2,252 research outputs found
On-line coupling of field-flow fractionation to optical spectroscopy and elemental mass spectrometry: a powerful strategy for characterization of engineered inorganic nanoparticles
El desarrollo de aplicaciones basadas en el empleo de nanopartículas (NPs) requiere disponer de herramientas analíticas capaces caracterizar apropiadamente la pureza química y el estado físico-químico de estas NPs, optimizar el proceso de solubilización/estabilización de las mismas y controlar procesos de funcionalización de su superficie con elementos de reconocimiento específico, tales como anticuerpos y aptámeros.
La técnica de “Asymmetric flow field flow fractionation” (AF4) presenta un gran potencial en nanociencia como herramienta de caracterización en el “nanomundo”, ya que permite llevar a cabo la separación, dependiente del tamaño, de partículas con tamaños en la nanoescala (desde < 1 nm hasta varios μm). El acoplamiento en línea del AF4 con diferentes detectores podría proporcionar análisis de gran valor sobre la calidad y composición química de las NPs.
Se mostrarán varios ejemplos en los que se hace uso del acoplamiento de AF4 a detectores de espectrofotometría VIS-UV, fluorescencia y de espectrometría de masas elemental para llevar a cabo el control de la calidad del producto resultante de la síntesis de nanopartículas inorgánicas así como para conseguir la evaluación, tanto cualitativa como cuantitativa, de la bioconjugation de distintos tipos de NPs a biomoléculas de distinta naturaleza. Este es un tema clave en el futuro desarrollo de aplicaciones analíticas y bioanalíticas de nanopartículas inorgánicas·.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Controlling ligand surface density on streptavidin-magnetic particles by a simple, rapid, and reliable chemiluminescent test
International audienc
Inorganic mass spectrometry as a tool for characterisation at the nanoscale
Inorganic mass spectrometry techniques may offer great potential for the characterisation at the nanoscale, because they provide unique elemental information of great value for a better understanding of processes occurring at nanometre-length dimensions. Two main groups of techniques are reviewed: those allowing direct solid analysis with spatial resolution capabilities, i.e. lateral (imaging) and/or indepth profile, and those for the analysis of liquids containing colloids. In this context, the present capabilities of widespread elemental mass spectrometry techniques such as laser ablation coupled with inductively coupled plasma mass spectrometry (ICP-MS), glow discharge mass spectrometry and secondary ion/neutral mass spectrometry are described and compared through selected examples from various scientific fields. On the other hand, approaches for the characterisation (i.e. size, composition, presence of impurities, etc.) of colloidal solutions containing nanoparticles by the well-established ICP-MS technique are described. In this latter case, the capabilities derived from the on-line coupling of separation techniques such as field-flow fractionation and liquid chromatography with ICP-MS are also assessed. Finally, appealing trends using ICP-MS for bioassays with biomolecules labelled with nanoparticles are delineated
Psychometric Properties of the Health Professionals Communication Skills Scale in University Students of Health Sciences
Communication is one of the determining factors of healthcare quality; however, a health model that prioritizes clinical over non-technical skills remains prevalent. The aims of this article were: (a) to validate a communication skills scale in a sample of fourth-year nursing degree students from two Spanish universities and (b) determine their perception of communication skills. The study included 289 fourth-year nursing undergraduate students with a mean age of 22.7 (SD = 4.87) years; 81.7% were female. The Health Professionals Communication Skills Scale (HP-CSS) questionnaire was adapted for use among nursing students. We analysed the psychometric properties and relationships with the variable attitudes toward communication skills. The HP-CSS showed a high internal consistency (0.88) and good fit of data to the model (TLI = 0.98; CFI = 0.97; RMSEA = 0.05 [95% CI = 0.04–0.06]). The total score and subscale scores correlated with the variable attitude towards communication skills. High scores were obtained for the students’ perception of communication skills. The HP-CSS is a valid and reliable tool to assess the communication skills in nursing students. This scale provides university teachers with a rapid and easily applied instrument to assess the level of communication skills and relationship with patients.This research was funded by Program Redes-I 3CE for Research in University Teaching of the Institute of Education Science (Vice-chancellorship of Quality and Educational Innovation) of the University of Alicante, edition 2018-19
