• Journal of Digital Convergence
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• v.12 no.6
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• pp.407-414
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• 2014

The aim of this study was to evaluate the photodynamic therapy effects against staphylococci using Photofrin and Radachlorin with Light emitting diode(LED). Experimental methods, The bacterial suspensions containing Staphylococcus aureus and Staphylococcus epidermidis at $1{\times}10^5$ were prepared and diluted to different concentrations of photosensitizer, Photofrin or Radachlorin, on 1.25, 2. 5,5 and $10{\mu}g/ml$. The bacterial suspensions were exposed to 630 and 670 nm LED light at the energy density of 14.4 and $19.8J/cm^2$, respectively. The CFU results of S. aureus and S. epidermidis were showed 33 and 50 colony forming at $5{\mu}g/ml$ of Photofrin, respectively and both of them perfectely were dead at $5{\mu}g/ml$ of Radachlorin. The fluorescent intensity by flow cytometry was showed the increase in the dead cells than the normal cells. In the TEM photograph, the damage of bacterial membrane and the distortion of cell morphology were observed. These results suggest that photodynamic therapy combine with Photofrin and Radachlorin can be applied a new modality for antibacterial therapy.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.314-321
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• 2013

Photodynamic therapy(PDT) has been recommended as an alternative therapy for various diseases including microbial infection. The aim of the present study is to evaluate the antimicrobial effect of PDT using a photofrin and home made 630 nm Light emitting diode(LED) against Staphylococci. To examine the antimicrobial effect of photofrin-mediated PDT against Staphylococcus aureus and Staphylococcus epidermidis colony forming units(CFU) quantification, and bacterial viability using flow cytometry were formed. The CFU quantification results of S. aureus and S. epidermidis were 1 cfu/ml and 16 cfu/ml of average, respectively, after PDT application with photofrin of $50{\mu}g/m{\ell}$ and 630 nm LED and energy density of $18J/cm^2$. In addition, S. aureus and S. epidermidis isolates yielded forward-scatter (FSC) and fluorescence intensity (FI) differences on flow cytometry (FCM) after PDT. S. aureus and S. epidermidis cell size(FSC) increased 8.96% and 5.55% respectively, after PDT. Also the numbers of dead cell of S. aureus and S. epidermidis were a 39% and 61% incerased. These results suggest that photofrin-mediated PDT can be an effective alternative treatment for antibacterial therapy.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.1
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• pp.38-44
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• 2004

An experimental study for a crane hook was performed to investigate the stress distribution along a certain line where the maximum and minimum stresses to be developed. On this line, the isoclinic fringe and/or principal stress direction is constant. The crane hook was modeled into a 2-dimensional plate made of urethane rubber called 'Photoflex' The Photoflex is very sensitive to a load and has low photoelastic fringe constant. The Tardy compensation method with the fringe sharpening process and the 4-step phase shifting method, was used for the photoelastic technique. Experimental results by photoelasticity were compared with the calculated stresses from the simple curved beam theory and tile finite element analysis. Ail the results were close to each other.