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81.
Isolation,identification, and keratinolytic activity of several feather-degrading bacterial isolates
Several feather-degrading bacterial isolates were isolated from Egyptian soil. These isolates were able to degrade chicken
feather, when grown on basal medium containing 1% native feather as a source of energy, carbon, and nitrogen. Feather waste,
generated in large quantities as a byproduct of commercial poultry processing, is nearly pure keratin, which is not easily
degradable by common proteolytic enzymes. The isolates were identified according to the morphological characteristics, biochemical
tests, and API 50 CHBBacillus system. Proteolytic and keratinolytic activities of these isolates were monitored throughout the cultivation of the bacterial
isolates on feather. Resulting soluble proteins, which were released as a result of the biodegradation of feather, were demonstrated
by SDS-PAGE. 相似文献
82.
The study of the oxidation of low density polyethylene is carried out under fluidized conditions in air and ozone. Special attention is paid to the formation of peroxides and hydroperoxides. Their production is optimized according to various parameters (temperature, time, quantity of ozone, flow of the gaseous current) using an experimental design method. Peroxides and hydroperoxides are titrated by a colorimetric method using diphenylpicrylhydrazyl as reagent. A correlation between i.r. carbonyl ratio and the yield of peroxides has been established. 相似文献
83.
84.
M. M. Ghorab N. M. H. Taha M. A. A. Radwan N. E. Amin M. A. Shehab I. M. I. Faker 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2891-2905
This article describes the synthesis of some novel sulfone bis-compounds bearing the biologically active thioether 3–6 ; thioureido 7, 8, 15, 16; triazole 10, 11; thiosemicarbazido 9, 12, 13; and 1,3,4-thiadiazole 14, 17 moieties starting with 4,4′-diisothiocyanato-1,1-diphenylsulfone 2. The structures of newly synthesized compounds were confirmed by elemental analysis, IR, 1 H-NMR and mass spectral data. Compound 3 was found to be the most active compound against Escherichia coli. Also, compound 15 acted as potent cytotoxic agent. 相似文献
85.
Shih‐Sheng Wang Yu‐Hui Chen Jiun‐Yang Chang Tsong‐Long Hwang Chung‐Hsiung Chen Ashraf Taha Khalil Ya‐Ching Shen 《Helvetica chimica acta》2009,92(10):2092-2100
Chemical investigation of the Taiwanese gorgonian coral Junceella juncea resulted in the isolation of four new briarane‐type diterpenoids, juncenolides H, I, J, and K ( 1 – 4 ). Their structures were determined on the basis of spectroscopic analysis, especially 1‐ and 2D‐NMR. The inhibitory effects of compounds 1 – 4 on superoxide‐anion generation and elastase release by human neutrophils were evaluated. 相似文献
86.
Khalifa N. M. Haiba M. E. Taha M. M. Al-Omar M. A. 《Russian Journal of General Chemistry》2019,89(2):319-323
Russian Journal of General Chemistry - Novel polycyclic compounds, 1-pyrene-based pyridone derivatives, are synthesized by treatment of pyrenyl acetohydtazide with several arylidenemalononitriles... 相似文献
87.
Rare-earth elements (REEs) as Tm+3, Er+3, Yb+3 and Nd+3 have a significant optical photon emission. Therefore, Films of PMMA doped with 5?wt.% of NdCl3, TmCl3, ErCl3 or YbCl3 were prepared using the casting technique. FTIR of the prepared films has been studied. The optical and dispersion behavior of all doped samples have been investigated. The reflectance (R) and the transmittance (T) were measured in the wavelength range of 200–2500?nm. FTIR of all PMMA reveals that, REEs addition to PMMA samples creates new transmission peaks C=O groups and a decrease in the intensity of the absorption band of C–O groups has been obtained. The results showed the dependency of the refractive index and energy gap on the REE electronic transitions nature. The obtained results suggest strongly the applicability of these PMMA derivatives in improving the performance of the polymer optical fiber (POF). 相似文献
88.
Ahmed A. Taha 《国际化学动力学杂志》2012,44(8):514-523
The objective of this study is to test the suitability of the extended Hammett–Brown equation, log (kXX/kHH) = ρ+Σσ+, in depicting satisfactorily additive effects of electronegative atom‐bearing substituents, which are known to possess diverse and multicomponent influences on the side chain reactions of polysubstituted benzenes. The equation has been used to correlate, for the first time, the additive effect of substituents in the specific rates of solvolysis of 2‐chloro‐2‐phenylpropanes ( 3b–3f ) having 3‐F,4‐Me, 3‐Br,4‐Me, 3‐I,4‐Me, 3‐Me,4‐Me, or 3‐MeO,4‐Me substituents. The rates were determined titrimetrically at 288, 298, and 308 K using 90% aqueous acetone as solvent. Measured additive effects of these substituents on the solvolysis rate and activation parameters of the parent cumyl chloride (2‐chloro‐2‐phenylpropane) are found to be well correlated using the equation given above. Plots of log (kXX/kHH) of 3b–3f together with mainly di‐, but also tri‐ and mono‐substituted cumyl chlorides from previous studies against Σσ+ give a linear correlation coefficient of 0.990 as a measure of the validity of the equation to depict such systems. The halogen substituents' extent of conformity with additivity reflected in their relative (kobsd/kcalcd) rate ratios is found to correlate with the steric size of substituents. Plots of rate ratios against Taft's steric factor of each halogen give a linear correlation coefficient of 0.994 for the 3‐halo substituents. The 3,4‐dimethyl substituents' relative rate ratio of 1.03 shows excellent additivity, whereas the 3‐methoxy‐4‐methyl ratio of 1.43 shows the methoxy group to be far less deactivating than predicted. Similar trends were found for the free energy of activation (ΔG? – ΔG0?) differences, which correlated linearly with a coefficient of 0.983 with Taft's steric factor of halogen atoms. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 514–523, 2012 相似文献
89.
90.
Taha Sochi 《Central European Journal of Physics》2014,12(8):532-540
In this paper we investigate the yield condition in the mobilization of yield-stress materials in distensible tubes. We discuss the two possibilities for modeling the yield-stress materials prior to yield: solid-like materials and highly-viscous fluids and identify the logical consequences of these two approaches on the yield condition. Our results reveal that these two modeling approaches have far reaching consequences on the yield bottleneck and hence should be critically examined in the light of experimental evidence. As part of this investigation we derive an analytical expression for the pressure field inside a distensible tube with a Newtonian flow using a one-dimensional Navier-Stokes flow model in conjunction with a pressurearea constitutive relation based on elastic tube wall characteristics. This analytical expression has wider applicability than in the identification of the yield condition of yield-stress material. 相似文献