Some rare earth elements (REEs) are classified under critical materials, i.e., essential in use and subject to supply risk, due to their increasing demand, monopolistic supply, and environmentally ...unsustainable and expensive mining practices. To tackle the REE supply challenge, new initiatives have been started focusing on their extraction from alternative secondary resources. This study puts the emphasis on technospheric mining of REEs from bauxite residue (red mud) produced by the aluminum industry. Characterization results showed the bauxite residue sample contains about 0.03 wt% REEs. Systematic leaching experiments showed that concentrated HNO
is the most effective lixiviant. However, because of the process complexities, H
SO
was selected as the lixiviant. To further enhance the leaching efficiency, a novel process based on microwave pretreatment was employed. Results indicated that microwave pretreatment creates cracks and pores in the particles, enabling the lixiviant to diffuse further into the particles, bringing more REEs into solution, yielding of 64.2% and 78.7% for Sc and Nd, respectively, which are higher than the maximum obtained when HNO
was used. This novel process of "H
SO
leaching-coupled with-microwave pretreatment" proves to be a promising technique that can help realize the technological potential of REE recovery from secondary resources, particularly bauxite residue.
Salmonella exploit host-derived nitrate for growth in the lumen of the inflamed intestine. The generation of host-derived nitrate is dependent on Nos2, which encodes inducible nitric oxide synthase ...(iNOS), an enzyme that catalyzes nitric oxide (NO) production. However, the cellular sources of iNOS and, therefore, NO-derived nitrate used by Salmonella for growth in the lumen of the inflamed intestine remain unidentified. Here, we show that iNOS-producing inflammatory monocytes infiltrate ceca of mice infected with Salmonella. In addition, we show that inactivation of type-three secretion system (T3SS)-1 and T3SS-2 renders Salmonella unable to induce CC- chemokine receptor-2- and CC-chemokine ligand-2-dependent inflammatory monocyte recruitment. Furthermore, we show that the severity of the pathology of Salmonella- induced colitis as well as the nitrate-dependent growth of Salmonella in the lumen of the inflamed intestine are reduced in mice that lack Ccr2 and, therefore, inflammatory monocytes in the tissues. Thus, inflammatory monocytes provide a niche for Salmonella expansion in the lumen of the inflamed intestine.
In addition to high-fat diet (HFD) and inactivity, inflammation and microbiota composition contribute to obesity. Inhibitory immune receptors, such as NLRP12, dampen inflammation and are important ...for resolving inflammation, but their role in obesity is unknown. We show that obesity in humans correlates with reduced expression of adipose tissue NLRP12. Similarly, Nlrp12−/− mice show increased weight gain, adipose deposition, blood glucose, NF-κB/MAPK activation, and M1-macrophage polarization. Additionally, NLRP12 is required to mitigate HFD-induced inflammasome activation. Co-housing with wild-type animals, antibiotic treatment, or germ-free condition was sufficient to restrain inflammation, obesity, and insulin tolerance in Nlrp12−/− mice, implicating the microbiota. HFD-fed Nlrp12−/− mice display dysbiosis marked by increased obesity-associated Erysipelotrichaceae, but reduced Lachnospiraceae family and the associated enzymes required for short-chain fatty acid (SCFA) synthesis. Lachnospiraceae or SCFA administration attenuates obesity, inflammation, and dysbiosis. These findings reveal that Nlrp12 reduces HFD-induced obesity by maintaining beneficial microbiota.
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•NLRP12 expression is reduced in the adipose tissue of humans with increased obesity•Nlrp12−/− mice show increased weight gain and adipose tissue inflammation•Nlrp12-mediated protection from obesity and inflammation is microbiota dependent•Lachnospiraceae and short-chain fatty acids mitigate obesity and insulin resistance
Truax et al. show that myeloid-expressed NLRP12 restrains high-fat-diet-induced obesity and type 2 diabetes by attenuating TNF, IL-6, NF-kB, MAPK, M1-macrophage polarization, and inflammasome activation in adipose tissue. This protective function of NLRP12 is microbiota dependent, and is associated with Lachnospiraceae and their metabolites, which mitigate obesity.
Ionizing radiation causes acute radiation syndrome, which leads to hematopoietic, gastrointestinal, and cerebrovascular injuries. We investigated a population of mice that recovered from high-dose ...radiation to live normal life spans. These "elite-survivors" harbored distinct gut microbiota that developed after radiation and protected against radiation-induced damage and death in both germ-free and conventionally housed recipients. Elevated abundances of members of the bacterial taxa
and
were associated with postradiation restoration of hematopoiesis and gastrointestinal repair. These bacteria were also found to be more abundant in leukemia patients undergoing radiotherapy, who also displayed milder gastrointestinal dysfunction. In our study in mice, metabolomics revealed increased fecal concentrations of microbially derived propionate and tryptophan metabolites in elite-survivors. The administration of these metabolites caused long-term radioprotection, mitigation of hematopoietic and gastrointestinal syndromes, and a reduction in proinflammatory responses.
The prediction of metabolism and biotransformation pathways of xenobiotics is a highly desired tool in environmental sciences, drug discovery, and (eco)toxicology. Several systems predict single ...transformation steps or complete pathways as series of parallel and subsequent steps. Their performance is commonly evaluated on the level of a single transformation step. Such an approach cannot account for some specific challenges that are caused by specific properties of biotransformation experiments. That is, missing transformation products in the reference data that occur only in low concentrations, e.g. transient intermediates or higher-generation metabolites. Furthermore, some rule-based prediction systems evaluate the performance only based on the defined set of transformation rules. Therefore, the performance of these models cannot be directly compared. In this paper, we introduce a new evaluation framework that extends the evaluation of biotransformation prediction from single transformations to whole pathways, taking into account multiple generations of metabolites. We introduce a procedure to address transient intermediates and propose a weighted scoring system that acknowledges the uncertainty of higher-generation metabolites. We implemented this framework in enviPath and demonstrate its strict performance metrics on predictions of in vitro biotransformation and degradation of xenobiotics in soil. Our approach is model-agnostic and can be transferred to other prediction systems. It is also capable of revealing knowledge gaps in terms of incompletely defined sets of transformation rules.
In this review, we present an extensive summary of research on superhydrophobic electrodeposits reported in the literature over the past decade. As a synthesis technique, electrodeposition is a ...simple and scalable process to produce non-wetting metal surfaces. There are three main categories of superhydrophobic surfaces made by electrodeposition: (i) electrodeposits that are inherently non-wetting due to hierarchical roughness generated from the process; (ii) electrodeposits with plated surface roughness that are further modified with low surface energy material; (iii) composite electrodeposits with co-deposited inert and hydrophobic particles. A recently developed strategy to improve the durability during the application of superhydrophobic electrodeposits by controlling the microstructure of the metal matrix and the co-deposition of hydrophobic ceramic particles will also be addressed.
The objective of the current research is to create multifunctional metal matrix composite coatings that are able to provide high strength as well as high water repellency by electrodeposition of ...nanocrystalline nickel matrix with embedded polytetrafluoroethylene (PTFE) particles. The study of the co-deposition process demonstrated that the amount of PTFE co-deposited is highly dependent on the concentration of PTFE particles in the electroplating bath. A very high fraction of co-deposited PTFE was achieved (69vol.%) using a concentration of 30g/L of PTFE particles in the plating bath. The contact angle of the surface greatly increased when the PTFE content increased over 50vol.%. At 69vol.% PTFE the coatings had a contact angle of 152°. Saccharin was added to the electroplating bath in an attempt to refine grain size. Using transmission electron microscopy, the average grain size of the nickel matrix without saccharin was determined to be 27nm for the coating containing 69vol.% PTFE. However, no nickel grain size reduction was observed when saccharin was added as it was found that the composite samples already had a very fine grain structure likely due to the use of cetyltrimethylammonium bromide (CTAB) as a PTFE particle dispersant. The addition of saccharin provided no additional hardening of the composite while the wetting angle was greatly decreased at concentrations greater than 0.1g/L.
•Anti-wetting Ni–PTFE particle nanocomposite coatings have been produced.•Hardness depends strongly on local PTFE concentration.•Composite hardness can be accounted for by a composite hardness model.•Anti-wetting properties are enhanced by increasing PTFE content.•Saccharin additions to the bath decrease the anti-wetting properties.
Abstract
The renewable-electricity-powered CO
2
electroreduction reaction provides a promising means to store intermittent renewable energy in the form of valuable chemicals and dispatchable fuels. ...Renewable methane produced using CO
2
electroreduction attracts interest due to the established global distribution network; however, present-day efficiencies and activities remain below those required for practical application. Here we exploit the fact that the suppression of *CO dimerization and hydrogen evolution promotes methane selectivity: we reason that the introduction of Au in Cu favors *CO protonation vs. C−C coupling under low *CO coverage and weakens the *H adsorption energy of the surface, leading to a reduction in hydrogen evolution. We construct experimentally a suite of Au-Cu catalysts and control *CO availability by regulating CO
2
concentration and reaction rate. This strategy leads to a 1.6× improvement in the methane:H
2
selectivity ratio compared to the best prior reports operating above 100 mA cm
−2
. We as a result achieve a CO
2
-to-methane Faradaic efficiency (FE) of (56 ± 2)% at a production rate of (112 ± 4) mA cm
−2
.
The Hall-Petch to inverse Hall-Petch (HP-IHP) transition of an electrodeposited nanocrystalline Ni-32at%Co alloy was examined by annealing the as-plated alloy to obtain grain sizes ranging between 18 ...– 239 nm. We describe this transition as an extrinsic HP-IHP transition (extrinsic to the fabrication process) as opposed to the intrinsic HP-IHP transition observed in materials in their as-plated state (intrinsic to the fabrication process). The extrinsic transition of the Ni-32at%Co alloy took place in the mid-stage of abnormal grain growth, at an average grain size of ∼30 nm. Grain boundary relaxation governs the IHP region and maximum hardness was achieved at initial development of bimodal grain size; meanwhile late-stage abnormal grain growth and further normal grain growth led to the reduction in hardness in the HP region. Segregation of sulfur impurities to grain boundaries, crystallographic orientation and annealed twin development did not have significant contributions to the observed change in hardness.
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The cGAS-cyclic GMP-AMP (cGAMP)-stimulator of IFN genes (STING) pathway induces a powerful type I IFN (IFN-I) response and is a prime candidate for augmenting immunity in cancer immunotherapy and ...vaccines. IFN-I also has immune-regulatory functions manifested in several autoimmune diseases and is a first-line therapy for relapsing-remitting multiple sclerosis. However, it is only moderately effective and can induce adverse effects and neutralizing Abs in recipients. Targeting cGAMP in autoimmunity is unexplored and represents a challenge because of the intracellular location of its receptor, STING. We used microparticle (MP)-encapsulated cGAMP to increase cellular delivery, achieve dose sparing, and reduce potential toxicity. In the C57BL/6 experimental allergic encephalomyelitis (EAE) model, cGAMP encapsulated in MPs (cGAMP MPs) administered therapeutically protected mice from EAE in a STING-dependent fashion, whereas soluble cGAMP was ineffective. Protection was also observed in a relapsing-remitting model. Importantly, cGAMP MPs protected against EAE at the peak of disease and were more effective than rIFN-β. Mechanistically, cGAMP MPs showed both IFN-I-dependent and -independent immunosuppressive effects. Furthermore, it induced the immunosuppressive cytokine IL-27 without requiring IFN-I. This augmented IL-10 expression through activated ERK and CREB. IL-27 and subsequent IL-10 were the most important cytokines to mitigate autoreactivity. Critically, cGAMP MPs promoted IFN-I as well as the immunoregulatory cytokines IL-27 and IL-10 in PBMCs from relapsing-remitting multiple sclerosis patients. Collectively, this study reveals a previously unappreciated immune-regulatory effect of cGAMP that can be harnessed to restrain T cell autoreactivity.
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