We report an ultra-long Raman laser that implemented a variable pumping scheme in backward and forward configurations. Rayleigh backscattering effects were realized in the 51 km fiber length that functioned as a virtual mirror at one fiber end. With the employment of a fiber Bragg grating that has a peak reflection wavelength at 1553.
View Article and Find Full Text PDFThis study assessed the anisakid nematode distribution pattern in the fish collected from coasts of Mediterranean Sea, Egypt, during the period September 2010-April 2011. Two hundred thirty out of 300 (76.7%) Dicentrarchus labrax (European seabass) marine fishes belonging to family Moronidae were dissected and found to be infected with larva three nematodes.
View Article and Find Full Text PDFSilver nanoparticles were fabricated by ablation of a pure silver plate immersed in castor oil. A Nd:YAG-pulsed Q-switch laser with 1064-nm wavelength and 10-Hz frequency was used to ablate the plate for 10 minutes. The sample was characterized by ultraviolet-visible, atomic absorption, Fourier transform-infrared spectroscopies, and transmission electron microscopy.
View Article and Find Full Text PDFObjective: To maximize prevention of mother-to-child transmission of HIV (PMTCT) effectiveness and increase identification of HIV status in maternity units in Swaziland.
Design: With a quasi-experimental design, 3 maternity units were randomly assigned to the training intervention and 3 units were controls.
Methods: Targeted on-site training was provided to nurse-midwives in intervention sites.
We implement a particle swarm optimization (PSO) algorithm to characterize stimulated Brillouin scattering phenomena in optical fibers. The explicit and strong dependence of the threshold exponential gain on the numerical aperture, the pump laser wavelength and the optical loss coefficient are presented. The proposed PSO model is also evaluated with the localized, nonfluctuating source model and the distributed (non-localized) fluctuating source model.
View Article and Find Full Text PDFWe demonstrate a multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing. The wider channel spacing is realized by circulating the odd-order Stokes signals in the Brillouin gain medium through a four-port circulator. The circulated odd-order Stokes signals are amplified by the Brillouin gain and thus produce even-order Stokes signals at the output.
View Article and Find Full Text PDFLaser ablation of a silver plate immersed in virgin coconut oil was carried out for fabrication of silver nanoparticles. A Nd:YAG laser at wavelengths of 1064 nm was used for ablation of the plate at different times. The virgin coconut oil allowed formation of nanoparticles with well-dispersed, uniform particle diameters that were stable for a reasonable length of time.
View Article and Find Full Text PDFIn this study we used a laser ablation technique for preparation of silver nanoparticles. The fabrication process was carried out by ablation of a silver plate immersed in palm oil. A pulsed Nd:YAG laser at a wavelength of 1064 nm was used for ablation of the plate at different times.
View Article and Find Full Text PDFIntroduction: Enlargement of the thymus following remission of a cancer treated by chemotherapy poses a problem of differential diagnosis between benign thymic hyperplasia and relapse of a mediastinal tumour.
Case Report: We report the case of a thymic tumour developing 6 months after chemotherapy for ovarian cancer in a woman of 31 years. Because of the risk of a mediastinal recurrence, the patient was submitted to thymectomy by mediastinotomy.
We develop a theoretical model that can be used to predict stimulated Brillouin scattering (SBS) threshold in optical fibers that arises through the effect of Brillouin pump recycling technique. Obtained simulation results from our model are in close agreement with our experimental results. The developed model utilizes single mode optical fiber of different lengths as the Brillouin gain media.
View Article and Find Full Text PDFOut of 2,343 examined sheep throughout the whole year, 271 were found to be infected with tapeworms (11.5%). The highest infection rate (22.
View Article and Find Full Text PDFFabry disease is a rare, X-linked lysosomal storage disorder that leads to accumulation of globotriaosylceramide in different tissues of the body. The disease is progressive and the first symptoms usually present in childhood. Consequences of the disease are disability and premature death.
View Article and Find Full Text PDFWe demonstrate a simple configuration for generating a double Brillouin frequency shift through the circulation of an odd-order Brillouin Stokes signal. It is operated based on cascaded Brillouin scattering in single-mode optical fibers that behave as the Brillouin gain media. A four-port circulator is incorporated into the setup to circulate the odd-order Brillouin Stokes signal in the fiber.
