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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Progress in Biological Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Drought stress,Salicylic acid,MDA,Antioxidative enzymes,Aloysia citrodora
- چکیده:
- چکیده انگلیسی: Lippia citriodora H.B.K. is a valuable medicinal plant of Verbenaceae family. This study was calculated to evaluate potential role of salicylic acid (SA) in diminish the harmful effects of drought stress on L. citriodora plants. SA (0.5 and 1 mM) was used to L. citriodora plants grown under stressed (5, 10, 15 and 20% PEG) and unstressed conditions. Fresh weight (FW) and relative water content (RWC) significantly decreased under water deficit stress. Increase in hydrogen peroxide (H2O2) and malondialdehyde (MDA) content indicated drought-induced oxidative stress in L. citriodora. Water deficit stress significantly increased the protein content, proline content and antioxidative enzymes activities. The exogenous application of SA to drought-stressed plants reduced the content of MDA and H2O2 and increased superoxide dismutase (SOD), peroxidase (POX) and chlorophyll content. It is suggested that SA minimizes the negative effects of drought stress and could be used for amelioration of drought stress in L. citriodora.
- انتشار مقاله: 11-06-1398
- نویسندگان: Behnam Mohammadi,Maryam Rezayian,Hassan Ebrahimzadeh,Javad Hadian,Masoud Mirmasoumi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Plant Physiology
- نوع مقاله: Journal Article
- کلمات کلیدی: Antioxidants,Stress,reactive oxygen species,Tolerance,mitigation strategies,Cyanobacteria
- چکیده:
- چکیده انگلیسی: Cyanobacteria are an important source of natural products. In this article, we briefly review the responses of cyanobacteria to different stresses. Abiotic stresses (temperature, salt, heavy metals, metalloid and ultraviolet (UV) influence cell growth and metabolism in cyanobacteria. Salt stress is a major abiotic factor that decreases the growth of cyanobacteria and affects the different processes including photosynthesis, respiration, and metabolism. The basic mechanisms for salinity adaptation include the active extrusion of inorganic ions and the accumulation of compatible solutes such as sucrose, trehalose, glucosyl glycerol, and glycine betaine. Cyanobacteria have a complex antioxidative system including enzymatic and nonenzymatic antioxidants for mitigation of oxidative damage under salt stress. Cyanobacteria have some defense mechanisms for the decline of the direct and indirect destructive effects of UV. These mechanisms include avoidance, scavenging of reactive oxygen species (ROS), synthesis of UV-absorbing/screening compounds such as mycosporine-like amino acids and scytonemin, repair of UV-induced damage in DNA, and resynthesis of proteins. Metals are involved in key metabolic pathways as redox cofactors in proteins. High concentration of metals causes the generation of ROS and oxidative damage. Thus, the major role of metal homeostasis in maintaining the intracellular concentration of metal within a range compatible with cell viability becomes evident. The biosynthesis of metabolites can be triggered by a number of abiotic stresses because they affect metabolic pathways.
- انتشار مقاله: 14-05-1398
- نویسندگان: Maryam Rezayian,Vahid Niknam,Hassan Ebrahimzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Droplet dispersion,Eddy Interaction Model (EIM),Reynolds Stress Transport Model (RSTM),Enhanced wall treatment,Curved type vane separator
- چکیده:
- چکیده انگلیسی: In this paper, the turbulent air droplet flow inside a single passage of a curved type vane separator has been studied numerically. The simulation is based on the Eulerian - Lagrangian method. For turbulent air flow calculations, a computer code was developed to solve the Reynolds Averaged Navier Stokes (RANS) equations together with the equations of Reynolds Stress Transport Model (RSTM) on collocated unstructured meshes. Finite volume method was applied for discretization of the gas flow equations. Also, the low Reynolds modification has been applied for RSTM and the results have been compared with those obtained by Standard RSTM. For droplet trajectory calculation, the Eddy Interaction Model (EIM) was applied to take the turbulent dispersion of droplets into account. The performance of the code has been evaluated by comparing the simulations results with experimental data. The results show that by including the wall reflection terms in transport equations of the Reynolds stresses, better predictions can be achieved than those obtained by RSTM without wall reflection terms. The enhanced wall treatments can further improve the results. Finally, the pressure loss and droplet removal efficiency for different plate spacings have been calculated using the developed codes. The numerical results show that for plate spacings in the range of 25 mm to 35 mm, the pressure loss is approximately constant. On the other hand, the increment in plate spacing reduces the droplet removal efficiency. Therefore, in the mentioned range, 25mm spacing gives the best performance for this type of the vane separator.
- انتشار مقاله: 16-08-1388
- نویسندگان: Roohollah Rafee,Hassan Rahimzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Pediatrics
- نوع مقاله: Journal Article
- کلمات کلیدی: risk factors,Pregnancy,Infant,fetus,Prenatal care,Premature
- چکیده:
- چکیده انگلیسی: Background: Preterm birth is one of the most remarkable reasons for neonatal and infant mortality and morbidity across the world. This study aimed to determine risk factors of premature infants in the rural area of Azadshahr city, Iran. Materials and Methods: Acase-control study was conducted on all premature and low birth neonates (less than 37 weeks and weight less than 2500 grams). Data were collected by records in 30 health houses located in the rural areas of Azadshahr city durring 2013 to 2016. Two groups (case and control) were matched by gender and health houses. A trained midwife was collected data by using of a researcher-made checklist. To describe mean and standard deviation of the demographic characteristics, descriptive methods were used.To analyze, inferential statistic tests such as Chi- square, and independent t-test were implemented through SPSS (version,16). Significant level was also taken <0.05. Results: In total, 112 girl infant and 101 boy infant were explored. The mean age of mother in the case and control groups was 26.14+ 8.4 and 25.67+ 9.1 years old respectively.There was a significant difference between the two groups in terms of prenatal care and pregnancy complications. In addition, a remarkable relations was found between polytocous and delivery time (P<0.05). Conclusion: Providing mothers with necessary information in terms of interval between births, and the importance of prenatal cares in the pregnancy period to prevent complication seems to be likely useful.
- انتشار مقاله: 30-03-1395
- نویسندگان: Marzieh Gorzin,Morteza Mansourian,Abdurrahman Charkazi,Hassan Rahimzadeh,Aref Rezaee Node,Mostafa Qorbani,Omid Safari,Babak Rastgari Mehr,Hamid Asayesh,Mohammadreza Mansouri Arani,Hossein Ansari,Tahereh Pashaei,Hesamedin Hesamedin Askari Majdabadi,Kamal Mirkarimi
- مشاهده