فهرست مطالب

Iranian Journal of science and Technology (A: Siences)
Volume:33 Issue: 4, Autumn 2009

  • A4
  • تاریخ انتشار: 1388/10/11
  • تعداد عناوین: 8
  • M. Hetta, S. Hassan, S. Abdel-Tawab, M. Bastawy, B. Mahmoud Page 287
    The polysaccharides of Acanthophora spicifera and Cystoseira trinode were isolated and their components identified using different chemical and spectral techniques. Their effects were evaluated for the first time on hyperlipidemic rats. Atorvastatin Ca (Lipitor®) was used as a reference drug. Results revealed that the polysaccharides isolated were of sulfate type. Acanthophora spicifera lowered the level of total serum lipids, total cholesterol (TC), triglycerides (TG) and low-density lipoproteins (LDL-C) by 48%, 49.6%, 63% and 80.6% respectively. High-density lipoproteins (HDL-C) level was elevated by 1.14 fold. For Cystoseira trinode total lipids, TC, TG and LDL-C were decreased by 25.5%, 49%, 51% and 91% respectively. The level of HDL-C was elevated by 1.5 fold in comparison with the hyperlipidemic rats. The histopathological results proved the ameliorated effect after using the isolated polysaccharides of both algae. Alanine aminotransferase(ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were decreased in hypercholesterolemic groups by values of 63%, 34% and 45%, respectively when treated with A. spicifera extract. The treatment with C. trinode extract and Atorvastatin exhibited a noticeable amelioration in activity with hypercholesterolemic groups as compared to their corresponding controls.
  • M. N. Gheibi, B. Kholdebarin, F. Ghanati, S. Teimouri, N. Niroomand, M. Samavati Page 299
    Nickel (Ni) is one of the essential micronutrients for higher plants and its known function is being the metal component of urease. The effects of various Ni levels on urease activity in maize (Zea maize L.) plants grown in two nutrient media containing urea or ammonium nitrate as two separate nitrogen sources were investigated. The experiments were performed as completely randomized blocks with three replications.Treatments included two growth media, the nitrogen of which was either urea or ammonium nitrate added at the rate of 84 mg L-1 and four Ni levels (0, 0.01, 0.05 and 0.1 mg L-1) supplied as NiSO4. Plants were grown in the nutrient solutions for six weeks. On the second, fourth and sixth week of the growth period, both the leaves and root samples were taken to determine their urease activities. At the end of the sixth week, the dry weights of both the shoots and roots were also measured. Urease activity in leaves of corn supplied with urea increased significantly with the increase in Ni supply till the end of the 6th week sampling date, however in those supplied with ammonium nitrate, urease activity increased up to the 3rd Ni level and 4th week of sampling date, but was reduced at the 4th Ni level in the 6th week. Urease activity in the roots of corn plants supplied with urea was the highest at the 2nd Ni level at the end of the 2nd week. Increase in Ni levels and date of sampling resulted in a decrease in urease activity. However, in ammonium nitrate-fed plants urease activity in the 2nd week of the sampling date increased up to the 4th Ni level and for other sampling dates the activityincreased up to 2nd Ni level. Further increase in Ni supply and date of sampling resulted in a decrease in urease activity. Enzyme activity was higher in the roots than in the shoots and was also higher in plants supplied with urea, compared to those fed on ammonium nitrate. In maize plants supplied with urea, the dry weights of the shoots and those of the roots were also higher.
  • N. Kharazian, M. R. Rahiminejad Page 309
    This recent study documents the phenolic constituents of the Triticum L. species in Iran using thin layer chromatography. Species studied are related to 55 wild and cultivated accessions of four diploid and four tetraploid species, namely Triticum boeoticum subsp. boeoticum Boiss., T. boeoticum subsp. thaoudar Reut. ex Boiss., T. monococcum L., T. urartu Tum. ex Gand., T. turgidum L., T. dicoccoides (Korn. ex Ascher. et Graebn.) Thell., T. dicoccum (Schrank.) Schubl. and T. durum Desf. collected from natural habitatsand analyzed for their flavonoid compounds. The current study found that of a total of 20 flavonoid compounds, most of the derivatives were flavones, chalcones, and the others were mainly pseudobaptisin, sciadopitysin, baptigenin and fustin-3-O-glucoside. The basis of variation in these compounds was shown to be usable as an appropriate marker for chemotaxonomic studies.
