360 research outputs found

    Prevalence, Pathogenicity, Virulence, Antibiotic Resistance, and Phylogenetic Analysis of Biofilm-Producing Listeria monocytogenes Isolated from Different Ecological Niches in Egypt: Food, Humans, Animals, and Environment

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    Serious outbreaks of foodborne disease have been caused by Listeria monocytogenes found in retail delicatessens and the severity of disease is significant, with high hospitalization and mortality rates. Little is understood about the formidable public health threat of L. monocytogenes in all four niches, humans, animals, food, and environment, in Egypt. This study analyzed the presence of L. monocytogenes collected from the four environmental niches and bioinformatics analysis was implemented to analyze and compare the data. PCR was used to detect virulence genes encoded by pathogenicity island (LIPI-1). prfA amino acid substation that causes constitutive expression of virulence was common in 77.7% of isolates. BLAST analysis did not match other isolates in the NCBI database, suggesting this may be a characteristic of the region associated with these isolates. A second group included the NH1 isolate originating in China, and BLAST analysis showed this prfA allele was shared with isolates from other global locations, such as Europe and North America. Identification of possible links and transmission pathways between the four niches helps to decrease the risk of disease in humans, to take more specific control measures in the context of disease prevention, to limit economic losses associated with food recalls, and highlights the need for treatment options

    Method of double averaging for modeling PFC switching converters

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    Author name used in this publication: S. C. WongAuthor name used in this publication: C. K. TseAuthor name used in this publication: M. OrabiAuthor name used in this publication: T. NinomiyaRefereed conference paper2003-2004 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    The method of double averaging : an approach for modeling power-factor-correction switching converters

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    Author name used in this publication: Chi K. Tse2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Hydrogen production using Al-Sn alloys prepared by rapid solidification

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    Air pollution produced by the direct burning of fossil fuels is a serious problem. Therefore, there is a vital demand for renewable and clean fuel replacements for future energy source. Hydrogen, which exhibits high calorific value and is a clean burning product, could be the first choice in the future, as it is a good-looking fuel for fuel cells where the electric energy is directly gotten by the electrochemical reactions of hydrogen and oxygen. Rapidly solidified Al100-x-Snx alloy X= (0, 25, 55, 75 all in wt.%) was prepared using melt spinning technique at 800 ÂÂșC. The structural and microstructural evolutions of the phases have been studied using X-ray powder diffraction (XRD) and the Rietveld method. Al45Sn55 alloy shows the best volume of hydrogen generation which is (531 ml), this alloy has the highest number of grains (1096) than other prepared alloys in its surface which examined through a Scanning electron microscope (SEM) and analyzed using an SPM data visualization and analysis tool (Gwyddion 2.32). Differential thermal analysis (DTA) was used for calculating melting temperature for all prepared alloys. Melting temperature reduced from 933.47 K for Al pure to 500.95 K in Al45Sn55 alloy. Temperature dependence of resistivity had been performed for all prepared alloys. Electrical properties of prepared alloys show the decrease in volume of the unit cell V with increasing VEC, which means that the volume of the first Brillouin zone increases by increasing VEC since they are inversely proportional to each other

    The method of double averaging: an approach for modeling power-factor-correction switching converters

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    Local versus nonlocal αα\alpha\alpha interactions in 3α3\alpha description of 12^{12}C

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    Local αα\alpha \alpha potentials fail to describe 12^{12}C as a 3α3\alpha system. Nonlocal αα\alpha \alpha potentials that renormalize the energy-dependent kernel of the resonating group method allow interpreting simultaneously the ground state and 02+0^+_2 resonance of 12^{12}C as 3α3\alpha states. A comparison with fully microscopic calculations provides a measure of the importance of three-cluster exchanges in those states.Comment: The tar.gz file has 1 tex file and 1 eps fil

    Cylindrical shells under uniform bending in the framework of Reference Resistance Design

