Superlong cycle-life sodium-ion batteries supported by electrode/active material interaction and heteroatom doping: Mechanism and application.

To achieve both the capacity and stability of metal sulfides simultaneously remains a significant challenge. In this study, we have synthesized the manganese-doped copper sulfide three-dimensional (3D) hollow flower-like sphere (M/CuS-NSC), encapsulated in a nitrogen and sulfur co-doped carbon. The hollow lamellae structure allows the rational self-aggregation process of numerous active surface area enlarged nanosheets, thereby enhancing electrochemical activity. The subsurface framework characterized by CSC bonds enhances the pseudo-capacitive properties. Furthermore, the transformation of sulfur and the isomerization of carbon contribute to the enhancement of sodium ion storage. The incorporation of Mn into CuS lattice increases the interplanar distance, providing additional space for the accommodation of sodium ions. Mn doping facilitates the localization of electrons near the Fermi level, thereby improving conductivity. Additionally, Cu foils coated with M/CuS-NSC-2 engage with the electrolyte and sulfur, initiating the reaction sequence through the formation of Cu9S8. Consequently, M/CuS-NSC-2 exhibits highly reversible capacities of 676.24 mAh g-1 after 100 cycles at 0.1 A g-1 and 511.52 mAh g-1 after 10000 cycles at 10 A g-1, with an average attenuation ratio of only 0.009 %. In this study, we propose an effective strategy that combines structural design with heteroatom doping, providing a novel approach to enhance the electrochemical performance of monometallic sulfide.

Effect of high sodium ion level on the interaction of AmB with a cholesterol-rich phospholipid monolayer.

Invasive fungal infections are a primary reason for high mortality in immunocompromised people, especially in critically ill patients, such as intensive care unit (ICU) patients, advanced cancer patients, or severe burn patients. Hypernatremia also can increase mortality in severely ill patients. Amphotericin B (AmB) is the gold standard for treating infections, but in severely ill patients, AmB can cause hematotoxicity when administered intravenously due to its interaction with cholesterol on red blood cell membranes. This results in limited doses of AmB and affects the treatment of infections. The proportion of cholesterol molecules in membrane lipids in red blood cells is as high as 50 mol%, and the sodium ions can influence the interaction between AmB and lipids on the membrane. Therefore, in the complex clinical situation of a severely ill patient with a fungal infection and hypernatremia, the interaction between amphotericin B and the red blood cell membranes is worth studying in depth. In this work, the interaction between AmB and the dipalmitoyl phosphatidylcholine (DPPC)/cholesterol mixed monolayer in the presence of high sodium ion levels was studied when the proportion of cholesterol was 50%. The results show that the effect of AmB on reducing the monolayer's area at a high level of sodium ions is slightly stronger at 30 mN/m. The effect of AmB on reducing the elastic modulus of the DPPC/Chol monolayer is significantly weakened by a high sodium ion level, compared with the level of sodium ions at normal physiological concentration. The higher the sodium ion concentration, the weaker the intermolecular force of the DPPC/Chol/AmB mixed monolayers. The scanning electron microscope (SEM) and atomic force microscopy (AFM) observations suggest that at a high sodium ion level, the presence of AmB significantly reduces the surface roughness of the DPPC/Chol monolayer. AmB may bind to cholesterol molecules, and it isolates cholesterol from the monolayer, resulting in a reduced height of the cholesterol-rich monolayer and an increasingly dispersed monolayer region. The results are beneficial to understanding the mechanism of impact of a high sodium ion level on the relationship between AmB and red blood cell membranes rich in cholesterol and are valuable for understanding the hemolytic toxicity of AmB to red blood cells at a high sodium ion level.

Mechanistic insights into sodium ion-mediated ligand binding affinity and modulation of 5-HT2B GPCR activity: implications for drug discovery and development.

