Herein, we explore a general Cu2−xS nanocube template‐assisted and reverse cation exchange‐mediated growth strategy for fabricating hollow multinary metal sulfide. Unlike the traditional cation ...exchange method controlled by the metal sulfide constant, the introduction of tri‐n‐butylphosphine (TBP) can reverse cation exchange to give a series of hollow metal sulfides. A variety of hollow multinary metal sulfide cubic nanostructures has been demonstrated while preserving anisotropic shapes to the as‐synthesized templates, including binary compounds (CdS, ZnS, Ag2S, PbS, SnS), ternary compound (CuInS2, ZnxCd1−xS), and quaternary compound (single‐atom platinum anchored ZnxCd1−xS; ZnxCd1−xS‐Pt1). Experimental and density functional theory (DFT) calculations show that the hollow metal sulfide semiconductors obtained could significantly improve the separation and migration of photogenerated electron‐hole pairs. Owing to the efficient charge transfer, the ZnxCd1−xS‐Pt1 exhibited outstanding photocatalytic performance of CO2 to CO, with the highest CO generation rate of 75.31 μmol h−1.
A Cu2−xS nanocube template‐assisted route inspired by the hard soft acid base (HSAB) principle was employed for successfully synthesizing a family of hollow metal sulfide (CdS, ZnS, Ag2S, PbS, SnS, CuInS2, ZnxCd1−xS, ZnxCd1−xS‐Pt1) via cation exchange reaction.
Abstract Background Sodium polystyrene sulfonate (Kayexalate; Sanofi-Aventis, Paris, France) is a cation-exchange resin routinely used in the management of hyperkalemia. However, its use has been ...associated with colonic necrosis and other fatal gastrointestinal adverse events. Although the addition of sorbitol to sodium polystyrene sulfonate preparations was previously believed to be the cause of gastrointestinal injury, recent reports have suggested that sodium polystyrene sulfonate itself may be toxic. Our objective was to systematically review case reports of adverse gastrointestinal events associated with sodium polystyrene sulfonate use. Methods MEDLINE (1948 to July 2011), EMBASE (1980 to July 2011), Cochrane Central Register of Controlled Trials (CENTRAL) (1993 to July 27, 2011), bibliographies of identified articles, and websites of relevant drug agencies and professional associations in the United States and Canada were reviewed to identify eligible reports of adverse gastrointestinal events associated with sodium polystyrene sulfonate use. Causality criteria of the World Health Organization causality assessment system were applied to each report. Results Thirty reports describing 58 cases (41 preparations containing sorbitol and 17 preparations without sorbitol) of adverse events were identified. The colon was the most common site of injury (n = 44; 76%), and transmural necrosis (n = 36; 62%) was the most common histopathologic lesion reported. Mortality was reported in 33% of these cases due to gastrointestinal injury. Conclusions Sodium polystyrene sulfonate use, both with and without sorbitol, may be associated with fatal gastrointestinal injury. Physicians must be cognizant of the risk of these adverse events when prescribing this therapy for the management of hyperkalemia.
Treatment options for hyperkalemia have not changed much since the introduction of the cation exchange resin, sodium polystyrene sulfonate (Kayexalate, Covis Pharmaceuticals, Cary, NC), over 50 years ...ago. Although clinicians of that era did not have ready access to hemodialysis or loop diuretics, the other tools that we use today—calcium, insulin, and bicarbonate—were well known to them. Currently recommended insulin regimens provide too little insulin to achieve blood levels with a maximal kalemic effect and too little glucose to avoid hypoglycemia. Short-acting insulins have theoretical advantages over regular insulin in patients with severe kidney disease. Although bicarbonate is no longer recommended for acute management, it may be useful in patients with metabolic acidosis or intact kidney function. Kayexalate is not effective as acute therapy, but a new randomized controlled trial suggests that it is effective when given more chronically. Gastrointestinal side effects and safety concerns about Kayexalate remain. New investigational potassium binders are likely to be approved in the coming year. Although there are some concerns about hypomagnesemia and positive calcium balance from patiromer, and sodium overload from ZS-9 (ZS Pharma, Coppell, TX), both agents have been shown to be effective and well tolerated when taken chronically. ZS-9 shows promise in the acute treatment of hyperkalemia and may make it possible to avoid or postpone the most effective therapy, emergency hemodialysis.
Precisely engineering the electrical conductivity represents a promising strategy to design efficient catalysts towards oxygen evolution reaction (OER). Here, we demonstrate a versatile partial ...cation exchange method to fabricate lamellar Ag‐CoSe2 nanobelts with controllable conductivity. The electrical conductivity of the materials was significantly enhanced by the addition of Ag+ cations of less than 1.0 %. Moreover, such a trace amount of Ag induced a negligible loss of active sites which was compensated through the effective generation of active sites as shown by the excellent conductivity. Both the enhanced conductivity and the retained active sites contributed to the remarkable electrocatalytic performance of the Ag‐CoSe2 nanobelts. Relative to the CoSe2 nanobelts, the as‐prepared Ag‐CoSe2 nanobelts exhibited a higher current density and a lower Tafel slope towards OER. This strategy represents a rational design of efficient electrocatalysts through finely tuning their electrical conductivities.
Conducting materials: Silver‐doped cobalt(II) selenide (Ag‐CoSe2) nanobelts have been synthesized. Their electrocatalytic properties for the oxygen evolution reaction were studied (j(η=0.35 V)=current density at an overpotential of 0.35 V).
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•The removal of multivalent cations from sludge decreased hydrolase activity.•SCFAs producing bacteria were enriched during CER-enhanced anaerobic fermentation.•SCFAs consuming ...bacteria were vulnerable to the lack in multivalent cations.•The lack in multivalent cations was the key factor in microbial community shifts.•Multivalent cation removal modified microbial community to boost SCFAs production.
The correlation of the lack in multivalent cations with hydrolase activity and microbial community in anaerobic fermentation of waste activated sludge was investigated in this study. It was demonstrated that considerable solid phase reduction of 41 % (7.87 g/L) was achievable through a cation exchange resin-enhanced anaerobic fermentation of 4 days. The protease and α-glucosidase, especially α-glucosidase, were easily influenced by a lack in multivalent cations. Furthermore, species abundance and diversity of microbial community gradually decreased. Meanwhile, the bacteria community structure presented obvious dynamic shifts. Ruminococcaceae_UCG_009, Bacteroides and Macellibacteroides responsible for organic matter biodegradation and SCFAs production became dominant bacteria in cation exchange resin-enhanced anaerobic fermentation, which was less influenced by the lack in multivalent cations, while the SCFA consumers (e.g. methanogens) were inhibited with reduced abundances due to their susceptibility to the lack in multivalent cations. Redundancy analysis revealed that the lack in multivalent cations were responsible for the microbial community evolution, which was proved by the high Grey relational coefficients (0.747−0.820) and significant negative Spearman coefficients (−0.5798 to −0.9429) between multivalent cation and microbial community. Obviously, the cation exchange resin-induced removal of multivalent cations reduced enzyme activity and modified microbial community structure, which created a beneficial environment for enhancing anaerobic fermentation.
Strontium-90 (90Sr) is a major contaminant at nuclear legacy sites. The mobility of 90Sr is primarily governed by sorption reactions with sediments controlled by high surface area phases such as clay ...and iron oxides. Sr2+ adsorption was investigated in heterogeneous unconsolidated aquifer sediments, analogous to those underlying the UK Sellafield nuclear site, with grainsizes ranging from gravels to clays. Batch sorption tests showed that a linear Kd adsorption model was applicable to all grainsize fractions up to equilibrium Sr of 0.28 mmol L−1. Sr2+ sorption values (Kd; Langmuir qmax) correlated well with bulk sediment properties such as cation exchange capacity and surface area. Electron microscopy showed that heterogeneous sediments contained porous sandstone clasts with clay minerals (i.e. chlorite) providing an additional adsorption capacity. Therefore, gravel corrections that assumed that the > 2 mm fractions are inert were not appropriate and underestimated Kd(bulk) adsorption coefficients. However, Kd (<2 mm) values measured from sieved sediment fractions, were effectively adjusted to within error of Kd (bulk) using a surface area dependant gravel correction based on particle size distribution data. Amphoteric pH dependent Sr2+ sorption behaviour observed in batch experiments was consistent with cation exchange modelling between pH 2–7 derived from the measured cation exchange capacities. Above pH 7 model fits were improved by invoking a coupled cation exchange/surface complexation which allowed for addition sorption to iron oxide phases. The overall trends in Sr2+ sorption (at pH 6.5–7) produced by increasing solution ionic strength was also reproduced in cation exchange models. Overall, the results showed that Sr2+ sorption to heterogeneous sediment units could be estimated from Kd (<2 mm) data using appropriate gravel corrections, and effectively modelled using coupled cation exchange and surface complexation processes.
•Sr sorption was determined in a range of heterogeneous aquifer sediments.•Gravels contained porous sandstone clasts containing clays and iron oxides.•Kd(bulk) could be estimated from Kd(<2 mm) using appropriate gravel corrections.•pH and ionic strength effects could be modelled as cation exchange processes.
Summary
Soil is a non‐renewable resource that requires constant monitoring to prevent its degradation and promote its sustainable management. The ‘Land Use/Cover Area frame statistical Survey Soil’ ...(LUCAS Soil) is an extensive and regular topsoil survey that is carried out across the European Union to derive policy‐relevant statistics on the effect of land management on soil characteristics. Approximately 45 000 soil samples have been collected from two time‐periods, 2009–2012 and 2015. A new sampling series will be undertaken in 2018, with new measurements included. The organization for the 2018 sampling campaign represents an opportunity to summarize past LUCAS Soil achievements and present its future objectives. In 2009–2012 and 2015, LUCAS Soil surveys targeted physicochemical properties, including pH, organic carbon, nutrient concentrations and cation exchange capacity. Data from 2009–2012 (ca. 22 000 points) and derived output (more than 20 maps) are available freely from the European Soil Data Centre website. Analyses of samples collected during 2015 are ongoing and data will be available at the end of 2017. In the 2018 LUCAS Soil sampling campaign, additional properties, including bulk density, soil biodiversity, specific measurements for organic‐rich soil and soil erosion will be measured. Here we present the current dataset (LUCAS Soil 2009–2012 and 2015), its potential for reuse and future development plans (LUCAS Soil 2018 and over). LUCAS Soil represents the largest harmonized open‐access dataset of topsoil properties available for the European Union at the global scale. It was developed as an expandable resource, with the possibility to add new properties and sampling locations during successive sampling campaigns. Data are available to the scientific community and decision makers, thus contributing to both research and the development of the land‐focused policy agenda.
Highlights
LUCAS Soil consists of soil physicochemical and biological properties data from Europe.
Harmonized and open‐access dataset allowing inclusion of soil in large‐scale inter‐disciplinary assessments.
LUCAS Soil has a broad pool of users from scientists to policy makers, and applications from map validation to modelling.
LUCAS Soil confirms the need for open‐access and a large‐scale dataset for soil properties.
The construction of biocompatible and trackable‐imaging single‐atom nanozymes (SAzymes) with efficient catalytic activities is particularly desirable. Here, cobalt/titanium oxide (Co/TiO2) SAzymes ...are presented with cobalt atomically dispersed on nanoporous hollow TiO2 using a cation‐exchange strategy. Significantly, by varying the calcination conditions, the enzyme‐like activity can be enhanced tenfold. It is determined that different calcination treatments result in valence state shifts of the Co active site due to changes in the amounts of defects, which affects the catalytic kinetics. Moreover, Co/TiO2 SAzymes exhibit good intrinsic biocompatibility and excellent tolerance toward the biological medium, while the hollow structure facilitates the loading of drugs and imaging agents for image‐guided chemo‐chemodynamic therapy via intravenous injection. This study not only provides a paradigm shift for the preparation of biocompatible SAzymes but also presents new insights for modulating the catalytic activity of SAzymes.
Here, highly biocompatible water‐stable hollow sphere Co/TiO2 SAzymes with tailored local charges are reported, which exhibit significant potential as an effective multifunctional nanoplatform for multimodal image‐guided (fluorescence‐19F MRI) tumor chemo‐chemodynamic synergistic therapy.
Hybrid materials, integrating the merits of individual components, are ideal structures for efficient oxygen evolution reaction (OER). However, the rational construction of hybrid structures with ...decent physical/electrochemical properties is yet challenging. Herein, a promising OER electrocatalyst composed of trimetallic metal‐organic frameworks supported over S/N‐doped carbon macroporous fibers (S/N‐CMF@FexCoyNi1‐x‐y‐MOF) via a cation‐exchange strategy is delicately fabricated. Benefiting from the trimetallic composition with improved intrinsic activity, hollow S/N‐CMF matrix facilitating exposure of active sites, as well as their robust integration, the resultant S/N‐CMF@FexCoyNi1‐x‐y‐MOF electrocatalyst delivers outstanding activity and stability for alkaline OER. Specifically, it needs an overpotential of 296 mV to reach the benchmark current density of 10 mA cm−2 with a small Tafel slope of 53.5 mV dec−1. In combination with X‐ray absorption fine structure spectroscopy and density functional theory calculations, the post‐formed Fe/Co‐doped γ‐NiOOH during the OER operation is revealed to account for the high OER performance of S/N‐CMF@FexCoyNi1‐x‐y‐MOF.
Trimetallic metal‐organic frameworks supported over the hollow S/N‐doped carbon macroporous fibers (S/N‐CMF@FexCoyNi1‐x‐y‐MOF) are prepared as a promising electrocatalyst for the oxygen evolution reaction (OER). Benefiting from the trimetallic composition with improved intrinsic activity, hollow S/N‐CMF matrix facilitating active sites exposure, as well as their robust integration, the resultant S/N‐CMF@FexCoyNi1‐x‐y‐MOF electrocatalyst delivers excellent OER performance with an overpotential of 296 mV at 10 mA cm−2, a Tafel slope of 53.5 mV dec−1, and outstanding durability.
•Cation exchange and multimodal cationic resin (mixed mode) were compared for the capture of an antibody.•Microplates experiments and lab scale validation indicated that both resins were able to ...capture an antibody with good yield and purity.•Mixed mode resin showed better performances according to yield and HCPs removal and a greater robustness
We compared classical and multimodal cation exchange resins for the capture of recombinant antibodies from Chinese hamster ovary (CHO) cell culture supernatant. Both Capto S and Capto MMC resins present anionic groups while the multimodal Capto MMC also features a hydrophobic moiety. First we screened optimal binding and elution conditions in microplates with a pure antibody. We validated the results on the lab-scale with columns with a pure antibody and a CHO cell culture supernatant. Both resins achieved good yield and purity for the capture step of an antibody. However, the multimodal resin appeared more efficient and selective. Then we identified proteins in the antibody fraction by mass spectrometry in order to highlight the behavior of host cell proteins (HCPs).
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