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71.
Anas M. Abdel Rahman Andreas L. Lopata Robyn E. O'Hehir John J. Robinson Joseph H. Banoub Robert J. Helleur 《Journal of mass spectrometry : JMS》2010,45(4):372-381
The protein tropomyosin (TM) is a known major allergen present in shellfish causing frequent food allergies. TM is also an occupational allergen generated in the working environment of snow crab (Chionoecetes opilio) processing plants. The TM protein was purified from both claw and leg meats of snow crab and analyzed by electrospray ionization and matrix‐assisted laser desorption/ionization (MALDI) using hybrid quadruple time‐of‐flight tandem mass spectrometry (QqToF‐MS). The native polypeptide molecular weight of TM was determined to be 32 733 Da. The protein was further characterized using the ‘bottom‐up’ MS approach. A peptide mass fingerprinting was obtained by two different enzymatic digestions and de novo sequencing of the most abundant peptides performed. Any post‐translational modifications were identified by searching their calculated and predicted molecular weights in precursor ion spectra. The immunological reactivity of snow crab extract was evaluated using specific antibodies and allergenic reactivity assessed with serum of allergic patients. Subsequently, a signature peptide for TM was identified and evaluated in terms of identity and homology using the basic local alignment search tool (BLAST). The identification of a signature peptide for the allergen TM using MALDI‐QqToF‐MS will be critical for the sensitive and specific quantification of this highly allergenic protein in the work place. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
72.
Rifaat Hilal Ahmed A. Abdel Khalek Shabaan A. K. Elroby 《International journal of quantum chemistry》2005,103(3):332-343
The ground‐state equilibrium geometries of benzothiazole, benzoxazole, and benzimidazole were optimized at the density functional theory (DFT)/6‐31G** level of theory. Proton affinities on each of the possible sites in the studied series of compounds have been calculated at the DFT/6‐31G**/6‐311++G** level. The results indicate clearly that N‐site protonation is strongly favored over X‐site protonation (X = NH, O, S) for the series studied. Correlation of the computed proton affinities to the energy (EHOMO) of the highest occupied MO in the gas phase and in solution has been explored and discussed. A comprehensive investigation of the effect of solvent on the process of protonation of the studied compounds has been performed. Different dielectric continuum models (i.e., Onsager, PCM, and IPCM) have been tested; their performance and range of applicability are reported and discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 相似文献
73.
W.S. Abdel Halim 《Applied Surface Science》2007,253(22):8974-8980
The adsorption of carbon monoxide at the defect-free (1 0 0), (1 1 0) and (2 1 0) five-atomic layer slab of the three oxides: MgO, CaO, and SrO has been investigated using the periodic Hartree-Fock level of ab initio theory, together with the 1 × 1 supercell model. All the calculated CO/oxide interaction energies exhibit exothermic character. The HF interaction energies increase monotonically in the order MgO < CaO < SrO. The surface morphology of adsorbate/substrate interaction is confirmed by considering relaxation energies, Mulliken population analysis, charge density contours, and electrostatic potential maps. 相似文献
74.
The effects of surface tension and adsorption on the electrohydrodynamic Kelvin-Helmholtz instability are studied. The system is stressed by a normal electric field such that it allows for the presence of surface charges at the interface. The method used is that of multiple scales. The nonlinear Schrödinger equation describing the behavior of the disturbed system is derived. The stability of the perturbed system is discussed both analytically and numerically and the stability diagrams are obtained. At the critical point, a generalized formulation of the evolution equation is developed, which leads to the nonlinear Klein-Gordon equation. The various stability criteria are derived from this equation. 相似文献
75.
76.
Exploiting the 1,2,3‐Triazole Moiety to Generate Carbazole Molecular Architectures through Click Approach
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Mohamed A. Ameen Kamal M. El‐Shaieb Asmaa H. Mohamed Fathy F. Abdel‐Latif 《Journal of heterocyclic chemistry》2015,52(6):1718-1722
Reaction of 3,6‐dichlorocarbazole with propargyl bromide in the presence of a basic medium gave an N‐propargylated carbazole. The latter compound was converted into molecular architectures containing 1,2,3‐triazole moiety through Cu(I)‐catalyzed 1,3‐cycloaddition reaction with different azides. Similarly, 2‐azidomethyl benzothiazole was cliched with N‐Boc‐protected N´‐propargyl glutamate to give the biomolecule 2‐triazolylmethyl product. 相似文献
77.
