Types Of Ions Research Articles

Nanoindentation and deformation behaviors of α$\alpha$‐Al2O3${\rm Al}_2 {\rm O}_3$: A molecular dynamic study

AbstractStudying the nanoindentation behavior of materials at the atomic level is crucial for advancing technologies involving energetic atom bombardment, ion implantation, and nanomechanical testing. Using molecular dynamics simulations with two typical rigid ion interatomic potentials (fixed charges), we showed that the mechanical responses and dislocation nucleation of alumina (‐) are highly temperature‐ and orientation‐dependent. The complex behavior in dislocation dynamics has been rationalized by computing the distribution of stacking fault energy. It is further found that SHIK potential provides better accuracy in describing dislocation dynamics at a much lower computational cost.

Fiber Fabry–Perot Sensor Based on Ion-Imprinted Sodium Alginate/Graphene Oxide Hydrogel for Copper Ion Detection Using Vernier Effect

This work proposes an optical fiber copper ion sensor, which is fabricated by an ion-imprinted sodium alginate/graphene oxide (SA/GO) hydrogel and single-mode fiber (SMF). This sensing Fabry–Perot Interferometer (FPI) achieves −1.98 nm/(mg/L) sensitivity with 0.998 linearity. To achieve higher sensitivity, we add a reference FPI to create a Vernier effect. We achieve 19.58 nm/mg/L sensitivity and 0.989 linearity at a concentration range of 0 mg/L–1.4 mg/L. It was 9.9 times higher than that of a single-sensing FPI. The experimental results also demonstrate that when the FSR values of two FPIs are closer, the higher response sensitivity is achieved. The sensor also has good measurement repeatability and dynamic response. In addition, the experimental results of response selectivity show that its response sensitivity to copper ions is significantly higher than other six types of ions, including iron ions, lead ions, magnesium ions, manganese ion, zinc ions, chromium ions. The copper ion is also mixed with six types of ions to deeply investigate the response selectivity. Good response selectivity and cross-responding are demonstrated by experimental results.

Computational simulation of primary damage in silicon carbide under ions irradiation

Silicon carbide (SiC) and its composites are promising structural materials for advanced nuclear energy applications. Due to the lack of advanced nuclear energy devices, ion beam irradiation is widely used to emulate reactor neutron irradiation. At the same time, different types of ion beam irradiation could produce different primary knock-on atom (PKA) energy spectra. PKA energy determines cascade damage sizes and defect clustering distributions, which may influence the irradiated materials’ long-term microstructural evolution and mechanical properties. This work used SRIM and Geant4 software to investigate the PKA characteristic produced by 1 MeV different noble gas ions and neutrons in the silicon carbide. The PKA energy spectra and weighted energy spectra of C and Si are calculated, respectively. The simulation results show that the PKA energy spectra calculated by the two kinds of software have obvious differences, but the weighted average PKA energies are close to each other. Simulation results verified that the weighted average PKA energy of Kr and Xe ion irradiation is close to that weighted average PKA energy spectrum for neutron irradiation of advanced reactors. The simulation results provide scientific references for understanding the difference in irradiation effects of different types of ions and also provide fundamental bases for the simulation of primary defect damage and long-term defect evolution in irradiated SiC.

Effects of ionic strength, cation type and pH on the cotransport of microplastics with PFOA in saturated porous media.

Both perfluorooctanoic acid (PFOA) and polystyrene microplastics (PS-MPs) are emerging contaminants commonly found in aqueous environments. In co-contaminated areas, MPs may act as carriers for PFOA, complicating transport dynamics. However, information on their cotransport in porous media is limited. This study investigates the transport behaviors of PFOA and PS-MPs in saturated quartz sand columns under varying ionic strength (IS), cation type, and pH. Using the DLVO interaction energy theory and a mathematical model, we analyzed their cotransport. The results demonstrated that PS-MPs inhibited PFOA transport due to hydrophobic adsorption, reducing PFOA mobility. However, at pH 5, PS-MPs facilitated PFOA transport through competitive adsorption on sand surfaces. Conversely, PFOA significantly accelerated PS-MPs transport, likely due to electrostatic repulsion and reduced PS-MPs size. The promoting effect of PFOA on PS-MPs was similar in NaCl and CaCl2 solutions. It is noteworthy that under acidic conditions, the increased electrostatic attraction between PS-MPs and quartz sand leads to substantial adsorption of PS-MPs onto the quartz sand surface. Under these conditions, PFOA exerts almost no promoting effect on PS-MPs. This study showed that the coexistence of PS-MPs and PFOA would influence the mobility of each other in the saturated porous media. Overall, the findings from this work could greatly improve our understanding of cotransport behaviors and environmental risk of PS-MPs and PFOA.

