RESUMO
In this research work, an optimization of an environment friendly extraction method of cactus (Opuntia ficus indica) cladode dietary fibers was conducted. For this purpose, a central composite experimental design with two factors (temperature and time) and five levels was established. The basic objective of this optimization was to maximize fiber yield using hot water as an extraction eco-solvent. The optimum extraction time (330 min) and temperature (100 °C) were determined with a constant medium agitation rate. Additionally, this study also aimed at establishing the validation of the statistical model to carry out the extrapolation of the extraction process at the pilot scale. The fibers extracted at the pilot scale showed yields (45.2 ± 0.01%) in agreement with those obtained through the optimization and validation lab-scale steps (44.97 ± 0.02). Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD) and Scanning electron microscopy (SEM) analysis were conducted to investigate the structure and microstructure of pilot scale-produced fibers. FTIR spectrum and XRD pattern were typical to lignocellulosic fibers results. Sharp and thin peaks characteristic of cellulose were detected. Pure and crystallized phases were recorded with a 45% crystallinity index. SEM analysis presented elongated and organized cells with a uniform structure comparable to cellulosic fibers microstructure.
Assuntos
Opuntia , Opuntia/química , Fibras na Dieta/análise , Celulose , Extratos Vegetais/química , Microscopia Eletrônica de VarreduraRESUMO
Volatile organic compounds are species of concern for indoor air quality. They are emitted from a wide range of indoor sources and in particular from construction materials. Industrialized wood-based panels made from various types of wood bonded with thermosetting adhesive resins have been shown to emit volatile organic compounds over months or even years mostly due to the petrochemical binders. Some studies have been conducted on binderless panels, but they mainly focused on the pressing parameters to be applied to optimize the panel characteristics. The aim of this research is to document the emissions from binderless panels and to access the volatile composition of wood processing through the molding of materials. For this purpose, binderless boards were manufactured from hardwoods, known to emit less than softwoods with different thermopressing temperatures and times. Emissions were studied by placing the materials in microchambers. Volatile organic compounds were then sampled and analyzed by various chromatographic methods. On the other hand, materials were pyrolyzed and then analyzed by gas chromatography and mass spectrometry. The implemented protocols proved suitable for the determination of more than 40 organic compounds, among which are aldehydes, aromatics, furans and derivatives, and carboxylic acids.
Assuntos
Poluição do Ar em Ambientes Fechados , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas , Madeira/química , Poluição do Ar em Ambientes Fechados/análise , Aldeídos/análiseRESUMO
Due to their particular structural characteristics, the extraction and isolation of saponins from plants present a serious challenge. In this study, specific extraction protocols were first implemented to extract the secondary metabolites from Astragalus hamosus and, more precisely, the saponins. Subsequent purification of the extracts was based on a single chromatographic technique, high-performance thin-layer chromatography, applying two development systems: a one-step system that separated molecules according to their polarity and a multiple development system that made it possible to detect the triterpenoid saponins, azukisaponin or soyasapogenol at a retarded Rf of 0.2. The difficulties of detecting the Astragalus hamosus saponins encountered during the extraction and purification of the extracts have been highlighted and the strategy carried out to isolate the saponins has been discussed.
