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51.
Undoped and transition metals (TM 3d)-doped lead phosphate glasses were prepared. Ultraviolet–visible absorption spectra were measured in the range 200–1100 nm before and after successive gamma irradiation. Experimental results indicate that the undoped lead phosphate glass reveals before irradiation strong and broad ultraviolet absorption which is related to the co-sharing of absorption due to both trace iron impurities and lead ions (Pb2+). In the TM-doped glasses, characteristic absorption bands are obtained in both the UV and/or visible regions due to each respective TM ion in addition to that observed by the base undoped UV absorption. Gamma irradiation produces with the undoped glass a prominent induced ultraviolet broad band centered at about 300 nm originating mostly from the contribution of trace iron impurities and the visible spectra reveal markedly high shielding behavior towards successive gamma irradiation, due to the presence of both high content of heavy Pb2+ ions and the sharing of phosphate as a partner. With TM-doped samples, the observed induced bands are virtually varying and related to the type of the sharing TM ions. Infrared absorption spectra reveal in the undoped and TM-doped glasses characteristic structural phosphate groups mainly consisting of metaphosphate and pyrophosphate units. Transition metals are assumed to cause depolymerization of the phosphate glass network with different ratios but the changes in IR spectral data are limited due to the low doping level. Gamma irradiation of the samples is assumed to cause changes in the bond angles or bond lengths of the structural phosphate units within network as evident in the variation of the intensities of the IR bands. 相似文献
52.
Cyclocondensation reaction of 3-hydrazinyl-2-naphthoic acid with diphenyl-N-cyanoimidocarbonate furnished the target 2-phenoxy-benzo[g][1,2,4]triazolo[1,5-a]quinazolin-5(4H)-one (1) in high yield. Alkylation, thionation and chlorination of the lactam group in the compound 1 produced a variety of derivatives 2–17. Their structures were characterized by NMR and HREI-MS analyses. 相似文献
53.
One‐pot Synthesis of 1,2,3,4‐Tetrahydropyrimidin‐2(1H)‐thione Derivatives and their Biological Activity 下载免费PDF全文
Mounir A. I. Salem Magda I. Marzouk Marwa S. Salem Ghazala A. Alshibani 《Journal of heterocyclic chemistry》2016,53(2):545-557
2‐Thioxo/oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate derivatives 2a , 2b , 2c , 2d were prepared by the reaction of ethyl acetoacetate and thiourea or urea with aldehydes using NH4Cl as a catalyst. Compounds 2a and 2c reacted with mono and bihalogenated compounds such as ethyl iodide, chloroacetonitrile, epichlorohydrin, acetyl chloride, ethyl bromoacetate, chloroacetic acid, chloroacetylchloride, and/or oxalyl chloride to afford compounds 3 , 4a , 4b , 5 , 6a , 6b , 7 , 8 , 9 and 10 , respectively. Compounds 2a , 2c , and 7 were allowed to react with p‐fluorobenzaldehyde to yield the corresponding products 11a , 11b , and 12 , respectively. Oxidation of 2a and 2c gave 2b , 13a , 13b , 14 , 15 , 16 dependent on the oxidizing agent used. Vilsmeiere‐Haack formylation of 2a and 2b with POCl3/DMF afforded 17a and 17b . Chlorination of 2b and 2d gave the chlorinated derivative 18a and 18b , which reacted with thiourea to give thioureidopyrimidine 19a and 19b . Reactions of 2a with hydrazine monohydrate, semicarbazide hydrochloride, and sodium hydroxide gave compounds 20 , 21 , 22 , respectively. The cytotoxicity and in vitro anticancer evaluation of some prepared compounds have been assessed against two different human tumor cell lines including breast adenocarcinoma MCF‐7 and human hepatocellular carcinoma HepG2. Antimicrobial and antioxidant activities of some compounds were investigated. The newly synthesized compounds were characterized by IR, 1H‐NMR, 13C‐NMR, and mass spectral data. 相似文献
54.
Mona M. Marzouk Sameh R. Hussein Mona E.S. Kassem Salwa A. Kawashty Sabry I.M. El Negoumy 《Natural product research》2016,30(13):1537-1541
Twelve compounds were isolated from Chrozophora tinctoria (L.) Raf. They were identified as kaempferol, kaempferol 3-O-β-glucopyranoside, kaempferol 3-O-(6″-α-rhamnopyranosyl)-β-glucopyranoside, quercetin, quercetin 3-O-β-glucopyranoside, quercetin 3-O-(6″-α-rhamnopyranosyl)-β-glucopyranoside, apigenin, apigenin 7-O-β-glucopyranoside, acacetin, gallic acid, methyl gallate and β-sitosterol-3-O-β-glucopyranoside. Their structures were elucidated by chemical and spectral methods. Furthermore, chemosystematics of the isolated compounds is briefly discussed. It was indicated that C. tinctoria is the only species of Chrozophora that has the capability to synthesis kaempferol aglycone and their glycosides, and the finding is supported by its distinct morphological and anatomical aspects. 相似文献
55.
