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Context: Given the diverse pathophysiological mechanisms underlying Alzheimer's disease, it is improbable that a single targeted drug will prove successful as a therapeutic strategy. Therefore, exploring various hypotheses in drug design is imperative. The sequestration of Fe(II) and Zn(II) cations stands out as a crucial mechanism based on the mitigation of reactive oxygen species. Moreover, inhibiting acetylcholinesterase represents a pivotal strategy to enhance acetylcholine levels in the synaptic cleft. This research aims to investigate the analogs of Huperzine A, documented in scientific literature, considering of these two hypotheses. Consequently, the speciation chemistry of these structures with Fe(II) and Zn(II) was scrutinized using quantum chemistry calculations, molecular docking simulations, and theoretical predictions of pharmacokinetics properties. From the pharmacokinetic properties, only two analogs, HupA-A1 and HupA-A2, exhibited a theoretical permeability across the blood-brain barrier; on the other hand, from a thermodynamic standpoint, the enantiomers of HupA-A2 showed negligible chelation values. The enantiomers with the most favorable interaction parameters were S′R′HupA-A1 (ΔGBIND = −40.0 kcal mol−1, fitness score = 35.5) and R′R′HupA-A1 (ΔGBIND = −35.5 kcal mol−1, fitness score = 22.61), being compared with HupA (ΔGBIND = −41.75 kcal mol−1, fitness score = 39.95). From this study, some prime candidates for promising drug were S′R′HupA-A1 and R′R′HupA-A1, primarily owing to their favorable thermodynamic chelating capability and potential anticholinesterase mechanism. Methods: Quantum chemistry calculations were carried out at B3LYP/6-31G(d) level, considering the IEF-PCM(UFF) implicit solvent model for water. The coordination compounds were assessed using the Gibbs free energy variation and hard and soft acid theory. Molecular docking calculations were conducted using the GOLD program, based on the crystal structure of the acetylcholinesterase protein (PDB code = 4EY5), where the ChemScore function was employed with the active site defined as the region within a 15-Å radius around the centroid coordinates (X = −9.557583, Y = −43.910473, Z = 31.466687). Pharmacokinetic properties were predicted using SwissADME, focusing on Lipinski's rule of five. [ABSTRACT FROM AUTHOR]

Rice provides ~20% of human dietary energy and, for many people, a similar share of their protein. Rice cultivation, however, produces significant greenhouse gas (GHG) emissions, comparable to those from the aviation sector. The main GHG from rice production is methane, mostly a result of conventional rice cultivation (CRC) keeping rice fields continuously flooded during the crop cycle. There is extensive evidence that alternate wetting and drying (AWD) of rice fields substantially reduces methane emissions. AWD is one component of the System of Rice Intensification (SRI), an agroecological approach to the management of plants, water, soil, and nutrients. This article reviews field studies measuring GHG emissions associated with the adoption of AWD and SRI. The review confirms that both AWD and SRI offer substantial reductions in methane emissions per hectare compared with CRC. These benefits are, however, partly offset by increases in emissions of nitrous oxide and carbon dioxide. The studies also show that SRI (but not AWD) improves yield and therefore further reduces GHG emissions per kg of rice. The review concludes that while both AWD and SRI substantially reduce emissions per hectare and per kilogram of rice, SRI can simultaneously contribute to food security while addressing the drivers of climate change. Further investigation of carbon emissions and sequestration under different rice cultivation methods is needed to strengthen the evidence base. [ABSTRACT FROM AUTHOR]

Mangroves and saltmarshes are biogeochemical hotspots storing carbon in sediments and in the ocean following lateral carbon export (outwelling). Coastal seawater pH is modified by both uptake of anthropogenic carbon dioxide and natural biogeochemical processes, e.g., wetland inputs. Here, we investigate how mangroves and saltmarshes influence coastal carbonate chemistry and quantify the contribution of alkalinity and dissolved inorganic carbon (DIC) outwelling to blue carbon budgets. Observations from 45 mangroves and 16 saltmarshes worldwide revealed that >70% of intertidal wetlands export more DIC than alkalinity, potentially decreasing the pH of coastal waters. Porewater-derived DIC outwelling (81 ± 47 mmol m−2 d−1 in mangroves and 57 ± 104 mmol m−2 d−1 in saltmarshes) was the major term in blue carbon budgets. However, substantial amounts of fixed carbon remain unaccounted for. Concurrently, alkalinity outwelling was similar or higher than sediment carbon burial and is therefore a significant but often overlooked carbon sequestration mechanism. Global observations from mangroves and saltmarshes unravel hidden carbon pathways. Inorganic carbon outwelling is revealed to dominate carbon budgets, impact coastal pH, and enhance the climate mitigation potential of blue carbon ecosystems. [ABSTRACT FROM AUTHOR]

Nickel (Ni) is a key component of the active site metallocofactors of numerous enzymes required for methanogenesis, including [NiFe]-hydrogenase, carbon monoxide dehydrogenase, and methyl CoM reductase, leading to a high demand for Ni among methanogens. However, methanogens often inhabit euxinic environments that favor the sequestration of nickel as metal-sulfide minerals, such as nickelian pyrite [(Ni, Fe)S2], that have low solubilities and that are not considered bioavailable. Recently, however, several different model methanogens (Methanosarcina barkeri, Methanococcus voltae, Methanococcus maripaludis) were shown to reductively dissolve pyrite (FeS2) and to utilize dissolution products to meet iron and sulfur biosynthetic demands. Here, using M. barkeri Fusaro, and laboratory-synthesized (Ni, Fe)S2 that was physically isolated from cells using dialysis membranes, we show that trace nickel (<20 nM) abiotically solubilized from the mineral can support methanogenesis and limited growth, roughly fivefold less than the minimum concentration known to support methanogenesis. Furthermore, when provided direct contact with (Ni, Fe)S2, M. barkeri promoted the reductive dissolution of (Ni, Fe)S2 and assimilated solubilized nickel, iron, and sulfur as its sole source of these elements. Cells that reductively dissolved (Ni, Fe)S2 bioaccumulated approximately fourfold more nickel than those grown with soluble nickel and sulfide but had similar metabolic coupling efficiencies. While the mechanism for Ni uptake in archaeal methanogens is not known, homologs of the bacterial Nik uptake system were shown to be ubiquitous across methanogen genomes. Collectively, these observations indicate that (Ni, Fe)S2 is bioavailable in anoxic environments and that methanogens can convert this mineral into nickel-, iron-, and sulfur-containing metalloenzymes to support methanogenesis and growth. [ABSTRACT FROM AUTHOR]

Mineral replacement reactions mediated by fluids are common in sedimentary basins, where they influence geochemical cycles. Phosphorous (P) pollution of soils, sediments and water bodies is currently a widespread problem. Some apatite accumulations in sediments may have formed through the interaction of P-bearing aqueous solutions with mineral surfaces that result in mineral replacement reactions. Here, we investigate the pseudomorphic replacement of anhydrite single crystals by aggregates of β-tricalcium phosphate and hydroxyapatite upon interaction with a P-bearing solution at temperatures between 120 and 200 °C. SEM imaging is used to study the texture of the aggregates. Rietveld refinement of the X-ray diffraction patterns and Raman spectra analysis of the reacted samples provide information on the kinetics of the replacement. At all temperatures β-tricalcium phosphate forms alongside hydroxyapatite at early stages of the replacement reaction. At T ≥ 180 °C, hydroxyapatite/β-tricalcium phosphate ratio rapidly increases, and hydroxyapatite is the only phase in fully replaced samples. At T < 180 °C hydroxyapatite/β-tricalcium phosphate ratio increases slowly and fully replaced samples still contain significant amounts of β-tricalcium phosphate. The progress of the replacement is facilitated by the formation of porosity. The evolution of the hydroxyapatite/β-tricalcium phosphate ratio and the crystal habit of both phases strongly influence the arrangement of this porosity. The empirical activation energy Ea (kJ/mol) of the replacement reaction is determined by the Avrami and the iso-conversion methods. Both approaches yield an Ea of ~40 kJ/mol. Anhydrite dissolution appears as the rate-limiting process and the overall kinetics of the replacement reaction is controlled by the rate diffusion of dissolved species through the porosity network. The ripening of the metastable β-tricalcium phosphate into hydroxyapatite affects the characteristics of the porosity network and further modulates the kinetics of the replacement. These results may improve the understanding of the mechanisms of P-sequestration by mineral surfaces through coupled dissolution–precipitation reactions and shed light on the origin of apatite accumulations associated to evaporitic sedimentary rocks. [ABSTRACT FROM AUTHOR]

The article reports on a new hybrid sorbent containing polyamine-Cu(II) complex, Polyam-N-Cu2+, which shows high CO2 capture capacity at ultradilute concentrations of CO2 in the atmosphere. The sorbent is mechanically strong, chemically stable, and amenable to efficient regeneration by salt solutions at an ambient temperature, including seawater, making it an ideal candidate for use in direct air capture (DAC) systems for removing CO2 from the atmosphere.

