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Search Results: 1 - 10 of 401332 matches for " M. M. Matar "
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Existence of solution to fractional nonlinear backward differential equations on Banach spaces
M. M. Matar
International Journal of Mathematical Analysis , 2012,
Abstract:
On existence of solution to some nonlinear differential equations of fractional order 2 < alpha leq 3
M. M. Matar
International Journal of Mathematical Analysis , 2012,
Abstract:
Existence and uniqueness of solutions to fractional semilinear mixed Volterra-Fredholm integrodifferential equations with nonlocal conditions
Mohammed M. Matar
Electronic Journal of Differential Equations , 2009,
Abstract: In this article we study the fractional semilinear mixed Volterra-Fredholm integrodifferential equation $$ frac{d^{alpha }x(t)}{dt^{alpha }} =Ax(t)+fBig(t,x(t), int_{t_0}^tk(t,s,x(s))ds,int_{t_0}^{T}h(t,s,x(s))dsBig) , $$ where $tin [t_0,T]$, $t_0geq 0$, $0
Catalytic Polymerization of Acrylonitrile by Khulays Bentonite
Matar M. Al-Esaimi
Bulletin of Chemical Reaction Engineering & Catalysis , 2007, DOI: 10.9767/bcrec.2.1.4.6-10
Abstract: The aqueous polymerization of acrylonitrile (AN) catalyzed with exchanged Khulays bentonite . The influence of various polymerization parameters ( e.g., concentrations of Potassium Persulfate (K2S2O8) and monomer , various of organic solvents, and different temperature has been investigated. It was found that the rate of polymerization of AN was found to be dependent on monomer concentration, initiator and temperature. The activation energy of polymerization was calculated .Thermal properties of the polymer were studied by TGA and DSC techniques. 2007 CREC UNDIP. All rights reserved. Received: 5 February 2007; Received in revised: 19 April 2007; Accepted: 7 May 2007 [How to Cite: M. M. Al-Esaimi. (2007). Catalytic Polymerization of Acrylonitrile by Khulays Bentonite. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3): 32-36. doi:10.9767/bcrec.2.1.4.6-10] [How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2.1.4.6-10 ]
Structural stability and magnetism of FeN from first principles
A. Houari,S. F. Matar,M. A. Belkhir,M. Nakhl
Physics , 2009,
Abstract: In the framework of density functional theory (DFT), the structural and magnetic properties of FeN mono nitride have been investigated using the all electrons augmented spherical wave method (ASW) with a generalized gradient GGA functional for treating the effects of exchange and correlation. Calculation of the energy versus volume in hypothetic rocksalt (RS), zinc-blende (ZB) and wurtzite (W) types structures shows that the RS-type structure is more stable than the others. Spin polarized calculation results at equilibrium volume indicate that the ground state of RS-FeN is ferromagnetic with a high moment, while ZB-FeN and W-FeN are non magnetic. The influence of distortions on the stability is taken into account by considering FeN in two different face-centred tetragonal structures (fct): fct-rocksalt and fct-zincblende. The magnetovolume effects with respect to Slater-Pauling-Friedel model are discussed. The electronic structures analyzed from site and spin projected density of states are reported. A discussion of the structural and magnetic properties of FeN is given with respect to N local environment of Fe.
Biological activities of the hydro-alcoholic and aqueous extracts of Achillea fragrantissima (Forssk.) grown in Jordan  [PDF]
Hana M. Hammad, Suzan A. Matar, Simona-Carmen Litescu, Sawsan Abuhamdah, Hala I. Al-Jaber, Fatma U. Afifi
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.61005
Abstract:

Aqueous and hydro-alcoholic extracts of Achillea fragrantissima L. (Asteraceae) grown in Jordan were screened for their antioxidant, antimicrobial, antiplatelet, anti-proliferative and acetylcholinesterase (AChE) inhibition efficacy. Total phenols and flavonoids were determined colorimetrically. The radical scavenging activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activity assays. High performance liquid chromatography-mass spectrometry (HPLCMS) analysis resulted in the identification of 7 phenolic compounds in the hydro-alcoholic extract and 4 compounds in the aqueous extract; quercetin 3-β-D-glucoside was the main component for both extracts. Antimicrobial activities were determined by antimicrobial susceptibility testing such as agar well-diffusion method, minimum inhibition concentration and minimum bactericidal concentration. Gram positive bacteria showed sensitivity to hydro-alcoholic extract in the agar-well diffusion test. No significant activity was observed against gram negative bacteria and Candida albicans. Hydro-alcoholic extract had a bactericidal activity against Streptococcus pneumoniae and Bacillus cereus at high concentrations (MIC 12.5 mg/ml) rather than inhibitory effect. In vitro antiplatelet activity was tested on human whole blood using an electrical impedance method. At concentrations (50, 100, and 200 μg/ml), no effect on platelet aggregation was noticed. Anti-proliferative activity was investigated using the MTT assay. At concentrations up to 200 μg/ml, extracts did not possess cytotoxic activity against the MCF-7 cells. Acetylcholinesterase (AChE) inhibitory capacity of A. fragrantissima extracts was tested using TLC assay method, and neither aqueous, nor hydroalcoholic extracts showed AChE inhibition. The present investigation supported

Studies on 2-Arylhydrazononitriles: Synthesis of 3-Aryl-2-arylhydrazopropanenitriles and Their Utility as Precursors to 2-Substituted Indoles, 2-Substituted-1,2,3-Triazoles, and 1-Substituted Pyrazolo[4,3-d]pyrimidines
Khaled D. Khalil,Hamad M. Al-Matar
Molecules , 2012, DOI: 10.3390/molecules171012225
Abstract: Coupling of 2-benzylmalononitrile with aromatic diazonium salts afforded 3-phenyl-2-arylhydrazonopropanenitriles 4a,b, which were rearranged into 2-cyanoindoles 5a,b upon heating with ZnCl2 in the presence of glacial acetic acid. The produced indole derivatives 5a,b can be successfully used as valuable precursors to synthesize 1,2,4-oxadiazolylindoles 8a,b. The reaction of arylhydrazononitriles 4a,b with hydroxylamine afforded an amidoximes 9a,b that could be cyclized into 1,2,3-triazole-4-amines 10a,b. In addition, 4a,b could be converted into 4-aminopyrazoles 12a,b via condensation with chloroacetonitrile in the presence of triethylamine as a basic catalyst. Finally, compounds 12a,b were refluxed with dimethylformamide dimethylacetal (DMFDMA) to afford amidines 13a,b that were readily cyclized to the corresponding pyrazolo[4,3-d]pyrimidines 14a,b when refluxed with ammonium acetate.