View Article and Find Full Text PDFWe demonstrate the generation of multiple Brillouin Stokes lines generation assisted by Rayleigh scattering in Raman fiber laser. The linear cavity is utilized to take advantage of the Rayleigh scattering effect, and it also produces two strong spectral peaks at 1555 and 1565nm. Under a strong pumping condition, the Rayleigh backscatters contribute to the oscillation efficiency, which increases the Brillouin Stokes lines intensity between these two wavelength ranges.
View Article and Find Full Text PDFAn all-optical generation of a microwave carrier at 21 GHz that incorporates a double-Brillouin frequency shifter is presented. The frequency shift of approximately 21 GHz is achieved by generating the second-order Brillouin Stokes signal from the Brillouin pump. This is accomplished through the circulation and isolation of its first-order Stokes signal in the optical fiber.
View Article and Find Full Text PDFNijmegen Breakage syndrome is a rare, autosomal recessive disorder characterized by severe, combined immunodeficiency, recurrent sinopulmonary infections, chromosomal instability, radiosensitivity, predisposition to malignancy, a "bird-like" facial appearance, progressive microcephaly, short stature, and mental retardation. The syndrome is caused by mutations in the NBS1 gene, which encodes a DNA-repair protein, named nibrin. The authors summarize current knowledge on molecular genetics, diagnostic characteristics and therapeutic options of this inborn error of innate immunity.
View Article and Find Full Text PDFNeonatal diabetes mellitus is considered a rare disease that is diagnosed in the first six months of life, and can be either transient or permanent. Recent advances in molecular genetics have shown that activating mutations in KCNJ11 (the gene that encodes for the Kir6.2 subunit of the K ATP potassium channel of the pancreatic beta-cell) is a common cause of permanent neonatal diabetes mellitus.
View Article and Find Full Text PDFFabry disease is a rare, X-linked lysosomal storage disorder that leads to accumulation of globotriaosylceramide in different tissues of the body. The disease is progressive, first symptoms usually present in childhood. Consequencies of the diseases are disability and premature death.
View Article and Find Full Text PDFBackground: On surgical simulators, measures of economy of hand motion have been shown to be reliable, valid, and objective measures of technical competence. Our goal was to validate hand-motion analysis (HMA) as an objective measure of surgical skill on real patients.
Methods: HMA (hand movement frequency, hand travel distance) was evaluated serially on 2 standardized, live patient surgeries (vasectomy, vasectomy reversal) for both a novice and experienced surgeon.
Purpose: Selecting a surgical approach for correction of ureteropelvic junction obstruction in children is mostly driven by surgeon preference, and includes laparoscopy, flank incision and dorsal lumbotomy. Comparative analyses focusing on operative time, hospital stay and complications are lacking.
Materials And Methods: We retrospectively reviewed the charts of 41 consecutive patients older than 3 years who underwent laparoscopic pyeloplasty by a single surgeon between 2005 and 2008.
Background: Diabetic ketoacidosis (DKA) has significant morbidity and mortality, and is common at diagnosis in children.
Objective: Describe the frequency and severity of DKA at diagnosis of type 1 diabetes mellitus (T1DM) in children in Kuwait.
Methods: Hospital records of 677 diabetic children less than 12 yr of age, diagnosed during the period of 2000-2006 were reviewed.
We report experimental results demonstrating the variation of optical signal-to-noise ratio (OSNR) of laser lines in Brillouin-Raman fiber laser against Raman pump power (RPP) variation. The reduction of OSNR is attributed to the spectral broadening of laser lines depending on the RPP. The spectral broadening is owing to the effect of the interaction between laser lines and turbulent waves (nonlinear interaction between longitudinal cavity modes).
View Article and Find Full Text PDFThe operation of a single-wavelength Brillouin-erbium fiber laser (BEFL) system with a Brillouin pump preamplified technique for different output coupling ratios in a ring cavity is experimentally demonstrated. The characteristics of Brillouin Stokes power and tunability were investigated in this research. The efficiency of the BEFL operation was obtained at an optimum output coupling ratio of 95%.
View Article and Find Full Text PDFWe have investigated the characteristics of Brillouin-Erbium fiber laser (BEFL) with variation of Erbium-doped fiber amplifier (EDFA) locations in a ring cavity configuration. Three possible locations of the EDFA in the laser cavity have been studied. The experimental results show that the location of EDFA plays vital role in determining the output power and the tuning range.
View Article and Find Full Text PDF