Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 221
Filtrar
1.
Dig Liver Dis ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38719628

RESUMO

BACKGROUND AND AIMS: Oxaliplatin (OX) has been described as a potential etiologic agent for porto-sinusoidal vascular disorder (PSVD). Our aim was to describe the natural history of PSVD due to OX in colon cancer (CRC) and identify risk factors for its development. METHODS: We made a multicenter retrospective case-control (ratio 1:3) study with patients diagnosed of PSVD-OX. Baseline data, end of treatment, years of follow-up and diagnosis of PSVD were collected and compared to controls (without PSVD). Besides, 16 different SNPs were selected from bibliography and analyzed by genotyping in the case group to identify potential genetic risk factors. RESULTS: 41 cases were identified, with a median time to PSVD diagnosis after the end of OX of 34 months. Spleen diameter was the strongest predictor of PSVD during treatment (OR 43.94 (14.48-133.336); p < 0.0001). Additionally, thrombocytopenia (<150 × 10^9) at one year was a significant disease risk marker (OR 9.35; 95% CI: 3.71-23.58; p = 0.001). We could not establish any significant association between the selected SNPs and PSVD diagnosis. CONCLUSION: The increase of spleen diameter is the strongest predictor of PSVD in patients treated with OX for CRC. These patients could be candidates for a specific follow-up of portal hypertension-related complications.

2.
Oecologia ; 203(3-4): 349-360, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37951847

RESUMO

Appreciation for the role of cryptofauna in ecological systems has increased dramatically over the past decade. The impacts blood-feeding arthropods, such as ticks and mosquitos, have on terrestrial communities are the subject of hundreds of papers annually. However, blood-feeding arthropods have been largely ignored in marine environments. Gnathiid isopods, often referred to as "ticks of the sea", are temporary external parasites of fishes. They are found in all marine environments and have many consequential impacts on host fitness. Because they are highly mobile and only associated with their hosts while obtaining a blood meal, their broader trophic connections are difficult to discern. Conventional methods rely heavily on detecting gnathiids on wild-caught fishes. However, this approach typically yields few gnathiids and does not account for hosts that avoid capture. To overcome this limitation, we sequenced blood meals of free-living gnathiids collected in light traps to assess the host range and community-dependent exploitation of Caribbean gnathiid isopods. Using fish-specific COI (cox1) primers, sequencing individual blood meals from 1060 gnathiids resulted in the identification of 70 host fish species from 27 families. Comparisons of fish assemblages to blood meal identification frequencies at four collection sites indicated that fishes within the families Haemulidae (grunts) and Lutjanidae (snappers) were exploited more frequently than expected based on their biomass, and Labrid parrotfishes were exploited less frequently than expected. The broad host range along with the biased exploitation of diel-migratory species has important implications for the role gnathiid isopods play in Caribbean coral reef communities.


Assuntos
Doenças dos Peixes , Isópodes , Humanos , Animais , Recifes de Corais , Especificidade de Hospedeiro , Doenças dos Peixes/parasitologia , Peixes , Refeições , Isópodes/parasitologia
3.
Phys Med Biol ; 67(24)2022 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-36541550

RESUMO

Objective.Magnetic Particle Imaging (MPI) promises to enhance diagnostic capabilities of the existing clinical imaging modalities. Traditional MPI scanners utilize cylindrical bore geometry that prevents scaling up the MPI to accommodate full human subject. Single-sided geometry, on the other hand, has all the hardware located on one side providing an unrestricted imaging volume.Approach.Our single-sided MPI device utilizes a field-free line topology with a single drive coil and a surface receive coil, which is used to detect the nanoparticles. Unlike closed bore systems, single-sided devices cannot adapt well established solenoid gradiometer receive coil, which result in impinging potential sensitivity gain.Main results.In this work we study multiple receive coil configurations with compensation for the purpose of removing feedthrough, whilst preserving the superparamagnetic iron oxide nanoparticle signal. Moreover, we present a compensated surface receive coil design that provides highest sensitivity in the single-sided geometry and demonstrate a new detection limit in a single-sided scanner of 100 ng of iron. In addition, we demonstrate 1D imaging of a sample without use of receive filter recovering signal at fundamental harmonic.Significance.These advancements in the receive chain are crucial for developing a practical MPI scanner with a single-sided geometry.