Assuntos
Astrágalo , Saponinas , Triterpenos , Astrágalo/química , Cromatografia em Camada Fina/métodos , Extratos Vegetais/química , Saponinas/química , Triterpenos/químicaRESUMO
This review addresses the issue of replacing manufactured microplastics in seed coatings used in agriculture. Firstly, it focuses on the policy and regulatory actions taken on microplastics at a global level. There is no consensus within the scientific community on the definition of a microplastic and, more generally, on the classification of plastic debris. Nevertheless, several decision schemes have been proposed in an attempt to define the notion of microplastics. The different criteria relevant to this definition, such as the size, physical state, chemical structure, origin, and persistence of microplastics, are discussed, with a comparison being made between the REACH regulation and the scientific literature. Seed production and processing are also discussed, with the functions of seed coatings being explained in order to gain a better understanding of the properties to be considered in a substitution strategy for currently used microplastics. The main challenges are multiple; substitutes must provide the same performance as microplastics: (i) improving the adherence of the treatment to the seed, (ii) distributing the treatment more evenly over the seed, (iii) reducing the amount of dust-off when handling treated seed, and (iv) improving the seed flowability, which is particularly important during the sowing stage, all while preserving the physiological properties of the seed. Substitute polymers are proposed according to the desired performance and functional properties: two main chemical families of biopolymers were identified in the literature: polysaccharides and proteins. Among them, 13 and 6 polymers, respectively, complied with REACH regulation, demonstrating adhesion, dust reduction performances, and preservation of seed physiological quality in particular. This work aims to guide future studies on microplastic substitution in seed coatings, and to highlight research needs in this area. It is based on an analysis and discussion of the literature, identifying and listing potential substitutes.
RESUMO
Due to the rapid increase in the world's population, many developing countries are facing malnutrition problems, including famine and food insecurity. Particularly, the deficiency of protein sources becomes a serious problem for human and animal nutrition. In this context, Single Cell Proteins, could be exploited as an alternative source of unconventional proteins. The aim of the study was to investigate SCP production and composition by Cupriavidus necator under various environmental conditions, temperature and pH values. A mono-factorial approach was implemented using batch bioreactor cultures under well-controlled conditions. Results were compared in terms of bacterial growth and SCP composition (proteins, nucleic acids, amino acids and elemental formula). Complementary analyses were performed by flow cytometry to study cell morphology, membrane permeability and the presence of Poly(3-hydroxybutyrate) (PHB) production. Our data confirmed the ability of C. necator to produce high amount of proteins (69â¯%DW at 30⯰C and pH7). The results showed that temperature and pH independently impact SCP production and composition. This impact was particularly observed at the highest temperature (40⯰C) and also the lowest pH value (pH5) providing lower growth rates, cell elongation, changes in granularity and lower amounts of proteins (down to 44â¯%DW at pH5) and nucleic acids. These low percentages were related to the production of PHB production (up to 44â¯%DW at 40⯰C) which is the first report of a PHB accumulation in C. necator under nutrient unlimited conditions.
Assuntos
Reatores Biológicos , Cupriavidus necator , Poliésteres , Temperatura , Cupriavidus necator/metabolismo , Cupriavidus necator/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Reatores Biológicos/microbiologia , Poliésteres/metabolismo , Proteínas de Bactérias/metabolismo , Hidroxibutiratos/metabolismo , Proibitinas , Aminoácidos/metabolismo , Poli-Hidroxibutiratos , Proteínas AlimentaresRESUMO
Cellulosic fibers obtained from Barley straw were utilized to reinforce PHB. Four different processed fibers were employed as reinforcing material: sawdust (SW), defibered (DFBF), delignified (DBF), and bleached (BBF) fibers. The composite was processed from two different perspectives: a discontinuous (bach) and an intensification process (extrusion). Once processed and transformed into final shape specimens, the materials were characterized by mechanical testing (tensile mode), scanning electron microscopy, and theoretical simulations by finite elements analysis (FEA). In terms of mechanical properties, only the elastic moduli (Et) exhibited results ranging from 37% to 170%, depending on the reinforcement composition. Conversely, strengths at break, under both tensile and bending tests, tended to decrease, indicating poor affinity between the components. Due to the mechanical treatment applied on the fiber, DFBF emerged as the most promising filler, with mechanical properties closest to those of neat PHB. DFBF-based composites were subsequently produced through process intensification using a twin-screw extruder, and molded into flowerpots. Mechanical results showed almost identical properties between the discontinuous and intensification processes. The suitability of the material for agriculture flowerpots was demonstrated through finite analysis simulation (FEA), which revealed that the maximum von Mises stresses (5.38 × 105 N/m2) and deformations (0.048 mm) were well below the limits of the composite materials.
