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1.
Materials (Basel) ; 17(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38998310

RESUMO

To meet the current demand for lead-free piezoelectric ceramics, a novel sol-gel synthesis route is presented for the preparation of Ba0.85Ca0.15Ti0.9Zr0.1O3 doped with cerium (Ce = 0, 0.01, and 0.02 mol%) and vanadium (V = 0, 0.3, and 0.4 mol%). X-ray diffraction patterns reveal the formation of a perovskite phase (space group P4mm) for all samples after calcination at 800 °C and sintering at 1250, 1350, and 1450 °C, where it is proposed that both dopants occupy the B site. Sintering studies show that V doping allows the sintering temperature to be reduced to at least 1250 °C. Undoped BCZT samples sintered at the same temperature show reduced functional properties compared to V-doped samples, i.e., d33 values increase by an order of magnitude with doping. The dissipation factor tan δ decreases with increasing sintering temperature for all doping concentrations, while the Curie temperature TC increases for all V-doped samples, reaching 120 °C for high-concentration co-doped samples. All results indicate that vanadium doping can facilitate the processing of BCZT at lower sintering temperatures without compromising performance while promoting thermal property stability.

2.
Behav Sci (Basel) ; 14(6)2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38920757

RESUMO

Interest in psychosocial predictors of doping has been increasing as a way of finding new approaches to reduce the use of performance-enhancing drugs. This investigation aimed to test the psychometric properties of an instrument to assess doping attitudes in Brazilian athletes. The PEAS was validated in Brazilian sports through a process of translation, back-translation and content validity assessment, presenting satisfactory evidence based on its content (CVC > 0.80). Then, 994 athletes from different sexes, types of sports and competitive levels answered the Brazilian version of the PEAS. The results showed satisfactory evidence of validity based on its response process, internal structure (X2/df = 2.04; RMSEA = 0.032 (0.026-0.038); CFI = 0.96; TLI = 0.95) and reliability (Cronbach's α, McDonald's ω and CR > 0.70). Network analysis was also used to further explore the PEAS's internal structure. Overall, the results provide support for the adoption of the PEAS for Brazilian athletes and possibly other Portuguese-speaking countries.

3.
Micromachines (Basel) ; 15(6)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38930770

RESUMO

p-type Ag-N dual acceptor doped ZnO thin films with long electrical stability were deposited by DC magnetron reactive co-sputtering technique. After deposition, the films were annealed at 400 °C for one hour in a nitrogen-controlled atmosphere. The deposited films were amorphous. However, after annealing, they crystallize in the typical hexagonal wurtzite structure of ZnO. The Ag-N dual acceptors were incorporated substitutionally in the structure of zinc oxide, and achieving that; the three samples presented the p-type conductivity in the ZnO. Initial electrical properties showed a low resistivity of from 1 to 10-3 Ω·cm, Hall mobility of tens cm2/V·s, and a hole concentration from 1017 to 1019 cm-3. The electrical stability analysis reveals that the p-type conductivity of the ZnO:Ag,N films is very stable and does not revert to n-type, even after 36 months of aging. These results reveal the feasibility of using these films for applications in short-wavelength or transparent optoelectronic devices.

4.
J Mol Model ; 30(4): 114, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558272

RESUMO

CONTEXT: Conjugated polymers (CPs) have been recognized as promising materials for the manufacture of electronic devices. However, further studies are still needed to enhance the electrical conductivity of these type of organic materials. The two main strategies for achieving this improvement are the doping process and chemical modification of the polymer chain. Therefore, in this article, we conduct a theoretical investigation, employing DFT calculations to evaluate the structural, energetic, and electronic properties of pristine and push-pull-derived poly(p-phenylene) oligomers (PPPs), as well as the analysis at the molecular level of the polymer doping process. As a primary conclusion, we determined that the PPP oligomer substituted with the push-pull group 4-EtN/CNPhNO2 exhibited the smallest HOMO-LUMO gap (Eg) among the studied oligomers. Moreover, we observed that the doping process, whether through electron removal or the introduction of the dopant anion ClO4-, led to a substantial reduction in the Eg of the PPP, indicating an enhancement in the polymer's electrical conductivity. METHODS: DFT calculations were conducted using the PBE0 functional along with the Pople's split valence 6-31G(d,p) basis set, which includes polarization functions on all atoms (B97D/6-31G(d,p)).

