Mining activities in general, and quarrying processes in particular, generate huge amounts of tailings with a considerable presence of fine particles and with a variable composition of minerals, ...which could limit the direct application of those wastes. Under the paradigm of a circular economy, more effort has to be made to find adequate applications for those secondary raw materials. In this study, a process was proposed and tests were performed to valorise fine particle product as a raw material for the building and construction industry. Samples were taken from wastes in several aggregate production plants, being characterized and processed to remove the clayey components to obtain the cleanest quartz fraction. Then, different characterization and validation tests were carried out to analyse the application of these products as raw materials in the building and construction industry (cement and ceramics). Results showed that with no complex technologies, the tailings can be considered as a mineral raw material in different applications.
•Complex legacy of contamination afflicts As–Hg brownfields.•As- and Hg-rich waste analyzed in a paradigmatic study site.•Co-ocurrence of a complex speciation of As and Hg, and organic pollution ...(PAHs).•Arsenolite was determined to be the main source of risk at the site.•Unexpected Hg organo-compounds found.
The abandonment of Hg–As mining and metallurgy sites, together with long-term weathering, can dramatically degrade the environment. In this work it is exemplified the complex legacy of contamination that afflicts Hg–As brownfields through the detailed study of a paradigmatic site. Firstly, an in-depth study of the former industrial process was performed to identify sources of different types of waste. Subsequently, the composition and reactivity of As- and Hg-rich wastes (calcines, As-rich soot, stupp, and flue dust) was analyzed by means of multielemental analysis, mineralogical characterization (X-ray diffraction, electronic, and optical microscopy, microbrobe), chemical speciation, and sequential extractions.
As-rich soot in the form of arsenolite, a relatively mobile by-product of the pyrometallurgical process, and stupp, a residue originated in the former condensing system, were determined to be the main risk at the site. In addition, the screening of organic pollution was also aimed, as shown by the outcome of benzo(a) pyrene and other PAHs, and by the identification of unexpected Hg organo-compounds (phenylmercury propionate).
The approach followed unravels evidence from waste from the mining and metallurgy industry that may be present in other similar sites, and identifies unexpected contaminants overlooked by conventional analyses.
The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety ...of targeted and biologic therapies.
To review, from an infectious diseases perspective, the safety profile of therapies targeting different intracellular signaling pathways and to suggest preventive recommendations.
Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family.
Although BCR-ABL tyrosine kinase inhibitors modestly increase the overall risk of infection, dasatinib has been associated with cytomegalovirus and hepatitis B virus reactivation. BRAF/MEK kinase inhibitors do not significantly affect infection susceptibility. The effect of Bruton tyrosine kinase inhibitors (ibrutinib) among patients with B-cell malignancies is difficult to distinguish from that of previous immunosuppression. However, cases of Pneumocystis jirovecii pneumonia (PCP), invasive fungal infection and progressive multifocal leukoencephalopathy have been occasionally reported. Because phosphatidylinositol-3-kinase inhibitors (idelalisib) may predispose to opportunistic infections, anti-Pneumocystis prophylaxis and prevention strategies for cytomegalovirus are recommended. No increased rates of infection have been observed with venetoclax (antiapoptotic protein Bcl-2 inhibitor). Therapy with Janus kinase inhibitors markedly increases the incidence of infection. Pretreatment screening for chronic hepatitis B virus and latent tuberculosis infection must be performed, and anti-Pneumocystis prophylaxis should be considered for patients with additional risk factors. Cancer patients receiving mTOR inhibitors face an increased incidence of overall infection, especially those with additional risk factors (prior therapies or delayed wound healing).
Specific preventive approaches are warranted in view of the increased risk of infection associated with some of the reviewed agents.
The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) consensus document on the safety ...of targeted and biological therapies.
To review, from an infectious diseases perspective, the safety profile of immune checkpoint inhibitors, LFA-3–targeted agents, cell adhesion inhibitors, sphingosine-1-phosphate receptor modulators and proteasome inhibitors, and to suggest preventive recommendations.
Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family.
