One-step determination of total iron using deferiprone or kojic acid as colorimetric reagents

The role of iron, one of the most common metals in the environment, is fundamental in many biological and geochemical processes, which determine its availability in the two main oxidation states Fe2+ and Fe3+. Its relevance in the environment, industrial applications, and human physiology, as well as in many other fields has constantly encouraged the development of analytical techniques for its accurate determination. Spectrophotometric methods are those most frequently applied for iron determination in real samples, with specific reagents for the two existing oxidation state right now. In the present work, two low-cost, non-toxic, colorimetric reagents are proposed: deferiprone and kojic acid. These compounds present peculiar features, in particular the formation of 1:3 complexes with Fe3+ of extremely high stability and absorptivity in a wide operative pH range. In this study, we show that both reagents can be used to measure the total iron content. Actually, the extremely low redox potential characterizing the FeL3 complexes permits to determine the total concentration of iron independently from the starting oxidation state, and assures the complete oxidation in presence of oxygen of any amount of Fe2+ to Fe3+ complexes. These features constitute a novelty in the analytical determination of total iron not requiring any pretreatment of the sample, contrary to the methods in use, devoted either to Fe3+ or to Fe2+, necessitating awkward and error generating oxidative or reductive processes. The analytical performance of the proposed spectrophotometric method has been evaluated for the full compliance with the Lambert-Beer law, the operative range of iron concentration, the influence of pH, and the interfering effects of other metal ions. Finally, it has been validated in terms of LoD, LoQ, linearity, precision, and trueness, and has been tested on total iron determination in natural water certified material and in two biological reference materials, human urine and serum

Handwriting in primary school: comparing standardized tests and evaluating impact of grapho-motor parameters

A growing number of primary school students experience difficulties with grapho-motor skills involved in handwriting, which impact both form and content of their texts. Therefore, it is important to assess and monitor handwriting skills in primary school via standardized tests and detect specific grapho-motor parameters (GMPs) which impact handwriting legibility. Multiple standardized tools are available to assess grapho-motor skills in primary school, yet little is known on between-test agreement, on impact of specific GMPs on children's overall performance and on which GMPs may be specifically hard to tackle for children that are starting to consolidate their handwriting skills. These data would be extremely relevant for clinicians, therapists and educators, who have to choose among different assessment tools as well as design tailored intervention strategies to reach adequate performance on different GMPs in cases of poor handwriting. To gain better understanding of currently available standardized tools, we compared overall performance of 39 Italian primary school children (19 second graders and 20 third graders) experiencing difficulties with handwriting on three standardized tests for grapho-motor skills assessment and explored the impact of individual GMPs on child performance. Results showed some agreement between tests considering all children in our sample, but no agreement in second grade and only limited agreement in third grade. Data also allowed highlighting significant correlations between some GMP scores and children's overall performance in our sample. Finally, children in our sample appeared to experience specific difficulties with some GMPs, such as letter joins and alignment

As(III, V) Uptake from Nanostructured Iron Oxides and Oxyhydroxides: The Complex Interplay between Sorbent Surface Chemistry and Arsenic Equilibria

Iron oxides/oxyhydroxides, namely maghemite, iron oxide-silica composite, akaganeite, and ferrihydrite, are studied for AsV and AsIII removal from water in the pH range 2–8. All sorbents were characterized for their structural, morphological, textural, and surface charge properties. The same experimental conditions for the batch tests permitted a direct comparison among the sorbents, particularly between the oxyhydroxides, known to be among the most promising As-removers but hardly compared in the literature. The tests revealed akaganeite to perform better in the whole pH range for AsV (max 89 mg g−1 at pH0 3) but to be also efficient toward AsIII (max 91 mg g−1 at pH0 3– 8), for which the best sorbent was ferrihydrite (max 144 mg g−1 at pH0 8). Moreover, the study of the sorbents’ surface chemistry under contact with arsenic and arsenic-free solutions allowed the understanding of its role in the arsenic uptake through electrophoretic light scattering and pH measurements. Indeed, the sorbent’s ability to modify the starting pH was a crucial step in determining the removal of performances. The AsV initial concentration, contact time, ionic strength, and presence of competitors were also studied for akaganeite, the most promising remover, at pH0 3 and 8 to deepen the uptake mechanism