D-Serine disrupts Cbln1 and GluD1 interaction and affects Cbln1-dependent synaptic effects and nocifensive responses in the central amygdala

Ionotropic glutamate receptors (iGluRs) mediate fast excitatory neurotransmission in the nervous system. In addition to NMDA receptor co-agonists, D-serine is a ligand for glutamate delta receptors (GluDs) and interacts with the ligand-binding domain with low affinity. However, D-serine binding does not lead to typical ion channel currents in GluD1 or GluD2 but may contribute to synaptic plasticity. In the developing brain, D-serine binding to GluD2 facilitates long-term depression at parallel fiber-Purkinje cell synapses. However, the influence of D-serine on GluD1's interaction with its amino terminal domain synaptogenic ligand Cbln1 and its subsequent impact on synaptic function and behavior remains unexplored. Here, we found that D-serine inhibited the interaction between Cbln1 and GluD1 in an in vitro cell-binding assay. This effect was concentration-dependent, with an IC50 value of ~ 300 µM. Furthermore, in ex vivo central amygdala (CeA) slices application of recombinant Cbln1 (rCbln1), consistent with its synaptogenic property, produced a robust increase in excitatory neurotransmission and GluD1 expression. This effect of rCbln1 was partially blocked by pre-treatment with D-serine. Finally, in behavioral experiments, we observed that the pro-nociceptive effect of intra-CeA injection of rCbln1 was inhibited by pre-treatment with D-serine. In addition, the antinociceptive effect of intra-CeA rCbln1 injection in an inflammatory pain model was blocked by D-serine. Overall, these results demonstrated that D-serine binding to GluD1 reduces its interaction with Cbln1, which may be relevant to synaptic plasticity and behavior.Graphical

Microwave-assisted synthesis of dual responsive luminomagnetic rare earth metal ions (Nd3+, Dy3+) co-doped nanohydroxyapatite for biomedical applications.

The existing demand for the development of innovative multimodal imaging nanomaterial probes for biomedical applications stems from their unique combination of dual response modalities, i.e., photoluminescence (PL) and magnetic resonance imaging (MRI). In this study, for the first time, neodymium (Nd3+) and dysprosium (Dy3+) rare earth (RE) metal ions were co-doped into a hydroxyapatite (HAp) crystal lattice using a simple microwave-assisted synthesis technique to incorporate the essential properties of both the lanthanides in HAp. Theoretical as well as experimental studies were performed on novel Nd:Dy:HAp nanoparticles (NPs) to understand their photoluminescence and magnetic behaviour. Through co-precipitation, RE (Nd3+, Dy3+) ions were effectively integrated into the HAp crystal lattice, where they preferentially occupied the calcium ion (Ca2+) sites. The as-synthesized HAp, Nd:HAp, Dy:HAp, and Nd:Dy:HAp samples were characterized using different analytical tools. The PL and magnetic characteristics of Nd:Dy:HAp were dependent on the RE dopant ion type and concentration. In comparison with the pure HAp, the RE co-doped (Nd:Dy:HAp) NPs displayed multimodal features due to efficient energy transfer from the Nd3+ (sensitizer) to the Dy3+ (activator) ions. Furthermore, Nd:Dy:HAp NPs had good antimicrobial properties and they also displayed low cell toxicity effects. Hence, Nd:Dy:HAp NPs are attractive biomaterials for PL and MRI applications (e.g. permanent bone and tooth implants) and they can effectively be utilized in the biomedical industry for target-specific drug delivery, bioimaging, functional antimicrobial coatings etc. due to their tunable PL, magnetic, antimicrobial, and biocompatible capabilities.

