King Abdullaziz University

Jeddah, Saudi Arabia

King Abdullaziz University

Jeddah, Saudi Arabia
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Hindi S.S.Z.,King Abdullaziz University | Abohassan R.A.,King Abdullaziz University
BioResources | Year: 2015

Cellulosic fibers from cotton fibers (CF), recycled writing papers (RWP), recycled newspapers (RN), and macerated woody fibers of Leucaena leucocephala (MWFL) were acetylated by heterogeneous reactions with glacial acetic acid, concentrated H2SO4, and acetic anhydride. The resultant cellulose triacetate (CTA) was characterized for yield and solubility as well as by using 1H-NMR spectroscopy and SEM. The acetylated product (AP) yields for CF, RWP, RN, and MWFL were 112, 94, 84, and 73%, respectively. After isolation of pure CTA from the AP, the CTA yields were 87, 80, 68, and 54%. The solubility test for the CTA's showed a clear solubility in chloroform, as well as mixture of chloroform and methanol (9:1v/v) and vice versa for acetone. The degree of substitution (DS) values for the CTA's produced were nearly identical and confirmed the presence of CTA. In addition, the pore diameter of the CTA skeleton ranged from 0.072 to 0.239 μm for RWP and RN, and within the dimension scale of the CTA pinholes confirm the synthesis of CTA. Accordingly, pouring of the AP liquor at 25 °C in distilled water at the end of the acetylation and filtration did not hydrolyze the CTA to cellulose diacetate.

Seyedmousavi S.,Erasmus University Rotterdam | Seyedmousavi S.,Radboud University Nijmegen | Seyedmousavi S.,Mazandaran University of Medical Sciences | Guillot J.,National Veterinary School of Alfort | And 7 more authors.
Clinical Microbiology and Infection | Year: 2015

Zoonotic fungi can be naturally transmitted between animals and humans, and in some cases cause significant public health problems. A number of mycoses associated with zoonotic transmission are among the group of the most common fungal diseases, worldwide. It is, however, notable that some fungal diseases with zoonotic potential have lacked adequate attention in international public health efforts, leading to insufficient attention on their preventive strategies. This review aims to highlight some mycoses whose zoonotic potential received less attention, including infections caused by Talaromyces (Penicillium) marneffei, Lacazia loboi, Emmonsia spp., Basidiobolus ranarum, Conidiobolus spp. and Paracoccidioides brasiliensis. © 2015 European Society of Clinical Microbiology and Infectious Diseases.

Seyedmousavi S.,Radboudumc | Seyedmousavi S.,Erasmus University Rotterdam | Seyedmousavi S.,Mazandaran University of Medical Sciences | Netea M.G.,Radboudumc | And 9 more authors.
Clinical Microbiology Reviews | Year: 2014

Among the melanized fungi, the so-called "black yeasts" and their filamentous relatives are particularly significant as agents of severe phaeohyphomycosis, chromoblastomycosis, and mycetoma in humans and animals. The pathogenicity and virulence of these fungi may differ significantly between closely related species. The factors which probably are of significance for pathogenicity include the presence of melanin and carotene, formation of thick cell walls and meristematic growth, presence of yeast-like phases, thermo- and perhaps also osmotolerance, adhesion, hydrophobicity, assimilation of aromatic hydrocarbons, and production of siderophores. Host defense has been shown to rely mainly on the ingestion and elimination of fungal cells by cells of the innate immune system, especially neutrophils and macrophages. However, there is increasing evidence supporting a role of T-cell-mediated immune responses, with increased interleukin-10 (IL-10) and low levels of gamma interferon (IFN-γ) being deleterious during the infection. There are no standardized therapies for treatment. It is therefore important to obtain in vitro susceptibilities of individual patients' fungal isolates in order to provide useful information for selection of appropriate treatment protocols. This article discusses the pathogenesis and host defense factors for these fungi and their severity, chronicity, and subsequent impact on treatment and prevention of diseases in human or animal hosts. © 2014, American Society for Microbiology. All Rights Reserved.

Al-bishri H.M.,King Abdullaziz University | Abdel-Fattah T.M.,Jefferson Lab | Abdel-Fattah T.M.,Christopher Newport University | Mahmoud M.E.,Alexandria University
Journal of Industrial and Engineering Chemistry | Year: 2012

A method is described for highly efficient adsorptive removal of lead with a maximum metal capacity value of 1.300mmolg -1 by using physically immobilized [Bmim +Tf 2N -] on the surface of nano-silica-amine sorbent. Lead sorption was found to be highly dependent and controlled by several experimental factors. The effect of sorbent dose played a significant role by yielding the maximum lead adsorption capacity when 100mg sorbent was used. The effect of lead concentration was examined by various adsorption isotherms. The potential applications for removal of Pb(II) were studied and the percentage recovery values were 99.0-100.0±2.0-5.0%. © 2012 The Korean Society of Industrial and Engineering Chemistry.

Nafee S.S.,Alexandria University | Nafee S.S.,King Abdullaziz University
Nuclear Technology | Year: 2010

The calibration of gamma-ray cylindrical detectors is often required in the analysis of high or low environmental samples and the homogenously distributive nuclear waste drums. Therefore, a new analytical simulation method is proposed in the present work to calculate the full-energy peak efficiencies of high-purity germanium cylindrical detectors using extended sources of low and high volumes. The sources were mounted at three different positions with respect to the detector's axis (coaxial, parallel, and perpendicular), labeled as Position 1, Position 2, and Position 3, respectively. The self-attenuation and the coincidence summing effects at low sourcedetector distance are also included in the algorithm. A remarkable agreement between the measured and the calculated efficiencies is achieved with discrepancies <4% for the first two positions and between 5 and 7% for the last one.

