56 research outputs found
Análisis del índice de distensibilidad de la vena yugular interna evaluada por ecografía como predictor de la respuesta al volumen en el paciente conectado a ventilación mecánica
Introducción
La fluidoterapia es una de las principales herramientas en la optimización hemodinámica
de los pacientes en shock. Disponer de sistemas que permitan saber si un paciente es
candidato a un bolo de líquidos es de gran importancia. El objetivo de este estudio es
comprobar si el análisis de la distensibilidad de la vena yugular interna evaluada por
ecografía en pacientes conectados a ventilación mecánica puede ser usada como predictor
de la respuesta a la expansión con volumen en estos pacientes.
Materiales y métodos
En un grupo de pacientes considerados potencialmente respondedores a volumen de
acuerdo con sistemas de análisis de la onda del pulso se realizó el análisis de la
distensibilidad de la vena yugular interna mediante ecografía antes y después de la
administración de un bolo de 500 mL de cristaloides.
Resultados
Entre los 15 pacientes reclutados en este estudio no se observaron diferencias
estadísticamente significativas entre el tipo de cirugía y los valores estudiados, existiendo
una correlación directa entre la variación del volumen sistólico y la distensibilidad de la
vena yugular interna. El ajuste lineal de la variación del volumen sistólico con la vena
cava inferior fue pobre.
Conclusión
Los hallazgos presentados en este estudio fortalecen el uso de la ecografía de la vena
yugular interna como predictor de respuesta al volumen. La combinación de la ecografía
junto con otros métodos de predicción de esta respuesta puede reforzar la toma de
decisiones.Introduction
Fluid therapy is one of the main tools in the hemodynamic optimization of patients in
shock. It is of great importance to have systems to know if a patient is a candidate for a
fluid bolus. The objective of this study is to verify whether the analysis of the compliance
of the internal jugular vein evaluated by ultrasound in patients connected to mechanical
ventilation can be used as a predictor of the volume responsiveness.
Materials and methods
In a group of potentially volume-responsive patients according to pulse wave analysis
systems, ultrasound was performed by analysing the compliance of the internal jugular
vein before and after the administration of a 500 mL bolus of crystalloids.
Results
Among 15 patients recruited in this study, no statistically significant differences were
observed between the type of surgery and the values studied, existing a direct correlation
between stroke volume variation and internal jugular vein compliance. The linear fit of
stroke volume variation and the inferior vena cava compliance is poor.
Conclusion
The findings of this study reinforce the use of internal jugular vein ultrasound as a
predictor of volume responsiveness. The combination of ultrasound along with other
methods of predicting this response can support decision-making
New extraction protocols for the determination of endocrine disrupting compounds in samples of environmental and agri-food interest
Humans are highly exposed to endocrine disrupting compounds (EDCs) due to the multiple contamination sources and accessible routes to the organism, including oral consumption, skin contact, inhalation, etc. It has been demonstrated that these compounds are responsible for several health disorders and diseases related with the endocrine system which also include some types of cancer. Among the wide variety of EDCs currently known, those with oestrogenic activity have arisen great interest in the scientific community.
Among the existing EDCs, the presence of natural oestrogens, which are steroid hormones produced by mammalians, should be highlighted, since they are involved in very important processes, being responsible for the development of female secondary sex characters, among other functions. Besides, there is also a wide variety of other natural as well as synthetic EDCs that can interact with the oestrogenic receptors by mimicking the activity of oestrogens when such compounds reach the organism. In this sense, some of them are used as growth promoters of livestock and in veterinary treatments, which constitutes the main source of their presence in the environment and in food of animal origin (i.e. meat, milk and dairy products). Furthermore, the so-called mycoestrogens and phytoestrogens also constitute an important source of contamination especially for humans. With respect to phthalic acid esters (PAEs), which also have endocrine disrupting activity, their use as plasticisers in industrial applications stands out from any other. While it is true that plastics are polymers of high molecular weight which do not normally constitute a risk for humans, these additives are not chemically bonded to them and show a great tendency to migrate to the surrounding environment. This fact, together with the notably increase of plastics production during the last decades, which has brought with it a great plastic waste generation and accumulation both in terrestrial and aquatic environments as a result of their improper management, have widely distributed them up to the point that they have been found in environmental waters, food, soils and even in the atmosphere, constituting a really serious risk for humans.
The uncountable sources of contamination to which humans are exposed and the low concentrations at which these EDCs can produce such serious effects on health, make necessary the development of new effective and sensitive analytical methodologies to allow their determination at the low levels at which they appear in environmental and food matrices. In this sense, the use of new sorbents and miniaturised techniques which allow a high extraction efficiency, selectivity and sensitivity, with low consumption of reagents and organic solvents, have become important alternatives to address their analysis.