Multidimensional library for the improved identification of per- and polyfluoroalkyl substances (PFAS)

As the occurrence of human diseases and conditions increase, questions continue to arise about their linkages to chemical exposure, especially for per-and polyfluoroalkyl substances (PFAS). Currently, many chemicals of concern have limited experimental information available for their use in analytical assessments. Here, we aim to increase this knowledge by providing the scientific community with multidimensional characteristics for 175 PFAS and their resulting 281 ion types. Using a platform coupling reversed-phase liquid chromatography (RPLC), electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI), drift tube ion mobility spectrometry (IMS), and mass spectrometry (MS), the retention times, collision cross section (CCS) values, and m/z ratios were determined for all analytes and assembled into an openly available multidimensional dataset. This information will provide the scientific community with essential characteristics to expand analytical assessments of PFAS and augment machine learning training sets for discovering new PFAS.

DisDock: A Deep Learning Method for Metal Ion-Protein Redocking.

The structures of metalloproteins are essential for comprehending their functions and interactions. The breakthrough of AlphaFold has made it possible to predict protein structures with experimental accuracy. However, the type of metal ion that a metalloprotein binds and the binding structure are still not readily available, even with the predicted protein structure. In this study, we present DisDock, a deep learning method for predicting protein-metal docking. DisDock takes distogram of randomly initialized protein-ligand configuration as input and outputs the distogram of the predicted binding complex. It combines the U-net architecture with self-attention modules to enhance model performance. Taking inspiration from the physical principle that atoms in closer proximity display a stronger mutual attraction, this predictor capitalizes on geometric information to uncover latent characteristics indicative of atom interactions. To train our model, we employ a high-quality metalloprotein dataset sourced from the Mother of All Databases (MOAD). Experimental results demonstrate that our approach outperforms other existing methods in prediction accuracy for various types of metal ions.

Altering Lipid A Precursor Ion Types in the Gas Phase for In-Depth Structural Elucidation via Tandem Mass Spectrometry.

Lipid A, a well-known saccharolipid, acts as the inner lipid-glycan anchor of lipopolysaccharides in Gram-negative bacterial cell membranes and functions as an endotoxin. Its structure is composed of two glucosamines with β(1 → 6) linkages and various fatty acyl and phosphate groups. The lipid A structure can be used for the identification of bacterial species, but its complexity poses significant structural characterization challenges. In this work, we present a comprehensive strategy combining condensed-phase sample preparation, electrospray ionization, and gas-phase ion/ion reactions with tandem mass spectrometry for detailed lipid A structural elucidation. We use proton transfer reactions, charge-inversion reactions, and sequential ion/ion reactions for magnesium transfer to generate targeted lipid A ions. The strategy, established with a synthetic monophosphoryl lipid A (MPLA) and known MPLA and diphosphorylated lipid A (DPLA) from Escherichia coli F583, demonstrated that [MPLA - 2H]2-, [MPLA - H]-, and [MPLA - H + Mg]+ precursor ions offer complementary information for MPLA, while [DPLA - H]-, [DPLA + H]+, and [DPLA - H + Mg]+ precursor ions provide analogous information for DPLA analysis. We validated the strategy using known lipid A species and also successfully applied this strategy to profile unknown MPLA and DPLA in the same E. coli strain.

An Atomistic Analysis of the Carpet Growth of KCl Across Step Edges on the Ag(111) Surface.

The carpet growth of alkali halide (AH) layers across step edges of substrates enables the growth of seamless and continuous large domains. Yet, information about how the AH layer adapts continuously to the height difference between the terraces on the two sides of a step is only described by continuum models, which do not give details of the ionic displacements. Here, we present a first study of thin epitaxial KCl(100) layers grown on the Ag(111) surface by scanning tunneling microscopy that provides atomistic details for the first time. Measurements were performed at room temperature. Using a Cl--decorated tip, we resolved the ionic arrangement and hence the KCl lattice distortion in the carpet growth region, in some cases even by imaging both types of ions. Our findings demonstrate the ability of the KCl lattice to distort locally over a short distance of four KCl unit cells as a result of the attractive interaction between the ions and the Ag atoms at and close to the steps. For Ag step edges covered by the KCl carpet, we observe a tendency to straighten along the ⟨110⟩ direction of the KCl layer. In addition, the carpet growth induces the formation of Ag microterraces, i.e., the splitting of higher Ag steps into multiple Ag steps of monatomic height during the KCl deposition at elevated temperatures. These microterraces have a minimum width determined by an energetically preferred fitting to the KCl lattice and allow for the carpet growth, while growth across higher Ag steps is not observed.

