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Some Recently Published Papers عصام رشدى الزهار

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A DESCRIPTIVE ACCOUNT OF THE PHONOLOGY AND MORPHOLOGY OF NAJDI ARABIC ناصر محمد العجمي

This research aims to describe the phonology (sounds and their patterns) and morphology (word formation) of the current Najdi Arabic spoken in Najd Province.

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Iron ochre – a pre-catalyst for the cracking of methane عبدالرحمن ابراهيم الحارثي

Abdulrahman Alharthi, Ross A. Blackley, T. Hugh Flowers, Justin S. J. Hargreaves, Ian D. Pulford, James Wigzell and Wuzong Zhou, Iron ochre – a pre-catalyst for the cracking of methane, Journal of Chemical Technology & Biotechnology, 89 (2014) 1317-1323.

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التأثيرات الصحية للكهربية الساكنة في المحيط الحيوي بمدينة السليل بالسعودية اسماء محمد البشير سعد محمد سعد

 التقنية التي تستخدم كل يوم أنواع مختلفة من الأجهزة، مثل الهواتف المحمولة وحتى السيارات، وتنتج الحقل الكهربائي (الكهربية الساكنة)، تؤثر على البشر مباشرة، وتعمل على خلق خلل في الصحة والبيئة، وفي ما يلي بعض الأضرار الناجمة عن تعرض الإنسان إلى المجال الكهرومغنطيسي.
  وقد وضحت  الدراسة تأثير الكهربية الساكنة على انسان مدينة السليل في المملكة العربية السعودية. وأظهرت أنه يكون لها تأثير واضح على الجهاز العصبي لإنسان هذه المنطقة  في الأشهر التي  تكون عالية الرطوبة. كما تم الحصول على المقارنة في تأثيرها  بين بين الرجال والنساء.

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Association Study using SNP in DNA for Melanoma محمد ناصر الشهراني

I am working now in University of Leeds, In bioinformatics. This study below illustrate the concepts of the research that I am doing.

Genetic association studies test for a correlation between disease status and genetic variation to identify candidate genes or genome regions that contribute to a specific disease. A higher frequency of a single-nucleotide polymorphism (SNP) allele or genotype in a series of individuals affected with a disease can be interpreted as meaning that the tested variant increases the risk of a specific disease (although several other interpretations are also valid; see the following sections). SNPs are the most widely tested markers in association studies (and this term will be used throughout), but microsatellite markers, insertion/deletions, variable-number tandem repeats (VNTRs), and copy-number variants (CNVs) are also used.

Association studies are a major tool for identifying genes conferring susceptibility to complex disorders. These traits and diseases are termed “complex”...

