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61.
Moamen S. Refat Gehad G. Mohamed Mohamed Y. S. Ibrahim Hamada M. A. Killa Hammad Fetooh 《Russian Journal of General Chemistry》2013,83(12):2479-2487
Solid complexes have been prepared and characterized by IR, UV-Vis, elemental analysis, and 1H NMR. Indomethacin forms complexes with Cd(II), Ce(III), and Th(IV) ions in molar ratios (ligand: metal) (2: 1), (3: 1), and (4: 1), respectively. The IR spectra of the complexes suggest that the Indomethacin behaves as a monobasic monodentate ligand coordinated to the metal ions via the deprotonated carboxylate group. Prepared complexes exhibit higher antimicrobial activity against several microorganisms, compared to free ligand. 相似文献
62.
Eric D. Merkley Erin S. Baker Kevin L. Crowell Daniel J. Orton Thomas Taverner Charles Ansong Yehia M. Ibrahim Meagan C. Burnet John R. Cort Gordon A. Anderson Richard D. Smith Joshua N. Adkins 《Journal of the American Society for Mass Spectrometry》2013,24(3):444-449
Chemical cross-linking of proteins followed by proteolysis and mass spectrometric analysis of the resulting cross-linked peptides provides powerful insight into the quaternary structure of protein complexes. Mixed-isotope cross-linking (a method for distinguishing intermolecular cross-links) was coupled with liquid chromatography, ion mobility spectrometry and mass spectrometry (LC-IMS-MS) to provide an additional separation dimension to the traditional cross-linking approach. This method produced multiplet m/z peaks that are aligned in the IMS drift time dimension and serve as signatures of intermolecular cross-linked peptides. We developed an informatics tool to use the amino acid sequence information inherent in the multiplet spacing for accurate identification of the cross-linked peptides. Because of the separation of cross-linked and non-cross-linked peptides in drift time, our LC-IMS-MS approach was able to confidently detect more intermolecular cross-linked peptides than LC-MS alone. 相似文献
63.
Sazlinda Kamaruzaman Peter C. Hauser Mohd Marsin Sanagi Wan Aini Wan Ibrahim Salasiah Endud Hong Heng See 《Analytica chimica acta》2013
A simple adsorption/desorption procedure using a mixed matrix membrane (MMM) as extraction medium is demonstrated as a new miniaturized sample pretreatment and preconcentration technique. Reversed-phase particles namely polymeric bonded octadecyl (C18) was incorporated through dispersion in a cellulose triacetate (CTA) polymer matrix to form a C18-MMM. Non-steroidal anti-inflammatory drugs (NSAIDs) namely diclofenac, mefenamic acid and ibuprofen present in the environmental water samples were selected as targeted model analytes. The extraction setup is simple by dipping a small piece of C18-MMM (7 mm × 7 mm) in a stirred 10 mL sample solution for analyte adsorption process. The entrapped analyte within the membrane was then desorbed into 100 μL of methanol by ultrasonication prior to high performance liquid chromatography (HPLC) analysis. Each membrane was discarded after single use to avoid any analyte carry-over effect. Several important parameters, such as effect of sample pH, salting-out effect, sample volume, extraction time, desorption solvent and desorption time were comprehensively optimized. The C18-MMM demonstrated high affinity for NSAIDs spiked in tap and river water with relative recoveries ranging from 92 to 100% and good reproducibility with relative standard deviations between 1.1 and 5.5% (n = 9). The overall results obtained were found comparable against conventional solid phase extraction (SPE) using cartridge packed with identical C18 adsorbent. 相似文献
64.
Dadan Hermawan Izdiani Mohd Yatim Khaulah Ab Rahim Mohd Marsin Sanagi Wan Aini Wan Ibrahim Hassan Y. Aboul-Enein 《Chromatographia》2013,76(21-22):1527-1536
A simple solid phase extraction (SPE) method coupled with high performance liquid chromatography (HPLC) using UV detector and microemulsion electrokinetic chromatography (MEEKC) has been developed and compared for the quantitative determination of miconazole nitrate in pharmaceutical formulation. For HPLC method, two parameters were optimized, namely, the wavelength and the mobile phases. The optimized condition was at the 225 nm wavelength and the mobile phase of ACN:MeOH (90:10 v/v). There are seven MEEKC parameters that were optimized, in this research, which were applied to voltage, temperature, wavelength, sodium dodecyl sulfate (SDS) concentration, buffer pH, buffer concentration and butan-1-ol concentration. The optimum MEEKC condition was obtained using 86.35 % (w/w) 2.5 mM borate buffer pH 9, 0.25 % (w/w) SDS, 0.8 % (w/w) ethyl acetate, 6.6 % w/w butan-1-ol and 6.0 % (w/w) acetonitrile. The combination of SPE using a diol column with HPLC–UV and the MEEKC methods were successfully applied for the determination of miconazole nitrate in a pharmaceutical formulation with the recovery percentage of 98.35 and 92.50 %, respectively. 相似文献
65.
Radia Bouasla Hadjira Berredjem Malika Berredjem Malika Ibrahim‐Oualid Assia Allaoui Marc Lecouvey Nour‐Eddine Aouf 《Journal of heterocyclic chemistry》2013,50(6):1328-1332
A new series of chiral 5‐substituted bis‐oxazolidinones containing an acylsulfonamide moiety has been synthesized starting from chlorosulfonyl isocyanate, (l )‐ethyl lactate, and oxazolidin‐2‐ones. All the reactions were conducted at ambient temperature, and the N‐acylsulfonamide bis‐oxazolidin‐2‐ones were obtained with high yields within 2 h. Some of the newly synthesized compounds were evaluated in vitro against the virulent strain RH of Toxoplasma gondii and the human lymphocytes, and showed promising results. 相似文献
66.
