• 제목/요약/키워드: Phase contrast microscopy

검색결과 138건 처리시간 0.025초

식초음료의 Candida albicans에 대한 성장억제 기전에 관한 연구 (A study of growth inhibition mechanism of vinegar drink on Candida albicans)

  • 김애옥;최충호;홍석진
    • 한국융합학회논문지
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    • 제9권12호
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    • pp.137-143
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    • 2018
  • 이 연구는 Candida albicans에 대한 과일식초음료의 항진균 억제 기전에 관하여 알아보고자 하였다. 식초음료가 C. albicans의 성장, 유전자 억제와 형태 변화에 미치는 영향을 평가하기 위하여 위상차현미경, Real-Time PCR 등을 시행하여 평가하였다. C. albicans의 생장력 검사 결과 식초 음료 첨가시 모두 성장이 억제되는 결과를 보였다. 또한 ALS3, ECE1, HWP1, Sap5의 발현 수준을 측정한 결과 식초 음료를 첨가한 경우 유전자 발현이 모두 감소되었다. 위상차 현미경으로 검사한 결과, 식초 음료를 첨가한 그룹은 C. albicans의 현저한 양적 감소, 형태학적 변화 및 억제를 보였다. 이 연구 결과는 식초 음료에 항진균 활성을 나타내는 성분이 있으며 구강 건강을 위한 항진균제 개발의 기초 자료로 사용될 수 있음을 시사한다.

일부 지적장애 학생을 위한 구강건강관리 프로그램에 관한 사례연구 (A Case Study of Oral Healthcare Program for Some Students with Intellectual Disabilities)

  • 손정희;최원익;임도선;최은미
    • 한국콘텐츠학회논문지
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    • 제19권2호
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    • pp.204-209
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    • 2019
  • 이 연구는 충청북도에 위치한 C 특수학교 고등부에 재학 중인 지적장애 학생을 대상으로 구강건강관리 프로그램을 개발하여 적용한 운영효과를 확인하기 위해 적용하였다. 구강건강관리 프로그램은 1주 간격으로 총3번 진행하였으며, 사전에 수집한 정보를 기반으로 교육자료를 개발하였다. 매 회차마다 구강보건교육과 자가 및 전문가치면세균막 관리를 시행하였으며, 프로그램의 효과를 알아보기 위하여 구강환경관리능력지수, 치아우식발생 위험도, 위상차현미경을 관찰 및 검사하였다. 구강건강관리 프로그램 전 후 PHP index는 $3.21{\pm}0.69$에서 $2.42{\pm}0.80$로 감소하였고, 치아우식발생 위험도는 13.78이 감소하였지만, 통계적으로 유의한 차이를 보이지 않았다(p>0.05). 위상차현미경을 관찰한 결과 1회차에 비하여 3회차에서는 구균의 수가 감소하였고, 간균이 거의 보이지 않았다. 또한 구강미생물의 운동성도 현저히 감소함을 확인할 수 있었다. 반복 교육과 동기유발을 포함한 구강건강증진 프로그램은 지적장애 학생들의 구강환경관리 능력을 개선시키고 치아우식 발생 가능성을 낮출 수 있다.

방사광 위상차 현미경을 이용한 생체조직의 미세구조 영상 (Synchrotron Radiation Imaging of Tissues Using Phase Contrast Technique)

  • 강보선;이동열;김기홍
    • 한국방사선학회논문지
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    • 제2권2호
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    • pp.23-30
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    • 2008
  • 방사광 X-선 현미경은 임상실험에 유용한 도구로 높은 배율과 고 해상도로 동물 장기조직 시료의 세부 구조를 관찰할 수 있다. X-선 영상은 위상 대조도 메커니즘으로 설명할 수 있다. 우리는 쥐의 꼬리, 신경 및 허파의 in-vivo 및 in-vitro위상 대조도 영상을 8 KeV mono 빔으로부터 10배 현미경대물렌즈와 CCD 카메라를 이용하여 얻었다. 기존의 흡수 X-선 영상 보다 SR 영상이 세밀한 구조의 높은 분해능 영상을 볼 수 있었다. SR 영상은 생물학, 재료 및 임상 연구에 무한한 가능성을 가지고 있다.

