Browsing by Author "Tawfik, A"

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Narrow band ultraviolet B therapy deactivates Th1/Th17 pathway and activates Th2 cytokines secretion in Egyptian psoriatic arthritis patients
(TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND, 01/01/2020) Farid, A; Tawfik, A; Elsioufy, B; Safwat, G
Psoriasis is a chronic autoimmune disorder that affects 3-4% of the world population. Keratinocytes and immune cells in patient's skin secrets excess pro-inflammatory cytokines that in turn activates the differentiation of T helper cells (Th) into Th1 and Th17 and deactivates Th2 pathway. Several phototherapies have been used in treatment of moderate and severe psoriatic patients; among them narrowband ultraviolet B (NB-UVB, 311 nm) is the most effective. We aims to evaluate the therapeutic effect of NB-UVB exposure in 80 Egyptian plaque psoriatic patients with and without psoriasis arthritis development. This will be accomplished by measuring serum cytokines levels (IL-10, -12, -17, -23 and -34) and high sensitive C reactive protein before and after treatment. A significant elevation in Th2 pathway cytokine, IL-10, and significant decrease in Th1/Th17 pathway cytokines were observed after treatment. This indicates the success of NB-UVB therapy in down modulating IL-12 and IL-23/Th17 axis. The pathological conditions in psoriatic arthritis patients were improved by NB-UVB targeted to the skin. As serum cytokines levels in these patients indicated that the reduction in Th1/Th17 inflammatory cytokines and elevation of Th2 anti-inflammatory cytokines was not restricted to skin lesions only, but also, spread in patients' body and improve their pathologic
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.
Possible interrelations among chemical freeze-out conditions
(WORLD SCIENTIFIC PUBL CO PTE LTD, 2016-03) Abbas, E; Mohamed, M. T; Habashy, D. M; El-Bakry, M. Y; Tawfik, A
At thermal equilibrium, different chemical freeze-out conditions have been proposed so far. They have an ultimate aim of proposing a universal description for the chemical freeze-out parameters (T-ch and mu(b)), which are to be extracted from the statistical fitting of different particle ratios measured at various collision energies with calculations from thermal models. A systematic comparison between these conditions is presented. The physical meaning of each of them and their sensitivity to the hadron mass cuts are discussed. Based on availability, some of them are compared with recent lattice calculations. We found that most of these conditions are thermodynamically equivalent, especially at small baryon chemical potential. We propose that further crucial consistency tests should be performed at low energies. The fireball thermodynamics is another way of guessing conditions describing the chemical freeze-out parameters extracted from high-energy experiments. We endorse the possibility that the various chemical freeze-out conditions should be interpreted as different aspects of one universal condition.
Thermal Description of Particle Production in Au-Au Collisions at RHIC Energies (STAR)
(PLEIADES PUBLISHING INC, 2015-07) Abbas, E; Tawfik, A
The hadron ratios measured in central Au-Au collisions are analysed by means of Hadron Resonance Gas (HRG) model over a wide range of nucleon-nucleon center-of-mass energies, root S-NN = 7.7-200 GeV as offered by the RHIC Beam Energy Scan I (BES-I) (STAR Collaboration). The temperature and baryon chemical potential are deduced from fits of experimental ratios to thermal model calculations assuming chemical equilibrium. We find that the resulting freeze-out parameters using single hard-core value and point-like constituents of HRG are identical. This implies that the excluded-volume comes up with no effect on the extracted parameters. We compare the results with other studies and with the lattice QCD calculations. Various freeze-out conditions are confronted with the resulting data set. The effect of including new resonances is also analysed. At vanishing chemical potential, a limiting temperature was estimated, T-lim = 158.5 +/- 3 MeV.