Structural basis of ketamine action on human NMDA receptors.

Ketamine is a non-competitive channel blocker of N-methyl-D-aspartate (NMDA) receptors1. A single sub-anaesthetic dose of ketamine produces rapid (within hours) and long-lasting antidepressant effects in patients who are resistant to other antidepressants2,3. Ketamine is a racemic mixture of S- and R-ketamine enantiomers, with S-ketamine isomer being the more active antidepressant4. Here we describe the cryo-electron microscope structures of human GluN1-GluN2A and GluN1-GluN2B NMDA receptors in complex with S-ketamine, glycine and glutamate. Both electron density maps uncovered the binding pocket for S-ketamine in the central vestibule between the channel gate and selectivity filter. Molecular dynamics simulation showed that S-ketamine moves between two distinct locations within the binding pocket. Two amino acids-leucine 642 on GluN2A (homologous to leucine 643 on GluN2B) and asparagine 616 on GluN1-were identified as key residues that form hydrophobic and hydrogen-bond interactions with ketamine, and mutations at these residues reduced the potency of ketamine in blocking NMDA receptor channel activity. These findings show structurally how ketamine binds to and acts on human NMDA receptors, and pave the way for the future development of ketamine-based antidepressants.

Ultrahard bulk amorphous carbon from collapsed fullerene.

Amorphous materials inherit short- and medium-range order from the corresponding crystal and thus preserve some of its properties while still exhibiting novel properties1,2. Due to its important applications in technology, amorphous carbon with sp2 or mixed sp2-sp3 hybridization has been explored and prepared3,4, but synthesis of bulk amorphous carbon with sp3 concentration close to 100% remains a challenge. Such materials inherit the short-/medium-range order of diamond and should also inherit its superior properties5. Here, we successfully synthesized millimetre-sized samples-with volumes 103-104 times as large as produced in earlier studies-of transparent, nearly pure sp3 amorphous carbon by heating fullerenes at pressures close to the cage collapse boundary. The material synthesized consists of many randomly oriented clusters with diamond-like short-/medium-range order and possesses the highest hardness (101.9 ± 2.3 GPa), elastic modulus (1,182 ± 40 GPa) and thermal conductivity (26.0 ± 1.3 W m-1 K-1) observed in any known amorphous material. It also exhibits optical bandgaps tunable from 1.85 eV to 2.79 eV. These discoveries contribute to our knowledge about advanced amorphous materials and the synthesis of bulk amorphous materials by high-pressure and high-temperature techniques and may enable new applications for amorphous solids.

Long-term follow-up of methotrexate and cytarabine in adult patients with Langerhans cell histiocytosis.

The optimal treatment strategy for adult Langerhans cell histiocytosis (LCH) remains unclear. Our previous study demonstrated the remarkable efficacy of combined methotrexate and cytarabine (Ara-C) [MA] therapy in patients newly diagnosed with LCH, with a median follow-up of 2 years. The present article reports long-term follow-up data spanning a median of 78 months (6.5 years) from a single-arm, single-centre, prospective phase 2 clinical trial (NCT02389400) conducted between January 2014 and December 2020. Ninety-five adults with newly diagnosed LCH exhibiting multisystem disease or multifocal single-system involvement underwent MA therapy every 35 days for six cycles. Methotrexate (1 g/m2) was administered by 24 h infusion on day 1 and AraC (0.1 g/m2) by 24 h infusion for 5 days. The primary end-point was event-free survival (EFS). The median patient age was 32 years (range 18-65 years). The overall response rate was 89.5%. Seven patients in this cohort died, and 38 experienced disease reactivation. No degenerative central nervous system diseases were observed. The estimated 6-year overall survival (OS) and EFS rates were 93.2% and 55.2% respectively. Multivariate analysis revealed that risk organ (RO) involvement at baseline (hazard ratio [HR] 6.135 [95% confidence interval (CI) 1.185-32.259]; p = 0.031) and age >40 years at diagnosis (HR 7.299 [95% CI 1.056-21.277]; p = 0.042) were associated with inferior OS. RO (HR 2.604 [95% CI 1.418-4.762]; p = 0.002) and skin (HR 2.232 [95% CI 1.171-4.255]; p = 0.015) involvement at baseline were poor prognostic factors for EFS. Regarding adverse events, four patients developed a second primary malignancy. In conclusion, the MA regimen was a valid and safe therapeutic approach for adult patients newly diagnosed with LCH.

