Evolution and applications of the QuEChERS method González-Curbelo, M.Á.; Socas-Rodríguez, B.; Herrera-Herrera, A.V. ...
TrAC, Trends in analytical chemistry (Regular ed.),
09/2015, Letnik:
71
Journal Article
Recenzirano
•QuECHERS (quick, easy, cheap, effective, rugged, and safe) method for analysis.•QuECHERS is the most frequent sample pretreatment in residue laboratories.•QuECHERS applied for the extraction of a ...wide diversity of analytes and matrices.•Modified QuECHERS improved recoveries, and avoided degradation and matrix effects.•QuEChERS has mainly been combined with LC-MS and GC-MS.
It is widely recognized that the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method is relevant in pesticide residue analysis. Many official laboratories around the globe are routinely using it due to the advantages encapsulated in its name. However, the frontiers of the application of QuEChERS are not yet established. The method is effective for the analysis of other groups of compounds, including pharmaceuticals, mycotoxins, and polycyclic aromatic hydrocarbons, in a wide variety of complex matrices. This review article provides a general overview of the most relevant modifications of the QuEChERS method that have been widely accepted and applied (including both extraction and clean-up) and a general view of the different groups of compounds to which it has been fruitfully applied. We do not include those approaches where only half the method has been used.
Abstract
A simple method for the preparation of iron/iron oxide nanoparticles with core/shell cubic morphology is presented. The synthesis of the nanocubes was carried out through decomposition of a ...preformed iron oleate complex at high temperature. Although this procedure has been shown previously to produce monodisperse magnetite spheres,
1
the use of squalene as a solvent and the presence of sodium oleate was found to induce cube formation. A detailed high‐resolution transmission electron microscopy (HRTEM) analysis of the nanocubes was performed for structural characterization. The core/shell structure, an iron core surrounded by magnetite (Fe
3
O
4
) shell, was confirmed by fast Fourier transform (FFT) filtering analysis. The results obtained by HRTEM analysis are in agreement with X‐ray Photoelectron Spectroscopy (XPS) and magnetic analysis. The Fe nanocubes are superparamagnetic at room temperature with a saturation magnetization
M
S
= 101 A m
2
kg
–1
and magnetic anisotropy density
K
eff
= 1.6 × 10
5
J m
–3
at low temperatures.
Context.
LBQS 0302−0019 is a blue quasar (QSO) at
z
∼ 3.3 that hosts powerful outflows and resides in a complex environment consisting of an obscured active galactic nucleus (AGN) candidate and ...multiple companions, all within 30 kpc in projection.
Aims.
We aim to characterise this complex system using JWST NIRSpec Integral Field Spectrograph (IFS) observations obtained as part of the NIRSpec IFS GTO programme “Galaxy Assembly with NIRSpec IFS” (GA-NIFS); these data cover the QSO rest-frame optical emission lines with a spatial resolution of ∼0.1″ and a sampling of 0.05″ (∼380 pc) over a contiguous sky area of ∼3″ × 3″ (23 × 23 kpc
2
).
Methods.
We developed a procedure to correct for the spurious oscillations (or “wiggles”) in NIRSpec single-spaxel spectra caused by the spatial under-sampling of the point spread function. We performed a QSO–host decomposition with the QD
EBLEND
3D tools. We used multi-component kinematic decomposition of the optical emission line profiles to infer the physical properties of the emitting gas in the QSO environment.
Results.
The QSO–host decomposition allows us to identify both a low- and a high-velocity component. The former possibly traces a warm rotating disk with a dynamical mass
M
dyn
∼ 10
11
M
⊙
and a rotation-to-random motion ratio
v
rot
/
σ
0
∼ 2. The other kinematic component traces a spatially unresolved ionised outflow with a velocity of ∼1000 km s
−1
and an outflow mass rate of ∼10
4
M
⊙
yr
−1
. We clearly detect eight companion objects close to LBQS 0302−0019. For two of them, we detect a regular velocity field that likely traces rotating gas, and we infer individual dynamical masses of ≈10
10
M
⊙
. Another companion shows evidence of gravitational interaction with the QSO host. Optical line ratios confirm the presence of a second, obscured AGN ∼20 kpc from the primary QSO; the dual AGN dominates the ionisation state of the gas in the entire NIRSpec field of view.
Conclusions.
This work has unveiled in unprecedented detail the complex environment of LBQS 0302−0019, which includes its host galaxy, a close obscured AGN, and nine interacting companions (five of which were previously unknown), all within 30 kpc of the QSO. Our results support a scenario where mergers can trigger dual AGN and can be important drivers of rapid early supermassive black hole growth.
