Chemical Methodologies

Abstract Tetrahydro[a]xanthenes-11-one derivatives have been widely used industrially as agrochemicals, cosmetics and pigments are reported to exert broad spectrum biological and pharmacological activities. Herein, we reported an efficient and environmentally benign one-pot multi–component reaction for the synthesis of tetrahydro[a]xanthenes-11-one derivatives from the reaction of dimedone, aromatic aldehydes, and 2-naphthols in the presence of a catalytic amount of nano-nano-CeO₂/Al₂O_3. The advantages of the effective method included good yields (91-98%), short reaction times, simple work-up and reusable catalyst. The catalyst could be recycled and reused for five times without much loss in its activity.
DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.1.7

Abstract In this study, two efficient applications for a novel modified polymer (polyethylene terephthalate [PET] modified with AgCl nanoparticles) were proposed and experimentally evaluated. First, PET-AgCl NPs were applied as an adsorbent to remove methylene blue (MB) dye, and the effect of pH, incubation time, concentration of MB, and temperature on the dye removal were studied and optimized to improve dye removal efficiency. The optimum condition included pH 9, temperature 45 ⁰C, and incubation time 24 h. The adsorption fitted the Temkin isotherm model. In the other part of the study, a composite of PET-AgCl NPs with multiwall carbon nanotubes (MWCNTs) was used to modify the gold electrode in order to detect MB dye.  The modified electrode exhibited a linear detection range, 5 μM to 10 nM, with a detection limit of 4.6 nM.
DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.2.8

Abstract In this study, a doxorubicin electrochemical sensor was fabricated by modification of paste electrode (PE) with reduced graphene oxide/Fe₃O₄ nanocomposite (rGO-Fe₃O₄-NC) and 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIZHFP). The rGO-Fe₃O₄-NC/HMIZHFP/PE was shown to have good catalytic effect for oxidation of doxorubicin in aqueous solution and oxidation current of anticancer drug was improved about 2.76 times. In addition, oxidation of doxorubicin was shown in a linear dynamic range 3.0 nM-280 µM with detection limit 1.0 nM at surface of rGO-Fe₃O₄-NC/HMIZHFP/PE. The recovery data 99.33-103.7 % was calculated for measurement of doxorubicin in injection and pharmaceutical serum using rGO-Fe₃O₄-NC/HMIZHFP/PE as sensor that is acceptable for a new analytical sensor. 
DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.3.9

Abstract Interactions between emotional and environmental factors shape the human`s behaviour and cause people to demonstrate different reactions to the same subjects. Some of the inner effective factors that influence the brain function are genetic, physiology, biology, biochemistry and etc. Hormones and neurotransmitters are biochemical that leak to the body liquids like blood, through the circulatory system spreading all over the body and finally affecting the function of the target organs function such as brain and consequently decision making and behavioural processes. Like all behaviours, financial decisions are directly associated with the biochemistry of the brain and hormones functions. Different hormones variously influence human’s behaviours and assessing the reason, intensity and direction of this association have drawn scholar’s attention of the various field of studies and have made a multidisciplinary subject that links finance, economy, neuroscience, neurology, ethology and other specialties. The current study reviewed some of the most significant and recent investigations in the period of 2015-2019 associated with the effect of dopamine and oxytocin on the human financial behaviours especially risk attitude and risk taking. DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.4.0

Abstract Lipid polymer hybrid nanoparticles [LPHNPs] are a system of nanoparticles which are a mixture of lipid monolayer shell and biodegradable polymer core developed for intelligent drug delivery of anti-cancer drugs. The present study aimed to develop and optimize LPHNPs for targeted delivery of etoposide anticancer drug through designing an experiment with Response Surface Methodology [RSM] and Central Composite Design [CCD] with quantitative control of three independent variables of lipid, polymer and polyvinyl alcohol [PVA] percentage which examined their effect on nanoparticle size and encapsulation efficiency [EE]. LPHNPs were prepared by one-step nanoprecipitation method. The results showed the optimizing of the tested values ​​of polymer, lipid and %PVA. Lipid-polymer hybrid formulation was reported to be about 14% after 80 hr. The cytotoxicity effect of etoposide-containing LPHNPs for lung cancer cell lines A-549 and Calu6 showed higher antitumor activity compared with the free drug used. Further, the results showed that the high polymer concentration led to more space for drug enclosure and created a relatively compact matrix; therefore, the drug encapsulation efficiency increased as the amount of polymer increased. In LPHNPs, increasing the amount of polymer, lipid and increasing the percentage of PVA used in nanocarrier synthesis generally improved particle size and encapsulation efficiency. The results also showed that LPHNPs could be effective for the delivery of hydrophobic drugs such as etoposide. DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.5.1

