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1.
Electromagn Biol Med ; 41(1): 52-59, 2022 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-34686066

RESUMO

Idiopathic environmental intolerance attributed to electromagnetic field (IEI-EMF) called electromagnetic hypersensitivity or electrosensitivity appeared in Polish society awareness due to a considerable change made at the end of 2019 in Polish telecommunication laws. The aims of the project were to access the prevalence of IEI-EMF in Poland and to define a reliable methodology to study this phenomenon. The first step was the internet survey performed at the end of 2018. The IEI-EMF prevalence estimated at the level of 39.7% suggested considerable bias affecting the results. The faults of the first approach were analysed and then a second study stage was performed as a telephone survey at the end of 2020. The latter survey allowed estimating the prevalence of IEI-EMF as less than 1.8%. These discrepancies in the results of both surveys were connected to the medium used in the first survey (Internet) indirectly causing that the group pooled was not representative. The second pitfall was the definition of the criteria used for an electrosensitive person classification. This is why the IEI-EMF prevalence was investigated in the second stage with the use of numerous criteria. The application of different criteria allowed for essential conclusions concerning the appropriate methodology for such kinds of studies. Corrections of the methodology before the second survey allowed reliable results consistent with the results obtained in similar studies performed in other countries. Our findings also show that the IEI-EMF frequency reports presented in the literature have to be treated carefully and with some dose of scepticism.


Assuntos
Sensibilidade Química Múltipla , Campos Eletromagnéticos/efeitos adversos , Humanos , Polônia/epidemiologia , Inquéritos e Questionários
2.
Electromagn Biol Med ; 39(4): 411-418, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32993394

RESUMO

BACKGROUND: Mobile phones constitute an important source of radiofrequency electromagnetic field (RF-EMF) for humans. Taking into account high sensitivity of sensory hair cells of the inner ear to endogenous and exogenous agents, the potential impact of mobile phone usage on auditory organs is of particular interest. AIM: The aim of the study was to evaluate the impact of short-term exposure to RF-EMF generated by a mobile phone during 15-minute simulated phone call on human hearing as measured by Transient Evoked Otoacoustic Emission (TEOAE) and Acoustic Admittance Testing (AAT). MATERIAL AND METHODS: Within-subject study was performed on 23 healthy volunteers. All of the participants underwent TEOAE and AAT before and immediately after 15-minute simulated phone call with the use of a standard, modern smartphone. Analyzed parameters included: static compliance of tympanic membrane, middle ear pressure, ipsi- and contralateral acoustic reflex thresholds and percentage of signal reproducibility in TEOAE for exposed and non-exposed ear. Additionally, the results were compared in subgroups distinguished basing on self-reported sensitivity to RF-EMF originating from mobile phones. RESULTS: No statistically significant differences were identified between results of TEOAE and AAT before and after exposure, both in exposed and non-exposed ear. The results of EMF sensitive and non-sensitive subjects were comparable in all performed tests. CONCLUSIONS: Short-term exposure to mobile phone electromagnetic field did not influence auditory functions as measured by Evoked Otoacoustic Emission test and Acoustic Admittance Testing.


Assuntos
Acústica , Percepção Auditiva/fisiologia , Percepção Auditiva/efeitos da radiação , Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Ondas de Rádio/efeitos adversos , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Emissões Otoacústicas Espontâneas/fisiologia , Fatores de Tempo , Adulto Jovem
3.
J Phys Chem B ; 115(13): 3698-707, 2011 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-21405036

RESUMO

The conformational properties of epothilone A have been analyzed in detail using electronic structure calculations to better understand the effect of intramolecular hydrogen bonding on the conformational energies of this highly potent anticancer molecule. Single-point second-order Møller-Plesset calculations done in vacuo at the MP2/6-31+G(d,p)//B3LYP/6-31+G(d,p) level yielded data on the relative stability of conformers that were more distinct than data obtained from the standard DFT model, although the structural trends are in fair agreement. We studied torsional profiles of both hydroxyl groups and sampled energies of the side chain and thiazole moiety rotamers within the whole set of all experimentally accessible conformers. The aldol hydrogen bonds, though relatively weak, generally contribute to the conformational profile, while dipole-dipole interactions, ester group puckering, transannular repulsions between hydrogen atoms, steric effects, and syn-pentane effects have a limited influence. A salient result of our calculations is the determination that the energy of the clustered exo conformer P01 lays 9.3 kcal/mol below that of the extended, experimental conformer P11, apparently due to the unconstrained, near linear 3-OH hydrogen bond to thiazole. Another finding to be noted is the corroboration of the remarkable ability of 3-OH to form transannular hydrogen bonding with the epoxide, which releases the conformational strain of the macroring and thus leads to extra stabilization energy within the endoW subset. Finally, we found that the general trend of the conformer populations of epothilone A obtained from conformational energies resembles those derived from experiments and can be used to interpret values of NMR vicinal coupling constants. The calculated geometries and energies provide essential data for further discussion of the mechanism of biological activity of epothilone A and might be of importance in the explanation of its ADME properties.


Assuntos
Antineoplásicos/química , Epotilonas/química , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Conformação Molecular , Termodinâmica , Tiazóis/química
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