Publications by authors named "Ahmed K El-Sayed"

The utilization of manufactured lightweight aggregates adds another dimension to the cost of the preparation of self-compacting concrete (SCC). The common practice of adding absorption water to the lightweight aggregates before concreting leads to inaccurate calculations of the water-to-cement ratio. Moreover, the absorption of water weakens this interfacial bond between aggregates and the cementitious matrix.

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Intermediate crack (IC) debonding and concrete cover separation (CCS) are common types of debonding failures in concrete beams flexurally strengthened with fiber-reinforced polymer (FRP) composites. In this paper, a three-dimensional finite element (FE) model was developed to simulate the flexural behavior and predict the critical debonding failure in FRP-strengthened beams. The two critical debonding failures were considered in the FE model by implementing a cohesive zone model based on fracture mechanics considering the effect of the related parameters.

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Plate end (PE) debonding is one of the critical debonding failure modes that may occur in reinforced concrete (RC) beams strengthened with externally bonded fiber reinforced polymers (FRPs). This study investigated the effect of internal steel stirrups on the PE debonding failure load of FRP-strengthened RC beams. The dimensions of the beams were 3400 × 400 × 200 mm.

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A novel biosynthesis of dual reduced graphene oxide/silver nanocomposites (rGO/AgNC) using the crude metabolite of Escherichia coli D8 (MF06257) strain and sunlight is introduced in this work. Physicochemical analysis of these rGO/AgNC revealed that they are sheet-like structures having spherically shaped silver nanoparticles (AgNPs) with an average particle size of 8 to 17 nm, and their absorption peak ranged from 350 to 450 nm. The biosynthesized rGO/AgNC were characterized by UV-vis and FT-IR spectra, X-ray diffraction, Zeta potential and transmission electron microscopy.

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Article Synopsis
  • Ergosterol peroxide and ganoderic acid AMI were isolated for the first time from the mycelium of the Egyptian Ganoderma resinaceum mushroom, with their structures determined through detailed NMR analysis.
  • The compounds were tested for their antitumor activities on breast cancer cell lines, specifically MCF-7 and MDA-MB-231.
  • Ergosterol peroxide exhibited stronger inhibition against the estrogen receptor-positive MCF-7 cells (IC50 of 1.18 μM) compared to the estrogen receptor-negative MDA-MB-231 cells (IC50 of 12.82 μM), indicating a potential targeting of estrogen receptors by this compound.*
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Air sacs are considered to be one of the controlling factors of bird behaviour and habits in addition to their roles in ventilation, regulating body temperature, swimming and flight. As a scavenger and an omnivorous flight bird, air sacs of the hooded crow were the focus of this study. Eight healthy, adult hooded crows were used to examine the morphological characteristics of the air sacs, which were examined grossly and with latex and cast preparations.

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The use of bone marrow mesenchymal stem cells (BMSCs) has great potential in cell therapy, particularly in the orthopedic field. BMSCs represent a valuable renewable cell source that have been successfully utilized to treat damaged skeletal tissue and bone defects. BMSCs can be induced to differentiate into osteogenic lineages via the addition of inducers to the growth medium.

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Large bone defects and bone loss after fractures remain significant challenges for orthopedic surgeons. Our study aims to find an available, applicable and biological treatment for bone regeneration overcoming the limitations in ESC/iPSC technology. We directly reprogrammed the mouse embryonic fibroblast (MEF) into osteoblast cells using different combinations of Yamanaka factors with human lim mineralization protein-3 (hLMP-3).

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Aim: The growth promoting effect of the blue-green filamentous alga (SP) was observed on meat type Japanese quail with antibiotic growth promoter alternative and immune enhancing power.

Materials And Methods: This study was conducted on 180 Japanese quail chicks for 4 weeks to find out the effect of diet type (vegetarian protein diet [VPD] and fish meal protein diet [FMPD])- Spirulina dose interaction (1 or 2 g/kg diet) on growth performance, gut microbiota, and sensory meat quality of growing Japanese quails (1-5 weeks old).

Results: Data revealed improvement (p<0.

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Reprogramming of somatic cells has great potential to provide therapeutic treatments for a number of diseases as well as provide insight into mechanisms underlying early embryonic development. Improvement of induced Pluripotent Stem Cells (iPSCs) generation through mRNA-based methods is currently an area of intense research. This approach provides a number of advantages over previously used methods such as DNA integration and insertional mutagenesis.

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α-Amylase from Thermoactinomyces vulgaris was highly purified 48.9-fold by ammonium sulfate precipitation, gel filtration on Sephadex G-50 column, and ion exchange chromatography column of DEAE-cellulose. The molecular weight of the enzyme was estimated to be 135 and 145 kDa by SDS-PAGE.

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