79 research outputs found

    MHD Flow of a Micropolar Fluid past a Stretched Permeable Surface with Heat Generation or Absorption

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    This work considers steady, laminar, MHD flow of a micropolar fluid past a stretched semi-infinite, vertical and permeable surface in the presence of temperature dependent heat generation or absorption, magnetic field and thermal radiation effects. A set of similarity parameters is employed to convert the governing partial differential equations into ordinary differential equations. The obtained self-similar equations are solved numerically by an efficient implicit, iterative, finite-difference method. The obtained results are checked against previously published work for special cases of the problem in order to access the accuarcy of the numerical method and found to be in excellent agreement. A parametric study illustrating the influence of the various physical parameters on the skin friction coefficient, microrotaion coefficient or wall couple stress as well as the wall heat transfer coefficient or Nusselt number is conducted. The obtained results are presented graphically and in tabular form and the physical aspects of the problem are discussed

    Evaluation of the Antimicrobial Activity of Four Plant Essential Oils against Some Food and Phytopathogens Isolated from Processed Meat Products in Egypt

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    Synthetic preservatives are widely utilized by the food industry to inhibit the microbial contamination and increase food safety and shelf life. The excessive utilization of synthetic preservatives can have a negative impact on human health and the environment. There is a great interest to find out natural substances as possible food-preservatives. The consumers' preference for food products with natural ingredients prompted food manufacturers to utilize natural-based preservatives in their production. It is worth noting that plant essential oils (EOs) among the natural-based substances have been efficiently used as antimicrobial agents against phyto- and food pathogens. The current study was conducted to evaluate the microbial contamination of three industrial meat products from five governorates in Egypt, identify the predominant bacterial and fungal isolates and determine the antimicrobial efficacy of some EOs (thyme, fennel, anise and marjoram) against the most predominant microbial isolates. A sensory test was also performed to estimate the customer preferences for specific organoleptic aspects of meat products after EOs treatment. Results showed that there is a promising antimicrobial activity of all studied EOs against some microbial isolates in a dose-dependent manner. In particular, thyme EO showed the highest significant antibacterial activity against P. fluorescence and E. coli. Whereas the marjoram EO showed the highest activity against P. aeruginosa. In addition, the sensory test revealed that the treatment with anise and marjoram EOs showed the highest acceptability by the testers and did not show significant differences on the organoleptic properties with respect to control. As overall, the obtained results of the current research are promising and proved feasibility of employing plant EOs as possible preservatives for processed meat products

    Synthesis and antitumor testing of certain new fused triazolopyrimidine and triazoloquinazoline derivatives

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    AbstractNew series of 1,2,4-triazolopyrimidine and 1,2,4-triazoloquinazoline derivatives were designed, synthesized, and evaluated for their antitumor activity. Compounds 6, 11, 26, 29, 41, 44, 48, 49 and 58 were tested as antitumor agents by the use of DNA-binding assay on TLC-plates, colorimetric assay for the degree of DNA-binding (Methyl green-DNA displacement assay), evaluation of antineoplastic activity against Ehrlich Ascites Carcinoma in mice, and finally modulation of apoptosis. 5-Flurouracil, vitamin C and ethidium bromide were used as positive controls in these techniques. Compound 26 proved to be the most active member of these series as antitumor agent with IC50 value of 47±1. Several characteristic features were observed to be essential for activity such as the morpholine group and the phenylazo group, in addition the electron-withdrawing groups favor the activity than the electron-donating ones

    Molecular Characterization of Escherichia coli O157:H7 and non-O157 Shiga Toxin Producing E. coli from Retail Meat and Humans

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    A total of 550 meat samples (300 minced beef and 250 chicken meat) marketed in Zagazig City, Sharkia Governorate, Egypt, as well as 150 human stool samples were examined for Shiga toxin producing E. coli. Results revealed that the isolation rates of E. coli O157:H7 versus non- O157 were 1.7% versus 2.3% in minced beef, 0.8% versus 2% in chicken meat and 0.7% versus 2.7% in human stools. Other identified serotypes were including O111:H8 (25%), O26:H11 (20.8%), O55:H7 (16.7%) and O113:H21 (4.2%). Virulence associated genes were identified in E. coli serotypes, stx1 and stx2 were characterized in 16.7% and 62.5% of the isolates, while, eaeA and hlyA genes were identified in 50% and 70.8% of the examined serotypes, respectively. Genotyping of E. coli O157:H7 serotype from different sources using Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) fingerprinting revealed heterogenicity of the isolates, however, human and minced beef isolates were grouped in the same cluster indicating potential transmission of infection from contaminated beef to human consumers. In conclusion, ERIC-PCR is a highly discriminatory, reliable and cost-effective tool for tracing sources of infection with bacteria. Public health education and application of strict hygienic measures during slaughtering, transportation and preparation of meat are essential to minimize the risk of contamination and transmission of infection to consumer