The magnetic metal-organic framework Fe3O4@(Fe-(benzene-1,3,5-tricarboxylic acid) (MMOF) was prepared, characterized and studied as a magnetic sorbent for the dispersive solid-phase extraction (DSPE) ...of several widely used blood lipid regulators (i.e., bezafibrate, clofibric acid, clofibrate, gemfibrozil and fenofibrate) from water samples. Characterization of the synthesized Fe3O4@Fe-BTC magnetic nanomaterial was performed by Fourier transform infrared spectroscopy, powder X-ray diffractometry, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The magnetic nanocomposite was found to be chemically stable and to possess a large surface area (803.62 m2/g) and pore volume (0.59 cm³/g). The concentrations of fibrates in different water samples were determined using HPLC-UV-Vis and confirmed by UPLC-MS/MS. Parameters affecting the extraction efficiency of magnetic-DSPE were studied and optimized. The maxima absorption capacities (Qmax) were determined to be (in mg/g) 197.0 for bezafibrate, 620.3 for clofibric acid, 537.6 for clofibrate, 288.7 gemfibrozil and 223.2 for fenofibrate. Validations of the optimized magnetic DSPE method for analyses at two fibrate concentrations in spiked water samples produced relative recovery values ≤ 70% for clofibrate and within the range of 80–100% for bezafibrate, clofibric acid, gemfibrozil and fenofibrate. LODs ranging from 4 μg/L for fenofibrate to 99 μg/L for gemfibrozil were obtained. The validated methodology produced recovery values ranging from 70 to 112% (relative standard deviations < 7%).
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•Nano-Fe3O4@MOFs composite having super paramagnetism was applied as sorbent for DSPE.•The optimized methodology was validated using drugs with diverse physico-chemical properties.•Synthesized material presents high extraction efficiency for various fibric acid derivatives.•LODs from 4 μg/L to 99 μg/L were obtained, requiring only 10 mL of water sample.
Abstract
We present a general qubit-boson interaction Hamiltonian that describes the Jaynes–Cummings model and its extensions as a single Hamiltonian class. Our model includes non-linear processes ...for both the free qubit and boson field as well as non-linear, multi-boson excitation exchange between them. It shows an underlying algebra with supersymmetric quantum mechanics features allowing an operator based diagonalization that simplifies the calculations of observables. As a practical example, we show the evolution of the population inversion and the boson quadratures for an initial state consisting of the qubit in the ground state interacting with a coherent field for a selection of cases covering the standard Jaynes–Cummings model and some of its extensions including Stark shift, Kerr-like, intensity dependent coupling, multi-boson exchange and algebraic deformations.
(Aided) phytostabilisation has been proposed as a suitable technique to decrease the environmental risks associated with metal(loid)-enriched mine tailings. Field scale evaluations are needed for ...demonstrating their effectiveness in the medium- to long-term. A field trial was implemented in spring 2011 in Cu-rich mine tailings in the NW of Spain. The tailings were amended with composted municipal solid wastes and planted with Salix spp., Populus nigra L. or Agrostis capillaris L. cv. Highland. Plant growth, nutritive status and metal accumulation, and soil physico- and bio-chemical properties, were monitored over three years (four years for plant growth). The total bacterial community, α- and β-Proteobacteria, Actinobacteria and Streptomycetaceae were studied by DGGE of 16s rDNA fragments. Compost amendment improved soil properties such as pH, CEC and fertility, and decreased soil Cu availability, leading to the establishment of a healthy vegetation cover. Both compost-amendment and plant root activity stimulated soil enzyme activities and induced important shifts in the bacterial community structure over time. The woody plant, S. viminalis, and the grassy species, A. capillaris, showed the best results in terms of plant growth and biomass production. The beneficial effects of the phytostabilisation process were maintained at least three years after treatment.
•Compost amendment reduced soil acidity, improved fertility and decreased available Cu.•Reduced phytotoxicity enabled the establishment of a grass cover and short rotation coppice system.•Soil enzyme activities increased after compost addition and were highest under Salix viminalis.•Shifts in bacterial community structure were associated with amendments and plant species.•Organic wastes can be effectively incorporated into phytostabilisation techniques.
Gold nanorods with well‐defined aspect ratios are homogeneously incorporated within poly(vinyl alcohol) thin films and subsequently aligned by heating and stretching the nanocomposite films. The ...spatial alignment of the nanorods is directly proved using transmission electron microscopy. The polarization‐dependent optical response of the rods is measured and compared with a dipole model. Excellent agreement is found. Additionally, irradiation of the film with nanosecond laser pulses (1064 nm) leads to selective reshaping of the nanorods into nanospheres, and we demonstrate that this effect can be used to micropattern optical structures into the films.
Gold nanorods have been aligned within poly(vinyl alcohol) thin films by stretching the film, thereby allowing the polarization‐dependent optical response to be studied (see Figure). Irradiation with a nanosecond laser was used to micropattern the film, by the thermal reshaping of the nanorods into nanospheres.
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•Aqueous extract of Cystoseira baccata served to synthesize gold nanoparticles Au@CB.•Au@CB are spherical polycrystalline nanoparticles with a mean diameter of 8.4nm.•Au@CB exhibit ...strong cytotoxicity against Caco-2 and HT-29 and no effect on the healthy cells.•Au@CB induce apoptosis activation by the extrinsic and mitochondrial pathway.
