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211.
Kadhim Kh. Hashim Shatha Y. Yahyaa Asmaa A. Mohmmed Al-Rashidy 《Journal of fluorescence》2018,28(6):1275-1280
The determination of the fluorescence quantum yield of Propylparaben is introduced and applied to L-tyrosine as a standard by a new approach that can be applied to the pharmaceutical compound utilised in this study. The quantum yield is a critical figure of quality for the optical nature of a fluorophore. Numerous investigations have considered the glitter in both pharmaceutical and nature compounds for its medical and industrial significance. A straightforward method is detailed here to decide the quantum yield of Propylparaben in solution as an element of the fluorescence concentration. For this reason, L-Tyrosine is chosen as a fluorescence standard perspective to gauge the Propylparaben fluorescence quantum yield. The impacts of pH, solvents and flow rate on the assessment of quantum yield and quantum efficiency, for the reference and the solutions of Propylparaben, have been investigated. The results indicated that these parameters significantly influence the accuracy of the method. Diverse methods are concentrated on to represent distinctive quantum yield advancements with the quantum efficiency. The impact of these parameters was likewise considered. In this study, the application of the single method may be taken into consideration to compute quantum yield of Propylparaben, which was 0.36, and this is an exceptionally basic and general technique to solve the imperative issue of luminescence quantum yield assurance of other fluorescence compounds. 相似文献
212.
5‐Phenyl‐1,3,4‐oxadiazole‐2‐thiol/polyamide‐montmorillonite microbicides nanocomposites as drug delivery system
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Nehal Salahuddin Ahmed Elbarbary Nanis G. Allam Ayat F. Hashim 《Journal of Physical Organic Chemistry》2018,31(7)
The preparation and structural characterization of polymeric microbicides consisting of 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol covalently bound to polyamide based on diethyl‐2,3‐dihydroxysuccinate and polyoxypropylenetriamine Jeffamine (T403) are described. Two different mole ratios of 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol was reacted with chloroacetylated diethyl‐2,3‐dihydroxysuccinate followed by polycondensation with Jeffamine (T403). The nanocomposites were prepared by modification of microbicide polyamides to yield polymers with phosphonium salt or amine hydrochloride salt followed by ion exchange process between the phosphonium salt or amine hydrochloride of the polyamides and the intermellar sodium cation of the clay mineral montmorillonite. The monomers were characterized by mass spectrum, proton nuclear magnetic resonance. The polymers showed good or moderate antimicrobial activities. Nanocomposites were characterized by Fourier transformed infrared spectroscopy, X‐ray diffraction, thermal gravimetric analysis, and transmission electron microscope. The swelling behavior and release of 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol in different pH values (2.3, 5.8, and 7.4) were studied. A slow release, ranging from 12% to 28% after 50 hours was recorded from nanocomposites. However, the release profile reached almost 70% from polyamides. The antimicrobial activity of the polyamides was studied against gram‐negative bacteria, gram‐positive bacteria, yeast, and the filamentous fungi by well diffusion method. The polyamides showed better antimicrobial activities than 5‐phenyl‐1,3,4‐oxadiazole‐2‐thiol. 相似文献
213.
In this note we study an abstract class of weakly dissipative second-order systems with finite memory. We establish the polynomial decay of Rivera, Naso and Vegni for the solution of the system under a very weak condition on the relaxation function. 相似文献
214.
Ahmad Hussein Alomari Muneer Aziz Saleh Suhairul Hashim Amal Alsayaheen Ahmad Abukashabeh 《Isotopes in environmental and health studies》2019,55(2):211-226
An extensive study was conducted to determine the activity concentrations of natural and artificial radionuclides 226Ra, 232Th, 40K, and 137Cs in soil samples of each governate of Jordan. A total of 370 samples have been measured using a high-purity germanium detector. The activity concentration for 226Ra, 232Th, 40K, and 137Cs has mean values of 42?±?3, 23?±?3, 309?±?21, and 3.7?±?0.9 Bq kg–1, respectively. The highest mean activity concentration for 226Ra was found to be 138?±?4 Bq kg–1 in the Alkarak governate. In the Ajloun and Jarash governates, the highest mean activity concentration was 35?±?3 Bq kg–1 for 232Th, and 14.2?±?1.9 Bq kg–1 for 137Cs, respectively. Geological influence on the activity concentrations was investigated using the one-way analysis of variance (ANOVA) and independent samples. The ANOVA results indicate that there are strong significant differences between the activity concentrations of 232Th, 40K, and 137Cs based on geological formations the radionuclides occur. The main contribution to gamma dose rate was due to 226Ra activity concentration. Radium equivalent and external hazard index are associated with a mean value of 98 Bq kg–1, and 0.266, respectively. 相似文献
215.