    Osjetljiva spektrofotometrijska metoda za određivanje antagonista H2-receptora uz uporabu N-bromsukcinimida i p-aminofenola

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    A simple, accurate and sensitive spectrophotometric method for determination of H2-receptor antagonists: cimetidine (CIM), famotidine (FAM), nizatidine (NIZ), and ranitidine hydrochloride (RAN) has been full developed and validated The method was based on the reaction of these drugs with NBS and subsequent measurement of the excess N-bromosuccinimide by its reaction with p-aminophenol to give a violet colored product (max at 552 nm). Decrease in the absorption intensity (A) of the colored product, due to the presence of the drug, was correlated with its concentration in the sample solution. Different variables affecting the reaction were carefully studied and optimized. Under optimal conditions, linear relationships with good correlation coefficients (0.9988-0.9998) were found between A values and the corresponding concentrations of the drugs in a concentration range of 830, 622, 625, and 420 g mL1 for CIM, FAM, NIZ, and RAN, respectively. Limits of detection were 1.22, 1.01, 1.08, and 0.74 g mL1 for CIM, FAM, NIZ, and RAN, respectively. The method was validated in terms of accuracy, precision, ruggedness, and robustness; the results were satisfactory. The proposed method was successfully applied to the analysis of the above mentioned drugs in bulk substance and in pharmaceutical dosage forms; percent recoveries ranged from 98.5 0.9 to 102.4 0.8% without interference from the common excipients. The results obtained by the proposed method were comparable with those obtained by the official methods.Razvijena je i validirana ispravna, jednostavna i osjetljiva spektrofotometrijska metoda za određivanje antagonista H2-receptora: cimetidina (CIM), famotidina (FAM), nizatidina (NIZ) i ranitidin hidroklorida (RAN). Metoda se temelji na reakciji tih ljekovitih tvari s N-bromsukcinimidom (NBS). Višak N-bromsukcinimida određuje se nakon reakcije s p-aminofenolom s kojim daje ljubičasti produkt (max pri 552 nm). Smanjenje apsorpcijskog intenziteta (A) obojenog produkta, zbog prisutnosti ljekovite tvari korelirano je s njegovom koncentracijom u otopini uzorka. Proučavane su različite varijable koje utječu na reakciju. Linearno koncentracijsko područje za CIM, FAM, NIZ i RAN, s koeficijentom korelacije od 0,9988 do 0,9998, iznosi 830, 622, 625 odnosno 420 g mL1. Granice detekcije bile su 1,23, 1,02, 1,09 i 0,75 g mL1 za CIM, FAM, NIZ, odnosno RAN. Predložena metoda je uspješno primijenjena za analizu navedenih ljekovitih tvari i ljekovitih pripravaka. Nepreciznost od 0,7 do 1,2% i visoka ispravnost (analitički povrat između 98,5 i 102,4%), bez interferencije uobičajenih pomoćnih tvari, ukazuju na dobru analitičku metodu. Rezultati dobiveni predloženom metodom usporedivi su s rezultatima dobivenim službenom metodom

    Detection of SNPs in growth hormone and insulin like growth factor -1 genes in two divergently selected lines of Japanese quail

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    The Japanese quail (Coturnix japonica) is used for producing both meat and egg in many countries and as a model for animal research purposes. Two lines of Japanese quail that were differentiated by high body weight (HBW) and low body weight (LBW) had been improved by selection for body weight at four weeks of age. The objective of this study was to detect single nucleotide polymorphism (SNP) in Growth hormone (GH) and Insulin like Growth Factor -1 (IGF-1) genes in the two Japanese quails selected lines which based on the weight of the body at four weeks of age. DNA has been extracted from fifty blood samples by commercial kits and amplified by polymerase chain reaction (PCR). DNA sequencing revealed nucleotide polymorphisms between the two Japanese quails selected lines. The results of this investigation revealed that, one nucleotide change (T/C) in the intron 2 of GH gene. However, there were no nucleotide differences in IGF-1gene between the two selected lines. It concluded that, the SNP discovered in the GH gene may provide appropriate markers for associating researches of candidate genes with imperative economic measurements in Japanese quail. However, further studies are necessitating detecting mutation in another region of IGF-1
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