Toluene Adsorption by Mesoporous Silicas with Different Textural Properties: A Model Study for VOCs Retention and Water Remediation

In this work, dierent mesoporous silicas were studied as potential sorbents for toluene, selected as a model molecule of aromatic organic fuel-based pollutants. Three siliceous materials with dierent textural and surface properties (i.e., fumed silica and mesoporous Santa Barbara Amorphous (SBA)-15 and Mobil Composition of matter (MCM)-41 materials) were considered and the eect of their physico-chemical properties on the toluene adsorption process was studied. In particular, FT-IR spectroscopy was used to qualitatively study the interactions between the toluene molecule and the surface of silicas, while volumetric adsorption analysis allowed the quantitative determination of the toluene adsorption capacity. The combined use of these techniques revealed that textural properties of the sorbents, primarily porosity, are the driving forces that control the adsorption process. Considering that, under real conditions of usage, the sorbents are soaked in water, their hydrothermal stability was also investigated and toluene adsorption by both the gas and aqueous phase on hydrothermally pre-treated samples was studied. The presence of ordered porosity, together with the dierent pore size distribution and the amount of silanol groups, strongly aected the adsorption process. In toluene adsorption from water, SBA-15 performed better than MCM-41

Effectiveness of occupational health and safety training. A systematic review with meta-analysis

Purpose This meta-analysis aims to verify the efficacy of occupational health and safety (OHS) training in terms of knowledge, attitude and beliefs, behavior and health. Design/methodology/approach The authors included studies published in English (2007–2014) selected from ten databases. Eligibility criteria were studies concerned with the effectiveness of OHS training for primary prevention of workplace injury; and studies focused on examined outcome related to OHS. Findings The selected studies (n = 28) highlighted a strong support for the effectiveness of training on worker OHS attitudes and beliefs and, to a lesser extent, on worker’s knowledge but only medium for behavior and small evidences for its effectiveness on health. Research limitations/implications Future research should more deeply investigate the efficacy on knowledge increase of trainings delivered by experts and researchers, applying different methods, in a small group; training delivered by peer and by researcher, applying different methods; and trained workers less than 29 years and more than 49 years old, considering that workers in these age groups are particularly vulnerable to fatalities. Practical implications Our study is a contribution for those they intend to grant effective training, in response to specific needs of OHS. The evidences presented could be considered a first step to identify the factors related to the efficacy of OHS training to plan adequate interventions. Social implications The OHS training is effective on the basis of the extent interventions are carried out for each specific learning outcome. Originality/value This meta-analysis suggested that classroom training, although the most used and studied, does not ever revealed itself very effective: it was not significant for outcomes in terms of knowledge and showed a decreasing efficacy for attitudes and beliefs, behaviors and health. It seemed that there was a distinction between interventions on knowledge, attitudes and beliefs, as opposed to behavioral interventions and health

Synthetic Saponite Clays as Additives for Reducing Aging Effects in PIM1 Membranes

Polymers of intrinsic microporosity represent one of the most promising polymeric materials for gas separation applications. Their very rigid and contorted backbone induces unusually high free volumes and high internal surface area, with high gas permeabilities and moderate ideal selectivity, especially for O2/ N2 and CO2/N2 pairs with values lying above Robeson's upper bound. However, the high FFV of PIM1 tends to be short-lived, soon collapsing to leave fewer transport pathways and reduce gas permeability. One way to tackle this problem is the addition of fillers within the polymeric matrix. Here we report the use of synthetic clays named saponites as fillers to slow down the physical aging of PIM1 membranes. Mixed matrix membranes (MMMs) based on two different saponite samples (one completely inorganic and one functionalized with a surfactant) have been obtained, and their permeation performances have been studied in the course of one year to explore physical aging effects over time. Without filler, PIM1 exhibits the classical aging behavior of polymers of intrinsic microporosity, namely, a progressive decline in gas permeation. On the contrary, with saponites, MMMs present a plateau after 1 week within the aging showing that the fillers slow down the aging of PIM1 membranes in the long term. After one year of aging, the total reduction for CO2 permeability for native PIM1 was 80%, whereas for the MMMs it was 53% and 59% for the inorganic and the functionalized saponite, respectively. Interactions between the fillers and the polymeric matrix in addition to aging effects have been also monitored through SS-NMR spectroscopy. The 13C spin 12lattice relaxation time (T1) measurements reveal that PIM1 chains intercalation between T 12O 12T lamellar sheets could be one of the mechanisms responsible for PIM1 slowing down aging. Chains confinement between lamellar sheets could play a significant role in reducing the densification of chains, while maintaining small free volumes