Influence of Seven Ion Species on Osteogenic Differentiation of Mesenchymal Stem Cells Stimulated by Macrophages in Indirect and Direct Coculture Systems.

Implanted biomaterials release inorganic ions that trigger inflammatory responses, which recruit immune cells whose biochemical signals affect bone tissue regeneration. In this study, we evaluated how mouse macrophages (RAW264, RAW) and mesenchymal stem cells (KUSA-A1, MSCs) respond to seven types of ions (silicon, calcium, magnesium, zinc, strontium, copper, and cobalt) that reportedly stimulate cells related to bone formation. The collagen synthesis, alkaline phosphatase activity, and osteocalcin production of the MSCs varied by ion dose and type after culture in the secretome of RAW cells. However, DNA production was relatively unaffected. The MSC secretome may also stimulate RAW cells in coculture and, therefore, affect osteogenic differentiation of MSCs. Overall, the ions often exerted different effects on each cell type. This study guides future work that explores the mechanisms behind ion-dependent osteogenic differentiation and cell functions.

Impact of multi-ionic stress on sulfur-based autotrophic denitrification process

Nitrite accumulation poses a significant challenge in treating highly saline nitrogenous wastewater biologically, and the nitrite-based sulfide autotrophic denitrification (NiSAD) process has shown outstanding effectiveness in nitrite removal. Nevertheless, its capacity to withstand salinity in the presence of diverse salt ions remains uncertain. Therefore, this study investigated the individual and combined stresses of NaCl, KCl and MgCl2 on NiSAD process. Denitrification performance was found susceptible to high salinity, and its inhibition was significantly correlated with the type of ions exposed, while IC50 of specific denitrification activity were 5.14% (NaCl), 6.48% (KCl) and 2.03% (MgCl2), respectively. Dual and triple stresses exposure indicate that combined influence of NaCl, KCl and MgCl2 on denitrification performance was characterized by antagonism. Specifically, the order of inhibition intensity was Mg2+>K+>Na+, highlighting the more pronounced impact of ion strength on denitrification inhibition. Metagenomic analysis suggests that the system contains multiple genes associated with osmotic adaptation, indicating its potential for salt tolerance. It would enhance the understanding of the NiSAD process's response to multi-ionic stresses, thereby expanding its potential applications to a wider range of complex salt-containing wastewaters.

Ionophore synthesis for appropriate alkali metal ion extraction and transport

The dynamic character of host-guest chemistry confers the resulting constructions with fascinating stimuli-responsiveness. In the present study, we introduced the synthesized ionophore (podand) in membrane phase to promote the transfer of Na+, K+, Li+ as well as coexisting metal (Na+ and K+) salts. The experiments were performed to study the selectivity of one metal ion over another. To choose the optimal parameter for a specific cation during extraction and transport, a variety of factors were taken into consideration including fluctuation in metal concentration, ionophore structure, type of anion and membrane effect. The results reveal that the concentration and type of ions, membrane type and associated anion alter the extraction and transport process from one phase to another phase.

Effects of alkali activator on the carbonation of one-part alkali-activated nickel slag cement

To study the effects of ion type and dosage of alkali activators on the carbonation of one-part alkali-activated nickel slag (OAANS) mortar, NaOH, Na2SiO3, NaOH+Na2SiO3, KOH, and KOH+Na2CO3 were used as activators. The carbonation depth, compressive strength, and microstructure (via MIP, XRD, and FTIR) were analyzed. Results show that OAANS mortar with K+ as the cation has significantly lower carbonation resistance than those with Na+. Compressive strength with K+ decreases initially after carbonation, then increases, while strength with Na+ grows rapidly early and slows later. With the same cation, mortars with OH− exhibit higher strength than those with SiO 3 2 − after 28 days of carbonation. Increasing alkali dosage promotes hydration, reduces porosity, and enhances carbonation resistance, with effects depending on the alkali activator type.

