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مجله علوم دانشگاه تهران | سال:1388 | دوره:35 | شماره:1 (بخش زیست شناسی)

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مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    1
  • End Page: 

    7
Measures: 
  • Citations: 

    0
  • Views: 

    222
  • Downloads: 

    84
Abstract: 

In this study the interaction between adriamycin and H1 histone protein of calf's thymus in different concentrations of the salt was investigated using the spectrum methods. The results demonstrate that in low concentrations, adriamycin increases the absorbance of histone H1 at 210 nm whereas in high concentrations it decreases the absorbance of histone H1. Repeating the experiments and using different concentrations of NaCl and MgCl2, one can conclude that the mentioned effects and the interaction between adriamycin and histone H1 increase Furthermore, in the presence of MgCl2 more changes were observed than NaCl. Therefore, based on the results, it may be concluded that not only the amount of the salt but its kind existing in the environment can also affect the process of interaction between adriamycin and histone H1.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    1
  • End Page: 

    5
Measures: 
  • Citations: 

    0
  • Views: 

    208
  • Downloads: 

    122
Abstract: 

The genus Allium encompasses over 750 species which have been classified into 15 subgenera and 72 sections. Section Allium is one of the most economically important sections of the genus, containing several medicinal and edible species. The section includes those species of Allium with a well developed bulb, stem (never basal) leaves and filaments in two distinct whorls, the outer nearly always simple and the inner tricuspidate. The objectives of the current study were to compare the scape anatomical features of some species of the section Allium. Some characteristics such as diameter of the cross section, palisade parenchyma, spongy parenchyma, and vascular bundles as well as number of vascular bundles, and sclerenchymatous layers were studied. On the basis of the results obtained, although the species of Allium section Allium form a relatively homogeneous group, some distinctions among cross-sections of scapes are evident. In fact, our findings offer a comprehensive survey using anatomical traits for delimitation and diagnosing species of the section Allium and provide a platform for further taxonomic investigations.

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Writer: 

HEJRI S. | SABOURA A.

Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    13
  • End Page: 

    19
Measures: 
  • Citations: 

    0
  • Views: 

    179
  • Downloads: 

    77
Abstract: 

Many industries generate phenolic pollutants during their manufacturing processes. Most of these compounds are toxic and have been classified as hazardous pollutants. Soybean peroxidase (SBP) catalyzes the oxidation and polymerization of phenolic compounds in the presence of hydrogen peroxide. The polymerized products can easily precipitate and be filtered from the solution. In this study phenolic solutions such as synthetic wastewater containing phenol, o-cresol and m-cresol, were treated with soybean peroxidase (SBP). The effect of some parameters was investigated on the removal process. The results showed that, an increase in hydrogen peroxide up to the optimum amount leads to an elevated removal of phenolic compounds. Higher concentrations of H2O2 inhibited the reaction. Treatment in the presence of PEG (polyethylene glycol) as an additive increased the effect of enzymatic removal. Application of different concentrations of the enzyme in the reaction mixture showed positive regression between enzyme concentration and removal of phenols. Studies to determine the optimum pH for enzyme activity revealed that elimination of phenols was improved in neutral pH. In addition, this study revealed that intact soybean seed-hulls were effective on the elimination of phenolic compounds in synthetic wastewater; treatment time significantly affected the concentration of seed-hulls needed for removal of phenols.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    17
  • End Page: 

    29
Measures: 
  • Citations: 

    0
  • Views: 

    192
  • Downloads: 

    94
Abstract: 

Kohgiluyeh and Boyer Ahmad is a small, roughly triangular area on the southwestern periphery of the Zagros Mountains. It is bordered to the west by Khuzistan Province, to the northeast by Chehar Mahal-e Bakhteyari and Esfahan Provinces and to the southeast by Fars and Boushehr Provinces. For more than a century scientists have gathered information on lizards from Iran, but there is limited information on the lizards of the high mountains of this province. In this study, 18 species of lizards belonging to 13 genera and five families identified at species and subspecies level. These lizards belonging to the families Agamidae (Laudakia nupta nupta, L.caucasia, L. microlepis, Trapelus lessonae and T. agilis agilis), Gekkonidae (Tropiocolotes helenae helenae, T. persicus persicus, Cyrtopodion scabrum, C.gasterophole, Hemidactylus persicus, c and Carinatogecko asperatilis), Lacertidae (Mesalina watsonana, Ophisops elegans elegans and lacerta princeps princeps), Scincidae (Mabuya aurata septemtaeniata and Eumeces schneiderii princeps) and Eublepharidae (Eublepharis angramainya).This is the first report of lizards from the area. This study mainly aims to describe the lizard species of this area and we hope the results will make a valuable contribution to the knowledge about herpetofauna of southwestern periphery of the Zagros Mountains.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    31
  • End Page: 

    35
Measures: 
  • Citations: 

    0
  • Views: 

    169
  • Downloads: 

