Original Article : Association between Exudative Age-related Macular Degeneration and the G6721T Polymorphism of XRCC7 in Outdoor Subjects

( Iraj Saadat ),( Roghayyeh Vakili-ghartavol ),( Majid Farvardin-jahromi ),( Mostafa Saadat ) 대한안과학회 2012 Korean Journal of Ophthalmology Vol.26 No.6

Purpose: To investigate whether the G6721T polymorphism (rs.7003908) of the non-homologous end-joining DNA repair XRCC7 gene contributes to the development of exudative age-related macular degeneration (ARMD). Methods: The present case-control study consisted of 111 patients with exudative ARMD and 112 sex frequency-matched healthy controls that were randomly selected from unrelated volunteers in the same clinic. Genotypes were determined by the Restriction Fragment Length Polymorphism (PCR-RFLP) based method. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ARMD risk associated with polymorphism of XRCC7. In all analysis the GG genotype was considered to be the reference genotype. Results: There was no significant association between genotypes of XRCC7 and susceptibility to ARMD. Considering the significant difference in age distribution between cases and controls, age was used as a covariate in further analysis. After ORs were adjusted for age, the same result was observed. In the next step we stratified our subjects into outdoor and indoor groups according to their job titles. The outdoor and indoor patients were occupationally exposed to sunlight and not exposed to sunlight, respectively. Our present study showed that among indoor subjects there was no association between XRCC7 polymorphism and susceptibility to ARMD. However, among outdoor subjects, the GT + TT genotypes compared to the GG genotype increased the risk of ARMD (OR, 3.13; 95% CI, 1.04-9.39; p = 0.042). Conclusions: Our study revealed that the T allele of the G6721T polymorphism of XRCC7 increased the risk of ARMD among outdoor subjects.

Non-stationary Sparse Fading Channel Estimation for Next Generation Mobile Systems

( Saadat Dehgan ),( Changiz Ghobadi ),( Javad Nourinia ),( Jie Yang ),( Guan Gui ),( Ehsan Mostafapour ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.3

In this paper the problem of massive multiple input multiple output (MIMO) channel estimation with sparsity aware adaptive algorithms for 5^th generation mobile systems is investigated. These channels are shown to be non-stationary along with being sparse. Non-stationarity is a feature that implies channel taps change with time. Up until now most of the adaptive algorithms that have been presented for channel estimation, have only considered sparsity and very few of them have been tested in non-stationary conditions. Therefore we investigate the performance of several newly proposed sparsity aware algorithms in these conditions and finally propose an enhanced version of RZA-LMS/F algorithm with variable threshold namely VT-RZA-LMS/F. The results show that this algorithm has better performance than all other algorithms for the next generation channel estimation problems, especially when the non-stationarity gets high. Overall, in this paper for the first time, we estimate a non-stationary Rayleigh fading channel with sparsity aware algorithms and show that by increasing non-stationarity, the estimation performance declines.

Determination of trace silver in water, wastewater and ore samples using dispersive liquid–liquid microextraction coupled with flame atomic absorption spectrometry

Saadat Rastegarzadeh,Nahid Pourreza,Arash Larki 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-

A fast and reliable dispersive liquid–liquid microextraction (DLLME) method for the determination of trace levels of silver by flame atomic absorption spectrometry (FAAS) was developed. The method is based on highly-efficient separation and preconcentration of silver by the complex formation of Ag(I) with 2-mercaptobenzimidazole and extracted by DLLME procedure using carbon tetrachloride as extraction and acetone as disperser solvent. After establishment of a cloudy solution, the phase separation is achieved and Ag(I) is determined in the enriched phase by FAAS. The method yields a linear calibration curve in the concentration range of 1–100 ng mL1 of Ag(I), and the limit of detection is 0.41 ng mL1. The proposed method was successfully applied to determine the trace amounts of silver in water, radiology film processing wastewater and ore samples.