5.
Acta Ortop Bras ; 32(1): e273282, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38532870

RESUMO

Objective: To understand the Adverse Analytical Finding (AAF) that have occurred in Brazilian soccer in a recent 10-year period, comparing them to international data, to know the Brazilian profile. Methods: A review of the AAR in the Doping Control Commission database of the Brazilian Football Association from 2008 to 2017. The AAR in professional male soccer players between 2008 and 2017 were considered. Results: The sample selected in this research was composed of 40,092 doping tests, with 113 AAR, identified in 18 different competitions (0.28%) in the professional category, in Brazilian national and state competitions between 2008 and 2017, flagged in doping control exams through urine samples. Stimulants were detected most frequently (31.0%), followed by glucocorticoids (21.2%), diuretics, and masking agents (19.5%). The Brazilian Championship series did not show a relationship with any of the World Anti-Doping Agency (WADA) groups of substances. Series A showed 0.07% of AAR, Series B 0.21%, Series C 0.75% and Series D 1.49. Conclusion: The rate of AAR in Brazilian soccer was 0.28%, lower than the average for all soccer worldwide, and shows similar percentages among field positions. Stimulants were the most prevalent drugs. The national elite soccer competitions showed significantly fewer cases than the lower divisions. Level of Evidence II; Retrospective Study.


Objetivo: Compreender os Resultados Analíticos Adversos (RAA) ocorridos no futebol brasileiro nos últimos 10 anos, comparando-os aos dados internacionais, para conhecer o perfil do futebol brasileiro. Métodos: Revisão dos RAA no banco de dados da Comissão de Controle de Doping da Confederação Brasileira de Futebol de 2008 a 2017. Foram consideradas os RAA entre 2008 e 2017. Resultados: A amostra selecionada nesta pesquisa foi composta por 40.092 exames antidoping com 113 RAA, os quais foram identificados em 18 competições diferentes (0,28%) em atletas da categoria professional, entre 2008 e 2017, sinalizadas em exames de controle de doping através de amostras de urina. Estimulantes foram detectados com maior frequencia (31%), seguidos de glicocorticoides (21,2%), diuréticos e agentes mascarantes (19,5%). A série do Campeonato Brasileiro não apresentou relação com nenhum dos grupos de substâncias da World Anti-Doping Agency (WADA). A série A apresentou 0,07% da AAR, Série B 0,21%, Série C 0,75% e Série D 1,49%. Conclusão: A taxa de RAA no futebol brasileiro foi de 0,28%, inferior à media do futebol mundial e apresenta percentuais semelhantes entre as posições do campo. Os estimulantes foram as drogas mais prevalentes. As competições nacionais de futebol das Séries superiores apresentaram significativamente menos casos do que as inferiores. Nível de Evidência II; Estudo Retrospectivo.

6.
J Mol Model ; 30(4): 96, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446327

RESUMO

CONTEXT: Finding catalysts that do not rely on the use of expensive metals is one of the requirements to achieve sustainable production. The reactivity of graphene doped with 3d transition metals was studied. All dopants enhanced the reactivity of graphene and performed better than Stone-Wales defects and divacancies, but were inferior to monovacancies. For hydrogenation of doped-monovacancies, Sc, Ti, Cr, Co, and Ni induced more prominent reactivity on the carbon atoms. However, the metals were the most reactive center for V, Mn, and Fe-doped graphene. Cu and Zn turned the four neighboring carbon atoms into the preferred sites for hydrogenation. The addition of oxygen to doped graphene with Ti, V, Cr, Mn, Fe, Co, and Ni on a monovacancy revealed a more uniform pattern since the metal, preferred to react with oxygen. However, Sc induced a larger reactivity on the carbon atoms. The affinity of the 3d metal-doped graphene systems towards oxygen was inferior to that observed for single-vacancies. Therefore, vacancy engineering is the most favorable and least expensive method to enhance the reactivity of graphene. METHODS: We applied Truhlar's M06-L method accompanied by the 6-31G* basis sets to perform periodic boundary conditions calculations as implemented in Gaussian 09. The ultrafine grid was employed and the unit cells were sampled employing 100 k-points. Results were visualized employing Gaussview 5.0.1.