Removal of Dyes from Aqueous Solutions using Styrene/Acrylic acid / Organophilic Montmorillonite Nanocomposite prepared by gamma radiation منال فوزي أبوطالب
Organophilic montmorillonite (OMMT) was synthesized by cationic exchange reaction of Na1-MMT and vinyl benzyl triethyl ammonium chloride (VBTAC) as a reactive organic modifier in an aqueous solution. A series of styrene (St)/acrylic acid (AA)/OMMT nanocomposite hydrogel containing different wt % of OMMT was synthesized through in situ polymerization using g-ray. The samples were characterized using Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), and transmission electron microscope (TEM), whereas thermal stability was examined by thermogravimetric analysis (TGA). The adsorption capacity and rate for both Acid Green B (anionic) and Maxilon C.I. Basic (cationic) dye including adsorption kinetics and isotherm were investigated at 30C. TEM measurements showed spherical nanosized particles of average diameter 30–40 nm and XRD suggested the formation of exfoliated nanocomposite. TGA measurements showed that the addition of OMMT did not enhance the thermal stability where the onset temperature of the degradation for all samples was around 125C. The effect of some important parameters on dye adsorption such as solution pH, initial dye concentration, and contact time was investigated. The equilibrium data obtained in batch experiments were correlated to Langmuir and Freundlich isotherm equations. Results showed that the adsorption of Acid Green B fitted well to the Langmuir model while the adsorption pattern of Maxilon C.I. Basic followed the Freundlich isotherm, which suggests heterogeneity of the adsorption sites on the nanocomposite. ...
Sustained delivery of Hydrocortisone acetate by Chitosan/ N-vinyl-2-pyrrolidone/ CaCO3 microparticle hybrid hydrogels. منال فوزي أبوطالب
The goal of this research is to develop a composite hydrogel system for sustained release of therapeutic agents. The hybrid hydrogels were prepared by radiation crosslinking on aqueous solution of Chitosan (CS)/N-vinyl-2-pyrrolidone (NVP) with different loads of CaCO3 in the presence of hydrocortisone acetate (HCA), an anti-inflammatory drugs. Physical characteristics of CS/NVP/CaCO3 were studied using X-ray diffraction (XRD) and infrared spectrophotometery (IR). The porous structure of resulted hydrogel was confirmed by SEM micrographs. The effect of doses and calcium carbonate amount on the swelling of the hydrogels was investigated. The ability of the prepared CS/NVP/CaCO3-based hybrid hydrogels to be used as drug carriers for anti-inflammatory-specific drug delivery system was estimated using HCA as a model drug. ...
Radiation synthesis of multifunctional polymeric hydrogels for oral delivery of insulin منال فوزي أبوطالب
Polyelectrolyte crosslinked hydrogel was synthesized using gamma radiation-induced copolymerization of methacrylic acid (MAA), N,N-dimethyl aminoethyl methacrylate (DMAEMA) in aqueous solution to utilize for oral delivery of insulin. The influence of copolymer composition and pH value of the surrounding medium on the type of water diffusion in the glassy polymer was discussed. In addition, the swelling kinetics tests on MAA/DMAEMA (90/10) reveal that the swelling kinetics of the proposed hydrogel follows a Fickian diffusion process in media of pH 5, and an anomalous diffusion process in media of pH 1.5 and 7.2. The cross-linked three-dimensional polymers were characterized by scanning electron microscopy and FT-IR. In the matrices with increase in the content of MAA had shown increased bioadhesivity. Insulin was entrapped in these gels and the in vitro release profiles were established separately in both (SGF, pH 1.5) and (SIF, pH 7.2). The release profile of insulin showed negligible release in acidic media (SGF, pH 1.5) and sustained release in simulated intestinal fluid (SIF, pH 7.2). Drug release studies showed that the increasing content of MAA in the copolymer enhances release in SIF to design and improve insulin release behavior from these carriers. ...
19- Synthesis and Characterization of poly(acrylic acid)-g-Sodium Alginate Hydrogel Initiated by Gamma Irradiation for Controlled Release of Chlortetracycline HCl منال فوزي أبوطالب
pH-Sensitive hydrogel was synthesized by gamma radiation crosslinking for sodium alginate extracted from the marine brown alga Turbinaria decurrens and acrylic acid. Preparation of the hydrogels involved free radical polymerization of a combination of acrylic acid (w = 0.2) and different contents of sodium alginate (w = 0.05, 0.10, and 0.15) in aqueous solution using gamma rays of a 60Co source at an irradiation dose rate of 1.2 kGy/h. The swelling behavior of the prepared hydrogel was determined by investigating the swelling time, pH of medium, and alginate content in the hydrogel. The results showed that the hydrogel reached the equilibrium swelling state in water after 6 h. The hydrogel was found to be pH responsive. The drug loading and in vitro release properties of the hydrogel were also evaluated using chlortetracycline hydrochloride as the model drug. The adsorption isotherm studies by batching techniques under the effect of different initial feed concentrations of drug, different pH values, and different sodium alginate content of the adsorbent hydrogel were investigated. The diffusion of chlortetracycline hydrochloride within the hydrogel was found to be of non-Fickian character. The kinetic parameters such as the diffusion exponent, diffusion constant, and diffusion coefficient were also evaluated. ...
Cloning and Expression Profiling of Polycomb Gene, VERNALIZATION INSENSITIVE 3 from Tomato Solanum lycopersicum L زينب ماجد طاهر المطيري

In many plant species, exposure to a prolonged period of cold during the winter promotes flowering in the spring, a process termed vernalization. VERNALIZATION INSENSITIVE 3 (VIN3) is a chromatin remodelling protein that is induced by low temperatures and is required for the vernalization response in Arabidopsis thaliana. VIN3 is one of the PcG proteins, which mediates epigenetic repression of FLOWERING LOCUS C (FLC) in A. thaliana. Here, we present cloning, characterization and expression of a putative SlVIN3 gene in tomato (Solanum lycopersicum L.) by isolating cDNA clones corresponding to SlVIN3 gene using primers designed based on conserved sequences between PcG genes in A. thaliana and tomato. The SlVIN3 cDNAs were cloned into pBS plasmid and sequenced. Both 5' and 3' RACE were generated and sequenced. The flcDNA for SlVIN3 gene of 2,823 bp length was composed of 5'UTR (336 bp), ORF (2,217 bp) and 3'UTR (270 bp). The translated ORF encodes a polypeptide of 739 amino acids. Alignment of deduced amino acids indicated that there are highly conserved regions between tomato SlVIN3 predicted protein and plant VIN3 gene family members. Both unrooted phylogenetic trees constructed using maximum parsimony and maximum likelihood methods indicated that there is a close relationship between SlVIN3 predicted protein and VIN3 protein of Vitis vinifera. The expression of SlVIN3 remained high during floral organ differentiation and growth and decreased to its lowest level when the fruit starts to develop.

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