Liver involvement with Langerhans cell histiocytosis in adults.

BACKGROUND AND AIMS: Liver involvement portends poor prognosis in adults. We aimed to characterize the clinical features, liver function tests, radiologic findings, molecular profiles, therapeutic approaches and outcomes of adults patients with Langerhans cell histiocytosis (LCH) with liver involvement. METHODS: We conducted a retrospective analysis of all adults with LCH (≥ 18 years) seen at Peking Union Medical College Hospital (Beijing, China) between January 2001 and December 2022. RESULTS: Among the 445 newly diagnosed adults with LCH, 90 patients had liver involvement at diagnosis and 22 patients at relapse. The median age was 32 years (range, 18-66 years). Of 112 evaluable patients, 108 had full liver function testing, including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT), and total bilirubin and albumin. Elevated ALP was seen in 63.0% and GGT in 86.1%; 14.8% had elevated bilirubin. Next-generation sequencing of 54 patients revealed frequent BRAFN486_P490 (29.6%), BRAFV600E (18.5%), and MAP2K1 (14.8%). OUTCOMES: After a median 40 months' follow-up (range 1-168 months), 3-year progression-free survival (PFS) and overall survival were 49.7% and 86.6% respectively. In multivariable analyses, ≥3 abnormal liver function tests (HR 3.384, 95% CI 1.550-7.388, P = .002) associated with inferior PFS; immunomodulatory drug therapy (HR 0.073, 95% CI, 0.010-0.541, P = .010) correlated with superior PFS versus chemotherapy. CONCLUSIONS: In summary, elevated GGT and ALP were common in adults with LCH liver involvement. Greater than equal to 3 abnormal liver function tests predicted poor outcomes. Immunomodulatory drug therapy was associated with favorable progression-free survival compared to chemotherapy.

Gelatin-mediated gallium-doped SrHA composite coatings with sequential antimicrobial and osteogenic functions for infected bone defect repair.

In this study, gallium- and gelatin-modified strontium-doped hydroxyapatite (SrHA-Gel-Ga) bilayer coatings were prepared on titanium substrates by electrodeposition and spin-coating techniques. The results showed that gallium and gelatin were uniformly doped into the SrHA coatings, which exhibited good hydrophilicity and bioactivity. Furthermore, SrHA-Gel-Ga demonstrated good antimicrobial properties against E. coli and S. aureus, especially S. aureus. The co-doping of Sr and gelatin in the coatings was effective in mitigating the cytotoxicity of Ga. SrHA-Gel-Ga was better able to promote the adhesion, proliferation and early differentiation of MC3T3-E1 cells. This study provides a new strategy for the development of anti-infective bone repair coatings.

Casein phosphopeptide/antimicrobial peptide co-modified SrTiO3 nanotubes for prevention of bacterial infections and repair of bone defects.