Abstract One of the most common causes of death in today's society is cancer. The treatments used in the treatment of cancers have their own side effects that have created many problems in the complete treatment of cancer. In classical and conventional drug delivery systems, the drug is distributed aimlessly and generally throughout the body, and the cells take part in the drug from the blood based on their position relative to the drug. As a result, a significant amount of the drug is wasted and eliminated without being used by the body. The most important disadvantages of the old methods of drug delivery are drug wastage, high cost of raw materials, the occurrence of side effects related to the dose, physical and chemical incompatibilities, as well as clinical drug interactions. Nano-liposomes are nanometer-scale liposomes that are one of the most useful drug delivery systems in the field of drug release and retention, which both provides a higher level than liposomes and increases solubility and access to bioavailability as well as improved drug release. Important reasons for the use of nano-liposomes in the pharmaceutical industry are their similarity to cell membranes and trapping of hydrophobic and hydrophilic substances, drug delivery to the target tissue, control of drug flow in the bloodstream and good biocompatibility. Another important feature of nano-liposomes is the coating of water-soluble drugs in the central aqueous portion and fat-soluble drugs within its bilayer membrane. Nano liposomes can be effective in reducing drug toxicity and increasing drug efficacy.
 
DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.6.2

Abstract In the current study, we attempted to introduce a novel approach to stop the fire spread in all type of fires and improve the fire and explosion safety for LNG storage. In so doing, we relied on the application of innovative technology “Sogda”. The design of a screen "Sogda" consists of two parallel metallic grids stretched over metallic frames. Active special water spray nozzles located between two parallel fixed grids creates water film on the surface of grid and water vapor droplet-air medium in the space between two parallel grids. This complex process partially attenuates the radiant heat flow from 45 to 100 kW/m² or more times, representing mainly in electromagnetic waves in an IR diapason, as a result of thermo-physical effects and it is optical phenomena that prevent the passage of explosive, toxic gases.
DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.7.3

Abstract Clean hydrocarbon is an alternative source of other fuels like coal and natural gas. Based on the literature, the significance of hydrocarbon production via Fischer-Tropsch synthesis (FTS) process cause to develop a new mathematical algorithm response surface methodology (RSM)/ design of experiment (DOE). The influence of important factors, like pressure, temperature and feed ratio (H2/CO) on the performance of the FTS are examined. The experiments are conducted in the range of: P = 1.9-3.75 bar, T = 523-563 K, and H2/CO ratio = 0.85-1.85 at set space velocity (2000 h-1). A second-order model is developed via RSM in terms of independent input variables to describe the CO conversion and selectivity of CO2 and C5+ as the responses. It is concluded that at low temperature and H2/CO ratio, CO2 selectivity increase significantly and C5+ selectivity decreases appreciably when pressure increases. Moreover, at low pressure an increase in temperature, reduces CO conversion. According to contour plots and analysis of variance (ANOVA), it is illustrated that the maximum CO conversion was obtained at P = 3.21 bar, T =563 K and H2/CO = 1.85 while for C5+ the maximum is observed at P = 3.67 bar, T = 529.1 K, and H2/CO = 0.91, and CO2 selectivity is minimized at P = 1.93 bar, T = 563 K and H2/CO = 1.85. The predicted conversion and selectivity are in good accordance with experimental results which is an indication of the accuracy of RSM methodology in designing and optimizing the FT process.

Abstract < p>This study focused on gamma alumina nanoparticles used for the adsorption of the cationic dye methyl red from aqueous solutions. Batch adsorption studies were carried out to investigate various parameters including pH, gamma alumina nanoparticles dosage, and temperature and contact time. The concentration of dye methyl red was measured using a UV-vis Spectrophotometer at the wavelength of 410 nm. The optimum adsorption conditions were found to be pH=3, adsorbent dose=0.04 g, temperature=298 K and contact time=50 min. The experimental results of this work were compared with Langmuir, Friendlich and Tamkin''s isotherm models. The results obtained from isotherm models showed that the surface adsorption of these dyes on the adsorbent followed the Langmuir isotherm model. The analysis of thermodynamic data showed that the adsorption process of the studied dyes on the adsorbent surface is spontaneous (The negativ value of ΔG⁰) and exothermic (The negativ value of ΔH⁰). DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.8.4

Abstract Using a solid-phase extraction for the determination of VPA, this study aimed to prepare a valproic acid (VPA) imprinted silica gel adsorbent by surface molecular imprinting technique. VPA-imprinted silica adsorbent was characterized by FTIR spectroscopy. The VPA adsorption from solutions was studied in SPE mode. All influenced parameters on adsorption efficiency, including the elution concentration, MIP amount, VPA concentration, pH and salting effect, sample flow rate, column performance repeatability (relative standard deviation) were optimized independently. The prepared adsorbent showed significant adsorption capacity and selectivity for VPA. In the condition of sodium hydroxide solution (0.1 M), MIP polymer (250 mg), VPA (10^-4M), sample flow rate (1 ml min^-1), pH around 2-6 in the presence of 4 % NaCl, total VPA retention showed better reproducibility than 5%. Recovery of VPA was about 94.6 to 98.1% and the relative standard deviation was less than 5.69%.  These results demonstrated that the prepared adsorbent can be used to measure VPA in biological samples. DOR: https://dorl.net/dor/20.1001.1.26457776.2021.5.2.10.6