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161.
AbstractDiphenyl-4-thioxo-1,4-dihydropyrimidin-5-yl)ethan-1-one 4 was obtained upon the reaction of (phenylamino)but-2-enethioyl)benzamide 3 with sodium hydroxide. The reactions of 4 with several active species such as benzaldehyde, urea, malononitrile, ethyl cyanoacetate, hydrazine, and carbon disulfide were studied. The antitumor activities of some selective compounds were examined against two cell lines: Mammalian cell lines: A-549 cells (human lung cancer cell line) and MRC-5 cells (normal human lung fibroblast cell line); some of the compounds were highly efficient; compound 13 has the most effective anticancer activity. 相似文献
162.
Spectroscopic,DFT and antimicrobial activity of Zn(II), Zr(IV), Ce(IV) and U(VI) complexes of N,N‐ chelated 4,6‐bis (4‐chlorophenyl)‐2‐amino‐1,2‐dihydropyridine‐3‐carbinitrile
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Four novel metal complexes of 4,6‐bis (4‐chlorophenyl)‐2‐amino‐1,2‐dihydropyridine‐3‐carbinitrile (H2L) with Zn(II), Zr(IV), Ce(IV) and U(VI) were synthesized. The structure was elucidated using elemental analysis, melting point, molar conductivity; spectroscopic techniques (IR, 1H NMR, UV–Vis., mass spectra) as well as thermo gravimetric analysis. The spectroscopic data proved that H2L chelated with the metal ions as a bidentate ligand through Namino and Ncarbinitrile atoms. The molecular structure of the complexes was determined using density functional theory (DFT). The central metal ion in each complex is six‐coordinate and the angles around it vary from 62.74° to 166.46°; these values agree with distorted octahedral geometry. The calculated total energy of the complexes found in the region – 406.342 to ?459.717 au and the dipole moment change from 4.675 to 13.171D. The antibacterial and antifungal activities of the ligand, metal salts and complexes were estimated on some microorganisms. The complexes showed significant antibacterial profile in comparison to the free ligand. 相似文献
163.
164.
We perform the linear stability analysis of a new model for poromechanical processes with inertia (formulated in mixed form using the solid deformation, fluid pressure, and total pressure) interacting with diffusing and reacting solutes convected in the medium. We find parameter regions that lead to spatio-temporal instabilities of the coupled system. The mutual dependences between deformation and diffusive patterns are of substantial relevance in the study of morphoelastic changes in bio-materials. We provide a set of computational examples in 2D and 3D (related to brain mechanobiology) that can be used to form a better understanding on how, and up to which extent, the deformations of the porous structure dictate the generation and suppression of spatial patterning dynamics, also related to the onset of mechano-chemical waves. 相似文献
165.
Hamid A. M. Abdel El-Sayed H. A. Mohammed S. M. Moustafa A. H. Morsy H. A. 《Russian Journal of General Chemistry》2020,90(3):476-482
Russian Journal of General Chemistry - The multi-component reaction of diacetyl triazole derivative with ethyl cyanoacetate and various aromatic aldehydes according to the conventional and solvent... 相似文献
166.
Hassan A. El-Sayed Mohamed H. M. Abd Elazim M. G. Assy Islam Atef 《Journal of heterocyclic chemistry》2020,57(4):1974-1980
Herein, the synthesis of nitrogen-containing heterocyclic scaffolds from heterocyclization of cyanoacetic acid hydrazide derivatives is described. Thiosemicarbazide derivative 1a undergoes base-mediated cyclization producing pyrazole derivative of type 2 . The triazolopyridine 5 was obtained by double cyclization of 1a and benzylidene malononitrile. Compound 1b condensed with ethyl chloroformate to furnish pyrazolooxazine 8 . Compound 1b was added to benzoyl isothiocyanate under thermal condition to form oxadiazine derivative 10 while, keeping the above reactant under room temperature to form acyclic derivative 11 . Using CS2 as a cyclizing agent for compound 1b yielded pyrazole derivative 13 . Treatment of 1b with I2 resulted in oxidative cyclization producing pyridazine derivative 14 . Compound 1c cyclized with benzoyl isothiocyanate forming triazolothiazine derivative 18 . While using cinnamoyl isothiocyanate, the acyclic product 22 was obtained. Compound 1c was condensed with formaldehyde leading to oxadiazole derivative 25 . 相似文献
167.