Assuntos
Nanopartículas de Magnetita , Humanos , Limite de Detecção , Diagnóstico por Imagem/métodos , Nanopartículas Magnéticas de Óxido de Ferro
4.
Clin Gastroenterol Hepatol ; 20(10): 2276-2286.e6, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34688952

RESUMO

BACKGROUND & AIMS: Portal hypertension is the strongest predictor of hepatic decompensation and death in patients with cirrhosis. However, its discriminatory accuracy in patients with nonalcoholic fatty liver disease (NAFLD) has been challenged because hepatic vein catheterization may not reflect the real portal vein pressure as accurately as in patients with other etiologies. We aimed to evaluate the relationship between hepatic venous pressure gradient (HVPG) and presence of portal hypertension-related decompensation in patients with advanced NAFLD (aNAFLD). METHODS: Multicenter cross-sectional study included 548 patients with aNAFLD and 444 with advanced RNA-positive hepatitis C (aHCV) who had detailed portal hypertension evaluation (HVPG measurement, gastroscopy, and abdominal imaging). We examined the relationship between etiology, HVPG, and decompensation by logistic regression models. We also compared the proportions of compensated/decompensated patients at different HVPG levels. RESULTS: Both cohorts, aNAFLD and aHVC, had similar baseline age, gender, Child-Pugh score, and Model for End-Stage Liver Disease score. Median HVPG was lower in the aNAFLD cohort (13 vs 15 mmHg) despite similar liver function and higher rates of decompensation in aNAFLD group (32% vs 25%; P = .019) than in the aHCV group. For any of the HVPG cutoff analyzed (<10, 10-12, or 12 mmHg) the prevalence of decompensation was higher in the aNAFLD group than in the aHCV group. CONCLUSIONS: Patients with aNAFLD have higher prevalence of portal hypertension-related decompensation at any value of HVPG as compared with aHCV patients. Longitudinal studies aiming to identify HVPG thresholds able to predict decompensation and long-term outcomes in aNAFLD population are strongly needed.


Assuntos
Doença Hepática Terminal , Hepatite C , Hipertensão Portal , Hepatopatia Gordurosa não Alcoólica , Estudos Transversais , Doença Hepática Terminal/complicações , Hepatite C/complicações , Humanos , Hipertensão Portal/etiologia , Cirrose Hepática/complicações , Hepatopatia Gordurosa não Alcoólica/complicações , Pressão na Veia Porta , RNA , Índice de Gravidade de Doença
5.
Sci Rep ; 10(1): 8649, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32457295

RESUMO

Severe disturbances can substantially alter eco-evolutionary processes and dynamics. While the impacts of catastrophic events on the biophysical attributes of communities are sometimes assessed, their effects on the genetic patterns of species remain poorly understood. To characterize how severe disturbances impact species at the molecular level, we examined the effects of the most energetic North Atlantic hurricane season in 50 years on the genetic diversity and structure of a dispersal-limited isopod, Gnathia marleyi. We sequenced a portion of the cytochrome oxidase I gene for 432 gnathiids, collected from six localities, ranging from western Puerto Rico to St John, US Virgin Islands. Importantly, multiple years of pre-hurricane sample collection allowed us to characterize temporal genetic patterns under undisturbed conditions and detect the changes subsequent to the 2017 hurricanes. Our results revealed no change to genetic diversity or structure for the years prior to the 2017 hurricanes, with genetic structure occurring at the local and regional levels, with three main clusters corresponding to Southwest Puerto Rico, East Puerto Rico, and the US Virgin Islands. However, directly following the 2017 hurricanes, genetic diversity increased at five of the six sampled localities. Additionally, we found a clear homogenizing effect prompted by increased shared genetic diversity among geographically distant regions and sites that resulted in substantially decreased among-region and among-site differentiation. Our work shows that severe disturbances caused by major tropical hurricanes facilitate gene-flow and increase overall genetic diversity and population admixture of dispersal limited coral reef species, potentially impacting the ecology and evolution of a key regional endemic.


