Abdulfattah Mohammed Alkherraz; Mohammed Mustafa Sebsi; Mohamed Sassi; Khaled Muftah Elsherif
Abstract
The aim of this study was to estimate and compare some of chemical constituents in nuts and seeds consumed as snacks and available in the local market of Misurata city in Libya. 18 kinds of local and imported raw and roasted nuts and seeds samples were randomly collected from stores distributed across ...
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The aim of this study was to estimate and compare some of chemical constituents in nuts and seeds consumed as snacks and available in the local market of Misurata city in Libya. 18 kinds of local and imported raw and roasted nuts and seeds samples were randomly collected from stores distributed across the city, with 3 - 4 replicates of each kind, in order to estimate the concentrations of some chemical components and heavy elements, which were lead (Pb), cadmium (Cd), Iron (Fe), copper (Cu), chromium (Cr), manganese (Mn), cobalt (Co), zinc (Zn), nickel (Ni), moisture, ash, total solids and protein. The dry digestion method was used to prepare the samples for heavy metals determination using Flame Atomic Absorption Spectrometer. Also, moisture, ash and total solids contents were determined, and Kjeldahl method was used to estimate proteins. The results showed that the average concentrations of heavy metals varied significantly with sample kind. The levels of the studied metals were as follows: 0.075 - 1.167, 31.50 - 116.00, 0.325 - 1.325, 9.425- 71.00, 0.025-3.87, 8.325- 24.825, 0.175- 1.250, 0.050- 0.750, 43.00- 98.325 mg/kg, for Co, Zn, Ni, Mn, Pb, Cu, Cr, Cd, and Fe, respectively. Also, levels of moisture contents, ash contents, total solids contents, and protein levels were: 4.0 - 8.5%, 2.0 - 11.39%, 91.5 - 96.0%, and 11.8 - 33.2%, respectively. Most of the obtained results were consistent with the previous studies and within the permissible limits.
Homa Shafieekhani; Somayeh Karimi; Mohammad Torkashvand
Abstract
A new organic compound, namely dihydropyrimido [4,5-b][1,6] naphthyridine-2,4, 6, 8(1H,3H,7H,9H)-tetraones with amino acid moiety (DHPN) was synthesized and characterized by 1H, 13C Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy experiments. DHPN was investigated ...
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A new organic compound, namely dihydropyrimido [4,5-b][1,6] naphthyridine-2,4, 6, 8(1H,3H,7H,9H)-tetraones with amino acid moiety (DHPN) was synthesized and characterized by 1H, 13C Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy experiments. DHPN was investigated for the first time as a green inhibitor of mild steel (A105) corrosion in acidic (0.1, 0.5 mol L-1 H2SO4 and HCl) solutions using potentiodynamic polarization technique. The results showed that, inhibition efficiency increased with the inhibitor concentration within the range of 0.95-19 mg L-1. The polarization curves demonstrated that, this compound act as a mixed type inhibitor. The adsorption of the DHPN molecule on the surface of mild steel was found to obey the Langmuir adsorption isotherm. Besides, data processing methods like support vector machine modelling was performed to prove the relationship between inhibitory effect and molecular structure.
Pourya Abbasi; Keyvan Shayesteh; Vahid Vahidfard; Mehdi Hosseini
Abstract
Nickel is one of the metallic impurities that should be removed from the electrolyte solution before the electrowinning of zinc. This study investigated the parameters affecting the process of nickel removal in an Iranian zinc smelter plant by the response surface methodology. According to the results ...
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Nickel is one of the metallic impurities that should be removed from the electrolyte solution before the electrowinning of zinc. This study investigated the parameters affecting the process of nickel removal in an Iranian zinc smelter plant by the response surface methodology. According to the results of experiments, the optimum condition for removal of nickel was obtained at temperature of 85 °C, the residence time of 60 minutes, zinc powder of 2.5 g/l, mixing speed of 500 rpm, and pH of 5. With regards to the resulting model from the Design-Expert software, the significant parameters were concentration, residence time, and temperature, respectively.
