Preliminary survey on the occurrence of microplastics in bivalve mollusks marketed in Apulian fish markets

Microplastics (MPs) are a relevant threat to food safety because they are ingested by humans through various foods. Bivalves are at high risk of microplastic contamination due to their filter-feeding mechanism and pose a risk to consumers as they are ingested whole. In this work, microplastics were detected, quantified, identified, and classified in samples of mussels (Mytilus galloprovincialis) and oysters (Crassostrea gigas) marketed in the Apulia region. The total number of plastic debris was 789 particles in the mussel samples and 270 particles in the oyster samples, with size ranging from 10 to 7350 µm. Fragments with size within the category of 5-500 µm were the predominant findings in both species, with blue as the predominant color in mussels and transparent in oysters; most of the debris was polyamide and nylon polymers in the mussels and chlorinated polypropylene in the oysters. These results show that mussel and oyster samples purchased at fish markets are contaminated with microplastics. The sources may be diverse and further studies are needed to assess the impact of the marketing stage on microplastic contamination in bivalves to better define the human risk assessment associated with microplastic exposure from bivalves consumption

Different molecular mechanisms causing 9p21 deletions in acute lymphoblastic leukemia of childhood

Deletion of chromosome 9p21 is a crucial event for the development of several cancers including acute lymphoblastic leukemia (ALL). Double strand breaks (DSBs) triggering 9p21 deletions in ALL have been reported to occur at a few defined sites by illegitimate action of the V(D)J recombination activating protein complex. We have cloned 23 breakpoint junctions for a total of 46 breakpoints in 17 childhood ALL (9 B- and 8 T-lineages) showing different size deletions at one or both homologous chromosomes 9 to investigate which particular sequences make the region susceptible to interstitial deletion. We found that half of 9p21 deletion breakpoints were mediated by ectopic V(D)J recombination mechanisms whereas the remaining half were associated to repeated sequences, including some with potential for non-B DNA structure formation. Other mechanisms, such as microhomology-mediated repair, that are common in other cancers, play only a very minor role in ALL. Nucleotide insertions at breakpoint junctions and microinversions flanking the breakpoints have been detected at 20/23 and 2/23 breakpoint junctions, respectively, both in the presence of recombination signal sequence (RSS)-like sequences and of other unspecific sequences. The majority of breakpoints were unique except for two cases, both T-ALL, showing identical deletions. Four of the 46 breakpoints coincide with those reported in other cases, thus confirming the presence of recurrent deletion hotspots. Among the six cases with heterozygous 9p deletions, we found that the remaining CDKN2A and CDKN2B alleles were hypermethylated at CpG islands

Occurrence and Characterization of Microplastics in Commercial Mussels (Mytilus galloprovincialis) from Apulia Region (Italy)

Microplastics are a ubiquitous pollutant whose spreading is a growing concern worldwide. They can pose a threat to food safety and consumer health as they are ingested through various foods. Bivalves are considered the most contaminated, as they filter large amounts of seawater and enter consumers’ diet ingested whole. The aim of this study was to detect, quantify, identify and classify microplastics in mussels (Mytilus galloprovincialis) marketed in fishery stores in Bari and its surroundings (Apulia, Italy). A total of 5077 particles were isolated from our samples, with an average value of 1.59 ± 0.95 MPs/g and 6.51 ± 4.32 MPs/individual. Blue fragments, sized 10–500 μm, were the prevalent findings; most of them belonged to Polyamide (PA) polymers. The results of this study help to show that mussels represent a source of microplastics for consumers and a direct risk to their health, even considering that they may contain many chemical compounds and microorganisms that may or may not be pathogenic to humans. Further research is needed to assess the role of commercialization in bivalve molluscs contamination

Cerium(IV) oxide modification by inclusion of a hetero-atom: A strategy for producing efficient and robust nano-catalysts for methanol carboxylation

Cerium(IV) oxide has been reported to catalyse the direct carboxylation of methanol to dimethylcarbonate, DMC. Nevertheless, the life of commercially available catalysts is quite short as after the first cycle the activity decreases and after a few cycles goes to zero. Noteworthy, no reports are in the literature about the stability of catalysts and their life. We have investigated the behaviour of catalysts and their deactivation using either surface techniques, such as XPS, or structural techniques, such as XRD. The reduction of Ce(IV) to Ce(III) and surface modification seem to be responsible for de-activation of the oxide. The results of a detailed study correlating the size and structure of particles to the activity of the catalysts are reported in this paper. In particular, pure commercial CeO(2) is compared, using High Throughput Experiments (HTE), with CeO(2) synthesised in our laboratory and with the latter loaded with Al or Fe at various concentrations. The hetero-metals have a different effect on the stabilization of the Ce-catalyst and on its activity. Al-loaded CeO(2) affords the most interesting results in terms of lifetime and activity. Therefore, the correlation of the structural properties of CeO(2) loaded with Al at a concentration variable between 3 and 40% to the activity in catalysis is discussed in detail. XPS and XRD data have been used for the characterization of the catalyst before and after a catalytic run. Pure synthesised CeO(2) and CeO(2) loaded with Al are able to maintain their activity for several cycles (apparent TON of several tens) or three days of operation without any treatment after recovery, with a much better performance than the commercial catalysts that, conversely, loose their activity after a few cycles. The size of the particles determines the activity of the catalyst and we show that particles having a size 15-60 nm are the most active, while particles sized micrometers are much less active