Polyetheretherketone and titanium surface treatments to modify roughness and wettability-Improvement of bioactivity and antibacterial properties

Among the materials available for implant production,titanium is the most used while polyetherether-ketone (PEEK) is emerging thanks to its stability and to the mechanical properties similar to the ones of the bone tissue.Material surface properties like roughness and wettability play a paramount role in cell adhesion,cell proliferation,osteointegration and implant stability.Moreover,the bacterial adhesion to the biomaterial and the biofilm formation depend on surface smoothness and hydrophobicity.In this work,two different treatments,sandblasting and air plasma,were used to increase respectively roughness and wettability of two materials:titanium and PEEK.Their effects were analyzed with profilometry and contact angle measurements.The biological properties of the material surfaces were also investigated in terms of cell adhesion and proliferation of NIH-3T3 cells,MG63 cells and human Dental Pulp Stem Cells.Moreover,the ability of Staphylococcus aureus to adhere and form a viable biofilm on the samples was evaluated.The biological properties of both treatments and both materials were compared with samples of Synthegra(R) titanium,which underwent laser ablation to obtain a porous micropatterning,character-ized by a smooth surface to discourage bacterial adhesion.All cell types used were able to adhere and proliferate on samples of the tested materials.Cell adhesion was higher on sandblasted PEEK samples for both MG63 and NIH-3T3 cell lines,on the contrary,the highest proliferation rate was observed on sandblasted titanium and was only slightly dependent on wettability;hDPSCs were able to proliferate similarly on sandblasted samples of both tested materials.The highest osteoblast differentiation was ob-served on laser micropatterned titanium samples,but similar effects,even if limited,were also observed on both sandblasted materials and air plasma treated titanium.The lowest bacterial adhesion and biofilm formation was observed on micropatterned titanium samples whereas,the highest biofilm formation was detected on sandblasted PEEK samples,and in particular on samples not treated with air-plasma,which displayed the highest hydrophobicity.The results of this work showed that all the tested materials were able to sustain osteoblast adhesion and promote cell proliferation;moreover,this work highlights the fea-sible PEEK treatments which allow to obtain surface properties similar to those of titanium.The results here reported,clearly show that cell behavior depends on a complex combination of surface properties like wettability and roughness and material nature,and while a rough surface is optimal for cell adhesion,a smooth and less hydrophilic surface is the best choice to limit bacterial adhesion and biofilm formation.     

Combined Replenishment of miR‐34a and let‐7b by Targeted Nanoparticles Inhibits Tumor Growth in Neuroblastoma Preclinical Models

Neuroblastoma (NB) tumor substantially contributes to childhood cancer mortality. The design of novel drugs targeted to specific molecular alterations becomes mandatory, especially for high‐risk patients burdened by chemoresistant relapse. The dysregulated expression of MYCN, ALK, and LIN28B and the diminished levels of miR‐34a and let‐7b are oncogenic in NB. Due to the ability of miRNA‐mimics to recover the tumor suppression functions of miRNAs underexpressed into cancer cells, safe and efficient nanocarriers selectively targeted to NB cells and tested in clinically relevant mouse models are developed. The technology exploits the nucleic acids negative charges to build coated‐cationic liposomes, then functionalized with antibodies against GD₂ receptor. The replenishment of miR‐34a and let‐7b by NB‐targeted nanoparticles, individually and more powerfully in combination, significantly reduces cell division, proliferation, neoangiogenesis, tumor growth and burden, and induces apoptosis in orthotopic xenografts and improves mice survival in pseudometastatic models. These functional effects highlight a cooperative down‐modulation of MYCN and its down‐stream targets, ALK and LIN28B, exerted by miR‐34a and let‐7b that reactivate regulatory networks leading to a favorable therapeutic response. These findings demonstrate a promising therapeutic efficacy of miR‐34a and let‐7b combined replacement and support its clinical application as adjuvant therapy for high‐risk NB patients.     

