• 제목/요약/키워드: direct count

검색결과 161건 처리시간 0.011초

형광현미경을 이용한 음용 지하수내 배양불능 세균의 관찰 및 정량적 평가 (The Observation and a Quantitative Evaluation of Viable but Non-Culturable Bacteria in Potable Groundwater Using Epifluorescence Microscopy)

  • 김인기;;황경숙
    • 미생물학회지
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    • 제38권3호
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    • pp.180-185
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    • 2002
  • 직접생균수측정법(direct viable count; DVC)과 평판법(p1ate count; PC)을 이용하여 시판되고 있는 먹는샘물, 약수, 도시 인근 지역과 축산농가 밀집지역의 음용 지하수로부터 채수된 시료에 대하여 정략적 평가를 실시하였다. DVC법에 의한 생균수는 전균수(total direct count: TDC)의 약 30~80%, 평판법에 의한 생균수는 DVC의 약1~30%로 나타났다. 이와 같은 결과는 지하수내에 배양 불가능한(viable but non-culturable: VBNC)세균이 높은 비율로 존재함이라고 판단된다. 한편, 통상농도의 영양배지(nutrient broth; NB)와 이를 $10^-2 -2/배로 희석한 영양배지(diluted nutrient broth; DNB)및 R2A배지를 이용하여 계수한 결과, 통상농도의 NB배지에 비해 저영양배지인 DNB와 R2A에서 2~50배 이상 높은 계수치를 나타내었다. 이와 같은 결과로부터 지하수와 같이 빈영양한 환경 내에는 통상농도의 NB배지에서는 중식이 현저히 저해되고 저영양배지에서 중식 가능한 저영양세균이 다수 분포해 있음이라 판단되었다.

Optimal Protocol for Enumeration of Attached Bacteria on Glass Slides

  • Lee, Hyun-Sang;Kwon, Kae-Kyoung;Lee, Jong-Ho;Lee, Hong-Kum
    • Journal of Microbiology
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    • 제37권4호
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    • pp.263-266
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    • 1999
  • In examining bacterial growth on glass surfaces immersed in sea water, we found serious differences between enumeration methods. Therefore, we compared various methods and found sonication and direct count methods were superior to other methods. Since the direct count method was not suitable for long-term investigation, we chose the sonication method and confirmed that sonication periods 8 times for 30 seconds was optimal for the detachment of bacteria from glass surfaces.

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Influence of Pipe Materials and VBNC Cells on Culturable Bacteria in a Chlorinated Drinking Water Model System

  • Lee, Dong-Geun;Park, Seong-Joo;Kim, Sang-Jong
    • Journal of Microbiology and Biotechnology
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    • 제17권9호
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    • pp.1558-1562
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    • 2007
  • To elucidate the influence of pipe materials on the VBNC (viable but nonculturable) state and bacterial numbers in drinking water, biofilm and effluent from stainless steel, galvanized iron, and polyvinyl chloride pipe wafers were analyzed. Although no HPC (heterotrophic plate count) was detected in the chlorinated influent of the model system, a DVC (direct viable count) still existed in the range between 3- and 4-log cells/ml. Significantly high numbers of HPC and DVC were found both in biofilm and in the effluent of the model system. The pipe material, exposure time, and the season were all relevant to the concentrations of VBNC and HPC bacteria detected. These findings indicate the importance of determining the number of VBNC cells and the type of pipe materials to estimate the HPC concentration in water distribution systems and thus the need of determining a DVC in evaluating disinfection efficiency.

Is the Tumor Infiltrating Natural Killer Cell (NK-TILs) Count in Infiltrating Ductal Carcinoma of Breast Prognostically Significant?

  • Rathore, Ankita Singh;Goel, Madhu Mati;Makker, Annu;Kumar, Sandeep;Srivastava, Anand Narain
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3757-3761
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    • 2014
  • Purpose: The aim of this study was to investigate the prognostic significance of the CD56+NK-TIL count in infiltrating ductal carcinoma (IDC) of breast. Material and Methods: Immunohistochemistry (IHC) was performed using antibodies specific for CD56 on formalin-fixed and paraffin-embedded tissue sections of 175 infiltrating ductal carcinomas (IDC) of breast. Distribution of intratumoral and stromal CD56+NK-TILs was assessed semi-quantitatively. Results: A low intratumoral CD56+count showed significant and inverse associations with tumor grade, stage, and lymph node status, whereas it had significant and direct association with response to treatment indicating good prognosis. These patients had better survival (${\chi}^2$=4.80, p<0.05) and 0.52 fold lower death rate (HR=0.52, 95% CI=0.28-0.93) as compared to patients with high CD56+ intratumoral count. The association of survival was insignificant with low CD56 stromal count as compared to high CD56 stromal count (${\chi}^2$=1.60, p>0.05). Conclusion: To conclude, although NK-TIL count appeared as a significant predictor of prognosis, it alone may not be sufficient for predicting the outcome considering the fact that there exists a crosstalk between NK-TILs and the other immune infiltrating TILs.