STUDY OF THE INFLUENCE OF VARIATION OF PHASE COMPOSITION OF COMPOSITE CERAMICS ON RESISTANCE TO RADIATION DAMAGE

The paper presents the results of investigation of the influence of the variation of the phase composition of composite (1−x)Si3N4 – xAl2O3 ceramics on the stability of strength properties in the case of irradiation with heavy ions Xe23+ (230 MeV) at fluences1011–1014 ions/cm2 . The variation of the component concentration was chosen taking into account the possibility of obtaining composite ceramics with different phase ratio: Si3N4, Al2O3, as well as Al2(SiO4)O and SiO2, the formation of which in the composition of ceramics is associated with the processes of thermal decomposition of Si3N4 during high-temperature annealing in an oxygen-containing atmosphere and phase transformations by the type of solid solution formation. The choice of the type of ions for irradiation is conditioned by the possibilities of simulation of structural damage processes leading to unstrengthening of the damaged layer, comparable to the impact of nuclear fuel fission fragments in ceramics – materials of inert matrices of dispersed nuclear fuel. In the course of the conducted studies, it was established that at irradiation fluences of 1011–1012 ion/cm2 structural changes associated with the formation of single isolated structurally deformed inclusions do not lead to significant changes in the strength characteristics of ceramics, while small changes observed are associated with deformation distortions, the accumulation of which leads to destabilization of the damaged layer. In the case of higher irradiation fluences (above1012 ions/cm2 ), which are characterized by the formation of the effects of overlapping defect regions in the damaged layer, the ceramics of 0,4 Si3N4 – 0,6 Al2O3, in which, according to X-ray phase analysis data, the dominant phase is Al2(SiO4)O, the presence of which causes a large number of grain boundaries, which in turn leads to dislocation hardening and restraint of the disordering processes associated with deformation distortions of the damaged layer.

Oscillatory Motion of a Camphor Disk on a Water Phase with an Ionic Liquid Sensitive to Transition Metal Ions.

We investigated oscillatory motion of a camphor disk floating on water containing 5 mM hexylethylenediaminium trifluoroacetate (HHexen-TFA) as an ionic liquid (IL). The frequency of the oscillatory motion increased with increasing concentrations of the transition metal ions Cu2+ and Ni2+ but was insensitive to Na+, Ca2+, and Mg2+, the typical metal ions in the water phase. The surface tension of the water phase containing 5 mM HHexen-TFA also increased with increasing concentrations of Cu2+ and Ni2+ but was insensitive to Na+, Ca2+, and Mg2+. Based on density functional theory, metal-ion species-dependent frequency response is discussed with regard to surface tension as the force of self-propulsion and complex formation between HHexen-TFA and metal ions. These results suggest that complex formation between the transition metal ions (Cu2+, Ni2+) and the ethylenediamine group in the IL increases the surface tension around the camphor disk, resulting in an increase in the frequency of oscillatory motion with increasing concentrations of Cu2+ or Ni2+. The present study suggests that the nature of self-propulsion can be created by complexation, which changes the force of self-propulsion.

Efficient Treatment of Leachate from Municipal Solid Waste Transfer Stations via a Bioreactor–Nanofiltration System: A Pilot-Scale Study

The management of municipal solid waste leachate has emerged as a pivotal challenge in sustainable urban development. Currently, there is limited information on the practical engineering applications of bioreactors and nanofiltration systems on the pilot scale. This work employs a bioreactor–nanofiltration pilot system for the treatment of leachate in municipal solid waste transfer stations. The results demonstrate that the bioreactor–nanofiltration system exhibits excellent and stable efficiency in removing organic pollutants and heavy metal ions. The effluent qualities of COD, TN, and TP are 50, 28, and 2 mg/L, and the removal rates are 99.4%, 99.3%, and 96.1%, respectively. All types of heavy metal ions also comply with the standard limits specified in the “Wastewater quality standards for discharge to municipal sewers” (GB/T 31962-2015). More importantly, using waste materials such as mineralized waste and animal aggregates as bioreactor fillers increases the diversity of the microbial community in the system, and provides an engineering basis for the resource utilization of waste materials. The bioreactor–nanofiltration process is expected to become an ideal solution for the treatment of leachate in transfer stations.