Hyper Cross-Linked Polymers as Additives for Preventing Aging of PIM-1 Membranes

Mixed-matrix membranes (MMMs) are membranes that are composed of polymers embedded with inorganic particles. By combining the polymers with the inorganic fillers, improvements can be made to the permeability compared to the pure polymer membranes due to new pathways for gas transport. However, the fillers, such as hyper cross-linked polymers (HCP), can also help to reduce the physical aging of the MMMs composed of a glassy polymer matrix. Here we report the synthesis of two novel HCP fillers, based on the Friedel\u2013Crafts reaction between a tetraphenyl methane monomer and a bromomethyl benzene monomer. According to the temperature and the solvent used during the reaction (dichloromethane (DCM) or dichloroethane (DCE)), two different particle sizes have been obtained, 498 nm with DCM and 120 nm with DCE. The change in the reaction process also induces a change in the surface area and pore volumes. Several MMMs have been developed with PIM-1 as matrix and HCPs as fillers at 3% and 10wt % loading. Their permeation performances have been studied over the course of two years in order to explore physical aging effects over time. Without filler, PIM-1 exhibits the classical aging behavior of polymers of intrinsic microporosity, namely, a progressive decline in gas permeation, up to 90% for CO2 permeability. On the contrary, with HCPs, the physical aging at longer terms in PIM-1 is moderated with a decrease of 60% for CO2 permeability.13C spin-lattice relaxation times (T1) indicates that this slowdown is related to the interactions between HCPs and PIM-1

CREB engages C/EBPδ to initiate leukemogenesis.

cAMP response element binding protein (CREB) is frequently overexpressed in acute myeloid leukemia (AML) and acts as a proto-oncogene; however, it is still debated whether such overactivation alone is able to induce leukemia as its pathogenetic downstream signaling is still unclear. We generated a zebrafish model overexpressing CREB in the myeloid lineage, which showed an aberrant regulation of primitive hematopoiesis, and in 79% of adult CREB-zebrafish a block of myeloid differentiation, triggering to a monocytic leukemia akin the human counterpart. Gene expression analysis of CREB-zebrafish revealed a signature of 20 differentially expressed human homologous CREB targets in common with pediatric AML. Among them, we demonstrated that CREB overexpression increased CCAAT-enhancer-binding protein-δ (C/EBPδ) levels to cause myeloid differentiation arrest, and the silencing of CREB-C/EBPδ axis restored myeloid terminal differentiation. Then, C/EBPδ overexpression was found to identify a subset of pediatric AML affected by a block of myeloid differentiation at monocytic stage who presented a significant higher relapse risk and the enrichment of aggressive signatures. Finally, this study unveils the aberrant activation of CREB-C/EBPδ axis concurring to AML onset by disrupting the myeloid cell differentiation process. We provide a novel in vivo model to perform high-throughput drug screening for AML cure improvement

tungsten oxide a catalyst worth studying for the abatement and decontamination of chemical warfare agents

AbstractTungsten(VI) oxide, WO3, was studied and used as a heterogeneous catalyst for the liquid-phase oxidative abatement and solid-phase decontamination of simulants of chemical warfare agents, CWAs. The catalytic performance of WO3 was compared to the one of a soluble W-containing model catalyst, W(IV)-heptaisobutyl polyhedral oligomeric silsesquioxane, W-POSS. In liquid-phase abatement tests, WO3 promoted a complete degradation of the toxic agent simulant within 24 h, in the presence of aqueous hydrogen peroxide, at room temperature. In solid-phase decontamination tests, when WO3 was mixed with sodium perborate as a solid oxidant, it was also tested in the decontamination of a cotton textile support from organosulfide and organophosphonate agents (simulants of blistering and nerve CWAs, respectively), showing promising performances comparable to, or sometimes better than, a nanostructured TiO2 catalyst, taken as a reference material. The environmental impact of the WO3 catalyst was assessed on biolumi..