7.
ACS Appl Bio Mater ; 7(4): 2186-2196, 2024 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-38466818

RESUMO

Eumelanin is a natural pigment that can be particularly valuable for sustainable bioelectronic devices due to its inherent biocompatibility and hydration-dependent conductivity. However, the low conductivity of eumelanin limits its technological development. In this research, electrochemical doping was proposed as an alternative route to increase the electronic conductivity of synthetic eumelanin derivatives. Thin films of sulfonated eumelanin were deposited on platinum interdigitated electrodes and electrochemically treated by using cyclic voltammetry and chronoamperometry treatments. X-ray photoelectron spectroscopy analysis confirmed ion doping in sulfonated melanin. Current-voltage, current-time, and electrochemical impedance measurements were used to investigate the effect of different aqueous electrolytes (including KCl and LiClO4) treatments on the charge transport of sulfonated eumelanin. We show that the conductivity depends on the type and size of the anion used and can reach 10-3 S·cm-1. Additionally, depending on the electrolyte, there is a change in charge transport from mixed ionic/electronic to a predominantly electronic-only conduction. Our results show that the chemical nature of the ion plays an important role in the electrochemical doping and, consequently, in the charge transport of eumelanin. These insights serve as inspiration to explore the use of alternative electrolytes with different compositions further and develop eumelanin-based devices with tunable conductivities.


Assuntos
Alcanossulfonatos , Melaninas , Condutividade Elétrica , Eletrônica , Eletrólitos
8.
Molecules ; 29(2)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38257303

RESUMO

We present a study on the green synthesis of undoped and Er-doped ZnO compounds using Mangifera indica gum (MI). A set of tests were conducted to assess the structure of the material. The tests included X-ray diffraction, Raman, and Fourier-transform infrared spectroscopy. Optical properties were studied using diffuse reflectance and photoluminescence. Morphological and textural investigations were done using SEM images and N2 adsorption/desorption. Furthermore, photocatalytic tests were performed with methylene blue (MB), yellow eosin (EY), and the pharmaceutical drug ibuprofen (IBU) under UV irradiation. The study demonstrated that replacing the stabilizing agent with Mangifera indica gum is an effective method for obtaining ZnO nanoparticles. Additionally, the energy gap of the nanoparticles exhibits a slight reduction in value. Photoluminescence studies showed the presence of zinc vacancies and other defects in both samples. In the photocatalytic test, the sample containing Er3+ exhibited a degradation of 99.7% for methylene blue, 81.2% for yellow eosin, and 52.3% for ibuprofen over 120 min. In the presence of methyl alcohol, the degradation of MB and EY dyes is 16.7% and 55.7%, respectively. This suggests that hydroxyl radicals are responsible for the direct degradation of both dyes. In addition, after the second reuse, the degradation rate for MB was 94.08%, and for EY, it was 82.35%. For the third reuse, the degradation rate for MB was 97.15%, and for EY, it was 17%. These results indicate the significant potential of the new semiconductor in environmental remediation applications from an ecological synthesis.


Assuntos
Mangifera , Nanopartículas , Óxido de Zinco , Amarelo de Eosina-(YS) , Azul de Metileno , Fotólise , Ibuprofeno , Corantes
9.
Drug Test Anal ; 16(1): 38-48, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37161689

RESUMO

Dietary supplements (DS) are intended for healthy people to maintain or improve their overall health. Its consumption is widespread in large part of the general population and at all levels of athletes. Nevertheless, DS use can also pose health risks to individuals and, in the case of athletes, may lead to adverse analytical findings (AAFs) due to the possibility of DS contamination or adulteration with doping agents banned by the World Anti-Doping Agency. Although educational initiatives are being performed in Brazil to warn the sports community about inadvertent doping cases, AAFs connected to the DS administration have been increasingly growing. The findings of DS analyzed by the Brazilian Doping Control Laboratory (LBCD), between 2017 and 2022, after Testing Authorities (TAs) analysis requests, showed an alarming number of tainted samples. Diuretics were the most common adulterants found in all supplement types. However, the profile of prohibited substances in manufactured and compounded dietary supplements (MDS and CDS, respectively) were distinct, with stimulants being most prevalent in MDS and anabolic agents in CDS products. Additionally, MDS samples generally presented higher estimated concentrations of banned substances (mg/g) than CDS samples (µg/g). The common practice of DS intake by athletes continues to be of great concern for a doping-free sport, given the high prevalence of prohibited substances detected in the analyzed samples by the LBCD. The current Brazilian scenario reinforces the importance of raising awareness in the sports community of the possible consequences of an unintentional doping case linked to DS use.


