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1.
This paper is based on the M. Sc. thesis written by the third author under the supervision of the first two authors. It was submitted to the University of Baghdad in 1986. 相似文献
2.
Maged H. M. Sharaf Paul L. Schiff Albert N. Tackie Charles H. Phoebe Robert L. Johnson Doug Minick Ronald C. Crouch Gary E. Martin C. Webster Andrews 《Journal of heterocyclic chemistry》1996,33(3):789-797
The isolation and structure determination of cryptomisrine, a novel indolo[3,2-b]quinoline dimeric alkaloid obtained from extracts of the roots of the Ghanaian medicinal plant Cryptolepis sanguinolenta is reported. The structure determination was made via a consideration of the spectral data, including uv, ir, nmr, and mass spectra. In particular, one-dimensional proton/carbon nmr, one-dimensional nOe difference nmr, and a series of homonuclear (COSY) and inverse-detected heteronuclear two-dimensional (HMQC, HMBC) experiments were utilized, as well as high resolution FABMS. Cryptomisrine is most unusual in that its two monomeric parts apparently exist in such a C2 symmetric environment that only one set of proton and carbon nmr resonances are observed. Cryptomisrine is the first example of a dimeric indolo-[3,2-b]quinoline alkaloid to have been isolated from nature. 相似文献
3.
N. A. Sharaf F. M. Ezz-Eldin A. A. Ahmed 《Journal of Radioanalytical and Nuclear Chemistry》1994,183(2):205-217
Absorption bands in the range of 350–950 nm, induced in copper-containing lead borate glasses by -rays were identified and characterized. The effect of irradiation dose, copper oxide and lead oxide contents on the intensity and position of the induced absorption bands were also considered. Several induced absorption bands were observed. At least two bands in the ranges of 740–780 and 850–870 nm could be identified. They are suggested to be associated with induced Cu(2+) ions. The band in the 800–830 nm (1.6 eV) range is ascribed to the Pb(3+) ion, whereas others in the ranges of 600–630 and 650–730 nm are associated with the intrinsic defects formed in the base glass. 相似文献
4.
Ronald C. Crouch Ann O. Davis Timothy D. Spitzer Gary E. Martin Maged M. H. Sharaf Paul L. Schiff Charles H. Phoebe Albert N. Tackie 《Journal of heterocyclic chemistry》1995,32(3):1077-1080
Elucidation of minor natural product structures has been significantly augmented by inverse-detection; further improvement has been afforded by the development of micro inverse-detection probes. We report here the elucidation of the structure of a new alkaloid, quindolinone (5H, 10H-indolo[3,2-b]quinolin-11-one), from the West African plant Cryptolepis sanguinolenta. All nmr data for this minor, preparative hplc-isolated alkaloid, including 1H-15N one? bond heteronuclear shift correlation (HMQC) data, were recorded on an 800 μg sample of the alkaloid dissolved in 140 μl of 100% d6-DMSO using a 400 MHz spectrometer. 相似文献
5.
N. M. Spyrou J. M. Sharaf S. Rajeswaran E. Mesbahi 《Journal of Radioanalytical and Nuclear Chemistry》1997,217(2):237-241
The factors that affect accurate, quantitative results to be obtained by neutron induced gamma-ray emission tomography are stated. The technique, which is a combination of neutron activation analysis with computerised gamma-ray emission tomography, would be enhanced by the use of multiple detector assemblies, in geometrical configurations, which simultaneously record the gamma-rays emitted and improve detection efficiency. Developments in the past few years in positron emission tomography (PET) where scanners made of single scintillation block detectors, cut into smaller segments, to form individual crystal detector elements and packed in ring around the radioactive object, are discussed. The coincident detection efficiency for annihilation photons and cascade gamma-rays for such systems are considered and the possibilities of carrying out NIGET with coincident gamma-ray tomography are explored whilst indicating some of the limitations. This is an area which requires further, intense investigation and has an impact on a wide range of applications, particularly in the biomedical field. 相似文献
6.
M.A. Shams El-Din M. KoerdtC. Wochnowski F. VollertsenA.M. Sadik 《Optics and Lasers in Engineering》2012,50(3):405-412
Polymeric integrated-optical waveguides are prepared in a planar polymer chip by UV-laser lithographic methods. The waveguide samples are irradiated by an excimer laser at a wavelength Λ=248 nm with various irradiation parameters (different fluencies and irradiation doses). Mach-Zehnder interferometer is employed and the refractive index depth profiles of the waveguide samples are obtained. This profile covers two regions having exponential and Gaussian shapes. The model field distributions strongly depend on the refractive index of each region. The mode field distribution and the effective mode indices for each region have been calculated on the basis of a theoretical model and the experimentally measured data. 相似文献
7.
