Development of Square Wave Voltammetric Method for the Electrochemical Determination of Pregabalin as Pregabalin-Cu(II) Complex Using Graphite Electrode

In the present study, a square wave voltammetric (SWV) method was developed for the determination of pregabalin (PREG) in commercial drugs and biological samples as PREG-Cu(II) complex using graphite working electrode. A well-defined voltammetric signal of the complex was observed at nearly – 200 mV, by using Britton Robinson supporting electrolyte (B-R) at pH 7.5. There were some analytical conditions that have been evaluated through this research such as accumulation time and potential, scan rate, amplitude, frequency, and stirring rate to obtain a good voltammetric peak and high current without any overlap. In addition, some metal ions as potential interferences; such as Zn(II), Ni(II) and Cd(II) have been added at different concentrations to evaluate their effects on the voltammetric signal for PREG-Cu(II) complex. The SWV performance was investigated by monitoring parameters such as calibration curve, detection limit, reproducibility, stability and recovery. The calibration curve was studied over the range 5.0 ´10-8–1.0 ´10-6 mol L-1of (PREG) and 5.0 ´ 10-5 mol L-1 of copper ion (n=8, r2 = 0.99), yielded a linear relationship between voltammograms and complex concentrations. The sensitivity of SWV method was evaluated by calculating the detection limit which was found to be 6.5´10-9 mol L-1. The reproducibility, stability and recovery were studied for 5.0 х10-7 mol L-1of (PREG) and 5.0 х 10-5 mol L-1 of copper ion, yielded a relative standard deviation (RSD%) that was calculated to be 0.4% and good stability for the voltammetric signal, while the recovery was recorded to be 93±1.23%. The analytical voltammetric technique (SWV) was applied to determine PREG-Cu(II) complex in pharmaceutical capsules and biological fluids, specifically urine and plasma, where it gave recoveries of 90±1.0%, 89±1.23% and 86±1.23%, respectively

Electrochemical determination of Cd2+ in some Al-Madinah water samples and human plasma by cathodic stripping voltammetry in the presence of oxine as a chelating agent

AbstractA fast, simple, sensitive cathodic adsorptive stripping voltammetric procedure for quantitative analysis of Cd–oxine complex in al-Madinah city water samples and human plasma is described. The technique involves adsorptive accumulation of the complex on the working electrode, followed by square wave voltammetric determination of the preconcentrated analyte. In basic media, a cathodic electrochemical process involving the elimination of two protons occurs, and a mechanism for the reduction process is suggested. The optimal experimental parameters for assay of this complex are: carbonate supporting electrolyte pH 8, accumulation time 30s, accumulation potential −0.1V, scan rate 200mVs−1, pulse amplitude 80mV, frequency 40Hz, surface area of working electrode 0.6mm2 and convection rate 1000rpm. The calibration graph for determination of Cd–oxine was linear over the concentration range 5×10−8 to 4×10−7moll−1 (r=0.998), with a detection limit of 3.5×10−9moll−1. The precision of the proposed procedure was estimated by 10 successive voltammetric measurements of 2×10−6moll−1 Cd with 4×10−6moll−1 oxine, and the calculated relative standard deviation was 0.39%. The percentage recovery, indicating the accuracy of the analytical method, was 94±1.0%. Possible interference by several substances, including metals and ligands, was also evaluated. The electroanalytical method was successfully applied to assaying cadmium in water samples and biological fluids such as plasma

Electrochemical determination of rosiglitazone by square-wave adsorptive stripping voltammetry method

