RESUMO
BACKGROUND: Outdoor moulds are classically associated with exacerbations of asthma. OBJECTIVE: The aim of this paper was to examine nasal allergy morbidity by studying the short-term relationship between mould spore exposure and daily sales of reimbursable anti-allergic treatment in central France. METHODS: The relationship between daily changes in mould concentrations and daily sales obtained from the national healthcare database was analysed with generalized additive models, taking into account confounding factors such as air pollution, weather conditions, pollen counts, and days of the week. RESULTS: During the study, the average total yearly number of treated people was around 10 000 over approximately 230 000 surveyed. The relative risk (95% CI confidence interval) of sales of oral antihistamines with topical treatment associated with an interquartile increase in mould concentration was significant for Cladosporium 1.079 [1.019-1.142] and Aspergillus-Penicillium (Asp-Pen) 1.051 [1.021-1.082] in the whole population. When the influence of age and sex was considered, the relationship was significant only in male children aged 0-12 years and those aged between 13 and 49 years for Cladosporium: 1.256 [1.081-1.460] and 1.151 [1.063-1.245], respectively. The relationship was also significant for Asp-Pen: 1.038 [1.003-1.075] for those aged between 13 and 49 years and 1.056 [1.007-1.108] for adults over 50 years of age. CONCLUSION: The association between prescribed daily sales of oral antihistamines with topical treatment sales is associated with temporal changes to Cladosporium and Aspergillus-Penicillium in the whole population. When the influence of age and sex was considered, these two moulds contributed to prescribed medication sales only in the male general population.
Assuntos
Alérgenos/imunologia , Antialérgicos , Prescrições de Medicamentos/estatística & dados numéricos , Exposição Ambiental/efeitos adversos , Hipersensibilidade/epidemiologia , Hipersensibilidade/etiologia , Esporos Fúngicos/imunologia , Adolescente , Adulto , Antialérgicos/uso terapêutico , Criança , Pré-Escolar , Feminino , França/epidemiologia , Antagonistas dos Receptores Histamínicos/uso terapêutico , Humanos , Hipersensibilidade/tratamento farmacológico , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Pólen/efeitos adversos , Medição de Risco , Fatores de Risco , Adulto JovemRESUMO
Sewage treatment plants produce wastes resulting from the organic matter concentration in the form of sludge. A way of jointly treating and exploiting these increasing wastes jointly is the composting. Composting makes it possible to reduce volumes and the masses of wastes all while developing them in a product usable like organic soil enrichment. In this work, the composting process of an industrial sewage sludge composting plant was monitored to study the evolution of different physico-chemical parameters (temperature, moisture, pH, organic carbon, organic and inorganic nitrogen, organic carbon/organic nitrogen ratio, humic substances) and biochemical parameters (soluble fraction, hemicellulose, cellulose, lignin). Because these analyses are expensive and time consuming, we wanted to develop an alternative method to determine the maturity of compost related to compost properties with raw samples. Acceptable predictions were found for moisture, temperature, pH, organic carbon, organic carbon/organic nitrogen ratio, total-, organic- and ammoniacal nitrogen, fulvic- and humic acids and fulvic acids/humic acids ratio, but the error values were too high for the compost age to consider a quantification model. With regard to the biochemical parameters, this study is rather a preliminary test which shows the interest of the approach, but requires to be continued. Finally, the age of compost can be evaluated with Principal Component Analysis applied to NIR spectra.
Assuntos
Esgotos/química , Solo , Gerenciamento de Resíduos/métodos , Carbono/análise , Substâncias Húmicas/análise , Concentração de Íons de Hidrogênio , Análise dos Mínimos Quadrados , Nitrogênio/análise , Análise de Componente Principal , Espectroscopia de Luz Próxima ao Infravermelho , TemperaturaRESUMO
BACKGROUND: Temporal ecological studies have shown that outdoor moulds are associated with severe asthma exacerbations, as emergency department visits or hospitalisations. The aim of this was to assess the associations between daily sales of short-acting ß2-agonists (SABA), a specific and frequent treatment for control of mild asthma exacerbations in children and young adults, and outdoor mould concentrations in the central France area over a 5 year period. METHODS: The relationship between daily changes in mould (25 species) concentrations and daily SABA sales within a population of patients aged 6 to 39 years in a middle-size town of central France (approximately 127,000) was obtained from social security database and analysed with generalized additive models, taking into account confounding factors (air pollution, weather conditions, pollen counts and trend). RESULTS: Daily SABA sales (mean, SD) rose from 17.3 (9.7) in 2010 to 22.7 (12) in 2015. The relative risk (RR [95% CI]) of SABA sales associated with an interquartile increase in mould concentration was significant in the whole population for Alternaria 1.06 [1.002-1.12]. When the influence of age and sex was accounted for, the relationship was significant only in 6-12 years old males for Alternaria 1.21 [1.04-1.41] and Aspergillus-Penicillium 1.08 [1.04-1.12]. CONCLUSIONS: Daily SABA sales are positively associated with Alternaria spores in the general population of children and young adults. The association between daily SABA sales and temporal changes to Alternaria and Aspergillus-Penicillium in male children indicate that outdoor moulds contribute to asthma morbidity.