Increases in community and industrial activities have led to disturbances of the environmental balance and the contamination of water systems through the introduction of organic and inorganic pollutants. Among the various inorganic pollutants, Pb (II) is one of the heavy metals possessing non-biodegradable and the most toxic characteristics towards human health and the environment. The present study is focussed on the synthesis of efficient and eco-friendly adsorbent material that can remove Pb (II) from wastewater. A green functional nanocomposite material based on the immobilization of α-Fe2O3 nanoparticles with xanthan gum (XG) biopolymer has been synthesized in this study to be applied as an adsorbent (XGFO) for sequestration of Pb (II). Spectroscopic techniques such as scanning electron microscopy with energy dispersive X-ray (SEM-EDX), Fourier transform infrared (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet visible (UV-Vis) and X-ray photoelectron spectroscopy (XPS) were adopted for characterizing the solid powder material. The synthesized material was found to be rich in key functional groups such as –COOH and –OH playing important roles in binding the adsorbate particles through ligand-to-metal charge transfer (LMCT). Based on the preliminary results, adsorption experiments were conducted, and the data obtained were applied to four different adsorption isotherm models, viz the Langmuir, Temkin, Freundlich and D–R models. Based on the high values of R2 and low values of χ2, the Langmuir isotherm model was found to be the best model for simulation of data for Pb (II) adsorption by XGFO. The value of maximum monolayer adsorption capacity (Qm) was found to be 117.45 mg g−1 at 303 K, 126.23 mg g−1 at 313 K, 145.12 mg g−1 at 323 K and 191.27 mg g−1 at 323 K. The kinetics of the adsorption process of Pb (II) by XGFO was best defined by the pseudo-second-order model. The thermodynamic aspect of the reaction suggested that the reaction is endothermic and spontaneous. The outcomes proved that XGFO can be utilized as an efficient adsorbent material for the treatment of contaminated wastewater. [ABSTRACT FROM AUTHOR]

Background: Organic materials carbon is mainly sequestrated in humin. However, the carbon (C) stability of humin with organic materials amendments in different types of soils is mainly affected by organic materials or soil types as well as the enzymatic reaction is important for understanding the C sequestration mechanism of soil. Results: In this study, straw and straw-derived biochar were incorporated into three different types of soils. Using 13C nuclear magnetic resonance (NMR) spectroscopy, the structural composition of humin (Hu) was analyzed, along with the urease and β-glucosidase activities. The results showed that biochar amendment enhanced aryl C to 49.63%–76.55% while straw amendments increased O-alkyl C of Hu to 33.99%–51.70%. Two-way ANOVA analysis revealed significant differences in the impact of soil types and treatments on enzyme activities and functional groups of humin. A significant positive correlation was found between β-glucosidase activity and O-alkyl C, phenolic C, and methoxyl C of humin. In addition, urease activity showed a significant positive correlation with alkyl C of humin. Compared to tobacco straw, tobacco straw-biochar amendment increased β-glucosidase activity for 22.01 mg kg−1 d−1, 26.01 mg kg−1 d−1 and 14.01 mg kg−1 d−1 in three types of soils, respectively. Conclusions: These results showed that β-glucosidase contributed to the transformation of humin functional groups and was influenced by organic materials and soil types, especially the organic materials types. The findings imply that straw or straw-derived biochar application stimulates urease and β-glucosidase activities, which improves the alternation of functional groups of humin in different types of soil. [ABSTRACT FROM AUTHOR]

The potential of a biosorbent derived from Arundo donax stem, a readily available agricultural product, was examined to remove Cr(VI) from water. Various techniques such as XRD, FTIR, SEM, and EDX were used for the characterization of the prepared adsorbent. The optimal pH for Cr(VI) biosorption was found to be 2.0. The experimental data best suits the Langmuir isotherm model and pseudosecond-order kinetics. The maximum biosorption capacity (qmax) of the investigated biosorbent for Cr(VI) was evaluated to be 76.92 mg/g by the Langmuir model. From the results of the Cr(VI) biosorption using charred Arundo donax stem powder (CADSP), it can be a novel, cost-efficient, and effective material for removing Cr(VI) from water and wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • s-ZVI-coupled Myriophyllum aquaticum- derived biochar favors C storage more than I.H. • Biochar nature or feedstock may control C trap and N removal gains from Fe-C coupling. • Biochars trigger C dynamics depending on trade-offs between priming and increased MBC. • Enhanced iron gate contributes to synergistic C sequestration and C sink augmentation. • β -glucosidase activity and Fe-OC increases jointly drive C cumulation in Fe-C ditches. Carbon dioxide (CO 2) is a more powerful greenhouse gas due to its enhanced instantaneous radiative forcing. Since agricultural ecological ditches (eco-ditches) controlling agricultural non-point source pollution are potential CO 2 hotspots, carbon capture technologies must be deployed immediately to sequester carbon and combat climate change. Zero-waste biochar, a negative-carbon technology, remains contentious regarding C sequestration. Iron (Fe) enhances long-term organic carbon (OC) preservation, but the cascading effects of Fe-biochar interactions on the promotion of C accumulation are unclear in eco-ditches. In this paper, we fill these research gaps and employ sponge iron (s-ZVI) and biochar coupling (Fe-C) to enhance the iron gate C protection in eco-ditches. The results reveal that Myriophyllum aquaticum(M.A.) -derived biochar prepared by low-temperature pyrolysis (Biochar_M.A.) enjoys the highest FI, the lowest SUVA254 and SUVA280 and moderate dissolution stability. The coupling of s-ZVI and environmentally compatible Biochar_M.A. achieve a triple benefit situation of C sequestration, C sink, and pollutant removal. Overall carbon gain is jointly determined by abiotic controls and biotic controls. The carbon burial effects of biochar-amended eco-ditches are mainly controlled by the trade-offs between Fe-bound OC mineralization via the biochar-induced prime effect and preservation of OC derived from microbial biomass. The unique Fe-C boosts the rusty sink and yields a negative priming as a result of the dominance of Fe-OC. The upregulated β -glucosidase activity and new-formed Fe-OC indirectly and directly contribute to overall C gain in Fe-C-filled eco-ditches, respectively. These findings provide novel insights into the coupled biotic-abiotic contribution mechanisms underlying the iron gate and reverse enzyme latch phenomenon and advance more robust and prospective theoretical knowledge of C dynamics that are not restricted to eco-ditches, soil, constructed wetlands C storage. [ABSTRACT FROM AUTHOR]

Nanomaterials have gained much attention in the field of environmental remediation, largely due to their high surface area-to-volume ratio and other unique physical, chemical, and biological characteristics that emerge due to its size effects. Metallic nanoparticles are traditionally manufactured using wet chemical processes; however, the chemicals utilized are generally hazardous and combustible. The biosynthesis of nanoparticles using a variety of plant resources is considered a green technology because it does not use toxic chemicals. This work focuses on the green synthesis of biogenetic silver nanoparticles and their use in the sequestration of colorants from aqueous solution. The extract of aquatic macrophyte Salvinia molesta (water hyacinth) has been employed to prepare silver nanoparticles by chemical reduction reaction. In the UV-visible spectrum of the synthesized silver nanoparticles, the absorbance peak was detected in the 420–430 nm range. The synthesized silver nanoparticles were used to sequester methylene blue (MB) dye in aqueous solution. About 121.04 mg/g was found as the highest adsorption capacity of methylene blue dye on the silver nanoparticles according to the Langmuir isotherm. It was observed that the experimental results and the pseudo-second order kinetics are in good agreement. As a result, the biosynthesized silver nanoparticle might be a potential adsorbent material in the field of environmental rehabilitation and cleanup. [ABSTRACT FROM AUTHOR]

This correction notice is for an article titled "Carbonate chemistry and carbon sequestration driven by inorganic carbon outwelling from mangroves and saltmarshes" published in Nature Communications. The correction addresses an error in the original version of the Supplementary Information, where the citation for certain sites was incorrect. The correction provides the accurate citation and updates the HTML version of the Supplementary Information accordingly. The article was authored by a group of researchers and includes their names at the end of the correction notice. [Extracted from the article]