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Bufalin Induces Mitochondrial Pathway-Mediated Apoptosis in Lung Adenocarcinoma Cells

  • Ding, Da-Wei;Zhang, Yong-Hong;Huang, Xin-En;An, Qing;Zhang, Xun
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권23호
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    • pp.10495-10500
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    • 2015
  • Background: To evaluate the effects of bufalin in A549 human lung adenocarcinoma epithelial cells in vitro and assess the underlying mechanisms. Materials and Methods: Human A549 non-small cell lung cancer (NSCLC) cells were treated with various concentrations of bufalin. Cell proliferation was measured by CCK-8 assay, apoptotic cell percentage was calculated by flow cytometry and morphological change was observed by inverted phase contrast microscopy/transmission electron microscopy. In addition, the membrane potential of mitochondria was detected by JC-1 fluorescence microscopy assay, and the related protein expression of cytochrome C and caspase-3 was analyzed by Western blotting. Results: Bufalin could inhibit the proliferation of A549 cells via induction of apoptosis, with the evidence of characteristic morphological changes in the nucleus and mitochondria. Furthermore, bufalin decreased the mitochondrial membrane potential with up-regulation of cytochrome C in the cytosol, and activation of caspase-3. Conclusions: Bufalin inhibits the proliferation of A549 cells and triggers mitochondria-dependent apoptosis, pointing to therapeutic application for NSCLC.

석면섬유 자동계수를 위한 고효율 현미경법의 영상처리 알고리즘 개선 (Improvement of Image Processing Algorithm of High-Throughput Microscopy for Automated Counting of Asbestos Fibers)

  • 조명옥;윤성희;한화택;김중경
    • 한국가시화정보학회지
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    • 제13권3호
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    • pp.15-19
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    • 2015
  • We developed a high-throughput microscopy (HTM) method which enabled us to replace a conventional phase contrast microscopy (PCM) method that has been used as a standard analytical method for airborne asbestos. We could obtain the concentration of airborne asbestos fibers under detection limit by automated image processing and analysis using HTM method. Here we propose an improved image processing algorithm with variable parameters to enhance the accuracy of the HTM analysis. Since the variable parameters that compensate the difference of the brightness are applied to the individual images in our new image processing method, it is possible to enhance the accuracy of the automatic image analysis method for sample slides with low asbestos concentration that caused errors in binary image processing. We demonstrated that enumeration of fibers by improved image processing algorithm remarkably enhanced the accuracy of HTM analysis in comparison with PCM. The improved HTM method can be a potential alternative to conventional PCM.

Phase Transition Characteristics in $Ge_xSb_{100-x}$ Film for Optical Storage Media

  • Park Tae-jin;Kang Myung-jin;Choi Se-young
    • 정보저장시스템학회:학술대회논문집
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    • 정보저장시스템학회 2005년도 추계학술대회 논문집
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    • pp.124-127
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    • 2005
  • Rewritable optical memory devices such as an CD-RW and DVD+RW are data storage media, which take advantage of the different optical properties in the amorphous and crystalline states of phase change materials. The switching property, structural transformation, transformation kinetics and chemical bindings of $Ge_xSb_{100-x}$($6{\le}x{\le}$34) were studied to investigate the feasibility of applying $Ge_xSb_{100-x}$ alloys in optical memory. The $Ge_xSb_{100-x}$ thin film was deposited by RF magnetron co-sputtering system and phase change characteristics were investigated by X-ray diffraction (XRD), static tester, inductively coupled plasma atomic emission spectrometer (ICP-AES) and atomic force microscopy (AEM). Optimum fiim composition of $Ge_xSb_{100-x}$ was studied and its minimum time fur laser induced crystallization and optical contrast fur phase transition was performed. These results might be correlated with the binding energies between Ge and Sb, and indicate that $Ge_xSb_{100-x}$ have an potential far optical memory applications.

