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Comprehensive Summary: Regulating brain iron metabolism and reducing neuronal ferroptosis is proven to be a potential method for treating Alzheimer's disease (AD). However, gastric juice has a pH of 1.1—2.2 where a large number of interfering ions are dissociated from the food, which in turn causes traditional oral iron chelators to be saturated and inactivated. Herein, poly(4‐vinylbenzoic acid) polymer chains were introduced as guided by Fe3+ ion template into the porous network (TpPa‐1) via molecularly imprinted technology to obtain porous iron chelators, COOH@TpPa‐1. The COOH@TpPa‐1 maintains a multiple hydrogen bonding structure to block the channels in the stomach (pH ~1.1—2.2) with a strongly acidic environment, so just a small amount of active sites have been occupied. As COOH@TpPa‐1 enters the colon, the alkaline environment disrupts the original hydrogen‐bonded structure and forms anionic fragments, the bonding affinity for Fe3+ ions was ~4.0 times that in the stomach, and also gave a high selective coefficient 4.2 times higher than that of conventional iron chelators. These designable "on" and "off" states promote the effective enrichment of iron ions within the colon by the porous chelator and produce a favorable therapeutic effect on Alzheimer's symptoms caused by ferroptosis in mice. [ABSTRACT FROM AUTHOR]

Cathode materials are usually the key to determining battery capacity, suitable cathode materials are an important prerequisite to meet the needs of large‐scale energy storage systems in the future. Polyanionic compounds have significant advantages in metal ion storage, such as high operating voltage, excellent structural stability, safety, low cost, and environmental friendliness, and can be excellent cathode options for rechargeable metal‐ion batteries. Although some polyanionic compounds have been commercialized, there are still some shortcomings in electronic conductivity, reversible specific capacity, and rate performance, which obviously limits the development of polyanionic compound cathodes in large‐scale energy storage systems. Up to now, many strategies including structural design, ion doping, surface coating, and electrolyte optimization have been explored to improve the above defects. Based on the above contents, this paper briefly reviews the research progress and optimization strategies of typical polyanionic compound cathodes in the fields of lithium‐ion batteries (LIBs) and other promising metal ion batteries (sodium ion batteries (SIBs), potassium ion batteries (PIBs), magnesium ion batteries (MIBs), calcium ion batteries (CIBs), zinc ion batteries (ZIBs), aluminum ion batteries (AIBs), etc.), aiming to provide a valuable reference for accelerating the commercial application of polyanionic compound cathodes in rechargeable battery systems. [ABSTRACT FROM AUTHOR]

Desolvation processes, though common in self‐assembled biological structures, are rarely evidenced and utilized in the design of crystalline architectures. In this study, we introduce a novel approach using the [Mo8S8O8(OH)8(guest)]2− complex, formed by the self‐condensation of four [MoV2O2S2]2− fragments around a guest unit (MoVIO6H4 or oxalate), as a chaotropic scaffold for crystallizing hybrid organic‐inorganic systems with natural cyclodextrins. Our findings reveal that β‐cyclodextrin (β‐CD) facilitates the formation of host‐guest complexes, while α‐cyclodextrin (α‐CD) induces the formation of a Kagome‐type structure with significant voids. These new compounds were thoroughly characterized using X‐ray diffraction (both powder and single‐crystal), N2 adsorption, elemental and thermogravimetric analysis. Additionally, solution studies using 1H NMR titration and small‐angle X‐ray scattering (SAXS) demonstrated pre‐association of the building units in solution. These results enhance our understanding of the design principles for supramolecular structures composed of inorganic polyanions and cyclodextrins. [ABSTRACT FROM AUTHOR]

The tribe‐material is the key factor affecting the performance of triboelectric nanogenerators (TENGs). Inorganic materials have higher heat resistance and stability than widely used organic materials. However, the weaker tribe‐property limits the application of TENGs. Modulating surface roughness by changing particle shape and size is a simple way to increase performance for TENGs. Polyoxometalates (POMs) have unrivalled structural diversity and can self‐assemble to form different nanostructures. In this study, we propose [{(NH4)42[Mo72VIMo60VO372(CH3COO)30 (H2O)72] ⋅ ca.300H2O ⋅ ca.CH3COONH4)}‐Mo132] and [{Na8K14(VO)2[{(MoVI) (Mo5VIO21)(H2O)3]}10{(MoVI)Mo5VIO21(H2O)3 (SO4)}2{VIVO(H2O)20} {VIVO}10({KSO4}5)2] ⋅ 150H2O)}‐Mo72V30] with blackberry structure which are cured and prepared into film by spin‐coating technique, are used as positive tribe‐materials for the first time in the field of TENGs. Keplerate‐type POMs can form blackberry structures with higher dispersibility and flexibility, which can be used to control surface roughness by regulating the size of particles. The discovery proves that the particle size influences the surface roughness, which adjusts the output of TENGs. According to our findings, Mo132‐h‐TENG generates an output voltage of 29.3 V, an output charge of 8 Nc, which is 2–3 folds higher than Mo132‐TENG, and a maximum power density of 6.25 mW ⋅ m−2 at 300 MΩ. Our research provides that altering the dimensional size can be an available way to raise the output of TENGs. [ABSTRACT FROM AUTHOR]

