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51.
Sema Demirci Çekiç 《Analytica chimica acta》2004,505(1):15-24
XAD copolymer resins may be functionalized with heavy metal ion-selective ligands either by covalent linkage to the polymer backbone or by impregnation. These resins may be tailored to be specific for certain heavy metals by adjusting the adsorption and elution parameters, thereby enabling simple and cost-effective spectrophotometric and flame atomic absorption spectrometry (FAAS) determinations of these metals without requiring the more sophisticated coupled instrumental techniques. For the synthesis of o-aminobenzoic acid (ABA)-immobilized XAD-4 copolymer resin that is expected to preconcentrate a number of transition and heavy metals, the azo-linkage method was chosen. For this purpose the copolymer was nitrated, reduced to the corresponding amine, converted to the diazonium salt with nitrite, and reacted with o-aminobenzoic acid to produce the XAD-ABA sorbent. This sorbent was capable of preconcentrating Pb(II), Cd(II), Ni(II), Co(II) and Zn(II) from weakly acidic or neutral aqueous solution. The retained metals were eluted with 1.0 M HNO3 from the resin column, and were subsequently determinated with by flame atomic absorption spectrometry. The developed resin preconcentration and determination method was successfully applied to the analysis of a synthetic metal mixture solution, a certified reference material (CRM) of coal sample, and brackish lake water. 相似文献
52.
Erem Bilensoy Perran Moroy Yasemin ??rpanl? Tamer Bilensoy Sema ?al?? Leyla Mollamahmutoglu 《Journal of inclusion phenomena and macrocyclic chemistry》2011,69(3-4):309-313
Objective of this double-blind placebo-controlled study was to determine the efficacy of thermosensitive mucoadhesive gel loaded with 5-fluorouracil (5-FU):hydroxypropyl-ß-cyclodextrin (HP-ß-CD) complex via topical administration or intralesional injection for the treatment of human papilloma virus induced condyloma in 44 women. The diagnosis of human papilloma virus was established with clinical, histopathological and polymerase chain reaction techniques. Subjects were randomized into four parallel groups to evaluate topical or intralesional administration of drug-loaded or blank gel. The formulation used in the study consisted of 20% Pluronic PF 127 and 0.2% hydroxypropylmethylcellulose (HPMC) to render thermosensitive and mucoadhesive properties to the blank and drug-loaded gels. 5-FU was complexed to hydroxypropyl-ß-cyclodextrin to improve its solubility and this complex was loaded into thermosensitive gel to obtain controlled release of the cytotoxic drug in administration site over a two-week period cure regimen aiming therapeutic efficacy with lower 5-FU doses. Complete response was achieved in 61% of patients through intralesional administration while topical administration resulted in only 29% complete cure. Relapse rates of all therapy groups were significantly low in the 6-month follow-up time. 相似文献
53.
Mehmet Dindaroğlu Sema Akyol Hamza Şimşir Jörg-Martin Neudörfl Anthony Burke Hans-Günther Schmalz 《Tetrahedron: Asymmetry》2013,24(11):657-662
By using (R,R,R,R)-2,3-dimethoxy-2,3-dimethyl-1,4-dioxane-5,6-bis-diphenylmethanol (TARTROL) as a chiral building block, a set of six modular phosphine–phosphite ligands (with a 1,2-phenylene backbone) were synthesized and evaluated in the Cu-catalyzed asymmetric 1,4-addition of Grignard reagents to cyclohexenone. Ligands with bulky substituents at the ortho- and para-positions to the chiral phosphite moiety were found to be the most selective affording the 1,4-addition products with enantioselectivities of up to 84% ee. 相似文献
54.
Two New 2-Benzoylbenzoate Metal Complexes with Bapen: Synthesis,Spectroscopic and Crystal Structures
Abstract
Coordination compounds of compositions [Ni(bba)2(bapen)] (1) and [Cu(bba)2(bapen)]0.5H2O (2), where bba = 2-benzoylbenzoate, bapen = N,N′-bis(3-aminopropyl)ethylenediamine, have been prepared. The crystal and molecular structure of (1) and (2) were determined by X-ray analysis. Nickel and copper atoms are six-coordinated by four N atoms of amine and O donor atoms of 2-benzoylbenzoate anions, whereas 0.5 water molecule is situated outside the coordination sphere in (2). The calculated ∆(OCO) values are consistent with presence of monodentate carboxylate. Thermal analysis show that the mass losses of 1 in the temperature ranges 240–343 °C correspond to the decomposition of bba ligands, while the mass losses of 2 in the temperature ranges 105–125 °C correspond to the decomposition of crystal lattice water molecule. 相似文献55.
Kılıç Önder Belivermiş Murat Sıkdokur Ercan Sezer Narin Akyıl Erentürk Sema Haciyakupoglu Sevilay Madadzada Afag Frontasyeva Marina 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(2):699-706
Journal of Radioanalytical and Nuclear Chemistry - This study presents the first data of 210Po and 210Pb activity concentrations using moss species Hypnum cupressiforme from Thrace region, the... 相似文献
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58.
Mehmet Akkurt Sema
ztürk Hakan Üngren Mustafa Samac Hoong‐Kun Fun Yunus Akamur 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o598-o600
The title compound, C24H25NO7, is a racemic mixture of 2,3‐dihydro‐1H‐pyrrol‐3‐ones. It crystallizes in the triclinic system, space group P1, with Z = 2. The asymmetric unit contains two enantiomorphic molecules and the structure is stabilized by hydrogen‐bond contacts. 相似文献
59.
Bosco Peron Leutcha Jean Paul Dzoyem Jean-Bosco Jouda Denis Kehdinga Sema Virginie Flaure Tsague Tankeu Gabin Thierry Mbahbou Bitchagno Billy Toussie Tchegnitegni Flaure Rosette Ehawa Essoung Bruno Ndjakou Lenta Simon Fogue Kouam Florence Delie Alain Meli Lannang Norbert Sewald 《Molecules (Basel, Switzerland)》2022,27(15)
Twenty-two compounds were isolated from the fruit of Albizia lebbeck including one unprecedented, rare amino acid-derived zwitterionic and one new flavone derivative. The isolation was performed on repeated column chromatography over silica gel and their structures were determined by 1D-, 2D-NMR and HR-ESI-MS spectra together with reported data in the literature. The chemophenetic significance is also discussed. Some isolated compounds were reported for the first time to be found in the species. Additionally, compound 2 showed antibacterial activity and compounds 1 and 2 revealed moderate cytotoxic activity against the Raw 264.7 cancer cell line with IC50 values of 37.19 µM and 29.36 µM, respectively. Furthermore, a proposed biosynthetic pathway of compound 1 is described. 相似文献
60.
Mehmet Akkurt Sema
ztürk Hoong‐Kun Fun Zülbíye
nal Behzat Altural 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):e276-e277
The molecule of the title compound, C22H19N3O2S, is not planar. The dihedral angle between the two phenyl rings is 27.46 (7)° and in the dihydropyrazolopyrimidine ring the total puckering amplitude QT is 0.526 (3) Å. The structure is stabilized by both intra‐ and intermolecular C—H?O interaction, and by an intermolecular N—H?S hydrogen bond. 相似文献