Showing 9 results for Hassanlou
Volume 1, Issue 1 (3-2012)
Abstract
The entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. is one of the important arthropod pathogens that can play an important role in the regulation of mite populations in agricultural ecosystems. In this study, the combined effect of a native isolate of fungus B. bassiana (EUT105) and ether-extract of plant, Ginkgo biloba was evaluated against the two-spotted spider mite, Tetranychus urticae Koch. At first, effect of three concentrations 5, 10 and 20% of G. biloba was evaluated on B. bassiana conidial germination and mycelial growth. Then, potential synergism between B. bassiana and G. biloba was investigated in order to incorporate both in the control of this pest. Only the 20% concentration of plant extract had significantly inhibitive effect on germination and mycelial growth. The mortality of adult female T. urticae increased significantly when B. bassiana was applied with 5 and 10% concentrations of G. biloba extract. Hence, there is a synergistic effect between this native B. bassiana and ether-extract of G. biloba in controlling the two-spotted spider mite.
Volume 3, Issue 2 (6-2014)
Abstract
The aphid species, Cinara pini (Linnaeus, 1758) reported in our previous work as a new aphid on pinus trees for Iran, was described using the classic method and through analysis of COI gene sequence. In the next step, we addressed the efficiency of the entomopathogenic fungus, Lecanicillium longisporum (Zimm.) Zare and Gams strain LRC 190, on the aphid. The fungus was administered to the second instar nymphs and adults using topical application procedure. The results indicated that the entomopathogen caused 90% mortality in adults over seven days at a concentration of 108 spores/ml, while the same control level was achieved for nymphs by 8 × 107 spores/ml. The LC50 values were obtained as 1.2 × 106 and 6.9 × 105 spores/ml for adults and nymphs, respectively. The present study suggests that the entomopathogenic fungus, L. longisporum could be considered as a potential candidate in biocontrol programs of C. pini. This is the first report on the pathogenicity of L. longisporum on C. pini.
Volume 3, Issue 4 (12-2014)
Abstract
Entomopathogenic fungi produce a variety of degrading enzymes, including proteases, chitinases and lipases, to facilitate their entry through the massive barriers of insect cuticle. Isolates of the entomopathogenic fungi vary considerably in their proteolytic activity and virulence. The proteolytic activity of different isolates has been hypothesized to reflect their virulence toward the host. In this study, we evaluated the virulence and proteolytic activity of 17 Beauveria bassiana sensu lato isolates collected from different geographical regions in Iran. The selective medium D0C2 was used for isolating B. bassiana from soil samples. Casein substrate was used for protease assay. Total mortalities caused by different B. bassiana isolates through the dipping method, ranged from 25 to 60% with the highest and lowest rates for isolates BA and MITE, respectively. Our results revealed a wide variation in both proteolytic activity and virulence among the studied isolates. Additionally, we found a strong positive correlation between the proteolytic activity on Casein substrate and virulence of the isolates against the Khapra beetle, Trogoderma granarium. This finding will facilitate the screening and selection process of virulent fungal isolates as efficient agents for use in biological control programs of insect pests.
Volume 4, Issue 3 (9-2015)
Abstract
Effects of three nutritional levels of beet root molasses, cheese permeate, wheat bran extract, rice bran extract and Sabouraud,s Dextrose Broth (SDB) were evaluated for blastospore production by two isolates of Beauveria bassiana sensu lato. at an interval of 24 h for seven days. Depending on the isolate, maximum blastospore production was obtained in 12% rice bran extract and 20% cheese permeates on the 7th day. Both isolates produced the fewest blastospores in 4% cheese permeate. Virulence of blastospores, produced in liquid media containing beet root molasses, permeate, wheat bran extract and SDB (as control), on third instar larvae of brown tail moth Euproctis chrysorrhoea indicated that there were no significant differences among these nutritional media for either one of the isolates. Considering blastospore quantity and quality in terms of virulence and local accessibility, cheese permeate was found to be the best medium for mass production of B. bassiana blastospores.