RESUMO
Since 2010, huge quantities of Sargassum spp. algae have been proliferating in the Atlantic Ocean and stranding on Caribbean beaches, causing major economic, environmental, and health problems. In this study, an innovative high-density binderless particleboard was developed using uniaxial thermo-compression coupled with a cooling system. The raw material consisted of ground Sargassum seaweeds pre-treated by twin-screw extrusion with water to remove sea salt. The raw material and the particleboards were produced by using various analytical techniques such as Dynamic Vapor Sorption (DVS), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), or Thermogravimetric Analysis (TGA). The experimental conditions for thermo-compression (temperature, pressure, time) were evaluated. The best thermo-compression conditions tested were 200 °C, 40 MPa pressure for 7.5 min. This resulted in a particleboard with high density (up to 1.63 ± 0.02 g/cm3) and high flexural strength/modulus (up to 32.3 ± 1.8 MPa/6.8 ± 0.2 GPa, respectively), but a low water contact angle of 38.9° ± 3.5°. Thermal analyses revealed the effect of alginates on the mechanical properties of particleboards. This work opens the door to a new way of adding value to Sargassum seaweed, using the whole algae with minimal pre-treatment.
RESUMO
Several vertebrates choose their mate according to genetic heterozygosity and relatedness, and use odour cues to assess their conspecifics' genetic make-up. In birds, although several species (including the black-legged kittiwake) exhibit non-random mating according to genetic traits, the cues used to assess genetic characteristics remain unknown. The importance of olfaction in birds' social behaviour is gaining attention among researchers, and it has been suggested that, as in other vertebrates, bird body scent may convey information about genetic traits. Here, we combined gas chromatography data and genetic analyses at microsatellite loci to test whether semiochemical messages in preen secretion of kittiwakes carried information about genetic heterozygosity and relatedness. Semiochemical profile was correlated with heterozygosity in males and females, while semiochemical distance was correlated with genetic distance only in male-male dyads. Our study is the first to demonstrate a link between odour and genetics in birds, which sets the stage for the existence of sophisticated odour-based mechanisms of mate choice also in birds.
Assuntos
Charadriiformes/genética , Variação Genética , Odorantes , Feromônios/genética , Animais , Charadriiformes/metabolismo , Feminino , Asseio Animal , Masculino , Feromônios/química , Comportamento Sexual Animal , Olfato , Comportamento SocialRESUMO
Twenty-four strains of Lactococcus lactis isolated from raw goat milk collected in the Rocamadour PDO area were analysed by MLST typing and phenotypic characterisation. The strains were combined to design an indigenous starter for the production of Rocamadour PDO cheese. The strains were divided into three classes based on their technological properties: acidifying and proteolytic strains in class I (12/24 strains), slightly acidifying and non-proteolytic strains in class II (2/24 strains), and non-acidifying and non-proteolytic strains in class III (10/24 strains). Interestingly, all but three strains (21/24) produced diacetyl/acetoin despite not having citrate metabolism genes, as would classically be expected for the production of these aroma compounds. Three strains (EIP07A, EIP13D, and EIP20B) were selected for the indigenous starter based on the following inclusion/exclusion criteria: (i) no negative interactions between included strains, (ii) ability to metabolize lactose and at least one strain with the prtP gene and/or capable of producing diacetyl/acetoin, and (iii) selected strains derived from different farms to maximise genetic and phenotypic diversity. Despite consisting exclusively of L. lactis strains, the designed indigenous starter allowed reproducible cheese production with performances similar to those obtained with an industrial starter and with the sensory qualities expected of Rocamadour PDO cheese.
