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Displaying publications 21 - 26 of 26 in total

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Cu-Doped SnO₂ Nanoparticles: Synthesis and Properties

Sagadevan S, Chowdhury ZZ, Johan MRB, Aziz FA, Roselin LS, Podder J, et al.

J Nanosci Nanotechnol, 2019 Nov 01;19(11):7139-7148.
PMID: 31039868 DOI: 10.1166/jnn.2019.16666

In this work, a simple, co-precipitation technique was used to prepare un-doped, pure tin oxide (SnO₂). As synthesized SnO₂ nanoparticles were doped with Cu2+ ions. Detailed characterization was carried out to observe the crystalline phase, morphological features and chemical constituents with opto-electrical and magnetic properties of the synthesized nanoparticles (NPs). X-ray diffraction analysis showed the existence of crystalline, tetragonal structure of SnO₂. Both the sample synthesized here showed different crystalline morphology. The band gap energy (Eg) of the synthesized sample was estimated and it was found to decrease from 3.60 to 3.26 eV. The band gap energy reduced due to increase in Cu2+ dopant amount inside the SnO₂ lattice. Optical properties were analyzed using absorption spectra and Photoluminescence (PL) spectra. It was observed that Cu2+ ions incorporated SnO₂ NPs exhibited more degradation efficiencies for Rhodamine B (RhB) dye compared to un-doped sample under UV-Visible irradiation. The dielectric characteristics of un-doped, pure and Cu2+ incorporated SnO₂ nanoparticles were studied at different frequency region under different temperatures. The ac conductivity and impedance analysis of pure and Cu2+ incorporated SnO₂ nanoparticles was also studied. The magnetic properties of the synthesized samples were analysed. Both the sample showed ferromagnetic properties. The research indicated that the Cu2+ ions doping can make the sample a promising candidate for using in the field of optoelectronics, magneto electronics, and microwave devices.

Matched MeSH terms: Doping in Sports
Fulltext Knowledge and attitude related to nutritional supplements and risk of doping among national elite athletes in Malaysia

Balaravi, B., Chin, M.Q., Samantha Quah, L.W., Ramadas, A., Karppaya, H., Chai, W.J.

Malays J Nutr, 2017;23(3):409-423.
MyJurnal

Introduction: Often considered a legitimate strategy to enhance health and
performance, the consumption of nutritional supplements (NS) has become
a common practice which frequently results in unintentional doping among
athletes. Despite a probable association between NS and doping, there are limited
studies on this topic in developing countries such as Malaysia. Thus, this study
aimed to identify the prevalence of NS usage among national elite athletes and
assess their knowledge and attitude regarding its use and doping.

Methods:
This was a cross-sectional study conducted at the Malaysian National Sports
Institute among national elite athletes (n=50) recruited via convenience sampling.
The athletes completed a self-administered questionnaire documenting their
demographic characteristics, training information, NS consumption, knowledge
and attitude related to supplement-doping. The total knowledge and attitude
scores were compared according to demography, training information, and NS
consumption.

Results: The prevalence of NS use among the athletes was 72%.
NS usage was significantly associated with training duration (p=0.029), source of
nutrition information (p=0.047) and self-exploration on supplements (p=0.045).
Supplement-doping knowledge was significantly higher among athletes with
tertiary level education (p=0.027), NS users (p=0.044), those obtaining information
from nutritionists (p=0.048) and those who had attended nutrition workshops
(p

Matched MeSH terms: Doping in Sports
Monitoring recombinant human erythropoietin abuse among athletes

Citartan M, Gopinath SCB, Chen Y, Lakshmipriya T, Tang TH

Biosens Bioelectron, 2015 Jan 15;63:86-98.
PMID: 25058943 DOI: 10.1016/j.bios.2014.06.068

The illegal administration of recombinant human erythropoietin (rHuEPO) among athletes is largely preferred over blood doping to enhance stamina. The advent of recombinant DNA technology allowed the expression of EPO-encoding genes in several eukaryotic hosts to produce rHuEPO, and today these performance-enhancing drugs are readily available. As a mimetic of endogenous EPO (eEPO), rHuEPO augments the oxygen carrying capacity of blood. Thus, monitoring the illicit use of rHuEPO among athletes is crucial in ensuring an even playing field and maintaining the welfare of athletes. A number of rHuEPO detection methods currently exist, including measurement of hematologic parameters, gene-based detection methods, glycomics, use of peptide markers, electrophoresis, isoelectric focusing (IEF)-double immunoblotting, aptamer/antibody-based methods, and lateral flow tests. This review gleans these different strategies and highlights the leading molecular recognition elements that have potential roles in rHuEPO doping detection.

Matched MeSH terms: Doping in Sports/methods*
A novel antidoping and medical care delivery model at the 2nd Summer Youth Olympic Games (2014), Nanjing China

Mountjoy M, Akef N, Budgett R, Greinig S, Li G, Manikavasagam J, et al.

Br J Sports Med, 2015 Jul;49(13):887-92.
PMID: 25833900 DOI: 10.1136/bjsports-2014-094424

Antidoping and medical care delivery programmes are required at all large international multisport events.

Matched MeSH terms: Doping in Sports/prevention & control*
Use of UV-vis-NIR spectroscopy to monitor label-free interaction between molecular recognition elements and erythropoietin on a gold-coated polycarbonate platform

Citartan M, Gopinath SC, Tominaga J, Chen Y, Tang TH

Talanta, 2014 Aug;126:103-9.
PMID: 24881539 DOI: 10.1016/j.talanta.2014.03.043

Label-free-based detection is pivotal for real-time monitoring of biomolecular interactions and to eliminate the need for labeling with tags that can occupy important binding sites of biomolecules. One simplest form of label-free-based detection is ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, which measure changes in reflectivity as a means to monitor immobilization and interaction of biomolecules with their corresponding partners. In biosensor development, the platform used for the biomolecular interaction should be suitable for different molecular recognition elements. In this study, gold (Au)-coated polycarbonate was used as a platform and as a proof-of-concept, erythropoietin (EPO), a doping substance widely abused by the athletes was used as the target. The interaction of EPO with its corresponding molecular recognition elements (anti-EPO monoclonal antibody and anti-EPO DNA aptamer) is monitored by UV-vis-NIR spectroscopy. Prior to this, to show that UV-vis-NIR spectroscopy is a suitable method for measuring biomolecular interaction, the interaction between biotin and streptavidin was demonstrated via this strategy and reflectivity of this interaction decreased by 25%. Subsequent to this, interaction of the EPO with anti-EPO monoclonal antibody and anti-EPO DNA aptamer resulted in the decrease of reflectivity by 5% and 10%, respectively. The results indicated that Au-coated polycarbonate could be an ideal biosensor platform for monitoring biomolecular interactions using UV-vis-NIR spectroscopy. A smaller version of the Au-coated polycarbonate substrates can be derived from the recent set-up, to be applied towards detecting EPO abuse among atheletes.

Matched MeSH terms: Doping in Sports/prevention & control
Fulltext Synthesis and characterizations iron oxide carbon nanotubes nanocomposite by laser ablation for anti-microbial applications

Al-Salih M, Samsudin S, Arshad SS

J Genet Eng Biotechnol, 2021 May 18;19(1):76.
PMID: 34003402 DOI: 10.1186/s43141-021-00161-y

BACKGROUND: Environmental contamination by microbes is a major public health concern. A damp environment is one of the potential sources for microbe proliferation. Smart synthesis nanocatalytic coatings on surfaces, food, and material from different pathogen bacteria can inhibit using the Fe3O4/CNTs as anti-microbial growth can effectively curb this growing threat. In this present work, the anti-microbial efficacy of synthesis of a compound nanoparticle-containing iron oxide-multi-walled carbon nanotube was combined by laser ablation PLAL and explored the anti-bacterial action of colloidal solution of Fe3O4/CNTs NPs that was evaluated against bacteria which is classified as gram-negative (Escherichia coli (E. coli), Klebsiella pneumonia (K. pneumonia), and also that is identified as gram-positive (Streptococcus pyogenes (S .pyogenes) and Staphylococcus aureus (S. aureus) under visible light irradiation.
RESULTS: Doping of a minute fraction of iron(III) salt (0.5 mol%) in a volatile solvent (ethanol) was carried out via the sol-gel technique. Fe3O4 was further calcined at various temperatures (in the range of 500-700 °C) to evaluate the thermal stability of the Fe3O4 nanoporous oxidizer nanoparticles. The physicochemical properties of the samples were characterized through X-ray diffraction (XRD), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and UV-Visible spectroscopy techniques. XRD results revealed that the nanoparticles framework of Fe3O4 was maintained well up to 650 °C by the Fe dopant. UV-Vis results suggested that absorption property of combination Fe3O4/CNTs nanopowder by PLAL was enhanced and the band gap is reduced into 2.0 eV.
CONCLUSIONS: Density functional theory (DFT) studies emphasize the introduction of Fe+ and Fe2+ ions by replacing other ions in the CNT lattice, therefore creating oxygen vacancies. These further promoted anti-microbial efficiency. A significantly high bacterial inactivation that indicates results was evaluated and that the mean estimations of restraint were determined from triple assessment in every appraisal at 400 ml which represent the best anti-bacterial action against gram-positive and gram-negative microbes.

Matched MeSH terms: Doping in Sports