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Search Results: 1 - 10 of 13701 matches for " Magdy Ahmed Ibrahim "
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Synthesis and characterization of new chromeno[2,3-b]pyridines via the Friedl nder reactions of 8-allyl-2-amino-4-oxo-4H-chromene-3-carboxaldehyde
Magdy Ahmed Mohamed Ibrahim
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.2.124-128.75
Abstract: New series of chromeno[2,3-b]pyridines, 2-8, have been obtained from 1,8-diazabicyclo [5.4.0]undec-7-ene catalyzed Friedl nder reaction of 8-allyl-2-aminochromone-3-carboxaldehyde (1) with some carbonyl compounds containing a reactive α-methyl or methylene group namely 2-acetylthiophene, 3-acetylpyridine, 4-chloroacetophenone, 4,6-diacetylresorcinol, acetylacetone, dibenzoyl methane and acetoacetanilide. Heteroannulated chromones, 13-16, were prepared from Friedl nder reaction of 1 with some cyclic α-methylene ketones namely 2-phenyliminothiazolidin-4-one, pyrazoline-3,5-dione, 5,5-dimethylcyclohexane-1,3-dione and thiobarbituric acid. Structures of the newly synthesized compounds have been established from elemental analysis and spectroscopic data.
Utilization of Trimethylolpropane Based Hyperbranched Poly(Amine-Ester) as New Polymeric Admixture  [PDF]
Amal Amin Ibrahim, Ahmed El-Sayed Abdel-Magied, Mohamed Sayed Selim, Magdy Mohamed Hussein Ayoub
Open Journal of Organic Polymer Materials (OJOPM) , 2012, DOI: 10.4236/ojopm.2012.22004
Abstract: Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared polymer was analyzed by IR, GPC, 1H-NMR and thermal analysis (TGA and DSC). The performance of the polymer in cement was tested by measuring the effect of 1, 3 and 5 wt% of HBPAE solutions on the properties of Ordinary Portland Cement. Water of consistency, setting times, bulk density, apparent porosity, compressive strength and combined water content of the polymer/cement pastes were studied. The results showed that water of consistency and apparent porosity decreased while setting times, compressive strength, combined water and bulk density increased with the polymer addition.
Synthesis and antimicrobial activity of chromone-linked 2-pyridone fused with 1,2,4-triazoles, 1,2,4-triazines and 1,2,4-triazepines ring systems
Ali, Tarik El-Sayed;Ibrahim, Magdy Ahmed;
Journal of the Brazilian Chemical Society , 2010, DOI: 10.1590/S0103-50532010000600010
Abstract: three series of novel fused nitrogen heterocyclic systems such as 1,2,4-triazolo[1,5-α ] pyridines (5-7 and 9), pyrido[1,2-b][1,2,4]triazines (10, 11, 13 and 15), and pyrido[1,2-b][1,2,4]triazepines (17, 18, 20 and 22) linked with a chromone moiety were synthesized from the key intermediate 1,6-diamino-(6-chloro-4-oxo-4h-chromen-3-yl)-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile (4) with some electrophilic reagents. the structures of the novel compounds were established by elemental analyses and spectral data. all the products were also screened invitro for their antimicrobial activity. compounds 7, 9 and 15 showed the highest activities when compared with the reference drugs.
Online Signature Verification: State of the art
Ibrahim El-Henawy,Magdy Rashad,Omima Nomir,Kareem Ahmed
International Journal of Computers & Technology , 2013,
Abstract: online or Dynamic signature verification (DSV) is one of the most acceptable, intuitive, fast and cost effective tool for user authentication. DSV uses some dynamics like speed, pressure, directions, stroke length and pen-ups/pen-downs to verify the signer's identity. The state of the art in DSV is presented in this paper. several approaches for DSV are compared and the most influential techniques in this field are highlighted. We concentrate on the relationship between the verification approach used (the nature of the classifier) and the type of features that are used to represent the signature.