Assuntos
Queijo , Lactococcus lactis , Acetoína/metabolismo , Animais , Diacetil/metabolismo , Cabras , Lactococcus lactis/metabolismo , Leite , Tipagem de Sequências MultilocusRESUMO
INTRODUCTION: An association between HIV infection and chronic obstructive pulmonary disease (COPD) has been observed in several studies. OBJECTIVE AND METHODS: we conducted a review of the literature linking HIV infection to COPD, focusing on clinical and epidemiological data published before and during widespread highly active antiretroviral therapy (HAART). RESULTS: Interactions between HIV infection and COPD appear to be influenced by multiple factors. In particular, the bronchopulmonary tract can be damaged by HIV infection, the immunodeficiency it induces, and the resulting increase in the risk of pulmonary infections. In addition, the prevalence of smoking and intravenous drug use is higher in HIV-infected populations, also increasing the risk of COPD. Before the advent of HAART, respiratory tract infections probably played a major role. Since the late 1990s and the widespread use of HAART, the frequency of opportunistic infections has fallen but new complications have emerged as life expectancy has increased. CONCLUSION: given the high prevalence of smoking among HIV-infected patients, COPD may contribute significantly to morbidity and mortality in this setting.
Assuntos
Infecções por HIV/epidemiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Fatores Etários , Terapia Antirretroviral de Alta Atividade , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Humanos , Prevalência , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Medição de Risco , Fatores de Risco , Fumar/epidemiologiaRESUMO
The importance of olfaction in birds' social behavior has long been denied. Avian chemical signaling has thus been relatively unexplored. The black-legged kittiwake provides a particularly appropriate model for investigating this topic. Kittiwakes preferentially mate with genetically dissimilar individuals, but the cues used to assess genetic characteristics remain unknown. As in other vertebrates, their body odors may carry individual and sexual signatures thus potentially reliably signaling individual genetic makeup. Here, we test whether body odors in preen gland secretion and preen down feathers in kittiwakes may provide a sex and an individual signature. Using gas chromatography and mass spectrometry, we found that male and female odors differ quantitatively, suggesting that scent may be one of the multiple cues used by birds to discriminate between sexes. We further detected an individual signature in the volatile and nonvolatile fractions of preen secretion and preen down feathers. These results suggest that kittiwake body odor may function as a signal associated with mate recognition. It further suggests that preen odor might broadcast the genetic makeup of individuals, and could be used in mate choice to assess the genetic compatibility of potential mates.
Assuntos
Charadriiformes/fisiologia , Plumas/química , Feromônios/análise , Comportamento Sexual Animal , Animais , Feminino , Asseio Animal , Masculino , Glândulas Odoríferas/química , Glândulas Odoríferas/metabolismo , Caracteres SexuaisRESUMO
Carbohydrates are the most recurrent materials employed for active components encapsulation using twin-screw extrusion. However, the influence of process parameters on the properties of the final product remains a challenge. In this paper, special attention was given to the incorporation of a hydrophobic model compound (MCT-oil), in a maltodextrin matrix with a compatibilizing biopolymer. The effects of the extrusion parameters, as well as the influence of different formulations were analyzed. The mild extrusion conditions allowed obtaining blends with acceptable texture and viscosity to enhance the dispersion of the active compound. The encapsulation systems obtained were in a glassy state at room temperature and they remained stable at 60 % RH for a long time. Satisfactory incorporation rates of MCT-oil were found reaching encapsulation efficiencies up to 90 %. These results showed that the chosen compatibilizing agent enhanced the dispersion and stabilization of the MCT-oil within the matrix and significantly improved encapsulation.