Biocidal coatings are of great interest to the healthcare system. In this work, the biocidal activity of coatings based on a complex biocide containing polymer and inorganic active antibacterial components was studied. Silver oxide was distributed in a matrix of a positively charged interpolyelectrolyte complex (IPEC) of polydiallyldimethylammonium chloride (PDADMAC) and sodium polystyrene sulfonate (PSS) using ultrasonic dispersion, forming nanoparticles with an average size of 5–6 nm. The formed nanoparticles in the matrix are not subject to agglomeration and changes in morphology during storage. It was found that the inclusion of silver oxide in a positively charged IPEC allows a more than 4-fold increase in the effectiveness of the complex biocide against E. coli K12 in comparison with the biocidal effect of PDADMAC and IPEC. Polycation, IPEC, and the IPEC/Ag2O ternary complex form coatings on the glass surface due to electrostatic adsorption. Adhesive and cohesive forces in the resulting coatings were studied with micron-scale coatings using dynamometry. It was found that the stability of the coating is determined primarily by adhesive interactions. At the macro level, it is not possible to reliably identify the role of IPEC formation in adhesion. On the other hand, use of the optical tweezers method makes it possible to analyze macromolecules at the submicron scale and to evaluate the multiple increase in adhesive forces when forming a coating from IPEC compared to coatings from PDADMAC. Thus, the application of ternary IPEC/Ag2O complexes makes it possible to obtain coatings with increased antibacterial action and improved adhesive characteristics. [ABSTRACT FROM AUTHOR]

The synthesis of poly(styrene sulfonate) with hydrolysable ester groups in the main chain is reported. The material is obtained by free radical copolymerization of either styrene sulfonate sodium salt (SSNa) or styrene sulfonate alkyl esters (SSA) with the cyclic ketene acetal 2‐methylen‐1,3,6‐trioxocane (MTC). As for other systems made from cyclic ketene acetals, the reactions are difficult to control and give copolymers with high polydispersity index. MTC homopolymer is obtained as a side product in both cases. Thermal cleavage of the alkyl protective groups of the poly(styrene sulfonate alkyl esters) to obtain the target polystyrene sulfonate anions remains incomplete. Thus, direct synthesis of the polyanion from SSNa and MTC is the more efficient process, especially since the poly(SSNa‐co‐MTC) copolymer can be easily separated from MTC homopolymer. 1H‐NMR analytics indicates MTC repeat unit contents of 2–11%, depending on the initial SSNa to MTC ratio. The MTC ester groups of the copolymers are hydrolyzed in aqueous conditions, with and without enzyme, and a marked decrease in the molar mass is observed after hydrolysis. This confirms that these copolymers have the designed intended break points in the main chain, and could become a part of fully degradable electroactive polymer systems. [ABSTRACT FROM AUTHOR]

[Display omitted] Cationic poly(diallyldimethylammonium chloride) forms nonstoichiometric positively charged interpolyelectrolyte complexes (IPECs) with short- and long-chain anionic sodium polyacrylate. When added to anionic liposomes, the short-chain polyanion IPECs dissociate and the free polycation binds to the liposomes, whereas the long-chain polyanion IPECs bind to the liposomes as a whole. These results correlate with the antimicrobial activity of IPECs, thereby highlighting the important role of polymer molecular weight in the cellular response to IPEC binding. [ABSTRACT FROM AUTHOR]

The aromatic biopolymer lignin, present in lignocellulosic material, can act as an antioxidant and has antimicrobial and UV blocking properties due to the presence of aromatic ring and phenolic hydroxyl groups with aliphatic hydroxyl, carboxyl, methoxy groups. It is produced in huge amounts as a by-product during the delignification process in the paper and pulp industries. Lignin-based polymer composites with advantageous properties can fulfill the growing demand for lightweight polymer composites. Incorporating lignin as reinforcement in polymer composite can make it more environmentally friendly. Among four technical lignin, kraft lignin and lignosulfonate have a unique molecular structure that includes sulfur and can be extracted from black liquor and spent liquor, respectively. Moreover, the negatively charged sulfite groups in lignosulfonate can have an electrostatic attraction to a wide range of positively charged polymers and materials, making it an ideal additive for the adsorbent material. The main intention of this review is to increase the knowledge on the use of cheap and widely available kraft lignin and lignosulfonate as reinforcement in polymer composites and to find the shortcomings to advance further research on the application of technical lignin. The article mainly focuses on advancements in kraft lignin and lignosulfonate polymer composites.