CO2 in the atmosphere is a major contributor to global warming but at the same time it has the potential to be a carbon source for advanced biomanufacturing. To utilize CO2, carbonic anhydrase has been identified as a key enzyme. Furthermore, attempts have been made to accelerate the sequestration via pressure. This study aims to combine both approaches to achieve high sequestration rates. The carbonic anhydrase of the alkaliphilic cyanobacterium Coleofasciculus chthonoplastes (cahB1) and bovine carbonic anhydrase (BCA) are introduced into a high‐pressure reactor to catalyze the hydration of CO2 at up to 20 bar. The reactor is filled with a CaCl2 solution. Due to the presence of Ca2+, the hydrated CO2 precipitates as CaCO3. The impact of the carbonic anhydrase is clearly visible at all pressures tested. At ambient pressure a CO2 sequestration rate of 243.68 kgCaCO3/m3 h for cahB1 was achieved compared to 150.41 kgCaCO3/m3 h without enzymes. At 20 bar the rates were 2682.88 and 2267.88 kgCaCO3/m3 h, respectively. The study shows the benefit of a combined CO2 sequestration process. To examinate the influence of the enzymes on the product formation, the precipitated CaCO3 was analyzed regarding the crystalline phase and morphology. An interchange of the crystalline phase from vaterite to calcite was observed and discussed. [ABSTRACT FROM AUTHOR]

The shale fracture permeability is critical in determining gas production and deep CO2 sequestration performance. Moreover, how shale fracture permeability evolves after interactions with supercritical carbon dioxide (Sc-CO2) should be understood to constrain the shale reservoir permeability and evaluate the long-term sealing ability of shale formations. In this research, we conducted soaking experiments with shale fractures and Sc-CO2 at various times and then measured the shale fracture permeability and hydraulic aperture evolution under different stress states. Additionally, we quantify the chemical compositions, pore characteristics, fracture surface roughness alternation through X-ray diffraction, nuclear magnetic resonance, scanning electron microscope, and optical profilometry techniques. Our results indicate that soaking with Sc-CO2 will dramatically increase the shale fracture permeability and aperture due to the calcite and dolomite dissolution. This free-face dissolution process will remove the mineral particles in the fracture surface, resulting in larger pores, peaks, and valleys in the fracture surfaces. This process may last for seven days, and after that, chemical reactions may terminate, and the rock-Sc-CO2 system turns stable. Our results explain how Sc-CO2 alters the shale fracture permeability through the chemical dissolution of specific minerals from a microscale analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] Accessibility to quality and clean water has in recent times been compromised due to the presence of pollutants, thus posing as a threat to the survival of living organisms. The adsorption technique in this regard has been observed to be useful in the remediation process with the material used as the adsorbent playing an integral role. In this study, a novel biocomposite (PN-Fe 3 O 4 -IDA-Al) based on peanut husk (a low-cost material) was developed by functionalization with aluminum (Al), iminodiacetic acid (IDA) and Fe 3 O 4. The efficiency of PN-Fe 3 O 4 -IDA-Al as an adsorbent for the remediation of wastewater was evaluated using Congo red (CR) and phosphates (PO 4 3−) as model pollutants. The results from the characterization studies confirmed PN-Fe 3 O 4 -IDA-Al to have superparamagnetic properties which ensures its easy retrieval. Adsorption studies indicated that PN-Fe 3 O 4 -IDA-Al had a maximum monolayer capacity of 79.0 ± 2.0 and 16.8 ± 2.5 mg g−1 for CR and PO 4 3− (according to P), respectively, which was significantly dependent on factors such as reaction time, solution pH, temperature and the presence of some common anions. The Freundlich model was observed to better describe both adsorption processes with chemisorption being the principal underlying mechanism. Results from using real water samples confirmed PN-Fe 3 O 4 -IDA-Al to be highly efficient for practical remediation processes. These results coupled with the synthesis of PN-Fe 3 O 4 -IDA-Al under benign conditions using low-cost materials help to expound the knowledge on the use of low cost materials as the basis for the development of highly efficient adsorbents for wastewater remediation. [ABSTRACT FROM AUTHOR]

Marine sedimentation rate and bottom-water O2 concentration control organic carbon remineralization and sequestration across continental margins, but whether and how they shape microbiome architecture (the ultimate effector of all biogeochemical phenomena) across shelf and slope sediments is still unclear. Here we reveal distinct microbiome structures and functions, amidst comparable pore fluid chemistries, along 300 cm sediment horizons underlying the seasonal (shallow coastal; water depth: 31 m) and perennial (deep sea; water depths: 530 and 580 m) oxygen minimum zones (OMZs) of the Arabian Sea, situated across the western Indian margin. The sedimentary geomicrobiology was elucidated by analyzing metagenomes, metatranscriptomes, enrichment cultures, and depositional rates measured via radiocarbon and lead excess dating; the findings were then evaluated in light of the other geochemical data available for the cores. Along the perennial-OMZ sediment cores, microbial communities were dominated by Gammaproteobacteria and Alphaproteobacteria , but in the seasonal-OMZ core communities were dominated by Euryarchaeota and Firmicutes. As a perennial-OMZ signature, a cryptic methane production–consumption cycle was found to operate near the sediment surface, within the sulfate reduction zone; overall diversity, as well as the relative abundances of anaerobes requiring simple fatty acids (methanogens, anaerobic methane oxidizers, sulfate reducers, and acetogens), peaked in the topmost sediment layer and then declined via synchronized fluctuations until the sulfate–methane transition zone was reached. The microbiome profile was completely reversed in the seasonal-OMZ sediment horizon. In the perennial-OMZ sediments, deposited organic carbon was higher in concentration and rich in marine components that degrade readily to simple fatty acids; simultaneously, lower sedimentation rate afforded higher O2 exposure time for organic matter degradation despite perennial hypoxia in the bottom water. The resultant abundance of reduced carbon substrates eventually sustained multiple inter-competing microbial processes in the upper sediment layers. The entire geomicrobial scenario was opposite in the sediments of the seasonal OMZ. These findings create a microbiological baseline for understanding carbon–sulfur cycling in distinct depositional settings and water column oxygenation regimes across the continental margins. [ABSTRACT FROM AUTHOR]

Covalent modification cycles (CMCs) are basic units of signaling systems and their properties are well understood. However, their behavior has been mostly characterized in situations where the substrate is in excess over the modifying enzymes. Experimental data on protein abundance suggest that the enzymes and their target proteins are present in comparable concentrations, leading to substrate sequestration by the enzymes. In this enzyme-in-excess regime, CMCs have been shown to exhibit signal termination, the ability of the product to return to a stationary value lower than its peak in response to constant stimulation, while this stimulation is still active, with possible implications for the ability of systems to adapt to environmental inputs. We characterize the conditions leading to signal termination in CMCs in the enzyme-in-excess regime. We also demonstrate that this behavior leads to a preferred frequency response (band-pass filters) when the cycle is subjected to periodic stimulation, whereas the literature reports that CMCs investigated so far behave as low-pass filters. We characterize the relationship between signal termination and the preferred frequency response to periodic inputs and we explore the dynamic mechanism underlying these phenomena. Finally, we describe how the behavior of CMCs is reflected in similar types of responses in the cascades of which they are part. Evidence of protein abundance in vivo shows that enzymes and substrates are present in comparable concentrations, thus suggesting that signal termination and frequency-preference response to periodic inputs are also important dynamic features of cell signaling systems, which have been overlooked. [ABSTRACT FROM AUTHOR]

Background: Oilseed rape (B. napus L.) has great potential for phytoremediation of cadmium (Cd)-polluted soils due to its large plant biomass production and strong metal accumulation. Soil properties and the presence of other soluble compounds or ions, cause a heterogeneous distribution of Cd. Results: The aim of our study was to reveal the differential responses of B. napus to different Cd abundances. Herein, we found that high Cd (50 μM) severely inhibited the growth of B. napus, which was not repressed by low Cd (0.50 μM) under hydroponic culture system. ICP-MS assays showed that the Cd2+ concentrations in both shoots and roots under 50 μM Cd were over 10 times higher than those under 0.50 μM Cd. Under low Cd, the concentrations of only shoot Ca2+/Mn2+ and root Mn2+ were obviously changed (both reduced); under high Cd, the concentrations of most cations assayed were significantly altered in both shoots and roots except root Ca2+ and Mg2+. High-throughput transcriptomic profiling revealed a total of 18,021 and 1408 differentially expressed genes under high Cd and low Cd conditions, respectively. The biological categories related to the biosynthesis of plant cell wall components and response to external stimulus were over-accumulated under low Cd, whereas the terms involving photosynthesis, nitrogen transport and response, and cellular metal ion homeostasis were highly enriched under high Cd. Differential expression of the transporters responsible for Cd uptake (NRAMPs), transport (IRTs and ZIPs), sequestration (HMAs, ABCs, and CAXs), and detoxification (MTPs, PCR, MTs, and PCSs), and some other essential nutrient transporters were investigated, and gene co-expression network analysis revealed the core members of these Cd transporters. Some Cd transporter genes, especially NRAMPs and IRTs, showed opposite responsive patterns between high Cd and low Cd conditions. Conclusions: Our findings would enrich our understanding of the interaction between essential nutrients and Cd, and might also provide suitable gene resources and important implications for the genetic improvement of plant Cd accumulation and resistance through molecular engineering of these core genes under varying Cd abundances in soils. [ABSTRACT FROM AUTHOR]

