Influence of the Structure on the Antioxidant Activity of Tetradentate Schiff Bases and their Copper(II) Complexes: Possible Mechanisms

The influence of the structure on the antioxidant activity of a series of Schiff bases and their copper(II) complexes as well as possible mechanisms of antioxidant activity were investigated. Schiff bases are derived from the condensation of ethane-1,2-diamine or propane-1,2-diamine and pentane-2,4-dione and/or 1-phenylbutane-1,3-dione. The corresponding complexes were synthesized. The antioxidant activity in vitro, determined using reversed-phase thin layer chromatography assay (RP TLC) based on the reaction with 2,2'-diphenyl-1-picrylhydrazyl, was expressed as Trolox equivalent antioxidant capacity (TEAC). The influence of the structure was observed on the basis of interpretable and informative descriptors calculated by hybrid density functional theory (DFT) methods. Structural features responsible for the antioxidant activity of the investigated compounds were discussed. Copper(II) complexes showed a significantly higher antioxidant activity than their corresponding ligands. Calculated quantum-chemical descriptors gave an insight to the reaction mechanism of the scavenging/antioxidant activity of tetradentate Schiff bases and their copper(II) complexes and two different reaction mechanisms were proposed

The state of biomass energy in Serbia

The paper presents a review of the energy potential of different types of biomass residues in agriculture and forestry, and actual state of biomass energy utilization in Serbia. The estimated values of annual energy potential are: about 1.7·10 6 toe (ton of oil equivalent) in biomass residues in agriculture, comprising crop farming, fruit growing, viniculture and stock breeding, and about 1 million toe of biomass from forestry, including different biomass residues and fuel wood. The total annual biomass energy potential of about 2.7·10 6 toe represents 40% of the total coal energy production in Serbia. Towns located in agricultural regions and in regions rich in forest can satisfy their energy demand for centralized heading systems with biomass residues from the territory of their own municipality. With appropriate energy policy, information campaign, research activities and general regulation in the field of biomass energy utilization, the share of biomass energy consumption in total energy balance can be significantly increased

RENEWABLE ENERGY SOURCES AND AGRICULTURE

Renewable sources of energy consider: energy made from biomass, solar energy, hydro and geothermal energy, as well as wind energy. The paper indicates energy consumption from renewable sources with focus on biomass, where substitution is the biggest possible. Avoiding atmosphere contamination with greenhouse gases is biomass advantage in comparison to fossil fuels

Development of Integrated Linear Programming Fuzzy-Rough MCDM Model for Production Optimization

One of the most common tools for achieving optimization and adequate production process management is linear programming (LP) in various forms. However, there are specific cases of the application of linear programming when production optimization implies several potential solutions instead of one. Exactly such a problem is solved in this paper, which integrates linear programming and a Multi-Criteria Decision-Making (MCDM) model. First, linear programming was applied to optimize production and several potential solutions lying on the line segment AB were obtained. A list of criteria was created and evaluated using the Improved Fuzzy Stepwise Weight Assessment Ratio Analysis (IMF SWARA). To obtain the final solution, a novel Rough compromise ranking of alternatives from distance to ideal solution (R-CRADIS) method was developed and verified through comparative analysis. The results show that the integration of linear programming and a Fuzzy-Rough MCDM model can be an exceptional solution for solving specific optimization problems

Development of Integrated Linear Programming Fuzzy-Rough MCDM Model for Production Optimization

One of the most common tools for achieving optimization and adequate production process management is linear programming (LP) in various forms. However, there are specific cases of the application of linear programming when production optimization implies several potential solutions instead of one. Exactly such a problem is solved in this paper, which integrates linear programming and a Multi-Criteria Decision-Making (MCDM) model. First, linear programming was applied to optimize production and several potential solutions lying on the line segment AB were obtained. A list of criteria was created and evaluated using the Improved Fuzzy Stepwise Weight Assessment Ratio Analysis (IMF SWARA). To obtain the final solution, a novel Rough compromise ranking of alternatives from distance to ideal solution (R-CRADIS) method was developed and verified through comparative analysis. The results show that the integration of linear programming and a Fuzzy-Rough MCDM model can be an exceptional solution for solving specific optimization problems

Percutaneous implantation of self-expandable aortic valve in high risk patients with severe aortic stenosis: The first experiences in Serbia

Background/Aim. Aortic stenosis (AS) is the most common valvular heart disease in elderly people, with rather poor prognosis in symptomatic patients. Surgical valve replacement is the therapy of choice, but a significant number of patients cannot undergo surgical procedure. We presented initial experience of transcatheter aortic valve implantation (TAVI) performed in Catheterization Laboratory of the Clinic for Cardiology, Clinical Center of Serbia. Methods. The procedures were performed in 5 patients (mean age 76 ± 6 years, 2 males, 3 female) with severe and symptomatic AS with contraindication to surgery or high surgical risk. The decision to perform TAVI was made by the heart team. Pre-procedure screening included detailed clinical and echocardiographic evaluation, coronary angiography and computed tomography scan. In all the patients we implanted a self-expandable aortic valve (Core Valve, Medtronic, USA). Six months follow-up was available for all the patients. Results. All interventions were successfully performed without significant periprocedural complications. Immediate hemodynamic improvement was obtained in all the patients (peak gradient 94.2 ± 27.6 to 17.6 ± 5.2 mmHg, p < 0.001, mean pressure gradient 52.8 ± 14.5 to 8.0 ± 2.1 mmHg, p < 0.001). None of the patients developed heart block, stroke, vascular complication or significant aortic regurgitation. After 6 months, the survival was 100% with New York Heart Association (NYHA) functional improvement in all the patients. Conclusion. This successful initial experience provides a solid basis to treat larger number of patients with symptomatic AS and high surgical risk who are left untreated. [Projekat Ministarstva nauke Republike Srbije, br. ON 175 020