    77
Abstract: 

At progressive stages of cancer the cancer cells migrate to adjust tissues and create new tumors in them. This stage of cancer is called as metastasis and many enzymes involved on it. Collagenase type IV is a proteolytic enzyme that because of its collagenase activity in over expression has a major role in development and metastasis of some cancers.A C/T polymorphism in the promoter region causes it’s over expression. The aim of the present study was to investigate the function of this polymorphism in tumor progression of breast cancer. This polymorphism was analysed by PCR-RFLP in 90 breast cancer patients and 100 health subjects. The stage and the size of tumors were detected by the related expert throughout the study. According to our findings there is a significant difference in the T allele frequency between the patients and control subjects (P=0.004; OR=3.27). Moreover, this allele presents in the 11 patients from the 14 patients that changed to metastasis position until the end of study. According to our results the function of this polymorphism may be related with the tumor progression and metastasis of breast cancer to the other tissues particularly the lymph nodes.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    37
  • End Page: 

    43
Measures: 
  • Citations: 

    0
  • Views: 

    156
  • Downloads: 

    104
Abstract: 

Today heavy metals are important environmental pollutants which generated from human activities and are one of the most important environmental stresses that cause molecular damages to plants through reactive oxygen species (ROS) formation such as H2O2. Heavy metals are absorbed and accumulated by plants thus are absorbed by human bodies through the food chain. Raphanus sativus is a herbaceous plant within the Brassicaceae family that has different varieties and is used as a food plant in different parts of Iran. Peroxidase (POD) is one of the most important enzymes in oxidoreductase superfamily that can metabolize H2O2. In this research we studied some growth parameters, peroxidase activity and their relationships with heavy metal content and other soil factors in three different populations of radish collected from Sari, Semnan and south of Tehran. After harvesting the plants shoots and roots POD activity was assayed spectrophotometrically at 470 nm. Our results showed total heavy metal content of shomal 3 station soil and radish plants was higher than other stations, so plants collected from this station had lowest root and shoot lengths, fresh weights, dry weights, protein content and leaf collrophyll content. The peroxidase activity in both leaves and roots of these plants was higher than plants of other stations therefore our results showed that with increasing heavy metal concentrations in soils peroxidase activity increased.

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Writer: 

SHOKOUHI KH. | GHANAATI F.

Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    45
  • End Page: 

    50
Measures: 
  • Citations: 

    0
  • Views: 

    199
  • Downloads: 

    80
Abstract: 

Aluminum (Al) is one of the major constituents of soil. In acid soils, solubilized Al3+ can be absorbed via roots there by affect plant growth .Inhibition of rapid root growth is reported in some plants. Also it is suggested that aluminum accumulates primarily and predominantly in the root apoplast where the pectin matrix with its negative charges is a major binding site.There are exceptional plants containing large amount of Al, so called Al hyper-accumulator, which often grow in acid soils. Tea plant is a well-known Al-accumulator plant, whose old leaves often contain more than 10000 ppm of Al. In the present research the effect of aluminum on the growth of suspension-cultured tea cells (Camellia sinensis L. cv. Yabukita) and the amount of their cell wall components were examined. The cells were treated with or without Al for 24 h. After that, cells were harvested and cell wall polysaccharides i.e., pectin, cellulose, hemicellulose A and B, and cellulose were isolated. The viability of cells, rate of aluminum absorption by them and their growth were measured .Compared with the control treatments, absorption of Al by cells and the weight of cell wall as well as content of HB and HA increased by Al treatment. The pectin content however reduced in Al-treated cells. The results suggest that the sites of absorption of Al are different among different wall components and function differently in releasing Al to the cytoplasm as well.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    51
  • End Page: 

    57
Measures: 
  • Citations: 

    0
  • Views: 

    239
  • Downloads: 

    121
Abstract: 

Anzali lagoon underwent considerable changes over the period of 1929-1996. All these changes as well as human intervention related to either decreases or increases in its open water area and depth. Therefore it is suggested that as a result of these changes, this aquatic ecosystem faces ongoing gradual alteration particularly on its ecological structures. In this study, major ecological pattern, with concerning different plant functional type and related other ecological factors were investigated. The results demonstrate that water depth plays leading role in shaping up the structure of different plant functional types and diversity. Therefore in course of defining conservation management in this protected area any factors affecting water depth should be taken in consideration.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    59
  • End Page: 

    66
Measures: 
  • Citations: 

    0
  • Views: 

    202
  • Downloads: 

    123
Keywords: 
Abstract: 

Dextrans is a group of polysaccharides (C6H10O5)n with glucose subunits. By consideration of its nonionic criterion, stability and other physico-chemical properties, dextran has a wide-range application in food, pharmaceutical and biochemical industries. In this study, effects of the most important factors affecting on the dextran production were studied by Leuconostoc mesentroides UTMC118. The results obtained showed that optimum conditions were: pH 9, 32oC, 50g/l sucrose, 20g/l yeast extracts 10% (v/v) inoculum size and there is no need to agitation.In order to find cheap and local media ingredients, dextran production by various concentration of molasses and baker-yeast were studied.Concentrations of 40g/l and 20g/l molasses and yeast extract found as the best industrial fermentation medium ingredients. Application of optimized condition increased the dextran concentration 3.5 times than that of control. Maximum dextran concentration was 80g/l. These results can reduce the cost of production by using the cheap raw materials.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    67
  • End Page: 