Multi-scale macroalgae growth models are required for the efficient design of sustainable, economically viable, and environmentally safe farms. Here, we develop a multi-scale model for Ulva sp. macroalgae growth and nitrogen sequestration in an intensive cultivation farm, regulated by temperature, light, and nutrients. The model incorporates a range of scales by incorporating spatial effects in two steps: light extinction at the reactor scale (1 m) and nutrient absorption at the farm scale (1 km). The model was validated on real data from an experimental reactor installed in the sea. Biomass production rates, chemical compositions, and nitrogen removal were simulated under different seasons, levels of dilution in the environment and water-exchange rate in the reactor. This multi-scale model provides an important tool for environmental authorities and seaweed farmers who desire to upscale to large bioremediation and/or macroalgae biomass production farms, thus promoting the marine sustainable development and the macroalgae-based bioeconomy. Zollmann et al. develop a multi-scale model for Ulva sp. macroalgae growth, biochemical composition, and nitrogen sequestration, regulated by temperature, light and nutrients. Their results demonstrate that this model can be used to design environmentally friendly and economically sustainable seaweed farms. [ABSTRACT FROM AUTHOR]

The article discusses research which investigated the surface liquid water loss and crustal hydration in planet Mars. Topics explored include the volcanic degassing, atmospheric escape, and crustal hydration simulations performed, the spacecraft measurements of atmospheric water loss, and the calculation of parameter values such as the size of exchangeable reservoir, rate of water drawdown, and rate of volcanic degassing.

[Display omitted] • Iron shavings/O 2 endow detoxification of Sb(III) and direct sequestration of Sb(V). • Fe(0) activated dissolved oxygen to generate •OH without external oxidants. • Sb(III) was oxidized to Sb(V) under the synergistic effect of •OH and Fe(III). • The iron (hydr)oxides sequestered Sb(V) via complexation and co-precipitation. • A facile and sustainable iron-based material was developed for Sb removal in PDW. Trivalent antimonite (Sb(III)) and pentavalent antimonate (Sb(V)) prevail in printing and dyeing wastewater (PDW). Conventional iron-based materials such as iron flocculant and nanoscale zerovalent iron (NZVI) suffer from lack of oxidative capability and agglomerative deactivation for Sb removal, respectively. Herein, this study proposed a dual-function iron shavings coupling aeration system (iron shavings/O 2) for the "oxidation-sequestration" of Sb(III) and the direct sequestration of Sb(V). Results collectively demonstrated that iron shavings/O 2 system performed effectively in a broad solution chemistry environment, including wide pH range, co-existing inorganic ions, organic compounds and even practical water matrices. Fe(0), the primary constituent of iron shavings, activated dissolved oxygen (DO) to •OH through electron transfer (O 2 → O 2 •− → H 2 O 2 → •OH), while it was oxidized to Fe(II) and Fe(III). The generated •OH and Fe(III) synergistically oxidized Sb(III) to less toxic Sb(V), which was then sequestered by iron (hydr)oxides and newly formed iron muds via inner sphere complexation and co-precipitation. Furthermore, the proposed system exhibited stable and efficient Sb removal in a continuous flow reactor. Overall, this work illustrates iron shavings/O 2 is a promising alternative for mainstream iron-based materials towards Sb removal and offers enormous potential for practical PDW treatment. [ABSTRACT FROM AUTHOR]

This study reported a new strategy for enhanced Pb2+ and Cu2+ sequestration by Artemia cyst shell (shell) supported nano-Mg from aqueous solutions and the carbonated exhausted-adsorbents sequenced potential application in photo-catalyst, which obtained two expected results. One is that the immobilization of nano-Mg onto Artemia cyst shell (shell-Mg) can greatly strengthen the adsorption effect of the neat cyst shell on Pb2+ and Cu2+. The adsorption capacities of shell-Mg for both metal ions reached to 622.01 and 313.91 mg/g, which was 10–15 and 30–50 times that of the neat shell respectively. And shell-Mg has strong selectivity, which was approximately 2–4 times that of shell. The shell-Mg can be used to retrieve Pb2+ and Cu2+ from aqueous solutions efficiently. Another is that the carbonated exhausted-adsorbents (C-shell-Mg-Pb and C-shell-Mg-Cu) showed their potential photocatalytic degradation effects on congo red under pH = 4 condition, the decolorization rate reached to 61.19% and 80.39% respectively. Reuse of exhausted adsorbents can avoid the secondary pollution caused by the regeneration, extend the utilization value of exhausted adsorbents, and provide a new viewpoint for the reuse of spent bio-nanomaterial adsorbents. [Display omitted] • The sequestration of Pb2+ and Cu2+ can be enhanced by Artemia cyst shell supported nano-Mg composite. • The carbonized exhausted-adsorbent has the potential photocatalytic performance. • Reuse of exhausted adsorbent can avoid the secondary pollution caused by the regeneration. • The extension test for potential photocatalytic performance of exhausted adsorbent provides a new way for the reuse of spent bio-adsorbents. [ABSTRACT FROM AUTHOR]

Reactive transport plays an important role in various subsurface applications, including carbon dioxide sequestration, nuclear waste storage, biogeochemistry and the simulation of hydro–thermal reservoirs. The model couples a set of partial differential equations, describing the transport of chemical species, to nonlinear algebraic or differential equations, describing the chemical reactions. Solution methods for the resulting large nonlinear system can be either fully coupled or can iterate between transport and chemistry. This paper extends previous work by the authors where an approach based on the Newton–Krylov method applied to a reduced system has been developed. The main feature of the approach is to solve the nonlinear system in a fully coupled manner while keeping transport and chemistry modules separate. Here we extend the method in two directions. First, we take into account mineral precipitation and dissolution reactions by using an interior point Newton method, so as to avoid the usual combinatorial approach. Second, we study two-dimensional heterogeneous geometries. We show how the method can make use of an existing transport solver, used as a black box. We detail the methods and algorithms for the individual modules, and for the coupling step. We show the performance of the method on synthetic examples. [ABSTRACT FROM AUTHOR]

Preorganization is a basic design principle used by nature that allows for synergistic pathways to be expressed. Herein, a full account of the conceptual and experimental development from randomly distributed functionalities to a convergent arrangement that facilitates cooperative binding is given, thus conferring exceptional affinity toward the analyte of interest. The resulting material with chelating groups populated adjacently in a spatially locked manner displays up to two orders of magnitude improvement compared to a random and isolated manner using uranium sequestration as a model application. This adsorbent shows exceptional extraction efficiencies, capable of reducing the uranium concentration from 5 ppm to less than 1 ppb within 10 min, even though the system is permeated with high concentrations of competing ions. The efficiency is further supported by its ability to extract uranium from seawater with an uptake capability of 5.01 mg g−1, placing it among the highest‐capacity seawater uranium extraction materials described to date. The concept presented here uncovers a new paradigm in the design of efficient sorbent materials by manipulating the spatial distribution to amplify the cooperation of functions. [ABSTRACT FROM AUTHOR]

Permanently shadowed regions (PSRs) at the lunar poles are of unique interest for science and exploration due to their low surface temperatures and potential for volatile sequestration. While not directly illuminated by the Sun, PSRs are exposed to faint sources of radiation such as starlight, Lyman alpha photons from the interplanetary medium, and sunlight scattered from the surrounding topography. These illumination sources are significant as they contribute to the thermal energy budget of PSRs, and also provide a photon source with which to observe areas otherwise obscured by shadow. In this work, we survey the illumination conditions from the aforementioned sources within northern and southern hemisphere PSRs at far ultraviolet (FUV), visible (vis) and infrared (IR) wavelengths. With respect to magnitude, it is shown that scattered sunlight is the brightest radiation source to reach the PSRs in the visible and IR spectral regimes. As well, we show that scattered sunlight contributes a considerable supply of FUV photons, and may exceed the interplanetary medium/starlight brightness in many PSR craters due to the temporal and spatial variance of scattered sunlight. This finding suggests a higher rate of photodesorption and lower adsorption residence times for water molecules than previously suggested, and, furthermore, indicates that this rate fluctuates diurnally, seasonally and geographically owing to the variability of the incoming solar flux. Large differences in the received solar energy are found between craters, with crater latitude and size being among the modulating influences. Within individual craters, strong spatial heterogeneities in scattered solar flux are found, with equator-facing PSR slopes receiving 40%–60% of the total energy of slopes oriented toward the pole. Finally, we show that the radiation available is sufficient to detect water ice using vis/FUV or vis/IR filter pairings, and such observations can be made with signal to noise > 10 with an FUV-sensitive camera; however, with more scattered solar photons available for IR imaging, higher signal to noise ratios can be attained with a vis/IR filter pairing. • Scattered sunlight is mapped within lunar PSRs at FUV, vis and IR wavelengths. • As modeled, scattered sunlight supplies an appreciable flux of FUV photons to PSRs. • FUV scattered solar irradiation will contribute to photodesorption in PSRs. • The upwelling radiation from PSR surfaces is sufficient for water ice prospecting. • Enhanced SNR can be attained with vis/IR filter pairing. [ABSTRACT FROM AUTHOR]