A Cooperative Use of Stochastic Dynamic Programming and Non-Linear Programming for Optimization of Reservoir Operation

Mohsen Saadat,Keyvan Asghari 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.5

Stochastic Dynamic Programming (SDP) is a conventional procedure to extract optimal reservoir operating policies. SDP appliesexhaustive search based on the total combinations of discrete values of state variables. The accuracy of SDP can be improved byincreasing the number of intervals of inflow or reservoir volume domain; however, increasing the inflow intervals is limited andincreasing the reservoir volume intervals does not guarantee the regular improvement of results. This study attempts to determine thenear optimum discrete reservoir volume values by cooperating SDP and non-linear programming (CSDP) optimization modules, sothe acceptable performance is achieved by limited intervals of the state variables. Towards this end, the objective function is utilizedwith a hedging policy to control the amount of the monthly reservoir release. The non-linear programming optimization moduleembodied in SDP, determines the proper values of reservoir volume taking into account the hedging policy and available constrains. Considering various numbers of inflow and reservoir volume intervals, the conventional SDP results are implemented and comparedto CSDP approach. Our comparisons indicate an improved reliability performance obtained in the CSDP technique. A DistanceBased Interpolation Formula (DBIF) is also illustrated and applied to employ optimal operating polices for reservoir operationmanagement. Findings show better performance of DBIF as compared to conventional methods like Multiple Linear Regression(MLR) during long-time simulation of reservoir operation.

Apolipoprotein E (APOE) Polymorphisms and Susceptibility to Breast Cancer: A Meta-Analysis

Mostafa Saadat 대한암학회 2012 Cancer Research and Treatment Vol.44 No.2

Purpose Apolipoprotein E (APOE, MIM: 107741) has three functionally distinct isoforms of the protein (E2,E3, and E4), encoded by corresponding alleles ε2, ε3, and ε4, which have been well described. Findings from previous studies investigating association between APOE polymorphisms and breast cancer risk have been inconsistent. The present meta-analysis was conducted in order to investigate association of APOE polymorphisms with risk of breast cancer. Materials and Methods Several electronic databases were used for identification of studies containing information on APOE polymorphisms and breast cancer risk published up to January 2012. We identified 10eligible studies, including 3,835 subjects (2008 patients, and 1,827 healthy controls), that reported on polymorphisms of APOE and risk of breast cancer. Summary odds ratios (ORs) and 95%confidence intervals (CIs) were obtained using a fixed and random-effects models. Results Among studies reported from Asia, an association of the ε4 allele with increased risk of breast cancer, in comparison with the ε3 allele, was observed (OR, 1.56; 95% CI, 1.19 to 2.04; p=0.001). It should be noted that allele ε2 showed no association with breast cancer risk. Among Caucasians,neither the ε4 (OR, 0.99; 95% CI, 0.83 to 1.17; p=0.917) nor the ε2 (OR, 0.92; 95% CI, 0.72 to 1.17;p=0.514) allele showed an association with susceptibility to breast cancer, when compared with the ε3 allele. Carriers of the ε4 allele (E4E4, E4E3, and E4E2 genotypes), in comparison with the E3E3 genotype, showed an association with elevated risk of breast cancer only among Asians (OR, 1.75; 95% CI, 1.23 to 2.47; p=0.002). No publication bias was detected. Conclusion This meta-analysis suggest that the APOEε4 allele is a low-penetrant risk factor for development of breast cancer.

MULTI-OBJECTIVE GEOMETRICAL OPTIMIZATIONOF FULL TOROIDAL CVT

M. SAADAT FOUMANI,M. DELKHOSH 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.5

The objective of this research is geometrical and kinematical optimization of full-toroidal continuously variabletransmission (CVT) in order to achieve high power transmission efficiency and low mass. At first, a dynamic analysis isperformed for the system. A computer model is developed to simulate elastohydrodynamic (EHL) contact between disks androller and consequently, calculate CVT efficiency. The validity of EHL model is investigated by comparing output of thismodel and experimental data. Geometrical parameters are obtained by means of Particle Swarm Optimization algorithm, whilethe optimization objective is to maximize CVT efficiency and minimize its mass. The algorithm is run for different values ofselected input parameters that are oil temperature, roller tilting angle (speed ratio). Optimization results show that optimizedgeometrical parameters are approximately constant for various values of input parameters. Also, it is observed that, increasingvalues of oil temperature and roller tilting angle (in clockwise direction), will decrease power transmission efficiency. Anaverage power transmission efficiency of 86.7% is achieved over a wide range of input parameters, using optimized geometry.