Zahra Garkani Nejad; Abuozar Ghanbari
Abstract
Three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques are useful methods for ligand-based drug design by correlating physicochemical descriptors from a set of related compounds to their known molecular activity or molecular property values. A novel clubbed triazolyl thiophene ...
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Three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques are useful methods for ligand-based drug design by correlating physicochemical descriptors from a set of related compounds to their known molecular activity or molecular property values. A novel clubbed triazolyl thiophene series of cdk5/p25 inhibitors were selected to establish 3D-QSAR models using Comparative molecular field analysis (CoMFA) and Comparative molecular similarity indices analysis (CoMSIA) methods. The optimum CoMFA and CoMSIA models obtained, were statistically significant with cross-validated correlation coefficients r2cv (q2) of 0.539 and 0.558, and conventional correlation coefficients (r2) of 0.980 and 0.967, respectively. A training set containing 88 molecules and a test set containing 24 molecules served to establish the QSAR models. Independent test set validated the external predictive power of both models with predicted correlation coefficients (r2pred) 0.968 and 0.945 for CoMFA and CoMSIA, respectively. Molecular docking was applied to explore the binding mode between the ligand and the receptor. The information obtained from molecular modeling studies may be helpful to design novel CDK5/P25 inhibitors with desired activity.
Nourolhoda Razavi; Amene Zendegi-Shiraz; Zarrin Eshaghi
Abstract
This study considers identification and determination of phthalates esters in cosmetic samples. The dispersive solid phase extraction was used for extraction of analytes prior to high performance liquid chromatography analysis. The solid sorbent for extraction was polyethylene glycol grafted on cupric ...
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This study considers identification and determination of phthalates esters in cosmetic samples. The dispersive solid phase extraction was used for extraction of analytes prior to high performance liquid chromatography analysis. The solid sorbent for extraction was polyethylene glycol grafted on cupric oxide nanoparticles (PEG-g-CuO-NPs). This sorbent was first synthesized and characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray(EDX) and fourier-transform infrared spectroscopy (FT-IR) then efficiently applied for extraction of analytes. The extraction conditions like amount of sorbent, kind and volume of desorption solvent, extraction and desorption time, and pH of sample solution were optimized. The validation of method carried out under optimum conditions. Linear ranges were 0.005-4 µgmL-1 with the coefficient correlation (R2) in the range of 0.9914-0.9962. The limits of detection (LODs) (3S/N) were 0.0025 to 0.005 µgmL-1 and acceptable repeatability’s (RSDs below 6.45%, n=5) obtained. Application of proposed method was investigated by extraction of phthalates in shampoo and body wash for babies which satisfaction results achieved.
Nosrat Madadi Mahani
Abstract
The interactions of 6twk protein with Ectoine drug, Polyamidoamine (PAMAM) /Ectoine and histidine modified PAMAM/Ectoine were investigated using molecular docking and molecular dynamics simulation. Based on the results of molecular docking increasing of binding energy and the decreasing of inhibition ...
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The interactions of 6twk protein with Ectoine drug, Polyamidoamine (PAMAM) /Ectoine and histidine modified PAMAM/Ectoine were investigated using molecular docking and molecular dynamics simulation. Based on the results of molecular docking increasing of binding energy and the decreasing of inhibition constant of the compounds, increase their inhibitory activity. Protein stability in complex with these ligands was investigated using molecular dynamics simulation approach. Results molecular dynamics simulation displayed that histidine modified PAMAM/Ectoine with the lowest mean square displacement (MSD) is the better suitable to deliver the ectoine drug. This causes the most controlled/diffusion of ectoine drug molecule. So, histidine modified PAMAM/Ectoine conjugate can be introduced for further investigations on interaction of ectoine drug and 6twk protein.