  • E. Tazikeh, A. A. Saboury, G. Rezaei-Behbehani Page 317
    A thermodynamic study on the interaction between zinc ion (Zn2+) and human growth hormone (hGH) was studied at two temperatures of 27C and 37C in aqueous solution using an isothermal titration calorimetry. It was found that there is a set of three identical and non-interacting binding sites for Zn2+ ions.The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 1.54 mM and 17.6 kJ mol-1 at 27C and 1.93 mM and 7.1 kJ mol-1 at 37C, respectively. To reproduce the binding parameters of metal ionhormone interaction over the whole range of Zn2+ concentrations a solvation theory was applied.The binding parameters deduced from the solvation model were attributed to the structural change of hGH and its biological activity due to the metal ion interaction.
  • K. Javidnia, R. Miri, M. Assadollahi, M. Gholami, M. Ghaderi Page 329
    The antimicrobial activity of methanolic extracts from different parts of 11 indigenous wild plant species used in traditional medicines of Iran were tested against nine species of microorganisms: Escherichia coli, Staphylococcus aureus, Staphylococcus epidermis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, Bacillus subtilis, Aspergillus niger and Candida albicans. The antimicrobial efficacy was determined using the disk diffusion (0.5, 1, 2 and 4 mg/disk) and minimal inhibition concentration (MIC)method. Among the 11 tested herbs, 9 plants showed antimicrobial activity against one or more species of microorganism. The most active antimicrobial plants were Stachys obtusicrena, Anvillea garcinii, Salvia species, Otostegia persica and Teucrium persicum.
  • R. Shabani, S. A. Mozaffari, S. W. Husain, M. Saber Tehrani Page 336
    Fabrication of a cysteamine (CA) self-assembled monolayer (SAM) modified gold electrode insitu functionalized with L-Lysine (Lys) is presented and described. The fabricated electrode was used for highly selective and sensitive accumulation and the determination of copper ions (Cu2+) in a nanomolar concentration. Techniques like cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with an external redox probe (p-Benzoquinone) were used to investigate the layer-by-layer self assembly modification on a gold electrode, monolayer structure and the ion permeation through it. The differentialpulse voltammetric (DPV) method was used for determination of Cu2+. The results indicated that DPV peaks currents have a linear relationship with pCu in the concentration range of 1.0×10-12 - 1×10-6 M, with a correlation coefficient of 0.9982. The detection limit could be estimated 1.2×10-13 M according to the IUPAC recommendation (3σ).
  • H. R. Esmaeili, M. Ebrahimi, A. Teimori Page 349
    The karyotype of Zagros tooth-carp, Aphanius vladykovi (Coad) has been investigated byexamining metaphase chromosomes spreads obtained from gill epithelial and kidney cells. The diploid chromosome number of this species was 2n=48. The karyotype consisted of 8 submetacentric and 40 subtelocentric chromosomes (8Sm+40 St). The arm number (NF) was 28. Sex chromosomes were cytologically indistinguishable in this tooth-carp.
  • S. Sadeghi, J. Mohammadalizadeh Page 355
    Forty eight species of Odonata families, including Libellulidae (23 species), Aeschnidae (7species), Gomphidae (5 species), Cordulegastridae (1 species) from suborder Anisoptera and Euphaeidae (1 species), Calopterygidae (1 species), Lestidae (3 species), Platycnemididae (1 species) and Coenagrionidae (6 species) from suborder Zygoptera were collected from 46 sampling sites in Iran between early May 2001 tomid June 2002. Two species of Libellulidae (Libellula fulva and Sympetrum sinaiticum), and one species of Gomphidae, (Paragomphus sinaiticus) are recorded from Iran for the first time.