Biomimetic bone apatite coatings were realized for the first time by the novel Ionized Jet Deposition technique. Bone coatings were deposited on titanium alloy substrates by pulsed electron ablation of deproteinized bovine bone shafts in order to resemble bone apatite as closely as possible. The composition, morphology and mechanical properties of the coatings were characterized by GI-XRD, FT-IR, SEM-EDS, AFM, contact angle measurements, micro-scratch and screw-insertion tests. Different post-treatment annealing conditions (from 350°C to 425°C) were investigated. Bone apatite coatings exhibited a nanostructured surface morphology and a composition closely resembling that of the deposition target (i.e. natural bone apatite), also regarding the presence of magnesium and sodium ions. Crystallinity and composition of the coatings were strongly influenced by annealing temperature and duration; in particular, upon annealing at 400°C and above, a crystallinity similar to that of bone was achieved. Finally, adhesion to the titanium substrate and hydrophilicity were significantly enhanced upon annealing, all characteristics being known to have a strong positive impact on promoting host cells attachment, proliferation and differentiation. 2− , Sr + , K + , etc.) [14,15]. In turn, suitable ion release can trigger stem cells homing and their osteogenic differentiation commitment, thus

PurposeThis paper explores digital transformation's impact on the work of owners in entrepreneurial firms. The interplay between working practices and technology is analyzed, taking into account the organizations' specific contexts.Design/methodology/approachA multiple case study design was applied. Eight cases of entrepreneurial firms, defined as companies that bring new products and services to the market by creating and seizing opportunities, were selected, with the goal to maximize the diversity of cases. The sample includes both small- and medium-sized firms, as well as high- tech and low- tech companies in equal number. Interviews have been used to collect both quantitative and qualitative data, which was analyzed in a structured way.FindingsThe digital transformation of entrepreneurial work, that is the daily work of entrepreneurs, is an evolutionary, practice-based phenomenon, rather than the result of rational design. The use of different digital tools is interrelated and depends on the characteristics, and dynamics of the surrounding environment.Practical implicationsThe findings of this study are relevant to entrepreneurs interested in understanding the dynamics of their working practice, to software development firms interested in entrepreneurs as customers and to institutions interested in the education of entrepreneurs.Originality/valueTo the best of the authors' knowledge this is the first study which considers the interplay between digital technology and the daily activities of entrepreneurs, considered as a whole. It provides insights on how these interconnected dimensions evolve, thus contributing to understanding the work of entrepreneurs, and as a consequence the dynamics of entrepreneurial firms in the context of digital transformation of organizations.

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Bone grafts and bone-based materials are widely used in orthopedic surgery. However, the selection of the bone type to be used is more focused on the biological properties of bone sources than physico-chemical ones. Moreover, although biogenic sources are increasingly used for deposition of biomimetic nanostructured coatings, the influence of specific precursors used on coating’s morphology and composition has not yet been explored. Therefore, in order to fill this gap, we provided a detailed characterization of the properties of the mineral phase of the most used bone sources for allografts, xenografts and coating deposition protocols, not currently available. To this aim, several bone apatite precursors are compared in terms of composition and morphology. Significant differences are assessed for the magnesium content between female and male human donors, and in terms of Ca/P ratio, magnesium content and carbonate substitution between human bone and different animal bone sources. Prospectively, based on these data, bone from different sources can be used to obtain bone grafts having slightly different properties, depending on the clinical need. Likewise, the suitability of coating-based biomimetic films for specific clinical musculoskeletal application may depend on the type of apatite precursor used, being differently able to tune surface morphology and nanostructuration, as shown in the proof of concepts of thin film manufacturing here presented.

The purpose of this paper is to analyze the energy innovative start-ups currently existing in Italy. An investigation on whether those firms are able to implement a knowledge-based strategy (KS) is described: In particular, it is a strategy based on a high investment in qualified human resources and, in general, this is reflected in the fact that the company adopting a KS pays its employees more than the average of other companies belonging to the same sector. Furthermore the ability to generate a return on the investment in knowledge is analyzed. A methodology already proposed in other papers by the same authors was applied in order to identify firms that adopt a KS understanding also the sustainability of such kind of strategy. A discussion on how firms that do not implement a profitable KS can improve and consolidate their position in terms of knowledge is proposed.