Mass spectrometry for the characterization and quantification of engineered inorganic nanoparticles
Gas chromatography coupled to tunable pulsed glow discharge time-of-flight mass spectrometry for environmental analysis
A tuneable microsecond pulsed direct current glow discharge (GD)-time-of-flight mass spectrometer MS(TOF) developed in our laboratory was coupled to a gas chromatograph (GC) to obtain sequential collection of the mass spectra, at different temporal regimes occurring in the GD pulses, during elution of the analytes. The capabilities of this set-up were explored using a mixture of volatile organic compounds of environmental concern: BrClCH, Cl3CH, Cl4C, BrCl2CH, Br2ClCH, Br3CH. The experimental parameters of the GC-pulsed GD-MS(TOF) prototype were optimized in order to separate appropriately and analyze the six selected organic compounds, and two GC carrier gases, helium and nitrogen, were evaluated. Mass spectra for all analytes were obtained in the prepeak, plateau and afterpeak temporal regimes of the pulsed GD. Results showed that helium offered the best elemental sensitivity, while nitrogen provided higher signal intensities for fragments and molecular peaks. The analytical performance characteristics were also worked out for each analyte. Absolute detection limits obtained were in the order of ng. In a second step, headspace solid phase microextraction (HS SPME), as sample preparation and preconcentration technique, was evaluated for the quantification of the compounds under study, in order to achieve the required analytical sensitivity for trihalomethanes European Union (EU) environmental legislation. The analytical figures of merit obtained using the proposed methodology showed rather good detection limits (between 2 and 13 μg L−1 depending on the analyte). In fact, the developed methodology met the EU legislation requirements (the maximum level permitted in tap water for the “total trihalomethanes” is set at 100 μg L−1). Real analysis of drinking water and river water were successfully carried out. To our knowledge this is the first application of GC-pulsed GD-MS(TOF) for the analysis of real samples. Its ability to provide elemental, fragments and molecular information of the organic compounds is demonstrated
Evaluation of protective effect of different dietary fibers on polyphenolic profile stability of maqui berry (Aristotelia chilensis (Molina) Stuntz) during in vitro gastrointestinal digestion
The aim of this work was to determine the protective effect of different dietary fibers on (i) the recovery
and bioaccessibility indexes, and (ii) the stability of polyphenolic compounds (phenolic acids, flavonoids
and anthocyanins) of maqui berry powder subjected to in vitro gastrointestinal digestion (GID). The
extracts obtained in each phase (oral, gastric and intestinal) of GID were used to analyze the stability of
polyphenolic compounds by HPLC, and the bioaccessibility of these compounds was also determined. At
the end of the GID process, the mixture of maqui berry with the different fibers increased the bioaccessibility
index of the phenolic and flavonoid compounds in all cases. The results obtained suggest that the
anthocyanins and phenolic acids and flavonoid compounds present in maqui are stabilized through
dietary fiber interactions, which might provide sufficient levels for absorption during gastrointestinal
digestion. The gums sodium carboxymethyl cellulose, xanthan gum and guar gum provided the best protective
effect
Enhancing Energy Production with Exascale HPC Methods
High Performance Computing (HPC) resources have become the key actor for achieving more ambitious challenges in many disciplines. In this step beyond, an explosion on the available parallelism and the use of special purpose
processors are crucial. With such a goal, the HPC4E project applies new exascale HPC techniques to energy industry simulations, customizing them if necessary, and going beyond the state-of-the-art in the required HPC exascale
simulations for different energy sources. In this paper, a general overview of these methods is presented as well as some specific preliminary results.The research leading to these results has received funding from the European Union's Horizon 2020 Programme (2014-2020) under the HPC4E Project (www.hpc4e.eu), grant agreement n° 689772, the Spanish Ministry of
Economy and Competitiveness under the CODEC2 project (TIN2015-63562-R), and
from the Brazilian Ministry of Science, Technology and Innovation through Rede
Nacional de Pesquisa (RNP). Computer time on Endeavour cluster is provided by the
Intel Corporation, which enabled us to obtain the presented experimental results in
uncertainty quantification in seismic imagingPostprint (author's final draft
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