Browsing by Author "Diab, A"

Now showing 1 - 4 of 4

Antibacterial and Anti-Fungal Biological Activities for Acrylonitrile, Acrylamide and 2-Acrylamido-2-Methylpropane Sulphonic Acid Crosslinked Terpolymers
(MDPI AG, 11/01/2020) Farag, R.K; Atta, A.M; Labena, A; Alhawari, S.H; Safwat, G; Diab, A
There is a pressing demand to synthesize polymers that have antibacterial and antifungal properties. The aim of this study was to synthesize a crosslinked hydrophilic terpolymer with acrylamide, acrylonitrile, acrylic acid, acrylamido-2-methylpropane sulphonic acid and ethylene glycol dimethacrylate as a crosslinker. The chemical structure and thermal stability of the prepared cross-linked terpolymers were confirmed by spectroscopic and thermal analyses. Moreover, the swelling experiments were performed to investigate their swelling capacity. Furthermore, the efficiency of the synthesized cross-linked polymer gels was assessed as an antimicrobial agent against Gram-positive, Gram-negative bacteria and fungal strains. The synthesized polymers showed broad inhibition effect, with more antibacterial activity by the AM4 polymer sample containing high percentage of acrylonitrile monomer in the prepared terpolymers (4 mol ratio of acrylic acid: 1 mol ratio of acrylamide: 16 mole ratio of acrylonitrile against Gram negative bacterial strain), while sample M3 terpolymer (1 mol ratio of acrylamide: 1 mole ratio acrylonitrile: 3 mole ratio of acrylamido-2-methylpropane sulphonic acid) showed a promising anti-fungal activity. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
BIOLOGY, CYTOPATHOLOGY AND MOLECULAR IDENTIFICATION OF AN EGYPTIAN ISOLATE OF zucchi YELLOW MOSAIC POTYVIRUS (zym-EG)
(Pak. J. Biotechnol. Vol, 2010) El-Hoseny, ME; El-Fallal A, Amira; El-Sayed, AK; Diab, A; Sadik, AS
Squash is considered as one of the most important crops in Egypt and worldwide. Zucchini yellow mosaic potyvirus (ZYMV) is considered as one of the most important viruses infects squash. We used the biological, serological and cytopathological studies to identify an Egyptian isolate of ZYMV. Results showed that the Egyptian isolate of ZYMV showed systemic symptoms in the form of severe mosaic and vein banding on Cucurbita pepo cv. Eskandarani under open field conditions. Direct antigen coated (DAC)-enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies was used as a diagnostic tool for detecting ZYMV in the virus-infected C. pepo samples. It showed positive reactions with ZYMV antiserum. Filamentous virus-like particles measuring 750X13 nm was successfully purified from ZYMV-infected squash plants, based on the use of polyethylene glycol and ultracentrifugation. The electron microscope of ultrathin sections of virus-infected leaf tissues revealed the presence of cylindrical inclusions as pinwheels, laminated aggregates and scrolls in the cytoplasm of cells infected with ZYMV. In addition, disorganization of plastids, nucleus and mitochondria in the virus-cells infected was also observed. In addition, the nucleotide of CI gene of the viral isolate under investigation was determined and its similarities to some overseas isolates were addressed
Perturbative instability of inflationary cosmology from quantum potentials
(INDIAN ASSOC CULTIVATION SCIENCE, 2017) Tawfik, A; Diab, A; Abou El Dahab, E
It was argued that the Raychaudhuri equation with a quantum correction term seems to avoid the Big Bang singularity and to characterize an everlasting Universe (Ali and Das in Phys Lett B 741:276, 2015). Critical comments on both conclusions and on the correctness of the key expressions of this work were discussed in literature (Lashin in Mod Phys Lett 31:1650044, 2016). In the present work, we have analyzed the perturbative (in) stability conditions in the inflationary era of the early Universe. We conclude that both unstable and stable modes are incompatible with the corresponding ones obtained in the standard FLRW Universe. We have shown that unstable modes do exist at small (an) isotropic perturbation and for different equations of state. Inequalities for both unstable and stable solutions with the standard FLRW space were derived. They reveal that in the FLRW flat Universe both perturbative instability and stability are likely. While negative stability modes have been obtained for radiation- and matter-dominated eras, merely, instability modes exist in case of a finite cosmological constant and also if the vacuum energy dominates the cosmic background geometry.
Production, Characterization and Application of a New Biosurfactant Derived from Egyptian Sunflower Seeds
(Int. J. of Agrci. Sci. and Res, 2016) Diab, A; Sami, Shereen; Diab, AA
A new biosurfactant (SR122) was obtained for the first time from the seeds of sunflower plant growing locally in Egypt. This bioproduct was recovered from the seeds using simple and cost effective method that gave higher biosurfactant yield (20-25% w/w). The new product (SR 122) may be an alternative to the microbial and synthetic surfactants because it is non toxic (as it was originated from safe natural sources- the plant), cost-effective, produced in higher yield (as compared to the microbial biosurfactant) and may acquire public acceptance. The high surface activity of SR 122 (as measured by the ODA method, surface tension reduction and E24 method), the non-toxicity and tolerance to wide range of harsh condition of temperatures (up to 121ºc), pH values (2-11) and different NaCl concentrations (2% -25% w/v) make this new product a promising candidate for the application in many industries and for the protection of the environment. On a large laboratory scale SR122 was applied for cleaning oil storage tank. During the cleaning process more than 95% of the oily sludge was recovered and the viscosity of the recovered oil was decreased allowing the oily sludge to be easily floated on the top of the biosurfactant as a distinct phase. This product SR 122 was offered for a patent no: 1289/2014