PURPOSE: The G-protein coupled receptor (GPCR) family, implicated in neurological disorders and drug targets, includes the sensitive serotonin receptor subtype, 5-HT2B. The influence of sodium ions on ligand binding at the receptor's allosteric region is being increasingly studied for its impact on receptor structure. METHODS: High-throughput virtual screening of three libraries, specifically the Asinex-GPCR library, which contains 8,532 compounds and FDA-approved (2466 compounds) and investigational compounds (2731)) against the modeled receptor [4IB4-5HT2BRM] using the standard agonist/antagonist (Ergotamine/Methysergide), as previously selected from our studies based on ADMET profiling, and further on basis of binding free energy a single compound - dihydroergotamine is chosen. RESULTS: This compound displayed strong interactions with the conserved active site. Ions influence ligand binding, with stronger interactions (3-H-bonds and 1-π-bond around 3.35 Å) observed when an agonist and ions are present. Ions entry is guided by conserved motifs in helices III, IV, and VII, which regulate the receptor. Dihydroergotamine, the selected drug, showed binding variance based on ions presence/absence, affecting amino acid residues in these motifs. DCCM and PCA confirmed the stabilization of ligands, with a greater correlation (∼46.6%-PC1) observed with ions. Dihydroergotamine-modified interaction sites within the receptor necessary for activation, serving as a potential 5HT2BRM agonist. RDF analysis showed the sodium ions density around the active site during dihydroergotamine binding. CONCLUSION: Our study provides insights into sodium ion mobility's role in controlling ligand binding affinity in 5HT2BR, offering therapeutic development insights.

Semi-Coherent Heterointerface Engineering via In Situ Phase Transition for Enhanced Sodium/Lithium-Ions Storage.

To improve ion transport kinetics and electronic conductivity between the different phases in sodium/lithium-ion battery (LIB/SIB) anodes, heterointerface engineering is considered as a promising strategy due to the strong built-in electric field. However, the lattice mismatch and defects in the interphase structure can lead to large grain boundary resistance, reducing the ion transport kinetics and electronic conductivity. Herein, monometallic selenide Fe3Se4-Fe7Se8 semi-coherent heterointerface embedded in 3D connected Nitrogen-doped carbon yolk-shell matrix (Fe3Se4-Fe7Se8@NC) is obtained via an in situ phase transition process. Such semi-coherent heterointerface between Fe3Se4 and Fe7Se8 shows the matched interfacial lattice and strong built-in electric field, resulting in the low interface impedance and fast reaction kinetics. Moreover, the yolk-shell structure is designed to confine all monometallic selenide Fe3Se4-Fe7Se8 semi-coherent heterointerface nanoparticles, improving the structural stability and inhibiting the volume expansion effect. In particular, the 3D carbon bridge between multi-yolks shell structure improves the electronic conductivity and shortens the ion transport path. Therefore, the efficient reversible pseudocapacitance and electrochemical conversion reaction are enabled by the Fe3Se4-Fe7Se8@NC, leading to the high specific capacity of 439 mAh g-1 for SIB and 1010 mAh g-1 for LIB. This work provides a new strategy for constructing heterointerface of the anode for secondary batteries.

Pre-Oxidation Strategy Transforming Waste Foam to Hard Carbon Anodes for Boosting Sodium Storage Performance.

Large reserves, high capacity, and low cost are the core competitiveness of disordered carbon materials as excellent anode materials for sodium-ion batteries (SIBs). And the existence and improper treatment of a large number of organic solid wastes will aggravate the burden on the environment, therefore, it is significant to transform wastes into carbon-based materials for sustainable energy utilization. Herein, a kind of hard carbon materials are reported with waste biomass-foam as the precursor, which can improve the sodium storage performance through pre-oxidation strategy. The introduction of oxygen-containing groups can promote structural cross-linking, and inhibit the melting and rearrangement of carbon structure during high-temperature carbonization that produces a disordered structure with a suitable degree of graphitization. Moreover, the micropore structure are also regulated during the high-temperature carbonization process, which is conducive to the storage of sodium ions in the low-voltage plateau region. The optimized sample as an electrode material exhibits excellent reversible specific capacity (308.0 mAh g-1) and initial Coulombic efficiency (ICE, 90.1%). In addition, a full cell with the waste foam-derived hard carbon anode and a Na3V2(PO4)3 cathode is constructed with high ICE and energy density. This work provides an effective strategy to conversion the waste to high-value hard carbon anode for sodium-ion batteries.

