doping agent
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Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3071
Author(s):  
Ermelinda Falletta ◽  
Anna Bruni ◽  
Marta Sartirana ◽  
Daria C. Boffito ◽  
Giuseppina Cerrato ◽  
...  

In the present study, the development of innovative polyurethane-polyaniline/TiO2 modified floating materials applied in the sorption and photodegradation of rhodamine B from water matrix under solar light irradiation is reported. All the materials were fabricated with inexpensive and easy approaches and were properly characterized. The effect of the kind of polyaniline (PANI) dopant on the materials’ behavior was investigated, as well as the role of the conducting polymer in the pollutant abatement on the basis of its physico-chemical characteristics. Rhodamine B is removed by adsorption and/or photodegradation processes depending on the type of doping agent used for PANI protonation. The best materials were subjected to recycle tests in order to demonstrate their stability under the reaction conditions. The main transformation products formed during the photodegradation process were identified by ultraperformance liquid chromatography-mass spectrometry (UPLC/MS). The results demonstrated that photoactive floating PANI/TiO2 composites are useful alternatives to common powder photocatalysts for the degradation of cationic dyes.


Author(s):  
I. V. Pronina ◽  
E. S. Mochalova ◽  
Yu. A. Efimova ◽  
P. V. Postnikov

Objectives. Over the last decade, hematopoietic stimulants have grown increasingly popular in elite sports. This is supported by the growing number of high-profile doping scandals linked to their use. A group of these stimulants includes cobalt salts, which cause an increase in the oxygen capacity of the blood as well as a powerful stimulation of metabolic processes, resulting innoticeable competitive advantages. The use of cobalt salts is regulated according to the Prohibited List of the World Anti-Doping Agency (WADA). Currently, only a few works have been dedicated to solving the problem of detecting the abuse of cobalt salts in anti-doping control. Only a few laboratories have included cobalt salt determination in their methodological bases. The purpose of this review is to attract the attention of the scientific community to the toxicity of cobalt compounds, consequences of their intake, and pharmacokinetics, as well as the problems in their detection methods due to their widespread availability in the modern market and the growing number of abuse cases.Results. The main biological functions of cobalt, cellular levels of exposure, toxicity, and symptoms of cobalt salt poisoning are presented in detail in this review article. The data from the literature on the main methods for detecting cobalt as a doping agent have been generalized and systematized. There is a major focus on the amount of cobalt in dietary supplements that could cause an athlete to test positive for cobalt when they are consumed.Conclusions. After analyzing promising cobalt detection approaches and methods, it was determined that high-performance liquid chromatography in combination with inductively coupled plasma mass spectrometry has an undeniable advantage for detecting cobalt as a doping agent. The lack of explicit WADA requirements for detection methods and the lack of its obligation to determine cobalt make it tempting for unscrupulous athletes to use its salts. Therefore, antidoping laboratories must implement the abovementioned method as soon as possible.


2021 ◽  
Vol 22 (10) ◽  
pp. 5146
Author(s):  
Krystyna Głowacka ◽  
Anna Wiela-Hojeńska

Pseudoephedrine (PSE) is a drug with a long history of medical use; it is helpful in treating symptoms of the common cold and flu, sinusitis, asthma, and bronchitis. Due to its central nervous system (CNS) stimulant properties and structural similarity to amphetamine, it is also used for non-medical purposes. The substance is taken as an appetite reducer, an agent which eliminates drowsiness and fatigue, to improve concentration and as a doping agent. Due to its easier availability, it is sometimes used as a substitute for amphetamine or methamphetamine. Pseudoephedrine is also a substrate (precursor) used in the production of these drugs. Time will tell whether legal restrictions on the sale of this drug will reduce the scale of the problem associated with its misuse.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 658
Author(s):  
Daniela Valeria Tomasino ◽  
Mario Wolf ◽  
Hermes Farina ◽  
Gianluca Chiarello ◽  
Armin Feldhoff ◽  
...  

Poly(3,4-ethylenedioxythiophene) (PEDOT) plays a key role in the field of electrically conducting materials, despite its poor solubility and processability. Various molecules and polymers carrying sulfonic groups can be used to enhance PEDOT’s electrical conductivity. Among all, sulfonated polyarylether sulfone (SPAES), prepared via homogenous synthesis with controlled degree of sulfonation (DS), is a very promising PEDOT doping agent. In this work, PEDOT was synthesized via high-concentration solvent-based emulsion polymerization using 1% w/w of SPAES with different DS as dopant. It was found that the PEDOT:SPAESs obtained have improved solubility in the chosen reaction solvents, i.e., N, N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone and, for the first time, the role of doping agent, DS and polymerization solvents were investigated analyzing the electrical properties of SPAESs and PEDOT:SPAES samples and studying the different morphology of PEDOT-based thin films. High DS of SPAES, i.e., 2.4 meq R-SO3−× g−1 of polymer, proved crucial in enhancing PEDOT’s electrical conductivity. Furthermore, the DMSO capability to favor PEDOT and SPAES chains rearrangement and interaction results in the formation of a polymer film with more homogenous morphology and higher conductivity than the ones prepared from DMAc, DMF, and NMP.


2021 ◽  
Vol 22 ◽  
Author(s):  
Juliana de L. Castro ◽  
Henrique M. G. Pereira ◽  
Valéria P. de Sousa ◽  
Maria Elvira P. Martucci

Background: Dermorphin is a heptapeptide with an analgesic potential higher than morphine that does not present the same risk for the development of tolerance. These pharmacological features make dermorphin a potential doping agent in competitive sports and is already prohibited for racehorses. For athletes, the development of an efficient strategy to monitor for its abuse necessitates an investigation of the metabolism of dermorphin in humans. Methods: Here, human liver microsomes and zebrafish were utilized as model systems of human metabolism to evaluate the presence and kinetics of metabolites derived from dermorphin. Five hours after its administration, the presence of dermorphin metabolites could be detected in both models by liquid chromatography coupled to high resolution mass spectrometry. Results: Although the two models showed common results, marked differences were also observed in relation to the formed metabolites. Six putative metabolites, based on their exact masses of m/z 479.1915, m/z 501.1733, m/z 495.1657, m/z 223.1073, m/z 180.1017 and m/z 457.2085, are proposed to represent the metabolic pattern of dermorphin. The major metabolite generated from the administration of dermorphin in both models was YAFG-OH (m/z 457.2085), which is the N-terminal tetrapeptide previously identified from studies with rats. Conclusion: Its extensive characterization and commercial availability suggests that it could serve as a primary target analyte for the detection of dermorphin misuse. The metabolomics approach also allowed the assignment of other confirmatory metabolites.


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