Rafidain Journal of Science

The study included isolation and identification of Saccharomyces cerevisiae var. boulardii from fresh and dried fruits such as (fig, grape, apricot, lychees, mangosteen) which were available in local markets in Erbil city. Fifty isolates of the yeast were obtained depending on morphological, physiological and biochemical tests. The antibacterial activity of the isolated yeasts against pathogenic bacteria Salmonella enteric sub spp.enterica (Typhimurium) in vitro was determined by Well's Diffusion method. Most of the isolated yeasts showed antibacterial activity against tested bacterium, the highest diameter of inhibition zone was (16 mm) for isolates (S.b32). The ability to tolerate different concentrations of bile salt and gastric acids were also studied. Ten strains of the isolated yeast had the highest inhibitory activity and were used to study physiological properties (bile salt concentration and gastric acidity) which were (S.b6, S.c1, S.b2, S.c36, S.b13, S.b28, S.b32, S.b22, S.b48, and S.b5). The result showed that the isolate (S.b32) was more resistant than other strains when exposed to bile salt and gastric acids.

Samples from four types of dried fruits (apricot, fig , grapes and plum) were collected from local markets at Duhok governorate and surveyed for their contamination with Aspergillus species. A total of 20 species of Aspergillus were isolated on DRBC medium. A.awamori, A.carbonarius, A.flavus, A.fumigatus, A.japonicus, A.niger, A.ochraceus, A.parasiticus and A. tubingensis were detected from all types of dried fruits. The most frequent species was A.niger followed by A.flavus. Aflatoxigenic potentials of selected strains from Aspergillus section Flavi were detected by ELISA technique. Aflatoxin potential was detected in cultures from all isolates of A.flavus and A.parasiticus .Aflatoxin was found at levels from 10-344 ppb for A.flavus isolates and from 71-355 ppb for A.parasiticus.

The present study aimed to determine the antibacterial activity of lactic acid bacteria metabolites against Listeria monocytogenes which was isolated from some foods in local markets of Erbil and Koya cities; 225 food samples were examined for the presence of Listeria species particularly L. monocytogenes from October 2010 to March 2011. The studied samples included 70 samples of raw chicken meat, 55 samples of raw milk, 50 samples of cheese and 50 samples of raw red meat. According to motility test, hemolysin production, sugar fermentation test, 8 isolates of L. monocytogenes were identified, 1 (2 %) isolate from cheese, 2 (4 %) isolates from red meat and 5 (7.3 %) isolates from chicken meat. The percentages of contaminated foods for Listeria species from chicken meat, raw milk, cheese and red meat were 20, 9, 20 and 22% respectively. With respect to the biocontrolling attempt, the effect of cell free extract (CFE) of lactic acid bacteria (LBA) which is considered as safe against isolated L. monocytogene was used as biocontrolling agent. The CFE of lactic acid bacteria which isolated from local dairy products, was tested for its controlling ability by agar diffusion method, the CFE showed inhibition zone from (15-23 mm) in diameter. Also the minimum inhibitory concentration MIC of CFE was determined at three additive percentages (0.5, 1.0 and 1.5ml to 10 ml of nutrient broth), the inhibition percentage ranged from (28.75 - 48.97) at (0.5 %), (52.13-95.55) at (1 %) and (82.93 -98.15) at (1.5 %) additive percentage of CFE of LAB.

This research was concerned with the measurement of latent matrix metalloproteinase-1 (MMP-1) activity in serum and synovial fluid (SF) of rheumatoid arthritis patients, and evaluation the effect of some factors like gender, age, geographical place and smoking on the enzyme activity.
The study included (158) patients (132 female, 26 male) aged from (19-83) year, attending the rheumatology clinic at Ibn Sina teaching hospital in Nineveh Governorate.
Sixty healthy volunteers of matched age and gender were utilized as control.
The results showed that the activity of enzyme was significantly different between the SF and the serum of patients with RA (586.85 ± 40.89 ng/ml, vs. 249.45 ± 61.11 ng/ml; P< 0001) respectively, and between serum of RA patients and serum of control (249.45 ± 61.11 ng/ml, vs. 125.46± 54.88; P< 001) respectively.
The results indicated that the number of rheumatoid arthritis females were more than males by (5) times and it is most common after the age between 40th and 50th years. Moreover, the results showed that the number of patients who live in urban places is higher than that in rural places.
The study, also, showed that the enzyme activity was significantly increased among smoker patients.
Finally the results showed that there was no significant effect of age, gender and geographic place on the enzyme activity.

A simple, rapid and sensitive spectrophotometric method is proposed for the determination of niclosamide (NIC) in pure form and in its pharmaceutical preparations. The method is based on the reduction of niclosamide by zinc powder in acidic medium followed by the diazotization of reduced niclosamide, then coupling with 2,6- dihydroxybenzoic acid to give a yellow colored product which is water – soluble and has a maximum absorption at 456 nm with a molar absorptivity of 2.36×104 l.mol-1. cm-1. The color reaction is highly stable and does not show a significant change in absorbance up to 24 hours. Beerُُs law is obeyed in the concentration range of 5–300 µg of niclosamide in a final volume of 10 ml. The method has been successfully applied to the determination of niclosamide in tablets.