Assuntos
Suplementos Nutricionais , Polissacarídeos , Biopolímeros , Composição de MedicamentosRESUMO
PURPOSE: The limited knowledge on the molecular profile of patients with BRAF-mutant non-small cell lung cancer (NSCLC) who progress under BRAF-targeted therapies (BRAF-TT) has hampered the development of subsequent therapeutic strategies for these patients. Here, we evaluated the clinical utility of circulating tumor DNA (ctDNA)-targeted sequencing to identify canonical BRAF mutations and genomic alterations potentially related to resistance to BRAF-TT, in a large cohort of patients with BRAF-mutant NSCLC. EXPERIMENTAL DESIGN: This was a prospective study of 78 patients with advanced BRAF-mutant NSCLC, enrolled in 27 centers across France. Blood samples (n = 208) were collected from BRAF-TT-naïve patients (n = 47), patients nonprogressive under treatment (n = 115), or patients at disease progression (PD) to BRAF-TT (24/46 on BRAF monotherapy and 22/46 on BRAF/MEK combination therapy). ctDNA sequencing was performed using InVisionFirst-Lung. In silico structural modeling was used to predict the potential functional effect of the alterations found in ctDNA. RESULTS: BRAFV600E ctDNA was detected in 74% of BRAF-TT-naïve patients, where alterations in genes related with the MAPK and PI3K pathways, signal transducers, and protein kinases were identified in 29% of the samples. ctDNA positivity at the first radiographic evaluation under treatment, as well as BRAF-mutant ctDNA positivity at PD were associated with poor survival. Potential drivers of resistance to either BRAF-TT monotherapy or BRAF/MEK combination were identified in 46% of patients and these included activating mutations in effectors of the MAPK and PI3K pathways, as well as alterations in U2AF1, IDH1, and CTNNB1. CONCLUSIONS: ctDNA sequencing is clinically relevant for the detection of BRAF-activating mutations and the identification of alterations potentially related to resistance to BRAF-TT in BRAF-mutant NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , DNA Tumoral Circulante/genética , Resistencia a Medicamentos Antineoplásicos , Terapia de Alvo Molecular/métodos , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/secundário , DNA Tumoral Circulante/análise , Seguimentos , Genômica/métodos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Prognóstico , Estudos Prospectivos , Taxa de SobrevidaRESUMO
PURPOSE: To measure phrenic nerve conduction velocity in the neck in humans. SCOPE: We studied 15 healthy subjects (9 men, 32.4+/-6.7). We performed bipolar electrical phrenic stimulation in the neck, from a distal and a proximal stimulation site, and recorded diaphragm electromyographic responses on the surface of the chest. The ratio of the between-site distance to the latency difference provided phrenic velocities. Ulnar motor velocity was assessed similarly. In addition, five homogeneous patients with Charcot-Marie-Tooth disease type 1A (CMT1A) were studied for validation purposes. We obtained diaphragmatic responses from the two stimulation sites in all cases. The distal latencies (anterior axillary line recording) were 6.51+/-0.63ms (right) and 6.13+/-0.64ms (left). The minimal between site distance was 39mm. Phrenic motor velocity was 55.2+/-6.3ms(-1) (right) and 56.3+/-7.2ms(-1) (left). In CMT1A, phrenic velocities were 17.1+/-8.1ms(-1) (from 7 to 32ms(-1)) and were similar to ulnar and median velocities. CONCLUSIONS: Phrenic nerve velocities can be estimated in humans and compare with upper limb motor conduction velocities. This should refine the investigation of phrenic function in peripheral neuropathies.
Assuntos
Condução Nervosa/fisiologia , Nervo Frênico/fisiologia , Adulto , Doença de Charcot-Marie-Tooth/fisiopatologia , Diafragma/inervação , Estimulação Elétrica , Eletromiografia , Feminino , Humanos , Masculino , Nervo Mediano/fisiologia , Nervo Mediano/fisiopatologia , Pessoa de Meia-Idade , Pescoço , Nervo Frênico/fisiopatologia , Tempo de Reação , Nervo Ulnar/fisiologia , Nervo Ulnar/fisiopatologiaRESUMO
The air quality over the Toulouse urban area (France) is recorded daily by the regional "Midi-Pyrénées" atmospheric pollution measurements network (ORAMIP). Relevant data is collected from about 100 analysers spread over more than thirty stations. The regulations covering major indicators of atmospheric pollution (ozone, nitrogen dioxide, sulphur dioxide) have been updated in recent years to include additional compounds like polycyclic aromatic hydrocarbons (PAHs). The ORAMIP, in partnership with the ENSIACET has undertaken background PAH average concentration measurements over the urban agglomeration of Toulouse during spring 2006 for various types of sites (traffic, urban, industrial). The sampling was performed using a low volume air sampler equipped with quartz fiber filters and polyurethane foams For the two urban sites, total atmospheric concentrations between 12 and 20 ng/m(3) have been obtained, whereas for the industrial site the values averaged 22 ng/m(3). In addition, and regardless of site, the average concentrations of benzo[a]pyrene, at present the only regulated PAH, were always less than the 1 ng/m(3) limit.
