103 research outputs found

    Positive Psychological Capital as a Predictor of Satisfaction With the Fly-In Fly-Out Model

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    The flexibility of markets and international agreements have lured a growing number of companies to expand their business beyond frontiers in search for new markets and a bigger business network. Specifically, expatriates became keystones to implant and promote the so desired expansion into international markets, Particularly, Fly-in flyout (FIFO) flexpatriates. Although FIFO work practices are widely used, little is known about how to promote these professionals’ perceived job satisfaction (JS) across the course of their work cycles. That is why the goal of our research is to test the positive psychological capital (PsyCap) applicability to Portuguese FIFO flexpatriates. In the midst of the positive psychology theories, Luthans et al. (2007b) underline that workers are the psychological capital of any organization. Therefore, the development of the PsyCap becomes crucial and also contributes to the promotion of JS, nowadays a construct intertwined with well-being. As such, we developed and applied a HERO– (hope, self-efficacy, resilience, and optimism)–micro-intervention in order to assess whether it moderated the relationship between a FIFO flexpatriates PsyCap and their JS. The research took place over three distinct moments, both PsyCap and JS were measured before and after the HERO micro-intervention, and again 3 months later. The data collected shows that a positive correlation exists between FIFO flexpatriates PsyCap and JS. Moreover, our results pointed out that the micro-intervention enhanced FIFO flexpatriates PsyCap, and also showed that this increase lasted over (at least) 3 months.info:eu-repo/semantics/publishedVersio

    Polyester-based photocrosslinkable bioadhesives for wound closure and tissue regeneration support

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    Photocrosslinkable surgical adhesives provide many advantages when compared with traditional methods used in wound closure. This work aimed to develop UV-curable biodegradable adhesives based on lactic acid and PCL oligomers. Both materials were functionalized with 2-isocyanatoethyl acrylate (AOI). Subsequently, the photoinitiator (Irgacure® 2959) was added to the blend and then, the final materials were irradiated under UV light for two different times: 30 s and 2 min. After production of adhesives, its physicochemical properties were evaluated through FTIR-ATR and TGA, as well as its rheology, dynamic water contact angle, swelling capacity and hydrolytic degradation. Furthermore, the biocompatibility of the produced adhesives was also characterized in contact with human dermal fibroblasts cells. The antimicrobial activity of the materials was assessed by using Staphylococcus aureus and Escherichia coli, as bacterial models.info:eu-repo/semantics/publishedVersio

    Preparation of biodegradable functionalized polyesters aimed to be used as surgical adhesives

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    The study and development of new biocompatible materials to be applied as UV-curable adhesives is extremely important to grant the preparation of matrices with suitable mechanical, biological and thermal properties with a fast curing rate. Herein, photocrosslinkable biodegradable copolymers composed of unsaturated polyesters (UP) and lactic acid oligomers functionalized with 2-isocyanatoethyl methacrylate (IEMA) were produced. Henceforth, three different stoichiometric proportions were tested, which, after the addition of a biocompatible photoinitiator (Irgacure® 2959), resulted in flexible, resistant and uniform matrices after 2 minutes and 30 seconds of crosslinking. The synthesized materials were then further characterized in terms of chemical composition and thermal/mechanical behaviour. The gel content, dynamic contact angles, water sorption capacity and hydrolytic degradation were also assessed. The biocompatibility and antibacterial activity of the produced materials was also evaluated. Taking into account all the data obtained, it may be concluded that the new synthesized biodegradable bioadhesives present promising properties to be used as surgical adhesives.info:eu-repo/semantics/acceptedVersio

    Photocurable Polymeric Blends for Surgical Application

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    The preparation of photocrosslinkable bioadhesives synthesized from oligomers of lactic acid and polycaprolactone (PCL), both functionalized with 2-isocyanoethyl acrylate (AOI), were studied. The obtained modified macromers of LA-AOI (mLA) and PCL-AOI (mCL) were chemically characterized by 1H NMR and used to formulate polymeric blends with different mass proportions, 1:1, 1:2 and 2:1, respectively. Subsequently, the produced blends were crosslinked, considering two UV irradiation times: 30 and 120 s. After their production, the thermal and mechanical properties of bioadhesives were assessed, where upon the rheology, gel content, hydrolytic degradation and dynamic contact angles were determined. Furthermore, the cytotoxic profile of bioadhesives was evaluated in contact with human dermal fibroblasts cells, whereas their antibacterial effect was studied monitoring Escherichia coli and S. aureus growth. Overall, flexible and resistant films were obtained, presenting promising features to be used as surgical bioadhesives.info:eu-repo/semantics/publishedVersio

    Recent advances on antimicrobial wound dressing: A review

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    Skin and soft tissue infections (SSTIs) have high rates of morbidity and mortality associated. Despite the successful treatment of some SSTIs, those affecting the subcutaneous tissue, fascia, or muscle delay the healing process and can lead to life-threatening conditions. Therefore, more effective treatments are required to deal with such pathological situations. Recently, wound dressings loaded with antimicrobial agents emerged as viable options to reduce wound bacterial colonization and infection, in order to improve the healing process. In this review, an overview of the most prominent antibacterial agents incorporated in wound dressings along with their mode of action is provided. Furthermore, the recent advances in the therapeutic approaches used in the clinic and some future perspectives regarding antibacterial wound dressings are also discussed

    Oromucosal Alginate Films with Zein Nanoparticles as a Novel Delivery System for Digoxin

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    Digoxin is a hydrophobic drug used for the treatment of heart failure that possesses a narrow therapeutic index, which raises safety concerns for toxicity. This is of utmost relevance in specific populations, such as the elderly. This study aimed to demonstrate the potential of the sodium alginate films as buccal drug delivery system containing zein nanoparticles incorporated with digoxin to reduce the number of doses, facilitating the administration with a quick onset of action. The film was prepared using the solvent casting method, whereas nanoparticles by the nanoprecipitation method. The nanoparticles incorporated with digoxin (0.25 mg/mL) exhibited a mean size of 87.20 ± 0.88 nm, a polydispersity index of 0.23 ± 0.00, and a zeta potential of 21.23 ± 0.07 mV. Digoxin was successfully encapsulated into zein nanoparticles with an encapsulation efficiency of 91% (±0.00). Films with/without glycerol and with different concentrations of ethanol were produced. The sodium alginate (SA) films with 10% ethanol demonstrated good performance for swelling (maximum of 1474%) and mechanical properties, with a mean tensile strength of 0.40 ± 0.04 MPa and an elongation at break of 27.85% (±0.58), compatible with drug delivery application into the buccal mucosa. The current study suggests that SA films with digoxin-loaded zein nanoparticles can be an effective alternative to the dosage forms available on the market for digoxin administration

    Electrospun polymeric nanofibres as wound dressings: A review

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    Skin wounds have significant morbidity and mortality rates associated. This is explained by the limited effectiveness of the currently available treatments, which in some cases do not allow the reestablishment of the structure and functions of the damaged skin, leading to wound infection and dehydration. These drawbacks may have an impact on the healing process and ultimately prompt patients’ death. For this reason, researchers are currently developing new wound dressings that enhance skin regeneration. Among them, electrospun polymeric nanofibres have been regarded as promising tools for improving skin regeneration due to their structural similarity with the extracellular matrix of normal skin, capacity to promote cell growth and proliferation and bactericidal activity as well as suitability to deliver bioactive molecules to the wound site. In this review, an overview of the recent studies concerning the production and evaluation of electrospun polymeric nanofibrous membranes for skin regenerative purposes is provided. Moreover, the current challenges and future perspectives of electrospun nanofibrous membranes suitable for this biomedical application are highlighted

    Fatty acid composition, TLC screening, ATR-FTIR analysis, anti-cholinesterase activity, and in vitro cytotoxicity to A549 tumor cell line of extracts of 3 macroalgae collected in Madeira

