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  • Author or Editor: A. Soliman x
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Abstract  

New cadmium complexes of the salicylidene-2-amino-thiophenol (I) and 3-methoxysalicylidene-2-amino-thiophenol (II) Schiff bases have been prepared and characterized by elemental analyses, IR, 1H-NMR spectra, conductimetric and thermogravimetric analyses. The results suggested that the Schiff bases are bivalent anions with tridentate ONS donors derived from the phenolic oxygen azomethine nitrogen and thiophenolic sulphur. The formulae are found to be [MLH2O] and [ML2]for the 1:1 and 1:2 non-electrolytic complexes, respectively. The thermal decomposition of the complexes follows first order kinetics and the thermodynamic parameters of the decomposition are reported.

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Abstract  

A brief derivation of the Kissinger’s equation for analysis of experimental data of non-isothermal glass transition peaks based on the free volume model is given. This equation was applied successfully to Cu0.3(SSe20)0.7 chalcogenide glass for different heating rates. For granted this model, the obtained glass transition activation energy, E g must be constant throughout the whole glass transition temperature range. This required that T g to be determined for three characteristic temperature points for each DSC curve.

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Abstract  

The complexes of chromium and molybdenum with salicylidene-2-aminophenol (shaH2), salicylidene-2-aminoanisole (salanH2), salicylidene-2-aminoaniline (salphenH2) and biquinoline (biq) were studied using the thermogravimetric techniques. The thermal decomposition of all complexes was found to be first order reaction and the thermodynamic parameters corresponding to the different decomposition steps were reported. Molybdenum complexes were found to be more thermally stable and the order of stability was [Mo(CO)4(biq)]>[MoO(salphen)]>[MoO2(salphenH)2]>[MoO4(salan)2]>[MoO(sha)]. Similar trend was found for chromium complexes where [Cr(CO)4(biq)]>[Cr(CO)2(salphen)] >[CrO2(CO)2(shaH2)]>[CrO2(CO)2(salan)2].

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Abstract  

Solid complexes of five derivatives of thio-Schiff bases with La(III) and Ce(III) ions were prepared and characterized by elemental and thermogravimetric analyses. The suggested general formula of the solid complexes is [ML2(H2O)X]·2H2O, whereM=trivalent lanthanide ion,L=Schiff base andX=Cl or ClO 4 . Information about the water of hydration, the coordinated water molecules, the coordination chemistry and the thermal stability of these complexes was obtained and is discussed. Additionally, a general scheme of thermal decomposition of the lanthanide-Schiff base complexes is proposed.

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Abstract  

Labeling was carried out by direct iodination of thioguanine (100 μg) with radioiodine in a fast single step at 60 °C, to produce iodo-6-thioguanine (125I-S6G). Chloramine-T (200 μg) was used as oxidizing agent to oxidize the iodide ion to the iodonium ion, at pH 7 and the reaction time was 30 min. A high radiochemical yield of 96.4% was obtained. The labeled compound was quantitatively separated and purified by means of high pressure liquid chromatography (HPLC) with a radiochemical purity greater than 98%, which facilitates its clinical use for human application. The biodistribution of 125I-6-thioguanine was studied by injection of the tracer in both normal and tumor bearing mice. The uptake in ascetic fluid was 35.4 and 23.9% at 1 and 24 h post intravenous injection (h.p.i.), respectively, indicating the suitability of this labeled compound for use as a radiopharmaceutical agent.

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Two novel, sensitive, and selective stability-indicating chromatographic methods were described for the analysis of zopiclone (ZOP) in the presence of its degradation products, namely, 7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-yl-4-methylpiperazine-1-carboxylate (hydrolytic DEG) and 5H-pyrrolo[3,4-b]pyrazine-5,7(6H)-dione (oxidative DEG), in drug substance and product. The first method was an isocratic reversed-phase high-performance liquid chromatography (RP-HPLC) using Inertsil ODS3 (250 × 4 mm, 5 μm) column. Upon using HPLC, the run time could be reduced, and actually, the solvents consumption decreased. Quantification was achieved by detection wavelength at 237 nm, based on peak area. Chromatographic separation was performed over the range of 1–10 μg mL−1 with limits of detection (LOD) and quantification (LOQ) of 0.18 and 0.55 μg mL−1 and a mean recovery of 99.98 ± 0.55. The analysis was achieved at 30°C using a mixture of acetonitrile and water (50:50 v/v) as the mobile phase. The second method was thin-layer chromatography (TLC) applied for the separation and analysis of zopiclone in the presence of its alkaline, acidic, and oxidative degradation products. Chromatography was performed on silica gel 60 F254 plates with ethyl acetate‒methanol‒ammonia 33% (17:2:1 v/v) as the mobile phase. Successful resolution was observed with significant difference in the R F values, followed by densitometric measurement at 303 nm. Evaluation was carried out over the range of 0.1–2 μg per spot with a mean recovery of 100.52% ± 0.24. The developed methods were successfully applied to the analysis of ZOP in bulk powder, laboratory-prepared mixtures containing different percentages of its degradation products, and pharmaceutical dosage form. The degradation products were separated by HPLC as well as identified by TLC, infrared (IR), and mass spectrometry (MS) to confirm its structures and elucidate degradation pathway. The developed methods were validated as per the International Conference on Harmonization (ICH) guidelines. The results obtained by the proposed methods were statistically compared with the reported methods revealing high accuracy and good precision.

