Showing 7 results for Ramezanpour
Volume 2, Issue 1 (6-2013)
Abstract
Cell concentrations and growth rate of Dunaliella salina Teodoresco in light intensities e. g. 50 and 150 µmol. photons.m-2.s-1 and temperatures 25 ± 0.5 and 31 ± 0.5 oC (Mean ± SD) were studied. The algae was isolated from the Urumieh Lake and cultured in various treatments (n=12). Algae cells were counted regularly using Thoma counting chamber in 3 replicates on daily basis. The curve of changes in population was plotted. The specific growth rate (SGR; d-1) was calculated and compared within treatments by means of two ways ANOVA Analysis. The highest cell concentration (Mean ± SD) 4.8 ± 0.6 × 10 6 cell.ml-1 was observed in light intensity of 150 µmol. photons.m-2.s-1 and temperature 25 ± 0.5 oC. The minimum cell concentration (2.8 ± 0.3 × 10 6 cell.ml-1) was observed in light intensity of 50 µmol. photons.m-2.s-1 and temperature 31 ± 0.5 oC. Specific growth rate showed significant differences in various treatments (P
Volume 6, Issue 4 (12-2017)
Abstract
The thermophilic fungus Mycothermus thermophilus is one of the most important thermophilic fungi in mushroom composting process. Thirty nine isolates of M. thermophilus were collected from nine provinces of Iran and were identified as M. thermophilus based on morphological features and ITS regions. The studied isolates significantly increased the growth of Agaricus bisporus hyphae compared to control when used in vitro situation. Also the colony morphology of the mushroom changed when it grew on the colony of M. thermophilus. While the studied thermophilic isolates were morphologically different, no diversity was observed in terms of Random Amplified Polymorphic DNA (RAPD) finger-printing. The genetically clonal population of M. thermophilus collected from Iranian mushroom composting farms was attributed to lack of sexual reproduction, similar raw materials used in compost formulations, compost temperature, and concentration of ammonia during pasteurization as selection pressures.
Volume 9, Issue 4 (Fall 2018)
Abstract
Aims: Carotenoids are pigments widely used in the food industry. The aim of this study was to evaluate the antimicrobial effect of pigment extracted from Micrococcus roseus.
Materials and Methods: In this experimental study, Micrococcus roseus cells were settled by centrifugation, and 10ml acetone was added and they were homogenized by homogenizer. Then, homogenized suspension was centrifuged, the supernatant was collected, and carotenoid pigments were extracted with equal volume of petroleum ether. After filtration of pigmented solution, the solution was concentrated by rotary evaporator and, then, it was converted to powder by freeze dryer. Antimicrobial activity was evaluated by disc diffusion method and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, using the agar dilution method. For statistical analysis, Tukey test and Minitab 16 statistical software were used.
Findings: Pigment extracted from Micrococcus roseus influenced the growth of all tested bacteria; Bacillus cereus and Salmonella enteritidis had the highest (12.4mm) and lowest (10.9mm) sensitivity, respectively, to pigment extracted from Micrococcus roseus in 5mg. Salmonella enteritidis had the highest MIC (64mg/mL) between the tested bacteria, but MBC was not observed for Salmonella enteritidis at the tested pigment extracted from Micrococcus roseus concentrations. The antimicrobial effect of extracted pigment on gram-positive bacteria was higher than gram-negative bacteria.
Conclusion: The extracted pigment from Micrococcus roseus is natural and has antimicrobial activity. The antimicrobial effect of extracted pigment on gram-positive bacteria is higher than gram-negative bacteria.
Volume 12, Issue 1 (Winter 2024)
Abstract
Aims: This study aimed to evaluate the impact of virtual Doughnut educational rounds on learning levels and satisfaction among nursing students in the operating room setting.
Materials & Methods: This quasi-experimental study with a pre-test-post-test design involved 70 undergraduate nursing students specializing in operating room practices, selected through a census approach. Participants were randomly allocated into two groups: one receiving instruction via online lectures and the other through virtual Doughnut educational rounds. The educational material was delivered to the first group using the virtual Doughnut round method and to the second group through online lectures. Data were gathered and analyzed using SPSS software version 19, employing descriptive statistics, t-tests, analysis of covariance, and the Mann-Whitney test.