Influence of organic matter from urban effluents on trace metal speciation and bioavailability in river under strong urban pressure
Matar Z.,Varrault G.,Chebbo G.,Troupel M.
E3S Web of Conferences , 2013, DOI: 10.1051/e3sconf/20130124002
Abstract: In aquatic systems, dissolved organic matter (DOM) constitutes a key component of the carbon cycle controlling the transport, speciation, bioavailability and toxicity of trace metals. In this work, we study the spatio-temporal variability of the MO in terms of both quality and quantity from upstream to downstream the Parisian conurbation. Urban discharges which are the main source of allochthonous organic matter into the Seine at low water periods were also investigated. The DOM collected was fractionated according to polarity criteria into five fractions: hydrophobic, transphilic, hydrophilic acid, hydrophilic basic and hydrophilic neutral. Due to urban discharges a strong enrichment in the hydrophilic (HPI) fraction was observed for downstream sites. This hydrophilic fraction presented stronger binding capacities for copper than hydrophobic fraction from less urbanized site (upstream from Paris) and than Suwannee river fulvic acid (SRFA). Furthermore, biotests highlighted a significant copper bioavailability decrease in presence of hydrophilic DOM.
Erlotinib Preserves Renal Function and Prevents Salt Retention in Doxorubicin Treated Nephrotic Rats
Raed N. Bou Matar, Janet D. Klein, Jeff M. Sands
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054738
Abstract: Nephrotic syndrome is associated with up-regulation of the heparin-binding epidermal growth factor (HB-EGF). Erlotinib blocks the activation of the epidermal growth factor receptor (EGFR) in response to HB-EGF. This study investigates the effect of Erlotinib on the progression of proteinuria, renal dysfunction, and salt retention in doxorubicin treated nephrotic rats. Male rats were divided into 3 pair-fed groups (n = 13/group) as follows: Control rats (Ctrl); rats receiving intravenous doxorubicin (Dox); and rats receiving intravenous doxorubicin followed by daily oral Erlotinib (Dox + Erl). Upon establishment of high grade proteinuria, urine sodium and creatinine clearance were measured. Kidney tissue was dissected and analyzed for γ-epithelial sodium channel (γENaC), sodium-potassium -chloride co-transporter 2 (NKCC2), sodium chloride co-transporter (NCC), aquaporin 2 (AQP2), and EGFR abundances using western blot. Creatinine clearance was preserved in the Dox + Erl rats as compared to the Dox group (in ml/min: Ctrl: 5.2±.5, Dox: 1.9±0.3, Dox + Erl: 3.6±0.5). Despite a minimal effect on the degree of proteinuria, Erlotinib prevented salt retention (Urinary Na in mEq/d: Ctrl: 2.2±0.2, Dox: 1.8±0.3, Dox + Erl: 2.2±0.2). The cleaved/uncleaved γENaC ratio was increased by 41±16% in the Dox group but unchanged in the Dox + Erl group when compared to Ctrl. The phosphorylated EGFR/total EGFR ratio was reduced by 74±7% in the Dox group and by 77±4% in the Dox + Erl group. In conclusion, Erlotinib preserved renal function and prevented salt retention in nephrotic rats. The observed effects do not appear to be mediated by direct blockade of EGFR.
Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation
Khaled D. Khalil,Hamad M. Al-Matar
Molecules , 2013, DOI: 10.3390/molecules18055288
Abstract: Chitosan-grafted-poly(4-vinylpyridine) (Cs-PVP) copolymers could be synthesized under heterogeneous conditions in presence of a potassium persulfate and sodium sulfite redox system. The synthesized graft copolymer could be utilized effectively, in the form of beads, as an efficient catalyst for Michael additions of active methylenes to functionally substituted alkenes. Moreover, methyl moiety oxidation in methyl pyridazinyl carbonitriles by H 2O 2 in the presence of chitosan-g-polyvinyl pyridine–supported iron (III) complex, Cs-PVP/Fe, could be affected. A variety of pyrans, naphthopyrans, and thiopyrans could be synthesized efficiently in the presence of these graft copolymer beads by novel catalytic routes. These polymeric catalysts could be used instead of the old toxic commercial organic basic catalysts, piperidine or pyridine, and could be readily isolated from the reaction mixture and recycled several times without significant loss of catalytic activity.
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