AbstractSquare-wave adsorptive stripping voltammetry technique was used to determine rosiglitazone (ROS) on the hanging mercury dropping electrode (HMDE) surface, in Britton Robinson buffer, pH=5. The voltammetric cathodic peak was observed at −1520mV vs. Ag/AgCl reference electrode. The voltammetric peak response was characterized with respect to pH, supporting electrolyte, accumulation potential, preconcentration time, scan rate, frequency, pulse amplitude, surface area of the working electrode and the convection rate. Under optimal conditions, the voltammetric current is proportional to the concentration of ROS over the concentration range of 5×10−8–8×10−7moll−1 (r=0.9899) with a detection limit of 3.2×10−11moll−1 using 120s accumulation time. The developed SW-AdSV procedure showed a good reproducibility, the relative standard deviation RSD% (n=10) at a concentration level of 5×10−7moll−1 was 0.33%, whereas the accuracy was 101%±1.0. The proposed method was successfully applied to assay the drug in the human urine and plasma samples with mean recoveries of 90±0.71% and 86±1.0%, respectively

General characteristics and common practices for ICT projects: Evaluation perspective

In today's business world, organizations are more dependent on Information and Communication Technologies (ICT) resources. Cloud services, communication services and software services are most common resources, enterprises are spending large amount. To install new services and upgrade existing services, ICT project are essential part of organization's business strategies. Researchers highlighted the real problem for the organization is to initiate new ICT projects and its evaluation after implementation. This research investigated the common approaches organizations using to start with ICT projects and how to evaluate its impact on after implementation. For this, we have extracted the number of steps with the help of literature review. To validate those steps, six case studies are selected for collecting the samples. The findings of this study elaborate that every ICT project has list of objectives i.e. strategic, informational, IT infrastructure and others. Furthermore, the results highlight that organizations believe on both financial and non-financial evaluation methods based on the type of organization i.e. public or private. Moreover, measurement process applied on project wise, monthly and yearly bases. Importantly, we have found that currently outsourcing plays significant role in success of ICT projects. The results of this study can be helpful for the organization to understand the type of ICT investments, approaches and possible impact on the organizations goals

Studies on wings symmetry and honey bee races discrimination by using standard and geometric morphometrics

Abstract: Morphometric is an essential tool for honey bee races discrimination and characterization. Such vital tool has been applied widely in honey bee researches. Unfortunately there is no available literature for confirming honey bee wings symmetry. Therefore, standard and geometric morphometric analyses were employed for investigating wings symmetry as well as for discriminating between Carniolan and Yemeni honey bees. Moreover, three angles of hind wings (H1, H2 and H3) were evaluated in the discrimination between the two races. Results of morphometric analyses strongly confirmed the symmetry of honey bee wings. Standard and geometric morphometric analyses successfully discriminate between the two races. Hind wing length and angle H3 could be incorporated in honey bee races discrimination

Insomnia in chronic renal patients on dialysis in Saudi Arabia

<p>Abstract</p> <p>Background</p> <p>Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis.</p> <p>Methods</p> <p>This was an observational cross-sectional study carried out over a period of five months in two hemodialysis centers in Saudi Arabia. To assess the prevalence of insomnia, we used the ICSD-2 definition. We also examined the association between insomnia and other sleep disorders, the underlying causes of renal failure, dialysis duration, dialysis shift, and other demographic data.</p> <p>Results</p> <p>Out of 227 enrolled patients, insomnia was reported by 60.8%. The mean patient age was 55.7 ± 17.2 years; 53.7% were male and 46.3% were female. Insomnia was significantly associated with female gender, afternoon hemodialysis, Restless Legs Syndrome, high risk for obstructive Sleep Apnea Syndrome and excessive daytime sleepiness (<it><b>P-values: </b></it>0.05, 0.01, < 0.0001, < 0.0001, and < 0.0001, respectively). No significant association was found between insomnia and other variables, including BMI, smoking habits, underlying etiology of renal failure, dialysis duration, association with hemoglobin, ferritin, and phosphorus or dialysis adequacy as measured by the Kt/V index.</p> <p>Conclusion</p> <p>Insomnia is common in dialysis patients and was significantly associated with other sleep disorders. Greater attention needs to be given to the care of dialysis patients with regard to the diagnosis and management of insomnia and associated sleep disorders.</p

