DFT/B3LYP Study to Investigate the Possible Ways for the Synthesize of Antioxidants with High Efficiency Based on Vitamin E

Najafi, Meysam,Najafi, Mohammad,Najafi, Houshang Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

The possible ways for increasing the antioxidant properties of vitamin E have been investigated with density function theory. The effect of replacing three methyl groups of vitamin E with various substituents such as electron donating and electron withdrawing groups on the antioxidant properties of vitamin E were investigated. Also the effects of the reducing the number of atoms in the heterocyclic ring and replacing the oxygen heteroatom with other heteroatoms on the antioxidant properties of vitamin E were investigated. The novel structures that obtained from replacing methyl groups with substituents such as $NH_2$, OH, COOH and NHMe have greater antioxidant activity than vitamin E. Obtained results reveal that novel structure that obtained with replacing O with NH hetroatom would be a better antioxidant than vitamin E. The results reveal that reducing the number of atoms in the heterocyclic ring is a better way to synthesize novel antioxidants.

DFT/B3LYP Study of the Substituent Effects on the Reaction Enthalpies of the Antioxidant Mechanisms of Magnolol Derivatives in the Gas-Phase and Water

Najafi, Meysam,Najafi, Mohammad,Najafi, Houshang Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

In this paper, the study of various ortho- and meta-substituted Magnolol derivatives is presented. The reaction enthalpies related to three antioxidant action mechanisms HAT, SET-PT and SPLET for substituted Magnolols have been calculated using DFT/B3LYP method in gas-phase and water. Calculated results show that electron-withdrawing substituents increase the bond dissociation enthalpy (BDE), ionization potential (IP) and oxidation/reduction enthalpy (O/RE), while electron-donating ones cause a rise in the proton dissociation enthalpy (PDE) and proton affinity (PA). In ortho- position, substituents show larger effect on reaction enthalpies than in meta-position. In comparison to gas-phase, water attenuates the substituent effect on all reaction enthalpies. In gas-phase, BDEs are lower than PAs and IPs, i.e. HAT represents the thermodynamically preferred pathway. On the other hand, SPLET mechanism represents the thermodynamically favored process in water. Results show that calculated enthalpies can be successfully correlated with Hammett constants (${\sigma}_m$) of the substituted Magnolols. Furthermore, calculated IP and PA values for substituted Magnolols show linear dependence on the energy of the highest occupied molecular orbital ($E_{HOMO}$).

DFT/B3LYP Study of the Substituent Effects on the Reaction Enthalpies of the Antioxidant Mechanisms of Magnolol Derivatives in the Gas-Phase and Water

Meysam Najafi,Mohammad Najafi,Houshang Najafi 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

In this paper, the study of various ortho- and meta-substituted Magnolol derivatives is presented. The reaction enthalpies related to three antioxidant action mechanisms HAT, SET-PT and SPLET for substituted Magnolols have been calculated using DFT/B3LYP method in gas-phase and water. Calculated results show that electronwithdrawing substituents increase the bond dissociation enthalpy (BDE), ionization potential (IP) and oxidation/ reduction enthalpy (O/RE), while electron-donating ones cause a rise in the proton dissociation enthalpy (PDE) and proton affinity (PA). In ortho- position, substituents show larger effect on reaction enthalpies than in metaposition. In comparison to gas-phase, water attenuates the substituent effect on all reaction enthalpies. In gasphase, BDEs are lower than PAs and IPs, i.e. HAT represents the thermodynamically preferred pathway. On the other hand, SPLET mechanism represents the thermodynamically favored process in water. Results show that calculated enthalpies can be successfully correlated with Hammett constants (σm) of the substituted Magnolols. Furthermore, calculated IP and PA values for substituted Magnolols show linear dependence on the energy of the highest occupied molecular orbital (EHOMO).

DFT/B3LYP Study to Investigate the Possible Ways for the Synthesize of Antioxidants with High Efficiency Based on Vitamin E

Meysam Najafi,Mohammad Najafi,Houshang Najafi 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

The possible ways for increasing the antioxidant properties of vitamin E have been investigated with density function theory. The effect of replacing three methyl groups of vitamin E with various substituents such as electron donating and electron withdrawing groups on the antioxidant properties of vitamin E were investigated. Also the effects of the reducing the number of atoms in the heterocyclic ring and replacing the oxygen heteroatom with other heteroatoms on the antioxidant properties of vitamin E were investigated. The novel structures that obtained from replacing methyl groups with substituents such as NH2, OH, COOH and NHMe have greater antioxidant activity than vitamin E. Obtained results reveal that novel structure that obtained with replacing O with NH hetroatom would be a better antioxidant than vitamin E. The results reveal that reducing the number of atoms in the heterocyclic ring is a better way to synthesize novel antioxidants.

Simulating three dimensional wave run-up over breakwaters covered by antifer units

Najafi-Jilani, A.,Niri, M. Zakiri,Naderi, Nader The Society of Naval Architects of Korea 2014 International Journal of Naval Architecture and Oc Vol.6 No.2

The paper presents the numerical analysis of wave run-up over rubble-mound breakwaters covered by antifer units using a technique integrating Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD) software. Direct application of Navier-Stokes equations within armour blocks, is used to provide a more reliable approach to simulate wave run-up over breakwaters. A well-tested Reynolds-averaged Navier-Stokes (RANS) Volume of Fluid (VOF) code (Flow-3D) was adopted for CFD computations. The computed results were compared with experimental data to check the validity of the model. Numerical results showed that the direct three dimensional (3D) simulation method can deliver accurate results for wave run-up over rubble mound breakwaters. The results showed that the placement pattern of antifer units had a great impact on values of wave run-up so that by changing the placement pattern from regular to double pyramid can reduce the wave run-up by approximately 30%. Analysis was done to investigate the influences of surface roughness, energy dissipation in the pores of the armour layer and reduced wave run-up due to inflow into the armour and stone layer.