Aberrant expression of acute-phase reactant proteins in sera and breast lesions of patients with malignant and benign breast tumors 总被引:3,自引:0,他引:3
We have analyzed unfractionated sera of newly diagnosed patients (n=10) with breast carcinoma (BC), prior to treatment, and patients (n=5) with fibrocystic disease of the breast (FDB) by two-dimensional gel electrophoresis (2-DE) and silver staining. The patients' 2-DE serum protein profiles obtained were then subjected to image analysis and compared to similar data generated from sera of normal healthy female controls (n=10) of the same range of age. The relative expression of alpha1-antichymotrypsin (ACT), clusterin, and complement factor B was significantly higher in all BC patients as compared to normal controls. However, the expression of alpha1-antitrypsin (AAT) in BC patients was apparently lower than that of the controls. Similar differential expression of ACT was detected in the FDB patients. The aberrant expression of the serum acute-phase proteins of patients with BC and FDB was confirmed by competitive enzyme-linked immunosorbent assay (ELISA). Similar altered proteins expression was also observed from immunohistochemical studies of malignant (n=5) and benign (n=5) breast lesions of the respective patients performed using antisera to the aberrantly expressed proteins. However, the malignant breast lesions were instead positively stained for AAT. The differential expression of the serum proteins was apparently abrogated when a six-month follow-up study was performed on nine of the BC patients subsequent to treatment. 相似文献
216.
Jumiah Hassan Farm Mooi Yen Mansor Hashim Zulkifly Abbas Zaidan Abdul Wahab W. Mohd. Daud W. Yusoff Azmi Zakaria 《Ionics》2007,13(4):219-222
NiFe2O4 prepared via the sol–gel technique were pre-sintered at 900 °C and synthesized at different sintering temperatures from 1,000 °C
to 1,200 °C at 100 °C intervals. The samples were characterized for microwave dielectric properties. These samples were measured
using Agilent Impedance/Material Analyzer at frequencies 1 MHz to 1.8 GHz. Results showed a decrease in the dielectric constant
and loss factor with frequency except at the turning point, around 150 MHz, where the loss factor showed a gradual increase.
However, both the dielectric constant and loss factor increase with increasing sintering temperature. The grain size and density
also increased with increasing sintering temperature, but the porosity and grain boundary density showed a decrease.
This paper was presented at the International Conference on Solid State Science and Technology 2006, Kuala Terengganu, Malaysia,
Sept. 4–6, 2006. 相似文献
217.
218.
The data on neutrino (antineutrino), neutral and charged current cross-sections and theiry-distributions are analysed within the framework of the Weinberg-Salam theory and the quark-parton model incorporating charm.
Other existing models are also compared. Interpretation of data appears easy in the case of models with charm whereas it is
not so if charm is absent. Under some reasonable assumptions, the numerical values of the first moments of parton distribution
functions are obtained. The sin2
ϑ
W
and other useful parameters are also determined for the various models. 相似文献
219.
The lithium sodium borate glasses doped with Eu3+ ion are prepared using melt quenching technique, their structural and optical properties have been evaluated. The density of prepared glasses exhibits an inverse behavior to the molar volume ranging from 2.26 g/cm3 to 2.43 g/cm3 and 26.95 cm3 /mol to 26.20 cm3 /mol, respectively. The absence of sharp peaks in XRD patterns confirms the amorphous nature of the prepared glasses. The absorption spectra yield four transitions centered at 391 nm (7F0→5L6), 463 nm (7F0→5D2), 531 nm (7F0→5D1), and 582 nm (7F0→5D0). The most intense red luminescence is observed at 612 nm corresponding to 5D0→7F2 transition under 390 nm laser excitations. 相似文献
220.
Enas E. Eltamany Usama Ramadan Abdelmohsen Dina M. Hal Amany K. Ibrahim Hashim A. Hassanean Reda F. A. Abdelhameed Tarek A. Temraz Dina Hajjar Arwa A. Makki Omnia Magdy Hendawy Asmaa M. AboulMagd Khayrya A. Youssif Gerhard Bringmann Safwat A. Ahmed 《Molecules (Basel, Switzerland)》2021,26(6)
Chemical investigation of the methanolic extract of the Red Sea cucumber Holothuria spinifera led to the isolation of a new cerebroside, holospiniferoside (1), together with thymidine (2), methyl-α-d-glucopyranoside (3), a new triacylglycerol (4), and cholesterol (5). Their chemical structures were established by NMR and mass spectrometric analysis, including gas chromatography–mass spectrometry (GC–MS) and high-resolution mass spectrometry (HRMS). All the isolated compounds are reported in this species for the first time. Moreover, compound 1 exhibited promising in vitro antiproliferative effect on the human breast cancer cell line (MCF-7) with IC50 of 20.6 µM compared to the IC50 of 15.3 µM for the drug cisplatin. To predict the possible mechanism underlying the cytotoxicity of compound 1, a docking study was performed to elucidate its binding interactions with the active site of the protein Mdm2–p53. Compound 1 displayed an apoptotic activity via strong interaction with the active site of the target protein. This study highlights the importance of marine natural products in the design of new anticancer agents. 相似文献