Endowing titanium surfaces with multifunctional properties can reduce implant-related infections and enhance osseointegration. In this study, titanium dioxide nanotubes with strontium doping (STN) were first created on the titanium surface using anodic oxidation and hydrothermal synthesis techniques. Next, casein phosphopeptide (CCP) and an antimicrobial peptide (HHC36) were loaded into the STN with the aid of vacuum physical adsorption (STN-CP-H), giving the titanium surface a dual function of "antimicrobial-osteogenic". The surface of STN-CP-H has a suitable roughness and good hydrophilicity, which is conducive to osteoblasts. STN-CP-H had a 99 % antibacterial rate against S. aureus and E. coli and effectively prevented the growth of bacterial biofilm. Meanwhile, the antibacterial mechanism of STN-CP-H was initially explored with the help of transcriptome sequencing technology. STN-CP-H could greatly increase osteoblast adhesion, proliferation, and expression of osteogenic markers (alkaline phosphatase, runt-related transcription) when CCP and Sr worked together synergistically. In vivo, the STN-CP-H coating could effectively promote new osteogenesis around titanium implant bone and had no toxic effects on heart, liver, spleen, lung and kidney tissues. A potential anti-infection bone healing material, STN-CP-H bifunctional coating developed in this work efficiently inhibited bacterial infection of titanium implants and encouraged early osseointegration.

Boosting Zinc Storage Performance of Li3 VO4 Cathode Material for Aqueous Zinc Ion Batteries via Carbon-Incorporation: A Study Combining Theory and Experiment.

In the search for sustainable cathode materials for aqueous zinc ion batteries (AZIBs), vanadium (V)-based materials have garnered interest, primarily due to their abundance and multiple oxidation states. Among the contenders, Li3 VO4 (LiVO) stands out for its affordability, high specific capacity, and elevated ionic conductivity. However, its limited electrical conductivity results in significant resistance polarization, limiting its rate capability, especially under high currents. Through density functional theory (DFT) calculations, this study evaluates the electrochemical implications of carbon (C) incorporation within the LiVO matrix. The findings indicate that C integration significantly ameliorates the conductivity of LiVO. Moreover, C serves as a barrier, mitigating direct interactions between Zn2+ and LiVO, which in turn expedites Zn2+ diffusion. When considering various C materials for this role, glucose is emerged as the optimal candidate. The LiVO/C-glucose composite (LiVO/C-G) is observed to undergo dual phase transitions during charge-discharge cycles, resulting in an amorphous vanadium-oxygen (VO) derivative, paving the way for subsequent electrochemical reactions. Collectively, the insights pave a promising avenue for refining AZIB cathode design and performance.

Empirical Confirmation of Theoretical Predictions for Amorphous H/VO4 Cathodes: Advancing Durability and Efficiency in Zinc-Ion Batteries.

Advancing cathode materials is crucial for the broader application of aqueous zinc-ion batteries (ZIBs) in energy storage systems. This study presents amorphous H/VO4 (HVO), a novel cathode material engineered by substituting H+ for Mg2+ in Mg2VO4 (MgVO), designed to enhance performance of ZIBs. Initial exploration of MgVO through ab initio molecular dynamics (AIMD) simulations and density functional theory (DFT) calculations revealed a favorable Mg2+ and Zn2+ exchange mechanism. This mechanism notably reduces electrostatic interactions and facilitates ion diffusion within the host lattice. Building upon these findings, in this work, theoretical calculations analysis indicated that amorphous HVO offers a higher diffusion coefficient for Zn2+ ions and fewer electrostatic interactions compared to its crystalline MgVO precursor. Subsequent empirical validation is achieved by synthesizing amorphous HVO using a rapid ion-exchange process, effectively replacing Mg2+ with H+ ions. The synthesized amorphous HVO demonstrated 100% capacity retention after 18000 cycles at a current density of 2 A g-1 and exhibited exceptional rate performance. These findings underscore the significant potential of HVO cathodes to enhance the durability and efficiency of aqueous ZIBs, positioning them as promising candidates for future energy storage technologies.

Amorphous Structure Benefits in MgV2O4/V2O3 Composites for Zinc-Ion Storage: An Integration of Computational and Experimental Studies.