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Body size, physique, body composition and physiological performance of elite athletes's independent aspects, have aroused the interest of exercise scientists, but studies that combine these aspects in elite athletes are scarcely available. The aim of the present study was to describe the selected anthropometric and exercise physiological characteristics of some Hungarian top athletes. The investigated subjects were qualified Hungarian water polo players (n=25), paddlers (n=24) and modern pentathlonists (n=20), all of whom had been medalists at several continental and intercontinental competitions. The athletes' body composition was estimated by the Drinkwater–Ross (45) body mass fractionation technique. Peak physiological performance was estimated by graded exhausting spiroergometric treadmill exercise. Intergroup differences in mean height, body mass and body composition characteristics were significant at the 5% level of random error. By the results of spiroergometry, all the three groups compared could be qualified as physically excellently trained. The greatest oxygen uptake relative to body mass was found in the modern pentathlonists (73.22 ml´kg–1´min–1) and the lowest one (59.79) in the water polo players. The authors do not disregard the favourable effects of regular and adequate trainings in the development of the studied characteristics, but in their opinion the process of proper selection has been the most important factor that explains the observed significant intergroup differences.__

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Abstract  

A simulated borehole sonde has been assembled, with an aluminium casing of 70 cm in length and 12 cm in inner diameter. It contains a 5 Ci Pu–Be source with a neutron yield of about 5.45·106+10% n·cm–2·s–1, a shadow shield, and a Hp Ge detector of 15% efficiency and 2 keV FWHM for the 1.33 MeV line of60Co. Evaluations of the assembly through the dependence of thermal neutron flux on water content, matrix composition and borehole configuration have been performed. Accordingly, thermal neutron flux distributions have been measured around the sonde and inside the ore in both the simulated dry and water filled borehole. From these measurements one could estimate that the effective moderating thickness of water is about 4 cm, while the volume matrix of the ore to be investigated by this assembly is a slab of about 8 cm width and a height of about 15 cm. It also follows that the uranium-thorium ore analysis method described in this work may become important as a field neutron activation technique.

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Crude extracts of wild plant species were investigated for their activity against cotton aphid, Aphis gossypii Glov. Extracts were obtained by extracting fresh plants successively with solvents of variable polarities, hexane, diethyl ether, ethyl acetate, acetone and ethanol.  Among of 125 solvent extracts, hexane, diethyl ether, and ethyl acetate extracts of Hyoscyamus muticus, acetone extract of Verbascum sinuatum and ethanol extract of Rumex dentatus gave high toxicity against A. gossypii. Their LC50 values were 0.727, 0.883, 1.013, 0.805 and 1.143 mg/cm2, respectively.  Results indicated that 19 plant hexane extracts induced high toxic effect (LC50 ranged between 0.727 and 7.481 mg/cm2) against A. gossypii. Also, 22 plant diethyl ether extracts showed high toxic effect towards the tested insect (LC50's ranged from 0.883 to 10.00 mg/cm2). On basis of the LC50 value, 21 plant ethyl acetate extracts exhibited potent activity to A. gossypii (LC50 values ranged between 1.013 and 10.857 mg/cm2). Twenty-two acetone extracts that revealed high toxic effect (LC50 values ranged from 0.805 to 9.377 mg/cm2) to the tested pest, also 24 tested plant ethanol extracts that exhibited potent activity to A. gossypii (LC50 values ranged between 1.143 and 8.727 mg/cm2).  The ethanol plant extracts proved superior efficiency against A. gossypii followed by acetone, hexane, ethyl acetate and finally diethyl ether plant extracts.

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Abstract

Sustainable chemistry established one of kind standards to maintain protection of environment through using safer mobile phase composition and/or lower solvent consumption. A fast green micellar HPLC method was developed and applied for the first time aiming at simultaneous determination of chlorpheniramine maleate, one of the most widely used antihistamine in combination with levochlopersatine fenodizoate or dextromethorphan hydrobromide or dexamethasone, in their pure forms, laboratory prepared mixtures and pharmaceutical dosage forms used in alleviating the symptoms of cough resulting from common colds and allergy. The separation was achieved on Kinetex C18 column (100 mm × 4.6 mm i.d., 2.6-μm particle size) using micellar aqueous mobile phase consisting of (30 mM sodium dodecyl sulfate and 50 mM sodium dihydrogen phosphate, pH 5) and ethanol (85:15) with UV detection at 230 nm. The four drugs were successfully separated using isocratic elution in a single run not exceeding 7 min. According to ICH guidelines, the method was confirmed to be linear, accurate and precise over the concentration ranges of 5–60 μg mL−1 for chlorpheniramine maleate, 10–100 μg mL−1 for levocloperastine fenodizoate and dextromethorphan hydrobromide and 5–30 μg mL−1 for dexamethasone. In addition, the greenness of the developed method was assessed using two different tools indicating their least hazardous effect on the environment.

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