In humans, Pseudomonas aeruginosa is the second most frequent gram negative nosocomial pathogen in hospitals and has the highest case-fatality rate of all hospital-acquired bacteremia because of the hardy resistance of these bacteria to mechanical cleansing as well as to disinfectant, and many antibiotics. The susceptibility of bacteria against the antibiotics is modulated by several local factors such as temperature which modified drug efficacy, so this study was carried out to evaluate the effect of different temperature (20,42,45)Ċon the susceptibility of Pseudomonas aeruginosa to the minimum inhibitory concentrations (MIC) of the antimicrobial agents before and after irradiation. The samples collected from 150 persons suffering from burns-wounds infections, thirty-five isolates of pseudomonas aeruginosa bacteria were obtained depending on morphological and biochemical tests. Following exposure of Pseudomonas aeruginosa isolates to the diode laser with 805nm wavelength,3W output power and (5,10,15) minutes exposure times in combination with different temperature and different concentrations of ( cefotaxim, amikacin, chloramphenicol) antibiotics, highly observable change in the MIC value was achieved , the bacterial isolates became sensitive to chloramphenicol at the three exposure times and 100% killing of the cells was observed at 15 minutes exposure time at temperature 45Ċ in absence of the antibiotics. In conclusion, 3W diode laser in combination with temperature 45Ċ was the best condition that reduces the MIC value, and killing bacteria at 10 minutes exposure time.
Introduction
Since the last century, the laser occupied a large degree of attention in the scientific and technological fields. Invention of laser causes a chain of important changes in the science development especially in physics, chemistry, biology and electronics, in addition to its industrial and medical applications. For this reason the laser enters in many fields and introduces solution to many problems.
Many lasers have been used successfully for treating many cases of infection that caused by bacteria such as E.coli, Staphylococcus aureus and Pseudomonas aeruginosa. The resistance of Pseudomonas aeruginosa to many antibiotics form a big problem, especially in burns and wounds infections. Many studies have been introduced to investigate the effect of laser on microorganisms,a lotof their were related to the susceptibility of bacteria to antibiotics. This work is a trial in this regard.
Pseudomonas aeruginosa
One of the most common microorganisms encounted in hospital infection. It was isolated from various sources like air, floor, sinks and even disinfectant (Iglewski, 1980).
Pseudomonas aeruginosa is frequently present in
In this work, a CW CO2 laser was used for cutting samples of the fiber-reinforced
plastics (FRP) of three different types of reinforcing material; aramide, glass and carbon.
Cutting process was investigated throughout the variation of some parameters of cutting
process and their effects on cutting quality as well as the effect of an inert gas exist in the
interaction region and finally using a mechanical chopper in order to enhance the cutting
quality. Results obtained explained the possibility to perform laser cutting with high
quality in these materials by good control of the parameters and conditions of the process.
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In this work we investigate and calculate theoretically the variation in a number of optoelectronic properties of AlGaAs/GaAs quantum wire laser, with emphasis on the effect of wire radius on the confinement factor, density of states and gain factor have been calculated. It is found that there exist a critical wire radius (rc) under which the confinement of carriers are very weak. Whereas, above rc the confinement factor and hence the gain increase with increasing the wire radius.
Semiconductor laser is used in processing many issues related to the scientific, military, medical, industrial and agricultural fields due to its unique properties such as coherence and high strength where GaN-based components are the most efficient in this field. Current technological developments mention to the strong connection of GaN with sustainable electronic and optoelectronic devices which have high-efficiency. The threshold current density of Al0.1Ga0.9N/GaN triple quantum well laser structure was investigated to determine best values of the parameters affecting the threshold current density that are well width, average thickness of active region, cavity length, reflectivity of cavity mirrors and optical confinement factor. The opt
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Fluorescence excitation by Nd:YAG pumped dye laser and single vibrational level fluorescence
spectra of 1,3 benzodioxole in a supersonic jet have been obtained and interpreted. The previous assignment of
the 0 0
0 band was incorrect. In addition, many other bands involving n20 and n19 vibrations of a2 symmetry were
confirmed. As far as a1 totally symmetric vibration is concerned. The n14 was assigned to be located in the fivemembered
ring whereas n13 seem to be located in the benzene ring as a result of the electronic transition in the
benzene ring which affects n13 and not n14 wavenumber.
Verrucae vulgares are commonly encountered. The present work is designed in an attempt to build a systematic procedure for treating warts by carbon dioxide laser regarding dose parameters, application parameters and laser safety.
Patients and Methods: The study done in the department of dermatology in Al-Najaf Teaching Hospital in Najaf, Iraq. Forty-two patients completed the study and follow up period for 3 months. Recalcitrant and extensive warts were selected to enter the study. Carbon dioxide laser in a continuous mode, in non-contact application, with 1 mm spot size was used. The patients were divided into two groups. The first group of patients consisted of 60 lesions divided to 6 equal groups, in whom we use different outputs a
The objective of this paper was to study the laser spot welding process of low carbon steel sheet. The investigations were based on analytical and finite element analyses. The analytical analysis was focused on a consistent set of equations representing interaction of the laser beam with materials. The numerical analysis based on 3-D finite element analysis of heat flow during laser spot welding taken into account the temperature dependence of the physical properties and latent heat of transformations using ANSYS code V.10.0 to simulate the laser welding process. The effect of laser operating parameters on the results of the temperature profile were studied in addition to the effect on thermal stresses and dimensions of the laser w
... Show MoreBackground: Acne is a common disorder experienced by adolescents and persists into adulthood in approximately 12%–14% of cases with psychological and social implications of high gravity. Fractional resurfacing employs a unique mechanism of action that repairs a fraction of skin at a time. The untreated healthy skin remains intact and actually aids the repair process, promoting rapid healing with only a day or two of downtime. Aims: This study, was designed to evaluate the safety and effectiveness of fractional photothermolysis (fractionated Er: YAG laser 2940nm) in treating atrophic acne scars. Methods: 7 females and 3 males with moderate to severe atrophic acne scarring were enrolled in this study that attained private clinic for Derm
... Show MoreThe present study includes a theoretical treatment to derive the general equations of pumping threshold power ( ), laser output power (Pout), and laser device efficiency (ƞ) of the element-doped thin-disk laser (Yb3+) with a quasi-three-level pumping scheme in the continuous wave mode at a temperature of (299K°). In this study, the host crystals (YAG) were selected as typical examples of this laser design in a Gaussian transverse mode. The numerical solution of these equations was made using Matlab software by selecting the basic parameters from the recently published scientific articles for the laser design of these crystal hosts. According to this simulation, this article studied the effect o
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This study investigates the digestion of cow dung (CD) for biogas production at laboratory scales. The study was carried out through anaerobic fermentation using cow dung as substrate. The digester was operated at ambient temperatures of 39.5 °C for a period of 10 days. The effect of iron powder in controlling the production of hydrogen sulfide (H2S) has been tested. The optimum concentration of iron powder was 4g/L with the highest biogas production. A Q – swatch Nd:YAG laser has been used to mix and homogenize the components of one of the six digesters and accelerate digestion. At the end of digestion, all digestions effluent was subjected to 5 laser pulses with 250mJ/pules to dispose waste biomass.
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