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MOVPE of ZnSe with DIPSe and DMZn

  • Soo, Huh-Jeung;Ok, Lim-Jeong
    • Journal of Korean Vacuum Science & Technology
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    • 제2권2호
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    • pp.118-121
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    • 1998
  • Diisopropylselenide (DIPSe) is employed for the metalorganic vapor phase epitaxy (MOVPE) of ZnSe in order to eliminate premature gas phase reaction while maintaining negligible carbon incorporation and preserving relatively low growth temperature. In combination with dimethylzinc, single crystalline ZnSe layers were grown on GaAs at temperature around 450$^{\circ}C$. Secondary ion mass spectrometry showed a negligible carbon incorporation in ZnSe films grown from DIPSe even at high [Ⅵ]/[II] ratios, in contrast of a carbon concentration of 1021 cm-3 in ZnSe films grown from diallyselenide (DASe). Crystalline and interface quality are demonstrated by secondary electron microscopy, secondary ion mass spectroscopy and double crystal X-ray diffraction.

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PRAM 용 GST계 상변화 박막의 조성에 따른 특성 (Properties of GST Thin Films for PRAM with Composition)

  • 장낙원
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권6호
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    • pp.707-712
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    • 2005
  • PRAM (Phase change random access memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change materials have been researched in the field of optical data storage media. Among the phase change materials. $Ge_2Sb_2Te_5$ is very well known for its high optical contrast in the state of amorphous and crystalline. However the characteristics required in solid state memory are quite different from optical ones. In this study. the structural Properties of GeSbTe thin films with composition were investigated for PRAM. The 100-nm thick $Ge_2Sb_2Te_5$ and $Sb_2Te_3$ films were deposited on $SiO_2/Si$ substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films. x-ray diffraction (XRD). atomic force microscopy (AFM), differential scanning calorimetry (DSC) and 4-point measurement analysis were performed. XRD and DSC analysis result of GST thin films indicated that the crystallization of $Se_2Sb_2Te_5$ films start at about $180^{\circ}C$ and $Sb_2Te_3$ films Start at about $125^{\circ}C$.

PRAM용 GST계 박막의 조성에 따른 특성 (Properties of GST Thin Films for PRAM with Composition)

  • 정명훈;장낙원;김홍승;류상욱;이남열;윤성민;박영삼;이승윤;유병곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.203-204
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    • 2005
  • PRAM (Phase change Random Access Memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change material has been researched in the field of optical data storage media. Among the phase change materials $Ge_2Sb_2Te_5$(GST) is very well known for its high optical contrast in the state of amorphous and crystalline. However, the characteristics required in solid state memory are quite different from optical ones. In this study, the structural properties of GST thin films with composition were investigated for PRAM. The 100-nm thick GeTe and $Sb_2Te_3$ films were deposited on $SiO_2$/Si substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films, we performed x-ray diffraction (XRD) and atomic force microscopy (AFM).

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A Study on the Mechanical Properties of Duplex Stainless Steel Weldment According to Mo Contents

  • Bae, Seong Han;Lim, Hee Dae;Jung, Won Jung;Gil, Woong;Jeon, Eon Chan;Lee, Sung Geun;Lee, Hyo Jong;Kim, In Soo;Lee, Hae Woo
    • 대한금속재료학회지
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    • 제50권9호
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    • pp.645-651
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    • 2012
  • This study investigated changes in phase fraction caused by the addition of Mo, as well as the subsequent behaviour of N and its effect on the mechanical properties of welded 24Cr-N duplex stainless steel weld metals. Filler metal was produced by fixing the contents of Cr, Ni, N, and Mn while adjusting the Mo content to 1.4, 2.5, 3.5 wt%. The delta ferrite fraction increased as the Mo content increased. In contrast, the ${\gamma}$ fraction decreased and changed from a round to an acicular shape. Secondary austenite (${\gamma}^{\prime}$) was observed in all specimens in a refined form, but it decreased as the Mo content increased to the extent that it was nearly impossible to find any secondary austenite at 3.5 wt% Mo. Both tensile and yield strengths increased with the addition of Mo. In contrast, the highest value of ductility was observed at 1.41 wt% Mo. At all temperatures, impact energy absorption showed the lowest value at 3.5 wt% Mo, at which the amount of ${\delta}$-ferrite was greatest. There was no significant temperature dependence of the impact energy absorption values for any of the specimens. As the fraction of ${\gamma}$ phase decreased, the amount of N stacked in the ${\gamma}$ phase increased. Consequently, the stacking fault energy decreased, while the hardness of ${\gamma}$ increased.