The potential of CO2 sequestration in salt mine cavities formed following salt extraction by dissolution is one of current trends considered to reduce CO2 emissions in the atmosphere, which can contribute to mitigating climate change. Research carried out by modelling and simulation of CO2 sequestration trough a case study involving the salt mine at Târgu Ocna has identified the possible risks rising from gas leakage. [ABSTRACT FROM AUTHOR]

The article informs about how disordered proteins are challenging therapeutic targets, and no drug is in clinical use that modifies the properties of their monomeric states. Topics include how aggregation of the amyloid-β (Aβ) peptide in brain tissue is one of the hallmarks of Alzheimer's disease; and how Aβ involves a complex nonlinear network of interdependent microscopic processes, including primary nucleation, elongation, and secondary nucleation.

Several insect species have evolved two‐component chemical defences that enable the rapid release of deterrent or toxic metabolites upon predator attack. However, whether these chemical defences vary across insect ontogeny and how this affects the predation risk of different life stages has rarely been addressed.The horseradish flea beetle Phyllotreta armoraciae possesses a two‐component chemical defence that consists of sequestered glucosinolates and an insect myrosinase capable of converting the non‐toxic glucosinolates to deterrent isothiocyanates. Here, we show that the levels of sequestered glucosinolates only varied 2‐fold across beetle ontogeny, but that insect myrosinase activity differed up to 43‐fold among ontogenetic stages.Specifically, glucosinolate levels were 1.5‐fold lower in the larvae of P. armoraciae than in pupae, but they showed 43.4‐fold higher levels of myrosinase activity. Consistent with the distinct levels of myrosinase activity in larvae and pupae, only larvae released high amounts of toxic isothiocyanates when they were attacked by the generalist predator Harmonia axyridis. P. armoraciae larvae deterred the predator and survived one attack, whereas pupae were killed.Feeding of P. armoraciae larvae on plants that differed in glucosinolates and plant myrosinase activity influenced the accumulation of glucosinolates in larvae and their subsequent interaction with H. axyridis. Larvae with low levels of sequestered glucosinolates were much more susceptible to predation than larvae containing high glucosinolate levels.Our results demonstrate that sequestered plant defence metabolites selectively protect specific ontogenetic stages of P. armoraciae from predation. The strong influence of plant defensive chemistry on sequestration indicates that predators have played an important role in the evolution of host use in this specialist herbivore. The distinct life styles of flea beetle life stages and their strategies to prevent predation by biologically relevant predator communities deserve further investigations. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Gas diffusion-sorption is a critical step in coalbed methane (CBM) exploitation and carbon dioxide sequestration. Because of the particularity of gas physical properties, it is difficult to visualize the gas diffusion-sorption process in coal by experimental methods. Due to the limitation of experimental approaches to image the three-dimensional coal pore structure, it is impossible to obtain the three-dimensional pore structure images of coal. As a result, the visualization of gas diffusion-sorption in coal pore structure by numerical ways is impossible. In this study, gas diffusion coefficients were firstly estimated by experiments. Then, a gas diffusion-sorption coupled model was developed which can be applied to the nanoscale geometry imaged by synchrotron radiation nano-CT. The dynamic process of gas diffusion and ad-/desorption in the nanoscale microstructure of coal was visualized by the developed gas diffusion-adsorption coupled model and the numerical simulation based on MATLAB. The simulation results show a good agreement with the experimental results. The gas diffusion-sorption coupled model and numerical method can help to investigate the effect of microstructure on gas diffusion and ad-/desorption and provides a possibility to investigate the multiscale gas transportation and adsorption in coal pore-fracture system. [ABSTRACT FROM AUTHOR]

This study investigates the sorption of a non-steroidal anti-inflammatory drug, ibuprofen, (IBP) using acid activated carbon prepared from orange peel (OPA). OPA was characterized via the use of Fourier transform infrared and scanning electron microscopy techniques. Four isotherm models were utilized to assess the adsorption data: Langmuir, Freundlich, Temkin, and Dubinin–Raduskevich, respectively. It was established that the IBP adsorption onto OPA fitted Langmuir isotherm model most. The optimum monolayer adsorption capacity of OPA was 49.30 mg/g at 50 °C. The adsorption data was subjected to kinetic test using pseudo-first-order and pseudo-second-order, Elovich, and intraparticle diffusion models. The sorption process was best described by pseudo-second-order kinetic model. The mean heat of adsorption, Ea at all temperatures studied was < 8.00 kJmol−1, signifying that the sorption mechanism is physisorption. Thermodynamic study reveals that the adsorption is spontaneous and exothermic. OPA was established to be a viable and effective adsorbent for the sorption of IBP from aqueous medium. [ABSTRACT FROM AUTHOR]

Plants trigger immune responses upon recognition of fungal cell wall chitin, followed by the release of various antimicrobials, including chitinase enzymes that hydrolyze chitin. In turn, many fungal pathogens secrete LysM effectors that prevent chitin recognition by the host through scavenging of chitin oligomers. We previously showed that intrachain LysM dimerization of the Cladosporium fulvum effector Ecp6 confers an ultrahigh-affinity binding groove that competitively sequesters chitin oligomers from host immune receptors. Additionally, particular LysM effectors are found to protect fungal hyphae against chitinase hydrolysis during host colonization. However, the molecular basis for the protection of fungal cell walls against hydrolysis remained unclear. Here, we determined a crystal structure of the single LysM domain-containing effector Mg1LysM of the wheat pathogen Zymoseptoria tritici and reveal that Mg1LysM is involved in the formation of two kinds of dimers; a chitin-dependent dimer as well as a chitin-independent homodimer. In this manner, Mg1LysM gains the capacity to form a supramolecular structure by chitin-induced oligomerization of chitin-independent Mg1LysM homodimers, a property that confers protection to fungal cell walls against host chitinases. Author summary: Chitin plays a central role in plant-fungi interactions, since it is a major component of the fungal cell wall that is targeted by host hydrolytic enzymes to inhibit the growth of fungal pathogens on the one hand, and release chitin fragments that are recognized by host immune receptors to activate further immune responses on the other hand. In turn, many fungal pathogens secrete chitin binding LysM effectors to which currently two functions have been assigned. Most LysM effectors that were functionally characterized to date function to prevent chitin recognition by host immune receptors through chitin sequestration. Additionally, some LysM effectors were shown to protect fungal hyphae against hydrolysis by host chitinases. The crystal structure of Mg1LysM from the Septoria blotch pathogen of wheat, Zymoseptoria tritici, revealed that chitin-induced dimerization of two Mg1LysM protomers through high affinity binding is required for hyphal protection against chitinases. Since Mg1LysM also forms ligand-independent homodimers, a supramolecular structure can be formed in which chitin-induced oligomerization of Mg1LysM ligand-independent homodimers form a contiguous Mg1LysM higher ordered structure that is anchored to the chitin in the fungal cell wall to prevent hydrolysis by host chitinases. [ABSTRACT FROM AUTHOR]

In this study, the potential for pulverized raw macadamia nut shell (MNS) for the sequestration of methylene blue from aqueous media was assessed. The sorbent was characterized using scanning electron microscopy for surface morphology, functional group analysis was performed with a Fourier-transform infrared spectrometer (FT-IR), and Brunauer–Emmett–Teller (BET) isotherm was used for surface area elucidation. The effects of contact time, sorbent dosage, particle size, pH, and change in a solution matrix were studied. Equilibrium data were fitted using Temkin, Langmuir, and Freundlich adsorption isotherm models. The sorption kinetics was studied using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The feasibility of the study was established from the thermodynamic studies. A surface area of 2.763 m2/g was obtained. The equilibrium and kinetics of sorption was best described by the Langmuir and the pseudo-second-order models, respectively. The sorption process was spontaneous (− Δ G 0 = 28.72 − 31.77 kJ / mol) and endothermic in nature (Δ H 0 = 17.45 kJ / mol). The positive value of Δ S 0 (0.15 kJ / mol K) implies increased randomness of the sorbate molecules at the surface of the sorbent. This study presents sustainable management of wastewater using MNS as a potential low-cost sorbent for dye decontamination from aqueous solution. [ABSTRACT FROM AUTHOR]

Since the 1990s the Mekong River delta has suffered a large decline in sediment supply causing coastal erosion, following catchment disturbance through hydropower dam construction and sand extraction. However, our new geological reconstruction of 2500-years of delta shoreline changes show that serious coastal erosion actually started much earlier. Data shows the sandy coast bounding river mouths accreted consistently at a rate of +2 to +4 km2/year. In contrast, we identified a variable accretion rate of the muddy deltaic protrusion at Camau; it was < +1 km2/year before 1400 years ago but increased drastically around 600 years ago, forming the entire Camau Peninsula. This high level of mud supply had sharply declined by the early 20th century after a vast canal network was built on the delta. Since then the Peninsula has been eroding, promoted by the conjunction of mud sequestration in the delta plain driven by expansion of rice cultivation, and hysteresis of long-term muddy sedimentation that left the protrusion exposed to wave erosion. Natural mitigation would require substantial increases in sediment supply well above the pre-1990s levels. [ABSTRACT FROM AUTHOR]

Few studies exist that document how high-elevation Andean ecosystems recover naturally after the cessation of human activities and this can limit the implementation of cost-effective restoration actions. We assessed Andean forest (Polylepis stands) and páramo grassland recovery along an elevation gradient (3,600–4,350 m.a.s.l.) in the Yanacocha Reserve (Ecuador) where natural recovery has been allowed since 1995. Within the Yanacocha Reserve in 2012 and 2014 the aboveground biomass (AGB), aboveground necromass (AGN) and belowground biomass (BGB) carbon (C) stocks were measured and C sequestration rates calculated as proxy of ecosystem recovery. The soil organic carbon (SOC) stock to 36-cm depth was also quantified during the 2012 survey. To explore potential drivers of spatiotemporal variation of the forest and páramo C stocks they were related to abiotic and biotic variables. Andean forest C stocks were influenced mainly by disturbance history and tree-species composition. Páramo C stocks´ spatial variation were related to the elevation gradient; we found a positive significant trend in páramo AGB-C stocks with elevation, whereas we found a significant negative trend in AGN-C stocks. Likewise, significant temporal changes were found for AGB-C and AGN-C stocks. Net increases in AGB-C stocks were the largest in the Andean forest and páramo, 2.5 Mg C ha-1 year-1 and 1.5 Mg C ha-1 year-1 respectively. Carbon sequestration rates were partly explained by environmental variables. In the Andean forest, plots with low dominance of Baccharis padifolia were observed to present higher AGB-C and lower BGB-C sequestration rates. In the páramo, higher sequestration rates for AGB-C were found at higher elevations and associated with higher levels of growth-forms diversity. Temporal changes in BGB-C stocks on the contrary were non-significant. Our results indicated that terrestrial aboveground C sequestration rates might be an appropriate indicator for assessing Andean forest and páramo recovery after human disturbance. [ABSTRACT FROM AUTHOR]

Glycine N-myristoylation is an essential acylation modification modulating the functions, stability, and membrane association of diverse cytosolic proteins in human cells. Myristoyl-CoA is the 14-carbon acyl donor of the acyltransferase reaction. Acyl-CoAs of a chain length compatible with the binding site of the N-myristoyltransferase enzymes (NMT) are competitive inhibitors, and the mechanism protecting these enzymes from unwanted acyl-CoA species requires the acyl-CoA binding protein ACBD6. The acyl-CoA binding domain (ACB) and the ankyrin-repeat motifs (ANK) of ACBD6 can perform their functions independently. Interaction of ANK with human NMT2 was necessary and sufficient to provide protection. Fusion of the ANK module to the acyl-CoA binding protein ACBD1 was sufficient to confer the NMT-stimulatory property of ACBD6 to the chimera. The ACB domain is dispensable and sequestration of the competitor was not the basis for NMT2 protection. Acyl-CoAs bound to ACB modulate the function of the ANK module and act as positive effector of the allosteric activation of the enzyme. The functional relevance of homozygous mutations in ACBD6 gene, which have not been associated with a disease so far, is presented. Skin-derived fibroblasts of two unrelated individuals with neurodevelopmental disorder and carrying loss of function mutations in the ACBD6 gene were deficient in protein N-myristoylation. These cells were sensitive to substrate analog competing for myristoyl-CoA binding to NMT. These findings account for the requirement of an ANK-containing acyl-CoA binding protein in the cellular mechanism protecting the NMT enzymes and establish that in human cells, ACBD6 supports the N-myristoylation of proteins. [ABSTRACT FROM AUTHOR]

Sulphur dioxide (SO2) is removed from flue gases prior to discharge into the atmosphere by high temperature sulphation reactions with the mineral calcite (CaCO3) in the form of calcite aggregates such as limestone. The efficiency of this industrial-scale process is constrained by the self-inhibiting growth of anhydrite (CaSO4) along calcite grain boundaries. Using very high resolution X-ray μCT and Scanning Electron Microscopy we show, for the first time, how the sulphation reaction is initiated by the anisotropic thermal expansion of calcite grains to produce high inter-grain permeability. In turn fast gas-solid reaction occurs to produce a network of porous anhydrite layers between grains. Individual calcite grains are then free to rotate and translate with respect to each other as the sulphation reaction proceeds. Grain translations of up to 24 μm and rotations of up to 0.64 degrees have been tracked in samples of a highly compacted calcite aggregate (Carrara Marble) across up to 600,000 grains through heating and cooling cycles during exposure to SO2 gas flow at temperatures from 600 to 750 °C at one atmosphere. Such grain kinematics help to maintain gas phase permeability in the solid reactant and mitigate the inhibitory growth of porous anhydrite on grain boundaries. [ABSTRACT FROM AUTHOR]

In shale gas reservoirs, CH4 and CO2 have finite aqueous solubilities at high-pressure conditions and their dissolutions in water affect the determination of the original gas in place and the CO2 sequestration. In addition, the dissolution of CO2 decreases the pH of connate water, and the geochemical reactions may thus occur in carbonate-rich shale reservoirs. The comprehensive simulations of this work quantify the effects of aqueous solubility and geochemistry on the performance CO2 huff-n-puff process in shale gas reservoir. Accounting for the aqueous solubility of CH4 increases the initial natural gas storage and natural gas production. The effect of the aqueous solubility of CO2 enables to sequester additional CO2 via solubility trapping. Considering the geochemical reactions, the application of the CO2 huff-n-puff process causes the dissolution of carbonate minerals and increases the porosity enhancing the gas flow and the gas recovery. Incorporation of geochemistry also predicts the less CO2 sequestration capacity. Therefore, this study recommends the consideration of aqueous solubility and geochemical reactions for the accurate prediction of gas recovery and CO2 sequestration in shale gas reservoirs during the CO2 huff-n-puff process. [ABSTRACT FROM AUTHOR]

The solubility of apatite in anatectic melt plays an important role in controlling the trace-element compositions and isotopic signatures of granites. The compositions of glassy melt inclusions and nanogranitoids in migmatites and granulites are compared with the results of experimental studies of apatite solubility to evaluate the factors that influence apatite behavior during prograde suprasolidus metamorphism and investigate the mechanisms of anatexis in the continental crust. The concentration of phosphorus in glassy melt inclusions and rehomogenized nanogranitoids suggests a strong control of melt aluminosity on apatite solubility in peraluminous granites, which is consistent with existing experimental studies. However, measured concentrations of phosphorus in melt inclusions and nanogranitoids are generally inconsistent with the concentrations expected from apatite solubility expressions based on experimental studies. Using currently available nanogranitoids and glassy melt inclusion compositions, we identify two main groups of inclusions: those trapped at lower temperature and showing the highest measured phosphorus concentrations, and melt inclusions trapped at the highest temperatures having the lowest phosphorus concentrations. The strong inconsistency between measured and experimentally predicted P concentrations in higher temperature samples may relate to apatite exhaustion during the production of large amounts of peraluminous melt at high temperatures. The inconsistency between measured and predicted phosphorus concentrations for the lower-temperature inclusions, however, cannot be explained by problems with the electron microprobe analyses of rehomogenized nanogranitoids and glassy melt inclusions, sequestration of phosphorus in major minerals and/or monazite, shielding or exhaustion of apatite during high-temperature metamorphism, and apatite–melt disequilibrium. The unsuitability of the currently available solubility equations is probably the main cause for the discrepancy between the measured concentrations of phosphorus in nanogranites and those predicted from current apatite solubility expressions. Syn-entrapment processes such as the generation of diffusive boundary layers at the mineral-melt interface may also be responsible for concentrations of P in nanogranitoids and glassy melt inclusions that are higher than those predicted in apatite-saturated melt. [ABSTRACT FROM AUTHOR]