    74
Measures: 
  • Citations: 

    0
  • Views: 

    377
  • Downloads: 

    127
Abstract: 

Microbial enhanced oil recovery (MEOR) is use of microorganisms in petroleum industry. Bacillus species have been widely used as model organisms during MEOR research. In this study, isolation and identification of biosurfactant producing bacteria were assessed.60 strains of Bacillus isolated from contaminated area close to the storage Masjed Soleiman and distribution center of oil products In Tehran refinery. The confirm the ability of isolates in biosurfactant production, haemolysis test, emulsification test and measurement of surface tension were conducted. We also evaluated the effect of different pH, salinity concentration, temperatures and variety of carbon and nitrogen sources on biosurfactant production. Among important features of the isolated strains, two of the strains (P1, L2 Bacillus sp.) showed high salt tolerance (8%) and their successful production of biosurfactant and reduce surface tension was lowered from 69 to 30 and 29mN/m. The product of L2 and P1 is mainly lipopeptide. These emulsified crude oil and other hydrocarbon P1, L2 Bacillus sp. (E 24 = 90% -91%) respectively. These strains identified by morphological and biochemical technique using the taxonomic scheme of Bergey's manual of determinative bacteriology and 16SrRNA gene. The strains with approximate 97% and 99% belonged to Bacillus subtilis and Bacillus licheniformis. The optimum pH for these bacteria was 6.8 and the optimum temperature that they produce surfactant was 37oC .The best source of carbon was crude oil and best source of nitrogen was sodium nitrate. These strains in suitable for Exsitu MEOR.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    7
  • End Page: 

    12
Measures: 
  • Citations: 

    0
  • Views: 

    946
  • Downloads: 

    80
Abstract: 

Short and highly polymorphic DNA markers, so called short tandem repeats (STR), have become an important and efficient means in anthropology and forensic science. The Y chromosome STRs are male specific markers reside outside of pseudoautosomal region and path trough male lineage. Moreover the Y-specific markers may found to be associated with Y-linked phenotypes, including male infertility and gender-specific cancers. In current study we have examined YSTR polymorphism in a random sample of males among Iranian Sadat subpopulation. Sadat refers to descendants of Prophet Mohammad (through paternal lineage common to the first Imam of Shiite and his cousin Prophet Mohammad). The choice of this group had the advantage of being a decent lineage related through paternal lineage traced back to the common ancestor according to respective pedigrees. We have analyzed a random sample of the Sadat population using 6 Y-STR markers (DYS19, DYS385a, DYS389I, DYS390, DYS392, and DYS393).  Following the total DNA extraction from blood sample, PCR is performed and the products are visualized on agarose gel followed by denaturing polyacrylamid gel electrophoresis for further resolution. Comparing our date to that of some related data on other Iranians, Arab and Turkish male population revealed a significant lower genetic diversity in DYS385a, DYS390, and DYS392, and most notably at the latter locus.

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Issue Info: 
  • Year: 

    2009
  • Volume: 

    35
  • Issue: 

    1 (SECTION: BIOLOGY)
  • Start Page: 

    9
  • End Page: 

    16
Measures: 
  • Citations: 

    0
  • Views: 

    338
  • Downloads: 

    96
Abstract: 

RNA-directed RNA polymerases are main elements of the post transcriptional gene silencing (PTGS) pathway within eukaryotic cells. Previous studies indicated to the effective role of salicylic acid in PTGS phenomenon by inducing RDR1 gene expression. Using deifferent lines of transgenic tobacco plants in which the RDR1 gene was silenced moderately or highly in compare to the wildtype we evaluate the role of RDR1in tobacco (N. tabacum cv Samsun, NN) resistance to the systemic infection of Potato virus Y (PVYO).Antioxidative system of tobacco leaf apoplast including Polyphenoloxidase (PPO) and Peroxidase (POX) were quantitatively and qualitatively assessed for evaluating the resistance levels to Potato virus Y (PVYO) systemic infection in transgenic assay lines. Using semi-quantitative RTPCR method tobacco RDR1 and PVYO coat protein genes expression level were quantitatively determined through the RDR1 transgenic silenced tobacco lines and wildtype. Results of this study showed that, highly RDR1 silenced transgenic line accumulate the coat protein gene of PVY more than the wild type and moderately RDR1 silenced tobacco plant. In compare to the transgenic lines, considerable increase in polyphenoloxidase (PPO) specific activity observed for non transgenic tobacco wild type up to one month after PVY inoculation.However Peroxidase (POX) specific activity was higher in RDR1 silenced transgenic lines. Higher susceptibility to PVY infection through the RDR1 silenced transgenic lines was concurrent with the higher specific activity of Peroxidase enzyme. Our data elucidate the effective role of RDR1 gene in resistance of tobacco plants to systemic viral infection. Additionally enzymatic changes related to the resistance response against systemic viral infections proved for the first time.

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مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID