374 research outputs found

    Psychometric Properties of the Oldenburg Burnout Inventory in a Portuguese Sample of Aircraft Maintenance Technicians

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    Funding: PhD fellowship - PP - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Grant/Award, Number: 88887150178/2017-00.From its initial conceptualization as emotional exhaustion, cynicism, and reduced personal efficacy for the help professions, burnout has received increasing attention in modern times, especially after the 2019 WHO’s inclusion of this syndrome in the ICD-11 list. Burnout can be measured using several psychometric instruments that range in dimensionality, number of items, copyrighted, and free use formats. Here, we report the psychometric properties of data gathered with the Oldenburg Burnout Inventory (OLBI) in a sample of Portuguese Aircraft maintenance technicians. As far as we know, this is the first study addressing the burnout syndrome in this occupational group. Data gathered with the OLBI displayed good evidence of validity related to internal structure, to other variables, with good evidence of reliability. We showed that burnout significantly correlated with mental and physical fatigue emphasizing the vital critical role that these variables play with safety in the aviation industry.publishersversionpublishe

    Fluorescent Nanocrystals Reveal Regulated Portals of Entry into and Between the Cells of Hydra

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    Initially viewed as innovative carriers for biomedical applications, with unique photophysical properties and great versatility to be decorated at their surface with suitable molecules, nanoparticles can also play active roles in mediating biological effects, suggesting the need to deeply investigate the mechanisms underlying cell-nanoparticle interaction and to identify the molecular players. Here we show that the cell uptake of fluorescent CdSe/CdS quantum rods (QRs) by Hydra vulgaris, a simple model organism at the base of metazoan evolution, can be tuned by modifying nanoparticle surface charge. At acidic pH, amino-PEG coated QRs, showing positive surface charge, are actively internalized by tentacle and body ectodermal cells, while negatively charged nanoparticles are not uptaken. In order to identify the molecular factors underlying QR uptake at acidic pH, we provide functional evidence of annexins involvement and explain the QR uptake as the combined result of QR positive charge and annexin membrane insertion. Moreover, tracking QR labelled cells during development and regeneration allowed us to uncover novel intercellular trafficking and cell dynamics underlying the remarkable plasticity of this ancient organism

    Star poly(ε-caprolactone)-based electrospun fibers as biocompatible scaffold for doxorubicin with prolonged drug release activity

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    Abstract In this work, a novel drug delivery system consisting of poly(e-caprolactone) (PCL) electrospun fibers containing an ad-hoc-synthesized star polymer made up of a poly(amido-amine) (PAMAM) core and PCL branches (PAMAM-PCL) was developed. The latter system which was synthesized via the ring opening polymerization of e-caprolactone, starting from a hydroxyl-terminated PAMAM dendrimer and characterized by means of 1H NMR, IR and DSC, was found to be compatible with both the polymer matrix and a hydrophilic chemotherapeutic drug, doxorubicin (DOXO), the model drug used in this work. The preparation of the dendritic PCL star product with an average arm length of 2000 g/mol was characterized using IR and 1H NMR measurements. The prepared star polymer possessed a higher crystallinity and a lower melting temperature than that of the used linear PCL. Electrospun fibers were prepared starting from solutions containing the neat PCL as well as the PCL/PAMAM-PCL mixture. Electrospinning conditions were optimized in order to obtain defect free fibers, which was proven by the structural FE-SEM study. PAMAM moieties enhanced the hydrophilicity of the fibers, as proved by comparing the water absorption for the PCL/PAMAM-PCL fibers to that neat PCL fibers. The drug-loaded system PCL/PAMAM-PCL was prepared by directly introducing DOXO into the electrospinning solutions. The DOXO-loaded PCL/PAMAM-PCL showed a prolonged release of the drug with respect to the DOXO-loaded PCL fibers and elicited effective controlled toxicity over A431 epidermoid carcinoma, HeLa cervical cancer cells and drug resistant MCF-7 breast cancer cells. On the contrary, the drug-free PCL/PAMAM-PCL scaffold demonstrated no toxic effects on human dermal fibroblasts, suggesting the biocompatibility of the proposed system which can be used in cellular scaffold applications

    Synthesis and biological assay of GSH functionalized fluorescent quantum dots for staining Hydra vulgaris

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    Quantum dots (QDs) have been used extensively as fluorescent markers in several studies on living cells. Here, we report the synthesis of conjugates based on glutathione (GSH) and QDs (GSH-QDs) and we prove how these functionalized fluorescent probes can be used for staining a freshwater invertebrate called Hydra vulgaris. GSH is known to promote Hydra feeding response by inducing mouth opening. We demonstrate that GSH-QDs as well are able to elicit biological activity in such an animal, which results in the fluorescent staining of Hydra. GSH-QDs, once they reach the gastric region, are internalized by endodermal cells. The efficiency of GSH-QD internalization increases significantly when nanoparticles are coadministrated with free GSH. We also compared the behavior of bare QDs to that of GSH-QDs both in the presence and in the absence of free GSH. The conclusions from these series of experiments point to the presence of GSH binding proteins in the endodermal cell layer and uncover a novel role played by glutathione in this organism

    Clickable polymer ligand-functionalized iron oxide nanocubes: A promising nanoplatform for 'local hot spots' magnetically triggered drug release

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    Exploiting the local heat on the surface of magnetic nanoparticles (MNPs) upon exposure to an alternating magnetic field (AMF) to cleave thermal labile bonds represents an interesting approach in the context of remotely triggered drug delivery. Here, taking advantages of a simple and scalable two-step ligand exchange reaction, we have prepared iron oxide nanocubes (IONCs) functionalized with a novel multifunctional polymer ligand having multiple catechol moieties, furfuryl pendants, and polyethylene glycol (PEG) side chains. Catechol groups ensure a strong binding of the polymer ligands to the IONCs surface, while the PEG chains provide good colloidal stability to the polymer-coated IONCs. More importantly, furfuryl pendants on the polymer enable to click the molecules of interest (either maleimide–fluorescein or maleimide–doxorubicin) via a thermal labile Diels–Alder adduct. The resulting IONCs functionalized with a fluorescein/doxorubicin-conjugated polymer ligand exhibit good colloidal stability in buffer saline and serum solution along with outstanding heating performance in aqueous solution or even in viscous media (81% glycerol/water) when exposed to the AMF of clinical use. The release of conjugated bioactive molecules such as fluorescein and doxorubicin could be boosted by applying AMF conditions of clinical use (16 kAm–1 and 110 kHz). It is remarkable that the magnetic hyperthermia-mediated release of the dye/drug falls in the concentration range 1.0–5.0 μM at an IONCs dose as low as 0.5 gFe/L and at no macroscopical temperature change. This local release effect makes this magnetic nanoplatform a potential tool for drug delivery with remote magnetic hyperthermia actuation and with a dose-independent action of MNPs.This work was partially supported by the Marie Sklodowska-Curie Innovative training network MSCA-ITN-ETN (HeatNMof project, GA 860942), partially by the AIRC Foundation (AIRC IG-14527 to T.P.), partially by the European Research Council (starting grant ICARO, Contract No. 678109), and partially by ERC proof of concept Hypercube, Contract No. 899661)

    Effectiveness of combined extracorporeal shock-wave therapy and hyaluronic acid injections for patients with shoulder pain due to rotator cuff tendinopathy: a person-centered approach with a focus on gender differences to treatment response

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    Background Rotator cuff (RC) tendinopathy is a common shoulder pain condition. Extracorporeal shockwave therapy (ESWT) and hyaluronic acid peritendinous injection are viable treatment options for RC tendinopathy. The aim of this study is to evaluate the response in two different therapeutic rehabilitative approaches, the combined treatment ESWT plus hyaluronic acid injections (E + Hy) compared to ESWT alone (ESWT-al), in a cohort of patients with RC tendinopathy according to gender differences. Methods This is a retrospective longitudinal cohort study of patients with painful RC tendinopathy. Patients that had received a clinical evaluation, a shoulder ultra sound examination, as well as the Shoulder Pain and Disability Index (SPADI) questionnaire, and the Numerical Rating Scale (NRS) for pain at baseline, 1-month (T1) and 2-month follow-ups (T2) were included. Results Medical records of 53 patients were analyzed. In the comparison between baseline to T1 and similarly from baseline to T2, a statistically significant reduction has been reported in the NRS (p < 0.001) and in the SPADI (p < 0.001) in the entire study group. At T1, patients in the E + Hy compared to ESWT-al group, showed a slight but statistically significant reductions in both NRS and SPADI score, while these changes were more evident at T2 (p < 0.001). Interestingly, a gender dimorphism in NRS and in SPADI was found, with female patients that apparently responded better to the combined E + Hy compared to ESWT-al approach. Conclusion This retrospective cohort study suggests that the combination of ESWT plus HyA injections seems to be more effective than ESWT alone in RC tendinopathy in both genders. Moreover, in ESWT alone treatment, male patients reported better outcomes compared to females. However, further randomized controlled trials should be structured to confirm and enforce these conclusions