T-lymphocyte–associated antigen 4 (CTLA-4) and programmed death (PD)-1/PD-1 ligand 1 (PD-L1)-targeted agents do not appear to intrinsically increase the risk of infection but can induce immune-related adverse effects requiring additional immunosuppression. Although CD4+ T-cell lymphopenia is associated with alefacept, no opportunistic infections have been observed. Progressive multifocal leukoencephalopathy (PML) may occur during therapy with natalizumab (anti–α4-integrin monoclonal antibody (mAb)) and efalizumab (anti-CD11a mAb), but no cases have been reported to date with vedolizumab (anti-α4β7 mAb). In patients at high risk for PML (positive anti-JC polyomavirus serology with serum antibody index >1.5 and duration of therapy ≥48 months), the benefit–risk ratio of continuing natalizumab should be carefully considered. Fingolimod induces profound peripheral blood lymphopenia and increases the risk of varicella zoster virus (VZV) infection. Prophylaxis with (val)acyclovir and VZV vaccination should be considered. Proteasome inhibitors also increase the risk of VZV infection, and antiviral prophylaxis with (val)acyclovir is recommended. Anti-Pneumocystis prophylaxis may be considered in myeloma multiple patients with additional risk factors (i.e. high-dose corticosteroids).
Clinicians should be aware of the risk of immune-related adverse effects and PML in patients receiving immune checkpoint and cell adhesion inhibitors respectively.
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•Soil washing performance after nZVI addition was examined.•Dilution effect caused by nZVI was considered for metallurgical accounting purposes.•Nanoparticle addition improved PTE ...removal.•nZVIs were selective for Cu, Pb and Sb.
The present study focuses on soil washing enhancement via soil pretreatment with nanoscale zero-valent iron (nZVI) for the remediation of potentially toxic elements. To this end, soil polluted with As, Cu, Hg, Pb and Sb was partitioned into various grain sizes (500–2000, 125–500 and <125 μm). The fractions were pretreated with nZVI and subsequently subjected, according to grain size, to Wet-High Intensity Magnetic Separation (WHIMS) or hydrocycloning. The results were compared with those obtained in the absence of nanoparticles.
An exhaustive characterization of the magnetic signal of the nanoparticles was done. This provided valuable information regarding potentially toxic elements (PTEs) fate, and allowed a metallurgical accounting correction considering the dilution effects caused by nanoparticle addition.
As a result, remarkable recovery yields were obtained for Cu, Pb and Sb, which concentrated with the nZVI in the magnetically separated fraction (WHIMS tests) and underflow (hydrocyclone tests). In contrast, Hg, concentrated in the non-magnetic fraction and overflow respectively, while the behavior of As was unaltered by the nZVI pretreatment. All things considered, the addition of nZVI enhanced the efficiency of soil washing, particularly for larger fractions (125–2000 μm). The proposed methodology lays the foundations for nanoparticle utilization in soil washing operations.
The present review is part of the ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies.
To review, from an Infectious ...Diseases perspective, the safety profile of agents targeting interleukins, immunoglobulins and complement factors and to suggest preventive recommendations.
Computer-based MEDLINE searches with MeSH terms pertaining to each agent or therapeutic family.
Patients receiving interleukin-1 (IL-1) -targeted (anakinra, canakinumab or rilonacept) or IL-5-targeted (mepolizumab) agents have a moderate risk of infection and no specific prevention strategies are recommended. The use of IL-6/IL-6 receptor-targeted agents (tocilizumab and siltuximab) is associated with a risk increase similar to that observed with anti-tumour necrosis factor-α agents. IL-12/23-targeted agents (ustekinumab) do not seem to pose a meaningful risk of infection, although screening for latent tuberculosis infection may be considered and antiviral prophylaxis should be given to hepatitis B surface antigen-positive patients. Therapy with IL-17-targeted agents (secukinumab, brodalumab and ixekizumab) may result in the development of mild-to-moderate mucocutaneous candidiasis. Pre-treatment screening for Strongyloides stercoralis and other geohelminths should be considered in patients who come from areas where these are endemic who are receiving IgE-targeted agents (omalizumab). C5-targeted agents (eculizumab) are associated with a markedly increased risk of infection due to encapsulated bacteria, particularly Neisseria spp. Meningococcal vaccination and chemoprophylaxis must be administered 2–4 weeks before initiating eculizumab. Patients with high-risk behaviours and their partners should also be screened for gonococcal infection.