Abdolhamid Hatefi-Mehrjerdi; ُُSoghra Rafiei Boldaji; Mohammad Reza Yaftian; Hassan Shayani-Jam
Abstract
A novel Buprenorphine (BPR) sensor is fabricated based on nanocomposite film of benzene-1,3-disulfonate anion doped overoxidized polypyrrole/multiwalled carbon modified glassy carbon electrode. The carbon nanotubes were drop-casted on bare electrode, and then thin layer of benzene-1,3-disulfonate-doped ...
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A novel Buprenorphine (BPR) sensor is fabricated based on nanocomposite film of benzene-1,3-disulfonate anion doped overoxidized polypyrrole/multiwalled carbon modified glassy carbon electrode. The carbon nanotubes were drop-casted on bare electrode, and then thin layer of benzene-1,3-disulfonate-doped overoxidized polypyrrole formed electrochemically on it. Effect of experimental conditions involving supporting electrolyte pH, carbon nanotubes suspension drop size, and the number of potential cycles in overoxidized polymerization were optimized by monitoring the voltammetry responses of the modified electrode. Then the optimized modified electrode was used for electrochemical sensing of BPR by differential pulse voltammetry, which exhibited a linear growth with high sensitivity in anodic peak currents at the BPR concentration range of 0.06-40 µM, and a detection limit of 28 nM. Finally, the determination of BPR in urine real samples was performed by the new sensor and satisfactory results obtained.
Alaa S. Amin; Hesham El-Feky
Abstract
A highly selective optical sensor for V(IV) ions was established depended on entrapment of a sensitive reagent, 5-(2`,4`-dimethylphenylazo)-6-hydroxy-pyrimidine-2,4-dione (DMPAHPD), in a silica sol–gel thin film coated on a glass substrate. The thin films fabricated depended on tetraethoxysilane ...
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A highly selective optical sensor for V(IV) ions was established depended on entrapment of a sensitive reagent, 5-(2`,4`-dimethylphenylazo)-6-hydroxy-pyrimidine-2,4-dione (DMPAHPD), in a silica sol–gel thin film coated on a glass substrate. The thin films fabricated depended on tetraethoxysilane (TEOS) as precursor, sol–gel of pH = 2.5, water: alkoxyde ratio of 4: 1 and DMPAHPD concentration of 2.5 × 10−4 M. The effect of sol–gel parameters on sensing behavior of the fabricated sensor was also illustrated. The fabricated sensor can be used to detect V(IV) ion with an outstanding high selectivity over a wider dynamic range of 5.0–145 ng mL−1 and a detection limit of 1.35 ng mL−1. It also recorded reproducible results with relative standard deviation of 1.75% and 1.02% for 20 and 70 ng mL−1 of V(IV), respectively, along with a fast response time of two min. Total vanadium was determined after reduction of V(V) to V(IV) using ascorbic acid as reducing agent. The V(V) amounts were estimated by subtracting the concentration of V(IV) from the total vanadium concentration. Interference studies reported a good selectivity for V(IV) with trapping DMPAHPD into sol–gel matrix and appropriately adjusting the structure of doped sol–gel. The proposed sensor was compared with others and was applied to define vanadium in different environmental samples with good results.
Javad Feizy; Sima Ahmadi; Moslem Jahani; R. Lakshmipathy
Abstract
The present investigation reports a quantitative analysis of metals in the saffron samples collected from seven different saffron production areas in the Khorasan Razavi province, Iran. Khorasan Razavi is the leading producer of saffron in Iran, and more than 95% of the global production of this expensive ...
