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In order to investigate different treatment effects on germination in Gundelia tournefortii, three factorial experiments were carried out in the completely randomized design with three replications. The first factor was stratification at 4^oC in three levels including 0, 3 and 6 weeks, the second factor was mechanical scarification in two levels including seeds with/without scarification and the third factor was chemical treatments of seed dormancy breaking in three levels including distilled water and gibberellic acid at concentrations of 1000 and 1500 mg/l and Thiourea 0.1%. The results showed that the effects of stratification, scarification and chemical treatments of dormancy breaking and their interactions were significant on all studied parameters (p<0.01). Mean comparison values were significant for the effects of spate treatments together with mechanical scarification for the improvement of all traits. The results also revealed that treatment of mechanical scarification treatment together with gibberellic acid 1000 mg/l in six weeks stratification, due to maximum germination speed, seedling dry weight, seedling length, large-scale germination percentage and seedling vigor index and modest average germination period, was the most influential treatment for seed dormancy breaking of this plant. Correlation between germination percentage with germination rate, dry weight and seedling length was significant. It seems that seed dormancy type in Gundelia tournefortii is physiological and physical, as eliminating physiological and physical factors leads to its germination improvement.
 

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Gentamicin (GM) is an antibiotic widely used against gram-negative infections. However, its clinical application is limited due to its nephrotoxicity. Oxidative stress plays an important role in the nephrotoxicity of gentamicin. Previous studies showed that Rosa canina L. (RC) fruits possess antioxidant, antimutagenic and anticarcinogenic effect. The aim of this study was to investigate the protective effect of RC on GM-induced nephrotoxicity in rats. Thirty male Wistar rats were divided into five groups and treated as follows: Group 1 (control group) was treated by the oral administration of 1 ml normal saline, Group 2 was treated by a 100 mg/Kg (B.W) dose of GM intraperitoneally, Group 3 was treated by oral administration of 200 mg/Kg (B.W) of RC followed by a 100 mg/Kg (B.W) dose of GM intraperitoneally, Group 4 was treated by oral administration of 400 mg/Kg (B.W) RC followed by a 100 mg/Kg (B.W) of GM intraperitoneally, and Group 5 was treated by oral administration of 400 mg/Kg (B.W) of RC. The nephrotoxicity observed in each group was histopathologically evaluated by light microscopy and biochemically evaluated by measuring the levels of creatinine and urea in the blood serum. The relative weight of kidney in each gentamicin-treated animals in the group 2 was increased in comparison with those in the control group (p<0.05), however, the administration of RC extract decreased the kidney somatic index toward the normal level. While the animals treated with gentamicin showed significantly higher levels of serum urea and creatinine (p<0.001), simultaneous coadministration of GM with a high dose of RC (400 mg/Kg (B.W) ameliorated the biochemical indices of nephrotoxicity, showing the significant decrease in the levels of serum creatinine and urea. In addition, Histomorphological examination showed that the rats treated with GM suffered necrosis and desquamation of tubular epithelial cells, glomerular stasis and inflammatory cell infiltration in renal cortex, while simultaneous administration of RC and GM reduced those histologically damages. It could be concluded that the administration of RC showed a protective effect on the rat kidney by preventing renal damages induced by GM, therefore, the RC-based supplements could be proposed to minimize the GM-induced renal damages.
 

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Centaurea glastifolia, a plant species from the Asteraceae family, is distributed in the Northwest of Iran. This study carried out to determine suitable habitats and habitat connectivity of Centaurea glastifolia in three Provinces of West Azarbayejan, East Azarbayejan and Ardabil. Seven habitat variables and 36 presence points were selected for habitat modelling using six habitat distribution models of GLM, GAM, MARS, MaxEnt, RF and GBM. The ensemble map resulting from these models was used for habitat connectivity modelling using electrical-circuit method. Results of habitat evaluation revealed that suitable habitats of the species studied were mainly located in West Azarbayejan and east of Ardabil Provinces, for which distance from agricultural lands, mean annual temperature and distance from rangelands had the highest contribution to the model. Habitat connectivity modelling showed that the current density movement was highest in West Azarbayejan. Current density movement between East and Southeast of Ardabil was evaluated to be significant, whereas the current density movement between West Azarbayejan and Ardabil Provinces was relatively low. The high current density movement in West Azarbayejan indicates the species’ high dispersal ability in expanding its range across the area. The results of the current study could facilitate understanding of the distribution and dispersal of Centaurea glastifolia.
 
 

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Biological cementation is a new process in which urea hydrolysis bacteria or free urease enzyme decompose urea and increases the pH of the environment and chemical interactions in the presence of calcium ions to form calcite. Nowadays, nano-calcite is widely used in engineering, such as increasing the strength of soil and concrete, as well as in medicine, such as drug delivery and cancer treatment. This study aimed to investigate the laboratory conditions for producing nano-calcite particles with appropriate quality, size and purity by Sporosarcina pasteurii enzyme extract for use in medical and engineering studies. This investigation aimed to make calcite by S. pasteurii enzyme extract and optimize influential factors in calcite production. For this purpose, the bacterium S. pasteurii was cultured in nutrient broth containing urea and nickel, and upon reaching the appropriate time, the cells were separated and washed. Then, their enzyme extract was prepared by sonication, and calcite precipitation was studied in different amounts of urea, calcium chloride, enzyme and temperature. The quality of produced calcite crystals and their ratio compared to other crystals were investigated by XRD and SEM analyses. According to the results of XRD analysis, it was found that in 0.5 M urea and 0.25 M calcium chloride, the highest amount of calcite is produced with 96%, and the least side products are produced. Examining the particle size histogram in the sample containing 0.5 M urea and 0.25 M calcium chloride revealed that the range of particles were between 50 and 100 nm. The nature and type of crystals were studied by electron microscopy, and EDX analysis showed the presence of calcium, oxygen, and carbon. According to the results, it was found that by the increase of the concentrations of urea and calcium, the range of particle size became larger. Also, the percentage of calcite produced in low urea and calcium chloride concentrations is higher than those in high concentrations.