Experimental study aimed at highlighting warnings for proper design, construction and control of geocomposite-reinforced asphalt pavements

The proper use of interlayers in asphalt pavements can be an effective and economic option to enhance their service life. However, the presence of a foreign element at the interface should be properly taken into account during design, construction and control of reinforced pavements. Given this background, the present laboratory study investigated stiffness and interface bonding properties of reinforced asphalt systems in order to achieve fundamental information for a correct design as well as proper construction and control of reinforced pavements. To accomplish this objective, different composite reinforcements (grids/fabrics embedded in bituminous membranes) were studied as interlayers of double-layered systems prepared with both traditional and polymer-modified asphalt concretes. Dynamic flexural tests and static interface shear tests were carried out. Unreinforced reference systems was also studied for comparison purposes. Results confirmed the abovementioned warnings that will allow delineating some preliminary guidelines related to the use of reinforcements in pavements

Aesthetic and Mechanical Suitability of a Clear Synthetic Resin as a Unconventional Binder for Road Pavements

Current environmental awareness interests several aspects of civil engineering, including road construction. Indeed, new challenges related to environmental pollution and landscape preservation must be faced. In this sense, clear road pavement surfaces represent an effective technology aimed at guaranteeing environmental-friendly aesthetic pavements. The use of clear synthetic resin as a binder involves several benefits for the mitigation of in-service reached temperatures and the heat distribution within pavements (with appreciable effects on pavement mechanical performance too). The present paper illustrates an experimental study aimed at analysing the chromatic and mechanical properties of a clear synthetic resin and thus its suitability as a binder for road pavement mixes. Chromatic characteristics were assessed through digital image analysis at different aging conditions. A dynamic shear rheometer was used to evaluate the linear viscoelastic properties as well as fatigue and rutting potential of the binder in a wide range of temperatures and frequencies. A conventional 35/50 penetration grade bitumen was also investigated for comparison purposes. The clear resin exhibited limited changes in colour (darkening effects), mainly in the case of short-term aging. On the other hand, a low temperature-dependency of such a binder was observed up to 58\ub0C. Slightly increased aptitude to rutting at the higher temperatures was detected, even if it is worth noting that clear in-service mixtures would achieve lower temperatures than traditional "black" materials at a given environmental condition (air temperature, solar radiation, etc.). The resin also exhibited a softer behaviour, along with an enhanced fatigue resistance. Overall, the studied innovative binder showed promising results in view of its effective use in road paving

Steel slag as valuable aggregate in eco\u2013friendly mixtures for asphalt pavements

Research and application concerning the use of environmentally friendly materials and technologies in road pavements have reached high relevance mainly due to the increasing public consciousness addressed to environmental protection and preservation. In this sense, the possible use of steel slags for construction applications (including road pavements) has a strategic importance to convert a waste into a valuable resource, taking also into account that ferrous slag may have a lower potential to negatively impact the environment. The environmental sustainability of asphalt mixtures prepared with steel slags can be further enhanced adopting the so-called Warm Mix Asphalt (WMA) technology. In fact, WMA is an asphalt concrete modified with additives that can be produced and applied at lower temperatures than the traditional Hot Mix Asphalt (HMA), thus reducing energy consumption, gas and fume emissions. Given this background, the paper illustrates a part of a wide research study aimed at verifying the utilization feasibility of steel slags in warm asphalt concretes. In particular, midrange and high-service temperature properties as well as water susceptibility of warm mixtures containing steel slags were assessed in the laboratory. The warm modification was performed using a chemical tensoactive additive, whereas slags were taken from a metallurgical plant equipped with an electric arc furnace (EAF). A WMA prepared with only natural aggregates was also studied for comparison purpose. The performance characterization was carried out through both static and cyclic laboratory tests. The results mainly showed that asphalt mixtures prepared combining chemical warm technology and EAF steel slag aggregates demonstrate promising field applicability

Deletion of the mitochondria-shaping protein Opa1 during early thymocyte maturation impacts mature memory T cell metabolism

Optic atrophy 1 (OPA1), a mitochondria-shaping protein controlling cristae biogenesis and respiration, is required for memory T cell function, but whether it affects intrathymic T cell development is unknown. Here we show that OPA1 is necessary for thymocyte maturation at the double negative (DN)3 stage when rearrangement of the T cell receptor β (Tcrβ) locus occurs. By profiling mitochondrial function at different stages of thymocyte maturation, we find that DN3 cells rely on oxidative phosphorylation. Consistently, Opa1 deletion during early T cell development impairs respiration of DN3 cells and reduces their number. Opa1-deficient DN3 cells indeed display stronger TCR signaling and are more prone to cell death. The surviving Opa1-/- thymocytes that reach the periphery as mature T cells display an effector memory phenotype even in the absence of antigenic stimulation but are unable to generate metabolically fit long-term memory T cells. Thus, mitochondrial defects early during T cell development affect mature T cell function

Bone marrow-derived cells can acquire cardiac stem cells properties in damaged heart