A new approach for the synthesis of bioactive heteroaryl thiazolidine-2,4-diones
Ibrahim, Magdy Ahmed;Abdel-Hamed, Mohamed Abdel-Megid;El-Gohary, Naser Mohamed;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000600019
Abstract: condensation of 3-formylchromone (1) with thiazolidine-2,4-dione (2) afforded 5-[4-oxo-4h-chromen-3-yl)methylene]-1,3-thiazolidine-2,4-dione (3). reaction of 3 with hydrazine hydrate, phenyl hydrazine and hydroxylamine hydrochloride gave the corresponding pyrazole and isoxazole derivatives 4-7. compound 3 was subjected to react with thiourea, guanidine and cyanoguanidine to give the corresponding pyrimidine derivatives 8-10. pyrimido[1,2-a]pyrimidine 12, benzo[1,5]diazepine 15, pyrido[1,2-b][1,2,4]triazepine 16, 1,2,4-triazolo[3,4-b][1,3,4]thiadiazepine 19 and 1,2,4-triazino[3,2-b][1,3,4]thiadiazepine 20 linked thiazolidine-2,4-dione were prepared from the reaction of 3 with n,n- and n,s- bifunctional nucleophiles. the chemical reactivity of 3 towards carbon nucleophiles gave new heterocyclic moieties linked thiazolidine-2,4-dione 22?25. the synthesized compounds were screened in vitro for their antimicrobial activities against staphylococcus aureus, proteus vulgaris and candida albicans.
Colorectal carcinoma in gharbiah district, Egypt: Comparison between the elderly and non-elderly
Ahmed Abdelmabood Zeeneldin,Magdy M Saber,Ibrahim Seif El-din,Sara A Farag
Journal of Solid Tumors , 2012, DOI: 10.5430/jst.v2n3p13
Abstract: Objective: This work was conducted to study colorectal carcinoma (CRC) in Gharbiah district, Egypt and to verify the effect of age on the treatments and their outcomes. Methods: Between 2000 and 2002, 293 cases with CRC were identified in the Gharbiah population based cancer registry (GPBCR); 159 of whom were treated at Tanta Cancer Center (TCC). Patients were grouped into elderly and non-elderly (≥ and < 65 years, respectively). Results: CRC was the 6th cancer in Egypt, representing 4% of the total cancers and 53% of GIT cancers. The median age was 53 years with male predominance. Colon cancers were more common than rectal cancers. Most patients had tumors that were localized, low grade and adenocarcinoma (AC). Constipation, abdominal pains and bleeding per rectum were the commonest complaints. Surgery, radiotherapy and chemotherapy were adopted in 84, 28 and 72% of patients, respectively. The median OS and PFS were 23 and 25 months (95%CI: 17-29 and 11.8-18.2), respectively. Compared to non-elderly, elderly patients were more likely to have rectal tumors, non-AC histology, non-metastatic disease; more comorbidities were less likely to receive chemotherapy particularly in the adjuvant setting (P< 0.05 for all). The OS and PFS of elderly patients were not statistically different from the non-elderly. Conclusions: Within the limits of this retrospective trial, elderly patients with CRC tend to have more rectal and non-metastatic cancers. They were more likely to have comorbidities and less likely to receive chemotherapy. However, the OS and DFS were comparable to non-elderly.
Novel heterocyclic derivatives of pyrano[3,2-c]quinolinone from 3-(1-ethy1-4-hydroxy-2-oxo-2(1H)-quinolin-3-yl)-3-oxopropanoic acid
Magdy Ahmed Ibrahim,Hany Mohamed Hassanin,Yassin Abdel-Allah Gabr,Youssef Abdel-Salam Alnamer
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.3.195-199.91
Abstract: 3-(1-Ethyl-4-hydroxy-2-oxo-2(1H)-quinolin-3-yl)-3-oxopropanoic acid (2) has been synthesized. The chemical behaviour of β-ketoacid 2 was studied towards condensation reactions with salicylaldelyde, 2-hydroxy-1-naphthaldehyde, 1-phenyl-4-hydroxy-2-oxo-quinoline-3-carboxaldehyde, 2-hydroxy-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxalde-hyde, 2-amino-3-formylchromone and its 8-allyl analog, 3-cyanochromone and its 8-allyl analog. Structures of the newly synthesized products have been deduced from their elemental analysis and spectral data.