This study investigates the electrochemical properties of MgV2O4/V2O3 composites for Aqueous Zinc-Ion Batteries (AZIBs) using both Density Functional Theory (DFT) calculations and experimental validation. DFT analysis reveals significant electron mobility and reactivity at the MgV2O4/V2O3 interface, enhancing Zn2+ storage capabilities. This theoretical prediction is confirmed experimentally by synthesizing a novel MgV2O4/V2O3 composite that demonstrates superior electrochemical performance compared to pristine phases. Notably, the transition of the MgV2O4/V2O3 composite into an amorphous structure during electrochemical cycling is pivotal, providing enhanced diffusion pathways and increased conductivity. The composite delivers a consistent specific capacity of 330.2 mAh g-1 over 50 cycles at 0.1 A g-1 and maintains 152.7 mAh g-1 at an elevated current density of 20 A g-1 after 2000 cycles, validating the synergy between DFT insights and experimental outcomes, and underscoring the potential of amorphous structures in enhancing battery performance.

A Janus Spectrally Selective Glazing Toward All-Season Energy-Efficient Windows.

Windows offer the most promising avenue for mitigating energy consumption and reducing greenhouse gas emissions. However, the balance between comfortable natural lighting and all-season energy savings is often neglected in extensive explorations of energy-efficient windows. Herein, a Janus glazing is proposed that enables the switch of passive radiative cooling and heating under the precondition of conveying sufficient natural light. Measurement results indicate that the Janus window maintains a visible transmittance of 0.47, while possesses a near-infrared (NIR) reflectivity/absorptivity of 0.75/0.71 and a mid-infrared (MIR) emissivity of 0.94/0.13 for the cooling and heating modes, respectively. As demonstrated by the outdoor test, the Janus window realizes a reduction of 7.1 °C for room cooling and an increase of 0.4 °C for room heating compared with commercial low-e window, potentially conserving 13%-53% of the total building energy consumption across China. Meanwhile, attributed to the photothermal effect, the Janus window can elevate the surface temperature by 6.1 °C compared with the low-e window, which can effectively reduce fogging occurrences on the window surface for ensuring sunlight entrance in the cold-weather conditions. This strategy offers novel prospects for enhancing energy efficiency in diverse applications, including architectural windows, greenhouse cultivation, photovoltaic generation, etc.

Experimental Validation of Density Functional Theory Predictions on Structural Water Impact in Vanadium Oxide Cathodes for Zinc-Ion Batteries.

This study combines experimental methods with density flooding theory (DFT) calculations to investigate the enhancement of the electrochemical performance of vanadium oxide cathodes for aqueous zinc ion batteries (AZIBs) through strategic water content management. DFT predictions indicated that a moderate presence of structural water optimizes electrical conductivity and facilitates zinc ion diffusion. These theoretical insights are empirically validated by synthesizing AlVO-1.6 H2O using a hydrothermal method, which exhibited superior electrochemical properties. This material demonstrated an impressive initial capacity of 316 mAh g-1 at 0.2 A g-1, with robust capacity retention after extended cycling. Remarkably, even at an elevated current density of 10 A g-1, it sustains a capacity of 161.6 mAh g-1, while maintaining a capacity retention of 97.6% over 2000 cycles. The results confirm that adjusting the structural water content in vanadium oxides significantly boosts their electrochemical capabilities, aligning experimental outcomes with computational forecasts and showcasing a novel approach for developing high-performance cathodes in energy storage technologies.