Vitreoretinal Surgery in the Prevention and Treatment of Toxic Tumour Syndrome in Uveal Melanoma: A Systematic Review

Toxic tumour syndrome (TTS) is a particularly aggressive form of secondary vasculopathy occurring after radiation therapy of uveal melanoma due to the persistence of the necrotic tumour mass inside the eye. The development of TTS confers a particularly unfavourable functional and anatomical ocular prognosis, ultimately requiring enucleation in most cases if untreated. Vitreoretinal (VR) surgery has been successfully applied for treatment and prevention of TTS using both resecting and non-resecting techniques. In this systematic review, we aim to define characteristics of uveal melanomas benefiting the most from secondary VR surgery and to outline the optimal type and timing of VR intervention in such cases. Analysis of the literature reveals that endoresection should be performed within 3 months after radiotherapy to tumours thicker than 7 mm and with a largest basal diameter between 8 mm and 15 mm with post-equatorial location, especially after proton beam treatment. Alternatively, endodrainage remains a valid therapeutic option in eyes with macula-off retinal detachment, tumour diameter larger than 15 mm or ciliary body involvement. VR surgery can be successful in the management of TTS following radiotherapy for uveal melanoma when timing and indication are appropriately evaluated.     

The role of agroforestry networks in landscape socioeconomic processes: the potential and limits of the contingent valuation method

Agroforestry networks can be a means to achieve landscape amelioration. Some authorities of the Lagoon of Venice drainage basin (Italy) are planning, amongst other actions to control pollution in the Lagoon, to reintroduce agroforestry by means of a GIS-supported design procedure. The goals of this paper were to assess (i) the contingent valuation (CV) (willingness to pay and willingness to accept) of agroforestry networks and its relationship with socioeconomic and agroforestry role variables, (ii) the coherence between agro-economic policies and farmers expectations, (iii) the relationship between the value of agroforestry as a “shared good” and water quality (non-point source pollution). Respondents associate a positive value/preference to the agroforestry network implementation, although this value is strongly affected firstly by their identity with the landscape and secondly by their income. The motivations of farmers’ evaluation are precise and the agroforestry network is considered not only as an “ethical object” but also as a concrete element of their own cultural and economic world. In this case the contingent value (in particular, in terms of acceptance) increases with the farmer’s economic capacity, and the farmer’s valuation is not linked only to the “good” but also to the “service” offered for implementing it. The expectations of farmers regarding an agroforestry plantation were lower than European Union incentives at the time of survey, and a lack of results in this field is probably linked to poor information and to bureaucratic difficulties. Even if there is general knowledge on water quality, there is little awareness on the non-point source pollution control effect of agroforestry buffer plantations, either in the common people or in those who are environmentally trained (e.g. planning university students). In every case the agroforestry “shared good” evaluation is high enough to permit efficient and supported intervention policies. These results confirm that landscape choices strongly involve issues of identity, perceived rights and evaluation capacity that cannot be simply resolved in terms of preference cost benefit analyses, but a clever use of the CV allows an identification of these same limitations and a partial estimation of them.     

Role of bronchoalveolar lavage in predicting survival of patients with human immunodeficiency virus infection

In this multicenter study, we investigated the prognostic factors that influence the risk of death in patients with human immunodeficiency virus (HIV) infection. Clinical and laboratory indices obtained from 161 HIV-seropositive patients who underwent a detailed morphologic and immunophenotypic evaluation of bronchoalveolar lavage (BAL) and peripheral blood cell populations were retrospectively analyzed. In 155 patients, death occurred within the 48-mo follow-up (mean follow-up: 14.8 mo; range: 1 to 48 mo). In the univariate analysis, the patient's age (> 30 yr), HIV disease status, HIV transmission category, number of opportunistic pathogens isolated from the BAL, percentage of BAL neutrophils, and low number of BAL CD4 T cells were predictive of increased mortality. In contrast, the presence of an alveolitis or an increase in the numbers of alveolar macrophages and CD3 T cells was associated with a decreased mortality. In the multivariate analysis, significant independent predictors were age, risk factor for HIV, and presence of an alveolitis. Furthermore, patients with a low number of BAL CD4 T cells had a particularly poor prognosis while the CD4 T-cell count in the peripheral blood (< 50 cells/mm3 in the majority of our patients) had a negligible effect on predicting survival. Our findings suggest the clinical utility of BAL analysis in patients infected with HIV.     