The global fluxes of carbon in the ecosystem of Earth, with particular attention drawn to the cycle of CO2 were characterised. The sequestration of carbon dioxide in the biomass of plants, especially the ones which can be cultivated as catch crops is described. It was shown that the cultivation of catch crops may play an important role in the mitigation of CO2 emissions. [ABSTRACT FROM AUTHOR]

Advanced materials for the efficient treatment of textile wastewater need to be developed for the sustainable growth of the textile industry. In this study, graphene oxide (GO) was modified by the incorporation of natural clay (bentonite) and mixed metal oxide (copper-cobalt oxide) to produce GO-based binary and ternary composites. Two binary composites, GO/bentonite and GO/Cu–Co Ox (oxide), and one ternary composite, GO/bentonite/Cu–Co Ox, were characterized by Fourier transform-infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and Brunauer-Emmett-Teller (BET) analysis. The adsorption efficiency of these composites was evaluated against a cationic dye, Basic Blue 41 (BB41). The composites had several surface functional groups, and the ternary composite had tubular porous structures formed by the cross-linking of the bentonite and GO planes. The BET surface area of the ternary composite was 50% higher than that of the GO. The BB41 removals were 92, 89, 80, and 69% for GO/bentonite/Cu–Co oxide, GO/bentonite, GO and GO/Cu–Co oxide, respectively. The pseudo-2nd-order and intraparticle diffusion models best describe the kinetics results, indicating chemisorption and slow pore diffusion-controlled adsorption processes. The Langmuir isotherm-derived adsorption capacity of GO/bentonite/Cu–Co oxide was 351.1 mg/g, which was very close to the measured value. After five consecutive cycles, the ternary composite retained 90% BB41 removal efficiency compared to its 1st cycle. Electrostatic interaction and pore diffusion were predicted to be the controlling mechanisms for the adsorption of the BB41. The GO-based ternary composite can be a feasible and scalable adsorbent for BB41 in wastewater treatment. [Display omitted] • Graphene oxide (GO) was intercalated into bentonite layers, with crumpled and tubular pore structures. • Carboxylic, hydroxyl, epoxide, and carbonyl groups were present on GO/bentonite/Cu–Co oxide (Ox). • GO/bentonite/Cu–Co Ox has 40 and 50% greater surface area and adsorption capacity than GO. • GO/bentonite/Cu–Co Ox retained ∼90% efficiency after 5 consecutive cycles compared to the 1st cycle. • Kinetics studies: chemical interaction dominated the adsorption process for basic blue 41 (BB41). [ABSTRACT FROM AUTHOR]

This investigation is part of the studies carried out by the Faculty of Technical Sciences, the Agricultural Mechanization Center (CEMA) of the Agrarian University of Havana (UNAH) and the Institute of Animal Science (ICA), on the evaluation of agricultural assemblies for the production of animal feed. It was developed with the objective of determining the energy costs of the Russian BELARUS 510 Tractor and of the Brazilian JF-50 forage chopper. It is determined that the total energy costs depend, to a greater extent, on the energy sequestered in fuel (ESc), with a value of 103,73 MJ/h and 53% as the highest value. The energy sequestered in lubricants and filters (ESl) represented the lowest dependency with a value of 5,19 MJh, being 2,65% the lowest value. Total hourly energy costs (EST) amount to 195,48 MJ/h and energy costs total per unit mass processed (ESt) to 365 MJ/t. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Copper was doped firstly on sulfidated zero valent iron for Cr(VI) sequestration. • SZVI-Cu enhanced Cr(VI) sequestration compared with ZVI, SZVI and ZVI-Cu. • Cr(VI) sequestration efficiency with SZVI-Cu reached 98% in a wide pH range. • Mechanistic analysis revealed sulfidation promoted the release of ferrous iron. Abstract The reactivity of zero valent iron (ZVI) for sequestering Cr(VI) is self-inhibiting in aquatic environments, which limits the application of ZVI. A series of improvement strategies have been proposed. In this study, a copper-sulfidated ZVI (SZVI-Cu) material was prepared by depositing copper onto sulfidation modified ZVI to enhance the sequestration efficiency and capacity of Cr(VI). Comparative experiments were used to demonstrate the superiority of SZVI-Cu for sequestration of Cr(VI) with ZVI, sulfidated ZVI (SZVI) and iron-copper (ZVI-Cu). In addition, SZVI-Cu exhibited a prominent ability for sequestration of Cr(VI) over a wide pH range of 4–8. The sequestration efficiency of Cr(VI) by SZVI-Cu reached 97.9% within 20 min even at pH 8.0, and the sequestration rate of Cr(VI) increased 2.4–59.7 folds compared with other three materials. Batch experiments were also used to evaluate the removal efficiency under various factors such as SZVI-Cu dosage and mixing rate. The positive correlation between the sequestration efficiency of Cr(VI), the produced rate of Fe(II) and the inhibited removal of Cr(VI) in the presence of 1,10-phenanthroline indicated that Fe(II) played an important role to the sequestration of Cr(VI). The mechanism analysis showed that sulfidation can facilitate the electron transfer from iron metal to contaminant and strengthen Fe(II) releasing from ZVI, and loading Cu0 can also be conducive to the production of Fe(II) due to the potential difference between the two metals. Cu combined with ZVI function as galvanic cells not only accelerates the reaction rate but also increases the sequestration capacity of Cr(VI). SZVI-Cu is promising for rapid and effective sequestration of Cr(VI) over a wide pH range. [ABSTRACT FROM AUTHOR]

Efficient sequestration of U(VI) from complex aqueous solution is of vital importance for environmental remediation. In this work, the fully phosphorylated graphene oxide foam (phos-GOF) was synthesized via a facile hydrothermal method and the as-prepared 3D phos-GOF was served as an adsorbent to capture U(VI) from aqueous solution. The introduction of abundant phosphorus-containing groups via phytic acid endows phos-GOF good hydrophilia and excellent affinity for U(VI). The adsorption performance of phos-GOF for U(VI) was carefully evaluated under different environments. phos-GOF shows rapid and high efficiency for U(VI) adsorption. The maximum adsorption capacity of phos-GOF for U(VI) is ∼483 mg/g, which is much higher than that of pristine graphene oxide foam (GOF). In addition, the spent 3D phos-GOF can be easily regenerated by a simple and low-cost desorption process using 0.02 mol/L HNO 3. The interaction mechanism between phos-GOF and U(VI) is mainly attributed to the inner-sphere complexation between phosphoric functional groups and U(VI) based on a series of spectroscopic analyses. The 3D phos-GOF exhibits favorable sequestration performance towards U(VI) which can be used as a potential candidate in uranium-bearing wastewater treatment and disposal. Fully phosphorylated 3D graphene oxide foam for the efficient removal of U(VI). Image 1 • The free-standing 3D phos-GOF was prepared via simple and feasible hydrothermal method. • The maximum adsorption capacity of phos-GOF for U(VI) is ∼483 mg/g. • The adsorption of phos-GOF for U(VI) can be maintained at ∼ 93.5% after five cycles. • Inner-sphere complexation contributes much to the adsorption of phos-GOF towards U(VI). The 3D phos-GOF exhibits rapid and high efficiency for U(VI) sequestration and can be easily separated and regenerated. [ABSTRACT FROM AUTHOR]

