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Objective: In this study, the possibility of prenatal diagnosis of Down syndrome with Real-Time PCR method was evaluated. In this context, optimization of a suitable method for purification of high quality DNA from amniotic fluid samples was also considered. Materials and Methods: Pregnant women who had the high risk of having babies with Down syndrome were selected according to the biochemical and sonographic data and referred to the amniocentesis center. The DNA of total 59 amniotic fluid samples were extracted with different methods including boiling method, salting out method, Procedures of DNA extraction from Blood and Cell Culture by DNPTM Kit (CinnaGen), Procedure of DNA extraction from cells by DNA Isolation Kit for cells and tissues (Roche), Procedure of DNA extraction from Tissue by MagNa Pure DNA Isolation kit (Roche), and QIAamp DNA Micro Kit (Qiagen). Then, the quality and quantity of the extracted DNA were evaluated by the NanoDrop® ND- 1000 spectrophotometer device. Real-Time PCR reaction using fluorescent dye SYBR Green I (Applied Biosystems, UK) was performed to specifically amplify DSCAM and DYRK1A2 genes and the reference gene (PMP22). Data analysis was performed using comparative cycle threshold method for the determination of the gene dosage and determining the number of copies of chromosome 21. Results: This study showed that DNA extracted from amniotic fluid samples using QIAamp DNA Micro Kit (Qiagen) has the desirable quantity and quality for Real-Time PCR. Specific proliferation of targets and reference genes was achieved and difference between normal and affected groups based on differences between their gene dosages was determined. Conclusion: Prenatal diagnosis of Down syndrome is feasible by the Real-Time PCR method using DNA samples from amniotic fluid cells extracted by QIAamp DNA Micro Kit (Qiagen). The results are comparable to the corresponding results from conventional cytogenetic methods.

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Lost foam casting is a new method for casting complex parts. This method, in addition to its technical and economic advantages over the traditional methods, has environmental benefits and therefore has been of special interest. In this study, the effects of foam density, pouring temperature, and coating viscosity were studied, which are the most important factors affecting porosity and hardness in the lost foam casting method. The Taguchi method, signal to noise ratio and analysis of variance were used to design experiments and determine the optimal levels of each variable. All the considered variables were evaluated in three levels using L9 orthogonal array Taguchi analysis. Results showed that foam density of 20 kg/m3, pouring temperature of 740° C and coating viscosity of 20 sec were the optimal values for the variables due to creating appropriate condition between thermal decomposition and foam evaporation with speed of melting advancement and exhaust gas through the pores in the coating and creating lowest porosity (2.6%) and highest hardness value (27.7 HRA). Foam density and pouring temperature were the most influential parameters on the porosity and hardness with the impact factors of 64.58% and 56.35%, respectively.

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Numerical Investigation of the number of baffles effect on the efficiency of primary sedimentation tank in true dimensions.
Settling tanks of wastewater treatment plants are the most important components so that about one-third of the cost of a wastewater treatment plant construction is concerned to these tanks. In addition, the regulations referred to design of settling tanks are not enough. According to these, the adverse factors in settling tanks is very important to design and improve their performance. These factors in primary sedimentation tanks are including circulation zones, the phenomenon of short circuiting and non-uniform flow. One of the most important ways to improve flow conditions and increase the efficiency of settling tanks, is modifying the geometry of the tank through the installation of baffles. In this investigation, the effect of baffle structures on the hydraulic efficiency of primary sedimentation tanks has been investigated by three-dimensional numerical modeling in Flow-3D software. In this study, the optimum number of baffles is studied to increase hydraulic efficiency. Settling tank in true size and simplified model primary settling tank treatment plant south of Tehran. The geometry Specifications of tank include of length tank (L) from the main inlet to the overflow output of 60 m, a width of tank (W) 12.9 m, water depth in normal mode (H) 3 m. the input flow rate to the tank 650 l/s. Model geometry using AutoCAD software and three-dimensional shape is drawn. In this study, from three mesh blocks to mesh geometry model is used. All three of these blocks in all directions are fully in touch with and the type of are linked blocks. Intended for three blocks, the size of the mesh is selected respectively, 5, 7 and 10 cm monotonically in each direction. In numerical modeling, the turbulence model used to solve turbulent flow and to solve pressure the GMRES method is used. In addition, the VOF technique to show the behavior of fluid on free surface flow and FAVOR technique have been used to simulate surfaces and geometric boundaries. Verification of numerical simulation results with former experimental data properly acknowledges the numerical results. It is already known the optimal location of the first baffle.
The results show that baffle causes the uniformity flow and increase removal efficiency of the primary sedimentation tanks. To determine the optimum number of baffles, the comparison results between no baffle tank and optimized cases with one, two and three baffle done. Using more baffles, in ideal conditions, causes suppression of the jet flow and more chances the suspended particles deposition. The addition of new baffles in suitable locations reduces the maximum velocity amount, the size of the circulation zones and kinetic energy and create uniform velocity vectors inside the settling zone. Volume circulation zones by using one, two and three baffles compared to non-baffle decreased 4.18, 4.44 and 4.56% of the total tank volume, respectively. Finally, the results of the FTC method for several cases indicated that using number of baffles lead to increasing the performance of the sedimentation tanks.

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Life table parameters of the bird cherry-oat aphid, Rhopalosiphum padi (L.) were determined on different barley (Hordeum vulgare L.) varieties. Experiments were carried out under laboratory condition of 26­±­1ºC, 65­±­5% RH and photoperiod of 16­:­8 (L­:­D) hours. Newborn first instar nymphs of the same age were reared on the leaves of six barley varieties using leaf cages. Nymphal development time, mortality, longevity and adult fecundity were recorded daily. Nymphal survivorship varied from 71% to 88% on the varieties tested. The results revealed significant effect of experimental varieties on demographic statistics of R. padi. The intrinsic rate of natural increase r_m, ranged between 0.318 and 0.366 female/­female/­day; the range of other life table parameters was from 1.37 to 1.44 day^-1 for finite rate of increase λ, 43.83 to 60.65 female­/female­/­generation for net Reproductive rate R₀,1.89 to 2.17 days for Doubling Time DT and 11.19 to 11.86 days for mean generation Time T. In conclusion, analysis of biological parameters indicated Valfajr and Fajr30 as relatively less susceptible varieties to R. padi, while Reihan­03, Kavir and Zarjow were considered as relatively more susceptible and Nosrat was placed in the same statistical group with other varieties.