• 미생물학회지
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• 제38권1호
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• pp.50-53
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• 2002

백강균(Beauveria bassiana DGUM 34001)은 $24^{\circ}C$의 온도와pH 7.0의 초기 pH에서 최적의 균사체 생육을나타내었다. 사용한 복합배지 중 mushroom complex배지(MCM)에서 가장 우수한 균사생육을 나타내었다. Czapek-Dox 한천배지를 최소배지로 각각 탄소원, 질소원 및 인산원의 영향을 조사한 결과, glucose, soytone 및 sodium phosphate ($NaH_2$$PO_4$)에서 가장 우수한 균사 생육을 보여주었다. MCM액체배지에서 균사 배양 후 세포외 효소 활성을 측정한 결과,$\alpha$-amylase, lipase, chitinase, CMCase및 pretense의 비효소활성은 각각 297.0, 0.058, 0.33, 0.21 및 22.8 units/mg protein이었다. Casein과 soluble chitosan을 첨가할 경우 세포외 분비 pretense와 chitinase의 효소 활성 이 증가되었다.

• 대한미생물학회지
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• 제22권4호
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• pp.445-451
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• 1987

Coagglutination method is widely used for the diagnosis of Salmonella infection. This test, however, has a disadvantage of false positive reaction due to the coagglutination of staphylococci with non-specific immune complexes or anti-staphylococci antibody in serum. Salmonell O antigen was detected by enzyme immunoassay with protein A-bearing Staphylococcus aureus as in the solid phase. Horse radish peroxidase was labeled to IgG specific against Salmonella O antigen. This enzyme immunoassay was much more sensitive than conventional coagglutination method without false poitive agglutination. To improve the sensitivity for detection of Salmonella O antigen in samples, we tried to determine the optimal concentration of normal IgG that inhibits non-specific binding of horse radish peroxidase labeled IgG to staphylococci, and to establish the optimal condition of reaction between antigen-antibody complex and staphylococci. Non-specific binding of horse radish peroxidase labeled specific IgG to staphylococci was almost blocked when the enzyme labeled IgG was 500-fold diluted with phosphate buffered saline containing 2mg/ml of normal IgG. When staphylococci coated with antibody to Salmonella O antigen were mixed with antigen-antibody complex and then incubated for 1 hour at room temperature, the minimal detectable concentration of Salmonella O antigen was 1ng/ml. The sensitivity of enzyme immunoassay was 100-fold greater than a conventional coagglutination method. This enzyme immunoassay could be expected as an improved method for detection of other infectious agents.

• Mass Spectrometry Letters
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• 제6권3호
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• pp.71-74
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• 2015

Low temperature plasma (LTP) ionization mass spectrometry (MS) is one of the widely used ambient analysis methods which allows soft-ionization and rapid analysis of samples in ambient condition with minimal or no sample preparation. One of the major advantages of LTP MS is selective analysis of low-molecular weight, volatile and low- to medium-polarity analytes in a sample. On the contrary, the selectivity for particular class of compound also implies its limitation in general analysis. One of the critical factors limiting LTP ionization efficiency is poor desorption of analytes with low volatility. In this study, a home-built LTP ionization source with Peltier heating sample stage was constructed to enhance desorption and ionization efficiencies of analytes in a sample and its performance was evaluated using standard mixture containing fatty acid ethyl esters (FAEEs). It was also used to reproduce the previous bacterial identification experiment using pattern-recognition for FAEEs. Our result indicates, however, that the bacterial differentiation from FAEE pattern recognition using LTP ionization MS still has many limitations.

• 대한두경부종양학회지
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• 제13권2호
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• pp.241-246
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• 1997

It has become evident in recent years that parathyroid adenoma and well differentiated thyroid cancer occur together more than would be expected by chance alone. However, the association between them is not well understood. We have experienced 4 cases of coexistent parathyroid adenoma and well-differentiated thyroid cancer during the past 16 years. None of them had a familial incidence or a history of radiation exposure. Three cases showed symptomatic hypercalcemia(including renal stones, bone pain, joint pain) and in two of them(patient 1 and patient 2), thyroid abnormalities were detected preoperatively by neck ultrasonography or neck CT for evaluation of parathyroid lesions. However, in patient 3, a parathyoid humor was identified and removed incidentally during the course of thyroidectomy. In 3 cases, surgeries for thyroid carcinoma and parathyroid adenoma were performed during the same exploration of the neck, but in patient 4, thyroidectomy preceded parathyroidectomy; The interval between thyroidectomy and subsequent parathyroidectomy was 11 yeras. The thyroid tumors in 3 cases were papillary carcinoma, the sizes of which ranged from 1.0 cm to 1.5 cm in greatest diameter. The remaining case(patient 4) was minimal invasive follicular carcinoma. Total or near-total thyroidectomy with various types of cervical lymphnode dissection and bilateral neck exploration for the parathyroid lesion was performed in 3 cases with papillary carcinoma. Ipsilateral lobectomy and contralateral partial thyroidectomy with consequent unilateral neck exploration for the parathyroid tumor was performed in the case of follicular cancer. In our experience, parathyroid adenoma and well-differentiated thyroid carcinomas can be coexistent and we felt that the attention to the hypercalcemic patients would be needed for detection of this rare condition.

