Electrocatalytic Behavior of Levodopa at MultiWall Carbon Nanotubes and 4-((E)-(2-Methyl-4-Nitrophenylimino) Methyl) Benzene-1,2-Diol Modified Glassy Carbon Electrode

This work describes a glassy carbon electrode (GCE) modified by 4-((E)-(2-methyl-4-nitrophenylimino) methyl) benzene-1,2-diol (abbreviated as MBD) and multiwall carbon nanotubes (MWNT) as an electrochemical sensor for monitoring of levodopa (LD) concentration. Different electrochemical parameters of MBD were obtained at MWCNT-GCE by cyclic voltammetry. Also the electrocatalytic behavior of LD was investigated at the MBD-MWNT-GCE by cyclic voltammetry, chronoamperometry and differential pulse voltammetry. Using the electrocatalysis of LD V in phosphate buffer solution pH 7.0 on this modified electrode it is possible to obtain a linear calibration curve from 5.0 10 – 7 to 9.0 10 – 4 M and a detection limit of 0.37 μM for LD by differential pulse voltammetry. The electrode was successfully applied for determination of LD in real sample. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3493

Determination of silver(I) by flame atomic absorption spectrometry after separation/preconcentration using modified magnetite nanoparticles

AbstractA new, simple, fast and reliable method has been developed for the separation/preconcentration of trace amounts of silver ions using 2-mercaptobenzothiazole/sodium dodecyl sulfate immobilized on alumina-coated magnetite nanoparticles (MBT/SDS-ACMNPs) and their determination by flame atomic absorption spectrometry (FAAS). Optimal experimental conditions, including pH, sample volume, eluent concentration and volume, and co-existing ions, have been studied and established. Under optimal experimental conditions, the enrichment factor, detection limit, linear range and relative standard deviation (RSD) of Ag(I) ions were 250 (for 500 mL of sample solution), 0.56 ng mL−1, 2.0–100.0 ng mL−1 and 3.1% (for 5.0 μg mL−1, n=10), respectively. The presented procedure was successfully applied for determination of silver content in the different samples of water

[Bis(2-hydroxyl imino)1-phenyl, 2-(2-qunolile)1-ethanona]Aluminium(III) Complex as Carrier for a Salicylate-Sensitive Electrode

A salicylate-selective electrode based on the complex [bis(2-hydroxyl imino)1-phenyl,2-(2- qunolile)1-ethanona]Aluminium(III) as the membrane carrier was developed. The electrode exhibited a good Nernstian slope of –59.1 ± 0.4 mV / decade (mean value ± standard deviation, n = 5) and a linear range of 1.0 × 10–6– 1.0 × 10–1 mol L–1 for salicylate. The limit of detection was 5.0 × 10–7 mol L–1. The electrode had a fast response time of 15 s and could be used for more than three months. The selectivity coefficients were determined by the fixed interference method (FIM) and could be used in the pH range of 2.0–7.8. It was employed as an indicator electrode for direct the determination of salicylate in pharmaceutical samples

Multiwall Carbon Nanotubes Modified Carbon Paste Electrode for Determination of Copper(II) by Potentiometric and Impedimetric Methods

Abstract A chemically modified carbon paste electrode with multiwall carbon nanotube (MWCNT) was prepared and used as a sensor for Cu 2+ ion. The unique chemical and physical properties of CNT have paved the way to new and improved sensing devices. A central composite chemometrics design was applied for multivariate optimization of the effects of three significant parameters (Graphite powder (X 1 ), MWCNT (X 2 ) and Ionophre (X 3 )) influencing the response of the electrode. In the optimized conditions, the electrode exhibits a Nernstian slope of 30.1 mV/decade in a linear range between 1.0×10 -6 to1.0×10 -1 M over a wide pH range (2.0-6.5). Importantly, the effect of the MWCNT on the performance of electrode was investigated by impedance technique, that showed the MWCNT helps the transduction of the signal in carbon paste electrode and the charged transfer resistance (R ct ) was reduced. The impedimetric results indicated that the linear concentrations range was 1.0×10 −7 to 1.0×10 −1 M and in comparison with potentiometry, the pH range increased to 2.0−7.5. JNS All rights reserve

Nanostructured Modified Electrode for Electrocatalytic Determination of Epinephrine in the Presence of Acetaminophen

Abstract In this paper, a nanostructured modified electrode was fabricated by incorporating of 2,2′-[1,9-nonanediylbis(nitriloethylidyne)]-bishydroquinone (NNH) as a newly synthesized modifier and TiO 2 nanoparticles to the carbon paste (MTCPE) and then was used for the electroanalysis of epinephrine (EP). The electrochemical studies were carried out by using cyclic voltammetry, chronoamperometry and differential pulse voltammetry (DPV) techniques. It has been found that the oxidation of EP at the surface of this electrode occurs at a potential about 235 mV less positive than that of an unmodified carbon paste electrode. A dynamic range of 1.0-2000.0 µM, with a detection limit of 0.37 µM for EP, was obtained using DPV. Also, this modified electrode exhibits well separated oxidation peaks for EP and acetaminophen (AC) using DPV. JNS All rights reserve