Assuntos
Poluentes Atmosféricos/análise , Cidades , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Atmosfera , Exposição Ambiental , França , Humanos , Exposição Ocupacional , Análise de Componente PrincipalRESUMO
Currently essential oil from black currant ( Ribes nigrum L.) buds is mainly used as a valuable perfumery ingredient. This study reports more comprehensive characterization of dormant buds of various black currant ( Ribes nigrum L.) cultivars which are grown in Northern European countries. Essential oils were isolated from the buds by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), GC-flame ionization detection (GC-FID), and GC--olfactometry (GC-O). The most abundant compounds in black currant bud essential oil were sabinene, delta-3-carene, and terpinolene. The most frequent descriptors of the essential oil components assessed by GC-O were "woody", "terpene", "fruity", "sweet", "citrus", "herbaceous", "pine", "green", "oily", "herbal", and "musty". The residues obtained after hydrodistillation were separated into liquid and solid fractions. The solid fraction was dried and extracted with acetone (AE), while the liquid fraction (water extract) was divided in two parts, one of which was spray-dried (SDWF extracts) and the other freeze-dried (FDWF extract). In addition, a portion of whole frozen buds was extracted with methanol (ME). The radical scavenging capacity (RSC) of black currant bud extracts varied in a wide range; in the DPPH * reaction system FDWF at the applied concentration scavenged 43-79%; SDWF, 54-80%; AE, 16-36%; ME, 42-60% of radicals; while in the ABTS *+ reaction system the RSC was 39-72, 38-53, 1-5, and 30-49%, respectively. The total amount of phenolic compounds expressed in gallic acid equivalents in FDWF varied in the range of 132-192 mg/g; in SDWF, 140-209 mg/g; in AE, 49-107 mg/g; and in ME extracts, 111-180 mg/g.
Assuntos
Antioxidantes/farmacologia , Flores/química , Odorantes/análise , Óleos Voláteis/química , Ribes/química , Vapor/análise , Monoterpenos Bicíclicos , Cromatografia Gasosa , Monoterpenos Cicloexânicos , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/análise , Extratos Vegetais/farmacologia , Olfato , Terpenos/análise , VolatilizaçãoRESUMO
Industrial gelatins have different physicochemical properties that mainly depend of the raw materials origin and the extraction conditions. These properties are closely related to the molar mass distribution of these gelatins. Several methods exist to characterize molar mass distribution of polymer, including the Asymmetrical Flow Field Flow Fractionation method. The goal of this study is to analyze the relationship between physicochemical properties and the gelatins molar mass distribution obtained by Asymmetrical Flow Field Flow Fractionation. In this study, 49 gelatins samples extracted from pig skin are characterized in terms of gel strength and viscosity and their molar mass distribution are analyzed by Asymmetrical Flow Field Flow Fractionation coupled to an Ultraviolet and Multi Angle Light Scattering detector. This analytical method is an interesting tool for studying, simultaneously, the primary chains and the high-molar-mass fraction corresponding to the polymer chains. Correlation analysis between molar mass distribution data from the different fractions highlights the importance of high molar mass polymer chains to explain the gel strength and viscosity of gelatins. These results are confirmed by an additional chemometric approach based on the UV absorbance of gelatin fractograms to predict gel strength (r2Cal = 0.85) and viscosity (r2Cal = 0.79).
