The Synthesis of yttrium oxide nanoparticles have been achieved via calcination
of yttrium hydroxide produced from the reaction of aqueous solutions of yttrium
nitrate and sodium hydroxide at pH = 13 using hydrothermal and hydrothermal
microwave methods. Effect of heat treatment of the resulted yttrium hydroxide
powder on the morphology and crystallinity of the resulting oxide was studied at
calcination 500, 700 and 1000°C to obtain. The resulted products were
characterized by means of X-ray diffraction (XRD), scanning electron microscope
(SEM), atomic force microscope (AFM), Fourier transform infrared spectrometer
(FTIR) and thermal analyses (TG).
Leucine amino peptidases (LAP; EC 3.4.11.1) constitute a diverse set of exopeptidases that catalyze the hydrolysis of leucine residues from the amino-terminal of protein or peptide substrates, (LAP) are present in animals, plants, and microbes. In this study, leucine amino peptidase was purified partial from Arachis hypogaea seeds by using gel filtration chromatography Sephadex G-100. The enzyme was purified 3.965 fold with a recovery of 29.4%. Its pH and temperature optimum were(8.7) and (37oC), respectively. The results show novel properties of LAP from Arachis hypogaea L. or peanut. The Km value for LAP (77 mM), with V max (1538 m mole min-1). We recommend a separate isoenzymeof the enzyme (LAP) from Arachis hypogaea on L. peanut seeds a
... Show MoreBeta-lactamase was purified from local isolate Klebsiella pneumonia by several steps included precipitation with ammonium sulphate at 20-40% saturation, DEAE- ion exchange chromatography and gel filtration on Sephacryl S-200 column. The obtained purification fold and recovery were 32.66; 47.04% respectively. The characterization of the purified beta-lactamase showed that the molecular weight was about 4000 daltons as determined by gel filtration.Purified enzyme had an optimal pH of 7 for activity and an optimal stability between pH 6.5-7.5, results shows that the optimal temperature appear to be 35 ? C .During storage the enzyme retained 72% at -20 ? C and retained 25% of the activity at the same period at 4 ? C.
Objective: Synthesis, Characterization of formazan derivatives and studies the antioxidant activity of prepared compounds and molecular docking. Methods: In this study, formazan compounds (III–XIV) were produced by combining Schiff base compounds (I), (II) with diazonium salts resulting from reactions of different aromatic amines with sodium nitrate in the presence of Con.HCl at 0–5°C. When isonicotinic acid hydrazide reacts with (N,N-dimethylbenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde) in the presence glacial acetic acid as a solvent Schiff base compounds are created. Results: The prepared compounds were identified by FT-IR, 1H NMR, 13C NMR, then the antioxidant activity of the derivatives and molecular docking were studied. D
... Show MoreEighty one bacterial isolates were obtained from 53 soil samples of different plants rhizosphere. All the isolated bacterial were screened for antifungal effect against Fusarium oxysporum . Three isolates gave antifungal activity with inhibition zone ranged between (0.5-2.5 cm). Two isolates (Bd1 and Bd2) were Brevundimonas diminuta, while the third (Pf1) was Pseudomonas fluorescence . B. diminuta (Bd1) which used in this study isolated from Raphanus sativus gave the highest inhibition zone against F. oxysporum. Cell free supernatant of B.diminuta(Bd1) was better in antifungal activity than bacterial cells against F. oxysporum. The highest antifungal substance production was obtained from mineral salt broth containing 1% peptone after in
... Show MoreThe molecular structures of acetophenonylidine-4-aminopyridine (I), 2, 6-dihydroxyacetophenonlidine-4-aminopyridine (II), 2, 4, 6- trihydroxyaceto phenonylidine-4-aminopyridine (III) and 2, 6-dihydroxyacetophenonylidine-2-aminopyridine (IV) have been investigated by IR and UV-visible spectrophotometry. The IR data indicate that the hydroxyl groups of these Schiff bases exist as tautomeric mixtures of free and bonded with the azomethine groups. The electronic spectra, effect of polar and nonpolar solvents, and the effect of acidity and basicity on the electronic spectra were studied and discussed. Their charge-transfer (CT) complexes with chloranil in chloroform solvent were also investigated; these complexes absorb light at 398-533 nm. T
... Show MoreIn this study, different methods were used for estimating location parameter and scale parameter for extreme value distribution, such as maximum likelihood estimation (MLE) , method of moment estimation (ME),and approximation estimators based on percentiles which is called white method in estimation, as the extreme value distribution is one of exponential distributions. Least squares estimation (OLS) was used, weighted least squares estimation (WLS), ridge regression estimation (Rig), and adjusted ridge regression estimation (ARig) were used. Two parameters for expected value to the percentile as estimation for distribution f
... Show MoreAbstract
This work is considered the first study for the components of the Iraqi Leucaena leucocephala plant, where the different phytochemical compounds that present in the aerial parts were identified by using the gas chromatography/mass spectrometry technique (GC/MS). The type of the components and their concentration will differ according to the part of the plant used and the method of extraction (hot and cold). This study made a comparison in lupeol concentration that was identified and isolated from petroleum ether fractions of Leucaena leucocephala by using Gas Chromatography/Mass Spectrometry (GC/MS), High-performance thin-layer chromatography (HPTLC), and Preparative High-Performance Li
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