Assuntos
Dopagem Esportivo , Esportes , Humanos , Brasil , Diuréticos/análise , Atletas , Suplementos Nutricionais/análise
10.
Environ Pollut ; 343: 123195, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142811

RESUMO

Organophosphorus pesticides (OPPs) such as parathion have extensive uses in agriculture and household applications. Chronic exposure to these pesticides can cause severe health and environmental issues. Therefore, a current ecological concern is associated with accumulating these noxious OPPs in food and water sources. In this work, a new Tb3+-doped Zn-LMOF (Zn-LMOF= (3D) {[Zn3(1,4 benzenedicarboxylate)3(EtOH)2]·(EtOH)0.6}∞) was synthesized by a solvent-free reaction between the Zn-LMOF and the salt TbCl3·6H2O using a high-speed ball milling. The Tb@Zn-LMOF was thoroughly characterized by multiple spectroscopic tools, including Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy, and studied in-depth as a luminescent sensor for a series of pesticides (parathion, malathion, methalaxil, carbofuran, iprodione, captan and glyphosate) in aqueous methanol. The Tb@Zn-LMOF is a long-lived green-emitting compound with luminescence originated by an efficient antenna effect from the excited energy levels of Zn-LMOF toward the 5D state of Tb3+ ions, as it is displayed by its strong emission bands at 488, 545, 585, and 620 nm and a lifetime of 1.01 ms upon excitation at 290 nm. Additions of pesticides to a neutral methanolic dispersion of Tb@Zn-LMOF modified its green emission intensity with a pronounced selectivity toward parathion within the micromolar concentration range. The detection limit for parathion was calculated to be 3.04 ± 0.2 µM for Tb@Zn-LMOF. Based on 31P NMR and mass spectrometry studies, it is attributed to the release of lanthanide ions from Tb@Zn-LMOF with the simultaneous formation of a Tb3+-parathion complex.


Assuntos
Estruturas Metalorgânicas , Paration , Praguicidas , Estruturas Metalorgânicas/química , Luminescência , Praguicidas/análise , Compostos Organofosforados , Íons/análise , Zinco
11.
Acta ortop. bras ; Acta ortop. bras;32(1): e273282, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1549993

RESUMO

ABSTRACT Objective: To understand the Adverse Analytical Finding (AAF) that have occurred in Brazilian soccer in a recent 10-year period, comparing them to international data, to know the Brazilian profile. Methods: A review of the AAR in the Doping Control Commission database of the Brazilian Football Association from 2008 to 2017. The AAR in professional male soccer players between 2008 and 2017 were considered. Results: The sample selected in this research was composed of 40,092 doping tests, with 113 AAR, identified in 18 different competitions (0.28%) in the professional category, in Brazilian national and state competitions between 2008 and 2017, flagged in doping control exams through urine samples. Stimulants were detected most frequently (31.0%), followed by glucocorticoids (21.2%), diuretics, and masking agents (19.5%). The Brazilian Championship series did not show a relationship with any of the World Anti-Doping Agency (WADA) groups of substances. Series A showed 0.07% of AAR, Series B 0.21%, Series C 0.75% and Series D 1.49. Conclusion: The rate of AAR in Brazilian soccer was 0.28%, lower than the average for all soccer worldwide, and shows similar percentages among field positions. Stimulants were the most prevalent drugs. The national elite soccer competitions showed significantly fewer cases than the lower divisions. Level of Evidence II; Retrospective Study.