RESUMO
The combination of mid-infrared (MIR) spectroscopy with multivariate analysis provides an original approach to study the profile of virgin olive oils (VOOs) in relation to composition and geographical origin. Chemometric treatment of mid-infrared spectra (n=402) is assessed for quantification of fatty acids (14 components) and triacylglycerols (19 components) in VOO samples and for classification into six very geographically closed registered designations of origin (RDOs) of French VOO ("Aix-en-Provence", "Haute-Provence", "Vallée des Baux de Provence", "Nice", "Nîmes", and "Nyons"). Spectroscopic interpretation of regression vectors has shown that each RDO is correlated to one specific component of VOO according to their cultivar compositions. The results are satisfactory, in spite of the similarity of cultivar compositions between two denominations of origin ("Aix-en-Provence" and "Vallée des Baux de Provence"). Chemometric treatment of MIR spectra makes it possible to obtain similar results to those obtained by time-consuming analytical techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC) and constitutes a fast and robust tool for authentication of these French VOOs.
Assuntos
Lipídeos/análise , Óleos de Plantas/química , Ácidos Graxos/análise , França , Região do Mediterrâneo , Azeite de Oliva , Óleos de Plantas/normas , Espectrofotometria Infravermelho , Triglicerídeos/análiseRESUMO
The effect of pH on L-phenylalanine (L-phe) before and after exposure to near-infrared (NIR) radiation (15 min, 700-2000 nm) was investigated by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Characteristic bands of L-phe were described and the pK(a) values were retrieved from IR spectra by using an intensity ratio method according to our recent paper (Olsztynska et al., Appl. Spectrosc. 55, 901 (2001)). It has been found that the irradiation process modifies pK(a) values of L-phe. The spectroscopic study clearly shows the shift of acid-base equilibrium after exposure to NIR radiation. The phenomenon is due to modification of the water structure. Intra- and intermolecular hydrogen bonds weaken, which could induce conformational changes of the phe molecule. Subsequently, hydrophobic interactions strongly increase. These processes favor aggregation of phe molecules, which leads to deprotonation of the -NH(3)(+) to -NH(2) group and protonation of the -COO(-) to -COOH group, changing the pK(a) values.
Assuntos
Modelos Químicos , Fenilalanina/química , Fenilalanina/efeitos da radiação , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Simulação por Computador , Relação Dose-Resposta à Radiação , Concentração de Íons de Hidrogênio , Raios Infravermelhos , Cinética , Doses de RadiaçãoRESUMO
The water evaporation from L-phenylalanine (L-phe) aqueous solutions at different initial pH (0-13) was studied by vibrational spectroscopy. Next, the attenuated total reflection-Fourier transform infrared (ATR-FT-IR) spectra of aqueous solutions were compared to those recorded after drying for 72 h at 21 degrees C at appropriate initial pH values. Micro-Raman results collected after the water evaporation process are also presented and interpreted. Between pH = 2.5 and 8.76 a white non-transparent gel was observed, possibly due to the presence of the NaCl salt. The significant differences of the band intensities of L-phe functional groups noticed at pH near pK(a) values indicate the structural changes of L-phe molecules due to dimer formation (hydrogen bonds between the -COOH and -CO(2)(-) groups, and the -NH(3)(+) and -NH(2) groups). The presence of the hydrophobic interactions leads to the aggregation of L-phe molecules, most probably via phe-phe stacking as well as complexes of phe with Na(+) ions, HCl, or H(2)O molecules.
Assuntos
Fenilalanina/análise , Água/química , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Refratometria , Cloreto de Sódio/química , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral , VolatilizaçãoRESUMO
Lipid oxidation during olive oil storage induces changes in the metabolite content of the oil, which can be measured using so-called quality indices. High values indicate poor quality oils that should be labeled accordingly or removed from the market. Based on quality indices measured over two years for two olive oils, the AComDim method was used to highlight the influence of five factors (olive oil type, oxygen, light, temperature and storage time) on oxidative stability during storage. To identify the significant factors, two full factorial experimental designs were built, each containing four of the five factors examined. The results showed that all five factors, as well as some two-factor interactions, were significant. Phenols and hydroperoxides were identified as being the most sensitive to these factors, and potential markers for the ageing of olive oil.