Ibrahim Kayali Mohammad Karaein Khawla Qamhieh Salam Wadaah Wisam Ahmad Ulf Olsson 《Journal of Dispersion Science and Technology》2013,34(1):10-17
Bicontinuous and water-in-diesel microemulsions were formulated using single nonionic alkyl poly glycol ethers combined with hydrophilic alcohol ethoxylates. The phase behavior at temperatures ranging from 0°C to 50°C was investigated. Visual inspection as well as cross-polarizers were used to detect anisotropy. The fish phase diagrams were determined. The presence of the hydrophilic alcohol ethoxylates was necessary to initiate both types of microemulsions. Increasing the hydrophobic chain length of the surfactant led to a wider range of temperature stability at lower surfactant concentration. Meanwhile, increasing the ethylene oxide units in the headgroup by two units led to a phase diagram that is dominated by lyotropic liquid crystal. The formulated water in diesel microemulsions were tested experimentally in a 4-cylinder diesel engine. From this it is observed that the emissions of NOx, soot, and CO2 were reduced substantially compared to neat diesel, while for the CO the reduction occurs just at low load. 相似文献
67.
A.-H. Abdel-Rahman Adel E. El Aassy Ibrahim Y. Ahmed Fadia F. Hamza Mohammed 《Journal of Dispersion Science and Technology》2013,34(8):1128-1135
Synthesis of poly(acrylamidoxime) resin from polyacrylonitrile performed with different crosslinking ratios 2, 5, and 10 wt% of divinylbenzene as crosslinking agent, using methylbenzoate and dioctylphthalate as pore producing solvent, the reaction mixture occurred under nitrogen. Studies carried out on diluted solution from rare earth elements (REEs) concentrate contains impurities as Cu2+, Ni2+, Zn2+, Fe3+, Al3+, Si4+, Th4+, U6+, Ca2+, and K+. Changing some parameters as pH of the solution, time of feeding and type of acid as HCl, HNO3, H2SO4. The adsorption efficiency of resin is in the order pH 6 > pH 5 > pH 4 > pH 2 with excluding pH 6 due to the precipitation of some of REEs with the impurities and complete precipitation of Dy ion during pH adjustment, the adsorption in HNO3 > HCl > H2SO4 media. 相似文献
68.
Kareem AbuBakr Soliman Howida Kamal Ibrahim Mahmoud Mohamed Ghorab 《Journal of Dispersion Science and Technology》2013,34(8):1127-1133
Risperidone is an atypical antipsychotic drug used to treat schizophrenia. This study aims to formulate risperidone as effervescent tablets to improve patient compliance. Different nanoemulsion combinations were loaded with risperidone to improve its poor water solubility then adsorbed on Aeroperl. The formula showing highest drug dissolution was formulated as effervescent tablets. Factorial design was applied for different tablet formulation variables and the prepared formulae were tested for different criteria in comparison with their corresponding formulae containing drug without nanoemulsion formulation. Statistical analysis was used to determine the most desirable tablet formula considering its Carr index, effervescence time, and drug release. 相似文献
69.
Ibrahim A. Radini 《Liquid crystals》2013,40(12):1417-1430
The synthesis and mesomorphic properties of a systematic range of ortho difluoroterphenyls with a bulky terminal chain are detailed. The bulky terminal chain consists of either a tertiarybutyl group or a trimethylsilyl unit, each separated from the core by a short (dimethylene) chain, with the other terminal chain being either octyloxy or heptyl. The synthesis of the materials was affected efficiently using a combination of low temperature lithiations and palladium-catalysed cross-coupling reactions. Unusually for liquid crystals with bulky terminal chains, the smectic phase stability (particularly smectic C) is upheld by more than the nematic phase stability, and in most cases the smectic C phase stability is actually higher than comparable analogues with conventional unbranched terminal chains. It is postulated that the surprisingly high smectic C phase stability results from a phase separation effect due to the incompatibility of the spherical bulky group and the conventional unbranched terminal chain, hence implying that the smectic ‘layers’ are well defined, and such definition of the layers bodes well for bookshelf geometry in ferroelectric mixtures. 相似文献
70.
Ibrahim O. Mohamed 《Applied biochemistry and biotechnology》2013,171(3):655-666
Cocoa butter equivalent (CBE) was prepared by enzymatic acidolysis reaction of substrate consisting of refined palm mid fraction oil and palmitic–stearic fatty acid mixture. The reactions were performed in a batch reactor at a temperature of 60 °C in an orbital shaker operated at 160 RPM. Different mass ratios of substrates were explored, and the composition of the five major triacylglycerols (TAGs) of the structured lipids was identified and quantified using cocoa butter certified reference material IRMM-801. The reaction resulted in production of cocoa butter equivalent with the TAGs' composition (1,3-dipalmitoyl-2-oleoyl-glycerol 30.7 %, 1-palmitoyl-2-oleoyl-3-stearoyl-rac-glycerol 40.1%, 1-palmitoy-2,3- dioleoyl glycerol 9.0 %, 1,3-distearoyl-2-oleoyl-glycerol 14.5 %, and 1-stearoyl-2,3-dioleoyl glycerol 5.7 %) and with onset melting temperature of 31.6 °C and peak temperature of 40.4 °C which are close to those of cocoa butter. The proposed kinetics model for the acidolysis reaction presented the experimental data very well. The results of this research showed that palm mid fraction oil TAGs could be restructured to produce value added product such as CBE. 相似文献