Ensifer sp. GMS14 enhances soybean salt tolerance for potential application in saline soil reclamation.

Rhizosphere microbiomes play an important role in enhancing plant salt tolerance and are also commonly employed as bio-inoculants in soil remediation processes. Cultivated soybean (Glycine max) is one of the major oilseed crops with moderate salt tolerance. However, the response of rhizosphere microbes me to salt stress in soybean, as well as their potential application in saline soil reclamation, has been rarely reported. In this study, we first investigated the microbial communities of salt-treated and non-salt-treated soybean by 16S rRNA gene amplicon sequencing. Then, the potential mechanism of rhizosphere microbes in enhancing the salt tolerance of soybean was explored based on physiological analyses and transcriptomic sequencing. Our results suggested that Ensifer and Novosphingobium were biomarkers in salt-stressed soybean. One corresponding strain, Ensifer sp. GMS14, showed remarkable growth promoting characteristics. Pot experiments showed that GMS14 significantly improved the growth performance of soybean in saline soils. Strain GMS14 alleviated sodium ions (Na+) toxicity by maintaining low a Na+/K+ ratio and promoted nitrogen (N) and phosphorus (P) uptake by soybean in nutrient-deficient saline soils. Transcriptome analyses indicated that GMS14 improved plant salt tolerance mainly by ameliorating salt stress-mediated oxidative stress. Interestingly, GMS14 was evidenced to specifically suppress hydrogen peroxide (H2O2) production to maintain reactive oxygen species (ROS) homeostasis in plants under salt stress. Field experiments with GMS14 applications showed its great potential in saline soil reclamation, as evidenced by the increased biomass and nodulation capacity of GMS14-inoculated soybean. Overall, our findings provided valuable insights into the mechanisms underlying plant-microbes interactions, and highlighted the importance of microorganisms recruited by salt-stressed plant in the saline soil reclamation.

Recent technical developments and clinical research applications of sodium (23Na) MRI.

Sodium is an essential ion that plays a central role in many physiological processes including the transmembrane electrochemical gradient and the maintenance of the body's homeostasis. Due to the crucial role of sodium in the human body, the sodium nucleus is a promising candidate for non-invasively assessing (patho-)physiological changes. Almost 10 years ago, Madelin et al. provided a comprehensive review of methods and applications of sodium (23Na) MRI (Madelin et al., 2014) [1]. More recent review articles have focused mainly on specific applications of 23Na MRI. For example, several articles covered 23Na MRI applications for diseases such as osteoarthritis (Zbyn et al., 2016, Zaric et al., 2020) [2,3], multiple sclerosis (Petracca et al., 2016, Huhn et al., 2019) [4,5] and brain tumors (Schepkin, 2016) [6], or for imaging certain organs such as the kidneys (Zollner et al., 2016) [7], the brain (Shah et al., 2016, Thulborn et al., 2018) [8,9], and the heart (Bottomley, 2016) [10]. Other articles have reviewed technical developments such as radiofrequency (RF) coils for 23Na MRI (Wiggins et al., 2016, Bangerter et al., 2016) [11,12], pulse sequences (Konstandin et al., 2014) [13], image reconstruction methods (Chen et al., 2021) [14], and interleaved/simultaneous imaging techniques (Lopez Kolkovsky et al., 2022) [15]. In addition, 23Na MRI topics have been covered in review articles with broader topics such as multinuclear MRI or ultra-high-field MRI (Niesporek et al., 2019, Hu et al., 2019, Ladd et al., 2018) [16-18]. During the past decade, various research groups have continued working on technical improvements to sodium MRI and have investigated its potential to serve as a diagnostic and prognostic tool. Clinical research applications of 23Na MRI have covered a broad spectrum of diseases, mainly focusing on the brain, cartilage, and skeletal muscle (see Fig. 1). In this article, we aim to provide a comprehensive summary of methodological and hardware developments, as well as a review of various clinical research applications of sodium (23Na) MRI in the last decade (i.e., published from the beginning of 2013 to the end of 2022).