Assuntos
Ácidos Graxos/análise , Armazenamento de Alimentos , Peróxidos Lipídicos/análise , Azeite de Oliva/análise , Fenóis/análise , Qualidade dos Alimentos , Luz , Azeite de Oliva/metabolismo , Oxirredução , Temperatura , Fatores de TempoRESUMO
Proton nuclear magnetic resonance spectroscopy ((1)H NMR), which has become an important tool for the study "in situ" of beta-cyclodextrin (beta-CD) complexes, was used to study and structurally characterize the inclusion complexes formed between beta-CD and isoproturon, fenuron, monuron and diuron. The high variation of the chemical shifts from the proton located inside the cavity (H-3, H-5 and H-6) coupled with the non variation of the one located outer sphere of the beta-CD (H-1, H-2 and H-4) provided clear evidence of the inclusion phenomena. Two-dimensional rotating frame Overhauser effect spectroscopy (ROESY) experiments were carried out to further support the proposed inclusion mode.
Assuntos
Diurona/química , Compostos de Metilureia/química , Compostos de Fenilureia/química , beta-Ciclodextrinas/química , Diurona/metabolismo , Espectroscopia de Ressonância Magnética , Compostos de Metilureia/metabolismo , Estrutura Molecular , Compostos de Fenilureia/metabolismo , beta-Ciclodextrinas/metabolismoRESUMO
Six Tunisian virgin olive oil (VOO) varieties, Chemlali Sfax, Chetoui, Chemchali, Oueslati, Zarrazi and Zalmati, were characterised by two analytical methods. The gas chromatography allowed the determination of 14 fatty acids and squalene amounts. With fatty acids of each variety, a characteristic "morphotypes" for each oil variety was established. Chemlali Sfax and Zalmati showed strong similarities. Gas chromatography of fatty acid methyl esters (FAME) and near infrared (NIR) spectra of oils, associated to chemometric treatment, allowed the study of the inter-varietal variability and the verification of the variety origins of some Tunisian commercial VOOs. The specificity of Tunisian VOOs was evaluated by comparing the samples to Algerian, Moroccan and French Protected Designation of Origin VOOs. Classification in varietal origins by SIMCA used the FAME compositions and NIR spectra of the most represented varieties (Chemlali Sfax, Chetoui and Oueslati) showed a high potential to authenticate the varietal origin of Tunisian VOOs.
Assuntos
Ácidos Graxos/análise , Contaminação de Alimentos/análise , Óleos de Plantas/química , África do Norte , Cromatografia Gasosa , França , Azeite de Oliva , Espectroscopia de Luz Próxima ao Infravermelho , TunísiaRESUMO
The interaction of diuron and isoproturon herbicides with beta-cyclodextrin is conducive to the formation of inclusion compounds in aqueous solution as well as in the solid state. The physico-chemical study of these complexes was carried out by various analytical techniques such as ultraviolet (UV), Fourier transform infrared (FT-IR), Raman, X-ray diffraction, and 1H-NMR (nuclear magnetic resonance) spectroscopies. The existence of inclusion complexes in water solution between the beta-cyclodextrin and each of the herbicides was revealed by electronic absorption and 1H-NMR spectroscopies. A 1:1 stoichiometry was determined for both complexes in aqueous medium from UV absorption spectra by using the Benesi-Hildebrand method; the relative stability constants at room temperature were calculated at 2700 +/- 300 L mol(-1) and 750 +/- 50 L mol(-1) for isoproturon and diuron, respectively. In the solid state, inclusion processes with beta-cyclodextrin were characterized by means of infrared and Raman techniques and confirmed by X-ray diffraction spectra.
Assuntos
Ciclodextrinas/química , Diurona/química , Herbicidas/química , Compostos de Metilureia/química , Compostos de Fenilureia , Espectrofotometria/métodos , beta-Ciclodextrinas , Ciclodextrinas/análise , Soluções , Processos Estocásticos , Água/química , Difração de Raios X/métodosRESUMO
The study of the behavior of heavy metals in soils requires the knowledge of the complexation between soil constituents and metals and this information is not available from conventional analytical techniques such as atomic absorption. Since metals do not absorb mid infrared radiation, we wanted to characterize them using their interaction with the organic matter of soils. The use of chemometrics treatment of the spectroscopic data has demonstrated firstly that the interaction between soil constituents and metals takes place preferentially via organic matter, secondly the high difference between the complexation of lead and zinc into organic matter should be noted. The study of the infrared spectra shows that two bands at 1670-1690 and 1710 cm(-1) vary according to the concentration of lead, which seems to be preferentially complexed by the salicylate functionality.
