Classical and Advanced Chemical Sciences
Two different types of colloidal gold nanoparticles, produced as hydrosol, are recognized from their electronic absorption spectra. Gold nanorods with aspect ratio in the range between 2 and 4 and average diameter between 10 and 15 nm are produced using AuCl3 and hydroxylamine. The surface plasmon resonance (SPR) band of gold nanorod undergoes a blue shift of about 50 nm on treatment with ozone. On the other hand, spherical gold nanoparticles with average diameter around 20 nm are produced from AuCl3 reduced with black tea infusion. When treated with ozone the SPR band of the spherical gold nanoparticles show a red shift of more than 50 nm. This demonstrates that the shape of the gold nanoparticles deeply affects their response in the interaction with chemicals in view of the potential analytical application of gold nanoparticles as active materials in chemical sensors. A theoretical rationalization of the results is proposed.
Keywords: gold nanoparticles; spherical particles; nanorods; ozone; ozone detection
The title compound, 2-amino-4-(3-bromophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (C18H17BrN2O2), was synthesized, in 86% yield, by one-pot multicomponent reaction of 3-bromobenzaldehyde, malononitrile and dimedone using 10 mol % urea as an organo-catalyst at room temperature. It crystallizes in the monoclinic space group C 2/c with the unit-cell parameters: a= 23.557(2), b= 9.2963(7), c= 15.7502(12) Å, β = 93.430(8)o and Z = 8. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.0585 for 1411 observed reflections. The packing between the molecules within the unit cell is stabilized by N-H..O and N-H…N type of intermolecular hydrogen interactions.
Keywords: Crystal structure, direct methods, hydrogen interactions
Acidic and basic properties of β -substituted derivatives of tetraphenylporphyrin are studied. First and second stage ionization constants for ligands investigated are reported. Acidic properties of porphyrins are in good agreement with classical theories about influence of substituent’s nature and geometrical structure of macrocycle on their physical and chemical parameters. It is found that porphyrins have catalytic activity in heterogeneous oxidation of N,N-diethylcarbamodithioate.
Keywords: porphyrins, structure, acid-base properties, metallocomplexes, catalytic activity
Materials and Environmental Chemistry
This study is made to prove the efficiency of the activated carbon (AC) of Lebanese Cymbopogon citratus in the adsorption of lead (Pb(II)) from aqueous medium. The adsorption was found to be dependent on initial metal ion concentration, pH of the solution, temperature, contact time and adsorbent dose. The maximum adsorption capacity was found for the concentration of 450 mg L-1, pH 4, temperature 25 oC, contact time 2 h, and adsorbent dose 1g. The equilibrium adsorption was better described by Freundlich isotherm model rather than Langmuir model. The kinetic data were better represented by the pseudo-second-order than the pseudo-first-order kinetic model. Thermodynamic studies showed that the process was exothermic and spontaneous. The results of this study reveal that the activated carbon (AC) of Lebanese Cymbopogon citratus is a very effective and environmentally friendly adsorbent, with low cost for Pb(II) removal.
Keywords: Activated carbon, adsorption, isotherm, kinetic, thermodynamic.
Chemical and Biological Aspects of Life
The aim of this study was designed to determine whether maternal supplementation with olive oil influence plasma lipid profile and oxidant/antioxidant status later in life of rats with cafeteria- diet-fed during gestation and in their offspring throughout adulthood. Altering the fatty acid profile of rat diets during the gestation has long-term consequences for the growth and development of their offspring. Our results clearly demonstrate that maternal intake of olive oil before gestation, during gestation and during lactation display remarkable health benefits for the prevention of obesity and associated metabolic disorders by decreasing the lipoprotein metabolism and oxidant/antioxidant status alterations brought about by obesity in offspring at birth until adulthood.
Keywords: Maternal nutrition, metabolic and redox status, olive oil, obesity, offspring
With the fast developing nanotechnology, questions are being raised about the potential toxic effects of the nanomaterials on human health. The effects of lanthanum oxide nanoparticles on the primary osteoblasts are investigated in the present study. As an indicator of membrane damage, lactate dehydrogenase is quantitatively assessed. The quantitative analysis on cellular uptake of lanthanum oxide nanoparticles could be detected by flow cytometer and inductively coupled plasma mass spectrometry respectively. The results demonstrate that lanthanum oxide nanoparticles can enter cells through cell membrane and the nanoparticles taken up by the cells followed dose and time dependent effect. The method could be used for the initial screening of the uptake potential of nanoparticles as an index of nanotoxicity.
Keywords: Rare earth metal oxides; Lanthanum oxide nanoparticles; Cellular uptake; Osteoblasts; Nanotoxicity
Osteoarthritis (OA) is the most common degenerative joint disorder that ultimately results in the progressive destruction of articular cartilage. The occurrence of knee osteoarthritis (OA) increases with obesity and is more common in women compared with men. Thirty patients (20 females, 10 males) clinically diagnosed with knee OA admitted to Baghdad teaching hospital between January 2015-June 2015. Patients between 35-70 year of age and 30 healthy subject (20 females, 10 males) ages matched. The results showed that increased body mass index (BMI) is a well-recognized risk factor for knee osteoarthritis, and the effect of obesity is a stronger predictor of developing knee OA symptoms in women than men. There was also a significant difference between lactate dehydrogenase (LDH) in serum patients and control (p< 0.01). This study supported a positive association between systemic BMI and OA. Furthermore, serum LDH activity could be of diagnostic value for identifying osteoarthritis.
Keywords: osteoarthritis, LDH, obesity, BMI
Industrial and Engineering Chemistry, Biotechnology
The heat-resistant nickel- and nickel-molybdenum electroplatings of high quality were prepared on copper and aluminum bases using the method of galvanic electrolysis. The platings are uniform, non–porous and are characterized by high adhesion. The optimal parameters of the process (current density, electrolysis duration, ratio between anode currents of molybdenum and nickel) are determined. MicroX-ray and fluorescence analyses of the obtained samples are carried out. Molybdenum content in the plating is determined. The existence of finedispersed phases of MoNi3 and MoNi4 are established. Electrical and mechanical properties of above – mentioned platings are studied after the heat treatment for their operation at high temperatures.
Keywords: electrolysis of fused salts, electroplating, nickel, molybdenum, electrical and mechanical properties