The effect of 532nm Diode Pumped Solid State (DPSS) laser at power density of 5.234 W/cm2 on the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus was evaluated. These bacteria were isolated from samples taken from burn and infected wound areas of 55 patients admitted to the burn-wound unit in Al-Kindy teaching hospital in Baghdad during the period from October 2012 to March 2013. Each isolate was identified using microscopic, cultural and biochemical methods. A standard bacterial suspension was prepared for each isolate. Serial dilutions were then prepared and a dilution of 10-5 was selected. Irradiation experiments included four groups: (L-P-) bacterial suspension in saline solution, (L-P+) bacterial suspension in the presence of 0.1mg/ml photosensitizer (safranin O), (L+P-) bacterial suspension treated with laser radiation only and finally (L+P+) bacterial suspension treated with laser radiation in the presence of the photosensitizer. After irradiation, Cetrimide agar (P. aeruginosa) and Mannitol salt agar (S.aureus) were used. Seven replicates were used for each experimental group. Different times of exposure were applied for irradiated groups. The results revealed that twenty two isolates out of 70 samples were positive for P. aeruginosa (31%) and fifteen isolates out of 35 samples were positive for S. aureus (42%). The combined effect of DPSS laser and safranine O was significantly effective in reducing the number of Colony Forming Units per milliliter (CFU/ml) of P. aeruginosa and S. aureus compared with control groups. Almost a complete bacterial mortality achieved at 25 and 5 minutes of exposing to laser light in the presence of safranin O for P. aeruginosa and S. aureus respectively, suggesting that singlet oxygen (O2*) and/or reactive oxygen species (ROS) were involved in the killing of the bacteria.
Introduction:Visceral leishmaniasis (VL), also known as kala-azar, is a diffuse protozoan infection caused by Leishmania donovani complex. VL is principally caused by L. donovani and L. infantum (synonym L. chagasi in South America). The parasite targets the reticulo-endothelial system, with penetration of the spleen, liver, bone marrow and lymph nodes lead to organomegaly and pancytopenia. Organic pentavalent antimonials have been the first-line drugs for the therapy of leishmaniasis for the latest six decades, and clinical resistance to these drugs has emerged as a primary obstacle to successful treatment and control. Miltefosine has been shown to be higher or equivalent to presently approved essential medicines for at least one of viscer
... Show MoreABSTRACT Background: resin cement type and intraoral temperature fluctuations may affect the fracture performance of successful zirconia restorations. To fill this gap, the purpose of this study is to evaluate and compare the influence of thermocycling on fracture resistance and mode of failure of monolithic zirconia crowns luted with Rely X™ U200 and BreezeTMself-adhesive resin cements as well as imply the effect of adding 2 % of polylysine (PLS) to these cements. Materials: 64 maxillary premolars were milled out of zirconia blocks using CAD/CAM milling system. They were divided into four groups (n = 16) according to the cement type. Four different resin cements were used (RelyXTMU200, Breeze™, RelyX™ U200 with 2 % PLS
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One of the most important virulence factors in Pseudomonas aeruginosa is biofilm formation, as it works as a barrier for entering antibiotics into the bacterial cell. Different environmental and nutritional conditions were used to optimize biofilm formation using microtitre plate assay by P. aeruginosa. The low nutrient level of the medium represented by tryptic soy broth (TSB) was better in biofilm formation than the high nutrient level of the medium with Luria Broth (LB). The optimized condition for biofilm production at room temperature (25 °C) is better than at host temperature (37 °C). Moreover, the staining with 0.1% crystal violet and reading the biofilm with wavelength 360 are considered essential factors in
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In this work we study the influence of the laser pulse energy and ablation time on the aluminum nanoparticles productivity during nanosecond laser ablation of bulk aluminum immersed in liquid.
Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol for 3-8 minutes using the 1064 nm wavelength of a Nd:YAG laser with energies of 300-500 mJ per pulse.The laser energy was varied between 300 and 500 mJ/pulse, whereas the ablation time was set to 5 minutes. UV-Visible absorption spectra was used for the characterization and comparison of products.
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In this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate) on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m3 of Ca(OH)2 and 2 and 3 kg/m3 of Na2CO3 were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were comp
... Show MoreThis study shows how the structural and dielectric properties of (SnO2)1-x(Mn2O3)x, (where x=0.00, 0.03, 0.05,0.07, and 0.09) prepared using the solid state reaction technique, are affected by the doping of semiconducting metal oxide Mn2O3. Structural analysis of the composites was carried out using information from the composite samples obtained from X-ray diffraction (XRD). The diffraction peak shifting in XRD patterns indicated that Mn ions were successfully incorporated into the SnO2 crystal lattice. Mn ions were successfully doped in the Tin oxide matrix lattice with the subsequent increase of doping levels. The average crystal size evaluated using Scherrer's equation was found to vary from 33 to 37 nm, and the lattice constant
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