Manifestations and outcomes of digestive tract involvement in adult Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a heterogeneous histiocytosis characterized by proliferation of Langerhans cells. While less common, manifestations of digestive tract involvement in LCH remain largely unrevealed. We conducted a retrospective analysis of demographics, clinical, endoscopic, genetic and follow-up data from 13 adult patients with pathologically confirmed gastrointestinal involvement of LCH (LCH-GI), in a single-center cohort of 465 patients. Digestive tract involvement was observed in 2.80% of LCH patients. At LCH-GI diagnosis, 7 patients (53.8%) had unifocal lesions, and 6 patients (46.2%) had multisystem disease. 6 patients (46.2%) experienced no gastrointestinal symptoms at LCH-GI onset, while others were symptomatic. Stomach was most commonly affected (61.5%), followed by esophagus (23.1%), colon (7.7%) and anus (7.7%). Endoscopic findings varied among 12 patients, including submucosal bulge (8 patients, 66.7%) and non-bulging lesions (4 patients, 33.3%) such as erosions, coarse granular mucosa, and regional abnormal coloration. Among 8 patients with genetic analysis, BRAFV600E mutation was detected in 5 patients (62.5%). The estimated 1-year overall survival rate was 91.7%. Progression-free survival of patients with submucosal bulges under endoscopy was significantly better than those with non-bulging lesions. This study presents 13 cases of LCH with digestive tract involvement. We emphasize the importance of endoscopy and biopsy for pathological examination of lesions such as submucosal bulges and erosions under endoscopy to assist in early detection of LCH. Comprehensive systemic assessment and regular endoscopic monitoring are essential in patient management. Treatment should be individualized with dynamic adjustments during follow-up.

Synergistic Enhancement on the Sensing Performance of Mixed Potential NH3 Sensors by Fe and Mo Codoping into BiVO4.

Mixed potential ammonia (NH3) sensors with the Fe- and Mo-codoped BiVO4 sensing electrode and Ag reference electrode based on the yttria-stabilized zirconia solid electrolyte were developed. Fe- and Mo-doped BiVO4 sensing materials were prepared using solution combustion synthesis and then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). It was observed that Fe doping could greatly improve the response rate, while Mo doping could enhance the response signal (ΔU) and sensitivity. Based on the optimal doping ratio of Fe and Mo each, the synergistic enhancement of the performance by Fe and Mo codoping was investigated. The sensor coated by BiV0.75Fe0.2Mo0.05Oδ materials exhibited a prominent sensing performance to a low concentration of 10-50 ppm of NH3 at 525 °C with the outstanding sensitivity of -148.988 mV/decade. Fe and Mo doping also improved the selectivity of the sensor to NH3, with the relative deviations less than ±8% of other typical gases' interference including NO, NO2, CO, CO2, and CH4. Besides, the sensor showed good resistance to fluctuations in the oxygen concentration and favorable stability against changes in the water vapor concentration. In addition, the sensor also exhibited good long-term stability. The mixed potential response mechanism was further discussed and analyzed through polarization curves as well as through gas chromatography and infrared absorption spectroscopy.

Chelerythrine induces apoptosis and ferroptosis through Nrf2 in ovarian cancer cells.

Ovarian cancer is a prevalent malignancy in the female reproductive system, representing a significantly fatal and incurable tumor. Chelerythrine (CHE), a natural benzopyridine alkaloid, has demonstrated a broad spectrum of anticancer activities. Nevertheless, the ovarian cancer inhibitory impact of CHE remains unclear. In this study, we investigated the cytotoxic mechanism and potential targets of CHE on in vitro cultures of A2780 and SKOV3 cells derived from ovarian cancer. Additionally, in vivo experiments were conducted to confirm the suppressive impact of CHE on tumor growth in nude mice. The findings revealed that CHE impeded the growth of A2780 and SKOV3 cells in a concentration-time-dependent manner and significantly suppressed the development of tumors in nude mice. CHE elevated the level of oxidative stress in tumor cells, prompted cell cycle halt in the S phase, and increased their mitochondrial membrane potential. Western blotting results demonstrated that CHE could modulate the expression of proteins associated with apoptotic and ferroptosis processes in A2780 and SKOV3 cells. Nrf2 was verified to be an upstream key target mediating the inhibitory impact of CHE on ovarian cancer cells. In summary, CHE exerts its anti-cancer effects on ovarian cancer by modulating Nrf2, inhibiting cellular proliferation, and promoting apoptosis and ferroptosis.

Nomogram for intraoperatively acquired pressure injuries in children undergoing cardiac surgery with cardiopulmonary bypass: a retrospective study.

BACKGROUND: We aimed to develop and validate a nomogram for predicting the risk of intraoperatively acquired pressure injuries (IAPIs) in children undergoing cardiac surgery with cardiopulmonary bypass (CPB). METHODS: This study retrospectively included 208 children aged 21 days to 8 years who underwent cardiac surgery with CPB in a tertiary hospital in China between January 2020 and October 2023. All patients' data were collected from the hospital's medical record system and randomly divided into the training (n = 146) and validation (n = 62) cohorts by a ratio of 7:3. Logistic regression analysis was conducted in the training cohort to identify independent risk factors and establish the nomogram. Finally, calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA) were performed in both cohorts to validate the predictive ability of the nomogram. RESULTS: 43 (14.7%) children developed IAPIs. Multivariate analysis showed that low Braden Q scores, use of steroids, skin abnormalities, and low intraoperative SpO2 were independent risk factors for IAPIs. A nomogram integrating the 4 factors was established. The areas under the curve (AUCs) of the nomogram were 0.836 and 0.903 in the training and validation cohorts, respectively. Furthermore, calibration curves and DCA demonstrated good calibration and clinical applicability of the nomogram. CONCLUSION: We constructed a reliable nomogram based on specific risk factors for children undergoing cardiac surgery with CPB, which could be used as an effective and convenient tool for prevention of IAPIs.

Synergistic Theoretical and Experimental Insights into NH4+-Enhanced Vanadium Oxide Cathodes for Aqueous Zinc-Ion Batteries.

This study explores the enhancement of aqueous zinc-ion batteries (AZIBs) using ammonium-enhanced vanadium oxide cathodes. Density Functional Theory (DFT) calculations reveal that NH4+ incorporation into V6O16 lattices significantly facilitates Zn2+ ion diffusion by reducing electrostatic interactions, acting as a structural lubricant. Subsequent experimental validation using (NH4)2V6O16 cathodes synthesized via a hydrothermal method corroborates the DFT findings, demonstrating remarkable electrochemical stability with a capacity retention of 90% after 2000 cycles at 5 A g-1. These results underscore the potential of NH4+ in improving the performance and longevity of AZIBs, providing a pathway for sustainable energy storage solutions.

Hazel Leaf Polyphenol Extract Alleviated Cisplatin-Induced Acute Kidney Injury by Reducing Ferroptosis through Inhibiting Hippo Signaling.

Derived from hazelnuts, hazel leaf has been utilized in traditional folk medicine for centuries in countries such as Portugal, Sweden, and Iran. In our previous investigations, we conducted a preliminary assessment of the hazel leaf polyphenol extract (referred to as ZP) and identified nine compounds, such as kaempferol and chlorogenic acid, in its composition. ZP has shown promising properties as an antioxidant and anti-inflammatory agent. Our research has revealed that ZP has protective effects against cisplatin-induced acute kidney injury (AKI). We conducted a comprehensive examination of both the pathological and ultrastructural aspects and found that ZP effectively ameliorated renal tissue lesions and mitigated mitochondrial damage. Moreover, ZP significantly suppressed malondialdehyde levels while increasing glutathione and catalase concentrations in the kidneys of AKI-induced mice. ZP decreased the number of apoptotic cells and decreased pro-apoptotic protein expression in the kidneys of mice and human renal tubular epithelial cells (HK-2). Furthermore, treatment with ZP increased the levels of proteins marking anti-ferroptosis, such as GPX4, FTH1, and FSP1, in experiments both in vivo and in vitro. We elucidated the underlying mechanisms of ZP's actions, revealing its inhibitory effect on Yap phosphorylation and its regulation of Lats expression, which exert a protective influence on the kidneys. Furthermore, we found that inhibiting the Hippo pathway compromised ZP's nephroprotective effects in both in vitro and in vivo studies. In summary, this research shows that ZP exhibits renoprotective properties, effectively reducing oxidative damage, apoptosis, and ferroptosis in the kidneys by targeting the Hippo pathway.