Aziz N. Abdel 《Fluid Dynamics》1993,28(5):736-738
The phenomenon of thermal relaxation of the gas bubbles in a fluid behind a shock front is analyzed. The approach to solving the problem of heat transfer between a gas bubble and a fluid developed by the author is used to obtain a solution describing the initial stage of bubble collapse behind the shock front.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 5, pp. 187–189, September–October, 1993. 相似文献
78.
Synthesis,Reactions, Characterization and Biological Evaluation of 2,3′‐Bipyridine Derivatives (III)
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Fawzy A. Attaby Azza M. Abdel‐Fattah Labeeb M. Shaif Mohamed M. Elsayed 《Journal of heterocyclic chemistry》2014,51(4):927-936
1‐Pyridin‐3‐yl‐3‐(2‐thienyl of 2‐furyl)prop‐2‐en‐1‐ones 1a , 1b reacted with 2‐cyanoethanethioamide 2 to afford the corresponding 4‐(thiophen‐2‐yl or furan‐2‐yl)‐6‐sulfanyl‐2,3′‐bipyridine‐5‐carbonitriles 3a , 3b . The synthetic potentiality of compounds 3a , 3b were investigated in the present study via their reactions with several active halogen containing compounds 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 5 , 5a , 5b . Our aim here is the synthesis of 4‐(2‐thienyl or 2‐furyl)‐6‐pyridin‐3‐ylthieno[2,3‐b]pyridin‐3‐amines 6a , 6b , 6c , 6d , 6e , 6g , 6h , 6i , 6j , 6k , 6l , 6m , 6n ,via 6‐(alkyl‐thio)‐4‐(2‐thienyl or 2‐furyl)‐2,3′‐bipyridine‐5‐carbonitriles 5a , 5b , 5c , 5d , 5e , 5i , 5j , 5k , 5l , 5m . The structures of all newly synthesized heterocyclic compounds were elucidated by considering the data of IR, 1H‐NMR, mass spectra, as well as that of elemental analyses. Anti‐cancer, anti‐Alzheimer, and anti‐COX‐2 activities were investigated for all the newly synthesized heterocyclic compounds. 相似文献
79.
Synthesis of Novel Modified Guanidines: Reaction of Dicyandiamide with Amino Acids,Amides, and Amines in Aqueous Medium
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Ahmed M. Soliman Shaaban K. Mohamed Mahmoud. Abd El Aleem. Ali. Ali. El‐Remaily H. Abdel‐Ghany 《Journal of heterocyclic chemistry》2014,51(5):1322-1326
Reaction of dicyandiamide with series of amino acids afforded guanidinyl pyrazolones 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , respectively. Although reaction of dicyandiamide with urea, acetamide, bezamide, allantion, p‐aminobenzoic acid, sulphanilic acid, and adenine gave biguanides 20 , 21 , 22 , 23 , 24 , 25 , 26 , respectively. All compounds have been characterized on the basis of IR and 1H‐NMR. 相似文献
80.
Ahmed M. M. Soliman Mahmoud. Abd El‐Aleem. Ali. Ali. El‐Remaily Adel. A. Sultan Hossam. Abdel‐Ghany 《Journal of heterocyclic chemistry》2014,51(5):1476-1481
5‐Amino‐3‐anilino‐1H‐pyrazole‐4‐carbonitrile 1 was alkylated with various halo reagents under phase transfer conditions to give the corresponding imidazopyrazole derivatives 2a , 2b , 2c , 3 , 4 , 5 , 6 . Pyrazolo[1,5‐a] pyrimidine derivatives 11 , 12 , 13 , 14 were prepared by treating compound 1 with different dicarbonyl reagents, namely, diethymalonate, ethyl 3‐oxo‐3‐phenylpropanoate, pentane‐2,4‐dione or ethyl 3‐oxobutanoate. 相似文献