A Novel Composite Hydrogel Material for Sodium Removal and Potassium Provision.

Sodium ions are commonly found in natural water sources, and their high concentrations can potentially lead to adverse effects on both the water sources and soil quality. In this study, we successfully synthesized potassium polyacrylate (KMAA) hydrogel through free radical polymerization and evaluated its capability to remove sodium ions from and supply potassium ions to aqueous solutions. To assess its performance, inductively coupled plasma emission spectroscopy (ICP) was employed to analyze the sodium ion removal capacity and potassium ion exchange capability of the KMAA hydrogel at various initial sodium ion concentrations and pH values. The results demonstrated that the KMAA hydrogel exhibited remarkable efficiency in removing sodium ions and providing potassium ions. At pH 7, the maximum adsorption capacity for sodium ions was measured at 70.7 mg·g-1. The Langmuir model, with a correlation coefficient of 0.98, was found to be more suitable for describing the adsorption process of sodium ions. Moreover, at pH 4, the maximum exchange capacity for potassium ions reached 243.7 mg·g-1. The Freundlich model, with a correlation coefficient of 0.99, was deemed more appropriate for characterizing the ion exchange behavior of potassium ions. In conclusion, the successfully synthesized KMAA hydrogel demonstrates superior performance in removing sodium ions and supplying potassium ions, providing valuable insights for addressing high sodium ion concentrations in water sources and facilitating potassium fertilizer supply.

Enhancing interface stability and ionic conductivity in the designed Na3SbP0.4xS4-xOx sulfide solid electrolyte through bridging oxygen.

The all-solid-state sodium battery has emerged as a promising candidate for energy storage. However, the limited electrochemical stability of the solid electrolyte, particularly in the presence of Na metal at the anode, along with low ionic conductivity, hinders its widespread application. In this work, the design of P and O elements in Na3SbS4 solid electrolyte was investigated through a series of structural tests and characterizations. The electrochemical stability was remarkably improved in the Na/Na3SbP0.16S3.6O0.4/Na battery, exhibiting a stability of 260 h under a current of 0.1 mA cm-2. Additionally, the room temperature conductivity of Na3SbP0.16S3.6O0.4 was enhanced to 3.82 mS cm-1, maintaining a value comparable to commercial standards. The proposed design strategy provides an approach for developing sodium ion solid-state batteries with high energy density and long lifespan. The stability of the solid electrolyte interface at the Na | solid electrolyte interface proves critical for the successful assembly of all-solid-state sodium ion batteries.

An Atomic Level Investigation of Sodium Ions Regulating Agonist and Antagonist Binding in the Active Site of a Novel Target 5HT2BR Against Drug-Resistant Epilepsy.

The study investigates the movement of sodium ions inside the ligand-binding pocket of the class-A GPCR serotonin receptor (5HT2BR), a primary target for modern drugs. The available PDBs are mutant chimeras, so a 3D structure is modeled and validated by structural similarity (84.05%), Ramachandran favorable residues (93.01%), and clash score. Using MD simulations (500 ns), the ion active site is tracked in the presence and absence of ions and ligands. The ions enter the active site along helices III, VI, and VII, and the primary residue (ASP3.32) interacts with ions via H-bond (stronger- ~2.4 Å). The radial distribution function around ASP3.32 rises promptly at intermediate distances (2 Å < r < 4 Å), suggesting a higher probability of finding sodium ions at these distances. The ions stabilize the receptor at a better RMSD and promote stronger interactions (3-H-bonds, 1-π-bond~3.35 Å) with the agonist, and not the antagonist (no H-bond). Simulating unrestrained ligands further confirms this pattern, suggesting that ions might promote agonist binding but not be a prerequisite for antagonist action. The study highlights the mechanistic evaluation of sodium ions mobility in 5HT2BR modulation and ligand binding, showing potential in drug development.

Serum sodium ions and chloride ions associated with taxane-induced peripheral neuropathy in Chinese patients with early-stage breast cancer: A nation-wide multicenter study.

BACKGROUND: Taxane-induced peripheral neuropathy (TIPN) is a debilitating adverse effect of cancer treatments with taxanes which may require a reduction or discontinuation chemotherapy and affect clinical and survival outcomes. A number of factors have contributed to the increasing prevalence of TIPN. Nonetheless, limited knowledge exists of potential prechemotherapy blood-based biochemical factors associated with TIPN development. METHODS: We recruited breast cancer patients at seven cancer institutions in China. Participants aged 18 years or older with stage I to III breast cancer who scheduled to undergo primary neoadjuvant and adjuvant chemotherapy with taxanes were eligible. Eligible patients underwent patient-reported neuropathy assessments using the EORTC-CIPN20 questionnaire. Patients completed the questionnaire before commencing treatment and after every cycle. For every patient, we selected the highest TIPN toxicity score for analysis since the first cycle. The posttreatment TIPN severity was compared with blood-based biochemical factors within 30 days before commencing treatment. Independent samples t tests, Mann-Whitney U tests and linear regression were used to identify blood-based and clinical associations with TIPN development. RESULTS: The study included 873 breast cancer participants who received paclitaxel, docetaxel or nanoparticle albumin-bound (nab)-paclitaxel. In the whole cohort, factors associated with higher TIPN toxicity scores were higher cumulative chemotherapy dose (ß = 0.005; 95% CI, 0.004 to 0.006; P < .001), lower sodium ions (ß = -0.24; 95% CI, -0.39 to -0.09; P = .002) and higher chloride ions (ß = 0.30; 95% CI, 0.16 to 0.44; P < .001). CONCLUSIONS: The findings suggest that breast cancer patients with a higher cumulative chemotherapy dose, lower pretreatment sodium ions, and higher pretreatment chloride ions receiving taxanes should receive closer monitoring to mitigate the development of short-term and long-term TIPN.

Effect of water diuresis with hydrogen saturation on the course of acute kidney damage during the separation of oxidation and phosphorylation.

Molecular hydrogen has the ability to penetrate cells, easily reach mitochondria, overcome body barriers, penetrate areas of ischemia, edema and inflammation, improve energy supply by supplying additional electrons and have antioxidant and anti-inflammatory effects by neutralizing highly reactive hydroxyl radical and peroxynitrite. In this experiment, we included 60 nonlinear male rats weighing 0.16-0.18 kg and investigated the effect of a negative redox potential solution -297.3±5.27 mV with a molecular hydrogen saturation of 1.2 ppm on the functional-biochemical processes of the kidneys in tissue hypoxia in moderately resistant rats during the separation of oxidation and phosphorylation with the introduction of 2,4-dinitrophenol at a dose of 3 mg/kg. All studies were performed on moderately stable rats. Experimental, functional, biochemical, enzyme-linked immunosorbent, physicochemical, histoenzymochemical, and statistical research methods were used. Under conditions of renal hypoxia in the separation of oxidation and phosphorylation, the use of a solution of negative redox reabsorption of sodium ions in the distal nephron reduces the manifestations of tubular proteinuria, increases the activity of succinate dehydrogenase in the proximal nephron and reduces the redox potential of urine to negative values. Negative redox potential solution with molecular hydrogen saturation has a protective effect on the kidneys and reduces elevated levels of proinflammatory cytokines of tumor necrosis factor-α, interleukin-1-ß, and interleukin-6 in blood plasma, and causes oxidative modification of proteins in the renal cortex for their hypoxia in the separation of oxidation and phosphorylation.

PfATP4 inhibitors in the Medicines for Malaria Venture Malaria Box and Pathogen Box block the schizont-to-ring transition by inhibiting egress rather than invasion.

The cation efflux pump Plasmodium falciparum ATPase 4 (PfATP4) maintains Na+ homeostasis in malaria parasites and has been implicated in the mechanism of action of many structurally diverse antimalarial agents, including >7% of the antimalarial compounds in the Medicines for Malaria Venture's 'Malaria Box' and 'Pathogen Box'. Recent screens of the 'Malaria Box' and 'Pathogen Box' revealed that many PfATP4 inhibitors prevent parasites from exiting their host red blood cell (egress) or entering new host cells (invasion), suggesting that these compounds may have additional molecular targets involved in egress or invasion. Here, we demonstrate that five PfATP4 inhibitors reduce egress but not invasion. These compounds appear to inhibit egress by blocking the activation of protein kinase G, an enzyme that, once stimulated, rapidly activates parasite egress. We establish a direct link between egress and PfATP4 function by showing that the inhibition of egress is attenuated in a Na+-depleted environment and in parasites with a mutation in pfatp4. Finally, we show that PfATP4 inhibitors induce host cell lysis when administered prior to the completion of parasite replication. Since host cell lysis mimics egress but is not followed by invasion, this phenomenon likely explains why several PfATP4 inhibitors were previously classified as invasion inhibitors. Collectively, our results confirm that PfATP4-mediated Na+ efflux is critical to the regulation of parasite egress.

Effects of irrigation and nitrogen fertilization on mitigating salt-induced Na+ toxicity and sustaining sea rice growth.

This study investigated the effects of irrigation and nitrogen (N) fertilization on mitigating salt-induced Na+ toxicity and sustaining sea rice growth for perfecting irrigation and fertilization of sea rice. Three irrigation methods (submerged irrigation, intermittent irrigation, and controlled irrigation), three kinds of N fertilizers (urea, controlled release urea, and mixed N fertilizer), and control treatment without NaCl were set up in a pot experiment of sea rice with NaCl stress. The electrical conductivity in root layer soil of treatment with mixed N fertilizer and intermittent irrigation decreased slowly with the growth of rice and was significantly smaller than that of other treatments with NaCl. The Na+ content in sea rice of intermittent irrigation was the least, and that of submerged irrigation was significantly smaller than that of controlled irrigation, but the K+ and Ca2+ contents of three irrigation treatments were opposite to the Na+ content. The Na+ content of treatment with mixed N fertilizer and intermittent irrigation was the lowest, while the K+, Ca2+, and Mg2+ contents of mixed N fertilizer and intermittent irrigation were the highest in treatments with NaCl. The cell membrane permeability and malondialdehyde contents of rice leaves of mixed N fertilizer and intermittent irrigation were significantly smaller than those of other treatments with NaCl. The rice yield of mixed N fertilizer was significantly greater than that of urea and controlled release urea, and that of mixed N fertilizer and intermittent irrigation was increased by 104, 108, 277, 300, and 334% compared with mixed N fertilizer and submerged irrigation, urea and intermittent irrigation, urea and submerged irrigation, controlled release urea and intermittent irrigation, and controlled release urea and submerged irrigation, respectively. Therefore, the treatment of mixed N fertilizer and intermittent irrigation is worth recommending for being used for planting sea rice on coastal saline-sodic soil.

Detection of intracellular sodium ions based on phenotype-specific activation of NaA43 DNAzyme.

The intracellular sodium ion is one of the crucial elements for regulating physiological functions such as action potential and muscle contractions. However, detecting sodium ions in live cells is challenging because false signals may arise from the abundant sodium ions in the extracellular environment when introducing the detection agents. To minimize it, we report a DNAzyme-based detection of sodium ions in live cells via activation by endogenous mRNA. The substrate strand of DNAzyme first hybridizes to a blocking strand that prevents undesired cleavage of DNAzyme when delivered. Once entering cells, an endogenous mRNA biomarker binds to the toehold region of the blocking strand and displaces it, allowing the proper formation of the DNAzyme, which specifically catalyzes the cleavage of the substrate strand in the presence of intracellular Na+ and produces fluorescence signals. Using differentiating skeletal muscle cells as the model system, we demonstrated the successful delivery and phenotype-specific detection of intracellular sodium ions only in differentiated myotubes with highly-expressed myosin heavy chain mRNA. Moreover, using a drug cocktail to increase the permeability of the cell membrane, elevated levels of intracellular sodium ion was observed. This platform offers a broad and promising strategy for detecting intracellular metal ions, suggesting a great potential for understanding its role in cell/tissue physiology.

Graphene-Based Ion-Selective Field-Effect Transistor for Sodium Sensing.

Field-effect transistors have attracted significant attention in chemical sensing and clinical diagnosis, due to their high sensitivity and label-free operation. Through a scalable photolithographic process in this study, we fabricated graphene-based ion-sensitive field-effect transistor (ISFET) arrays that can continuously monitor sodium ions in real-time. As the sodium ion concentration increased, the current-gate voltage characteristic curves shifted towards the negative direction, showing that sodium ions were captured and could be detected over a wide concentration range, from 10-8 to 10-1 M, with a sensitivity of 152.4 mV/dec. Time-dependent measurements and interfering experiments were conducted to validate the real-time measurements and the highly specific detection capability of our sensor. Our graphene ISFETs (G-ISFET) not only showed a fast response, but also exhibited remarkable selectivity against interference ions, including Ca2+, K+, Mg2+ and NH4+. The scalability, high sensitivity and selectivity synergistically make our G-ISFET a promising platform for sodium sensing in health monitoring.

In-Situ growing tungsten Sulfide/Carbon nanosheets on sodium titanate nanorods to stabilize Surface-Structure for enhanced Sodium-ion storage.

Sodium-ions hybrid capacitors (SIHCs) have been recognized as one of the most potential energy storage devices, which can deliver high power and energy densities simultaneously. However, the sluggish kinetics of electrode materials severely restricts the performance of SIHCs. Herein, N, P-codoped carbon and WS2 nanosheets coating on sodium titanate nanorods (NTO@WS2/N, PC) were first designed by in-situ growing process and sulfuration treatment for boosting sodium-ion storage. Specifically, NTO@WS2/N, PC electrodes displayed a satisfactory specific capacity of 274.7 mAh g-1 at 3.0 A g-1 after 1200 cycles. Furthermore, as-assembled SIHCs delivered high-energy density of 112.1 Wh kg-1 and high-power density of 4334.4 W kg-1. Besides, long-term cycling test revealed that a remarkable capacity retention rate of 89.7% was obtained at 8.0 A g-1 after 2000 cycles. The excellent cycling stability and rate property could be ascribed to following aspects. On the one hand, N, P-codoped carbon could enhance the electrical conductivity and strengthen the structural integrality of the composites. On the other hand, ultrathin WS2 nanosheets and one-dimensional (1D) NTO nanorods structure were conducive to the rapid diffusion of Na+. This work provides a convenient technique to stabilize the structure of electrode materials, which can promote the practical application of SIHCs.

pH Homeostasis and Sodium Ion Pumping by Multiple Resistance and pH Antiporters in Pyrococcus furiosus.

Multiple Resistance and pH (Mrp) antiporters are seven-subunit complexes that couple transport of ions across the membrane in response to a proton motive force (PMF) and have various physiological roles, including sodium ion sensing and pH homeostasis. The hyperthermophilic archaeon Pyrococcus furiosus contains three copies of Mrp encoding genes in its genome. Two are found as integral components of two respiratory complexes, membrane bound hydrogenase (MBH) and the membrane bound sulfane sulfur reductase (MBS) that couple redox activity to sodium translocation, while the third copy is a stand-alone Mrp. Sequence alignments show that this Mrp does not contain an energy-input (PMF) module but contains all other predicted functional Mrp domains. The P. furiosus Mrp deletion strain exhibits no significant changes in optimal pH or sodium ion concentration for growth but is more sensitive to medium acidification during growth. Cell suspension hydrogen gas production assays using the deletion strain show that this Mrp uses sodium as the coupling ion. Mrp likely maintains cytoplasmic pH by exchanging protons inside the cell for extracellular sodium ions. Deletion of the MBH sodium-translocating module demonstrates that hydrogen gas production is uncoupled from ion pumping and provides insights into the evolution of this Mrp-containing respiratory complex.

Sodium-Sensitive Contact Lens for Diagnostics of Ocular Pathologies.

The ability to measure all the electrolyte concentrations in tears would be valuable in ophthalmology for research and diagnosis of dry eye disease (DED) and other ocular pathologies. However, tear samples are difficult to collect and analyze because the total volume is small and the chemical composition changes rapidly. Measurements of electrolytes in tears is challenging because typical clinical assays for proteins and other biomarkers cannot be used to detect ion concentrations tears. Here, we report the contact lens which is sensitive to sodium ion (Na+), one of the dominant electrolytes in tears. The Na ions in tears is diagnostic for DED. Three sodium-sensitive fluorophores (SG-C16, SG-LPE and SG-PL) were synthesized by derivatizing the sodium green with 1-hexadecyl amine, 1-oleoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine or poly-L-lysine, respectively. These probes were bound to modern silicone hydrogel (SiHG) contact lens, Biofinity from Cooper Vision. Doped lenses were tested for sodium ion dependent spectral properties of probes within the contact lens. The probes displayed changes in intensity and lifetime in response to Na+ concentration, were completely reversible, no significant probe wash-out from the lenses, were not affected by proteins in tears and were not removed after repeated washing. These results are the first step to our long-term goal, which is a lens sensitive to all the electrolytes in tears. We presented design, synthesis and implementation of three new sodium sensitive probes within a silicon hydrogel lens. Contact lenses to measure the other electrolytes in tears can be developed using the same approach by synthesis and testing of new ion-sensitive fluorophores.

Mathematical Modeling of Ion Quantum Tunneling Reveals Novel Properties of Voltage-Gated Channels and Quantum Aspects of Their Pathophysiology in Excitability-Related Disorders.

Voltage-gated channels are crucial in action potential initiation and propagation and there are many diseases and disorders related to them. Additionally, the classical mechanics are the main mechanics used to describe the function of the voltage-gated channels and their related abnormalities. However, the quantum mechanics should be considered to unravel new aspects in the voltage-gated channels and resolve the problems and challenges that classical mechanics cannot solve. In the present study, the aim is to mathematically show that quantum mechanics can exhibit a powerful tendency to unveil novel electrical features in voltage-gated channels and be used as a promising tool to solve the problems and challenges in the pathophysiology of excitability-related diseases. The model of quantum tunneling of ions through the intracellular hydrophobic gate is used to evaluate the influence of membrane potential and gating free energy on the tunneling probability, single channel conductance, and quantum membrane conductance. This evaluation is mainly based on graphing the mathematical relationships between these variables. The obtained mathematical graphs showed that ions can achieve significant quantum membrane conductance, which can affect the resting membrane potential and the excitability of cells. In the present work, quantum mechanics reveals original electrical properties associated with voltage-gated channels and introduces new insights and implications into the pathophysiology of excitability- related disorders. In addition, the present work sets a mathematical and theoretical framework that can be utilized to conduct experimental studies in order to explore the quantum aspects of voltage-gated channels and the quantum bioelectrical property of biological membranes.