Generation Mechanism of Oxygen Ion Cyclotron Harmonic Waves in the Inner Magnetosphere: Linear Instability Analysis Based on Observations

AbstractLinear kinetic instability analysis based on in situ observations for one typical oxygen ion cyclotron harmonic (OCH) wave event is performed to investigate the wave excitation mechanism. The observed partial‐shell velocity distribution of energetic O+s is fitted by the superposition of multiple ring‐beam distributions. The calculated linear growth rate shows that the observed OCH waves can be excited by energetic O+s with the partial‐shell velocity distribution, and the maximum growth rate occurs at the third harmonic, coinciding with the frequency associated with the maximum peak of the wave electric field power spectral density measured. In addition, it is found that cool heavy ions have a damping effect on the OCH waves near the corresponding heavy ion cyclotron frequency.

Preferred Chemical Agent for Electrochemical Modification of Physical and Mechanical Parameters of Mudstone

To study the influence of electrochemically modified mediums on the physical and mechanical parameters of mudstone samples, focusing on electrolyte solutions and electrode materials, this paper combines theoretical analysis and experimental research. It analyzes the modification mechanism of mudstone through electrochemical techniques, clarifying that the main factors improving the strength of mudstone are electro-osmotic drainage consolidation and electrochemical reaction cementation. The mudstone was electrochemically modified using the controlled variable method. The mudstone sample’s hydraulic properties and shear strength were measured before and after modification. The study compared and analyzed the effectiveness of different modified materials. The results indicated that the liquid limit of the modified mudstone samples decreased by 7.874%, while the plastic limit increased by 9.499%. The type of ions introduced by the electrolyte solution influenced the cementation strength of the mudstone. AlCl3 solutions with a 10% mass fraction and CaCl2 solutions with a 25% mass fraction both effectively modify the reinforcement; however, the AlCl3 solution with a 10% mass fraction is the most effective for modifying mudstone samples. The electrochemical modification of mudstone samples with the three electrode materials (graphite, iron and aluminum) revealed that the samples modified with graphite electrodes had the highest shear strength, while those modified with aluminum electrodes had the lowest shear strength. The internal friction angle of graphite electrode-modified mudstone specimens was 26.7°, compared to the original value of 23.9°, and the cohesion was 34.4 kPa, compared to the original value of 12.3 kPa, nearly three times the original value. It is recommended to use graphite electrodes and a 10% mass fraction of AlCl3 for the electrochemical modification of this type of mudstone in engineering applications.

Prediction of normal tissue complication probability for rat spinal cord tolerance following ion irradiations

Objective.Currently, treatment planning in cancer hadrontherapy relies on dose-volume criteria and physical quantities constraints. However, incorporating biologically related models of tumor control probability and of normal tissue complication probability (NTCP) would help further minimizing adverse tissue reactions, and would allow achieving a more patient-specific strategy. The aim of this work was therefore the development of a mechanistic approach to predict NTCP for late tissue reactions following ion irradiation.Approach.A dataset on the tolerance of the rat spinal cord was considered, providing NTCP (for paresis of at least grade II) experimental data following irradiation by photons, protons, helium and carbon ions, under different fractionation schemes. The photon data were fit by a mechanistic NTCP model with four parameters, called Critical Element Model; this allowed fixing the two parameters that only depend on the tissue features. Afterwards, the two parameters depending on radiation quality were predicted by applying the BIophysical ANalysis of Cell death and chromosome Aberrations biophysical model, for each ion type and dose-averaged linear energy transfer value.Main results.The predicted NTCP curves for ion irradiation were tested against the ion experimental data, by Chi-Square andp-value calculations. The model passed a significance test at 1% for all the datasets, and 5% for 13 out of 16 datasets, thus showing a good predictive power. The Relative biological effectiveness (RBE) was also calculated and compared with the data for the endpoint of NTCP equal to 50%, and a considerable discrepancy with the commonly calculated RBE for cell survival was shown.Significance.This study highlights the importance of considering the endpoint of interest when computing the RBE, through the application of a NTCP model, and it represents a first step towards the development of an approach to improve treatment plan optimization in therapy. To this aim, the approach needs to be extended to other endpoints and to be applied to patients' data.