The complexation between folic acid and a typical polyaromatic hydrocarbon, fluorene, was investigated using FTIR and UV spectra. Appearance of a new IR band at 2401cm−1 demonstrates that NH2–C=N moiety on pterin ring in folic acid is protonated when fluorene is introduced. The emergence of two charge transfer bands at 217 nm and 278 nm in UV difference spectra shows the presence of π-π complexation between folic acid and fluorene. These experiments confirm that fluorene could combine with the pterin ring of folic acid through π-π donor–acceptor interaction and induce the protonation process in folic acid upon strengthening electron accepting ability of pterin ring. The results suggest that complexation between fluorene with folic acid necessarily change their charge distribution and the surroundings. It is inferred that not only biotransformation process of folic acid, but also the toxicity of polyaromatic hydrocarbons could be changed.
The erythrocyte aggregation is an important physiological phenomenon in the circulation of blood. It is a basic characteristic of normal blood that plays a major role in the cardiovascular system, especially in the microcirculation. This study explained the kinetics of single cells rouleaux formation one- dimensional aggregate and three- dimensional aggregate, during simultaneous, and the effect of hematocrit on the process of aggregation and sedimentation. The present study was done on forty one healthy subjects. Laser light is passed through a well mixed sample of blood and the forward scattered light intensities recorded continuously. The samples were prepared with different hematocrit, (10%, 15%, 20%, and 25%). Increasing
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The proposal of nonlinear models is one of the most important methods in time series analysis, which has a wide potential for predicting various phenomena, including physical, engineering and economic, by studying the characteristics of random disturbances in order to arrive at accurate predictions.
In this, the autoregressive model with exogenous variable was built using a threshold as the first method, using two proposed approaches that were used to determine the best cutting point of [the predictability forward (forecasting) and the predictability in the time series (prediction), through the threshold point indicator]. B-J seasonal models are used as a second method based on the principle of the two proposed approaches in dete
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ABSTRACT. 4-Sulfosalicylic acid (SSA) was used as a ligand to prepare new triphenyltin and dimethyl-tin complexes by condensation with the corresponding organotin chloride salts. The complexes were identified by different techniques, such as infrared spectra (tin and proton), magnetic resonance, and elemental analyses. The 119Sn-NMR was studied to determine the prepared complexes' geometrical shape. Two methods examined the antioxidant activity of (SSA) and prepared complexes; Free radical scavenging activity (DPPH) and CUPRRAC methods. Tri and di-tin complexes gave high percentage inhibition than ligands with both methods due to tin moiety; the triphenyltin carboxylate complex was the best compared with the others. Also, antibacter
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In recent years, there has been a rapid development in research on high performance ceramics for mechanical, electrical and medical industries. This development will be shown for alumina as a representative for oxide ceramics powders.
Dry–pressing forming technique was used to prepare different ceramic compacts for alumina grafted by polymethacrylate polymers. All Alumina compact were fired firstly at 1200 ◌ْ C, then
at 1600 ◌ْ C.
Mechanical strength was examined in different means, some
depends on compression and other depends on impact. Hardness was
also measured .The results obtained were compared with that of
Alumina compact prepared under the same condition from Alumina
especially made for pressing .
Amidst the changes resulting from the subject matter of expression in art. The necessity of searching for the expressive features of thought that leaves different imprints with aesthetic features and values which called for re-modifying the expressive vision of contemporary drawings. Therefore, this research has been concerned with the study of (abstract expressive features in the drawings of (Serwan Baran) and (Eric Barto) - a comparative study), and the research includes four chapters. The first chapter is devoted to explaining the research problem, its importance, need, purpose, and limits, then determining the most important terms mentioned in it. Where the research problem dealt with the subject of abstract expressive feature
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The organic compound imidazole has the chemical formula C3N2H4. Numerous significant biological compounds contain imidazole. The amino acid histidine is the most prevalent. The substituted imidazole derivatives have great potential for treating a variety of systemic fungi infections. Thiourea is an organosulfur compound with the formula SC(NH2)2. It is a reagent in organic synthesis. In this paper, some new imidazole and thiourea derivatives are synthesized, characterized, and studied for their biological activity. These new compounds were synthesized from the starting material terephthalic acid, which was transformed to corresponding ester [I] by the refluxing of diacid with methanol in the presence of H2SO4 as a catalyst, compound [I] con
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2-Amino-5-aryl- 1,3-thiazole-4-carboxylic acid (A1-A3) were synthesized from the reaction of various aromatic aldehyde with dichloro acetic acid and thiourea. The synthesis of 2-[[(Saminosulfinim-idoyl)(aryl)methyl](benzoyl)amino]-5-aryl-1,3-thiazole-4-carboxylic acid (A22-A30) was perfomed starting from (A1-A3) by two steps using Schiff's base (A4-A12) prepared from the reactant compounds (A1-A3) with different aromatic aldehyde. Finally two types of imide derivatives were obtained from reactant compounds (A1-A3) with malic anhydride (A31-A33) and phthalic anhydride (A34-A36) in the presence of glacial acetic acid. All proposed structures were supported by FT-IR and UV-Visible spectroscopic data.