Development of integrated marine monitoring network on southern coastline of Caspian sea

Najafi-Jilani, A.,Nik-Khah, A. The Society of Naval Architects of Korea 2011 International Journal of Naval Architecture and Oc Vol.3 No.2

Monitoring of water surfaces through permanent measurement of hydrodynamic and meteorological data is one of the main requirements in safe and sustainable water management. The Caspian Sea, the major surface water body in Iran, significantly affects more than 600 km of urban and industrial coastline. In the present work, an integrated marine monitoring network for the entire southern coastline of the Caspian Sea was developed. The main design concerns centered on the network measuring components and data recording, checking, filtering, gap recognition, and transferring systems. Four coastal monitoring stations were assigned, along with two regional collecting stations and one central data station for gathering, checking and delivering recorded data at different access levels. Applicable guidelines on selection of measuring devices for both shallow and deep water zones are presented herein.

Measuring and Decomposing Socioeconomic Inequalities in Adult Obesity in Western Iran

Najafi, Farid,Pasdar, Yahya,Hamzeh, Behrooz,Rezaei, Satar,Nazar, Mehdi Moradi,Soofi, Moslem The Korean Society for Preventive Medicine 2018 예방의학회지 Vol.51 No.6

Objectives: Obesity is a considerable and growing public health concern worldwide. The present study aimed to quantify socioeconomic inequalities in adult obesity in western Iran. Methods: A total of 10 086 participants, aged 35-65 years, from the Ravansar Non-communicable Disease Cohort Study (2014-2016) were included in the study to examine socioeconomic inequalities in obesity. We defined obesity as a body mass index ${\geq}30kg/m^2$. The concentration index and concentration curve were used to illustrate and measure wealth-related inequality in obesity. Additionally, we decomposed the concentration index to identify factors that explained wealth-related inequality in obesity. Results: Overall, the prevalence of obesity in the total sample was 26.7%. The concentration index of obesity was 0.04; indicating that obesity was more concentrated among the rich (p<0.001). Decomposition analysis indicated that wealth, place of residence, and marital status were the main contributors to the observed inequality in obesity. Conclusions: Socioeconomic-related inequalities in obesity among adults warrant more attention. Policies should be designed to reduce both the prevalence of obesity and inequalities in obesity by focusing on those with higher socioeconomic status, urban residents, and married individuals.

Different strengthening designs and material properties on bending behavior of externally reinforced concrete slab

Najafi, Saeed,Borzoo, Shahin Techno-Press 2022 Structural monitoring and maintenance Vol.9 No.3

This study investigates the bending behavior of a composite concrete slab roof with different methods of externally strengthing using steel plates and carbon fiber reinforced polymer (CFRP) strips. First, the concrete slab model which was reinforced with CFRP strips on the bottom surface of it is validated using experimental data, and then, using numerical modeling, 7 different models of square-shaped composite slab roofs are developed in ABAQUS software using the finite element modeling. Developed models include steel rebar reinforced concrete slab with variable thickness of CFRP and steel plates. Considering the control sample which has no external reinforcement, a set of 8 different reinforcement states has been investigated. Each of these 8 states is examined with 6 different uncertainties in terms of the properties of the materials in the construction of concrete slabs, which make 48 numerical models. In all models loading process is continued until complete failure occurs. The results from numerical investigations showed using the steel plates as an executive method for strengthening, the bending capacity of reinforced concrete slabs is increased in the ultimate bearing capacity of the slab by about 1.69 to 2.48 times. Also using CFRP strips, the increases in ultimate bearing capacity of the slab were about 1.61 to 2.36 times in different models with different material uncertainties.

Salt Tolerance in Transgenic Pea (Pisum sativum L.) Plants by P5CS Gene Transfer

Najafi F.,Rastgar-jazii F.,Khavari-Nejad R. A.,Sticklen M. The Korean Society of Plant Biotechnology 2005 Plant molecular biology and biotechnology research Vol.7 No.4

Slices of embryonic axis of mature pea (Pisum sativum L. cv. Green Arrow) seeds were used as explant. Transformation of explants was done via Agrobacterium tumefaciens bearing vector pBI-P5CS construct. The best results for inoculation of explants were obtained when they were immersed for 90 s at a concentration of $6{\times}10^8$ cell $ml^(-1)$ of bacterial suspension. Transformed pea plants were selected on $50\;mg\;l^(-1)$ kanamycin and successful transformants were confirmed by PCR and blotting. Transgenic plants were further analyzed with RT-PCR to confirm the expression of P5CS. Transgenic plants and non-transgenic plants were treated with different concentrations of NaCl 0 (control), 100, 150 and 200 mM in culture medium. Measurement of proline content indicated that transgenic plants produced more amino acid proline in response to salt in comparison with non-transgenic plants. Photosynthetic efficiency in transgenic plants under salt-stress was more than that of non-transgenic plants.

Statistical investigation of avalanches of three-dimensional small-world networks and their boundary and bulk cross-sections

Najafi, M. N.,Dashti-Naserabadi, H. American Physical Society 2018 Physical Review E Vol.97 No.3