Findings: The pre-test scores did not show a statistically significant difference between students taught by online lectures and those taught by virtual Doughnut educational rounds (p-value=0.538). However, t-test analysis indicated that the Doughnut round method was more effective than traditional lectures, with students showing significantly greater satisfaction with the Doughnut round approach (p<0.0001).
Conclusion: The virtual Doughnut round method is more effective than traditional lectures for teaching operating room nursing students, particularly those in their senior year.
Volume 14, Issue 7 (Supplementary Issue - 2012)
Abstract
All of the tea plantations in Iran are concentrated in the Caspian Sea region on soils previously developed under deciduous natural forests. This research conducted to study the effect of land use change (from forest to tea) on selected physico-chemical and mineralogical properties of soils under humid climate and mountainous landscape in Northern Iran. Three transects facing west to northwest in both tea plantation and the nearby natural forest were selected. A total of 18 soil profiles formed on different physiographic positions i.e. summit, shoulder and foot slope were studied and morphological features of the soils were described. Soil samples taken from each horizon were analyzed. A two factor completely randomized design was used to take soil samples from surface horizons in each transect. Results showed that after changing forest to tea cultivation pH, cation exchange capacity, clay content and the amount of organic carbon of the soils were decreased at P< 0.01 significance level, but bulk density was increased compared to soils under natural forest. X-ray diffractograms of clay fractions showed that vermiculite, vermiculite–illite mixed layers and hydroxy interlayered clay minerals were the major clay components. Soils under tea cultivation possessed highly developed and more prominent argillic horizons and contained more clay fraction in the lower horizons in all physiographic positions.
Mehdi Ramezanpour, Mehdi Maerefat, Manijhe Mokhtari-Dizaji,
Volume 15, Issue 5 (7-2015)
Abstract
Compliance mismatch is one of the reasons of the coronary artery bypass graft (CABG) failure. The purpose of this study is to investigate the effect of compliance mismatch on the End to Side bypass graft. In order to model non Newtonian behavior of the blood flow, the Carreau–Yasuda model was employed and the graft and artery wall was assumed to be isotropic and modeled as a linearly elastic. In this study also the effects of blood rheology and wall distensibility on the wall shear stress distribution and velocity profile were investigated. The results of the simulation show that the maximum deformation occurs in the critical position of graft-artery junction and compliance mismatch cause smaller wall deformation in comparison to the cases in which the materials of the graft and artery are the same which leads to a higher intramural shear stress in graft-artery junction. The anastomotic wall deforms in a way that always tends to separate the graft and artery. Wall shear stress distribution on the bed centerline and the toe of the bypass graft indicates that the differences between the homologous and non-homologous material case are visible only when the internal pressure is lower than the external one. In the distal location of the artery after the toe of the anastomotic, the values of wall shear stress in the homologous material case are lower than the non-homologous material one.
Volume 17, Issue 3 (5-2015)
Abstract
In this study, accumulation of H2O2, malondialdehyde (MDA) (as cold-induced oxidative stress indicators), the transcript levels of dehydrin and beta-glucosidase genes (involved in metabolic responses) was evaluated in chickpea cv. Jam, using qRT-PCR during control, cold acclimation (CA), cold stress (CS), recovery, and freezing phases. Results showed the existence of wide range of genetic capacity in the cultivar to increase cold tolerance when environmental conditions change. Significant increase in H2O2 and MDA content during CA phase indicated that seedlings perceived cold signaling that resulted in remarkable increase in the transcript levels of dehydrin and beta-glucosidase genes as part of defense responses of plants. Balancing the expression of these genes and oxidative stress indicators showed the interplay between two major defense and injury pathways. During freezing phase, the higher transcript levels of these genes in acclimated plants compared to non-acclimated plants showed a more active role for plant cells. An incapability of defense machine in non-acclimated plants was a limiting factor determining the low potential of chickpea plants to freezing phase. It was suggested that adjustment and metabolic alterations like dehydrin and beta-glucosidase genes, especially after CA phase and, thereby, decrease in oxidative stress indicators, could be a reason for relative cold tolerance in chickpea.