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    The resistance of cylindrical shells and tubes under uniform bending has received significant research attention in recent times, with a number of major projects aiming to characterise their strength through both experimental and numerical studies. However, the investigated cross-section slenderness ranges have mostly addressed low radius to thickness ratios where buckling occurs after significant plasticity and the influence of geometric imperfections is relatively minor. The behaviour under uniform bending of thinner imperfection-sensitive cylinders that fail by elastic buckling was largely omitted, as was the influence of finite length effects. The value of such resistance models that are only useful for thicker cylinders is therefore somewhat limited.This paper offers the most comprehensive known characterisation of the buckling and collapse resistance of isotropic cylindrical shells and tubes under uniform bending. Expressed within the modern framework of Reference Resistance Design (RRD), it holistically incorporates the effects of material plasticity, geometric nonlinearity and sensitivity to realistic and damaging weld depression imperfections. The characterisation was made possible by the authors’ recently-developed novel methodology for mass automation of nonlinear shell buckling finite element analyses. A modification of the RRD formulation is proposed which facilitates its application to systems of low slenderness, and offers a compact algebraic characterisation of all potential imperfection amplitudes for this common shell structural condition. A reliability analysis is also performed.<br/

    Epidemiological Insights of Foot and Mouth Disease Virus Infection among Cattle and Buffaloes in Sharkia Governorate, Egypt

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    Foot-and-mouth disease (FMD) is endemic in Egypt and in most parts of Africa causing huge economic losses. Control of FMD using vaccination requires information on the occurrence of various FMDV serotypes. This study aimed to determine the prevalence of FMDV serotypes in Sharkia Governorate, Egypt. A total number of 643 different samples, within ten different localities, were collected from both cattle and buffaloes (n = 283) of different, age, sex, immune status against FMD, and health status. Field samples (n = 360) have been screened for FMDV by RT-PCR using universal primers and were further subtyped using serotype-specific primers. Additionally, serum samples (n = 283) have been analyzed by applying FMDV serotype-specific antibody ELISA. The RT-PCR screening revealed that a total number of 39/283 (13.8%), 61/283 (21.6%) and 17/38 (44.7%) animals were positive for FMDV serotype O, A and SAT2, respectively. While, by ELISA, neutralizing antibodies directed against FMDV serotype O, A, and SAT2, were found in 177/283 (62.5%), 171/283 (60.4%) and 27/38 (71.1%) serum samples, respectively. These results indicated the endemic status of the FMDV serotypes O, A and SAT2 in Sharkia Governorate despite routine FMD vaccination programs. Although many variations of disease prevalence were recorded between animals of different, age, sex and immune and health status but it was obvious that FMD was more prominent and prevalent in buffaloes (47.1%) than in cattle (34.1%). Therefore, control efforts should focus on reducing the circulation of FMDV among susceptible livestock with special attention towards water buffaloes. Continuous surveillance, at molecular and immunological levels, of FMDV serotypes is needed for the effectiveness of any adopted control strategy targeting FMD including vaccination

    Outcomes of Endolymphatic Sac Surgery for Meniere’s Disease with and without Comorbid Migraine

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    Purpose. To explore outcomes of endolymphatic sac surgery for patients with Meniere’s disease with and without the comorbid condition of migraine. Materials and Methods. A retrospective chart review of adult patients undergoing endolymphatic sac surgery at a single tertiary care center from 1987 to 2019 was performed. All adult patients who failed medical therapy and underwent primary endolymphatic sac surgery were included. The main outcome measures were vertigo control and functional level scale (FLS) score. Patient characteristics, comorbidities, and audiometric outcomes were tracked as well. Results. Patients with Meniere’s disease and migraine had a stronger association with psychiatric comorbidities (64.29% vs. 25.80%, p = 0.01), shorter duration of vertigo episodes (143 vs. 393 min, p = 0.02), and younger age (36.6 vs. 50.8 yr, p = 0.005) at the time of endolymphatic sac surgery. Postoperative pure tone averages and word recognition scores were nearly identical to preoperative baselines. Class A vertigo control (47.92%) was most common, followed by class B vertigo control (31.25%). The FLS score improved from 4.2 to 2.8 (p \u3c 0.001). Both patients with and without migraine had classes A-B vertigo control (66.67% vs. 80.95%) without any statistically significant difference (p = 0.59). Of the patients who required secondary treatment (10.42%), none had migraine. Conclusions. Endolymphatic sac surgery is an effective surgical intervention for Meniere’s disease with and without migraine. Patients with comorbid migraine tend to be younger and present with psychiatric comorbidities
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