Thus, in this PhD Thesis, new effective and sensitive analytical methodologies have been developed for the determination of a wide group of EDCs (natural, synthetic and myco-oestrogens as well as PAEs) in matrices of environmental and agri-food interest. Selective extraction techniques such as hollow-fibre liquid-phase microextraction, solid-phase extraction using molecularly imprinted polymers, and magnetic and non-magnetic micro-dispersive solid-phase extraction using different nanomaterials as sorbents (polydopamine magnetic nanoparticles, carbon nanotubes and metal-organic frameworks), have been applied to achieve this goal. All these procedures have been combined with high-performance liquid chromatography and gas chromatography mass spectrometry for the suitable separation and determination of the target analytes
Recycled wastewater as a potential source of microplastics in irrigated soils from an arid-insular territory (Fuerteventura, Spain)
In this work, the occurrence of microplastics (MPs) in irrigation recycled wastewaters (RWWs) and a desalinated brackish water (DBW) from the arid territory of Fuerteventura (Canary Islands, Spain) was studied. Besides, the presence of MPs in two types of soils (sandy-loam and clay-loamy; with no mulch film or fertilization with sewage sludge applied) irrigated with both water qualities was addressed. Results showed the prevalence presence of cellulosic and polyester microfibers (between 84.4 and 100%) of blue and transparent colors (up to 55.6 and 33.3%, respectively), with an average length of 786.9 ± 812.1 μm in the water samples. DBW had the lowest MP concentration (2.0 ± 2.0 items·L−1) while RWW showed concentrations up to 40.0 ± 19.0 items·L−1. Similarities were also observed between the MPs types and sizes found in both soils top layer (0–5 cm), with an average concentration three times greater in soil irrigated with RWW than in soil under DBW irrigation (159 ± 338 vs. 46 ± 92 items·kg−1, respectively). In addition, no MPs were extracted from non-irrigated/non-cultivated soils, suggesting agricultural activities as the unique source of MPs in soils of this arid area. Results show that RWWs constitute a potential source of MPs in irrigated soils that should be considered among other pros and cons linked to the use of this water quality in agricultural arid land
Microplastics in snow of a high mountain national park: El Teide, Tenerife (Canary Islands, Spain)
Human activities have introduced high amounts of microplastics (MPs) into the atmosphere that can be transported long distances and be later deposited in terrestrial and aquatic ecosystems with precipitation (rain or snow). In this work, it has been assessed the presence of MPs in the snow of El Teide National Park (Tenerife, Canary Islands, Spain, 2150–3200 m above sea level) after two storm episodes (January–February 2021). The data set (63 samples) was divided into three groups: i) samples from “accessible areas” (after the first storm episode and in places with a strong previous/recent anthropogenic activity); ii) “pristine areas” (after the second storm episode, in places with no previous anthropogenic activity), and iii) “climbing areas” (after the second storm episode, in places with a soft recent anthropogenic activity). Similar pattern profiles were observed among sampling sites in terms of morphology, colour and size (predominance of blue and black microfibers of 250–750 μm length), as well as in composition (predominance of cellulosic -either natural or semisynthetic-, with a 62.7 %, polyester, 20.9 %, and acrylic, 6.3 %, microfibers); however, significant differences in MPs concentrations were found between samples collected in pristine areas (average concentration of 51 ± 72 items/L) and those obtained in places with a previous anthropogenic activity (average concentration of 167 ± 104 and 188 ± 164 items/L in “accessible areas” and “climbing areas”, respectively). This study shows, for the first time, the presence of MPs in snow samples from a high altitude protected area on an insular territory and suggests that the sources of these contaminants could be atmospheric transport and local human outdoor activitie
Determination of phthalic acid esters and di(2-ethylhexyl) adipate in fish and squid using the ammonium formate version of the QuEChERS method combined with gas chromatography mass spectrometry
In the present study, the ammonium formate version of the QuEChERS method, considered highly advantageous
in relation to instrument maintenance and other issues, was applied for the first time to extract a group of twelve
phthalic acid esters (PAEs, i.e. dipropyl phthalate, DPP; diisobutyl phthalate, DIBP; dibutyl phthalate, DBP;
diisopentyl phthalate, DIPP; di-n-pentyl phthalate, DNPP; dihexyl phthalate, DHP; butyl benzyl phthalate, BBP;
dicyclohexyl phthalate, DCHP; di(2-ethylhexyl) phthalate, DEHP; di-n-octyl phthalate, DNOP; diisononyl
phthalate, DINP; and diisodecyl phthalate, DIDP) and one adipate (di(2-ethylhexyl) adipate, DEHA) from two
species of fish (Scomber colias and Katsuwonus pelamis) and one of squid (Loligo gahi). The method was validated
in terms of linearity, trueness and matrix effects. Determination coefficients (R2
) for matrix-matched calibration
curves were higher than 0.99 in all cases, being the lowest calibration levels in the range 0.5–10 ng/g. Mean
recovery values were between 70 and 117% with relative standard deviation values ≤20%. Matrix effects were
soft (between − 20 and +20%) for most analytes and matrices, except in squid samples, which was mostly
medium with a moderate ion suppression. The analysis of 10 samples of each type showed the presence of DIBP,
DBP and DEHP at concentrations up to 44.2 ± 2.1 ng/g of wet weight in some of the samples and species, still not
representing concerning values when considering the daily intake of such species of seafood in the human diet