• 한국정보통신학회논문지
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• 제16권9호
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• pp.2021-2030
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• 2012

조기심실수축(PVC)은 가장 보편적인 부정맥으로 심실세동, 심실빈맥 등과 같은 위험한 상황을 유발할 수 있는 가능성을 가지고 있기 때문에 이의 조기 검출은 매우 중요하다. 특히 일반인들의 건강상태를 지속적으로 모니터링 해야 하는 헬스케어 시스템에서는 이를 위한 심전도 신호의 실시간 처리가 필요하다. 즉, 최소한의 연산량으로 정확한 R파를 검출하고, 대상 환자의 특징을 파악하여 PVC를 분류할 수 있는 적합한 알고리즘의 설계가 필요하다. 따라서 본 연구에서는 PVC 실시간 분류를 위한 환자 적응형 패턴 매칭 기법을 제안한다. 이를 위해 전 처리 과정과 적응 가변형 문턱 값과 윈도우를 통해 R파를 검출하였으며, 검출 대상에 따른 정상신호 군을 선별하고 이를 벗어나는 신호를 이상신호로 분류하기 위해 해쉬 함수를 통한 패턴 매칭 기법을 적용하였다. 제안한 알고리즘의 R파 검출 및 정상신호 분류 성능을 평가하기 위해서 MIT-BIH 부정맥 데이터베이스를 사용하였다. 성능평가 결과, R파는 평균 99.33%, 이상신호 분류에 대한 에러율은 0.32%로 나타났다.

• 대한의용생체공학회:의공학회지
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• 제23권4호
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• pp.295-300
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• 2002

국부적 저산소증(localized hypoxia)은 산소공급의 저하로 인하여 조직세포를 파괴하고 관강압력에 대한 동맥류 벽의 저항을 현저하게 감소시킨다고 보고되고 있다. 본 연구에서는 동맥류 파열의 원인이 되는 저산소증의 기전을 이해하기 위하여 혈전의 두께에 따라 세 가지의 축대칭 동맥류 모델을 구성하여 동맥류 내 혈전을 통한 정상 층류유동 (steady laminar flow)에서의 산소전달현상(O$_2$transport phenomenon)을 유체-고체 열전달 현상과의 유사성을 이용하고 Fick의 법칙을 적용하여 해석하였다. 전산해석을 통해서 혈전이 형성된 혈관에서 산소농도는 혈관 벽에서 가장 낮게 나타났으며 혈전의 크기가 증가할수록 저산소농도(low $O_2$concentration) 영역이 혈관 벽 가까이 넓게 분포되어 저산소증의 가능성이 증가됨을 알 수 있었다 본 연구를 통해서 동맥류 내의 혈전은 구조와 크기에 따라 산소의 흐름에 주요한 영향을 미침을 확인할 수 있었다.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.590-596
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• 2016

Biopsy is a typical needle type intervention procedure performed under radiographic image equipment such as computed tomography (CT) and cone-beam CT. This minimal invasive procedure is a simple and effective way for identifying cancerous condition of a suspicious tissue but radiation exposure for the patients and interventional radiologists is a critical problem. In order to overcome such trouble and improve accuracy in targeting of the needle, there have been various attempts using robot technology. Those devices and systems, however, are not for full procedure automation in biopsy without consideration for tissue sampling task. A robotic end-effector of a master-slave tele-operated needle type intervention robot system has been proposed to perform entire biopsy procedure by the authors. However, motorized sampling adopted in the device has different cutting speed from that of biopsy guns used in the conventional way. This paper presents the design of a novel robotic mechanism and protocol for the automation of biopsy procedure using spring-triggered biopsy gun mechanism. An experimental prototype has been successfully fabricated and shown its feasibility of the automated biopsy sequence.

