271 research outputs found

    Safety Compliance in a Sample of Italian Mechanical Companies: The Role of Knowledge and Safety Climate

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    The accident rate in the Italian mechanical sector is still too high, and evidence-based interventions to improve safety performance are essential. To better address this, our study contributes to the understanding of how to promote safety compliance through safe behaviours by using a sample of Italian mechanical workers (n = 109). Before and after scheduled safety training, intervention data on organizational factors, as well as on individual factors affecting safety-related behaviours, were collected. Particularly, data were collected using multiple sources, including self-perception questionnaires (to measure the safety climate among the management and colleagues and the safety attitude), paper and pencil tests (to measure safety knowledge), and observations by personnel with experience in observation tasks (to measure safety behaviours objectively). A model class of competing general linear models was built to determine which of the models was best suited for predicting safety-related behaviours. The results showed that both knowledge and the management’s safety climate effectively promoted safety compliance. Crucial implications for the effectiveness of active teaching methods, along with the need for continuous training and the prominent role of the management team members in giving, through their actions, further relevance to the need to respect rules and procedures, were revealed. Finally, practical implications for researchers, corporate decision makers, government agencies, and international bodies are discussed

    Main-chain water-soluble polyphosphoesters: multi-functional polymers as degradable PEG-alternatives for biomedical applications

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    Polyphosphoesters (PPEs) are a class of (bio)degradable polymers with high chemical versatility and functionality. In particular, water-soluble PPEs with the phosphoester group in the polymer backbone are currently discussed as a potential alternative to poly(ethylene glycol) (PEG). Ring-opening polymerization of typically 5-membered cyclic phosphoesters gives straightforward access to various well-defined PPEs. Several PPE candidates have proven their biocompatibility in vitro in terms of cytocompatibility, antifouling properties, “stealth effect”, degradability (hydrolytic and enzymatic), and some promising in vivo results in drug delivery vehicles. The possibility to control the properties with the appropriate tuning of the lateral chain makes PPEs especially appealing. This review summarizes recent developments of such PPEs for biomedical applications, e.g. in protein-polymer conjugates, hydrogels for tissue engineering, or nanocarriers for drug and gene delivery. We summarize the progress made over the years, highlighting the strengths and the shortcomings of PPEs for these applications to date. We critically evaluate the current state of the art, try to assess their potential and to predict future perspectives, shedding light on the pathway that needs to be followed to translate into clinics

    Effectiveness of occupational health and safety training. A systematic review with meta-analysis

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    Purpose This meta-analysis aims to verify the efficacy of occupational health and safety (OHS) training in terms of knowledge, attitude and beliefs, behavior and health. Design/methodology/approach The authors included studies published in English (2007–2014) selected from ten databases. Eligibility criteria were studies concerned with the effectiveness of OHS training for primary prevention of workplace injury; and studies focused on examined outcome related to OHS. Findings The selected studies (n = 28) highlighted a strong support for the effectiveness of training on worker OHS attitudes and beliefs and, to a lesser extent, on worker’s knowledge but only medium for behavior and small evidences for its effectiveness on health. Research limitations/implications Future research should more deeply investigate the efficacy on knowledge increase of trainings delivered by experts and researchers, applying different methods, in a small group; training delivered by peer and by researcher, applying different methods; and trained workers less than 29 years and more than 49 years old, considering that workers in these age groups are particularly vulnerable to fatalities. Practical implications Our study is a contribution for those they intend to grant effective training, in response to specific needs of OHS. The evidences presented could be considered a first step to identify the factors related to the efficacy of OHS training to plan adequate interventions. Social implications The OHS training is effective on the basis of the extent interventions are carried out for each specific learning outcome. Originality/value This meta-analysis suggested that classroom training, although the most used and studied, does not ever revealed itself very effective: it was not significant for outcomes in terms of knowledge and showed a decreasing efficacy for attitudes and beliefs, behaviors and health. It seemed that there was a distinction between interventions on knowledge, attitudes and beliefs, as opposed to behavioral interventions and health

    Audience effect on domestic dogs’ behavioural displays and facial expressions

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    In the present study we investigated the infuence of positive and negative arousal situations and the presence of an audience on dogs’ behavioural displays and facial expressions. We exposed dogs to positive anticipation, non-social frustration and social frustration evoking test sessions and measured pre and post-test salivary cortisol concentrations. Cortisol concentration did not increase during the tests and there was no diference in pre or post-test concentrations in the diferent test conditions, excluding a diferent level of arousal. Displacement behaviours of “looking away” and “snifng the environment” occurred more in the frustration-evoking situations compared to the positive anticipation and were correlated with cortisol concentrations. “Ears forward” occurred more in the positive anticipation condition compared to the frustration-evoking conditions, was positively infuenced by the presence of an audience, and negatively correlated to the pre-test cortisol concentrations, suggesting it may be a good indicator of dogs’ level of attention. “Ears fattener”, “blink”, “nose lick”, “tail wagging” and “whining” were associated with the presence of an audience but were not correlated to cortisol concentrations, suggesting a communicative component of these visual displays. These fndings are a frst step to systematically test which subtle cues could be considered communicative signals in domestic dogs

    Thermodynamic stability of myoglobin-poly(ethylene glycol) bioconjugates: A calorimetric study

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    PEGylated proteins are widely used for therapeutic applications, therefore a fundamental understanding of the conjugates’ structure and their behaviour in solution is essential to promote new developments in this field. In the present work, myoglobin-poly(ethylene glycol) conjugates were synthesized and studied by differential scanning calorimetry and UV–vis spectroscopy to obtain information on the bioconjugates’ thermodynamic stability, also focusing on PEG’s role on the solvent-protein surface interaction. The overall results of this study indicated a thermal destabilization of the protein that follows the extent of the bioconjugation without, however, compromising the native structure which remains functional. Moreover, the myoglobin PEGylation prevented the post-denaturation aggregation phenomena and enhanced the protein thermal reversibility. The thermodynamic interpretation of the data indicated that the bioconjugation influences the solvent-exposed protein surface difference between native and denatured state, contributing to the interpretation of the overall protein modification and functionality

    Thermodynamic Evaluation of the Interactions between Anticancer Pt(II) Complexes and Model Proteins

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    In this work, we have analysed the binding of the Pt(II) complexes ([PtCl(4′-phenyl-2,2′:6′,2″-terpyridine)](CF3SO3) (1), [PtI(4′-phenyl-2,2′:6′,2″-terpyridine)](CF3SO3) (2) and [PtCl(1,3-di(2-pyridyl)benzene) (3)] with selected model proteins (hen egg-white lysozyme, HEWL, and ribonuclease A, RNase A). Platinum coordination compounds are intensively studied to develop improved anticancer agents. In this regard, a critical issue is the possible role of Pt-protein interactions in their mechanisms of action. Multiple techniques such as differential scanning calorimetry (DSC), electrospray ionization mass spectrometry (ESI-MS) and UV-Vis absorbance titrations were used to enlighten the details of the binding to the different biosubstrates. On the one hand, it may be concluded that the affinity of 3 for the proteins is low. On the other hand, 1 and 2 strongly bind them, but with major binding mode differences when switching from HEWL to RNase A. Both 1 and 2 bind to HEWL with a non-specific (DSC) and non-covalent (ESI-MS) binding mode, dominated by a 1:1 binding stoichiometry (UV-Vis). ESI-MS data indicate a protein-driven chloride loss that does not convert into a covalent bond, likely due to the unfavourable complexes’ geometries and steric hindrance. This result, together with the significant changes of the absorbance profiles of the complex upon interaction, suggest an electrostatic binding mode supported by some stacking interaction of the aromatic ligand. Very differently, in the case of RNase A, slow formation of covalent adducts occurs (DSC, ESI-MS). The reactivity is higher for the iodo-compound 2, in agreement with iodine lability higher than chlorine

    A circular dichroism study of the protective role of polyphosphoesters polymer chains in polyphosphoester‐myoglobin conjugates

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    Protein-polymer conjugates are a blooming class of hybrid systems with high biomedical potential. Despite a plethora of papers on their biomedical properties, the physical–chemical characterization of many protein-polymer conjugates is missing. Here, we evaluated the thermal stability of a set of fully-degradable polyphosphoester-protein conjugates by variable temperature circular dichroism, a common but powerful technique. We extensively describe their thermodynamic stability in different environments (in physiological buffer or in presence of chemical denaturants, e.g., acid or urea), highlighting the protective role of the polymer in preserving the protein from denaturation. For the first time, we propose a simple but effective protocol to achieve useful information on these systems in vitro, useful to screen new samples in their early stages

    Investigation of the LCST-Thermoresponsive Behavior of Novel Oligo(Ethylene Glycol)-Modified Pentafluorostyrene Homopolymers

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    Amphiphilic tetrafluorostyrene monomers (EFS8) carrying in the para position an oligoethylene glycol chain containing 8 oxyethylenic units on average were synthesized and used for preparation via activator regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP) of the corresponding amphiphilic homopolymers (pEFS8-x) with different degrees of polymerization (x = 26 and 46). Combining light transmittance and nano-differential scanning calorimetry (n-DSC) measurements revealed that pEFS8-x homopolymers displayed a lower critical solution temperature (LCST) thermoresponsive behavior in water solutions. Moreover, n-DSC measurements revealed the presence in heating scans of a broad endothermic peak ascribable to the dehydration process of the polymer single chains (unimers) and their collapse into aggregates. Consistently, dynamic light scattering (DLS) measurements showed below the LCST the presence of small nanostructures with a hydrodynamic diameter size Dh of 6–7 nm, which collapsed into concentration-dependent larger multichain aggregates (Dh = 300–3000 nm) above LCST. Interestingly, n-DSC data showed that the unimer-aggregate transition was reversible up to a specific temperature (Trev) of each homopolymer, which in any case was higher than Tmax. When heating above Trev the transition was no longer reversible, causing the shift of Tonset and Tmax at lower values, thus suggesting an increase in hydrophobicity of the polymer systems associated with a temperature-dependent dehydration process

    Guidelines for a correct evaluation of deep eutectic solvents thermal stability

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    Deep eutectic solvents (DESs) are a class of versatile and green emerging materials. Despite the huge amounts of applications proposed in the last years, studies on their thermal stability are often missing. In this short review, we propose a guide for a correct evaluation of DES thermal stability, conducted mainly by dynamical thermogravimetry (TGA). We collected all the data reported in the literature on choline chloride (ChCl)-based DESs, as proof of concept to show the potentialities of the technique, highlighting all the parameters that need to be considered for a correct analysis, with particular attention to the possible sources of misleading interpretations (e.g. the adsorbed water, or the formation of undesired products during DES preparation). In many cases, the additional use of isothermal TGA, or TGA coupled with online techniques such as Fourier Infra-Red Spectroscopy or Mass Spectrometry, may help for the data interpretation. Besides, we summarize in a graph the degradation temperatures of many DESs and their precursors, intended as an operative guide to choosing the correct DES for different applications. The findings reported to date, highlight the potentialities of thermal analysis on DESs, as a powerful tool to obtain essential information on their applicability, and to implement the knowledge of their nanostructure from a molecular point of view
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