148 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

    Impacts of Denial-of-Service Attack on Energy Efficiency Pulse Coupled Oscillator

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    The Pulse Coupled Oscillator (PCO) has attracted substantial attention and widely used in wireless sensor networks (WSNs), where it utilizes firefly synchronization to attract mating partners, similar to artificial occurrences that mimic natural phenomena. However, the PCO model might not be applicable for simultaneous transmission and data reception because of energy constraints. Thus, an energy-efficient pulse coupled oscillator (EEPCO) has been proposed, which employs the self-organizing method by combining biologically and non-biologically inspired network systems and has proven to reduce the transmission delay and energy consumption of sensor nodes. However, the EEPCO method has only been experimented in attack-free networks without considering the security elements which may cause malfunctioning and cyber-attacks. This study extended the experiments by testing the method in the presence of denial-of-service (DoS) attacks to investigate the efficiency of EEPCO in attack-based networks. The result shows EEPCO has poor performance in the presence of DoS attacks in terms of data gathering and energy efficiency, which then concludes that the EEPCO is vulnerable in attack-based networks

    CHEMICAL PROFILE OF TWO JASMINUM SAMBAC L. (AIT) CULTIVARS CULTIVATED IN EGYPT–THEIR MEDIATED SILVER NANOPARTICLES SYNTHESIS AND SELECTIVE CYTOTOXICITY

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    Objective: Evaluation of two Jasminum sambac L. (Ait) cultivars; Arabian Nights (JSA) and Grand Duke of Tuscany (JSG) ethanolic leaves extracts as reducing agents for the green synthesis of silver nanoparticles (AgNPs) and evaluation of their cytotoxicity against MCF-7 breast cancer and 5637 bladder cancer cell lines and chemical profiling of the two cultivars. Methods: The synthesis of silver nanoparticles (AgNPs) by the two cultivars and characterization of AgNPs by ultraviolet (UV)–visible spectroscopy, Transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). Additionally, the use of The high-performance liquid chromatography coupled with photodiode array-mass-mass-spectroscopy (HPLC-PDA-MS/MS) for chemical profiling of both cultivars and evaluation of total leaves extracts and corresponding nanoparticles towards MCF-7 and 5637 cell lines compared to aneuploidy immortal keratinocyte (Ha Cat) normal cells by neutral cell assay. Results: The green synthesized AgNPs (of an average size range of 8.83 and 11.24 nm for JSA and JSG, respectively) exhibited cytotoxicity against MCF-7 and 5637 cell lines. The IC50 was determined for each total extract JSA (15.29±2.16 μg/ml) and JSG (20.28±1.20 μg/ml) and corresponding AgNPs 17.32±2.22 μg/ml and 6.32±1.01μg/ml for JSA and JSG, respectively. The IC50 of JSA and JSG against 5637 bladder cancer cell line were 13.76±1.11 μg/ml and 50.69±3.75 μg/ml, while the corresponding AgNPs showed IC50 of 5.54±0.88 μg/ml and 27.89±2.84 μg/ml, respectively. The HPLC-PDA-MS/MS allowed the identification of 59 compounds; 10 simple phenols, 17 flavonoids; quercetin and kaempferol glycosides, 2 lignans, and 30 secoiridoids; oleuropein, molihauside, and sambacoside. Conclusion: This study proved that JSA is an excellent source for the synthesis of AgNPs with optimum characters and enhanced activities toward MCF-7 and 5637 cell lines in correlation to identified compounds

    Radiation pattern reconfigurable fm antenna

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    In this work, a radiation pattern reconfigurable antenna design using compact printed spiral monopoles that operates at 102 MHz is reported. The proposed antenna changes its radiation behaviour that responds towards a desired direction with the use of RF switches. The antenna is printed on a 76.6mm × 50mm PCB layer providing more than 20MHz bandwidth at -10 dB threshold and is easily fabricated with low manufacturing cost. The antenna was also simulated on 500mm × 500mm ground plane that represents the roof top of a vehicl

    Chemical composition, antioxidant and hepatoprotective activities of methanol extracts from leaves of Terminalia bellirica and Terminalia sericea (Combretaceae)

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    Background Plants belonging to the genus Terminalia such as Terminalia bellirica and Terminalia sericea are used traditionally to treat several diseases and health disorders. Up to this date, the roots of Terminalia sericea and the fruits of Terminalia bellirica are the mostly studied plant parts. The phytochemical composition and the biological activities of the leaves of both species are not well identified so far. Methods The secondary metabolites of Terminalia bellirica and Terminalia sericea leaves were identified using HPLC-PDA-MS/MS. The antioxidant activities of the leaves extracts were determined by DPPH and FRAP assays. The hepatoprotective potential was evaluated in rats with D-galactosamine induced liver damage. The effect of the extracts on the expression of the anti-apoptotic marker Bcl-2 was measured in an immunohistochemical study. The most abundant compounds identified in the studied extracts were docked into Bcl-2: Bim (BH3) interaction surface using molecular operating environment software. Results A total of 85 secondary metabolites were identified in the leaf extracts of both species. Ellagitannins such as corilagin, chebulagic acid, galloylpunicalagin, and digalloyl-hexahydroxydiphenoyl-hexoside were found to be the major components in Terminalia bellirica whereas flavonoid glycosides including quercetin rutinoside and quercetin galloyl-glucoside were highly abundant in Terminalia sericea. The studied extracts exhibited pronounced antioxidant activities, moderate anti-apoptotic and hepatoprotective potential. In silico docking experiments revealed that the compounds abundant in the extracts were able to bind to Bcl-2: Bim (BH3) interaction surface with an appreciable binding free energy. Discussion The antioxidant and hepatoprotective activities exhibited by the studied extracts might be attributed to the high content of the polyphenols. The anti-apoptotic activity could be due to the interference with the apoptotic pathway mediated by Bcl-2: Bim interaction. These findings support the medicinal relevance of Terminalia bellirica and Terminalia sericea and provide a rational base for their utilization in folk medicine

    Whole genome mapping and identification of single nucleotide polymorphisms of four Bangladeshi individuals and their functional significance

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    Objective: The major objective of the study was to sequence the whole genome of four Bangladeshi individuals and identify variants that are known to be associated with functional changes or disease states. We also carried out an ontology analysis to identify the functions and pathways most likely to be afected by these variants. Results: We identifed around 900,000 common variants and close to 5 million unique ones in all four of the indi‑ viduals. This included over 11,500 variants that caused nonsynonymous changes in proteins. Heart function associ‑ ated pathways were heavily implicated by the ontology analysis; corroborating previous studies that claimed the Bangladeshi population as highly susceptible to heart disorders. Two variants were found that have been previously identifed as pathogenic factors in familial hypercholesteremia and structural disorders of the heart. Other pathogenic variants we found were associated with pseudoxanthoma elasticum, cancer progression, polyagglutinable erythro‑ cyte syndrome, preeclampsia, and other

    The global distribution and burden of dengue

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    Dengue is a systemic viral infection transmitted between humans by Aedes mosquitoes1. For some patients dengue is a life-threatening illness2. There are currently no licensed vaccines or specific therapeutics, and substantial vector control efforts have not stopped its rapid emergence and global spread3. The contemporary worldwide distribution of the risk of dengue virus infection4 and its public health burden are poorly known2,5. Here we undertake an exhaustive assembly of known records of dengue occurrence worldwide, and use a formal modelling framework to map the global distribution of dengue risk. We then pair the resulting risk map with detailed longitudinal information from dengue cohort studies and population surfaces to infer the public health burden of dengue in 2010. We predict dengue to be ubiquitous throughout the tropics, with local spatial variations in risk influenced strongly by rainfall, temperature and the degree of urbanisation. Using cartographic approaches, we estimate there to be 390 million (95 percent credible interval 284-528) dengue infections per year, of which 96 million (67-136) manifest apparently (any level of clinical or sub-clinical severity). This infection total is more than three times the dengue burden estimate of the World Health Organization2. Stratification of our estimates by country allows comparison with national dengue reporting, after taking into account the probability of an apparent infection being formally reported. The most notable differences are discussed. These new risk maps and infection estimates provide novel insights into the global, regional and national public health burden imposed by dengue. We anticipate that they will provide a starting point for a wider discussion about the global impact of this disease and will help guide improvements in disease control strategies using vaccine, drug and vector control methods and in their economic evaluation. [285
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