Comparison of the biotypes of Yersinia enterocolitica isolated from pigs, cattle and sheep at slaughter and from humans with yersiniosis in Great Britain during 1999-2000

Aims: To investigate the relationship between livestock carriage of Yersinia enterocolitica and human disease. The biotypes/serotypes of strains recovered from the faeces of pigs, cattle and sheep at slaughter during a national survey in Great Britain in 1999-2000, were compared with those of strains isolated from human cases of yersiniosis during the same period. Methods and Results: The faecal carriage of Y. enterocolitica by cattle, sheep and pigs at slaughter was 6.3, 10.7 and 26.1%, respectively. Yersinia enterocolitica biotype (BT) 1a was the most frequently isolated biotype from livestock (58%) and was the predominant biotype (53%) isolated from human cases over the same period. The main recognized pathogenic Y. enterocolitica biotype isolated from livestock was BT3 (O:5,27) (35% of sheep, 22% of pigs and 4% of cattle) but this biotype was not detected in any of the human isolates investigated. The major pathogenic biotypes of strains isolated from humans were BT3 (O:9) (24%) and BT4 (O:3) (19%) whereas of the veterinary isolates investigated, only pigs (11%) carried BT3 (O:9) strains. Conclusions: Because of significant overlaps in phenotypes of the veterinary and human strains it is not possible to comment on the correlation between host and pathogenicity, especially of biotype 1a. Significance and Impact of the Study: The data suggest that further investigations using methods with greater discriminatory power are required. However the data also suggests that pigs may be the primary reservoir for human pathogenic Y. enterocolitica infection

A family of kojic acid derivatives aimed to remediation of Pb2+ and Cd2+

The present work analyzes the complex formation ability towards Pb2+ and Cd2+ of a series of kojic acid derivatives that join the chelating properties of the pyrone molecules and those of polyamines, with the aim of evaluating how the different effects of oxygen and nitrogen coordinating groups act on the stability of metal complexes. Experimental research is carried out using potentiometric and spectrophotometric techniques supported by 1H and 13C NMR spectroscopy and DFT calculations. Actually, a different coordination mechanism toward Pb2+ and Cd2+ was proved: in the case of Pb2+, coordination takes place exclusively via the oxygen atoms, while the contribute of the nitrogen atoms appears relevant in the case of Cd2+. Lead complexes of all the studied ligands are characterized by significantly stronger stability than those of cadmium. Finally, on the basis of the measured complex formation stabilities, some of the proposed molecules seems promising effective ligands for lead and cadmium ion decorporation from polluted soils or waste waters

Acute stress symptoms in general population during the first wave of COVID lockdown in Italy: Results from the COMET trial

Background: The coronavirus disease of 2019 (COVID-19) pandemic is an unprecedented traumatic event that has severely impacted social, economic, and health well-being worldwide. The COvid Mental hEalth Trial was specifically designed to evaluate the impact of the COVID-19 pandemic and its containment measures on the mental health of the Italian general population in terms of COVID-19-related acute stress disorder (ASD) symptoms. Methods: The present cross-sectional study is based on an online survey carried out in the period March-May 2020. Italian general adult population was invited to compile an anonymous survey, which included the severity of acute stress symptoms scale/National Stressful Events Survey Short Scale to investigate the occurrence and severity of ASD symptoms. Results: The final sample consisted of 20,720 participants. During the lockdown, subjects with pre-existing mental health problems reported a statistically significant higher risk of acute post-traumatic symptoms compared to the general population (B: 2.57; 95% CI:2.04-3.09; p < .0001) and health care professionals (B: .37; 95% CI: .02-0.72; p < .05). According to multivariate regression models, the levels of acute post-traumatic symptoms (p < .0001) were higher in younger and female respondents. Social isolation and sleep disorder/insomnia represented positive predictors of acute stress (B = 3.32, 95% CI = 3.08-3.57). Conclusions: Concerns about the risk of infection as well as social isolation caused a higher incidence of acute post-traumatic stress symptoms that may predict the subsequent development of post-traumatic stress disorder symptoms in the long term

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO