998 resultados para Organic electronic
Resumo:
Objectifs: Dans certains pays, les cigarettes électroniques contenant de la nicotine (e-cigarettes) sont considérées comme des produits de consommation courante, sans régulation spécifique. Dans d'autres (comme en Suisse), la vente d'e-cigarettes contenant de la nicotine est interdite, malgré l'importante demande de nombreux fumeurs de pouvoir les obtenir. Au vu du manque de données scientifiques sur l'efficacité et la sécurité à long-terme de ces produits, les spécialistes de la lutte contre le tabagisme se trouvent divisés sur la question de leur régulation. Afin d'obtenir un consensus parmi ces experts que nous puissions transmettre aux autorités sanitaires, nous avons réalisé une étude d'avis d'experts sur le plan national. Méthode : Nous avons utilisé une méthodologie Delphi, à l'aide de questionnaires électroniques, afin de synthétiser l'opinion d'experts suisses sur la question de la cigarette électronique. Participants : 40 experts suisses représentant l'ensemble de la Suisse. Mesures : Nous avons mesuré le degré de consensus entre les experts au sujet de recommandations touchant à la régulation, la vente et l'utilisation de l'e-cigarette contenant de la nicotine, ainsi que leur opinion générale sur le produit. De nouvelles recommandations et déclarations ont été formulées en tenant compte des réponses et des commentaires des participants. Résultats : Un consensus entre les experts a établi que l'e-cigarette contenant de la nicotine devrait être accessible en Suisse, mais seulement dans des conditions spécifiques. La vente devrait être réservée aux adultes, en utilisant des standards de qualité, une limite de concentration maximale de nicotine, et être accompagnée d'une liste d'ingrédients autorisés. La publicité devrait être restreinte et l'utilisation de l'e- cigarette devrait être interdite dans les lieux publics. Conclusions : Ces recommandations permettent de regrouper trois principes : 1) le principe de réalité, étant donné que le produit est déjà disponible sur le marché ; 2) le principe de prévention, puisque l'e- cigarette procure une alternative au tabac pour les fumeurs actuels, et 3) le principe de précaution, afin de protéger les mineurs et les non-fumeurs, étant donné que les effets à long-terme ne sont pas encore connus. Les autorités suisses devraient mettre en place une législation spécifique afin d'autoriser l'e- cigarette contenant de la nicotine.
Resumo:
By reconstructing the nutrient balance of a Catalan v illage circa 1861-65 we examine the sustainability of organic agricultural sy stems in the northwest Mediterranean bioregion prior to the green rev olution and the question of whether the nutrients extracted f rom the soil were replenished. With a population density of 59 inhabitants per square km, similar to other northern European rural areas at that time, and a lower liv estock density per cropland unit, this v illage experienced a manure shortage. The gap was f illed by other labour-intensiv e way s of transf erring nutrients f rom uncultiv ated areas into the cropland. Key elements in this agricultural sy stem were v iney ards because they hav e f ew nutrient requirements, and woodland and scrublands as sources of relev ant amounts of nutrients collected in sev eral ways.
Resumo:
This study was aimed to analyze and assess the use and perception of electronic health records (EHRs) by nurses. The study sample included 113 nurses from different shifts of primary health facilities in Catalonia, Spain, devoted to adult as well as pediatric outpatients using EHRs throughout the year 2010. A majority of the sample (87.5%) were women and 12.5% were men. The average age was 44.27 years and the average time working in primary healthcare was 47.15 months. A majority (80.4%) received specific training on the use of the EHR and 19.6% did not. The use of the application required side technical support (mean: 3.42) and it is considered necessary to learn more about the performance of the application (mean: 3.50). The relationship between the average ratings that nurses have about the EHR and age shows that there is no statistically significant linear relationship (r = - 0.002, p-value = 0.984). As to how long they have used the EHRs, there are significant differences (r= -0.304, p-value = 0.00), so the more time the nurse takes using the EHR, the greater degree of satisfaction is shown. In addition, there are significant differences between nurses" perceptions regarding the EHR and gender (t = - 0.421, p-value = 0.675). Nurses assessed as positive the contribution of the EHRs in their nursing care day work (average score: 2.55/5). Considering that the usability of the EHR device is assessed as satisfactory, the results of the perception of nurses show that we must also take into account the training and emphasize the need for a side technical support in the implementation process of the EHR. Doing so, the positive perception that nurses have in regard to information and communication technology in general and with respect to the EHR in particular may be increased.
