Introduction: Photodynamic inactivation has been developed to kill pathogenic microbes. In addition, some techniques have been introduced to minimize the biofilm resistance to antifungal properties in inhibiting cell growth. The principle of photodynamic inactivation different to antifungal drugs therapy which is resistant to biofilms. The presence of reactive oxygen species (ROS) that generating in photodynamic inactivation mechanisms can be damaging of biofilm cells and the principle of light transmission that could be penetrating in matrix layers of extracellular polymeric substance (EPS) until reaching the target cells at the base layers of biofilm. The present work aims to explore the potential of chlorophyll extract of papaya leaf as an exogenous photosensitizer to kill the Candida albicans biofilms after being activated by the laser. The potential of chlorophyll photosensitizer was evaluated based on the efficacy of inactivation C. albicans biofilm cell through a cell viability test and an organic compound test. Methods: The treatment of photoinactivation was administered to 12 groups of C. albicans biofilm for four days using the 445 nm laser and the 650 nm laser. The 445 nm and 650 nm lasers activated the chlorophyll extract of the papaya leaf (0.5 mg/L) at the same energy density. The energy density variation was determined as 5, 10, 20, 30 and 40 J/cm2 with the duration of exposure of each laser adjusted to the absorbance percentage of chlorophyll extract of the papaya leaf. Results: The absorbance percentage of chlorophyll extracts of the papaya leaf on wavelengths of 650 nm and 445 nm respectively were 22.26% and 60.29%, respectively. The most effective treated group was a group of the laser with the addition of chlorophyll, done by the 650 nm lasers with inactivation about 32% (P=0.001), while the 445 nm lasers only 25% (P=0.061). The maximum malondialdehyde levels by treatment of the laser 650 nm were (0.046±0.004) nmol/mg. Conclusion: The use of chlorophyll extract of the papaya leaf as a photosensitizer, resulted in the maximum spectrum of absorption at 414 nm and 668 nm, which produced a maximum reduction effect after photoinactivation up to 32% (with chlorophyll) and 25% (without chlorophyll). The utilization of chlorophyll extract of the papaya leaf would increase the antifungal effects with the activation by the diode laser in the biofilm of C. albicans

Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm 2. The results show that exposure to laser with energy dose of 7.18 J/cm 2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

Candida albicans is a normal flora caused fungal infections and has the ability to form biofilms. The aim of this study was to improve the antifungal effect of silver nanoparticles (AgNPs) and the light source for reducing the biofilm survival of C. albicans. AgNPs were prepared by silver nitrate (AgNO 3) and trisodium citrate (Na 3 C 6 H 5 O 7). To determine the antifungal effect of treatments on C. albicans biofilm, samples were distributed into four groups; L + P+ was treatment with laser irradiation and AgNPs; L + P− was treatment with laser irradiation only; L − P+ was treatment with AgNPs only (control positive); L − P− was no treatment with laser irradiation or AgNPs (control negative). The growth of fungi had been monitored by measuring the optical density at 405 nm with ELISA reader. The particle size of AgNPs was measured by using (particle size analyzer) and the zeta potential of AgNPs was measured by using Malvern zetasizer. The PSA test showed that the particle size of AgNPs was distributed between 7.531-5559.644 nm. The zeta potentials were found lower than − 30 mV with pH of 7, 9 or 11. The reduction percentage was analyzed by ANOVA test. The highest reduction difference was given at a lower level irradiation because irradiation with a density energy of 6.13 ± 0.002 J/cm 2 resulted in the biofilm reduction of 7.07 ± 0.23% for the sample without AgNPs compared to the sample with AgNPs that increased the biofilm reduction of 64.48 ± 0.07%. The irradiation with a 450nm light source had a significant fungicidal effect on C. albicans biofilm. The combination of light source and AgNPs provides an increase of biofilm reduction compared to the light source itself.

We consider two-dimensional numerical simulation of a tandem configuration of both I-shape cylinder and circular cylinder. Diameter of circular cylinder is D as the bluff body and I-shaped cylinder has diameter of d with a cutting angle 53 o as passive control, that is located in front of the bluff body. Navier Stokes equations are used to solve this problem and solved with a finite difference method. When we put the Reynolds number of R e = 7 × 10 3 , the domain distance between bluff body and passive control is a 0.6 ≤ S/D ≤ 3.0 and X/D = 2.0 then we obtain profile streamline around the bluff body, pressure distribution, separation point on the top around the 65 o and on the bottom around 285 o , wake and mathematics models of drag coefficient.

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