Abstract A new polyaminocarboxylic bis-(3-hydroxy-4-pyridinone), derivative of DTPA, DTPA(PrHP) 2 , was synthesized starting from maltol by means of a coupling reaction of a protected 3-hydroxy-4-pyridinone and DTPA bis-anhydride. The DTPA(PrHP) 2 acid-base behavior was investigated by UV–Vis spectrophotometry and spectrofluorimetry at I = 0.15 mol L−1 in NaCl (aq) at T = 298.15 K and T = 310.15 K. To confirm the speciation scheme, also 1H NMR measurements were performed at T = 298.15 K. The protonation constants obtained from the cited different analytical techniques showed good accordance and were also in agreement with data reported in the literature. The complexing ability of DTPA(PrHP) 2 towards divalent (Ca2+, Cu2+, Zn2+) and trivalent (Al3+, Fe3+) cations was studied by potentiometric, UV–Vis spectrophotometric and 1H NMR titrations at T = 298.15 K and I = 0.15 mol L−1 in NaCl (aq). The fitting analysis of experimental data led to the determination of different speciation models consisting of M p L q H r (pn+r-5q) species with different stoichiometry and protonation stages, hydrolytic mixed and polynuclear complexes. The equilibrium model and complex formation constants, obtained from various analytical techniques, are in good agreement. The sequestering ability of the ligand towards the metal cations was assessed through the determination of the pL 0.5 and pM parameters at different pH values and pH = 7.4, respectively, which showed to follow the trend Fe3+ > Al3+ > Cu2+ > Ca2+ > Zn2+. Finally, biodistribution studies were carried out in mice previously injected with the radiotracer 67Ga–citrate to evaluate the in vivo ability of DTPA(PrHP) 2 as chelating agent towards trivalent metal cations. Graphical abstract Metal chelation capacity based on the pM values calculated vs. pH for different Mn+/bis-3-hydroxy-4-pyridinone (DTPA(PrHP) 2) systems; in vivo M3+ sequestration. Unlabelled Image Highlights • A new polyaminocarboxylic bis-(3-hydroxy-4-pyridinone), derived from diethylenetriaminepentaacetic acid, was synthesized. • Its acid-base behavior and complexation towards M2+ and M3+ were investigated. • The sequestering ability of the ligand towards Mn+ was studied using the pL 0.5 parameter determination at different pHs. • The pM values, calculated at physiological pH, follows the trend: Fe3+ > Al3+ > Cu2+ > Ca2+ > Zn2+. • Biodistribution studies indicated that the ligand has high in vivo chelating ability towards trivalent metal cations. [ABSTRACT FROM AUTHOR]

Highlights • High removal and reduction of U(VI) were observed by ZVI/AC and ZVI, respectively. • U(VI) removal on ZVI at pH < 5.0 was enhanced with increasing carbonate. • Redox and adsorption dominated U(VI) removal on ZVI and ZVI/AC, respectively. Abstract Mechanistic investigation of U(VI) removal on zero-valent iron/activated carbon (ZVI/AC) was elucidated by batch, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) techniques. Batch experiments showed that U(VI) removal on ZVI/AC was significantly higher than that of ZVI, whereas the reduction of U(VI) on ZVI was slightly higher than that of ZVI/AC under reaction time of 12 h. No influence of carbonate on U(VI) removal by ZVI/AC was observed at pH < 5.0, whereas U(VI) removal on ZVI at pH < 5.0 was significantly enhanced with increasing carbonate concentration due to the electrostatic attraction of positive charge of ZVI/AC and negative uranyl-carbonate complexes such as UO 2 CO 3 (aq)/UO 2 (CO 3) 2 2− species. The ZVI/AC composites displayed the high adsorption capacity and good recycle performance. The high adsorption performance of AC and strong redox capacity of ZVI were responsible for U(VI) removal by XPS and XANES analysis. The corrosion products of ZVI/AC were transferred from magnetite into goethite with increasing reaction time by analysis of XRD pattern. According to EXAFS analysis, the bonding distance of U-U shell for ZVI was slightly shorter than that of ZVI/AC, indicating that redox and adsorption was mainly interaction mechanism of U(VI) on ZVI and ZVI/AC, respectively. These findings are crucial for the application of ZVI-based composites for U(VI) removal in actual environmental remediation. [ABSTRACT FROM AUTHOR]

Abstract An efficient and easy-made material for elimination of radioactive pollution from environment is highly desirable while remains challenging. Herein, porous carbon material (PC) was fabricated by hydrothermal carbonization method for radionuclide adsorption. The characterization revealed that PC had a large amount of micropores with an average size of 100–200 nm. The adsorption mechanism of Eu(III) on PC were explored by batch and spectroscopic techniques. Batch experiments showed that Eu(III) adsorption onto PC was independent of ionic strength, indicating the formation of inner-sphere surface complexes. The maximum adsorption capacity of PC calculated from Langmuir model were 28.6 mg·g−1 for Eu(III) at pH 6.0. FT-IR and XPS analysis revealed that the interaction of Eu(III) onto PC was mainly ascribed to the surface complexation and/or electrostatic interaction of Eu(III) and hydroxyl groups. This work indicated that PC can be regarded as a promising adsorbent for rapid and efficient sequestration of Eu(III) from aqueous solution. Highlights • PC was successfully fabricated by hydrothermal carbonization method. • Eu(III) sorption onto PC was inner-sphere surface complexes. • 28.6mg·g−1 for Eu(III) at pH 6.0. • Surface complexation and/or electrostatic interaction dominated Eu(III) sorption. • PC can be regarded as a promising adsorbent for sequestration of Eu(III). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The N 2 O hydrate formation behavior in porous sediments is followed through MRI. • A sufficient contact between gas and water is crucial for hydrate formation. • A moderate initial P followed by a pressurization are suggested for sequestration. Abstract Increasing nitrous oxide (N 2 O) emissions and their potential impacts on the ozone layer are of worldwide concern. Hydrate-based sequestration technology is considered to be a promising method for N 2 O control. This study investigated the conditions required for N 2 O sequestration through forming hydrates. Magnetic resonance imagining (MRI) was used to capture and quantify N 2 O hydrate formation in porous media simulated by fine quartz sands. The effect of the sequestration conditions on hydrate formation were investigated, involving pressure (1.5, 2, and 2.5 MPa), temperature (275.15, 276.15, and 277.15 K) and initial water saturation (25.06, 33.23, 42.13, and 50.81%). The results indicated the inhomogeneous formation and distribution of N 2 O hydrates in pore spaces. Initial water saturation and pressure were found to significantly impact the hydrate distribution during the initial formation stage. Moreover, N 2 O hydrates formed more rapidly in sediments with a lower water saturation and temperature, indicating that sufficient contact between gas and water and a higher driving force are crucial for abundant hydrate formation. A higher initial water saturation could help improve the sequestration efficiency, which would play a crucial role in locating the sequestration site. This work could provide some insights of the mechanism of N 2 O sequestration via hydrate formation in sediments, making contributions to potential applications in field tests. [ABSTRACT FROM AUTHOR]

Different strategies for treatment and prevention of Alzheimer's disease (AD) are currently under investigation, including passive immunization with anti-amyloid β (anti-Aβ) monoclonal antibodies (mAbs). Here, we investigate the therapeutic potential of a novel type of Aβ-targeting agent based on an affibody molecule with fundamentally different properties to mAbs. We generated a therapeutic candidate, denoted ZSYM73-albumin-binding domain (ABD; 16.8 kDa), by genetic linkage of the dimeric ZSYM73 affibody for sequestering of monomeric Aβ-peptides and an ABD for extension of its in vivo half-life. Amyloid precursor protein (APP)/PS1 transgenic AD mice were administered with ZSYM73-ABD, followed by behavioral examination and immunohistochemistry. Results demonstrated rescued cognitive functions and significantly lower amyloid burden in the treated animals compared to controls. No toxicological symptoms or immunology-related side-effects were observed. To our knowledge, this is the first reported in vivo investigation of a systemically delivered scaffold protein against monomeric Aβ, demonstrating a therapeutic potential for prevention of AD. [ABSTRACT FROM AUTHOR]

Summary: Although a requirement for boron is a well‐established feature of vascular plants, its designation, for almost a century, as essential is challenged and, instead, the proposal is made that it has never been so as conventionally defined. This is because an alternative interpretation of published evidence negates its compliance with one of the criteria for essentiality, that its effects are direct. The alternative, here postulated, is that boron is, and always has been, potentially toxic, a feature which, for normal growth, development and reproduction, needed to be nullified. This was enabled by exploitation of boron's ability to be chemically bound to compounds with cis‐hydroxyl groups. Although particular cell wall carbohydrate polymers, glycoproteins and membrane glycolipids are among candidates for this role, it is here proposed that soluble phenolic metabolites of, or related to, the components of the pathway of lignin biosynthesis, themselves potentially toxic, are primarily used by vascular plants. When metabolic circumstances allow these phenolics to accumulate endogenously in the cytoplasm, their own inherent toxicity is also alleviated, partially at least, by formation of complexes with boron. This chemical reciprocity, enhanced by physical sequestration of the complexes in vacuoles and/or apoplast, thus achieves, in a flexible but indirect manner, a minimization of the inherent toxicities of both boron and relevant phenolics. In these ways, the multifarious outcomes of impairments, natural or experimental, to this interplay are responsible for the lack of consensus to explain the diverse effects observed in the many searches for boron's primary metabolic role, here considered to be nonexistent. In particular, since a toxic element cannot have 'deficiency symptoms', those previously so‐called are postulated to be largely due to the expressed toxicity of phenylpropanoids. A principal requirement for the otherwise toxic boron is to nullify, by means of its indirect chemical and physical sequestration, such expression. In these ways, it is therefore neither an essential nor a beneficial element as currently strictly defined. [ABSTRACT FROM AUTHOR]