Development and characterisation of microporous biomimetic scaffolds loaded with magnetic nanoparticles as bone repairing material

Fine-tuning of the scaffolds structural features for bone tissue engineering can be an efficient approach to regulate the specific response of the osteoblasts. Here, we loaded magnetic nanoparticles aka superparamagnetic iron oxide nanoparticles (SPIONs) into 3D composite scaffolds based on biological macromolecules (chitosan, collagen, hyaluronic acid) and calcium phosphates for potential applications in bone regeneration, using a biomimetic approach. We assessed the effects of organic (chitosan/collagen/hyaluronic acid) and inorganic (calcium phosphates, SPIONs) phase over the final features of the magnetic scaffolds (MS). Mechanical properties, magnetic susceptibility and biological fluids retention are strongly dependent on the final composition of MS and within the recommended range for application in bone regeneration. The MS architecture/pore size can be made bespoken through changes of the final organic/inorganic ratio. The scaffolds undertake mild degradation as the presence of inorganic components hinders the enzyme catalytic activity. In vitro studies indicated that osteoblasts (SaOS-2) on MS9 had similar cell behaviour activity in comparison with the TCP control. In vivo data showed an evident development of integration and resorption of the MS composites with low inflammation activity. Current findings suggest that the combination of SPIONs into 3D composite scaffolds can be a promising toolkit for bone regeneration.     

Random poly(ε‐caprolactone‐L‐alanine) by direct melt copolymerization

A series of random polyesteramides (PEAs) with a range of molar composition from 90/10 to 50/50 were synthesized by direct melt polycondensation of ε‐caprolactone and l ‐alanine. Their structure was fully characterized by Fourier transform IR and NMR spectroscopy. The resulting copolymers are completely amorphous with the exception of PEA‐90/10 which possesses a semicrystalline structure. These PEAs present increasing glass transition temperatures at increasing l ‐alanine contents and exhibit fairly good thermal stability with 10% mass loss temperatures reaching 315 °C. © 2020 Society of Industrial Chemistry     

Empirical study on Game Transfer Phenomena in a location-based augmented reality game

Research on Game Transfer Phenomena (GTP) has demonstrated that playing video games can lead to re-experiencing images, sounds, tactile sensations, spontaneous thoughts and actions, sometimes triggered by physical objects/events associated with the game. Location-based augmented reality games posit interesting questions regarding GTP, particularly because they use physical locations, they overlay digital images in physical contexts and the gameplay shifts between the virtual and the physical world. This study aims to investigate the prevalence of GTP and the role of immersion, augmented reality and sound in a sample of English- (EnS) and Spanish- (SpS) speaking gamers of the game Pokémon Go (PoGo). A total of 1313 gamers (M_age?=?31.47) were recruited online. GTP was less common than in previous studies; however, 82.4% had experienced GTP at least once. The SpS showed higher prevalence of GTP and played more intensively. Automatic mental processes predominated in the EnS, while behaviours and actions were more common in the SpS. The absence or presence of video game features seems important for the way GTP manifests. For instance, tactile hallucinations were more prevalent, while sensations of self-motion were less reported. Playing with augmented reality (AR) and sounds showed significant correlations with various GTP types, but not with re-experiencing images from the game. More gamers who reported the sensation that Pokémon were physically present or looked for Pokémon outside the screen while playing, as connotations of immersion, had experienced GTP. Experiencing GTP while playing may be more common in location-based augmented reality games, compared to other games.     

Indoor levels of volatile organic compounds at Florentine museum environments in Italy

Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts.     

