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
(36)
(30)
(5)
(2)
In this work, the possibility of a multiwavelength mode-locked fiber laser generation based on Four-Wave Mixing (FWM) induced by Fe2O3-SiO2 nanocomposite material is investigated for the first time. A multiwavelength mode-locked pulses fiber laser are generated from Ytterbium–doped fiber laser (YDFL) due to the combined action of high nonlinear absorption and high refractive coefficients of Fe2O3-SiO2 nanocomposite incorporated inside YDFL ring cavity. Up to more than 20 lasing lines in the 1040–1070 nm band with an equally lines separation of ~0.6 nm have been observed by just simple variation of passive modulation of the state of the polarization and the pump power altogether. Moreover, a passively mode-locked operation of YDFL laser
... Show More
(5)
(3)
The aim of this research is to design and construct a semiconductor laser range finder
operating in the near infrared range for ranging and designation. The main part of the range finder is the
transmitter which is a semiconductor laser type GaAs of 0.904 mm wavelength with a beam expander,
and the receiver with its collecting optics. The characteristics of transmitter pulse width were 200ns and
threshold current 10 Amp. and maximum operating current 38 Amp. The repetition rate was set at 660 Hz
and maximum output power about 1 watt. The divergence of the beam was 0.268o. A special computer
code was used for optimum optical design and laser spot size analysis and for calculation of atmosphere
attenuation.
The objective of the present study is to verify the actual carious lesion depth by laser
fluorescence technique using 650 nm CW diode laser in comparison with the histopathological
investigation. Five permanent molar teeth were extracted from adult individuals for different reasons
(tooth impaction, periodontal diseases, and pulp infections); their ages were ranging from 20-25 years
old. Different carious teeth with varying clinical stages of caries progression were examined. An
experimental laser fluorescence set-up was built to perform the work regarding in vitro detection and
quantification of occlusal dental caries and the determination of its actual clinical carious lesion depth by
650 nm CW diode laser (excitat
The photoconductivity and its dependence on light intensity have been investigated in a-Ge20Se80 thin films as a function of temperature between (293–323)K. The result showed that the photoconductivity and photosensitivity increase with increase of annealing temperature. This behavior is interpreted in terms of the dispersive diffusion –controlled recombination of localized electrons and holes.
Temperature inside the vehicle cabin is very important to provide comfortable conditions to the car passengers. Temperature inside the cabin will be increased, when the car is left or parked directly under the sunlight. Experimental studies were performed in Baghdad, Iraq (33.3 oN, 44.4 oE) to investigate the effects of solar radiation on car cabin components (dashboard, steering wheel, seat, and inside air). The test vehicle was oriented to face south to ensure maximum (thermal) sun load on the front windscreen. Six different parking conditions were investigated. A suggested car cover was examined experimentally. The measurements were recorded for clear sky summer days started at 8 A.M. till 5 P.M.
... Show More