Experimental data suggest that cell-based therapies may be useful for cardiac regeneration following ischaemic heart disease. Bone marrow (BM) cells have been reported to contribute to tissue repair after myocardial infarction (MI) by a variety of humoural and cellular mechanisms. However, there is no direct evidence, so far, that BM cells can generate cardiac stem cells (CSCs). To investigate whether BM cells contribute to repopulate the Kit+ CSCs pool, we transplanted BM cells from transgenic mice, expressing green fluorescent protein under the control of Kit regulatory elements, into wild-type irradiated recipients. Following haematological reconstitution and MI, CSCs were cultured from cardiac explants to generate 'cardiospheres', a microtissue normally originating in vitro from CSCs. These were all green fluorescent (i.e. BM derived) and contained cells capable of initiating differentiation into cells expressing the cardiac marker Nkx2.5. These findings indicate that, at least in conditions of local acute cardiac damage, BM cells can home into the heart and give rise to cells that share properties of resident Kit+ CSCs

Two-steps versus one-step solidification pathways of binary metallic nanodroplet

The solidification of AgCo, AgNi, and AgCu nanodroplets is studied by molecular dynamics simulations in the size range of 2-8 nm. All these systems tend to phase separate in the bulk solid with surface segregation of Ag. Despite these similarities, the simulations reveal clear differences in the solidification pathways. AgCo and AgNi already separate in the liquid phase, and they solidify in configurations close to equilibrium. They can show a two-step solidification process in which Co-/Ni-rich parts solidify at higher temperatures than the Ag-rich part. AgCu does not separate in the liquid and solidifies in one step, thereby remaining in a kinetically trapped state down to room temperature. The solidification mechanisms and the size dependence of the solidification temperatures are analyzed, finding qualitatively different behaviors in AgCo/AgNi compared to AgCu. These differences are rationalized by an analytical model

Trichobezoars in children: therapeutic complications

Trichobezoars are concretions formed by the accumulation of hair or fibers in the gastrointestinal tract, usually associated with underlying psychiatric disorders in females between 13 and 20 years old. Endoscopy, the gold standard for diagnosis, brings some additional advantages: sample taking, size reducing and, rarely, mass removal. This study shows that endoscopy can cause severe complications resulting in a surgical emergency

Trichobezoars in children: therapeutic complications

Trichobezoars are concretions formed by the accumulation of hair or fibers in the gastrointestinal tract, usually associated with underlying psychiatric disorders in females between 13 and 20 years old. Endoscopy, the gold standard for diagnosis, brings some additional advantages: sample taking, size reducing and, rarely, mass removal. This study shows that endoscopy can cause severe complications resulting in a surgical emergency

Near real time pump optimization and pressure management

[EN] Management of existing systems can be interpreted as sets of decisions to make regarding pumps and valves to create hydraulic conditions able to satisfy the demand without operational problems such as pressures lower or higher than the normative pressure values. However, among the large number of combinations, some of them manage to reduce energy consumption, by finding the best operating point for pumps, and also water losses, by finding the best operating point for pressure reducing valves (PRV). Several works may be found in the literature using recent and advanced optimization techniques to define pump and valve operation. However, the processing time to define operational rules is a limiting factor for real time decision-making. Taking into account the need to improve the models in terms of optimal rules to apply in near real-time operations, this work presents a hybrid model (simulator + optimizer) to find pump speeds and PRV set points, aiming at combining energy savings with pressure control while reducing water losses. PSO is applied as the main optimization algorithm, which can also work in cooperation with other bio-inspired concepts to deploy an effective and fast search algorithm. The results allow comparisons with other techniques and show the ability of PSO to find an optimal point of operationBrentan, BM.; Luvizotto, EJ.; Montalvo, I.; Izquierdo Sebastián, J.; Pérez García, R. (2017). Near real time pump optimization and pressure management. Procedia Engineering. 186:666-675. doi:10.1016/j.proeng.2017.06.248S66667518

Use of adipose derived stem cells in Treacher Collins syndrome

Objective: Treacher Collins syndrome (TCS) is a rare congenital disorder of craniofacial development. TCS occurs with an incidence of 1:50,000, and more than 60% of TCS cases have no previous family history and arise as the result of de novo mutations. The high rate of de novo mutations, together with the extreme variability in the degree to which individuals can be affected, makes the provision of genetic counseling extremely complicated. Consequently, every case of TCS is unique and needs to be assessed individually. Patients with TCS frequently undergo multiple reconstructive surgeries from birth through adulthood, which rarely are fully corrective in the long-term. The nascent field of regenerative medicine offers the promise to improve some of these treatments. In particular, structural fat grafting (SFG) seems to be a good strategy not only to restore the normal volume and contour of the face, but also to provide a source of adipose-derived stem cells (ADSCs) with a multilineage differentiation potential. In this work, we present genetical analyses of ADSC affected by TCS. Materials and methods: ADSCs from were analyzed for their stemness properties and shared many characteristics with those of a healthy subject. Screening of the genome of the TCS patient using array-Comparative Genomic Hybridization allowed us to identify some chromosomal imbalances that are probably associated with TCS. Results: We found that some alterations, involving the TIMELESS gene, were usually associated with embryonic stem cells. Conclusions: With the aim to improve the final results, we need to consider combining knowledge of genetic alterations and expression profiles as a fundamental step before starting with surgical procedures