296 research outputs found

    Reinvestigation of the Reaction of Phenacy lMalononitrile with Hydrazines under Solvent Conditions

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    Phenacylmalononitrile 3 reacts with hydrazine hydrate in refluxing dioxan to afford the iminopyridazine derivative 6 and the pyrazolo[3,4-c]pyridazine derivative 7.Compound 3 reacts also with phenylhydrazine in refluxing ethanol to afford the iminopyridazine derivative 11 along with the phenylhydrazone derivative 12. Compound 12 could be cyclized into the pyrazolo[3,4-c]pyridazine derivative 13 upon reflux with sodium ethoxide

    Preparation and spectroscopic studies of Hydroxyapatite embedded in Poly(N-Vinylpyrrolidone) matrix

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    Pure HAp powder was prepared by precipitation and HAp/PVP composites were prepared by casting technique. X-ray diffraction was performed to examine the crystallinity and the complexation between HAp and PVP when the amount of HAp increased. XRD and EDX analysis showed that the concentration 15 wt% is the most confirmation for the formation of HAp. SEM shows more than one form of HAp such as plates, needles and bundles in the morphological structure of pure HAp and 15 wt% of HAp. Two main weight loss regions and two peaks were observed in TGA and DSC thermograms that reveal reduction in the thermal stability of the prepared samples as HAp content increases. The activation energy of the films was decreased with increasing the concentration of HAp. DSC thermographs of the samples show that the values of the glass transition temperatures are decreased with increasing the content of HAp filler which suggest that HAp filler act as plasticizer. The conductivity–temperature plots show linear variation, which suggests an Arrhenius behavior. The conductivity increases with adding HAp content for low concentrations while decreased for the critical concentration (15 wt %) which confirms the XRD results

    Is unilateral varicocelectomy as effective as bilateral varicocelectomy in management of subfertile patients with bilateral varicocele

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    Objectives: To compare the results of unilateral and bilateral subinguinal varicocelectomy for patients with primary infertility, including sperm parameters and pregnancy rate.Patients and method: This a retrospective study including 91 men with primary subfertility with bilateral varicocelectomy. The patients were divided into two groups. Group A (46 patients) were subjected to bilateral varicocelectomy. Group B (45 patients) subjected to left varicocelectomy. Patients with unilateral, recurrent, subclinical, secondary varicocele and azoospermia were excluded. All Patients were evaluated with at least two semen analyses with 15 days apart. Follow up schedule for all patients includes physical examination and semen analysis 3, 6, and 12 months postoperatively.Results: Subinguinal varicocelectomy with loup magnification was successfully performed in all 91 patients, with no intra-operative complications occurred. The age ranged between 25 and 39 years (average 32 years),which was not significantly different within the 2 groups. The mean follow up was 7 months. Neither definite hydrocele nor testicular atrophy was detected. Despite considerable changes were noted in sperm concentration, percentage of motility and normal sperm morphology postvaricocelectomy in both groups, there was not a statistically significant difference between the two groups, (P = 0.139, 0.922, and 0.825, respectively and also pregnancy rate (P = 0.14).Concolusions: The semen parameters and pregnancy rate improved significantly in patients who underwent unilateral and bilateral varicocelectomy, with no significant difference between the two groups

    Synthesis and optimization of Novel Chitosan/Cellulose Acetate Natural Polymer Membrane for water treatment

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    Chitosan (Ch) and Cellulose Acetate (CA) natural polymer in addition to other samples with different mass fractions of Chitosan/Cellulose Acetate (Ch/CA) were synthesized via simple casting route. Prepared samples were studied using FT-IR and UV/vis spectroscopic techniques. Structural variations due to the process of blending were retraced using X-ray diffraction data (XRD) and morphological investigation using scanning electron microscopy (SEM). Obtained spectral data reveals compatibility and complexation between polymer constituents identified through presence of polymer characteristic peaks with small variation in both intensity and position along with change in the value of optical energy gap from UV optical absorption spectral data. XRD pattern indicate the semicrystalline nature of the studied sample with an observable change in the crystallinity. Moreover, scanning electron microscopic (SEM) micrographs reveals homogenous structure without any evidence for agglomerations nearly in all compositions

    Synthesis and Molluscicidal Activity of Some Newly Substituted Chromene and Pyrano[2,3-c]pyrazole Derivatives

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    The arylidene derivatives 3a-f react with 1,3-cyclohexanedioneand dimedone 4a,b to afford the 4-(2- or 3-pyridyl) or 4-pipronyl-chromene derivatives 6a-l. The arylidene derivatives 3a-c react with the pyrazolone derivatives 7a,b to afford the pyrano[2,3-c]pyrazole derivatives 9af.The molluscicidal activity of the synthesized compounds towards Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni, was investigated and most of them showed weak to moderate activity.

    Heterocyclic synthesis with ω-bromoacetophenone: Synthesis of some new pyrazole, pyridazine and furan derivatives

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    p-Bromophenacylnitrile derivatives 3a,b react with hydrazinederivatives under different conditions to afford the diaminopyrazoles 4a,b, the pyridazine-6-imines 5a,b,and 5-aminopyrazoles 11a,b. Refluxing of 5a in ethanol/hydrochloric acid mixture furnished its transformation into the pyridazine-6-one 6 while 5b under the same reaction conditions, underwent ring contraction expelling phenyl hydrazine to afford the furan derivative 7.Compound 7 could also be obtained from 3a upon refluxin ethanol catalyzed by triethylamine. Ethyl  phenacylcyanoacetate 3b reacts with hydrazine hydrate and phenylhydrazine to afford the 4-phenacylpyrazole derivatives11a,b respectively. Compound 3b afforded a mixture ofthe two furan derivatives 12 and 13 upon reflux in ethanolcatalyzed by triethylamine. Compound 3b also undergoesthe coupling reaction with the aromatic diazoniumsalts 14a-d to afford the pyrazole derivatives 16a-d presumablyvia the hydrazo derivatives 15a-d respectively
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