Selenium (Se0) nanoparticles are stabilized with water-soluble polymers containing ionogenic groups of the different signs, namely, poly(N,N,N-trimethylammonium)ethyl methacrylate iodide (polycation) and sodium polystyrenesulfonate (polyanion). A comprehensive comparative study of the resulting selenium-containing nanodispersions by the UV–visible spectroscopy, atomic force and transmission electron microscopy, and dynamic and electrophoretic light-scattering methods is conducted. The effect of the charge sign of the polymer stabilizer on the structural–morphological, dimensional, electrochemical, and spectral characteristics of selenium-containing nanodispersions is shown. [ABSTRACT FROM AUTHOR]

Prion diseases, also known as transmissible spongiform encephalopathies, are caused by the accumulation of abnormal isoforms of the prion protein (scrapie isoform of the prion protein, PrPSc) in the central nervous system. Many compounds with anti-prion activities have been found using in silico screening, in vitro models, persistently prion-infected cell models, and prion-infected rodent models. Some of these compounds include several types of polymers. Although the inhibition or removal of PrPSc production is the main target of therapy, the unique features of prions, namely protein aggregation and assembly accompanied by steric structural transformation, may require different strategies for the development of anti-prion drugs than those for conventional therapeutics targeting enzyme inhibition, agonist ligands, or modulation of signaling. In this paper, we first overview the history of the application of polymers to prion disease research. Next, we describe the characteristics of each type of polymer with anti-prion activity. Finally, we discuss the common features of these polymers. Although drug delivery of these polymers to the brain is a challenge, they are useful not only as leads for therapeutic drugs but also as tools to explore the structure of PrPSc and are indispensable for prion disease research. [ABSTRACT FROM AUTHOR]

The aromatic biopolymer lignin, present in lignocellulosic material, can act as an antioxidant and has antimicrobial and UV blocking properties due to the presence of aromatic ring and phenolic hydroxyl groups with aliphatic hydroxyl, carboxyl, methoxy groups. It is produced in huge amounts as a by-product during the delignification process in the paper and pulp industries. Lignin-based polymer composites with advantageous properties can fulfill the growing demand for lightweight polymer composites. Incorporating lignin as reinforcement in polymer composite can make it more environmentally friendly. Among four technical lignin, kraft lignin and lignosulfonate have a unique molecular structure that includes sulfur and can be extracted from black liquor and spent liquor, respectively. Moreover, the negatively charged sulfite groups in lignosulfonate can have an electrostatic attraction to a wide range of positively charged polymers and materials, making it an ideal additive for the adsorbent material. The main intention of this review is to increase the knowledge on the use of cheap and widely available kraft lignin and lignosulfonate as reinforcement in polymer composites and to find the shortcomings to advance further research on the application of technical lignin. The article mainly focuses on advancements in kraft lignin and lignosulfonate polymer composites. [ABSTRACT FROM AUTHOR]

The exploration of high-energy-density cathode materials is vital to the practical use of K-ion batteries. Layered K-metal oxides have too high a voltage slope due to their large K+–K+ interaction, resulting in low specific capacity and average voltage. In contrast, the 3D arrangement of K+, with polyanions separating them, reduces the strength of the effective K+-K+ repulsion, which in turn increases specific capacity and voltage. Here, stoichiometric KVPO4F for use as a high-energy-density K-ion cathode is developed. The KVPO4F cathode delivers a reversible capacity of ≈105 mAh g−1 with an average voltage of ≈4.3 V (vs K/K+), resulting in a gravimetric energy density of ≈450 Wh kg−1. During electrochemical cycling, the KxVPO4F cathode goes through various intermediate phases at x = 0.75, 0.625, and 0.5 upon K extraction and reinsertion, as determined by ex situ X-ray diffraction characterization and ab initio calculations. This work further explains the role of oxygen substitution in KVPO4+xF1−x: the oxygenation of KVPO4F leads to an anion-disordered structure which prevents the formation of K+/vacancy orderings without electrochemical plateaus and hence to a smoother voltage profile.

[Display omitted] Aqueous solutions of poly(diallyldimethylammonium chloride) and its electrostatic complexes with sodium polyacrylate were deposited onto glass surfaces. Upon successive washing cycles, they formed thin stable coatings that exhibited antimicrobial activity towards gram-positive and gram-negative bacteria. The obtained results are valuable for the development of antibacterial coatings. [ABSTRACT FROM AUTHOR]

A study is performed of the electrochemical and hydrodynamic properties of sulfite lignin (lignosulfonate) in mixed aqueous–organic (EtOH/Ac) media. It is established that in an aqueous medium, lignosulfonate macromolecules exhibit the properties of a polyelectrolyte with a charge partially compensated for. It is found that in mixed aqueous–organic media, a transition is observed between modes of the behavior of lignosulfonate, from polyelectrolyte–ionomeric to ionomeric, and thus the separation of phases of the lignosulfonate–water–organic liquid system. The hydrodynamic size, polydispersity index, and ζ-potential of lignosulfonate-containing associates are determined. Air-dried nanopowders are obtained from mixed aqueous–organic media. It is shown that by changing the concentration of polyelectrolyte (0.020–200 g/dm3), the nature (EtOH/Ac) and content (φEtOH/Ac = 0.60–73.0 vol %), and the way of introducing an organic liquid, it is possible to flexibly control self-assembly processes and obtain aqueous dispersions or air-dried nanopowders of LS with different sizes (40–500 nm) and morphologies (nanoparticles, vesicles). [ABSTRACT FROM AUTHOR]