1,2,4-Triazine Chemistry Part II: Synthetic approaches for phosphorus containing 1,2,4-triazine derivatives
Reda Mohammady Abdel-Rahman,Magdy Ahmed Ibrahim,Tarik El-Sayed Ali
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.4.388-396.154
Abstract: This review represents the methods developed for the synthesis of phosphorus containing 1,2,4-triazine moieties. These methods depends on the phosphorylation of side functional groups of 1,2,4-triazines and cyclization of side functional groups of 1,2,4-triazines with phosphorus reagents to give isolated and fused phosphorus heterocyclic systems.
Efeito do NaCI sobre o crecimento ea multiplica??o in vitro de bananeira
Macêdo, Cristiane Elizabeth Costa de;Barroso, Paulo Augusto Vianna;Moura, Gioconda Emanuella Diniz de Dantas;Alloufa, Magdy Ahmed Ibrahim;
Revista Brasileira de Fruticultura , 2005, DOI: 10.1590/S0100-29452005000200003
Abstract: soil salinity is an important factor of stress that occurs in many semi-arid and arid regions of brazil where the bananeira is cultivated. the effect of different sodium chloride (nacl) concentrations, in vitro, on the growth and shoot multiplication derived from explants of "grand naine" variety was studied. the shoot-tips of the bananeira were inoculated in ms media in the absence: t0=0 (control) and in the presence of three nacl treatments: t1=50mm, t2=75mm e t3=100mm and sub cultured five times in the respective treatments. the subcultures were carried out every 30 days and the number of shoots multiplicated on each inoculated shoot, length and total number leaves of inoculated shoot and production of fresh weight were observed at 0; 30; 60; 90; 120 e 150 days after salt exposition. the results showed that the presence of nacl in the media affects the shoot's production in vitro. the increase of nacl concentration in the media is proportional to the decrease in the number of shoots produced. the multiplication of bananeira's shoot reduced about 80% in the treatment t1, while the treatments t2 and t3 achieved 90% of reduction. on the other hand the two saline treatments 75 and 100 mm interfered at the same form in the growth of shoots, production of fresh weight, length and total number of leaves. under experimental conditions the best dose among the different sodium chloride was 50 mm because this dose showed intermediary effects on the characters evaluated.
Revista Brasileira de Fruticultura , 2001, DOI: 10.1590/S0100-29452001000200043
Abstract: culture media studies that facilitate recalcitrant seed germination are very important to the fruit crops. mangabeira (hancornia speciosa gomez) is a native specie from brazilian northeast. its propagation by traditional methods is difficult because its seeds are recalcitrant and the fruit pulp has an inhibitory effect on seed germination. trying to maximize its in vitro germination percentage, it was tested the influence of sucrose (0; 10; 30; 60 e 90 g/l), giberelic acid (0; 0.1; 0.3 e 0.5 mg/l), and different culture media (distilled water, coconut water, solid ms and liquid ms). it was also tested the scarification effects (seeds with or without tegument). the seeds obtained from mature fruits were scarified or not and inoculated in media containing different treatments. the germination rate was calculated 30 days after the seed inoculation. seeds without tegument obtained higher germination percentage in all studied culture media being the highest one obtained from ms liquid treatment. the exclusion of sucrose favored the germination in ms solid medium as well in ms liquid. the highest seed germination percentage in ms supplemented with giberelic acid, in both ms solid and ms liquid media, occurred at 0.1 mg/l concentration. the highest in vitro germination rates were obtained upon removal of the seed tegument and posterior inoculation in ms liquid medium supplemented by 0.1 mg/l of giberelic acid.
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