Assuntos
Substâncias Húmicas/química , Metais Pesados/química , Poluentes do Solo/análise , França , Chumbo/análise , Chumbo/química , Metais Pesados/análise , Análise de Regressão , Salicilatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Compostos de Zinco/análise , Compostos de Zinco/químicaRESUMO
A nanosecond transient absorption spectroscopy study of flavone performed with a 248 nm pump radiation has been investigated with the support of a chemometric treatment: SIMPLISMA. The experimental spectra obtained in various solvent with a pump-probe delay lower than about 2 micros are in quite good concordance with those already presented in the literature. Nevertheless after about 10 micros, the spectrum pattern significantly evolves as a function of time particularly for the methanolic solution. A qualitative analysis together with a SIMPLISMA chemometric treatment of the experimental data allowed to elucidate and characterise two interdependent transient species in the alcoholic medium: the lowest T1 triplet state of flavone and the ketyl radical forming by H-abstraction reaction from the solvent. In cyclohexane and acetonitrile, the same species seem to be produced in the studied time-scale but the radical form is generated with variable quantum yield depending on the solvent polarity. The pure spectrum and the photochemical kinetics of each reaction intermediate could have been determined with the help of the second derivative SIMPLISMA calculation procedure.
Assuntos
Flavonoides/química , Modelos Químicos , Solventes/química , Acetonitrilas/química , Cicloexanos/química , Flavonas , Cinética , Metanol/química , Fotoquímica , Software , Espectrofotometria Ultravioleta , TempoRESUMO
FTIR and Raman vibrational spectroscopic techniques as well as DFT quantum chemical calculation were used for characterizing conformational changes of phenylurea (a herbicide parent molecule) occurring from solid state to aqueous medium. Experimental infrared frequencies were assigned on the base of urea and benzenic derivatives spectroscopic data available in the literature and vibrational normal modes analytical calculation at the fully optimized geometry. Investigation of isotopic and solvent effects has revealed that the structure of phenylurea is particularly sensitive to the electrostatic environment via hydrogen non covalent bonds. The ability of beta-cyclodextrin (beta-CD) to form host-guest inclusion complex with phenylurea in the solid state was also evidenced by significant frequency shifts observed in the 1400-1800 cm(-1) spectral range.
Assuntos
Compostos de Fenilureia/química , beta-Ciclodextrinas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral RamanRESUMO
Radiation-induced decomposition of the anion exchange resin Amberlite IRA-400 in hydroxide form by gamma radiolysis has been studied under different irradiation doses and irradiation atmospheres. In this work, we focused on the degradation of the solid part of the resin by Fourier transformed infrared (FTIR) and (13)C nuclear magnetic resonance (NMR) spectroscopies associated with chemometric treatments. FTIR and (13)C NMR techniques showed that only -CH(2)N(+)(CH(3))(3) groups were detached from the resin whereas the polystyrene divinylbenzene backbone remains intact. The quaternary ammonium groups were replaced by amine or carbonyl groups according to the irradiation atmosphere (with or without water or oxygen). Principal components analysis (PCA) was used to classify the degraded resins according to their irradiation conditions by separating the effect of the dose or the environment. The PCA loadings have shown spectral regions which discriminate the irradiated resins whereas SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) allows to identify families of component characterizing the chemical structure of resins and estimate their relative contributions according to the irradiation atmospheres.
RESUMO
The development of near infrared (NIR) sensors has to go through different steps of testing. Once a prototype is ready to be used, it is necessary to evaluate and optimize the experimental conditions and the data collection, in terms of accuracy, repeatability, reproducibility and speed. This paper studies the effects of controllable experimental factors on the quality of the spectral response, to determine the influence of each instrumental parameter and to improve the predictions obtained from the collected data. The AComDim method, based on the multi-block analysis of ANOVA matrices, was used here to evaluate the impact of experimental factors on the responses from the different sensors tested.
RESUMO
This work investigates the potential use of simultaneously near-infrared (NIR) and mid-infrared (MIR) spectroscopies for the quantitative analysis of fatty acids and triacylglycerols and for identifying the Registered Designation of Origin (RDO) of extra virgin olive oils. The two spectral ranges were used separately using PLS and PLS-DA regressions. To combine both information, concatenated matrix was used at the first time, multiblock method using H-PLS models were constructed at the second time. The models were compared in terms of prediction errors. The results obtained with MIR spectroscopy are better than the ones obtained with NIR spectroscopy. The H-PLS methodology seems to be very interesting for quantitative analysis with the use of additional information in the NIR range, which is not present in the MIR one. For RDO identification by discriminant analysis, the use of multiblock method was less efficient.
RESUMO
The octane number rating of a gasoline gives an indication of the gasoline performances, under various engine conditions. Two different ratings are included: Research Octane Number (RON) and Motor Octane Number (MON). The standard laboratory method for octane number determination is the knock engine method in which a gasoline is burned and its combustion characteristics compared to known standards. This method is time consuming and labor intensive, and provides no ability for real time control of production. NIR can be applied in real time directly in process monitoring or as a laboratory procedure. Near infrared spectra of gasoline samples were collected thanks to four different short wavelengths near infrared analysers, built with strictly the same technology. The aim of this study was to transfer the calibration built on one spectrometer to the other ones. We applied the external parameter orthogonalisation (EPO) correction to get rid of the apparatus influence on information contained in spectra. By this method, we managed to improve prediction values of two major gasolines' properties, i.e. Research and Motor Octane Number.
RESUMO
One of the most suitable analytical techniques used for edible oil quality control is Fourier transform mid infrared spectroscopy (FT-MIR). FT-MIR spectroscopy was used to continuously characterize the aging of various edible oils thanks to a specific aging cell. There were differences in the spectra of fresh and aged oils from different vegetable sources, which provide the basis of a method to classify them according to the oxidative spectroscopic index value. The use of chemometric treatment such as multivariate curve resolution-alternative least square (MCR-ALS) made it possible to extract the spectra of main formed and degraded species. The concentration profiles gave interesting information about the ability of the various oils to support the oxidative treatment and showed that all oils present the same aging process. Both methods led to concordant results in terms of induction times determined by the oxidative spectroscopic index and the appearance of oxidation products revealed by MCR-ALS.
Assuntos
Análise de Alimentos , Óleos de Plantas/normas , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Conservação de Alimentos , Oxidantes , OxirreduçãoRESUMO
As the jojoba oil was used in cosmetic, pharmaceutical, dietetic food, animal feeding, lubrication, polishing and bio-diesel fields, it was important to study its aging at high temperature by oxidative process. In this work a FT-MIR methodology was developed for monitoring accelerate oxidative degradation of jojoba oils. Principal component analysis (PCA) was used to differentiate various samples according to their origin and obtaining process, and to differentiate oxidative conditions applied on oils. Two spectroscopic indices were calculated to report simply the oxidation phenomenon. Results were confirmed and deepened by multivariate curve resolution-alternative least square method (MCR-ALS). It allowed identifying chemical species produced or degraded during the thermal treatment according to a SIMPLISMA pretreatment.
Assuntos
Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Ceras/química , Temperatura Alta , Análise dos Mínimos Quadrados , Análise Multivariada , Oxirredução , Análise de Componente Principal , Software , Fatores de TempoRESUMO
The assessment of physico-chemical properties in forest soils affected by fires was evaluated using near infrared reflectance (NIR) spectroscopy coupled with chemometric methods. In order to describe the soil properties, measurements were taken of the total organic carbon on solid phase, the total nitrogen content, the organic carbon and the specific absorbences at 254 and 280 nm of humic substances, organic carbon in humic and fulvic acids, concentrations of NH(4)(+), Ca(2+), Mg(2+), K(+) and phosphorus in addition to NIR spectra. Then, a fire recurrence index was defined and calculated according to the different fires extents affecting soils. This calculation includes the occurrence of fires as well as the time elapsed since the last fire. This study shows that NIR spectroscopy could be considered as a tool for soil monitoring, particularly for the quantitative prediction of the total organic carbon, total nitrogen content, organic carbon in humic substances, concentrations of phosphorus, Mg(2+), Ca(2+) and NH(4)(+) and humic substances UVSA(254). Further validation in this field is necessary however, to try and make successful predictions of K(+), organic carbon in humic and fulvic acids and the humic substances UVSA(280). Moreover, NIR coupled with PLS can also be useful to predict the fire recurrence index in order to determine the spatial variability. Also this method can be used to map more or less burned areas and possibly to apply adequate rehabilitation techniques, like soil litter reconstitution with organic enrichments (industrial composts) or reforestation. Finally, the proposed recurrence index can be considered representative of the state of the soils.