RESUMO Objetivo: Compreender os Resultados Analíticos Adversos (RAA) ocorridos no futebol brasileiro nos últimos 10 anos, comparando-os aos dados internacionais, para conhecer o perfil do futebol brasileiro. Métodos: Revisão dos RAA no banco de dados da Comissão de Controle de Doping da Confederação Brasileira de Futebol de 2008 a 2017. Foram consideradas os RAA entre 2008 e 2017. Resultados: A amostra selecionada nesta pesquisa foi composta por 40.092 exames antidoping com 113 RAA, os quais foram identificados em 18 competições diferentes (0,28%) em atletas da categoria professional, entre 2008 e 2017, sinalizadas em exames de controle de doping através de amostras de urina. Estimulantes foram detectados com maior frequencia (31%), seguidos de glicocorticoides (21,2%), diuréticos e agentes mascarantes (19,5%). A série do Campeonato Brasileiro não apresentou relação com nenhum dos grupos de substâncias da World Anti-Doping Agency (WADA). A série A apresentou 0,07% da AAR, Série B 0,21%, Série C 0,75% e Série D 1,49%. Conclusão: A taxa de RAA no futebol brasileiro foi de 0,28%, inferior à media do futebol mundial e apresenta percentuais semelhantes entre as posições do campo. Os estimulantes foram as drogas mais prevalentes. As competições nacionais de futebol das Séries superiores apresentaram significativamente menos casos do que as inferiores. Nível de Evidência II; Estudo Retrospectivo.

12.
ACS Appl Mater Interfaces ; 15(47): 55030-55042, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37943615

RESUMO

The comprehension of side effects caused by high-temperature thermal treatments in the design of (photo)electrodes is essential to achieve efficient and cost-effective devices for solar water splitting. This investigation explores the beneficial and damaging impacts of thermal treatments in the (photo)electrode design, unraveling the impact of self-diffusion and its consequences. The industrial-friendly polymeric precursor synthesis (PPS) method, which is known for its easy technological application, was chosen as the fabrication technique for hematite photoabsorbers. For substrate evaluation, two types of conductive glass substrates, aluminum borosilicate and quartz, both coated with fluorine-doped tin oxide (ABS/FTO and QTZ/FTO, respectively), were subjected to thermal treatments following the PPS protocol. Optical and structural analyses showed no significant alterations in substrate properties, whereas X-ray photoelectron spectroscopy (XPS) revealed the migration of silicon and calcium ions from the glass component to the FTO surface. This diffusion can be further mitigated by an oxide buffer layer. To track the potential ion diffusion on the photoabsorber surface and assess its effect on the photoelectrode performance, hematite was selected as the model material and deposited onto the glass substrates. From all the ions that could possibly migrate, only Si4+ and Ca2+ originating from the glass component, as well as Sn4+ from the fluorine-doped tin oxide (FTO), were detected on the surface of the hematite photoabsorber. Interestingly, the so-called "self-diffusion" of these ions did not result in any beneficial effect on the hematite photoelectrochemical response. Instead, intentional modifications showed more substantial impacts on the photoelectrochemical efficiency compared to unintentional self-diffusion. Therefore, "self-diffusion", which can unintentionally dope the hematite, is not sufficient to significantly impact the final photocurrent. These findings emphasize the importance of understanding the true effect of thermal treatments on the photoelectrode properties to unlock their full potential in photoelectrochemical applications.

13.
Nanomaterials (Basel) ; 13(21)2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37947677

RESUMO

In this study, we created a series of N, S, and P-doped and co-doped carbon catalysts using a single graphene nanoribbon (GNR) matrix and thoroughly evaluated the impact of doping on ORR activity and selectivity in acidic, neutral, and alkaline conditions. The results obtained showed no significant changes in the GNR structure after the doping process, though changes were observed in the surface chemistry in view of the heteroatom insertion and oxygen depletion. Of all the dopants investigated, nitrogen (mainly in the form of pyrrolic-N and graphitic-N) was the most easily inserted and detected in the carbon matrix. The electrochemical analyses conducted showed that doping impacted the performance of the catalyst in ORR through changes in the chemical composition of the catalyst, as well as in the double-layer capacitance and electrochemically accessible surface area. In terms of selectivity, GNR doped with phosphorus and sulfur favored the 2e- ORR pathway, while nitrogen favored the 4e- ORR pathway. These findings can provide useful insights into the design of more efficient and versatile catalytic materials for ORR in different electrolyte solutions, based on functionalized carbon.

15.
Heliyon ; 9(10): e20809, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37860572

RESUMO

In the herein report, we synthesized ZnO thin films doped with manganese (Mn). We studied the impact of Mn doping loads (1 %, 3 %, 5 % wt.) on physicochemical properties of the compounds. Furthermore, we presented the photocatalytic efficiency in removal of methylene blue dye. The structural assay indicated ZnO conserve the wurtzite crystalline structure after dopant insertion. Furthermore, the crystalline size of catalysts was reduced after dopant incorporation. The SEM analysis showed a change in surface morphology after modification of ZnO thin films. Furthermore, Raman spectroscopy verified the Mn insertion inside the ZnO lattice. After the doping process, band gap was reduced by 16 %, in comparison to bare ZnO. After the photocatalytic test, the doped catalysts showed better performance than bare ZnO in removing MB. The best test showed a kinetics constant value of 2.9 × 10-3 min-1 after 120 min of visible irradiation. Finally, the Mn(5 %):ZnO thin film was suitable after five degradation cycles, and the degradation process efficiency was reduced by 32%.

16.
J Mol Model ; 29(10): 327, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37773546

RESUMO

CONTEXT: Recent advances in nanomaterial synthesis and characterization have led to exploring novel 2D materials. The biphenylene network (BPN) is a notable achievement in current fabrication efforts. Numerical studies have indicated the stability of its boron nitride counterpart, known as BN-BPN. In this study, we employ computational simulations to investigate the electronic and structural properties of pristine and doped BN-BPN monolayers upon CO[Formula: see text] adsorption. Our findings demonstrate that pristine BN-BPN layers exhibit moderate adsorption energies for CO[Formula: see text] molecules, approximately [Formula: see text]0.16 eV, indicating physisorption. However, introducing one-atom doping with silver, germanium, nickel, palladium, platinum, or silicon significantly enhances CO[Formula: see text] adsorption, leading to adsorption energies ranging from [Formula: see text]0.13 to [Formula: see text]0.65 eV. This enhancement indicates the presence of both physisorption and chemisorption mechanisms. BN-BPN does not show precise CO[Formula: see text] sensing and selectivity. Furthermore, our investigation of the recovery time for adsorbed CO[Formula: see text] molecules suggests that the interaction between BN-BPN and CO[Formula: see text] cannot modify the electronic properties of BN-BPN before the CO[Formula: see text] molecules escape. METHODS: We performed density functional theory (DFT) simulations using the DMol3 code in the Biovia Materials Studio software. We incorporated Van der Waals corrections (DFT-D) within the Grimme scheme for an accurate representation. The exchange and correlation functions were treated using the Perdew-Burke-Ernzerhof (PBE) functional within the generalized gradient approximation (GGA). We used a double-zeta plus polarization (DZP) basis set to describe the electronic structure. Additionally, we accounted for the basis set superposition error (BSSE) through the counterpoise method. We included semicore DFT pseudopotentials to accurately model the interactions between the nuclei and valence electrons.

17.
Biomed Chromatogr ; 37(12): e5741, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37688464

RESUMO

Matrix effect and sample pretreatment significantly affect the percentage recovery of peptides in biological matrices, affecting the method robustness and accuracy. To counteract this effect, an internal standard (IS) is used; however, in most cases this is not available, which limits the analytical method. It is important to identify short peptides that can be used as ISs in the quantification of peptides in biological matrices. In this study, doping peptides GHRP-4, GHRP-5, GHRP-6, Sermorelin (1-11), Sermorelin (13-20) and Sermorelin (22-29) were synthesized using solid-phase peptide synthesis. Treatment with human blood, trypsin and chymotrypsin was used to determine the stability of the peptides. Products were evaluated using the high-performance liquid chromatography-diode array detector (HPLC-DAD) method. The analytical methodology and sample pretreatment were effective for the analysis of these molecules. A unique profile related to protein binding and enzymatic stability of each peptide was established. GHRP-4, GHRP-6 and Sermorelin (22-29) can be considered as in-house ISs as they were stable to enzyme and blood treatment and can be used for the quantification of peptides in biological samples. Peptides GHRP-6 and Sermorelin (22-29) were used to analyse a dimeric peptide (26 [F] LfcinB (20-30)2 ) in four different matrices to test these peptides as in-house IS.