• 약학회지
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• 제40권1호
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• pp.102-111
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• 1996

LB10522 is a new parenteral broad spectrum cephalosporin with a catechol moiety at C-7 position of beta-lactam ring. This compound can utilize tonB-dependent iron transp ort system in addition to porin proteins to enter bacterial periplasmic space and access to penicillin-binding proteins (PBPs) which are the lethal targets of ${\beta}$-lactam antibiotics. The chelating activity of LB10522 to metal iron was measured by spectrophotometrically scanning the absorbance from 200 to 900nm. When $FeCl_3$ was added, optical density was increased between 450 and 800nm. LB10522 was more active against gram-negative strains in iron-depleted media than in iron-replete media. This is due to the increased expression of iron transport channels in iron-depleted condition. LB10522 showed a similar activity against E. coli DC2 (permeability mutant) and E. coli DCO (wild type strain) in both iron-depleted and iron-replete media, indicating a minimal permeaility barrier for LB10522 uptake. LB10522 had high affinities to PBP 3 and PBP 1A, 1B of E. coli. By blocking these proteins, LB10522 caused inhibition of cell division and the eventual death of cells. This result was correlated well with the morphological changes in E. coli exposed to LB10522. Although the in vitro MIC of LB10522 against P. aeruginosa 1912E mutant (tonB) was 8-times higher than that of the P. aeruginosa 1912E parent strain, LB10522 showed a similar in vivo protection efficacy against both strains in the mouse systemic infection model. This result suggested that tonB mutant, which requires a high level of iron for normal growth, might have a difficulty in surviving in their host with an iron-limited environment.

• 한국식품저장유통학회지
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• 제9권2호
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• pp.126-130
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• 2002

저장실험용 과채류인 오이와 단감을 서부 경남 진주시 지역의 재배농가에서 저장실험 시작당일 직접 구입하여 사용하였다. 구입즉시, 과채류를 습도가 70%(저장온도 $25^{\circ}C$), 80%(저장온도 1$0^{\circ}C$) 및 90%(저장온도: 단감 5$^{\circ}C$, 오이 1$0^{\circ}C$)의 저장조건에 보관하면서 처리기간별로 채취하여 품질변화를 측정하였다. 실험결과, 5$^{\circ}C$ 또는 1$0^{\circ}C$에서 습도 90%조건하에 오이와 단감을 저장할 경우, 중량손실율이 최소가 되었으며, ascorbic acid의 감소율을 크게 줄일 수 있었고, 오염 미생물의 생육이 억제되어 과일의 변패현상을 방지할 수 있었으며, 저장중 표면색도의 변화를 최소화할 수 있어 소비자의 기호도를 만족시킬 수 있었다. 부패율 또한, 저온에서 90% 저장습도에 저장하였을 때, 변패 곰팡이의 오염도 및 오이와 단감의 조직연화현상이 크게 억제되었다. 이상의 연구결과를 토대로 하여 볼 때, 오이와 단감을 저장할 때, 모든 처리시험구에서 저장습도 90%를 유지하는 조건에서 저온 저장하는 경우, 선도유지기간을 최대한 연장할 수 있음을 확인할 수 있었다.

• 한국임상수의학회지
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• 제25권5호
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• pp.346-354
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• 2008

The combined effects of EDTA-Tris and eighteen antimicrobial agents have been evaluated in eight clinically isolated methicillin-resistant bacteria (Staphylococcus aureus, Escherichia coli, Streptococcus uberis and Streptococcus agalactiae) from bovine mastitis. The antimicrobial activity was evaluated by measuring the minimal bactericidal concentration (MBC) for the antibiotics alone or in combination with EDTA-Tris in Mueller-Hilton broth and milk. Combined use of EDTA-Tris and antibiotics potentiated or antagonized activity of antibiotics against mastitic pathogens. Milk increased the antibiotic potency of erythromycin and spiramycin on S. aureus. Culture in milk changed patterns of EDTA-Tris combinational effects compared with that in standard Mueller-Hilton broth. Combined with EDTA-Tris in milk, synergic effects were observed in colistin, dihydrostreptomycin, kanamycin, erythromycin, gentamycin, oxytetracycline, streptomycin to E. coli, Str. uberis, and Str. agalactiae. However, significant antagonistic effects of milk on antibiotic susceptibility in combination with EDTA-Tris were noted in neomycin, streptomycin, penicillin, roxithromycin, and amoxicillin. This study indicates that combination therapy of EDTA-Tris with antibiotics in bovine mastitis should be used with caution because of the possible antagonistic effects of antibiotic combination with EDTA-Tris on mastitic pathogens. In addition, antibiotic susceptibility test in combination with EDTA-Tris in milk culture condition can be benefit in search of effective treatment regimen for some antibiotic-resistant bacteria of mastitis.