(tolerable daily intake -TDI- values were not exceeded). Results demonstrated that the ammonium formate
version of the QuEChERS method can be applied with success for the extraction and determination of the selected
PAEs and DEHA in fish and squid samples.info:eu-repo/semantics/publishedVersio
Microplastics determination in gastrointestinal tracts of european sea bass (Dicentrarchus labrax) and gilt-head sea bream (Sparus aurata) from Tenerife (Canary Islands, Spain)
Microplastic pollution has an extremely widespread distribution, to the extent that microplastics could be ingested by aquatic organisms, including species of commercial importance for fisheries and aquaculture. In this work, the anthropogenic particles content of the gastrointestinal tracts of 86 individuals of cultivated European sea bass (Dicentrarchus labrax, n = 45) and gilt-head sea bream (Sparus aurata, n = 41) from Tenerife (Canary Islands, Spain) was determined. Samples were bought at local markets and directly transported to the laboratory. After the dissection of the fishes and digestion of the gastrointestinal tracts in 10% KOH (w/v) at 60◦C for 24 h, the digests were filtered (50 µm stainless-steel mesh) and visualized under a stereomicroscope, finding that most of the items were colourless (47.7% for Dicentrarchus labrax and 60.9% for Sparus aurata) and blue (35.3% vs. 24.8%) microfibers, with an average length of 1957 ± 1699 µm and 1988 ± 1853 µm, respectively. Moreover, 15.3% of the microfibres were analysed by Fourier transform infrared spec-troscopy, showing the prevalence of cellulosic fibres together with polyester, polyacrylonitrile, and poly(ether-urethane). This pattern (microplastics shapes, colours, sizes, and composition) clearly agrees with previous studies carried out in the Canary Islands region regarding the determination of microplastics in the marine environmen
Microplastic pollution in sublittoral coastal sediments of a North Atlantic island: The case of La Palma (Canary Islands, Spain)
In this work, the microplastic content of sediments collected in July 2020 between 5 and 7 m depth was studied in four locations of La Palma island (Canary Islands, Spain). At each sampling location, three samples were taken parallel to the shoreline. The microplastic content in each sampling corer was studied every 2.5 cm depth after digestion with a H2O2 solution followed by flotation in a saturated NaCl solution. Visualization of the final filtrates under a stereomicroscope revealed that all the sediment samples evaluated contained mostly microfibers (98.3%) which were mainly white/colorless (86.0%) and blue (9.8%), with an average length of 2423 ± 2235 (SD) mm and an average concentration of 2682 ± 827 items per kg of dry weight, being the total number of items found 1,019. Fourier Transform Infrared microscopy analysis of 13.9% (n = 139) of the microfibers also showed that they were mainly cellulosic (81.3%). No significant differences were found between the depths of the sediment. However, significant differences were found between the number of fibers from the sampling sites at the east and west of the island. Such variability could be driven by the winds and ocean mesoscale dynamics in the area. This study confirms the wide distribution of microfibers in sediments from an oceanic island like La Palma, providing their first report in marine sediments of the Canary Islands.En prensa3,20
A nationwide monitoring of atmospheric microplastic deposition
8 Pág.Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 μm to 398 μm, with a median value of 71 μm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition.The authors acknowledge the support provided by Spanish Network of Plastics in the Environment, EnviroPlaNet (www.enviroplanet.net) and the financial support provided by the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22. The authors would like to thank the Interdepartmental Investigation Research Service of the Universidad Autónoma de Madrid (SIDI-UAM and Segainvex) for the use of their infrastructures and their technical support. J.G.S. thanks ACIISI for the contract from the Viera y Clavijo program at the University of La Laguna (85 % co-financed by the European Social Fund).Peer reviewe
Izaña Atmospheric Research Center. Activity Report 2015-2016
This report is a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues
Izaña Atmospheric Research Center. Activity Report 2019-2020
Editors: Emilio Cuevas, Celia Milford and Oksana Tarasova.[EN]The Izaña Atmospheric Research Center (IARC), which is part of the State Meteorological Agency of Spain (AEMET), is a site of excellence in atmospheric science. It manages four observatories in Tenerife including the high altitude Izaña Atmospheric Observatory. The Izaña Atmospheric Observatory was inaugurated in 1916 and since that date has carried out uninterrupted meteorological and climatological observations, contributing towards a unique 100-year record in 2016.
This reports are a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues.[ES]El Centro de Investigación Atmosférica de Izaña (CIAI), que forma parte de la Agencia Estatal de Meteorología de España (AEMET), representa un centro de excelencia en ciencias atmosféricas. Gestiona cuatro observatorios en Tenerife, incluido el Observatorio de Izaña de gran altitud, inaugurado en 1916 y que desde entonces ha realizado observaciones meteorológicas y climatológicas ininterrumpidas y se ha convertido en una estación centenaria de la OMM.
Estos informes resumen las múltiples actividades llevadas a cabo por el Centro de Investigación Atmosférica de Izaña. El liderazgo del Centro en materia de investigación y desarrollo con respecto a las técnicas de medición, calibración y validación de última generación, así como la cooperación internacional, le han otorgado una reputación sobresaliente en lo que se refiere al tiempo, el clima, la hidrología y otros temas ambientales afines
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