    Bioconjugation of Rod-Shaped Fluorescent Nanocrystals for Efficient Targeted Cell Labeling

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    In the present work, we report a three-step approach for the functionalization of CdSe/CdS core/shell and CdSe/CdS/ZnS double-shell quantum rods (QRs) with either biotin or folic acid. We carried out an in vitro study on cultured cells and fixed tissue sections in which the biofunctionalized QRs were compared with the more traditional CdSe/ZnS quantum dots (QDs), which were also functionalized with either biotin or folic acid. The QR and the QD samples exhibited the same specificity toward the targeting cells. In addition, due to the enhanced photoluminescence of the QRs with respect to QDs, a lower amount of rods was required to image cells. In immuno-localization experiments on rat brain tissue sections, biotin-functionalized QRs have shown the typical protein localization patterns expected both for neuronal enolase NSE and actin, confirming the specificity of the interaction of QRs with avidin, and the feasibility of these materials as fluorescent probes in tissue staining. In this specific targeting study, we could assess via the MTT test, a cell viability assay, the lower toxicity of the CdSe/CdS/ZnS QRs with respect to CdSe/CdS QRs

    Magnetically triggered release of molecular cargo from iron oxide nanoparticle loaded microcapsules

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    Iron oxide nanocube-modified microcapsules as a platform for magnetically triggered molecular release

    Magnetic nanobeads decorated by thermo-responsive PNIPAM shell as medical platforms for the efficient delivery of doxorubicin to tumour cells

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    Medical nanoplatforms based on clusters of superparamagnetic nanoparticles decorated with a PNIPAM thermo-responsive shell have been synthesized and used as drug carriers for doxorubicin (DOXO), a common chemotherapeutic agent. The nanosystem here developed has a total diameter below 200 nm and exploits the temperature responsive behaviour of the PNIPAM polymeric shell for the controlled loading and release of DOXO. The system has been tested in vitro on tumour cells and it clearly demonstrates the effectiveness of drug polymer encapsulation and time-dependent cell death induced by the doxorubicin release. Comparative cellular studies of the DOXO loaded nanoplatform in the presence or absence of an external magnet (0.3 T) showed the synergic effect of accumulation and enhanced toxicity of the system, when magnetically guided, resulting in the enhanced efficacy of the system

    Multifunctional nanostructures based on inorganic nanoparticles and oligothiophenes and their exploitation for cellular studies.

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    The combination of materials that possess different properties (such as, for instance, fluorescence and magnetism) into one single object of nanoscale size represents an attractive challenge for biotechnology, especially for their potential relevance in biomedical applications. We report here the preparation of novel bifunctional conjugates based on the linkage of inorganic nanoparticles to organic oligothiophene fluorophores (OTFs). In comparison to the organic dyes commonly used in bioimaging and more similarly to colloidal quantum dots, OTFs have broad optical absorption spectra, and therefore OTF fluorophores emitting at different colors can be excited with a single excitation source, allowing for easier multiplexing analysis. In this work we show the preparation of OTF-nanoparticle conjugates based on gold and iron oxide nanoparticles and their characterization using different techniques such as gel electrophoresis, photoluminescence spectroscopy, dynamic light scattering, and so on. In addition, by performing an in vitro study on human tumor cells we show that OTF-nanoparticle conjugates emitting at different colors can be used for multiplexing detection. Also, in the case of iron oxide-OTF conjugates, once uptaken by the cells, we show that they preserve both their fluorescent and their magnetic properties
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