Volume 7, Issue 2 (9-2016)
Abstract
Neurotrophins are a family of secretive growth factors that do their functions via binding to their specific receptors (Trks) or their common receptor (p75ntr). p75ntr has important roles in survival, differentiation and proliferation of several types of cells. MicroRNAs are non-coding small RNAs that regulate post-transcriptional mRNA expression. Recently, a MiRNA named hsa-miR-6165 has been discovered in forth intron of p75ntr. Bioinformatics analysis has revealed that this MiRNA has important roles on regulation of several cellular signaling pathways and signaling pathway involve in differentiation. Therefore, in the present study, the expression of hsa-miR-6165 in neuronal differentiation of NT2 human embryonic carcinoma stem cell line and non-nervous and nervous human cell lines was analyzed. Our results indicated that hsa-miR-6165 not only has been expressed in differentiation process of NT2 cells and neural cell lines but although significantly expressed in several human non-neural cell lines such as hFSF and Hela. In addition, the expression of this miRNA, unlike its host gene, upregulated at the end of the differentiation. These results indicate the probable presence of independent promoter for this MiRNA and revealed that hsa-mir-6165 maybe has roles in cellular differentiation which needs more investigation.
Volume 9, Issue 4 (8-2020)
Abstract
In the present study, the cuticle-degrading enzymes production potential of five native Beauveria bassiana (TV, OZ, UN, DV and DE) isolates was investigated in the presence of cuticles from Eurygaster integriceps, Ephestia kuehniella and Zophobas morio. Furthermore, histopathology of infected insects by B. bassiana was studied. The level of cuticle degrading enzymes was the highest and lowest for TV (as the most virulent isolate) and DE (as the weakest isolate), respectively. E. integriceps nymphs as the most sensitive host produced the highest level of cuticle degrading enzymes (Pr2, exochitinase, and lipase) while Z. morio as the most resistant host, produced the lowest level of hydrolytic enzymes. According to histopathological study, the fungal isolate could not penetrate into Z. morio cuticle, as no mycelia or hyphae were observed in its tissues after inoculation, while fungal bodies were detected in microscopic slides of the other two insects. Overall, the chemical and topographical structure of insect cuticle had a substantial effect on the virulence of entomopathogenic fungus. Production of enzymes including proteases (especially Pr2), chitinase (N-acetyl-glucosaminidase), and lipases was positively related to virulence of fungus isolates. It can be concluded that not only the hydrolytic activity of B. bassiana isolates, but also host cuticle composition determine the pathogenesis and virulence cascade in fungus-insect interactions.
Volume 13, Issue 3 (1-2023)
Abstract
Ras signaling is an important intracellular signaling pathway that is key regulator of several aspects of normal cell growth and malignant transformation. The RAS gene family consists of three small G proteins; H-Ras, N-Ras, and K-Ras that play a central role in cell signaling for growth, proliferation, and migration. Mutation of the Ras oncogenes creates the malignant properties that are needed for cancer to grow and spread. MicroRNAs (miRNAs) that are encoded within the Ras genes might also have roles in cancer development. Here, novel microRNAs located in the human N-Ras gene were bioinformatically predicted. SSC profiler program was utilized to predict the stem-loop structures within the genomic area of interest. UCSC genome browser database was useed to analyze the conservation status of the putative miRNA and its precursor sequence. Furthermore, the N-Ras-miRs prediction was also performed by using MatureBayes online tool. In addition, RNAFOLD online software which applies the minimum-free energy (MFE) RNA structure prediction algorithm, was used for approximate prediction of the stem-loop structure. Our results demonstrate that N-Ras with about 5Kb length has some predicted miRNA stem-loop-like structures that have relatively conserved sequences. Overall, accumulative pieces of evidence indicated the presence of novel miRNAs encoded within the N-Ras oncogene.
Volume 21, Issue 2 (5-2021)
Abstract
The interaction between soil and geosynthetics has great importance in engineering work, especially in design and stability analysis of geosynthetic-reinforced geotechnical structures. In recent decades, several laboratory methods have been performed to properly understand the interaction between soil and geogrids, including pullout test, large-scale direct shear test. Although factors such as the geometry of the reinforced soil system and its construction process may affect the interaction properties between the soil and the geosynthetic, these properties are strongly influenced by the physical and mechanical properties of the soil and the geometrical and mechanical properties of the geosynthetic. Pullout test determines the geosynthetic pullout resistance, which is an important design parameter in relation to the internal stability of geosynthetic-reinforced geotechnical structures, and allows the measurement of displacements throughout the specimen during the pullout testing. Pullout force refers to the tensile force required to create an external sliding of geogrid embedded in soil mass. The tensile strength of the reinforcement consists of the frictional resistance on the surface of the longitudinal and transverse members of the geogrid and the passive resistance that is mobilized against the transverse members. Although fine-grained soil is recommended in the design of geosynthetic-reinforced soil structures, many geosynthetic-reinforced soil structures are constructed using soil containing a fine percentage. Therefore it is important to investigate the effect of fine grains on the stability and performance of such soil structures under different loading conditions. Geosynthetic-reinforced soil structures are sometimes affected by cyclic loads due to traffic and train crossings, vibration of industrial machinery, wave and earthquake. In this study, by performing static and multistage pullout tests, the static and post-cyclic pullout behavior of a uniaxial geogrid manufactured in Iran under the brand GPGRID80/30 is presented. The tests were carried out on a large scale pullout box with a dimension of 90 × 50 × 50 cm and with a constant rate and multi-stage procedures on three different soil types including clean sand, sand containing 10 and 20% fine silt and three effective vertical stresses of 20, 40 and 60 kPa. Results show that geogrid static pullout resistance increases with increasing effective vertical stress in all three different soil types. Also, the increase of silt in the sandy soil resulted in an increase in the monotonic maximum pullout resistance at effective stress of 20 kPa. The geogrid behavior in all three soils for 20 kPa vertical effective stress was strain softening and for the 40 and 60 kPa vertical effective stress the geogrid pullout behavior was strain hardening. However, 10% increase in silt content leads to a slight decrease in monotonic pullout resistance and a 20% increase resulted the slight increase in monotonic pullout resistance of geogrid at vertical stress of 40 and 60 kPa. As the amount of silt content increased, the effect of cyclic loading on post-cyclic resistance increased, especially in vertical effective stresses of 40 and 60 kPa. Also, at effective stress of 20 kPa, the geogrid post-cyclic resistance decreased in all three sands, sand containing 10% silt and sand containing 20% silt relative to its corresponding monotonic pullout resistance.
Volume 23, Issue 3 (Summer 2020)
Abstract
Aims: Living cells have an electrical charge created by the presence of ions and free radicals. Magnetic fields interact with ions, especially ferromagnetic materials such as iron that affect living cells. A common feature of about 20 different diseases is the aggregation of proteins in the form amyloid structure. In the current study, the effect of static magnetic field (SMF) on the formation and the toxicity of amyloid structures was investigated.
Materials & Methods: CHO cells were exposed to 6mT SMF in three consecutive days, and the effect of SMF on the formation of amyloid structures in the intrinsic proteins of these cells related to the control was investigated using thioflavin T (ThT) binding assay. The formation of amyloid structures in CHO cells expressing human ProIAPP cells was analyzed by observation of proIAPP protein aggregates linked to GFP protein. The effect of SMF on the toxicity of lysozyme oligomers on CHO and Hela cells was also compared with the controls.
Findings: Exposure of CHO cells to magnetic fields does not have a significant effect on the formation of amyloid structures in the intrinsic proteins of CHO cells and the amount of these structures in CHO cells expressing proIAPP protein but can increase the toxicity of lysozyme oligomers on CHO and Hela cells.
Conclusion: The magnetic field does not have a significant effect on the formation of amyloid structures in the 6mT SMF strength, but it adds to the toxicity of these structures.