변형된 DVC법을 이용한 난배양성 토양세균의 검출 및 정량적 평가 (The Detection and a Quantitative Evaluation of Viable but Non-Culturable Soil Bacteria Using a Modified Direct Viable Count Method)

  • 황경숙;양희찬;염곡효
    • 미생물학회지
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    • 제39권3호
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    • pp.181-186
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    • 2003
  • 형광현미경을 이용한 기존의 직접생균수측정(DVC)법을 변형하여 산림토양의 각 층위에 분포하는 난배양성 토양세균의 정량적 평가를 시도하였다. 기존의 방법에서 사용된 DNA합성저해제(nalidixic acid; 100${\mu}g$/ml, pipemidic acid; 50 ${\mu}g$/ml, piromidic acid; 50 ${\mu}g$/ml)보다 5배 높은 농도를 사용한 결과 토양세균 군집의 세포분열이 배양24시간까지 분히 억제되어 기존의 DVC법보다 10배 이상 높은 계수치를 얻었다. 토양시료를 제균수로 원심 세척한 경우 DVC는 전균수(TDC)의 약 I% 미만을 나타내어 첨가된 기질의 이용능을 정확히 판정할 수 있었다. 형광현미경을 이용하여 DVC법에 의해 검출된 생균수는 전균수의 18-44%를 나타내었고, 평판법(PC)에 의해 계수된 생균수는 전균수의 1% 미만을 나타내어 DVC법이 평판법에 비해 100-2000배 이상 높은 계수치를 나타내었다. 이는 평판법으로는 배양할 수 없는 난배양성(VBNC)세균이 토양 내에 다수 존재해 있음으로 판단되었고, DVC법에 의해 난배양성 토양세균을 정량적으로 검출할 수 있는 가능성이 확인되었다. 영양기질로써 통상농도의 NB배지와 NB를 $10^{-2}$로 희석한 DNB배지를 사용하여 DVC법과 평판법에 의한 계수 결과를 비교한 결과 모든 시료에서 DNB배지에서의 생균수는 NB배지보다 5~10배 이상 높은 값을 나타내어 산림토양의 각 층위에 저영양세균(oligotrophic bacteria)이 다수 분포해 있음으로 추정되었다.

호수 생태계에서 살아있는 세균을 측정하기 위한 qDVC 방법의 적용 (Application of qDVC Method for Measuring Viable Cells in Lakes)

  • 김미리;서은영;최승익;안태석
    • 미생물학회지
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    • 제42권3호
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    • pp.205-209
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    • 2006
  • 호소수내의 '살아있는 세균'을 측정하기 위하여 quantitative direct viable count (qDVC) 방법을 적용하였다. qDVC방법에 적용되는 최적 glycine 농도는 2%였으며, '살아있는 세균'을 계수하는데 있어서 평판계수법, CTC법 보다는 qDVC 방법이 보다 효과적이라는 것을 확인하였다. qDVC방법으로 '살아있는 세균'을 측정한 결과 다른 두 방법보다 $2.4{\sim}6.0$배 높은 값이었다. 또한 qDVC방법은 '살아있는 세균'을 죽은 세포 또는 휴면세포와 쉽게 구별할 수 있었다.

The Ongoing Effect of Transcranial Direct Current Stimulation on both the Hemispheres: Single Case fMRI Study

  • Kwon, Jung-Won;Son, Sung-Min;Kim, Chung-Sun;Cho, In-Sul
    • The Journal of Korean Physical Therapy
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    • 제23권6호
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    • pp.49-53
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    • 2011
  • Purpose: The purpose of this study is to investigate whether dual-hemisphere transcranial direct current stimulation (tDCS) could induce more cortical activity, compared to single-hemisphere, using functional MRI (fMRI). Methods: One right-handed healthy subject was recruited. Three phases of dual-hemisphere tDCS (i.e. anodal tDCS over the left-dominant primary sensoriomotor cortex (SM1) and cathodal tDCS over the right-non dominant SM(1) were consecutively delivered on to a subject, during fMRI scanning. The voxel count and the intensity index in the averaged cortical map were analyzed among the three tDCS phases. Results: Our result showed that cortical activation was observed on all the three phases of the dual-hemisphere tDCS. Voxel count and intensity index were as following; 912 and 4.07 in the first phase, 1102 and 3.90 in the second phase, 1031 and 3.80 in the third phase. Conclusion: This study demonstrated that application of the dual-hemisphere tDCS could induce cortical activity and maintain to recruit cortical neurons. Our findings suggested that application of dual-hemisphere tDCS could produce efficiency of the ongoing tDCS effect to facilitate cortical excitability.