The association between real-life markers of phone use and cognitive performance, health-related quality of life and sleep

INTRODUCTION: The real-life short-term implications of electromagnetic fields (RF-EMF) on cognitive performance and health-related quality of life have not been well studied. The SPUTNIC study (Study Panel on Upcoming Technologies to study Non-Ionizing radiation and Cognition) aimed to investigate possible correlations between mobile phone radiation and human health, including cognition, health-related quality of life and sleep. METHODS: Adult participants tracked various daily markers of RF-EMF exposures (cordless calls, mobile calls, and mobile screen time 4 h prior to each assessment) as well as three health outcomes over ten study days: 1) cognitive performance, 2) health-related quality of life (HRQoL), and 3) sleep duration and quality. Cognitive performance was measured through six "game-like" tests, assessing verbal and visuo-spatial performance repeatedly. HRQoL was assessed as fatigue, mood and stress on a Likert-scale (1-10). Sleep duration and efficiency was measured using activity trackers. We fitted mixed models with random intercepts per participant on cognitive, HRQoL and sleep scores. Possible time-varying confounders were assessed at daily intervals by questionnaire and used for model adjustment. RESULTS: A total of 121 participants ultimately took part in the SPUTNIC study, including 63 from Besancon and 58 from Basel. Self-reported wireless phone use and screen time were sporadically associated with visuo-spatial and verbal cognitive performance, compatible with chance findings. We found a small but robust significant increase in stress 0.03 (0.00-0.06; on a 1-10 Likert-scale) in relation to a 10-min increase in mobile phone screen time. Sleep duration and quality were not associated with either cordless or mobile phone calls, or with screen time. DISCUSSION: The study did not find associations between short-term RF-EMF markers and cognitive performance, HRQoL, or sleep duration and quality. The most consistent finding was increased stress in relation to more screen time, but no association with cordless or mobile phone call time

Gli effetti sul flusso aereo nasale della turbinoplastica inferiore in corso di rinosettoplastica

La rinoplastica è una procedura chirurgica molto comune e al tempo stesso di elevata complessità. Uno degli aspetti più discussi di tale chirurgia sono gli insoddisfacenti esiti funzionali dovuti spesso ad un eccessivo restringimento dell’area della valvola nasale. Alcune procedure, come la turbinoplastica inferiore, possono favorire la prevenzione di tali problematiche ostruttive. L’intento del presente studio è quello di indagare gli effetti della turbinoplastica inferiore sulla resistenza nasale e sull’ostruzione respiratoria. In 50 pazienti è stata effettuata un’analisi preoperatoria e sei mesi dopo rinoplastica con turbinoplastica inferiore mediante rinomanometria anteriore attiva. Nessuno dei pazienti ha lamentato sintomatologia ostruttiva nasale nel preoperatorio o nel corso del postoperatorio. In accordo con i dati rinomanometrici sia le resistenze inspiratorie che quelle espiratorie hanno presentato valori migliori nel postoperatorio, ma solo le resistenze espiratorie hanno presentato una significatività statistica (p = 0,034). Le differenze in termini di flusso nasale fra maschi, femmine e differenti gruppi di età non sono state significative (p > 0,05). In conclusione dai dati del nostro studio emerge che la rinosettoplastica, associate a turbinoplastica parziale non ha un impatto negativo sulla funzionalità nasale ed in particolare sul flusso aereo attraverso le cavità nasali

Modern approaches to production of safe and effective genetically modified rabies vaccines for animals

Rabies is a dangerous zoonoticdisease that affects the central nervous system, causes encephalomyelitis and paralyses and Is almost invariably fatal. The disease causes significant economic losses associated with the death of animals, outbreak consequences, strict restrictions on domestic and international trade in livestock products, preventive and quarantine measures, laboratory tests. The World Organization for Animal Health recommends vaccination to control rabies. Taking into account that there is a lack of affordable high-quality vaccines to globally prevent and control the disease, stable, attenuated production strains of rabies virus with broad cross-activity against various variants of the pathogen shall be considered as ideal candidates to produce high-quality, safe and effective vaccines. Currently, someapproachesareappliedtoreducethevirusvirulenceandimprovesafetyof rabies vaccines. Reverse genetics is very popular now. It provides new approaches to study functions of a specific gene by analyzing phenotypic effects after direct manipulations with nucleotide sequences. The methods of reverse genetics have revolutionized molecular biology and have become apowerful tool to study genetics of RNA viruses. These methods are widely used to study rabies virus. The use of reverse genetics has made it possible to modify rabies virus production strains for manufacture of modern genetically modified rabies vaccines that induce a persistent and long-term immunity. The review briefly covers general approaches to development of viral vectors with the purpose to create genetically modified rabies vaccines