The development of a polyanion cathode for sodium-ion batteries is expected to accelerate the application of sodium-ion batteries in large-scale energy storage systems. However, the poor electrode conductivity is still a great challenge. In this paper, the novel carbon composite polyanion compound Na 3.16 Fe 2.42 (P 2 O 7) 2 @C (NFP@C) is developed through high-energy ball milling followed by annealing. The porous NFP nanoparticles modified with dual-functional C-composited for amorphous carbon coating and carbon nanofibers interpenetrating deliver excellent capacity retention of 85.3% after 1000 cycles at 5 C, which is more outstanding than pure NFP. X-ray diffraction, in situ galvanostatic intermittent titration techniques, electrochemical impedance spectroscopy, and cyclic voltammetry were performed to investigate the stability and sodium diffusion of NFP@C. The results show that the systematic and comprehensive dual-functional conductive network modification enables NFP exhibit excellent electronic and ionic conductivities, thereby improving the rate capability and cycling stability. Furthermore, a soft package sodium-ion full battery assembled based on NFP@C reveals a high-capacity retention of 95.2% for 150 cycles at 0.5C. This carbon composite strategy is simple and efficient and could be easily and widely extended to other cathodes in grid-scale energy storage applications. [ABSTRACT FROM AUTHOR]

The development of a tavorite structured K- transition metal (T M )- fluorophosphate, having earth-abundant Fe as the only T M , crystallizing in the orthorhombic crystal system and facilitating stable-cum-reversible electrochemical K-extraction/insertion, has been reported here. Synthesized using low-cost precursors, KFePO 4 F has also been found to be air-stable. Detailed information pertaining to the bonding/structure, including lattice site occupancy, have been obtained via diffraction, Raman spectroscopy and FTIR, with XPS, Mössbauer and ESR revealing the oxidation states and nature of Fe in the as-synthesized condition and upon being subjected to electrochemical potassiation/depotassiation. The electrochemical K-insertion/extraction, supported by reversible Fe-redox, leads to a reversible K-storage capacity of ~102 mAh/g (within 1.5-4.0 V), along with a 1 st cycle Coulombic efficiency (CE) of ~93 % (with CE>99.9 % from 2 nd cycle onwards). Ex-situ X-ray diffraction, as well as operando synchrotron diffraction during galvanostatic cycling, indicates reversible changes in peak positions upon electrochemical K-extraction/insertion, with no evidence for structural change. When used as cathode material in K-ion 'full' cell (with hard carbon-based anode), a discharge capacity of ~68 mAh/g, along with capacity retention of ~70 % after 50 cycles, has been obtained; which confirms that this newly-developed earth-abundant Fe-based potassium fluorophosphate can be utilized for potential application in sustainable battery chemistries, like K-ion batteries., (© 2024 Wiley-VCH GmbH.)

The progress on electrode materials over the last few years has greatly facilitated sodium‐ion batteries (SIBs) toward practical applications. Cost‐effectiveness is the key character to realize practical applications of SIBs. The iron‐based phosphate materials (IPBMs) are composed of the resource abundant and low‐cost Na–Fe–P–O system and have demonstrated intriguing sodium‐storage properties to reach this goal. Starting from NaFePO4, through compositional and structural engineering, many IPBMs have been developed in recent years. This review offers a comprehensive overview about the development of IPBMs. Crystal structure, electrochemical performance, and reaction mechanism of three main categories (phosphates, pyrophosphates, mixed polyanions) of IPBMs and their represented materials are systematically introduced. Besides, the key challenges encountered by IPBMs, including the impurity phase issue, low‐quality carbon coating, limited energy density, and random morphology are proposed. Finally, perspectives on the future development of IPBMs from intrinsic properties regulation to full battery manufacturing are highlighted in aspects of electrochemical performance enhancements, mechanism investigation, surface and electrolytes, and commercialization. It is believed that this review is timely and is of great importance to promote applications of cost‐effective sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

NASICON-type Na 4 MnCr(PO 4) 3 (NMCP) has gained significant attention due to its prominent capacity and voltage platform. However, poor intrinsic electron conductivity severely obstructed its wider application. Here, the NMCP was decorated through structurally integrated with the high conductive carbon nanotubes (CNTs) component via the sol-gel method. The CNTs additive was tightly implanted NMCP bulk, providing fast electron transfer rates, further reduced charge transfer resistance and ohmic resistance, and improving the electrochemical properties of NMCP during the reversible intercalation/deintercalation of Na+. Finally, the as-prepared rambutan-like NMCP/C@CNTs could release a high reversible capability of 118.7 mAh g−1 at 0.1C and exhibit long durability over 500 cycles at a high rate of 10C. The pseudocapacitance contributions were investigated, and the Na storage mechanism was also demonstrated through in-situ synchrotron X-ray diffraction. The assembled NMCP/C@CNTs//HC full cell could deliver a high energy density of 364.4 Wh kg−1. The encouraging electrochemical performance of the full cell will promote the development of sodium ion secondary batteries for large-scale applications in the future. [Display omitted] • Rambutan-like Na 4 MnCr(PO 4) 3 with heterogeneous carbon modified on the surface and inside of particles has been obtained. • The resultant NMCP/C@CNTs with satisfactory structure showed excellent rate capacities. • The NMCP/C@CNTs//HC full batteries delivered high energy density of 364.4 Wh kg−1. [ABSTRACT FROM AUTHOR]

Amyloid aggregation, including aggregation and propagation of prion protein, is a key factor in numerous human diseases, so-called amyloidosis, with a very poor ability for treatment or prevention. The present work describes the effect of sulfated or sulfonated polymers (sodium dextran sulfate, polystyrene sulfonate, polyanethole sulfonate, and polyvinyl sulfate) on different stages of amyloidogenic conversion and aggregation of the prion protein, which is associated with prionopathies in humans and animals. All tested polymers turned out to induce amyloid conversion of the ovine prion protein. As suggested from molecular dynamics simulations, this effect probably arises from destabilization of the native prion protein structure by the polymers. Short polymers enhanced its further aggregation, whereas addition of high-molecular poly(styrene sulfonate) inhibited amyloid fibrils formation. According to the seeding experiments, the protein–polymer complexes formed after incubation with poly(styrene sulfonate) exhibited significantly lower amyloidogenic capacity compared with the control fibrils of the free prion protein. The cytotoxicity of soluble oligomers was completely inhibited by treatment with poly(styrene sulfonate). To summarize, sulfonated polymers are a promising platform for the formulation of a new class of anti-prion and anti-amyloidosis therapeutics. [ABSTRACT FROM AUTHOR]

Abstract Background Evidence of crosstalk between the complement and coagulation cascades exists, and dysregulation of either pathway can lead to serious thromboinflammatory events. Both the intrinsic pathway of coagulation and the alternative pathway of complement interact with anionic surfaces, such as glycosaminoglycans. Hitherto, there is no evidence for a direct interaction of properdin (factor P [FP]), the only known positive regulator of complement, with coagulation factor XI (FXI) or activated FXI (FXIa). Objectives The aim was to investigate crosstalk between FP and the intrinsic pathway and the potential downstream consequences. Methods Chromogenic assays were established to characterize autoactivation of FXI in the presence of dextran sulfate (DXS), enzyme kinetics of FXIa, and the downstream effects of FP on intrinsic pathway activity. Substrate specificity changes were investigated using SDS‐PAGE and liquid chromatography–mass spectrometry (LC‐MS). Surface plasmon resonance (SPR) was used to determine direct binding between FP and FXIa. Results/Conclusions We identified a novel interaction of FP with FXIa resulting in functional consequences. FP reduces activity of autoactivated FXIa toward S‐2288. FXIa can cleave FP in the presence of DXS, demonstrated using SDS‐PAGE, and confirmed by LC‐MS. FXIa can cleave factor IX (FIX) and FP in the presence of DXS, determined by SDS‐PAGE. DXS alone modulates FXIa activity, and this effect is further modulated by FP. We demonstrate that FXI and FXIa bind to FP with high affinity. Furthermore, FX activation downstream of FXIa cleavage of FIX is modulated by FP. These findings suggest a novel intercommunication between complement and coagulation pathways.

Polymer coatings based on polycations represent a perspective class of protective antimicrobial coatings. Polydiallyldimethylammonium chloride (PDADMAC) and its water-soluble complexes with sodium polystyrenesulfonate (PSS) were studied by means of dynamic light-scattering, laser microelectrophoresis and turbidimetry. It was shown that addition of six mol.% of polyanion to polycation results in formation of interpolyelectrolyte complex (IPEC) that was stable towards phase separation in water-salt media with a concentration of salts (NaCl, CaCl2, Na2SO4, MgSO4) up to 0.5 M. Most of the polyelectrolyte coatings are made by layer-by-layer deposition. The utilization of water-soluble IPEC for the direct deposition on the surface was studied. The coatings from the PDADMAC and the PSS/PDADMAC complex were formed on the surfaces of hydrophilic glass and hydrophobic polyvinylchloride. It was found that formation IPEC allows one to increase the stability of the coating towards wash-off with water in comparison to individual PDADMAC coating on both types of substrates. The visualization of the coatings was performed by atomic force microscopy and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

The development of cathode materials has always been one of the most crucial areas of research in the field of sodium-ion batteries. Sulfate-based polyanionic materials, known for their high working voltage characteristics, have received widespread attention. In this work, a fluoro-sulfate sodium-ion battery cathode material, Na 3 Fe 2 (SO 4 ) 3 F modified with carbon nanotubes, was developed using a low-temperature solid-state annealing method. This Na 3 Fe 2 (SO 4 ) 3 F cathode exhibits an exceptionally high voltage of 3.77 V, excellent discharge capacity (102 mAh/g at 0.1C), and good rate capability. This material broadens the research directions for cathode materials and holds promise as a foundation for the further development of high-performance sodium-ion batteries.