Assuntos
Tempestades Ciclônicas , Fenômenos Ecológicos e Ambientais/fisiologia , Fluxo Gênico/genética , Variação Genética/genética , Isópodes/genética , Animais , Oceano Atlântico , Sequência de Bases , Recifes de Corais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Dinâmica Populacional , Análise de Sequência de DNA
6.
Parasitol Res ; 119(6): 1975-1980, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32333110

RESUMO

Gnathiid isopods are marine ectoparasites that feed on the blood of fishes that have been implicated as vectors of blood parasites, with transmission possibly occurring through biting during their parasitic life-stages, or through ingestion by fishes. However, evidence for their role as vectors is limited, reflecting the small number of research groups working on them. Here, we used a molecular barcode approach to identify fish hosts and apicomplexan parasites in free-living gnathiids from the eastern Caribbean Sea, with the goal of further evaluating their potential role as reservoirs and/or vectors for these parasites. Apicomplexa were only identified in 8% of the Gnathia analyzed, and in four cases we could identify both Apicomplexa and fish host DNA. The results further suggest that Gnathia spp. in this region may serve as reservoirs for Apicomplexa, but whether they are vectors for this parasite remains uncertain.


Assuntos
Apicomplexa/isolamento & purificação , Doenças dos Peixes/parasitologia , Isópodes/parasitologia , Animais , Região do Caribe , Recifes de Corais , Código de Barras de DNA Taxonômico , Vetores de Doenças , Peixes/parasitologia
7.
Sci Total Environ ; 687: 1034-1045, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31412441

RESUMO

Dune ecosystems play a key role in coastal dynamics, so it is essential to measure their movements with high precision and monitor their changes over time. It is crucial to have a system that allows us to know the natural and anthropic impacts affecting these ecosystems. The aim of this study is to ascertain the historical evolution of the dune system of Guardamar del Segura (Spain) and its relationship with coastal erosion. Likewise, it is also intended to assess the state of the foredune restoration works carried out in 2011. To this end, a comparison of existing cartographic data has been undertaken by using geospatial analysis techniques through Geographic Information Systems (GIS). As a novelty, a low takeoff weight UAV (Unmanned Aerial Vehicle) has been used to produce a high-precision 3D model from two-dimensional images using photogrammetric techniques, such as Structure from Motion (SfM). This technique made it possible to obtain a digital terrain model of high density and precision (30 pt/m2 and RMSE Z of 0.173 m). The results show a constant erosion of both the beach and the foredune, with an overall loss of 143,561 m3 of material in the period analyzed (2001-2017). The anthropogenic restoration actions executed within this period have not been effective. In fact, erosion has increased in the period 2016-2017, with a significant reduction in the beach width and sea waves directly affecting the foredune. The main conclusion is that the combined use of UAV and SfM techniques is an excellent procedure to periodically supervise dune ecosystems with high precision and significant time and cost savings.

8.
Sci Total Environ ; 660: 1256-1263, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-30743920

RESUMO

Coastal erosion and lack of sediment supply are a serious global problem. It is therefore necessary to determine the depth of closure (DoC) of a beach-key parameter in the calculation of the sand volume and the location of the beach protection elements-in a precise way. For this reason, this work generates a numerical model based on Galerkin's formulation of finite elements that provides sufficient precision for the determination of DoC with a minimum investment. Thus, after the generation of three models in which the difference was the dependent variables, the least complex has been chosen. It is composed of the variables: median sediment size, wave height and period associated with the mean flow, as well as the angle that the mean flow forms with respect to the studied profile in absolute value (α). The selected model has been compared with the most commonly used models currently in use, having an average absolute error of 0.36 m and an average MAPE of <7.5%, which represents an improvement of >70% over current models. In addition, it presents a high stability, since after the random disturbance of all the input variables (up to 5%), the model error remains stable, increasing the MAPE by a maximum of 7.4% and the average absolute error by 0.15 m. Therefore, it is possible to use the model to infer the DoC in other study areas where the values of the variables are similar to those studied here, although the selected method can be extrapolated to other parts of the world.