Spatial choice behaviour: logit models and neural network analysis

Neural networks are becoming popular analysis tools in spatial research, as is witnessed by various applications in recent years. The performance of neural network analysis needs to be carefully judged, however, since the theoretical underpinning of neuro-computing is still weakly enveloped. In the present paper we will use the logit model as a benchmark for evaluating the result of neural network models, based on an empirical case study from Italy. The present paper aims to assess the foreseeable impact of the high-speed train in Italy, by investigating competition effects between rail and road transport modes. Two statistical models will then be compared, viz. the traditional logit model and a new technique for information processing, viz. the feedforward neural network model. In the study two different cases – corresponding to a different set of attributes – are investigated, namely by using only ‘time’ attributes and by using both ‘time’ and ‘cost’ attributes. From an economic viewpoint, both models appear to highlight the advantage of introducing the high-speed train system in that they show high probabilities of choosing the improved rail transport mode. The feedforward neural net model seems to provide reasonable predictions compared to those obtained by means of a logit model. An important lesson however, is that it is important to define properly the neural network architecture and to train sufficiently the network during the learning phase. Received: June 1996 / Accepted: February 1997     

Synthesis,structural and morphological characteristics,magnetic and optical properties of Co doped ZnO nanoparticles

Zn_1−xCo_xO (x==0.05, 0.10, 0.15) nanoparticles have been synthesized by an alternative wet-chemical synthesis route using the SimAdd technique. The as-obtained powders were investigated by FT-IR spectroscopy, X-ray diffraction and thermal analysis correlated with evolved gas analysis (TG–DTA–FT-IR) in order to determine their chemical nature, crystalline structure and to establish the decomposition sequences. The precipitates are generally amorphous, but low-intensity reflection peaks assigned both to the zinc oxalate dihydrate, and zinc hydroxide can be observed in the recorded patterns, indicating that hydroxy-oxalate precipitates were obtained. The structure, morphology and magnetic properties of the thermally treated samples have been investigated by X-ray diffraction, FT-IR, HRTEM, SAED, UV–vis and EPR. XRD studies reveal a hexagonal wurtzite-type structure for all Zn_1−xCo_xO samples. TEM investigations show particle size between 28 and 37 nm, with spherical and polyhedral shapes and with tendency to form aggregates. The presence of a Co₃O₄ secondary phase was evidenced by XRD, UV–vis and EPR for the Zn_0.85Co_0.15O sample. The ferromagnetic behavior of the samples was revealed. The paper highlights that by varying the cobalt concentration it is possible to modulate the structural, morphological, optical and magnetic properties.     

Synthesis of Invar 36 type alloys from elemental and prealloyed powders by mechanical alloying

Invar 36 (Fe₆₄Ni₃₆) nanocrystalline powders were successfully obtained by the mechanical alloying process. The mechanically alloyed Invar 36 powders were obtained from both, Fe–Ni elemental and Fe–Ni₃Fe prealloyed powders. XRD, DSC and magnetic measurements were used to characterise the Invar 36 powders. The lattice parameter evolution versus temperature of Invar 36 powders was investigated by in-situ high-temperature X-ray diffraction (HT-XRD). For both, Invar 36 (Fe, Ni) and Invar 36 (Fe, Ni₃Fe) powders, the lattice parameter values are constant up to about 350°C. The magnetic measurement also indicated that the Invar 36-type alloys are formed after 16?h of milling.     

Capillary rise properties of porous mullite ceramics prepared by an extrusion method with various diameters of fiber pore formers

Porous mullite ceramics with unidirectionally oriented pores were prepared by an extrusion method using rayon fibers as the pore formers. Rayon fibers of 8.1, 9.6, 16.8, and 37.6 μm in diameter were used as the pore formers and were kneaded with alumina powder, kaolin clay, China earthen clay, and water to form pastes. These pastes were extruded into cylindrical tubes, dried, and fired at 1500 °C for 4 h. The apparent porosities ranged from 45.7 to 48.2 %. The pore size distributions showed a sharp peak at 9.4, 10.0, 15.6, and 30 μm with increasing fiber diameters. The height of the capillary rise was 1780, 1670, 1320, and 950 mm with increasing fiber diameter. The maximum capillary rise is much higher than previously reported. The contact angle and effective pore radius that determine the capillary rise ability were calculated by fitting the capillary rise curves using the Fries and Dreyer’s equation.