Preventive strategies are particularly encouraged to minimize the occurrence of neisserial infection associated with eculizumab.
The present review is aimed at exploring the field of the catalytic cracking of polyolefins over solid acids, focusing on the role played by the catalysts toward the synthesis of fuels and chemicals ...as well as on the reaction systems currently used. Initially, conventional solid acids, such as micrometer sized crystal zeolites and silica–alumina, were used to establish the relationship among their activity, selectivity, and deactivation in the polyolefin cracking and the inherent properties of the catalysts (acidity, pore structure); however, the occurrence of steric and diffusional hindrances for entering the zeolite micropores posed by the bulky nature of the polyolefins highlighted the importance of having easily accessible acid sites, either through mesopores or by a high external surface area. This fact led toward the investigation of mesoporous materials (Al-MCM-41, Al-SBA-15) and nanozeolites, which allowed increasing the catalytic activities, especially for the case of polypropylene. Further advances have come by the application of hierarchical zeolites whose bimodal micropore–mesopore size distribution has turned them into the most active catalysts for polymer cracking. In this regard, hierarchical zeolites may be regarded as a clear breakthrough, and it is expected that future research on them will bring new achievements in the field of catalytic cracking of polyolefins. In addition, other materials with high accessibility toward the active sites, such as extra-large pore zeolites, delaminated zeolites, or pillared zeolite nanosheets, can also be considered potentially promising catalysts. From a commercial point of view, two-step processes seem to be the most feasible option, including a combination of thermal treatments with subsequent catalytic conversion and reforming, which allows the catalytic activity to be preserved against different types of deactivation.
Several metals and metalloids (e.g., As, Cd, Cu, Pb, Zn) are toxic at low concentrations, thus their presence in sediments can raise environmental concern. However, these elements can be of economic ...interest, and several techniques have been used for their recovery and some of them have been widely applied to mining or to industrial soils, but not to sediments. In this work, wet high-intensity magnetic separation (WHIMS) was applied for As, Cd, Cu, Pb and Zn recovery from polluted sediments. A composite sample of 50 kg was taken in the Avilés estuary (Asturias, North Spain) with element concentrations above the legislation limits. Element distribution was assessed using wet-sieving and ICP-MS analysis, revealing that the 125–500 μm grain-size fraction accounts for the 62 w% of the material and that element concentration in this fraction is lower than in the other grain size fractions. Subsequently, WHIMS was applied at three different voltage intensities for the 125–500 μm and <125 μm fractions, revealing excellent recovery ratios, especially for the coarser material. Furthermore, magnetic property measurements coupled to microscopy analysis revealed that the success of the technique derives from concentrating metal-enriched iron oxides particles (ferro- and para-magnetic material) in a mixture of quartz and other minerals (diamagnetic particles). These results indicate the feasibility of the magnetic separation for metal and metalloid recovery from polluted sediments, and thus offer a double benefit of coastal area restoration and valuable material recovery in the context of a circular economy.
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•Magnetic separation is a useful technique for metal recovery from polluted sediments.•Metal-enriched particles (ferro/para-magnetic material) were separated from quartz.•Electron microprobe found As & metals associated to sphalerite and Fe oxides.•This approach leads to clean sediments and recovered elements.
Oral anticoagulants (OACs) are first-line drugs for stroke prevention in patients with atrial fibrillation (AF). The introduction of new lines of therapy with direct oral anticoagulants (DOACs) has ...led to a decreased use of vitamin K antagonists (VKAs). Comparative analyses of DOACs in clinical trials are scarce and the comparator has mostly been warfarin. Their impact on health outcomes in observational studies has not always been consistent. The aim of this study is to evaluate the effectiveness and safety of DOACs and VKAs in patients with AF using Real-World Data (RWD).
The use of quebracho extract as a pyrite depressing agent to improve Cu/Fe ratio in copper minerals flotation was studied. The depressing effect in the case of pure pyrite, pure chalcopyrite and a ...sample of disseminated copper ore was tested considering different pH values and modifiers, and different levels of tannin addition. Results show that quebracho extract can be considered a cleaner option in these processes.
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