The system of partial differential equations for moving optical solitons in fiber Bragg gratings are studied. The traveling wave reductions are used to look for solutions of the system of equations. The compatibility conditions for the overdetermined system of equations are analyzed and discussed. Periodic and solitary waves in optical fiber gratings are found and illustrated. 相似文献
168.
M. S. Sakr A. Z. Mohamed M. M. A. Shehab A. H. Bassyouni 《Czechoslovak Journal of Physics》1991,41(8):785-792
The steady state creep of Pb-10 wt.% Sn and Pb-61·9 wt.% Sn alloys have been investigated under different constant stresses near the transformation temperature. The temperature dependence of steady creep rate has shown two different transition points; at 423 K for Pb-10 wt.% Sn alloy and at 403 K for Pb-61·9 wt.% Sn (the eutectic composition). The strain rate sensitivity parameter (m) has been found to increase by raising the working temperature and to reach 0·45 and 0·85 for the first and second alloy, respectively. The activation energies of steady state creep of Pb-10 wt. % Sn have been found to be 46·2 kJ/mole and 88·2 kJ/mole in the low and high temperature regions (below and above 423 K) referring to dislocation and self diffusion mechanisms. While activation energies of steady creep in Pb-61·9 wt.% Sn have been found to be 42 kJ/mole and 63 kJ/mole in the low and high temperature region (below and above 403 K), characterizing grain boundary diffusion in Sn and Pb respectively. X-ray analysis and microscopic investigations of the test alloys have confirmed the above mentioned mechanisms. 相似文献
169.
Mohamed A F Elmosallamy 《Analytical sciences》2004,20(2):285-290
Two novel highly selective potentiometric membrane sensors responsive to picrate ion were developed. They are based on the use of N,N'-dibenzoyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DD18C6)-picrate and Kryptofix 222-picrate charge-transfer complexes as novel electroactive materials in poly(vinyl chloride) matrix membranes plasticized with o-nitrophenyloctylether or dioctylphthalate. The sensors show a Nernstian response with anionic slopes of -59.0 +/- 0.1 and -58.0 +/- 0.2 mV decade(-1) over concentration ranges of 6.0 x 10(-5) - 1.0 x 10(-2) and 7.0 x 10(-5) - 1.0 x 10(-2) mol l(-1) picrate ion and pH ranges of 5-11.5 and 5.5-11.5 for DD18C6 and Kryptofix 222 based picrate sensors, respectively. Both sensors show highly selectivity towards picrate ion over many hydrophilic and lipophilic anions, and exhibit a non-Hofmeister selectivity sequence, which is an improvement over methods reported so far. The sensors are used for the titrimetric determination of alkaloids using picrate as a titrant. 相似文献
170.
M.G.A. Khedr S.M.Abd El Haleem A. Baraka 《Journal of Electroanalytical Chemistry》1985,184(1):161-169
Streaming potentials have been measured by the fast pulse method for cellulose acetate membranes cured at 85 and 95°C. Bounding, solutions of Li+, Na+, K+, Cs+, Mg2+, Sr2+, Ba2+ and La3+ chlorides were used in the concentration of 10?4-10?1M. The streaming potenial was shown to depend on the nature of the cation and to increase with decreasing solution concentration.Rather good consistency was obtained in dilute solutions between the electroosmotic cross coefficients calculated from the streaming potentials and from the electroosmosis measurements for Part I (M.G.A. Khedr, S.M. Abd el Haleem and A. Baraka, J. Electronal. Chem. 182 (1985) 157), according to the Onsager reciprocal relations. The deviation observed at higher concentrations, independent of the cation nature, is attributed to concentration polarization and/or excessive water transport encountered in electroosmosis measurements.Determination of additional phenomenological coefficients of the same system, the hydraulic permeability and the electric resistance enabled the estimation of the effective exchange capacity of modified cellulose acetate membranes. The resulting value of 2.1×10?3 mol of unit charge/1 of pore liquid is compared to the corresponding values previously reported on a different basis. 相似文献