Resumo:
The evolution of cooperation is thought to be promoted by pleiotropy, whereby cooperative traits are coregulated with traits that are important for personal fitness. However, this hypothesis faces a key challenge: what happens if mutation targets a cooperative trait specifically rather than the pleiotropic regulator? Here, we explore this question with the bacterium Pseudomonas aeruginosa, which cooperatively digests complex proteins using elastase. We empirically measure and theoretically model the fate of two mutants-one missing the whole regulatory circuit behind elastase production and the other with only the elastase gene mutated-relative to the wild-type (WT). We first show that, when elastase is needed, neither of the mutants can grow if the WT is absent. And, consistent with previous findings, we show that regulatory gene mutants can grow faster than the WT when there are no pleiotropic costs. However, we find that mutants only lacking elastase production do not outcompete the WT, because the individual cooperative trait has a low cost. We argue that the intrinsic architecture of molecular networks makes pleiotropy an effective way to stabilize cooperative evolution. Although individual cooperative traits experience loss-of-function mutations, these mutations may result in weak benefits, and need not undermine the protection from pleiotropy.
Resumo:
This study was aimed to analyze and assess the use and perception of electronic health records (EHRs) by nurses. The study sample included 113 nurses from different shifts of primary health facilities in Catalonia, Spain, devoted to adult as well as pediatric outpatients using EHRs throughout the year 2010. A majority of the sample (87.5%) were women and 12.5% were men. The average age was 44.27 years and the average time working in primary healthcare was 47.15 months. A majority (80.4%) received specific training on the use of the EHR and 19.6% did not. The use of the application required side technical support (mean: 3.42) and it is considered necessary to learn more about the performance of the application (mean: 3.50). The relationship between the average ratings that nurses have about the EHR and age shows that there is no statistically significant linear relationship (r = - 0.002, p-value = 0.984). As to how long they have used the EHRs, there are significant differences (r= -0.304, p-value = 0.00), so the more time the nurse takes using the EHR, the greater degree of satisfaction is shown. In addition, there are significant differences between nurses" perceptions regarding the EHR and gender (t = - 0.421, p-value = 0.675). Nurses assessed as positive the contribution of the EHRs in their nursing care day work (average score: 2.55/5). Considering that the usability of the EHR device is assessed as satisfactory, the results of the perception of nurses show that we must also take into account the training and emphasize the need for a side technical support in the implementation process of the EHR. Doing so, the positive perception that nurses have in regard to information and communication technology in general and with respect to the EHR in particular may be increased.
Resumo:
Combining headspace (HS) sampling with a needle-trap device (NTD) to determine priority volatile organic compounds (VOCs) in water samples results in improved sensitivity and efficiency when compared to conventional static HS sampling. A 22 gauge stainless steel, 51-mm needle packed with Tenax TA and Carboxen 1000 particles is used as the NTD. Three different HS-NTD sampling methodologies are evaluated and all give limits of detection for the target VOCs in the ng L−1 range. Active (purge-and-trap) HS-NTD sampling is found to give the best sensitivity but requires exhaustive control of the sampling conditions. The use of the NTD to collect the headspace gas sample results in a combined adsorption/desorption mechanism. The testing of different temperatures for the HS thermostating reveals a greater desorption effect when the sample is allowed to diffuse, whether passively or actively, through the sorbent particles. The limits of detection obtained in the simplest sampling methodology, static HS-NTD (5 mL aqueous sample in 20 mL HS vials, thermostating at 50 °C for 30 min with agitation), are sufficiently low as to permit its application to the analysis of 18 priority VOCs in natural and waste waters. In all cases compounds were detected below regulated levels
Resumo:
This study aimed at comparing the efficiency of various sampling materials for the collection and subsequent analysis of organic gunshot residues (OGSR). To the best of our knowledge, it is the first time that sampling devices were investigated in detail for further quantitation of OGSR by LC-MS. Seven sampling materials, namely two "swab"-type and five "stub"-type collection materials, were tested. The investigation started with the development of a simple and robust LC-MS method able to separate and quantify molecules typically found in gunpowders, such as diphenylamine or ethylcentralite. The evaluation of sampling materials was then systematically carried out by first analysing blank extracts of the materials to check for potential interferences and determining matrix effects. Based on these results, the best four materials, namely cotton buds, polyester swabs, a tape from 3M and PTFE were compared in terms of collection efficiency during shooting experiments using a set of 9 mm Luger ammunition. It was found that the tape was capable of recovering the highest amounts of OGSR. As tape-lifting is the technique currently used in routine for inorganic GSR, OGSR analysis might be implemented without modifying IGSR sampling and analysis procedure.