Mahmoud M.E.,Alexandria University | Al-bishri H.M.,King Abdullaziz University
Separation Science and Technology (Philadelphia) | Year: 2013

A method is described for the selective separation and extraction of cadmium-lead from aqueous solutions by tuning the pH value between 1.0 and 7.0. A modified nano-active silica sorbent was loaded with 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide hydrophobic ionic liquid, [Bmim+Tf2N-] and used in this work. The pH value was found to play a significant role in the sorption capacity of Cd(II) and Pb(II). In pH 1.0, the metal capacity values were characterized as 1.40 and 0.30 mmol g-1 for Cd(II) and Pb(II), respectively. In pH 7.0, Cd(II) and Pb(II) switched their capacity values to 0.65 and 1.00 mmol g-1, respectively. An anion exchange mechanism was proposed in solution with pH 1.0 for exchange of chloroanionic cadmium species by [Tf2N-]. The sorptive separation processes of Cd(II) and Pb(II) were studied and evaluated under the influence of various controlling factors. The potential applications of modified nano-silica sorbent for selective sorptive removal and separation of Cd(II) from Pb(II) in water samples was successfully accomplished by adjusting the pH value of the contact solution between 1.0 and 7.0. The results of this study indicated an efficient extraction behavior of the two examined metal ions. © 2013 Copyright Taylor and Francis Group, LLC.

Kowalski D.,Friedrich - Alexander - University, Erlangen - Nuremberg | Kim D.,Korea Electrotechnology Research Institute | Schmuki P.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schmuki P.,King Abdullaziz University
Nano Today | Year: 2013

Anodization of valve metals and alloys is a powerful tool to control nanoscale architecture for many metal oxides. Except for aluminum, the most explored system is self-organized oxide formed on titanium, namely self-organized TiO2 nanotubes, because of the unique combination of geometry with the semiconductive nature of titania that is applicable in photocatalysis, light harvesting systems, electrochromic devices, batteries, matrices, templates, filtration membranes, and bio-compatible materials. In this contribution, we review recent advances in the formation of nanostructured oxides in the form of nanotubes, nanopores with a through-hole morphology, mesosponges, nanochannels and microcones grown on Ti, Nb, Ta, Zr, Hf, W, V and their alloys. We discuss mechanisms of their formation, key functional features, and describe their applications in various fields of chemistry and electrochemistry.

Nafee S.,Alexandria University | Nafee S.,King Abdullaziz University
Applied Radiation and Isotopes | Year: 2011

Marinelli beakers increase geometric efficiency of detection in the γ-spectrometry of low-activity environmental samples by positioning the sample in close proximity to the detector. A probability correction has been introduced to the analytical simulation approach proposed previously (Nafee et al., 2009) for calculating detection efficiencies of γ-ray cylindrical detectors using extended low- and high-volume Marinelli beakers. Improved expressions for the self-attenuation and the coincidence summing effects at short source-detector distances have also been included in the analytical algorithm. A remarkable agreement between the measured and calculated efficiencies was observed as a result. Deviations of results calculated in this way from experimental values are twice as small as were observed with the previously reported analytical methods (Abbas, 2001; Nafee et al., 2009). © 2011 Elsevier Ltd.

Gheith A.M.,Mansoura University | Hariri M.S.,King Abdullaziz University
Journal of King Abdulaziz University, Marine Science | Year: 2010

Our investigations focus on the significance of texture, fauna, minerals and chemical characteristics of bottom sediments of Sharm Obhur. The back reef zones were subjected to filling, dredging and cutting processes for constructional and urbanization purposes. Shores morphology and sediment properties are changed. The geological study emphasized the nature, composition and chemical characteristics of sediment veneer in addition to the impact of human activity on the environmentally sensitive area like Sharm Obhur. Sediments are believed to be the last sink for contaminants that reach the sea. It is therefore, sedimentary regime to investigate and understand the depositional pattern of sediments. The study proved that Sharm Obhur bottom environment and its shores suffered deterioration due to uncontrolled development. Heavy metals; Zn, Cu, Ni, Cd beside minor elements; Fe and Mn have been increased in bottom sediments most probably due to human activities. The fine sediments are favourable site for the fixation of organic matter and trace elements.

Seifeldin S.A.,King Saud University | Seifeldin S.A.,Cairo University | Shawky M.,King Abdullaziz University | Hicham Nouman S.M.,Cairo University
Journal of Craniofacial Surgery | Year: 2014

PURPOSE: The aim of this study was to evaluate soft tissue response after chin advancement using 2 different genioplasty techniques. METHODS: The study included 8 adult patients who were divided equally into 2 groups: group 1 was surgically treated by sliding genioplasty, and group 2 was surgically treated by chin shield genioplasty for the correction of retruded or deficient chin. Lateral cephalograms were taken twice: immediately preoperative and 6 months postoperative. RESULTS: The mean (SD) change of soft tissue pogonion (Pg') was 4.7 (0.3) mm in group 1, whereas in group 2, the mean (SD) change of soft tissue pogonion (Pg') was 6.2 (4.8) mm. The mean (SD) change in the labiomental depth in group 1 was 0.9 (0.3) mm, whereas in group 2, it was 0.2 (0.5) mm. So in group 2, chin shield genioplasty contributed to a less labiomental fold depth. The ratio of soft tissue response to bony movement in the sliding genioplasty technique was 1:0.83, whereas in the chin shield genioplasty technique, it was 1:0.99. CONCLUSIONS: In the chin shield genioplasty technique, the increase in labiomental fold depth was less than in the sliding genioplasty technique. © 2014 Mutaz B. Habal, MD.

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