[Display omitted] No other virus after the outbreak of the influenza pandemic of 1918 affected the world's population as hard as the coronavirus SARS-CoV-2. The identification of effective agents/materials to prevent or treat COVID-19 caused by SARS-CoV-2 is an urgent global need. This review aims to survey novel strategies based on inorganic polyphosphate (polyP), a biologically formed but also synthetically available polyanionic polymeric material, which has the potential of being a potent inhibitor of the SARS-CoV-2 virus-cell-docking machinery. This virus attaches to the host cell surface receptor ACE2 with its receptor binding domain (RBD), which is present at the tips of the viral envelope spike proteins. On the surface of the RBD an unusually conserved cationic groove is exposed, which is composed of basic amino acids (Arg, Lys, and His). This pattern of cationic amino acids, the cationic groove, matches spatially with the anionic polymeric material, with polyP, allowing an electrostatic interaction. In consequence, the interaction between the RBD and ACE2 is potently blocked. PolyP is a physiological inorganic polymer, synthesized by cells and especially enriched in the blood platelets, which releases metabolically useful energy through enzymatic degradation and coupled ADP/ATP formation. In addition, this material upregulates the steady-state-expression of the mucin genes in the epithelial cells. We propose that polyP, with its two antiviral properties (blocking the binding of the virus to the cells and reinforcing the defense barrier against infiltration of the virus) has the potential to be a novel protective/therapeutic anti-COVID-19 agent. [ABSTRACT FROM AUTHOR]

Metallic black platelet single crystals of a new ternary compound, Sr7N2Sn3, were obtained by heating Sr and Sn in a Na flux together with NaN3 as a nitrogen source at 1073 K, followed by slow cooling. Single-crystal X-ray analysis revealed that this compound crystallizes in an orthorhombic cell with the cell parameters a = 10.4082(2), b = 18.0737(4), and c = 7.43390(10) Å (space group Pmna, Z = 2), and has a layered (modular) antiperovskite-type structure which could be related to the inverse structure of Ca2Nb2O7 ((Ca2)[Ca2Nb4O14]). Four-membered zigzag [Sn4] chains are situated between slabs comprising four antiperovskite layers cut by the (110) plane of the ideal anitiperovskite structure, and Sr7N2Sn3 can be expressed as [Sn4][Sn2N4Sr14]. Although an electron-precise valence electron distribution according to the formula (Sr2+)14(N3−)4(Sn4−)2([Sn4]8−) is proposed for this ternary compound, yet, there are certain structural peculiarities which cannot be explained by this idealized picture. Therefore, first principles-based means were employed to account for the aforementioned structural features. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome–associated coronavirus 2 has caused a global public health crisis with high rates of infection and mortality. Treatment and prevention approaches include vaccine development, the design of small-molecule antiviral drugs, and macromolecular neutralizing antibodies. Polymers have been designed for effective virus inhibition and as antiviral drug delivery carriers. This review summarizes recent progress and provides a perspective on polymer-based approaches for the treatment and prevention of coronavirus infection. These polymer-based partners include polyanion/polycations, dendritic polymers, macromolecular prodrugs, and polymeric drug delivery systems that have the potential to significantly improve the efficacy of antiviral therapeutics.

Mg3−xGa1+xIr (x = 0.05) was synthesized by direct reaction of the elements in welded tantalum containers at 1200 °C and subsequent annealing at 500 °C for 30 days. Its crystal structure represents a new prototype and was determined by single-crystal technique as follows: space group P63/mcm, Pearson symbol hP90, Z = 18, a = 14.4970(3) Å, c = 8.8638(3) Å. The composition and atomic arrangement in Mg3GaIr do not follow the 8–N rule due to the lack of valence electrons. Based on chemical bonding analysis in positional space, it was shown that the title compound has a polycationic–polyanionic organization. In comparison with other known intermetallic substances with this kind of bonding pattern, both the polyanion and the polyanion are remarkably complex. Mg3−xGa1+xIr is an example of how the general organization of intermetallic substances (e.g., formation of polyanions and polycations) can be understood by extending the principles of 8–N compounds to electron-deficient materials with multi-atomic bonding.

Proper assembly and disassembly of both immature and mature HIV-1 hexameric lattices are critical for successful viral replication. These processes are facilitated by several host-cell factors, one of which is myo-inositol hexaphosphate (IP6). IP6 participates in the proper assembly of Gag into immature hexameric lattices and is incorporated into HIV-1 particles. Following maturation, IP6 is also likely to participate in stabilizing capsid protein-mediated mature hexameric lattices. Although a structural-functional analysis of the importance of IP6 in the HIV-1 life cycle has been reported, the effect of IP6 has not yet been quantified. Using two in vitro methods, we quantified the effect of IP6 on the assembly of immature-like HIV-1 particles, as well as its stabilizing effect during disassembly of mature-like particles connected with uncoating. We analyzed a broad range of molar ratios of protein hexamers to IP6 molecules during assembly and disassembly. The specificity of the IP6-facilitated effect on HIV-1 particle assembly and stability was verified by K290A, K359A, and R18A mutants. In addition to IP6, we also tested other polyanions as potential assembly cofactors or stabilizers of viral particles. [ABSTRACT FROM AUTHOR]

Reasonably simple, efficient, and possessing aspects of generality, the methodology for the synthesis of new, water-soluble, dendrimeric polyesters with great potential applications as antiviral drugs in their own right is described. The essential aspect of the presented approach is a quite unique, immediate access to the polyanionic material at each generation during divergent synthesis. Six target polyanionic dendrimers (generations 1, 2, and 3) have been synthesized. The key monomers applied in this project were 1,3,5-benzenetricarboxylic acid derivatives, which also worked as direct precursors of the charged dendrimer surface.