A novel polymeric membrane sensor sensitive to (4-sulphophenylazo-)1-naphthylamine (SPAN) based on the use of tris(bathophenanthroline) Ni(II)–SPAN ion pair as an ion exchanger in plasticised PVC membrane is described. The sensor exhibits a linear calibration plot with near-Nernstian anionic slope of −55.0±0.3 mV log[SPAN]−1 over the concentration range 10−6–10−2 mol l−1 at pH 7. The sensor shows working range over the pH 6–8, response time of 20 s for 10−5 mol l−1 and operational lifetime of 8 weeks. The sensor is used for quantification of micro quantities of nitrite ion by a prior conversion into the more lipophilic SPAN ion, which is measured with adequate sensitivity, and high selectivity using SPAN sensor. Validation of the method according to the quality assurance standards shows good performance characteristics. The sensor is satisfactory utilised for potentiometric determination of nitrite ion in wastewater samples and meat products. The results are favourably compared with data obtained using the standard spectrophotometric procedure involving the same reaction. 相似文献
56.
Diphenhydramine (DIPH) has become one of the world‘s most widely abused over-the-counter medications. In addition to relieving allergy symptoms, it is also recognized for causing elevated energy and mild euphoric effects. The U.S. Food and Drug Administration (FDA) has recently warned about serious problems at high doses including heart problems, seizures, coma or even death among addicted teenagers. Herein, a simple, cost-effective, and reliable nanocomposite based electrochemical sensor was designed for DIPH quantification in biological fluids. Introducing the functionalized Fe3O4 nanoparticles (NPs) into the inner-filling solution and the PVC-based ion sensing membrane has been employed and compared to the classical potentiometric approach. The nanoparticles were incorporated to endorse in situ cooperative ion-pairing interaction between the ionophore and DIPH, and to improve the selectivity and detection limit (9.5×10−8 M). Nernstian potentiometric response was achieved for DIPH over the concentration range of 1.0×10−7 to 1.0×10−2 M with a slope of 59.0±0.2 mV/decade. Inherent merits of the proposed sensor include fast response time (6 s), superior stability (60 days) with higher sensitivity and selectivity towards DIPH without interference from co-formulated drugs and several ions commonly found in biological matrices. The proposed sensor was successfully applied to the potentiometric determination of DIPH in different biological fluids (plasma and human milk) with an average recovery of 99.06±1.95 % and 100.34±1.92 %, respectively. As a consequence, the developed ISE might be the ideal choice for in-line DIPH measurements in plasma samples to identify overdose ingestion and its related symptoms, as well as for quality-control laboratories without prior treatments. 相似文献
57.
Numerical Algorithms - Motivated by the high accuracy requirements and the huge ratio of the largest to smallest time scales of Coulomb collision simulations of a considerable number of charges, we... 相似文献
58.
Mansour S. Y. Sayed G.H. Al-Halim S. A. Marzouk M. I. Shaban S. S. 《Russian Journal of Organic Chemistry》2020,56(3):465-475
Russian Journal of Organic Chemistry - New diaryl-substituted pyridine, pyrimidine, pyrazole, and isoxazole derivatives bearing biphenyl-4-yl and 4-(dimethylamino)phenyl substituents have been... 相似文献
59.
Antar A. Abdelhamid Hanan A. Salah Adel A. Marzouk 《Journal of heterocyclic chemistry》2020,57(2):676-685
The pyrrolidinium hydrogen sulfate (PHS) was used as an excellent ionic liquid catalyst for the preparation of many imidazoles moiety, which have biologically application via one-pot multicomponent reaction. Imidazoles were afforded through the reaction of equimolar from 1,2-diphenylethane-1,2-dione, ammonium acetate, different aromatic aldehydes, and ethyl glycinate hydrochloride. This method has the advantages of giving excellent yield, shortened reaction times, and ease of establishment. Moreover, the yielded of imidazoles components can be purified and crystallized by a nonchromatographic technique, and the catalyst can be reused. These entire novel synthesized components have been identified by spectral data: IR, NMR and mass spectra. These compounds have an in vivo antioxidant activity on experimental animals (rats). 相似文献
60.
Ayish Nada S. Mahmoud Amr M. Fayed Ahmed S. El-Zeany Badr A. Marzouk Hoda M. 《Journal of Solid State Electrochemistry》2022,26(3):843-853
Journal of Solid State Electrochemistry - Solid-state electrochemical sensors have shown tremendous promise for portable and reliable ion detection, thanks to implementing new functional materials... 相似文献