280 research outputs found

    Hadronic modes in the quark plasma with an internal symmetry

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    We show that requiring the quark partition function to be color singlet of SU(3) color gauge group leads to reordering the thermodynamic potential in terms of the colorless multi-quark modes (qqˉ,qqq,qˉqˉqˉ,...q{\bar q}, qqq, {\bar q}{\bar q}{\bar q}, ...) at any given temperature. In accord with the "preconfinement" property of QCD, under a suitable confining mechanism, these could evolve into color singlet hadrons/baryons at low temperatures. At fairly high temperatures these multi-quark color singlet structures propagate in the plasma like hadronic modes, just as in the more familiar low temperature phase. This suggests that there exists a strong correlation in the plasma at all temperatures which is in conformity with lattice results.Comment: 4 pages, no figures, two additional authors, little modification in the text and replaced version will appear in Euro. Phys. Jour.

    Surface Tension at Finite Tempearture in the MIT Bag Model

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    At T=0 T = 0 the surface tension σ1/3 \sigma ^{1/3} in the MIT bag model for a single hadron is known to be negligible as compared to the bag pressure B1/4 B^{1/4}. We show that at finite temperature it has a substantial value of 50 - 70 MeV which also differ from hadron to hadron. We also find that the dynamics of the Quark-Gluon Plasma is such that the creation of hybrids (ssˉg)(s\bar{s}g) with massive quarks will predominate over the creation of (ssˉ) (s\bar{s}) mesons.Comment: Substantial changes in the revised version and a new author included, 13 pages in Latex and one figur

    Hexavalent Chromium Removal and Reduction to Cr (III) by Polystyrene Tris(2-aminoethyl)amine

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    A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) concentration on adsorption was studied. The optimum pH for the removal of Cr (VI) was at pH 5, while optimum contact time and adsorbent dosage were 120 minutes and 10 g/L, respectively. Total chromium and Cr (VI) concentrations were analyzed by ICP-MS and UVVisible. Adsorption isotherms using Langmuir and Freundlich isotherm models revealed that the data fitted Langmuir isotherm model better than Freundlich with a maximum adsorption capacity of 312.27 mg/g. FTIR spectroscopy, Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) analyses were performed on the adsorbent before and after binding Cr (VI). All analyses confirmed the complexation of Cr (VI) to the adsorbent. Desorption experiments using KCl solution indicated 89.3% release of chromium, rendering this method of high potential for adsorbent regeneration.We wish to thank Professor Dr. Z. Abdeen for his valuable financial support which made this work possible. We also wish to thank the Aquatic and Aquaculture Research Laboratory at Al-Quds University for performing the ICP-MS analysis

    Kimia Dasar I

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    Contrast media volume is significantly related to patient lung volume during CT pulmonary angiography when employing a patient-specific contrast protocol

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    Aim: The purpose of this study is to investigate the relationship between contrast media volume and patient lung volume when employing a patient-specific contrast media formula during pulmonary computed tomography angiography (CTA). Materials and methods: IRB approved this retrospective study. CTA of the pulmonary arteries was performed on 200 patients with suspected pulmonary embolism (PE). The contrast media volume (CMV) was calculted by employing a patient-specific contrast formula. Lung volume was quantified employing semi-automated lung software that calculated lung volumes (intellispace -Philips). The mean cross-sectional opacification profile of central and peripheral pulmonary arteries and veins were measured for each patient and arteriovenous contrast ratio (AVCR) calculated for each lung segment.  Mean body mass index (BMI) and lung volume were quantified. Receiver operating (ROC) and visual grading characteristics (VGC) measured reader confidence in emboli detection and image quality respectively. Inter and intra-observer variations were investigated employing Cohen’s kappa methodology. Results: Results showed that the mean pulmonary arterial opacification of the main pulmonary circulation (343.88±73HU), right lung; upper (316.51±23HU), middle (312.5±39HU) and lower (315.23±65HU) lobes and left; upper (318.76±83HU), and lower (321.91±12HU) lobes. The mean venous opacification of all pulmonary veins was below 182±72HU. AVCR was observed at all anatomic locations (p<0.0002) where this ratio was calculated. Moreover, larger volumes of contrast significantly correlated with larger lung volumes (r=0.89, p<0.03) and radiation dose (p<0.03). VGC and ROC analysis demonstrated increased area under the curve: 0.831 and 0.99 respectively (p<0.02). Inter-observer variation was observed as excellent (κ = 0.71). Conclusion: We conclude that increased CMV is significantly correlated to increased patient lung volume and radiation dose when employing a patient-specific contrast formula. The effects patient habitus is highlighted

    Protein sociology of ProA, Mip and other secreted virulence factors at the Legionella pneumophila surface

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    The pathogenicity of L. pneumophila, the causative agent of Legionnaires’ disease, depends on an arsenal of interacting proteins. Here we describe how surface-associated and secreted virulence factors of this pathogen interact with each other or target extra- and intracellular host proteins resulting in host cell manipulation and tissue colonization. Since progress of computational methods like AlphaFold, molecular dynamics simulation, and docking allows to predict, analyze and evaluate experimental proteomic and interactomic data, we describe how the combination of these approaches generated new insights into the multifaceted “protein sociology” of the zinc metalloprotease ProA and the peptidyl-prolyl cis/trans isomerase Mip (macrophage infectivity potentiator). Both virulence factors of L. pneumophila interact with numerous proteins including bacterial flagellin (FlaA) and host collagen, and play important roles in virulence regulation, host tissue degradation and immune evasion. The recent progress in protein-ligand analyses of virulence factors suggests that machine learning will also have a beneficial impact in early stages of drug discovery

    Clinical Significance of G6PD Variants among Palestinians

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    Conclusion: We conclude that children with G6PD A-deficiency are also susceptible to AHA, but demonstrate in direct comparison within this same population that G6PD Mediterranean and G6PD Cairo are more severe forms of deficiency than G6PD A‐. Further, we show that the heretofore poorly studied G6PD Cairo may be associated with low‐level, chronic hemolysis. This study illustrates favism is a significant public health problem in Gaza due to fava beans as a staple in the diet and the coexistence of polymorphic G6PD deficiency variants in the society. Favism is an easily preventable and manageable genetic disorder with the proper awareness, intervention and education programs

    UV-Vis spectral evaluation of CR-39 detector exposed with diagnostic dosage

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    The effects of the X-ray irradiation and chemical etching on the physical and optical properties of CR-39 plastic detectors were investigated for different doses of X-ray. CR-39 detectors were etched in the solution of the 3 M of NaOH after irradiation for revelations of the track. The tracks formed on CR-39 either by irradiated X-ray or due to the effect of environment. The changes in the thickness after exposed have significant decrease in 60 kVp and started to increase in range of 70 kVp up to 100 kVp due to the formation of oxidation layer on surface by free radicals. The optical band gaps before etching and after etching were determined by using Ultraviolet-visible (UV-Vis) spectroscopy. The optical band gap is attributed to the indirect transition due to its amorphous nature which is significantly decline trend energy in increase of the energy fluence of radiation. The Urbach’s energy, is defined as the width of the tail localized states in the forbidden band gap which change increment trend as increase in dose delivered due to the distortion structure of the CR-39 in terms of the electron charges in valences electron hence attributes to the induced modification of angle bond between the neighboring atoms
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