High-voltage generation (over 4 V versus Li+/Li) of polyanion-positive electrode materials is usually achieved by Ni3+/Ni2+, Co3+/Co2+, or V4+/V3+ redox couples, all of which, however, encounter cost and toxicity issues. In this short review, our recent efforts to utilize alternative abundant and less toxic Fe3+/Fe2+ and Cr4+/Cr3+ redox couples are summarized. Most successful examples are alluaudite Na2Fe2(SO4)3 (3.8 V versus sodium and hence 4.1 V versus lithium) and β1-Na3Al2(PO4)2F3-type Na3Cr2(PO4)2F3 (4.7 V versus sodium and hence 5.0 V versus lithium), where maximizing ΔG by edge-sharing Fe3+-Fe3+ Coulombic repulsion and the use of the 3d2/3d3 configuration of Cr4+/Cr3+ are essential for each case. Possible exploration of new high-voltage cathode materials is also discussed.

Abstract Molecular polyanion ammonium heptamolybdatetetrahydrate [(NH 4) 6 (Mo 7 O 24)]·4H 2 O (AHMT) was used to remove methylene blue (MB) dye from an aqueous solution through adsorption technique. Due to an electrostatic interaction of MB cation and AHMT anion adsorption take place. AHMT and MB adsorbed AHMT named as MB-AHMT was characterized by FT-IR, PXRD, SEM and SEM-EDX techniques. Specific surface area (22.175 m2 g−1) and pore volume (0.059 cm3 g−1) of AHMT was analyzed by BET analysis. The thermal stability and thermal degradation kinetics of adsorbent were assessed by the thermogravimetric curves recorded at different heating rates. The adsorption equilibrium and kinetic studies indicate that adsorption follows with pseudo first order (R > 0.9998) rather than pseudo second order. Temperature variation study indicates that adsorption was spontaneous, exothermic and entropy increased processes. Experimental data fitted well with Langmuir rather than Freundlich isotherm with maximum adsorption capacity of 877.19 mg g−1. Excess AHMT was recovered as salt of TBA-AHMT which was characterized by FT-IR spectroscopy. The investigations indicate that AHMT may be a prospective material for the removal of MB dye from polluted water. Graphical abstract Unlabelled Image Highlights • AHMT anion used as adsorbent for the removal of MB cationic dye and adsorbent recovered as Tetrabutylammonium salt. • Due to olation process maximum adsorption found in lower pH ie below PZC which is reverse to the discussion of literature. • TGA kinetics, chemical kinetics, Equilibrium & Thermodynamics parameters were calculated & fitted with model equations. • AHMT has potential to develop technology for treating MB polluted acidic industrial effluent / aqueous solution in low pH. • AHMT one among the rare example of cost effective adsorbent for the removal of MB dye [ABSTRACT FROM AUTHOR]

Abstract The interaction of proteins with polyanions and polycations is involved in many processes in living cell. These proteins undergo posttranslational modifications such as glycation, which change electrostatic interactions of the modified protein with other macromolecules and can significantly alter its behavior. In the present work, we investigated the influence of glycation by methylglyoxal of intrinsically disordered milk protein, β-casein, on its interaction with natural and model polyelectrolytes. Irrespective to glycation, β-casein interacted with polycation, forming large precipitating aggregates. Efficient interaction has been observed also for relatively hydrophobic polyanion, poly(styrene sulfonate). Interaction with hydrophilic sulfated polymer, heparin, as well as polyphosphate and polycarboxylate anions was much less pronounced. Significant weakening of the binding due to glycation of β-casein was observed for polycytidylate and poly(acrylate) but not for other polymers. The obtained results are important for the use of anionic polymers in milk food chemistry, especially for heat treatment in the presence of sugars. Graphical abstract Image 1 Highlights • β-casein interacts with polycation forming large aggregates. • Interaction with relatively hydrophobic polymers is the most efficient. • Glycation results in additional disordering of β-casein. • Glycation can influence on interaction with polyanions. • Temperature-induced micellization can be influenced by polyanions. [ABSTRACT FROM AUTHOR]

The assembly of a hexameric lattice of retroviral immature particles requires the involvement of cell factors such as proteins and small molecules. A small, negatively charged polyanionic molecule, myo-inositol hexaphosphate (IP6), was identified to stimulate the assembly of immature particles of HIV-1 and other lentiviruses. Interestingly, cryo-electron tomography analysis of the immature particles of two lentiviruses, HIV-1 and equine infectious anemia virus (EIAV), revealed that the IP6 binding site is similar. Based on this amino acid conservation of the IP6 interacting site, it is presumed that the assembly of immature particles of all lentiviruses is stimulated by IP6. Although this specific region for IP6 binding may be unique for lentiviruses, it is plausible that other retroviral species also recruit some small polyanion to facilitate the assembly of their immature particles. To study whether the assembly of retroviruses other than lentiviruses can be stimulated by polyanionic molecules, we measured the effect of various polyanions on the assembly of immature virus-like particles of Rous sarcoma virus (RSV), a member of alpharetroviruses, Mason-Pfizer monkey virus (M-PMV) representative of betaretroviruses, and murine leukemia virus (MLV), a member of gammaretroviruses. RSV, M-PMV and MLV immature virus-like particles were assembled in vitro from truncated Gag molecules and the effect of selected polyanions, myo-inostol hexaphosphate, myo-inositol, glucose-1,6-bisphosphate, myo-inositol hexasulphate, and mellitic acid, on the particles assembly was quantified. Our results suggest that the assembly of immature particles of RSV and MLV was indeed stimulated by the presence of myo-inostol hexaphosphate and myo-inositol, respectively. In contrast, no effect on the assembly of M-PMV as a betaretrovirus member was observed.

Na3V(PO4)2 was reported recently as a novel cathode material with high theoretical energy density for Sodium-ion batteries (SIBs). However, whether V3+/V4+/V5+ multielectron reactions can be realized during the charging process is still an open question. In this work, Na3V(PO4)2 is synthesized by using a solid-state method. Its atomic composition and crystal structure are verified by X-ray diffraction (XRD) and neutron diffraction (ND) joint refinement. The electrochemical performance of Na3V(PO4)2 is evaluated in two different voltage windows, namely 2.5−3.8 and 2.5−4.3 V. 51V solid-state NMR (ssNMR) results disclose the presence of V5+ in Na2−xV(PO4)2 when charging Na3V(PO4)2 to 4.3 V, confirming Na3V(PO4)2 is a potential high energy density cathode through realization of V3+/V4+/V5+ multielectron reactions.

Abstract: The exploration of high‐energy‐density cathode materials is vital to the practical use of K‐ion batteries. Layered K‐metal oxides have too high a voltage slope due to their large K+–K+ interaction, resulting in low specific capacity and average voltage. In contrast, the 3D arrangement of K+, with polyanions separating them, reduces the strength of the effective K+‐K+ repulsion, which in turn increases specific capacity and voltage. Here, stoichiometric KVPO4F for use as a high‐energy‐density K‐ion cathode is developed. The KVPO4F cathode delivers a reversible capacity of ≈105 mAh g−1 with an average voltage of ≈4.3 V (vs K/K+), resulting in a gravimetric energy density of ≈450 Wh kg−1. During electrochemical cycling, the KxVPO4F cathode goes through various intermediate phases at x = 0.75, 0.625, and 0.5 upon K extraction and reinsertion, as determined by ex situ X‐ray diffraction characterization and ab initio calculations. This work further explains the role of oxygen substitution in KVPO4+xF1−x: the oxygenation of KVPO4F leads to an anion‐disordered structure which prevents the formation of K+/vacancy orderings without electrochemical plateaus and hence to a smoother voltage profile. [ABSTRACT FROM AUTHOR]

Feasible method of quantitative determination of anionic polymers in aqueous solutions was described using poly(styrene sulfonate) and poly(acrylate) sodium salts as an example. The method consists in absorbance measurements while titrating with thiazine dye. Volume of dye solution needed to attain specified value of absorbance is linearly dependent on polymer concentration. Optimal wavelengths are 666 nm and 640 nm for Methylene Blue dye and Toluidine Blue dye, respectively. Calibration plots are straight lines (r2 > 0.99) ensuring good accuracy of the method developed. Range of measurable concentrations is dependent on chosen value of end-point absorbance. [ABSTRACT FROM AUTHOR]

Abstract: Efficient energy storage is a driving factor propelling myriads of mobile electronics, electric vehicles and stationary electric grid storage. Li‐ion batteries have realized these goals in a commercially viable manner with ever increasing penetration to different technology sectors across the globe. While these electronic devices are more evident and appealing to consumers, there has been a growing concern for micro‐to‐mega grid storage systems. Overall, the modern world demands energy in ‘terawatt’ scale. It needs a multipronged approach with alternate technologies complementing the Li‐ion batteries. One such viable approach is to design and implement Na‐ion batteries. With the uniform geographical distribution, abundance and materials economy of Na resources as well as a striking operational similarity to Li‐ion batteries, Na‐ion batteries have commercial potential, particularly for applications unrestricted by volumetric/gravimetric energy density. In pursuit of the development of Na‐ion batteries, suites of oxides, sulfides, fluorides, and polyanionic materials have been reported in addition to several organic complexes. This article gives an overview of recent progress in polyanionic framework compounds, with emphasis on high‐voltage candidates consisting of earth abundant elements. Guided by ternary phase diagrams, recently discovered and potential cathode candidates will be discussed gauging their performance, current status, and future perspectives. [ABSTRACT FROM AUTHOR]