Fracture behavior of concretes containing MSWI vitrified bottom ash

The incorporation of waste materials into concrete allows responding to some of the most significant issues of our society: waste management and climate change. Experimental studies carried out in last decades have shown that municipal solid waste incineration (MSWI) ash, and particularly bottom ash, which constitutes the major solid by-product of incineration process, can be adopted to produce building materials. However, several issues are related to the safety and the environmental impact of MSWI ash utilization for concrete production, mainly linked with the leaching of heavy metals and toxic organic components. To solve these problems, several treatments for MSWI ash can be adopted and, among them, in this work the attention was focused on vitrification technology, which enables to convert the ash in a glassy inert solid material. The aim of the present paper is to study the feasibility of developing a “green concrete” that incorporates vitrified MSWI bottom ash as partial cement replacement, so reducing the cement content and consequently the carbon dioxide emissions as well as the raw materials consumption related to its production. The vitrified MSWI bottom ash, ground at micrometer size, was inserted into the admixtures by considering two percentages of cement substitution (10% and 20% by weight of cement). The flexural behavior of concrete containing vitrified MSWI ash was investigated through three-point bending tests under crack mouth opening displacement control. The crack path evolution was further explored by adopting the Digital Image Correlation technique. By analyzing the obtained results, it can be concluded that the use into concrete of vitrified MSWI bottom ash as cement replacement up to a percentage of 20% by weight of cement, allows reaching comparable flexural resistances with respect to the reference concrete. So, the proposed approach can represent a viable solution for the development of environmental-friendly concretes able to reduce the environmental impact of the concrete industry, which is mostly related to cement production, as known

Environmental and pathological factors affecting the hatching success of the two northernmost loggerhead sea turtle (Caretta caretta) nests

In recent years, the report of loggerhead sea turtle (Caretta caretta) Mediterranean nesting range has expanded together with new records of nests becoming northward on the Italian coastline of the Tyrrhenian and Adriatic seas. These areas are characterized by intensive human activities, such as tourism, fishery, and marine traffic, all possibly involved in the influence of the use of coastal habitat by marine species. These anthropic threats, in addition to the natural ones and the changing environmental characteristics of the beach, may influence the growth of microorganisms causing hatching failures. Among microorganisms, fungal infection by the genus Fusarium (Link, 1809) is considered one of the main causes of globally declining sea turtle populations. In summer 2021, the two northernmost worldwide loggerhead sea turtle nests were monitored along the Northern Adriatic coastline (Veneto, Italy). These first records may potentially candidate this area as suitable for a large part of the loggerhead turtle's life cycle and it could represent a minor sea turtle nesting area that, according to Prato and colleagues, remained unnoticed due to the lack of specific monitoring. Sea Turtle Egg Fusariosis (STEF) was deemed to have deeply compromised the hatching success of the northmost one. Climate change and anthropogenic impacts have been scored as one of the highest hazards to sea turtle health and could have played a role in the STEF development. Environmental changes, human activities, and emerging pathogens deserve the highest attention in terms of health research, and conservation management

Simvastatin and downstream inhibitors circumvent constitutive and stromal cell-induced resistance to doxorubicin in IGHV unmutated CLL cells

The immunoglobulin heavy-chain variable region (IGHV) mutational status is a strong determinant of remission duration in chronic lymphocytic leukemia (CLL). The aim of this work was to compare the multidrug resistance (MDR) signature of IGHV mutated and unmutated CLL cells, identifying biochemical and molecular targets potentially amenable to therapeutic intervention.We found that the mevalonate pathway-dependent Ras/ERK1-2 and RhoA/RhoA kinase signaling cascades, and the downstream HIF-1\u3b1/P-glycoprotein axis were more active in IGHV unmutated than in mutated cells, leading to a constitutive protection from doxorubicin-induced cytotoxicity. The constitutive MDR phenotype of IGHV unmutated cells was partially dependent on B cell receptor signaling, as shown by the inhibitory effect exerted by ibrutinib. Stromal cells further protected IGHV unmutated cells from doxorubicin by upregulating Ras/ERK1-2, RhoA/RhoA kinase, Akt, HIF-1\u3b1 and P-glycoprotein activities. Mevalonate pathway inhibition with simvastatin abrogated these signaling pathways and reversed the resistance of IGHV unmutated cells to doxorubicin, also counteracting the protective effect exerted by stromal cells. Similar results were obtained via the targeted inhibition of the downstream molecules ERK1-2, RhoA kinase and HIF-1\u3b1.Therefore, targeting the mevalonate pathway and its downstream signaling cascades is a promising strategy to circumvent the MDR signature of IGHV unmutated CLL cells

Combined effects of biochar and recycled plastic aggregates on mechanical behavior of concrete

Only in Europe, every year around 29 million tons of plastic waste are generated and only about 35% of such waste is collected for recycling. This results in huge amounts of plastic waste threatening the environment. One of the possible solutions for disposal can be represented by the concrete industry. Several research works have already studied the use of plastic waste in concrete mix as partial replacement for aggregates, showing that this use of plastics can contribute to reducing the environmental impact of concrete production by saving non-renewable resources. At the same time, lightweight concrete can be produced but at a non-negligible cost of a mechanical strength reduction. This work aims at investigating the effects on concrete physical and mechanical performances resulting from the introduction of recycled plastic aggregates in combination with another kind of waste used as filler, namely biochar. Biochar, which is the solid carbonaceous by-product resulting from wood-waste pyro-gasification, can have the role of carbon sequestrating additive in concrete, being able to fix carbon in a stable form in buildings for decades. The experimental findings obtained in this work show that the combination of biochar and recycled plastic waste, which was never investigated before, can help to obtain concretes with satisfactory mechanical performance, which promote circular economy principles. Thanks to biochar addition, the reduction in mechanical properties due to the presence of plastics is extremely limited with respect to control; moreover, these concretes demonstrate better behavior in terms of fracture energy and ductility