Analysis of Polyphenol Extract from Hazel Leaf and Ameliorative Efficacy and Mechanism against Hyperuricemia Zebrafish Model via Network Pharmacology and Molecular Docking.

Hazel leaf, a by-product of hazelnuts, is commonly used in traditional folk medicine in Portugal, Sweden, Iran and other regions for properties such as vascular protection, anti-bleeding, anti-edema, anti-infection, and pain relief. Based on our previous studies, the polyphenol extract from hazel leaf was identified and quantified via HPLC fingerprint. The contents of nine compounds including kaempferol, chlorogenic acid, myricetin, caffeic acid, p-coumaric acid, resveratrol, luteolin, gallic acid and ellagic acid in hazel leaf polyphenol extract (ZP) were preliminary calculated, among which kaempferol was the highest with 221.99 mg/g, followed by chlorogenic acid with 8.23 mg/g. The inhibition of ZP on α-glucosidase and xanthine oxidase activities was determined via the chemical method, and the inhibition on xanthine oxidase was better. Then, the effect of ZP on hyperuricemia zebrafish was investigated. It was found that ZP obviously reduced the levels of uric acid, xanthine oxidase, urea nitrogen and creatinine, and up-regulated the expression ofOAT1 and HPRT genes in hyperuricemia zebrafish. Finally, the targeted network pharmacological analysis and molecular docking of nine polyphenol compounds were performed to search for relevant mechanisms for alleviating hyperuricemia. These results will provide a valuable basis for the development and application of hazel leaf polyphenols as functional ingredients.

"Dual- Engineering" Strategy to Regulate NH4 V4 O10 as Cathodes for High-Performance Aqueous Zinc Ion Batteries.

Aqueous zinc ion batteries (AZIBs) have attracted attention as a promising candidate for secondary battery energy storage due to their safety and environmental benefits. However, the vanadium-based cathode material NH4 V4 O10 has the problem of structural instability. In this paper, it is found by density functional theory calculation that excessive NH4 + located in the interlayer will repel the Zn2+ during the process of Zn2+ insertion. This results in the distortion of the layered structure, further affects the diffusion of Zn2+ and reduces the reaction kinetics. Therefore, part of the NH4 + is removed by heat treatment. In addition, the introduction of Al3+ into the material by hydrothermal method is able to further enhance its zinc storage properties. This dual-engineering strategy shows excellent electrochemical performance (578.2 mAh g-1 at 0.2 A g-1 ). This study provides valuable insights for the development of high performance AZIBs cathode materials.

Polypyrrole-Doped NH4 V3 O8 with Oxygen Vacancies as High-Performance Cathode Material for Aqueous Zinc-Ion Batteries.

The inherent slow diffusion dynamics of aqueous zinc-ion batteries (AZIBs) act as a significant hindrance to their universal utilization as energy storage systems, largely attributed to the scarcity of superior cathode materials. In this study, a novel method that amalgamates oxygen defect engineering and polymer intercalation, guided by theoretical computations, to confront this challenge, is introduced. This approach begins with density functional theory calculations, demonstrating that the shielding effect rendered by polypyrrole (PPy) between NH4 V3 O8 (NVO) layers, along with the cooperative influence of oxygen defects (Od ), optimizes the kinetic transport of Zn2+ . Leveraging these theoretical outcomes, a two-step hydrothermal synthesis procedure is devised to fabricate PPy-intercalated NVO embedded with Od (NVO-Od @PPy). The empirical findings corroborate the theoretical predictions, showcasing that the NVO-Od @PPy//Zn system manifests exceptional cycling stability. Specifically, the NVO-Od @PPy electrode delivers an optimal reversible capacity, yielding 421 mAh g-1 at a current density of 0.1 A g-1 . Remarkably, even at an elevated current density of 10 A g-1 , it sustains a capacity of 175.7 mAh g-1 , while maintaining a capacity retention of 99% over 1000 cycles. This research provides pivotal insights for the engineering of high-performing cathode materials for AZIBs, paving the way for their future advancements.