A new coordination complexes and adducts of the general formulas [M(hpipdtc)2] and [M(hpipdtc)2Ln] where M= Mn(II), Fe(II), Co (II), (hpipdtc)=4-hydroxypiperidinedithiocarbamate, n=1 L= 1, 10phen, en, n=2 L=4-picoline, 3,5-luitidine, triphenylphosphine have been prepared and characterized by metal analyses, infrared, molar conductance measurements, electronic absorption spectra, and susceptibility measurements. Magnetic moments and electronic spectra, suggested tetrahedral geometry for complexes of the type [M(hpipdtc)2] and an octahedral geometry for their base adducts.

A series of new Schiff bases, namely 4-(substituted benzylidene amino)-4H-1,2,4-triazoles (5a-j) derivatives were synthesized by the reaction of symmetrical substituted 4-amino-1,2,4-triazole (4) and appropriate substituted aromatic aldehydes in presence of acetic acid. The synthesized imines were characterized on the bases of their physical properties and spectroscopic data. Some of these compounds were tested for biological activities as antibacterial and antifungal agents and showed a significance to moderate activity.

A sensitive and selective spectrophotometric method for the determination of lead (II) in aqueous solution using zincon reagent has been developed. The pinkish red coloured complex was formed at pH 9.5 which shows maximum absorption at 543 nm. Beer's law is obeyed in the range 0.04 –1.2 ppm with a molar absorbtivity of 9.84 x 104 l.mol -1cm-1. The established stoichiometry is l:l ligand: metal. The method seems to be selective through the study of cationic and anionic interferences, easy, rapid, accurate, reproducible, and the complex is stable for 24 hours. The optimum conditions and the applications of the method have been studied for the assay of lead in different water samples.

The study included an attempt to isolate and purify obestatin from healthy human plasma using different biochemical techniques. Two proteinous peaks had been isolated by gel filtration chromatography (Sephadex G-50) from the precipitate produced by precipitation using cold acetone. It was found that the second peak (peak B) only had an obestatin. Two proteinous components had also been isolated by the same technique using Sephadex G-25 from the peak B. It was found that the second peak (peak D) had a high concentration of obestatin .
Furthermore, the purity of the isolated obestatin (peak D) had been identified by the reversed phase high performance liquid chromatography and by SDS-polyacrylamide gel electrophoresis technique. The results obtained from the RP-HPLC showed that there was a good identity in retention time between the standard and the isolated obestatin (peak D).
The approximate molecular weight of partially purified obestatin was (2573 ± 100 Da) and (2660 Da) using gel filtration chromatography by Sephadex G-25 and ( SDS-PAGE) technique respectively.
The effect of the isolated obestatin (peak D) on some biochemical parameters in normal and alloxan induced diabetic male rats had been studied. After one week of treatment, the results showed that the obestatin at the dose (1 µmol / kg of body weight / d) caused a significant decrease in the levels of glucose, total lipids, total cholesterol, triglycerides, LDL-C, VLDL-C and MDA, in a addition to a significant increase in the levels of HDL-C in normal and alloxan induced diabetic rats and GSH in alloxan induced diabetic rats.
It was concluded that the isolated obestatin from plasma had a an important role in metabolism of glucose and lipid profile in normal and alloxan induced diabetic rats.

In this papers the novel photonic crystal fibers (PCFs) which consist of air holes surrounded by other substances with triangular lattice arrangement have been assumed. A Full-vector plane wave expansion method (FV-PWEM) has been implemented to calculate the dispersion properties of PCF which possess circular air holes with hole radius , lattice constant , and air filling fraction . Then the effect of up-doping has been studied using two different germanium dioxide percentages. As a result, a tuning of the total dispersion curve has been obtained.

This work deals with the implication of the concept of the energy density ρ at three different eras (radiation, matter and dark energy dominated eras) through the evolution of the universe. The solution of the Einstein's equations (Friedmann – Robertson – Walker equations, FRW), yields two explicit forms of the scale factor R(t): one is the power-law solution for both radiation and matter dominated eras and other is the exponential solution for the dark energy dominated era.
In the present work an equation for the three parameters has been derived, Hubble (H), redshift (z) and deceleration (q), in three different eras, with a thorough discussion.

In this paper a new semi empirical equation describing the track diameters of α particles in CR-39 is presented. The equation involves three free fitting parameters. It is shown that this equation can reproduce tracks diameter formed on the CR-39 by alpha particles at 3.1MeV, different etching times and temperature (70, 75, 80, 85) oC . Parameters values obtained from the experimental data were used to predict etched track diameters at different temperatures (T=70-85)oC and etching times (t=0-6)h. The suggested empirical equation is self consistent as far as reproducing all features of track diameter development as a function of etching time and temperature.