총백혈구수(總白血球數), 호산구수(好酸球數) 및 기타 백혈구수(白血球數)의 직접계산(直接計算)을 위한 개량희석액(改良稀釋液)에 관한 연구(硏究) (Study on Improved Diluting Fluids for Direct Counts of Total Leukocyte, Eosinophil and Other Leukocytes)

  • 이방환
    • 대한수의학회지
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    • 제16권2호
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    • pp.105-114
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    • 1976
  • The study was conducted for an attempt to improve the diluting fluid for total leukocyte count, and to prepare a multipurpose diluting fluid for concurrent direct counts of total leukocytes, eosinophils and the other leukocytes. Through the experiment, two better fluids for total leukocyte count of blood of human, bovine, swine, canine and rabbit were selected, and which conserved cell morphology of leukocytes better than $T{\ddot{u}}rk$-solution. Each formula of two fluids were given as under R I and R II. Formula of multipurpose diluting fluid selected in the experiment was given as under III. With this fluid, direct counts of total leukocytes, eosinophils and probably basophils of blood of human, bovine and swine were practicable concurrently in the same counting chamber of a hemocytometer. In this fluid, eosinophils were stained red in the part of eosinophilic granules and blue in other part of cell, and basophils were stained dark blue like as a lump of black granules, staining three other leukocytes faint blue. Eosinophils of canine blood were not so enough red those in other animal and human and eosinophils of rabbit blood were not distinguishable from pseudoeosinophils in this fluid.

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황색포도상구균의 TEMPO STA와 표준 평판 배지를 이용한 정량분석법 비교 (Comparison of an Automated Technique TEMPO with Direct Plate Count Method for the Enumeration of Staphylococcus aureus)

  • 조용선;이다연;이주영;왕해진;신동빈
    • 한국식품위생안전성학회지
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    • 제28권3호
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    • pp.252-257
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    • 2013
  • 표준 평판배지 정량검출법과 TEMPO STA를 이용한 황색포도상구균 정량 분석에 대한 상관성과 유의성을 평가하기 위해 복합조리식품에 황색포도상구균을 인위적으로 접종하여 결과값을 통계 처리하여 유의성을 조사한 결과 두 실험방법간에는 유의적 차이가 없었다(p < 0.05). 상관계수($r^2$)는 0.9672로 두 실험간에는 높은 연관성을 보였다. TEMPO STA를 466개의 시료에 적용한 결과 454개(97.4%)의 시료는 문제가 없었으나 이중 12개의 시료에서는 error가 발생하였다. 그러나 TEMPO법은 실험 단계 간편하고 사용이 쉬우며 신속한 결과를 얻을 수 있으며 자동화된 장비로 실험 과정에 의한 오류를 최소화 할 수 있는 장점이 있으며 표준시험법인 표준 평판 배지법과도 유의적인 차이가 없어 정확한 정량검출이 가능할 것으로 생각된다. 최근 식품의 안전성확보를 위해 검사 품목이 다양해지며 수도 증가하는 추세이기 때문에 황색포도상구균의 정량 검사가 정확하고 신속해야 할 필요가 있으므로 TEMPO STA법의 필요성은 앞으로 크게 늘어날 것으로 보인다.

Mitigation of Voltage Sag and Swell Using Direct Converters with Minimum Switch Count

  • Abuthahir, Abdul Rahman Syed;Periasamy, Somasundaram;Arumugam, Janakiraman Panapakkam
    • Journal of Power Electronics
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    • 제14권6호
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    • pp.1314-1321
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    • 2014
  • A new simplified topology for a dynamic voltage restorer (DVR) based on direct converter with a reduced number of switches is presented. The direct converter is fabricated using only three bi-directional controlled switches. The direct converter is connected between the grid and center-tapped series transformer. The center-tapped series transformer is used to inject the compensating voltage synthesized by the direct converter. The DVR can properly compensate for long-duration, balanced, and unbalanced voltage sag and swell by taking power from the grid. The switches are driven by ordinary pulse width modulation signals. Simulation and hardware results validate the idea that the proposed topology can mitigate sag of 50% and swell of unlimited quantity.