Resumo:
The pulsed dielectric barrier discharge (PDBD) and pulsed corona discharge (PCD) were compared for their efficiency to degrade phenol in water solution. Results show that PCD has higher efficiency than PDBD to degrade phenol. When initial pH of water solution was elevated, phenol degradation in the PCD reactor was significantly enhanced, although no considerable effect was seen in the PDBD reactor. The PCD reactor was also able to degrade lignin significantly, both in synthetically prepared solution and in pulp and paper mill wastewater. Water temperature did not affect phenol degradation; however, lignin was better oxidized at lower temperature.
Resumo:
In this work we report the obtention of a tetrabutylammonium hydroxide (TBAOH) solution in acetonitrile in a one pot process in order to study the interaction ironporphyrinOH- in non-aqueous systems. All the reactions were carried out under dry argon atmosphere to prevent the contamination of the solution with CO2, which leads to the formation of (TBA)2CO3.
Resumo:
Needle trap devices (NTDs) are a relatively new and promising tool for headspace (HS) analysis. In this study, a dynamic HS sampling procedure is evaluated for the determination of volatile organic compounds (VOCs) in whole blood samples. A full factorial design was used to evaluate the influence of the number of cycles and incubation time and it is demonstrated that the controlling factor in the process is the number of cycles. A mathematical model can be used to determine the most appropriate number of cycles required to adsorb a prefixed amount of VOCs present in the HS phase whenever quantitative adsorption is reached in each cycle. Matrix effect is of great importance when complex biological samples, such as blood, are analyzed. The evaluation of the salting out effect showed a significant improvement in the volatilization of VOCs to the HS in this type of matrices. Moreover, a 1:4 (blood:water) dilution is required to obtain quantitative recoveries of the target analytes when external calibration is used. The method developed gives detection limits in the 0.020–0.080 μg L−1 range (0.1–0.4 μg L−1 range for undiluted blood samples) with appropriate repeatability values (RSD < 15% at high level and <23% at LOQ level). Figure of merits of the method can be improved by using a smaller phase ratio (i.e., an increase in the blood volume and a decrease in the HS volume), which lead to lower detection limits, better repeatability values and greater sensibility. Twenty-eight blood samples have been evaluated with the proposed method and the results agree with those indicated in other studies. Benzene was the only target compound that gave significant differences between blood levels detected in volunteer non-smokers and smokers
Resumo:
In the present paper some general aspects of metal complex catalysis and its applications for oxyfunctionalization of various olefins, including naturally occurring ones, via selective oxidation, hydroformylation and alkoxycarbonylation are discussed.
Resumo:
In this work, using the EPR spectroscopy, we analysed the thermal stability of some organic-mineral compounds found in a Gleysoil from Rio Janeiro. It was observed a complete disappearance of the EPR signal around 600 °C for the < 2 µm fraction and a residual EPR signal of semiquinone free radical for the 2-20 µm and 20-53 µm fractions at the same temperature. Also, the experiments showed that the 2-20 µm fraction had a larger concentration of semiquinone free radical per g of carbon and a smaller line width indicated a larger humification of this fraction. This is an evidence that the soil organic matter of this fraction (2-20 µm) is more stable than the other ones.