Fluorogenic hyaluronan nanogels for detection of micro- and nanoplastics in water

Environmental pollution from plastics is exponentially increasing due to human activities. While larger microplastics can be detected with various methods, retrieving micron-sized fragments and nanoplastics remains challenging. Yet, these smaller-sized plastics have been raising considerable toxicological concern. Here, we show that a poorly emissive hyaluronan functionalized with rhodamine B (HA–RB) adheres with high affinity to various microplastic surfaces, becoming brightly emissive. Micro- and nanoplastics (MNPs) can be successfully detected with size as small as the diffraction limit of confocal microscopy (ca. 250 nm). FLIM images show that the fluorescence lifetime of the dye moieties changes according to the plastics, making possible a discrimination of the nature of MNPs based on lifetime. HA–RB, compared to previous reports, eliminates false-positive results caused by formation of dye aggregates, resulting in a higher S/N ratio which allows the unequivocal detection of nano-sized fragments

A trial acoustic improvement in a lecture hall with MPP sound absorbers and FDTD acoustic simulations

Sound absorbing micro-perforated panels (MPPs) are being increasingly used because of their high quality in terms of hygiene, sustainability and durability. The present work investigates the feasibility and the performance of MPPs when used as an acoustic treatment in lecture rooms. With this purpose, three different micro-perforated steel specimens were first designed following existing predictive models and then physically manufactured through 3D additive metal printing. The specimens\u2019 acoustic behavior was analyzed with experimental measurements in single-layer and double-layer configurations. Then, the investigation was focused on the application of double-layer MPPs to the ceiling of an existing university lecture hall to enhance speech intelligibility. Numerical simulations were carried out using a full-spectrum wave-based method: a finite-difference time-domain (FDTD) code was chosen to better handle time-dependent signals as the verbal communication. The present work proposes a workflow to explore the suitability of a specific material to speech requirements. The measured specific impedance complex values allowed to derive the input data referred to MPPs in FDTD simulations. The outcomes of the process show the influence of the acoustic treatment in terms of reverberation time (T30 ) and sound clarity (C50 ). A systematic comparison with a standard geometrical acoustic (GA) technique is reported as well

Perfluorinated compounds (pfcs) in river waters of central Italy. Monthly variation and ecological risk assessment (era)

Perfluorinated compounds (PFCs) are a wide class of emerging pollutants. In this study, we applied the US EPA method 533 for the determination of 21 PFCs in river water samples. In particular, this method was used to investigate the presence of the target PFCs in six rivers in central Italy during a 4-month-long monitoring campaign. In 73% of the analyzed samples, at least some of the target PFCs were detected at concentrations higher than the limit of detection (LOD). The sum of the 21 target analytes ( n-ary sumation 21PFCs) ranged from 4.3 to 68.5 ng L-1, with the highest concentrations measured in the month of June, probably due to a minor river streamflow occurring in the warmer summer months. Considering the individual congeners, PFBA and PFPeA, followed by PFHxA and PFOA, were the predominantly detected compounds. Short- and medium-chain PFCs (C4-C9) prevail over the long-chain PFCs (C10-C18), likely due to the increased industrial use and the higher solubility of short-chain PFCs compared to long-chain PFCs. The ecological risk assessment, conducted by using the risk quotient method, highlighted that the risk for aquatic environments associated with PFBA, PFPeA, PFBS, PFHxA and PFOA was low or negligible. Only for PFOA, there was a medium level of risk in two rivers in the month of June. With regard to PFOS, 54% of the river water samples were classified as "high risk" for the aquatic environment. The remaining 46% of the samples were classified as "medium risk.

Cytokine storm and histopathological findings in 60 cases of COVID-19-related death: from viral load research to immunohistochemical quantification of major players IL-1\u3b2, IL-6, IL-15 and TNF-\u3b1

This study involves the histological analysis of samples taken during autopsies in cases of COVID-19 related death to evaluate the inflammatory cytokine response and the tissue localization of the virus in various organs. In all the selected cases, SARS-CoV-2 RT-PCR on swabs collected from the upper (nasopharynx and oropharynx) and/or the lower respiratory (trachea and primary bronchi) tracts were positive. Tissue localization of SARS-CoV-2 was detected using antibodies against the nucleoprotein and the spike protein. Overall, we tested the hypothesis that the overexpression of proinflammatory cytokines plays an important role in the development of COVID-19-associated pneumonia by estimating the expression of multiple cytokines (IL-1\u3b2, IL-6, IL-10, IL-15, TNF-\u3b1, and MCP-1), inflammatory cells (CD4, CD8, CD20, and CD45), and fibrinogen. Immunohistochemical staining showed that endothelial cells expressed IL-1\u3b2 in lung samples obtained from the COVID-19 group (p\u2009<\u20090.001). Similarly, alveolar capillary endothelial cells showed strong and diffuse immunoreactivity for IL-6 and IL-15 in the COVID-19 group (p\u2009<\u20090.001). TNF-\u3b1 showed a higher immunoreactivity in the COVID-19 group than in the control group (p\u2009<\u20090.001). CD8\u2009+\u2009T cells where more numerous in the lung samples obtained from the COVID-19 group (p\u2009<\u20090.001). Current evidence suggests that a cytokine storm is the major cause of acute respiratory distress syndrome (ARDS) and multiple organ failure and is consistently linked with fatal outcomes