Assuntos
Fracionamento por Campo e Fluxo , Gelatina/química , Polímeros/química , Gelatina/isolamento & purificação , Luz , Peso Molecular , Polímeros/isolamento & purificação , Espalhamento de Radiação , ViscosidadeRESUMO
BACKGROUND: Inspiratory occlusion evoked cortical potentials (the respiratory related-evoked potentials, RREPs) bear witness of the processing of changes in respiratory mechanics by the brain. Their impairment in children having suffered near-fatal asthma supports the hypothesis that relates asthma severity with the ability of the patients to perceive respiratory changes. It is not known whether or not chronic respiratory defects are associated with an alteration in brain processing of inspiratory loads. The aim of the present study was to compare the presence, the latencies and the amplitudes of the P1, N1, P2, and N2 components of the RREPs in children with chronic lung or neuromuscular disease. METHODS: RREPs were recorded in patients with stable asthma (n = 21), cystic fibrosis (n = 32), and neuromuscular disease (n = 16) and in healthy controls (n = 11). RESULTS: The 4 RREP components were significantly less frequently observed in the 3 groups of patients than in the controls. Within the patient groups, the N1 and the P2 components were significantly less frequently observed in the patients with asthma (16/21 for both components) and cystic fibrosis (20/32 and 14/32) than in the patients with neuromuscular disease (15/16 and 16/16). When present, the latencies and amplitudes of the 4 components were similar in the patients and controls. CONCLUSION: Chronic ventilatory defects in children are associated with an impaired cortical processing of afferent respiratory signals.
Assuntos
Córtex Cerebral/fisiologia , Potenciais Evocados/fisiologia , Inalação/fisiologia , Insuficiência Respiratória/fisiopatologia , Adolescente , Criança , Doença Crônica , Feminino , Humanos , MasculinoRESUMO
The sample matrix can enhance the gas chromatography signal of pesticide residues relative to that obtained with the same concentration of pesticide in solvent. This paper is related to negative matrix effects observed in coupled gas chromatography-mass spectrometry ion trap (GC/MS2) quantification of pesticides in concentrated extracts of apple peel prepared by the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) method. It is focused on the pesticides most frequently used on the apple varieties studied, throughout the crop cycle, right up to harvest, to combat pests and diseases and to improve fruit storage properties. Extracts from the fleshy receptacle (flesh), the epiderm (peel) and fruit of three apple varieties were studied by high-performance thin-layer chromatography hyphenated with UV-vis light detection (HPTLC/UV visible). The peel extracts had high concentrations of triterpenic acids (oleanolic and ursolic acids), reaching 25mgkg-1, whereas these compounds were not detected in the flesh extracts (<0.05mgkg-1). A significant relationship has been found between the levels of these molecules and negative matrix effects in GC/MS2. The differences in the behavior of pesticides with respect to matrix effects can be accounted for by the physicochemical characteristics of the molecules (lone pairs, labile hydrogen, conjugation). The HPTLC/UV visible method developed here for the characterization of QuEChERS extracts acts as a complementary clean-up method, aimed to decrease the negative matrix effects of such extracts.
Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Malus/química , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Terpenos/análise , Cromatografia em Camada Fina , Densitometria , Frutas/química , Modelos Lineares , Polifenóis/análise , Solventes/análise , Espectrofotometria UltravioletaRESUMO
Background: This study aimed to examine the composition of essential oil (EO) of A. millefolium aerial parts wild plant grown in France and evaluate its antioxidant, antibacterial, and antifungal activities. Methods: GC-MS was used to identify the chemical composition of EO. Antioxidant activity (AA) of EO was evaluated by Oxipres method. Antimicrobial activity of EO was evaluated by Agar-well diffusion and a broth microdilution assay. Results: Forty-three volatile compounds were identified. Major compounds were camphor (12.8%), germacrene-D (12%), (E)-nerolidol (7.3%), sabinene (6.7%), (E)-p-mentha-2,8-dien-1-ol (4.5%), and 1,8-cineole (4%). EO shows strong AA against Sunflower oil oxidation. Additionally, an inhibitory effect against microbial organisms (bacteria and fungi) was found. Conclusion: The EO composition of A. millefolium chemotype located in France was studied. The EO of the A. millefolium wild plant grown in France is quite an effective antioxidant in sunflower oil oxidation; it also possesses inhibitory effects against famous bacteria and fungi.