E. H. Borai I. M. Ahmed A. M. Shahr El-Din M. S. Abd El-Ghany 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(2):443-450
The present work succeeded to develop new optional procedures to enhance the separation process of thorium and REEs. Selective precipitation of thorium with pyrophosphate was successfully attained for the upscale level in which, complete and efficient thorium separation (99%) was achieved with relatively low co-precipitation of REEs (average 15%) and Fe(III) (2.6%). On the other hand, promising and costless method has been developed to optimize the selective precipitation of REEs by adjusting the ratio of the free acids H2SO4 to H3PO4 at 5:1. It could be obviously demonstrated that about 65.3% of LREEs could be precipitated with a minor amount of thorium 11.9%. Finally, this proposed method could be successfully applied for production of Th and REEs with relatively high yield and purity in addition to low-cost–benefit. 相似文献
8.
Hassan Talaat Ali H. Moussa M. Shalaby El-Wallid S. Sedik M. Tag El-Din Kamal 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(3):454-460
We apply the time-dependent theory to the collinear exchange reaction F + CH4 → FCH3 + H. We have performed detailed calculations on two-dimensional potential surfaces representing the ground electronic potentials of the collinear F + CH4 → FCH3 + H reaction, at incident energies. Transmission coefficients range from zero to unity, depending upon the incident energy. Normal modes of vibrations are displayed along the reaction path. 相似文献
9.
A. M. Al-Sabagh M. R. Noor El-Din H. M. Mohamed 《Journal of Dispersion Science and Technology》2013,34(7):1079-1090
Six oil soluble nonionic surfactants with different HLBs have been prepared. Their HLBs situate between 3.9 and 6.7. Transesterification was carried out for glycerol and triethanol amine with oleic acid at different moles to obtain six emusilifiers. They named glycerol momooleate (I), glycerol diooleate (II), glycerol trioleate (III), triethanol amine mono-, di- and tri-oleate (IV), (V,) and (VI). The chemical structure was confirmed using; the elemental analysis, FTIR and 1HNMR. They were evaluated as a primary emulsifiers (PE) for thdrilling fluids (oil base mud) comparing with a currently used primary emulsifier (Fc). The water in oil base mud (w/o emulsions) was prepared. The concentration of emulsifiers and their HLB exhibited interesting rheology properties including shear-thinning behavior, yield value, viscoelastic effects, thixtropy, gel strength, and filtration loss. The rheology properties of such emulsions strongly depended on the average size distribution of the dispersed droplets that could be varied both with the bulk concentration and HLB value of the emulsifiers. The interfacial and surface properties of these emulsifiers suggest that the droplet size of the dispersed phase and bulk concentration are strongly related to the HLB value of emulsifiers. The w/o emulsion (mud formulation) stability is sensitive to the droplet size of the dispersed phase and HLB value of the used emulsifier. The results were discussed on the light the chemical structure of the primary emulsifiers and the emulsion ingredients. 相似文献
10.
Ragaa A. Hamouda Mervat H. Hussein Noura El-Ahmady El-Naggar Mohammed A. Karim-Eldeen Khalid H. Alamer Muneera A. Saleh Luluah M. Al Masoudi Eman M. Sharaf Reham M. Abd El-Azeem 《Molecules (Basel, Switzerland)》2022,27(4)
Seaweeds can play a vital role in plant growth promotion. Two concentrations (5 and 10 mg/mL) of soluble polysaccharides extracted from the green macroalgae Ulva fasciata and Ulva lactuca were tested on Zea mays L. The carbohydrate and protein contents, and antioxidant activities (phenols, ascorbic, peroxidase, and catalase) were measured, as well as the protein banding patterns. The soluble polysaccharides at 5 mg/mL had the greatest effect on the base of all of the parameters. The highest effects of soluble polysaccharides on the Zea mays were 38.453, 96.76, 4, 835, 1.658, 7.462, and 38615.19, mg/mL for carbohydrates, proteins, phenol, µg ascorbic/mL, mg peroxidase/g dry tissue, and units/g tissue of catalase, respectively. The total number of protein bands (as determined by SDS PAGE) was not changed, but the density of the bands was correlated to the treatments. The highest band density and promoting effect were correlated to 5 mg/mL soluble polysaccharide treatments extracted from Ulva fasciata in Zea mays, which can be used as a biofertilizer. 相似文献