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    Three macroalgae collected at Madeira Island were included in this study to determine their potential for drug, nutraceutical, food, or supplement application. Fatty acid content was higher in Zonaria tournefortii (12.32 mg g⁻¹ dw) with 16.58% of PUFAs, eicosapentaenoic acid (C20:5 omega 3), and arachidonic acid (20:4 omega 6) having concentrations of 2.59 and 1.17%, respectively. The anti-thrombogenic and anti-atherogenicity potential was higher for Z. tournefortii due to relevant fatty acids in the biochemical composition this macroalgae. Lipid classes were assessed in the lipid extract and neutral lipids (NL) were in higher yield in Asparagopsis taxiformis (51.16%) and lower in Z. tournefortii (26.96%). The glycolipids (GL) were between 36.03 and 16.11% in Z. tournefortii and Ulva lactuca. Phospholipids (PL) fraction varied from 35.91 and 31.60% in A. taxiformis and Z. tournefortii. TLC screening identified that U. lactuca contains phytol and cholesterol in its NL, digalactosyldiacylglycerol in its GL, and cardiolipin and L-alpha-phosphatidylcholine in its PL. Zonaria tournefortii contains phytol and cholesterol in its NL classes, and the PL classes contain L-alpha-phosphatidylethanolamine and 1-(3-sn-phosphatidyl)-rac-glycerol. The macroalgae A. taxiformis revealed cholesterol in its NL fraction and the same phospholipids as Z. tournefortii in its PL fraction. ATR-FTIR analysis enabled a "fingerprint" spectra and important sulfation absorption bands were identified, revealing the functional polysaccharides within these macroalgae. Anti-cholinesterasic activity was assessed in A. taxiformis, with a low IC50 for AChE (8.92 +/- 0.43 mu g mL⁻¹) and BuChE (13.96 +/- 0.32 mu g mL⁻¹), demonstrating dual inhibitory activity, justifying the interest to identify the active principle which may be the scaffold of a novel drug.This work was financially supported by DemoBlueAlgae “Desenvolvimento de metodologias e optimização dos processos de cultivo e processamento de macroalgas para a indústria e economia azul” PROCiência 2020 (M1420-01-0247-FEDER000002); MACBIOBLUE “Proyecto demostrativo y de transferencia tecnológica para ayudar a las empresas a desarrollar nuevos produtos y procesos en el ambito de la Biotecnología Azul de la Macaronesia” (MAC/1.1b/ 086), program Interreg MAC 2014–2020; ARDITI - Regional Agency for the Development of Research Technology and Innovation (M14-20-09-5369-FSE-000001-Doctorate in Business; Blue Iodine II “Boost Blue economy through market uptake an innovative seaweed bioextract for iodine fortification II”, grant agreement no. 733552, H2020-SMEInst-2016-2017.info:eu-repo/semantics/publishedVersio

    Antioxidant mechanisms to counteract TiO2-nanoparticles toxicity in wheat leaves and roots are organ dependent

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    Nanoparticles (NP) bioactivity is under deep scrutiny. In this work, the antioxidant response to TiO2-NP in wheat (Triticum aestivum) was determined. For that, enzymatic and the non-enzymatic antioxidants were evaluated in plants exposed to the P25 anatase:rutile material composed of TiO2-NP and under environmentally realistic doses (0; 5; 50; 150 mg/L for 20 days). Shoot but not root growth was reduced. In leaves, thiol metabolism and ascorbate accumulation were the preferred route whereas in roots the pre-existing antioxidant capacity was preferentially utilized. Both leaves and roots showed increased glutathione reductase and dehydroascorbate reductase activities and decreased ascorbate peroxidase activity. Roots, nevertheless, presented higher enzymatic basal levels than leaves. On the other hand, when examining non-enzymatic antioxidants, the ratio of reduced-to-oxidized glutathione (GSH/GSSG) increased in leaves and decreased in roots. Exposed leaves also presented higher total ascorbate accumulation compared to roots. TiO2-NP exposure down regulated, with more prominence in roots, antioxidant enzyme genes encoding catalase, ascorbate peroxidase, monodehydroascorbate reductase and dehydroascorbate reductase. In leaves, superoxide dismutase gene expression was increased. All data pinpoint to TiO2-NP toxicity above 5 mg/L, with aerial parts being more susceptible, which draws concerns on the safety doses for the use of these NPs in agricultural practices.publishe

    Xanthan Gum–Konjac Glucomannan Blend Hydrogel for Wound Healing

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    Hydrogels are considered to be the most ideal materials for the production of wound dressings since they display a three-dimensional structure that mimics the native extracellular matrix of skin as well as a high-water content, which confers a moist environment at the wound site. Until now, different polymers have been used, alone or blended, for the production of hydrogels aimed for this biomedical application. From the best of our knowledge, the application of a xanthan gum-konjac glucomannan blend has not been used for the production of wound dressings. Herein, a thermo-reversible hydrogel composed of xanthan gum-konjac glucomannan (at different concentrations (1% and 2% w/v) and ratios (50/50 and 60/40)) was produced and characterized. The obtained data emphasize the excellent physicochemical and biological properties of the produced hydrogels, which are suitable for their future application as wound dressings.info:eu-repo/semantics/publishedVersio
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