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1.
Artigo em Inglês | MEDLINE | ID: mdl-30154301

RESUMO

As electronic cigarettes (e-cigarettes) represent a new constantly evolving product category, the systematic analysis of the developed devices and the e-liquid vaporization is challenging. Indeed, understanding how e-cigarettes work and the role of key parameters in the process are major issues. This work focuses on an experimental study of how the power supplied by the battery to the atomizer coil influences e-liquid consumption. The reproducibility and the repeatability of e-liquid consumption were investigated over 20 series of 20 puffs for one of the tested atomizers. Then, the reproducibility and the repeatability of the e-liquid consumption was investigated over five series of 20 puffs for each tested atomizer. The wire behavior according to the supplied power could be separated into three regimes: under-heating (insufficient power to generate an aerosol), optimal vaporization characterized by a linear trend (vaporization of the e-liquid proportional to the supplied energy) and over-heating (dry-burn occurs). Using a controllable and repeatable energy supply, the reproducibility of the quantity of vaporized e-liquid was verified for each of the five series of 20 puffs programed for all the atomizers except one. Finally, the influence of the supplied power on the vaporization and the consumption of the e-liquid as well as the optimal power ranges were investigated and discussed. The results showed that atomizers with resistance ranging from 1 Ω to 1.8 Ω are efficient using all the energy supplied by the battery to vaporize the e-liquid and reducing the energy lost in the cotton or in the metal part of atomizer coil.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina/instrumentação , Nebulizadores e Vaporizadores , Vaping , Aerossóis , Calefação , Reprodutibilidade dos Testes
2.
Magn Reson Chem ; 47(11): 989-93, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19603395

RESUMO

Three new pyranocoumarin derivatives, tamanolide (1), tamanolide D (2) and tamanolide P (3), were isolated from the almond seeds of Calophyllum inophyllum L. (Clusiaceae) grown in French Polynesia. These compounds, having an unprecedented C-4 isobutyl substituent, have been characterized as a new class of pyranocoumarins called tamanolides. Their structures were elucidated on the basis of 1D and 2D NMR techniques (COSY, NOESY, HSQC and HMBC) in association with MS (HR-ESI-MS) data analysis.


Assuntos
Calophyllum/química , Nozes/química , Extratos Vegetais/química , Piranocumarinas/química , Sementes/química , Espectroscopia de Ressonância Magnética , Polinésia , Piranocumarinas/análise , Piranocumarinas/classificação
3.
J Nutr Health Aging ; 6(3): 209-23, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11887247

RESUMO

Most of the many epidemiological studies in the field strongly suggest that an equilibrated diet such as the so-called "mediterranean diet", is associated with protective effects against major diseases, and particularly, against cardiovascular risks. Since many reports also consider reactive oxygen species or free radical oxidations to be responsible for the accompanying disorders of most pathologies as well as for ageing, it is conceivable that natural plant metabolites such as polyphenols, are likely to play an important role in insuring this protection. Indeed, not only their presence, in particularly high amounts and varieties in foods of such a diet, but also, inter alia, their very potent antioxidant or radical scavenging properties, make polyphenols best accounting for the parodoxical part of the french paradox . Therefore, many efforts have been made to assess the mechanisms for such a cardiovascular disease protection. Whatever convincing were the polyphenols properties demonstrated by many in vitro experiments to support those theories, quite a great number of the results appeared somewhat contradictory when transposed to humans, in the in vivo situation. Some people totally refute this explanation, thinking that health benefits, as far as alcoholic beverages are concerned, originate from ethanol but also, with no doubt, some polyphenols even revealing to be pro-oxidants .


Assuntos
Antioxidantes/administração & dosagem , Doenças Cardiovasculares/etiologia , Dieta , Flavonoides , Peroxidação de Lipídeos , Fenóis/administração & dosagem , Polímeros/administração & dosagem , Idoso , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Consumo de Bebidas Alcoólicas , Antioxidantes/metabolismo , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/prevenção & controle , Feminino , Humanos , Masculino , Oxirredução , Fenóis/análise , Fenóis/metabolismo , Polímeros/análise , Polímeros/metabolismo , Polifenóis , Fatores de Risco , Vinho
4.
J Biol Inorg Chem ; 6(1): 14-22, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11191219

RESUMO

The synthesis of a new tetrapyridyl ligand, bis[di-1,1-(2-pyridyl)ethyl]amine (BDPEA), is described. Complexation of this ligand with manganese(II), iron(III) or copper(II) chlorides afforded mononuclear complexes: Mn(BDPEA)Cl2 (1) [Fe (BDPEA)Cl2]Cl (2) and [Cu(BDPEA)Cl]Cl (3). In all cases, BDPEA is coordinated to the metal center by three pyridine nitrogen atoms and the secondary amine. The geometrical environments around the metals in Mn(BDPEA)Cl2 and [Fe(BDPEA)Cl2]Cl are best described as distorted octahedrals and in [Cu (BDPEA)Cl]Cl as a slightly distorted square pyramid. The DNA cleavage activities of manganese(II), iron (III) or copper(II) complexes of both BDPEA and another tetrapyridyl ligand, bis[di(2-pyridyl) methyl]amine (BDPMA), in the presence of an oxidant (H2O2) or a reducing agent (ascorbate) with air, are reported. The iron(III) complexes exhibited significantly enhanced efficiencies, compared to copper(II) complexes. [Fe(BDPEA)Cl2]Cl is found to be the most active DNA cleaver, in agreement with a better stability of BDPEA in oxidizing conditions.


Assuntos
Cobre/química , DNA/efeitos dos fármacos , Etilaminas/farmacologia , Ferro/química , Manganês/química , Piridinas/farmacologia , Cristalografia por Raios X , DNA/química , Estudos de Avaliação como Assunto , Hidrólise , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular
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