The virtualization of human–robot interactions: a user-centric workload assessment

Virtual Reality - Interest in the virtualization of human–robot interactions is increasing, yet the impact that collaborating with either virtual or physical robots has on the human...     

Introducing HyPeak: An international network on hydropeaking research,practice, and policy

An increase in the demand for renewable energy is driving hydropower development and its integration with variable renewable energy sources. When hydropower is produced flexibly from hydropower plants, it causes rapid and frequent artificial flow fluctuations in rivers, a phenomenon known as hydropeaking. Hydropeaking and associated hydrological alterations cause multiple impacts on riverine habitats with cascading effects on ecosystem functioning and structure. Given the significance of its ecological and socio-economic implications, mitigation of hydropeaking requires an inter- and transdisciplinary approach. An interdisciplinary network called HyPeak has been conceived to enrich international research initiatives and support hydropower planning and policy. HyPeak has been founded based on exchange and networking activities linking scientists from several countries where hydropeaking has been widespread for decades and numerous studies dedicated to the topic have been carried out. HyPeak aims to integrate members from other countries and continents in which hydropower production plays a relevant role, and grow to be a reference group that provides expert advice on the topic to policy-makers, as well as researchers, stakeholders, and practitioners in the field of hydropeaking.     

Strategic cost and sustainability analyses of injection molding and material extrusion additive manufacturing

Economic and environmental costs are assessed for four different plastics manufacturing processes, including cold and hot runner molding as well as stock and upgraded material extrusion three dimensional (3D) printers. A larger stock 3D printer was found to provide a melting capacity of 14.4 ml/h, while a smaller printer with an upgraded extruder had a melting capacity of 36 ml/h. 3D printing at these maximum melting capacities resulted in specific energy consumption (SEC) of 16.5 and 5.28 kWh/kg, respectively, with the latter value being less than 50% of the lowest values reported in the literature. Even so, analysis of these respective processes found them to be only 2.9% and 3.8% efficient relative to their theoretical minimum energy requirements. By comparison, cold and hot runner molding with an all-electric machine had SEC of 1.28 and 0.929 kWh/kg, respectively, with efficiencies of 9.9% and 13.6% relative to the theoretical minima. Breakeven analysis considering the cost and carbon footprint of mold tooling found injection molding was preferable at a production quantity of around 70,000 units. Parametric analysis of model inputs indicates that the breakeven quantities are robust with respect to carbon tax incentives but highly dependent on mold costs, labor costs, and part size. Dimensional and mechanical properties of the molded and 3D printed specimens are also characterized and discussed.     

A Model-Based Framework to Optimize Pharmaceuticals Freeze Drying

This article is focused on the design of pharmaceutical freeze-drying recipes using in-line or off-line tools. In particular, the model predictive control system is here used to optimize the in-line process, and the design space is used for off-line optimization. Because both methods uses a mathematical model of the process, the problem of estimating the model parameters, including their uncertainty or variability in the lot of vials, is addressed. Then, the strengths and the weaknesses of the various methods are discussed, with particular emphasis on their robustness and their application in industrial-scale freeze dryers. In particular, the ability of the model predictive control tool to obtain the optimal recipe in only one run and its capacity to manage the system in case of an in-line modification of the product properties are shown. For this purpose, experimental results obtained for sucrose- and mannitol-based formulations are presented.     

Extraction kinetics of Fe(III) by di-(2-ethylhexyl) phosphoric acid using a Y–Y shaped microfluidic device

The extraction kinetics of Fe^III by di-(2-ethylhexyl) phosphoric acid (D2EHPA) were investigated using a Y–Y shaped microfluidic device. Finite-volume simulations were used to examine the accuracy of a single-step dimeric reaction mechanism in fitting the experimental data. Results demonstrate the validity of the proposed mechanism and show that Fe^III extraction occurred at a slow rate (second-order forward rate constant of k₁ = (3.0 ± 0.1) × 10⁻⁶ m⁴/mol s) under a mixed reaction–diffusion resistance regime. The present study provides insight for the control of Fe^III extraction rates in hydrometallurgical processes.