Modelling of implantable sensor packaging based on biocompatible polymers

Implantable devices are being used for long term healthcare and human body physiological monitoring of specific parameters. PDMS (poly-dimethyl-siloxane) can be used either for sensor or for packaging of the same sensor in many applications, notably in laparoscopy and laparotomy as feeler pin in order to help surgeons to touch specific tissues and to get a response based on the nature of the touched tissue (softness). The need of calibrated pressure on a tissue arises when we are in presence particular pathologies or impairments as: cancer issues, high risk of aneurism for aorta and brain, probable haemorrhage in touching capillaries, and so forth. This paper presents a packaging modelling of a build nanosensor to be used in a human body for surgery exploration as laparoscopy and laparotomy. A nanosensor is first build for common application and adapted for implantable applications, and a packaging is studied. The designed sensor is implemented by considering PDMS as polymeric material

Management of the corpse with suspect, probable or confirmed COVID-19 respiratory infection \u2013 Italian interim recommendations for personnel potentially exposed to material from corpses, including body fluids, in morgue structures and during autopsy practice.

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Fluorogenic hyaluronan-based probe: characterization and use in advanced microscopy

Among all, the application of nanomaterials in biomedical research and most recently in the environmental one has opened the fields of nanomedicine and nanoremediation. Sensing methods based on fluorescence optical probe are generally requested for their selectivity, sensitivity. However, most imaging methods in literature rely on a fluorescent covalent labelling of the system. Therefore, the main aim of this project was to synthetise a biocompatible fluorogenic hyaluronan probe (HA) polymer functionalised with a rhomadine B (RB) moieties and study its behaviour as an optical probe with different materials with microscopy techniques. A derivatization of HA with RB (HA-RB) was successfully obtained providing a photophysical characterization showing a particular fluorescence mechanism of the probe. Firstly, we tested the interaction with different lab-grade micro and nanoplastics in water. Thanks to the peculiar photophysical behaviour of the probe nanoplastics can be detected with confocal microscopy and more interestingly their nature can be discriminated based on the fluorescence lifetime decay with FLIM microscopy. After, the interaction of a model plant derived metabolic enzyme GAPC1 undergoing oxidative-triggered aggregation was explored with the HA-RB. We highlighted the probe interaction with the protein even at early stage of the kinetic. Moreover, nanoparticle tracking analysis (NTA) experiment demonstrates that the probe is in fact able to interact with the small pre-aggregates in the early stage of the aggregation kinetic. Ultimately, we focused on the possibility to apply the probe in a super resolution microscopy technique, PALM, exploiting its aspecific interaction to characterize the surface topography of PTFE polydisperse microplastics. Optimal conditions were reached at high concentration of the probe (70 nM) where 0.5-5 nM is always advisable for this technique. Thanks to the polymeric nature and fluorescence mechanism of the probe, this technique was able to reveal features of PTFE surface under the diffraction limit (< 250 nm)

Static quenching upon adduct formation: a treatment without shortcuts and approximations

Luminescence quenching is a process exploited in transversal applications in science and technology and it has been studied for a long time. The luminescence quenching mechanisms are typically distinguished in dynamic (collisional) and static, which can require different quantitative treatments. This is particularly important \u2013 and finds broad and interdisciplinary application \u2013 when the static quenching is caused by the formation of an adduct between the luminophore \u2013 at the ground state \u2013 and the quencher. Due to its nature, this case should be treated starting from the well-known law of mass action although, in specific conditions, general equations can be conveniently reduced to simpler ones. A proper application of simplified equations, though, can be tricky, with frequent oversimplifications taking to severe errors in the interpretation of the photophysical data. This tutorial review aims to (i) identify the precise working conditions for the application of the simplified equations of static quenching and to (ii) provide general equations for broadest versatility and applicability. The latter equations can be used even beyond the sole case of pure quenching, i.e., in the cases of partial quenching and even luminescence turn-on. Finally, we illustrate different applications of the equations via a critical discussion of examples in the field of sensing, supramolecular chemistry and nanotechnology