9.
Sci Total Environ ; 634: 739-748, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29649718

RESUMO

Storms can alter the beach shape, relocating large volumes of sediments and generating drastic changes in the coastline. In the last 60years, beaches shoreline behaviour has been different even though the energy of the waves was similar. Therefore, it is necessary to understand the factors that affect the sandy coasts for better future management. In this research, two beaches, with different erosion rate, located in the southeast of Spain (separated by only 40km of distance) have been studied. The beaches: i) have similar orientations, ii) are open to waves with similar sand lengths of 9.8km and 6.6km, and iii) have similar median sediment size (D50). For its study, shoreline evolution has been analysed from 1956 to 2017. From the results obtained, it can be seen that: i) Between 1992 and 2017, San Juan just lost 3% of its surface, while in the previous period (1956-1990) it was 50%, and ii) Guardamar surface lost in 1992-2017 was 18%, and in the previous period it was 14%. For the analysis of the agents involved in both beaches, cross-shore profiles (volume), marine climate, biocenosis and sedimentology studies were carried out. The results showed that the energy on both beaches was very similar. The biocenosis had not changed and, however, the morphology of Guardamar seabed had increased to 1m deep in some places, which had caused part of the beach berm erosion. Furthermore, important differences were found from the sedimentological study, concluding that the content of calcites and the degree of homogeneity of the particles are the real factors that caused these two beaches to behave differently against erosion.

10.
Sci Total Environ ; 628-629: 64-73, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29428861

RESUMO

Actions taken to prevent or reduce coastal erosion often do not have the desired effect, leading to major problems instead of solving the original one. This research focuses on why a nourished beach- with borrowed sand and 0.05% of particles <0.063 mm- causes the presence of suspended particles that are observed by beach users as turbidity. This means that the colour of the water was not its characteristic blue, even with calm wave conditions. This research involved a shoreline evolution analysis and a sedimentological study of the sand from 1977 to 2017. The results show that the turbidity episodes that occurred after the beach fill of May 2017 do not coincide with major storms that affected the beach. Furthermore, prior to this beach nourishment, even after the most important storms turbidity was not so pronounced. However, when the pre-nourishment and post-nourishment sediment are compared and analysed in detail, by studying the microstructure and morphology of the sand particles, their composition and morphology were observed to be completely different. These differences are also reflected in the accelerated particle weathering test, with the post-nourishment particles showing greater dissolution of carbonates. From its mineralogy, the post-nourishment material presents a smaller proportion of quartz in its composition and a significant amount of particles (9.6%) formed by clusters of Calcium and Silicon. The separation of this mineralogical composition produced by waves explains the formation of particles measuring <0.063 mm, a fact that has also been confirmed by the accelerated particle weathering test. This is, therefore, the cause of turbidity in the swash zone of the beach.

11.
Sci Total Environ ; 626: 87-95, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29335177

RESUMO

Coastal erosion is a worldwide problem, so accurate knowledge of the factors involved in the shoreline evolution is of great importance. This study analysed three gravel beaches that were nourished with sand from the same source. However, the evolution of their shoreline was different in each case. For its analysis, different factors were studied such as the shoreline and cross-shore profile evolution, the maritime climate, sedimentology and mineralogy. From the results, it should be noted that Centro beach is the most stable with a loss of surface after the first regeneration of 12.8%, while Carrer de mar is the most instable with a loss of 20.9%. The Posidonia oceanica meadow is one of the factors that make Centro beach the most stable despite being the one that receives the most wave energy. Another factor is its mineralogy and more specifically the composition of the particles that form the sample. Thus, it is observed how the cracking or the formation of particles by different minerals with a fragile union, are factors that make the beaches behave differently against erosion. For this reason, it is concluded that in order for the shoreline to be as stable as possible over time, a previous study of the sediment to be used for nourishment is necessary, as well as its possible effect on the ecosystem, since the future shoreline evolution will depend on it.

12.
Sci Total Environ ; 601-602: 1364-1377, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28605855

RESUMO

There are many activities and uses in the coastal environment, which has historically attracted the humans. This attraction has led to many anthropic actions that have generated imbalances, more important as the human pressure increases. This research focuses on the effects of these pressures along of 11km of the coastline of Guardamar del Segura, a high-value environmental area where is the Segura River mouth and one of the last dune systems of the southeast of Spain. The historic evolution of the shoreline position has been analysed using 60years of aerial images from 1950s to 2014, the seabed depth changes, the maritime climate, the distribution of the sediment grain size and the anthropic actions such as urban development or the channelling of the river. All data were integrated and processed using a Geographic Information System (GIS). The results show that the lack of sediment supply by Segura River and the cut-off in the longshore transport due to the breakwaters and others anthropic actions has led into an increase in the beaches erosion rates, with a loss of >3.2millionm3 of sand in the last 58years (≈55,200m3/year). The conclusions of this research could be useful to the coastal managers at the moment of making the decisions of action and/or conservation on a coastal system to achieve positive results in the medium and long term.

15.
Aliment Pharmacol Ther ; 43(11): 1222-31, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27061098

RESUMO

BACKGROUND: Noninvasive identification of significant portal hypertension in patients with cirrhosis is needed in hepatology practice. AIM: To investigate whether the combination of sCD163 as a hepatic inflammation marker and the fibrosis markers of the Enhanced Liver Fibrosis score (ELF) can predict portal hypertension in patients with cirrhosis. METHODS: We measured sCD163 and the ELF components (hyaluronic acid, tissue inhibitor of metalloproteinase-1 and procollagen-III aminopeptide) in two separate cohorts of cirrhosis patients that underwent hepatic vein catheterisation. To test the predictive accuracy we developed a CD163-fibrosis portal hypertension score in an estimation cohort (n = 80) and validated the score in an independent cohort (n = 80). A HVPG ≥10 mmHg was considered clinically significant. RESULTS: Both sCD163 and the ELF components increased in a stepwise manner with the patients' Child-Pugh score (P < 0.001, all), and also with increasing HVPG (P < 0.001). receiver operator characteristics (ROC) analyses showed that each one of the individual components predicted a HVPG >10 mmHg with AUROC's of approximately 0.80. The combined score optimised by logistic regression analyses improved the AUROC to 0.91 in the estimation cohort and 0.90 in the validation cohort. Furthermore, a high value of the combined score was associated with a high short-term mortality. CONCLUSIONS: The combination of the macrophage activation marker sCD163 and the fibrosis markers predicted significant portal hypertension in patients with cirrhosis. This score may prove useful for screening purposes and highlights the importance of both the inflammatory and the fibrotic components of cirrhotic portal hypertension.


Assuntos
Hipertensão Portal/fisiopatologia , Cirrose Hepática/fisiopatologia , Ativação de Macrófagos , Idoso , Biomarcadores , Estudos Transversais , Feminino , Veias Hepáticas/fisiopatologia , Humanos , Hipertensão Portal/complicações , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Curva ROC , Inibidor Tecidual de Metaloproteinase-1/metabolismo
16.
Sci Total Environ ; 559: 242-255, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27065444

RESUMO

Coastal areas have been historically characterized as being a source of wealth. Nowadays, beaches have become more relevant as a place for rest and leisure. This had led to a very high population pressure due to rapid urbanisation processes. The impacts associated with coastal tourism, demand the development of anthropic actions to protect the shoreline. This paper has studied the impacts of these actions on the Marineta Cassiana beach, in Denia, Spain. This particular Mediterranean beach has traditionally suffered a major shoreline regression, and the beach nourishments carried out in the 1980s would not have achieved the reliability desired. This research has analysed the historic evolution of the beach and its environment for a period of 65years (1950-2015). A Geographic Information System (GIS) has been used to integrate and perform a spatial analysis of urban development, soil erosion, stream flow, swell, longshore transport, submerged vegetation species and shoreline evolution. The results show how the anthropic actions have affected the shoreline. After the excessive urban development of the catchments, there is no natural sediment supply to the beach. The change in the typology of the sediment, from pebbles to sand, during the beach nourishments has led to a crucial imbalance in the studied area. Moreover, the beach area gained has disappeared, affecting the Posidonia oceanica meadow, and incrementing the erosion rates. The findings obtained are relevant, not only in the management and maintenance of the beaches, but also, in the decision-making for future nourishments.

17.
Sci Total Environ ; 543(Pt A): 493-504, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26599149

RESUMO

Human actions over rivers and coasts have generated great changes along seaboard. In order to know future development of those changes, it is necessary to understand the development of the coast during the past. When there is a complex morphologic system as a result of the combination of natural elements with human construction elements, the study of the abovementioned changes requires a wider perspective than the one provided by traditional two-dimensional methods. Thus, the Geographic Information Systems (GIS) become a suitable tool for that kind of studies. In this work, GIS are used to understand changes in bathymetry, sediments properties and transport, as well as surface variations of plant species occurred in the Segura River mouth (Spain) within a period of 17 years due to the channelization of the river low course. The methodology followed here implies the integration of data coming from different sources and with different formats in a GIS, what allows for a spatial analysis. Results obtained show the grain-size spatial distribution for every period of time studied, as well as bathymetry changes and seabed morphology. It can be concluded that the construction works carried out in the riverbed have affected sediment grain-size in the area. Clays have nearly disappeared and consequently there is a descent of seabed level that affects plant species, such as Posidonia oceanica.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/análise , Rios/química , Poluentes da Água/análise , Alismatales , Sistemas de Informação Geográfica , Espanha , Movimentos da Água
18.
J Investig Allergol Clin Immunol ; 25(3): 196-204, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26182686

