development and intracellular glutathione(GSH) concentrations of bovine embryos produced by in vitro inaturation(IVM) and in vitro fertilization(IVF). Bovine IVM /IVF embryos developed to 2~8 cell stage were co-cultured with BRLC in GRlaa with or without thiol compounds. The developmental rate beyond morulae stage in CRlaa containing 0, 10,25 and 50M -ME with BRLG were 63.0, 74.0, 72.3 and 77.1%, respectively. And the developmental rate with 0, 25, 50 and 75M cystearnine with BRLC were 69.6, 77.6, 81.0 and 76.8%, respectively. The developmental rate beyond morulae stage of GRlaa containing thiol compound with BRLG group was higher than that of control group. The intracellular GSH concentrations of blastocysts cultured for 5 days in GRlaa containing 0 and 50M -ME or cysteamine with BRLG were 81.2 and 86.4, 83.2 and 84.2pM, respectively. The intracellular GSH concentrations of blastocysts in GRlaa containing thiol compounds with BRLG was slightly higher than that of control group The cell numbers of blastocysts were not difference in all experimental groups. These results indicate that thiol compounds with BRLG co-culture was increased the percentage of developed into morulae and blastocysts, and intracellular GSII concentrations of blastocysts embryos.

An experimental study was conducted to investigate the effects of chlorine dioxide and ozone on reduction of THM(trihalomethane) formation. Precursor concentration, chlorine concentration, reaction time, pH, and temperature were governing compornents of THM formation. When other conditions are constant, THM formation increased linearly with precursor concentration increased. THM formation increased when pH increased from 5 to 9. In combined treatment with chlorine and chlorine dioxide, chlorine treatment after chlorine dioxide treatment made less THM than any other case does. Ozonation reduced THMFP(THM formation potential) of THM precursor. THMFP decreased exponentially with reaction time increased. Also biodegradability of humic acid was enhanced by ozonation.

여러 연구자들의 연구결과를 토대로 하여 침채류의 염장 발효과정중 나타나는 여러가지 화학적 성분과 조직감의 변화를 살펴본 결과, 식물조직의 변화는 펙틴질의 성질에 크게 영향을 받고 있었으며, 이러한 조직의 변화에 관여하는 요인들은 소금의 종류 및 농도, 절임시간, 온도, 예열처리, 염혼합물, 효소, 젓갈, 마늘첨가량 등이 복합적으로 작용하고 있었다.

Quantizing and extracting visual features of mushroom(Lentinus edodes L.) are crucial to the sorting and grading automation, the growth state measurement, and the dried performance indexing. A computer image processing system was utilized for the extraction and measurement of visual features of front and back sides of the mushroom. The image processing system is composed of the IBM PC compatible 386DK, ITEX PCVISION Plus frame grabber, B/W CCD camera, VGA color graphic monitor, and image output RGB monitor. In this paper, an automatic thresholding algorithm was developed to yield the segmented binary image representing skin states of the front and back sides. An eight directional Freeman's chain coding was modified to solve the edge disconnectivity by gradually expanding the mask size of 3×3 to 9×9. A real scaled geometric quantity of the object was directly extracted from the 8-directional chain element. The external shape of the mushroom was analyzed and converted to the quantitative feature patterns. Efficient algorithms for the extraction of the selected feature patterns and the recognition of the front and back side were developed. The developed algorithms were coded in a menu driven way using MSC language Ver.6.0, PC VISION PLUS library fuctions, and VGA graphic functions.

In this study, we investigated the in vitro anti-biofilm activities of plant extracts of chives (Allium tuberosum), garlic (Allium sativum), and radish (Raphanus sativus L.) against environment harmful bacteria (gram-positive Staphylococcus aureus and, gram-negative Salmonella typhimurium and Escherichia coli O157:H7). In the paper disc assay, garlic extracts exhibited the highest anti-biofilm activity. The Minimal Inhibitory Concentration (MIC) of all plant extracts was generally higher for gram-negative bacteria than it was for gram-positive bacteria. Gram-negative bacteria were more resistant to plant extracts. The tetrazolium dye (XTT) assay revealed that, each plant extract exhibited a different anti-biofilm activity at the MIC value depending on the pathogen involved. Among the plant extracts tested, garlic extracts (fresh juice and powder) effectively reduced the metabolic activity of the cells of food-poisoning bacteria in biofilms. These anti-biofilm activities were consistent with the results obtained through light microscopic observation. Though the garlic extract reduced biofilm formation for all pathogens tested, to elucidate whether this reduction was due to antimicrobial effects or anti-biofilm effects, we counted the colony forming units of pathogens in the presence of the garlic extract and a control antimicrobial drug. The garlic extract inhibited the E. coli O157:H7 biofilm effectively compared to the control antimicrobial drug ciprofloxacin; however, it did not inhibit S. aureus biofilm significantly compared to ciprofloxacin. In conclusion, garlic extracts could be used as natural food preservatives to prevent the growth of foodborne pathogens and elongater the shelf life of processed foods.

4차 산업혁명 사회에서의 PNT(Position, Navigation, and Timing) 정보의 중요성은 과거와는 또 다른 의미를 가진다. 자율 주행차, 자율 운항선박, 스마트그리드 그리고 국가 주요 기간시설에서는 PNT 정보의 고정확성 이외에도 지속가능하고, 신뢰할만한 서비스를 요구하 고 있다. PNT 정보를 제공하는 가장 대표적인 시스템인 위성항법시스템은 지구 대기 밖 위성으로부터 신호를 수신하므로 수신 신호전력이 낮고, 민간신호의 경우 신호구조가 공개되어 있다. 따라서 비의도적 또는 의도적인 간섭이나 해킹에 취약하다. 사용자 관점에서 적은 비용으 로 높은 성능의 PNT 정보를 쉽게 획득할 수 있는 위성항법시스템은 해킹의 취약성 때문에 이에 대한 보완이 요구된다. 이에 따라 응용분야 별로 다양한 연구가 진행되고 있으며, 본 논문에서는 기회신호 측면에서 현재 구축, 운영 중인 해상항법 및 통신 인프라를 활용한 R-Mode(Ranging Mode) 기술에 대해 다룬다. 이를 위하여 현재 전국망의 중파 비컨 기반 보강정보를서비스하고 있는 NDGNSS(Nationwide Differential Global Navigation Satellite System) 인프라에 대해 알아보고, 시뮬레이션을 통하여 국내 해상분야에서의 백업 PNT 기술로서의 가능성을 확인한다.