Detección de microplásticos a través de ICP-MS

En este trabajo se estudia la viabilidad de ICP-MS para la detección de microplásticos.Se me ha indicado cambiar la portada, este trabajo contiene la portada correcta.<br /

High-precision isotopic analysis sheds new light on mercury metabolism in long-finned pilot whales (Globicephala melas)

Eduardo Bolea-Fernandez acknowledges BOF-UGent for his postdoctoral grant. We acknowledge Arnout Laureys for his support, Jonas Kunigkeit and Magali Perez for isolation of HgSe particles, and Dr. Andrew Brownlow for given access to the Pilot Whale samples.Peer reviewedPublisher PD

Tracing Mercury Pollution along the Norwegian Coast via Elemental, Speciation, and Isotopic Analysis of Liver and Muscle Tissue of Deep-Water Marine Fish (Brosme brosme)

Liver and muscle tissue of tusks (Brosme brosme) have been analyzed for their THg and MeHg concentrations and Hg isotopic signatures for tracing Hg pollution along the Norwegian coast. Clear differences between tissue types and locations were established. At five of the eight locations, the Hg concentration in muscle exceeded the maximum allowable level of 0.5 mg kg–1 wet weight. δ202Hg values in both tissue types indicated that Hg speciation affects the bulk Hg isotopic signature. Tusk liver seems to be more sensitive to immediate changes and to anthropogenic inorganic Hg, while the muscle rather reflects the Hg accumulated over a longer period of exposure. The δ202Hg values of liver and muscle also enabled different sources of Hg and exposure pathways to be distinguished. δ202Hgmuscle–δ202Hgliver showed a clear correlation with the % MeHg in tusk liver for the coastal waters, but not for the fjords. The absence of significant differences in Δ199Hg values between both tissues of tusk from the same location suggests that in vivo metabolic processes are the underlying reason for the differences in Hg speciation and in δ202Hg values. This work highlights the importance of selecting different tissues of marine fish in future Hg monitoring programs.publishedVersio

Serum Mg isotopic composition reveals that Mg dyshomeostasis remains in type 1 diabetes despite the resolution of hypomagnesemia

Hypomagnesemia was historically prevalent in individuals with type 1 diabetes mellitus (T1DM), but contemporary results indicate an incidence comparable to that in the general population, likely due to improved treatment in recent decades, resulting in better glycemic control. However, a recent study found a significant difference between the serum Mg isotopic composition of T1DM individuals and controls, indicating that disruptions to Mg homeostasis persist. Significant deviations were also found in samples taken one year apart. To investigate whether the temporal variability in serum Mg isotopic composition is linked to the transient impact of administered insulin, Mg isotope ratios were determined in serum from 15 T1DM individuals before and one hour after insulin injection/meal consumption using multi-collector inductively coupled plasma-mass spectrometry. Consistent with results of the previous study, significant difference in the serum Mg isotopic composition was found between T1DM individuals and 10 sex-matched controls. However, the average difference between pre- and post-insulin injection/meal T1DM samples of 0.05 ± 0.13‰ (1SD) was not significant. No difference was observed for controls before (−0.12 ± 0.16‰) and after the meal (−0.10 ± 0.13‰) either, suggesting a lack of a postprandial Mg isotopic response within one hour of food consumption, and that the timing of the most recent meal may not require controlling for when determining serum Mg isotopic composition

V-Proportion: a method based on the Voronoi diagram to study spatial relations in neuronal mosaics of the retina

The visual system plays a predominant role in the human perception. Although all components of the eye are important to perceive visual information, the retina is a fundamental part of the visual system. In this work we study the spatial relations between neuronal mosaics in the retina. These relations have shown its importance to investigate possible constraints or connectivities between different spatially colocalized populations of neurons, and to explain how visual information spreads along the layers before being sent to the brain. We introduce the V-Proportion, a method based on the Voronoi diagram to study possible spatial interactions between two neuronal mosaics. Results in simulations as well as in real data demonstrate the effectiveness of this method to detect spatial relations between neurons in different layers

Social Skills and Psychological Disorders: Converging and Criterion-Related Validity for YSR and IHSA-Del-Prette in Adolescents at Risk

This study evaluated indexes of converging and criterion-related validity for the Social Skills Inventory for Adolescents (IHSA-Del-Prette) and the Youth Self-Report (YSR) in two samples: one referring to clinical service (CLIN), with 28 adolescents (64.3% boys), 11 through 17 years old (M = 13.75; SD = 1.74), and the other referring to a psycho-educational program (PME = 46.2%), mainly composed of boys (91.7%) aged 13 through 17 (M = 15.33; SD = 1.47). Both samples completed the two inventories. Results showed a high incidence of psychological disorders in both samples (between 4% and 79% in the borderline or clinical range on YSR scales) and accentuated deficits in the general and subscale scores of IHSA-Del-Prette, especially on the frequency scale (25% to 58%). The correlations between the instruments in the two groups supported criterion-related and converging validity. Some issues concerning the differences between the samples and about the construct of social competence, underlying these inventories, are discussed. Key words authors

Results of an interlaboratory comparison for characterization of Pt nanoparticles using single-particle ICP-TOFMS

This study describes an interlaboratory comparison (ILC) among nine (9) laboratories to evaluate and validate the standard operation procedure (SOP) for single-particle (sp) ICP-TOFMS developed within the context of the Horizon 2020 project ACEnano. The ILC was based on the characterization of two different Pt nanoparticle (NP) suspensions in terms of particle mass, particle number concentration, and isotopic composition. The two Pt NP suspensions were measured using icpTOF instruments (TOFWERK AG, Switzerland). Two Pt NP samples were characterized and mass equivalent spherical sizes (MESSs) of 40.4 ± 7 nm and 58.8 ± 8 nm were obtained, respectively. MESSs showed <16% relative standard deviation (RSD) among all participating labs and <4% RSD after exclusion of the two outliers. A good agreement was achieved between the different participating laboratories regarding particle mass, but the particle number concentration results were more scattered, with <53% RSD among all laboratories, which is consistent with results from previous ILC studies conducted using ICP-MS instrumentation equipped with a sequential mass spectrometer. Additionally, the capabilities of sp-ICP-TOFMS to determine masses on a particle basis are discussed with respect to the potential for particle density determination. Finally, because quasi-simultaneous multi-isotope and multi-element determinations are a strength of ICP-TOFMS instrumentation, the precision and trueness of isotope ratio determinations were assessed. The average of 1000 measured particles yielded a precision of below ±1% for intensity ratios of the most abundant Pt isotopes, i.e.194Pt and 195Pt, while the accuracy of isotope ratios with the lower abundant isotopes was limited by counting statistics