This study is the first dealt with the use of brown macroalgae Cystoseira baccata (CB) extracts in obtaining gold nanoparticles (Au@CB) through an eco-friendly, fast, one-pot synthetic route. The formation of spherical, stable, polycrystalline nanoparticles with mean diameter of 8.4±2.2nm was demonstrated by UV–vis spectroscopy, TEM, HRTEM, STEM and zeta potential measurements. The extract appears to act as a protective agent where the particles are embedded, keeping them separated, avoiding aggregation and coalescence. The EELS and EDS analyses confirmed the elemental composition of the extract and nanoparticles. Moreover, the functional group of biomolecules present in CB and Au@CB were characterized by FTIR. The effects of CB extract and Au@CB were tested in vitro on the colon cancer cell lines HT-29 and Caco-2, as well as on normal primary neonatal dermal fibroblast cell line PCS-201-010. Results show a stronger cytotoxic effect against HT-29 than that on Caco-2; interestingly, a lack of toxicity on PCS-201-010 was obtained. Finally, the apoptotic activity was determined; Au@CB is able to induce apoptosis activation by the extrinsic and mitochondrial pathway in our CRC in vitro model. These encouraging results suggest that Au@CB has a significant potential for the treatment of colon rectal cancer.
Introduction
Early intervention on a first psychotic episode is fundamental for a more favorable prognosis, and it usually combines pharmacological treatment, which mainly affects positive psychotic ...symptoms, with interventions that can improve the rest of the symptoms and associated problems such as deterioration in social functioning (Harvey & Penn, 2010; Fusar-Poli, McGorry & Kane, 2017). While Mindfulness is gaining more and more prominence in the field of psychotherapy (Chan et al., 2019; Cillesen et al., 2019), social cognition and social functioning are being researched as key targets on which to intervene after a first psychotic episode (Green, Horan & Lee, 2015).
SocialMIND® is a mindfulness-based social cognition training tailor-made to improve social functioning in people who have suffered a first psychotic episode within the last five years. It is currently being compared with a group Psychoeducational Multicomponent Intervention (PMI) in a Randomized Controlled Trial (RCT) (Mediavilla et al., 2019). Both group psychotherapies include 17 sessions delivered over a 9 month period: 8 weekly sessions, 4 biweekly sessions and 5 monthly sessions.
The results of SocialMIND® at 8 weeks showed improvements in social cognition and social functioning, specifically on affective social cognition and self-care (Mediavilla et al., 2021).
Objectives
To evaluate the efficacy of SocialMIND® in improving social functioning, measured by the Personal and Social Functioning (PSP) scale 16 weeks after starting the intervention, in people who have suffered a first psychotic episode in the last 5 years.
Methods
Randomized, controlled pilot trial (use of a psychoeducational multicomponent intervention or PMI as active comparator) of two parallel groups (SocialMIND® and PMI) with a 1:1 ratio using a blind evaluator.
Results
No statistically significant differences were found in the social functioning variable between the two treatment arms. Intragroup differences are observed in other secondary variables studied (social cognition) 16 weeks after starting the interventions.
Conclusions
SocialMIND® has not been shown to be more effective than a PMI in improving social functioning at 16 weeks after starting the intervention in people who have suffered a first psychotic episode in the five years prior to being included in the study.
Disclosure of Interest
None Declared
The alarming increase of antibiotic-resistant bacteria, causing conventional treatments of bacterial infections to become increasingly inefficient, is one of the biggest threats to global health. ...Here, we have developed probiotic cellulose, an antibiotic-free biomaterial for the treatment of severe skin infections and chronic wounds. This composite biomaterial was in-depth characterized by Gram stain, scanning electron microscopy (SEM) and confocal fluorescence microscopy. Results demonstrated that probiotic cellulose consists of dense films of cellulose nanofibers, free of cellulose-producing bacteria, completely invaded by live probiotics (Lactobacillus fermentum or Lactobacillus gasseri). Viability assays, including time evolution of pH and reducing capacity against electrochromic polyoxometalate, confirmed that probiotics within the cellulose matrix are not only alive but also metabolically active, a key point for the use of probiotic cellulose as an antibiotic-free antibacterial biomaterial. Antibacterial assays in pathogen-favorable media, a real-life infection scenario, demonstrated that probiotic cellulose strongly reduces the viability of Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA), the most active pathogens in severe skin infections and chronic wounds. Likewise, probiotic cellulose was also found to be effective to inhibit the proliferation of methicillin-resistant SA (MRSA). The combination of the properties of bacterial cellulose as wound dressing biomaterial and the antibacterial activity of probiotics makes probiotic cellulose an alternative to antibiotics for the treatment of topical infections, including severe and hard-to-heal chronic wounds. In addition, probiotic cellulose was obtained by a one-pot synthetic approach under mild conditions, not requiring the long and expensive chemical treatments to purify the genuine bacterial cellulose.
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