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The present investigation reports a quantitative analysis of metals in the saffron samples collected from seven different saffron production areas in the Khorasan Razavi province, Iran. Khorasan Razavi is the leading producer of saffron in Iran, and more than 95% of the global production of this expensive spice is attributed to Iran. Since environmental pollution is increasing, saffron is contaminated with various organic and inorganic contaminants such as heavy metals. Twenty-one saffron samples were collected in the flowering season of 2018 and analyzed for metal content. The concentration of microelements and heavy metals including Zn, Fe, Ca, Mn, Mg, Na, K, Pb, Cd, Cu, and Cr was determined in the samples collected from three farms in each production area with graphite furnace and flame atomic absorption spectroscopy. The results revealed that the collected saffron stigmas contain a wide range of minerals and heavy metals with different concentrations. Potassium is the most abundant element, and Cd had the least concentration in the saffron. It can be concluded that ecological management plans such as reducing chemical fertilizers and improving organic fertilizers can decline the extent of heavy metals in the saffron.
Amirkhosro Beheshti; Tahereh Rohani; Sayed Zia Mohammadi; Maryam Dadkhodazadeh
Abstract
Molybdenum disulfide as a transition metal dichalcogenide was prepared by a hydrothermal method and hybridized with graphene oxide (MoS2/GO). The as-prepared materials were investigated by Fourier transform infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray elemental analysis ...
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Molybdenum disulfide as a transition metal dichalcogenide was prepared by a hydrothermal method and hybridized with graphene oxide (MoS2/GO). The as-prepared materials were investigated by Fourier transform infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray elemental analysis (EDX) techniques as well transmission electron microscopy (TEM) image. The nanomaterial with its electrocatalytic properties was applied as an electro-nanocatalyst for loading on a glassy carbon electrode (MoS2/GO-GCE) for detection of carbamazepine as an anti-epileptic in real body samples. The simple and low-cost developed electrochemical sensor detected carbamazepine with a vast linear concentration range(30-350nM), very low detection limit about 6.0nM and significant sensitivity equal to 0.134µA/nM.
Tesfu Hailu; Yaw-Kuen Li; Merid Tessema
Abstract
An analytical method that offers fast response with a cheap instrument and simple sample preparation is an ideal technique that is required in scientific analysis. Electrochemical sensing is an analytical method that suits the above criteria to determine various samples using different electrode material. ...
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An analytical method that offers fast response with a cheap instrument and simple sample preparation is an ideal technique that is required in scientific analysis. Electrochemical sensing is an analytical method that suits the above criteria to determine various samples using different electrode material. Detection of chloramphenicol in agricultural products and drug samples using cheap electrode materials is highly required due to its wide application in agriculture. In this study a cost-effective activated SPCE was made electrochemically to determine chloramphenicol in eye-drop and pasteurized milk. The activation of the SPCE was straightforward and done by cycling 0.5 M KOH using LSV techniques. Surface imaging, spectroscopy, and electrochemical analyses showed that there is an effective formation of new functional groups during the activation. The activated SPCE gave a higher peak current for Chloramphenicol during the CV and SWV study using PBS pH 6.5 compared to that of the bare one. Utilizing the optimal SWV conditions, a linear calibration curve was obtained in the range of 0.05‒100 µM with quite a small detection limit of 20 nM. In addition to the high sensitivity, stability, and remarkable recovery, the excellent reproducibility makes the activated SPCE applicable in real sample analysis.
Hamid-Reza Zare-Mehrjardi
Abstract
Acridine orange supported on multi-walled carbon nanotube (MWCNT) is used for modification of carbon-paste electrode. The studies show that acridine orange efficaciously immobilized in the matrix of the electrode by applying nafion/MWCNT composite under the ultrasonic condition. The results of voltammetric ...
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Acridine orange supported on multi-walled carbon nanotube (MWCNT) is used for modification of carbon-paste electrode. The studies show that acridine orange efficaciously immobilized in the matrix of the electrode by applying nafion/MWCNT composite under the ultrasonic condition. The results of voltammetric experiments demonstrate that the prepared electrode has an effective response to DA and AA and a relatively big anodic peak separation (nearly 368 mV) is obtained for these compounds. Good sensitivity and selectivity and very low detection limit (0.03 µM) makes the modified electrode very effective in the manufacture of simple devices for the concurrent detection of dopamine in the presence of ascorbic acid in clinical and pharmaceutical preparations.