Modeling Sorghum Response to Irrigation Water Salinity at Early Growth Stage

Saeed Saadat,Mehdi Homaee 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Comparison of Acellular and Cellular Bioactivity of Poly 3-hydroxybutyrate/hydroxyapatite Nanocomposite and Poly 3-hydroxybutyrate Scaffolds

Abbas Saadat,AliAsghar Behnamghader,Saeed Karbasi,Daryoush Abedi,Masoud Soleimani,Abbas Shafiee 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.3

Nanocomposites have recently been identified as a useful scaffolding material in tissue engineering applications. Poly (3-hydroxybutyrate)/hydroxyapatite nanoparticles (P3HB)/(nHA) porous scaffolds were successfully fabricated through a solvent casting and particulate leaching technique. P3HB/nHA and P3HB scaffolds were prepared by the same technique for comparison. The structure of the nanocomposite and P3HB scaffolds was observed by SEM. The Energy Disperssive X-ray Analysis (EDXA, map of Ca)results indicated that HA nanoparticles were homogeneously dispersed in the P3HB matrix. X-ray diffraction (XRD)analysis showed that P3HB and HA coexist in the nanocomposite. Transmission electron microscopy (TEM)images also showed that the particle size of HA was 30 ~40 nm. The porosity of the scaffolds was 84%, and macropores and micropores coexisted and interconnected throughout the scaffolds. Acellular bioactivity experiments showed that more HA crystals formed on the surface of the nanocomposite scaffold than on the P3HB scaffold after 4weeks immersion in Simulated Body Fluid (SBF). Cell culture experiments demonstrated that the P3HB/nHA nanocomposite scaffold had a better tendency of proliferation and Alkaline Phosphatase (ALP) activity to MG 63 cells than the pure P3HB scaffold. It was found that nHA addition can improve acellular and cellular bioactivity of the P3HB scaffold.

An Account of Null-Prep Constructions in the Interlanguage Grammar of EFL Learners

( M. Saadat ),( F. Sadighi ) 범태평양응용언어학회 2006 범태평양응용언어학회지 Vol.10 No.1

Adsorption of copper ions from aqueous media using montmorillonite-Al2O3 nano-adsorbent incorporated with Fe3O4 for facile separation

Fatemeh Saadat,Mohammad Mahdi Zerafat,Sahar Foorginezhad 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

In the present study, the removal of copper as a common pollutant in industrial wastewaters is considered. For this purpose, montmorillonite (MMT) was doped by Al2O3 nanoparticles via precipitation technique. For immediate separation upon removal, Fe3O4 nanoparticles were incorporated into the as-prepared nanocomposite matrix. The nanocomposite synthesized via co-precipitation is characterized in terms of morphology and structure using SEM, FESEM, EDS and XRD analysis techniques. Also, to verify the magnetic property, value stream mapping (VSM) was performed. To achieve the highest removal rate, effect of parameters such as pH, initial pollutant concentration, amount of adsorbent, temperature and contact time were investigated using Design Expert software. According to the results, at the optimal condition (pH=8.3, pollutant concentration=36 ppm and adsorbent content=77mg), ~99% Cu (II) removal was obtained. Experimental data are well consistent with Langmuir adsorption isotherm which confirms single layer adsorption. To investigate the adsorbent efficiency in continuous cycles, the adsorbent was utilized in five cycles without washing, indicating an acceptable removal percentage without significant plunge.