Characteristics of the fission fragments induced by the 129Xe + natSn reactions at E = 8–15A MeV

The study of nuclear multifragmentation is important for understanding the reaction mechanisms in heavy-ion collisions. In the present work, we study the nuclear reaction 129Xe + natSn in the energy range E = 8 to 15 AMeV. This experiment was performed at GANIL with the multidetector INDRA. We study the charge distributions produced in this reaction, which are broad and cover a large atomic number range. By using the data of this experiment, we identify four channels differing by the number of fragments: 1, 2, 3 and 4 fragments. In this contribution we will show a method to reconstruct the average size and excitation energy of the primary fission fragments, before their decay. The method employed is based on the fragment-light charged particles relative velocity correlation functions. Preliminary results will be presented

Controlling of crystal size and optical band gap of CdO nanopowder semiconductors by low and high Fe contents

The CdO:Fe nanopowder semiconductors were synthesized by the sol–gel calcination for the first time. The structural properties of Fe doped CdO samples were analyzed by AFM and XRD measurements. XRD patterns of the pure and Fe-doped CdO samples reveal that the pure and Fe doped CdO nanopowders are polycrystalline of cubic CdO structure. The crystallite size of undoped and Fe-doped CdO samples is changed unsystematically with a regular increase of Fe content. The optical band gaps of Fe doped CdO samples were determined for the first time by diffused reflectance measurements. The optical band gap of the samples is increased with the increase of Fe dopant inside the host matrix (CdO) up to 15 % followed by a decrease in its value. It is evaluated that Fe doped CdO nanopowder semiconductors can be producted by sol–gel calcination for advanced technological application

Adsorption Sites of Hydrogen Atom on Pure and Mg-Doped Multi-Walled Carbon Nanotubes

Hydrogen adsorption sites on pure multiwalled carbon nanotube (MWCNT) and Mg-doped MWCNTs material system have been investigated using molecular dynamics (MD) simulations as well as quantum chemical calculations. Through combining MWCNTs with Mg, the hydrogen adsorption sites energy on this Mg-MWCNTs system is found to be larger than that of the pure MWCNTs. Additionally, it was found that, through Mg-doping, new adsorption sites for hydrogen molecules are created in comparison with undoped nanotubes. It is also found that H atom is preferably adsorbed at every place near magnesium atom

A novel barium oxide-based Iraqi sand glass to attenuate the low gamma-ray energies: Fabrication, mechanical, and radiation protection capacity evaluation

In the present work, untreated Iraqi sand with grain sizes varied between 100 and 200 μm was used to produce a colored glass sample that has shielding features against the low gamma-ray energy. Therefore, a weight of 70–60 wt % sand was mixed with 9–14 wt% B2O3, 8–10 wt% Na2O, 4–6 wt% of CaO, 3–6 wt% Al2O3, in addition to 0.3% of Co2O3. After melting and annealing the glass sample, the X-ray diffraction spectrometry was applied to affirm the amorphous phase of the fabricated glass samples. Moreover, the X-ray dispersive energy spectrometry was used to measure the chemical composition, and the MH-300A densimeter was applied to measure the fabricated sample's density. The Makishima-Makinzie model was applied to predict the mechanical properties of the fabricated glass. Besides, the Monte Carlo simulation was used to estimate the fabricated glass sample's radiation shielding capacity in the low-energy region between 22.1 and 160.6 keV. Therefore, the simulated linear attenuation coefficient changed between 10.725 and 0.484 cm−1, raising the gamma-ray energy between 22.1 and 160.6 keV. Also, other shielding parameters such as a half-value layer, pure lead equivalent thickness, and buildup factors were calculated. © 2022 Korean Nuclear SocietyPrincess Nourah Bint Abdulrahman University, PNU: PNURSP2022R28The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R28), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia