4,295 research outputs found

    Leukotrienes and leukotriene modifiers in pediatric allergic diseases

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    Leukotrienes are potent pro-inflammatory lipid mediators derived from arachidonic acid through several enzymatic pathways. They have an essential role in allergic inflammation, where they induce bronchoconstriction, airway edema, and chemotaxis of the inflammatory cells in the airways, nasal and conjunctival tissues. Leukotriene modifiers include leukotriene receptor antagonists (montelukast, zafirlukast and pranlukast) and leukotriene synthesis inhibitors (zileuton). These medications have been extensively used in childhood allergic diseases. This review will highlight the leukotriene pathway and its role in allergy as well as the effects of leukotriene modifiers in different allergic disorders

    The Effect of Pressure and Temperature on the Conductivity and Sensitivity of SnO2/Pt Based Gas Sensors

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    Phosphorylation and Promising In-Vitro Antimicrobial Activity of Some New Organosulfur Compounds

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    During the past few decades, interest has been rapidly growing in gaining insight into the properties and transformations of thiosemicarbazide and their derivatives due to their appreciable pharmacological activities. Dimethoxy acetophenone reacts with thiosemicarbazide to afford compound (1). The product allowed to react by fusion with diethylmalonate and ethylacetoacetate to give cyclic compounds (3), (4) and (7). Their products are reacted with triphenylphosphine oxide to produce phosphorylated compounds with four and six membered rings. Some of these products display interesting biological and antibacterial activities which lead to great interest for possible therapeutic uses. The structure of the products are confirmed by elemental analyses, IR, UV, 1H-NMR and MS specra.Â

    Novel synthesis, ring transformation and anticancer activity of 1,3-thiazine, pyrimidine and triazolo[1,5-a]pyrimidine derivatives

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    Synthesis, heterocyclization and anticancer activity of a new series of heterocyclic compounds are described. Aminothiazine 1 was obtained from the base induced condensation of thiourea, benzaldehyde and ethyl cyanoacetate. The synthesis of N-phenyl amino pyrimidine derivative 2 was obtained as a result of reaction of aniline with compound 1. Compound 2 underwent ring opening and recyclization upon reaction with HCl or H2O2/ NaOH to afford the acid derivative 3 or oxazine 4, respectively. Thiazine 1 undergoes ring transformation upon the effect of NH2OH.HCl to produce pyrimidine derivative 5. Heterocyclization of compound 1 with thiosemicarbazide followed by oxidation with I2/AcOH afforded triazolopyrimidine 6 and 7, respectively. Alkylation of compound 1 was promoted by reaction of 1 with ethyl iodide to give alkylated thiazine 8 which in turn undergo ring transformation when subjected to reaction with hydrazine hydrate to give pyrazole derivative 9. Refluxing of amino-1,3-thiazine derivative 1 with ethyl bromoacetate in the presence of Et3N produce the alkylated pyrimidine product 10. Hydrazonolysis of 1,3-thiazine 1 with hydrazine or phenyhydrazine gave pyrimidine derivatives 11a,b, respectively. Compound 11b was cyclized with carbon disulfide or formaldehyde to produce triazolopyrimidines 12 and 13, respectively. Some of the new compounds were screened for anticancer activity and significant results were found for some compounds.               KEY WORDS: 1,3-Thiazine, Pyrimidine, Triazole, Pyrazole, Anticancer activity Bull. Chem. Soc. Ethiop. 2018, 32(3), 513-522.DOI: https://dx.doi.org/10.4314/bcse.v32i3.1

    Development of chitosan-glucose and chitosan-citric complexes edible coating to improve tomatoes post-harvest quality

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     The effect of different shrimp chitosan molecular weights as well as shrimp chitosan complexes (chitosan-glucose and chitosan-citric) on the quality characteristics of the stored (at 7°C±2°C and 90% RH) tomato fruits (Lycopersicum esculentum) was investigated.  Coating tomatoes with high molecular weight chitosan (H.M.C.G) significantly improved firmness and weight loss.  The lowest weight loss was found in high molecular weight chitosan-glucose (H.M.C.G) treatment followed by the fruits coated with high molecular weight chitosan (HMC) and then uncoated tomato fruits.  Both molecular weights was clear on retarding the total acidity loss especially for stored tomato fruit coated with low molecular weight chitosan, while control tomatoes exhibited a larger reduction (p ≤ 0.05) in total acidity over storage.  Meanwhile, the increasing of cold storage time significantly (p ≥ 0.05) increased the pH in all uncoated and coated tomatoes.  Generally, no significant (P > 0.05) difference was observed in pH, titratable acidity and total soluble solids (T.S.S.) as well as sensory attributes among the tomato fruits coated with chitosan, chitosan citric and chitosan glucose.  Meanwhile, the fruits coated with low molecular weight chitosan had a higher (p ≥ 0.05) T.S.S. compared with that coated by the high molecular weight chitosan.   Keywords: chitosan, edible coating, tomatoes, firmness and weight loss

    Resistance of Alkali Activated Water-Cooled Slag Geopolymer to Sulphate Attack

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    Ground granulated blast furnace slag is a finely ground, rapidly chilled aluminosilicate melt material that is separated from molten iron in the blast furnace as a by-product. Rapid cooling results in an amorphous or a glassy phase known as GGBFS or water cooled slag (WCS). Alkaline activation of latent hydraulic WCS by sodium hydroxide and/or sodium silicate in different ratios was studied. Curing was performed under 100 % relative humidity and at a temperature of 38°C. The results showed that mixing of both sodium hydroxide and sodium silicate in ratio of 3:3 wt.,% is the optimum one giving better mechanical as well as microstructural characteristics as compared with cement mortar that has various cement content (cement : sand were 1:3 and 1:2). Durability of the water cooled slag in 5 % MgSO4 as revealed by better microstructure and high resistivity-clarifying that activation by 3:3 sodium hydroxide and sodium silicate, respectively is better than using 2 and 6 % of sodium hydroxide

    Medical students’ attitudes towards patient-centered care, Fayoum Medical School, Egypt

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    Background: Patient-centered care has been considered the foundation of healthcare quality and the core competency of the doctor-patient relationship.Aims: To assess the attitudes of medical students toward a patient-centered approach and identify the predictors of patient-centeredness scores.Methods: A cross-sectional study was carried out in Fayoum Medical School/Egypt using a validated Arabic version of the Patient-Practitioner Orientation Scale (PPOS).Results: The total PPOS score showed variable score as the grades move up. The total PPOS ranged from 0.05 to 4.39 with an average score of (2.71 ± 0.66) for the entire sample. The sharing and caring subscale score ranged from 0.56 to 4.44 and 0.44 to 5.33 with an average score of (2.33 ± 0.49) and (3.09 ± 0.92) respectively.Conclusion: Medical students had low patient-centered attitude. Medical curricula should be redesigned, and medical students may also benefit from engagement in patient healthcare service

    Impact Factors on Subcontractor's Cash Flow Management

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    Objective: This study aims to define how to maintain and protect the subcontractor firms' cash flow from economic fluctuation through legally sustainable solutions. Methods/Analysis: We conducted a case study in the Eastern Delta Region of Egypt. A questionnaire containing a list of 22 impact factors on subcontractors' cash flow was distributed across multiple subcontractor firms with an 82% response rate. It was designed to explore the factors causing cash flow instability and analyze them using SPSS statistics. Findings: The study finds that inflation, late payments, non-compensation for late payments, poor subcontractor cash flow management, subcontractor firms' inclination to avoid disputes, material price fluctuation, and non-compensation terms, as well as suppliers rejection of payment delays, are the most critical factors of subcontractor cash flow problems. Novelty/Improvement:The study suggests adding three sub-articles to Article 57 in "Tender Law" as legally sustainable solutions to protect and maintain the firm's growth rate from inflation, late payment, and the inclination to avoid disputes. Also, the study recommends that the owner ensure that cash is available before procuring the general contractors, as stated in Egyptian Law 182 of 2018. This study will contribute to establishing a sustainable win-win relationship between subcontractors and general contractors. Doi: 10.28991/CEJ-SP2023-09-08 Full Text: PD
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