Assuntos
Testes de Química Clínica , Dopagem Esportivo , Hormônio Liberador de Hormônio do Crescimento , Substâncias de Crescimento , Peptídeos/análise , Humanos , Soro/química , Estabilidade Proteica , Análise Química do Sangue/normas , Testes de Química Clínica/normas , Hormônio Liberador de Hormônio do Crescimento/análise , Substâncias de Crescimento/análise
18.
Drug Test Anal ; 15(11-12): 1392-1402, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37641464

RESUMO

Cobalt was included on the World Anti-Doping Agency Prohibited List in 2015 due to its effect on stimulus of erythropoiesis via stabilization of hypoxia-inducible factor. Although it has proven benefits for performance enhancement, the unavailability of inductively coupled plasma-mass spectrometry on routine of the accredited laboratories is a factor that reduces its applicability in anti-doping analysis. Therefore, an analytical method for quantification of urinary cobalt as its diethyldithiocarbamate complex by liquid chromatography coupled with high-resolution tandem mass spectrometry was developed and validated. Palladium was proposed as internal standard and rhodium as a complexation control. A microwave-assisted acid digestion of the urine samples was essential, not only to eliminate the matrix effect but mainly to avoid the non-specific bond of cobalt to endogenous molecules. A linear method was obtained over the studied range from a negative urine control to a spiked concentration of 25 ng/mL, with an estimated limit of quantification of 2.5 ng/mL, and an adequate combined standard uncertainty of 11.4%. Considering that all reagents are commercially available, the proposed strategy is feasible to be included on routine sample preparation. Monitoring urinary cobalt concentrations globally opens the perspective to support the anti-doping system to define a suitable threshold value and to understand its potential misuse by athletes seeking for performance improvement.


Assuntos
Líquidos Corporais , Dopagem Esportivo , Humanos , Espectrometria de Massas em Tandem/métodos , Cobalto/urina , Cromatografia Líquida/métodos , Manejo de Espécimes , Detecção do Abuso de Substâncias/métodos
19.
Cannabis Cannabinoid Res ; 8(6): 949-954, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37279460

RESUMO

The World Anti-Doping Agency (WADA) classifies cannabis, all phytocannabinoids, and synthetics as doping, except for CBD. For agency, a method for doping substance must meet two criteria: performance enhancement (ergogenicity), health risk, or violation of the spirit of sports. Cannabis is neither ergogenic nor ergolytic (performance worsens), and the health risks for athletes are overestimated after 20 years of research. The significant problem remains in the complex (and difficult interpretation) definition of the spirit of sports, which transcends the objectives of sports excellence (performance and injury prevention) for moral policing. This perspective presents an evidence-based counterargument recommending the removal of cannabis and phytocannabinoids from the WADA Prohibited List.


Assuntos
Cannabis , Dopagem Esportivo , Esportes , Humanos , Dopagem Esportivo/prevenção & controle , Atletas , Princípios Morais
20.
MHSalud ; 20(1): 158-160, Jan.-Jun. 2023.
Artigo em Inglês | LILACS, SaludCR | ID: biblio-1558369

RESUMO

Abstract: Sport raises the level of human physical activity within the limits of genetic traits. The results of gene therapy have attracted some to think of using its technologies to create an "indomitable athlete." World Anti-Doping Agency (WADA) applies uncertain genetic testing procedures to establish cases of this type of doping. Yet, if the results of these procedures are doubtful, then doubt must be interpreted in favor of the athlete concerned.


Resumen: El deporte eleva el nivel de actividad física humana dentro de los límites de los rasgos genéticos. Los resultados de la terapia génica han atraído a algunos a pensar en utilizar sus tecnologías para crear un 'atleta indomable'. La Agencia Mundial Antidopaje (AMA) aplica procedimientos de pruebas genéticas inciertos para establecer casos de este tipo de dopaje. Sin embargo, si los resultados de estos procedimientos son dudosos, entonces la duda debe interpretarse a favor del atleta en cuestión.


Resumo: O esporte eleva o nível da atividade física humana dentro dos limites dos traços genéticos. Os resultados da terapia genética têm atraído alguns a pensar em usar suas tecnologias para criar um "atleta indomável". A Agência Mundial Antidoping (WADA) aplica procedimentos incertos de testes genéticos para estabelecer casos deste tipo de dopagem. Entretanto, se os resultados desses procedimentos forem incertos, então a incerteza deve ser interpretada em favor do atleta em questão.


Assuntos
Humanos , Testes Genéticos , Dopagem Esportivo
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