RESUMO

BACKGROUND: Tomato allergies have been extensively studied but component-resolved in vivo diagnosis with purified allergens has yet to be performed. OBJECTIVES: To evaluate the prevalence of sensitization to Sola l 3 in a Mediterranean population, and to compare the resulting sensitization profile with that of individuals sensitized to tomato, peach, and/or purified lipid transfer protein (LTP). METHODS: Sola l 3 was purified, characterized, and used to prepare skin prick tests (SPTs). Two groups of patients were selected. Group 1 consisted of patients with at least 1 positive SPT to tomato, peach, or LTP mixture (marker extracts) who were subsequently tested with Sola l 3 (n = 280). Group 2 (prevalence study) consisted of patients who underwent simultaneous SPT with the 3 marker extracts and Sola l 3 (n = 658). Patients from either group who were positive to any of the 4 extracts were studied in detail (study group, n = 1 23). ELISA and immunoblot assays were performed in individuals with a positive SPT to Sola l 3 to detect the presence of specific IgE antibodies to this allergen. RESULTS: Prevalence of sensitization to Sola l 3 was 3.2% overall and 54.7% in tomato-positive patients. Most tomato-sensitized patients were asymptomatic. Symptoms were more common in Sola l 3-positive individuals. Sensitization to peach and the LTP mixture did not discriminate between Sola l 3-positive and Sola l 3-negative patients. CONCLUSIONS: This study confirms that LTP, not only from peach but also from other fruit and vegetables, including tomato, is an important allergen in the Mediterranean area. Sensitization to Sola l 3 is associated with more symptoms in tomato-sensitized patients.


Assuntos
Antígenos de Plantas , Proteínas de Transporte , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/imunologia , Técnicas de Diagnóstico Molecular , Proteínas de Plantas , Prunus/efeitos adversos , Solanum lycopersicum/efeitos adversos , Adolescente , Adulto , Antígenos de Plantas/imunologia , Biomarcadores/sangue , Proteínas de Transporte/imunologia , Reações Cruzadas , Feminino , Hipersensibilidade Alimentar/sangue , Hipersensibilidade Alimentar/epidemiologia , Frutas , Humanos , Imunoglobulina E/sangue , Testes Intradérmicos , Solanum lycopersicum/imunologia , Masculino , Proteínas de Plantas/imunologia , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Prunus/imunologia , Espanha/epidemiologia , Adulto Jovem
19.
Food Sci Technol Int ; 20(2): 119-26, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23744115

RESUMO

The formation of soluble melanoidins from a single combination of sugar (fructose) and amino acid model systems were evaluated kinetically. The selected amino acids, commonly found in apple juice and highly reactive in the Maillard reaction, were asparagine, aspartic acid, and glutamic acid. The effect of these reagents and the treatment at different temperatures (50 , 85 , and 100 ) during 96 h on the color intensity of the melanoidin formed was measured by absorbance at different wavelengths (280, 325, 405, and 420 nm). The absorbance of the melanoidin formed from all model systems was located on the wavelength of 405 nm, that is, the area of the visible spectrum close to the UV region. The color of the melanoidins was directly measured using the CIELAB color space system. A first-order kinetic model was applied to the evolution of the ΔE * (color difference) and L * (lightness) of the color. The fructose/aspartic acid model system values of a * (redness) and b * (yellowness) were found in the brown-red zone. Therefore, the color development of the melanoidins was influenced by the type of amino acid and temperature. Especially, it is thought that the a * and b * values can be used to explain the differences among the amino acids in the color development of melanoidins.


Assuntos
Aminoácidos/química , Frutose/química , Animais , Cinética , Polímeros/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA