Structure-Controlled Carbon Hosts for Dendrite-Free Aqueous Zinc Batteries.

The surging demand for environmental-friendly and safe electrochemical energy storage systems has driven the development of aqueous zinc (Zn)-ion batteries (ZIBs). However, metallic Zn anodes suffer from severe dendrite growth and large volume change, resulting in a limited lifetime for aqueous ZIB applications. Here, it is shown that 3D mesoporous carbon (MC) with controlled carbon and defect configurations can function as a highly reversible and dendrite-free Zn host, enabling the stable operation of aqueous ZIBs. The MC host has a structure-controlled architecture that contains optimal sp2 -carbon and defect sites, which results in an improved initial nucleation energy barrier and promotes uniform Zn deposition. As a consequence, the MC host shows outstanding Zn plating/stripping performance over 1000 cycles at 2 mA cm-2 and over 250 cycles at 6 mA cm-2 in asymmetric cells. Density functional theory calculations further reveal the role of the defective sp2 -carbon surface in Zn adsorption energy. Moreover, a full cell based on Zn@MC900 anode and V2 O5 cathode exhibits remarkable rate performance and cycling stability over 3500 cycles. These results establish a structure-mechanism-performance relationship of the carbon host as a highly reversible Zn anode for the reliable operation of ZIBs.

Impact of intravesical administration of tranexamic acid on gross hematuria in the emergency department: A before-and-after study.

INTRODUCTION: Local applications of tranexamic acid (TXA) have been effective in treating various hemorrhagic conditions. In patients with gross hematuria, the main treatment in the emergency department (ED) is continuous bladder irrigation (CBI). However, CBI has no pharmacological effects except blood clot removal from dilution. The aim of this study was to evaluate the impact of the intravesical TXA injection before CBI. METHODS: This study was a before-and-after, retrospective, and single-center study. The target population was hematuria patients who received CBI via a 3-way Foley catheter. As the intervention procedure, 1000 mg of TXA was injected through the Foley catheter and after 15 min, the Foley catheter was declamped and CBI started. Since the intervention started in March 2022, the patients from March 2022 to August 2022 were assigned to the after group and the patients from March 2021 to August 2021 were assigned to the before group. The primary outcomes were the length of stay in the ED and duration of Foley catheter placement. The secondary outcomes were the admissions and the revisits for CBI within 48 h after discharge. RESULTS: The numbers of patients in the before group and after group were 73 and 86, respectively. The median length of stay in the ED was shorter in the intervention group than in the group not treated with TXA (274 min vs. 411 mins, P < 0.001). The median duration of Foley catheter placement was also shorter in the intervention group than not treated with TXA (145 min vs. 308 mins, P < 0.001). The revisits after ED discharge were lower in the after group than in the before group (2.3% vs. 12.3%, P = 0.031). There was a trend for lower admissions in the TXA treatment group than before group (29.1% vs. 45.2%, P = 0.052). CONCLUSION: After the TXA intervention, reduction in the length of stay in the ED, the duration of Foley catheter placement, and the revisits after ED discharge was observed.

Ruminococcus gnavus ameliorates atopic dermatitis by enhancing Treg cell and metabolites in BALB/c mice.

BACKGROUND: Ruminococcus gnavus (R. gnavus) are mucin-degrading gut bacteria that play a key role in the early colonization of the gut by serving as endogenous sources of nutrients. They can also influence immune development. We had previously reported a lower abundance of R. gnavus in infants with atopic dermatitis (AD) compared with that in healthy subjects. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of orally administered R. gnavus on antibiotic treatment-induced gut dysbiosis (and the underlying mechanism) in a mouse model of AD. METHODS: Four-week-old female BALB/C mice were administered antibiotic cocktails for 2 weeks. R. gnavus was orally administered throughout the study duration. At 6 weeks of age, AD was induced by epidermal sensitization with ovalbumin. AD phenotypes and systemic and gut immune responses were investigated. RESULTS: Orally administered R. gnavus significantly reduced AD-associated parameters (i.e., transepidermal water loss, clinical score, total serum immunoglobulin (Ig) E level, OVA-specific IgE level, and skin inflammation). R. gnavus treatment also resulted in significant downregulation of T helper 2-related cytokine mRNA and upregulation of interleukin (IL)-10 and Foxp3 in the skin. The population of CD4+ FOXP3+ T cells in mesenteric- and skin-draining lymph nodes and butyrate levels in the cecum increased in R. gnavus-administered AD mice. CONCLUSIONS: Immune modulation by orally administered R. gnavus may alleviate AD symptoms through the enhancement of regulatory T-cell counts and short-chain fatty acids production in AD mice.

In Staphylococcus aureus, the Particulate State of the Cell Envelope Is Required for the Efficient Induction of Host Defense Responses.

Upon microbial infection, host immune cells recognize bacterial cell envelope components through cognate receptors. Although bacterial cell envelope components function as innate immune molecules, the role of the physical state of the bacterial cell envelope (i.e., particulate versus soluble) in host immune activation has not been clearly defined. Here, using two different forms of the staphylococcal cell envelope of Staphylococcus aureus RN4220 and USA300 LAC strains, we provide biochemical and immunological evidence that the particulate state is required for the effective activation of host innate immune responses. In a murine model of peritoneal infection, the particulate form of the staphylococcal cell envelope (PCE) induced the production of chemokine (C-X-C motif) ligand 1 (CXCL1) and CC chemokine ligand 2 (CCL2), the chemotactic cytokines for neutrophils and monocytes, respectively, resulting in a strong influx of the phagocytes into the peritoneal cavity. In contrast, compared with PCE, the soluble form of cell envelope (SCE), which was derived from PCE by treatment with cell wall-hydrolyzing enzymes, showed minimal activity. PCE also induced the secretion of calprotectin (myeloid-related protein 8/14 [MRP8/14] complex), a phagocyte-derived antimicrobial protein, into the peritoneal cavity at a much higher level than did SCE. The injected PCE particles were phagocytosed by the infiltrated neutrophils and monocytes and then delivered to mediastinal draining lymph nodes. More importantly, intraperitoneally (i.p.) injected PCE efficiently protected mice from S. aureus infection, which was abolished by the depletion of either monocytes/macrophages or neutrophils. This study demonstrated that the physical state of bacterial cells is a critical factor for efficient host immune activation and the protection of hosts from staphylococcal infections.

Delamination-Free Multifunctional Separator for Long-Term Stability of Lithium-Ion Batteries.

Next-generation lithium-ion batteries (LIBs) that satisfy the requirements for an electric vehicle energy source should demonstrate high reliability and safety for long-term high-energy-density operation. This inevitably calls for a novel approach to advance major components such as the separator. Herein, a separator is designed and fabricated via application of multilayer functional coating on both sides of a polyethylene separator. The multilayer-coated separator (MCS) has a porous structure that does not interfere with lithium ion diffusion and exhibits superior heat resistance, high electrolyte uptake, and persistent adhesion with the electrode. More importantly, it enables high capacity retention and reduced impedance build up during cycling when used in a coin or pouch cell. These imply its promising application in energy sources requiring long-term stability. Fabrication of the MCS without the use of organic solvents is not only environmentally beneficial but also effective at cost reduction. This approach paves the way for the separator, which has long been considered an inactive major component of LIBs, to become an active contributor to the energy density toward achieving longer cycle stability.

Effect of Electrical Vagus Nerve Stimulation on Cerebral Blood Flow and Neurological Outcome in Asphyxial Cardiac Arrest Model of Rats.

BACKGROUND: Vagus nerve stimulation (VNS) during post-resuscitation may increase recovery of cerebral blood flow (CBF) and reduce neurological injury. OBJECTIVE: This study was designed to investigate the effect of electrical VNS on neurological outcomes following cardiac arrest (CA). METHODS: Male Sprague-Dawley rats (n = 48) were subjected to the asphyxial CA model and blindly allocated to the VN isolation (CA + VN isolation) or VNS group (CA + VNS group). Cardiopulmonary resuscitation was initiated 450 s after pulseless electrical arrest, and the left cervical vagus nerve was electrically stimulated (0.05 mA, 1 Hz) for 3 h in the CA + VNS group. The neurological deficit score (NDS) and overall performance category (OPC) were assessed at 24 h after resuscitation, and histological injury of the hippocampus was evaluated. Independent experiments were performed to evaluate the effect of VNS on global cortical CBF after resuscitation using laser speckle Doppler imaging through a thinned skull window from pre-arrest to 6 h after resuscitation. RESULTS: The baseline characteristics were not significantly different between the two groups. The NDS was significantly higher, and the OPC was substantially lower in the CA + VNS group (p = 0.022 and p = 0.049, respectively) supported by decrease in histological injury of the hippocampal CA1 region. CBF in the early period of post-return of spontaneous circulation (ROSC) was significantly higher in the CA + VNS group (p < 0.05 at post-ROSC 2 h and 4 h), and 4-hydroxynonenal was significantly lower in the CA + VNS group (p = 0.026). CONCLUSIONS: VNS improved cerebral perfusion and neurological outcomes at 24 h after ROSC in an asphyxial CA model of rats.

Impact of bacteremia prediction rule in CAP: Before and after study.

OBJECTIVE: In cases of community acquired pneumonia (CAP), it has been known that blood cultures have low yields and rarely affect clinical outcomes. Despite many studies predicting the likelihood of bacteremia in CAP patients, those results have been rarely implemented in clinical practice, and use of blood culture in CAP is still increasing. This study evaluated impact of implementing a previously derived and validated bacteremia prediction rule. METHODS: In this registry-based before and after study, we used piecewise regression analysis to compare the blood culture rate before and after implementation of the prediction rule. We also compared 30-day mortality, emergency department (ED) length of stay, time-interval to initial antibiotics after ED arrival, and any changes to the antibiotics regimen as results of the blood cultures. In subgroup analysis, we compared two groups (with or without the use of the prediction rule) after implementation period, using propensity score matching. RESULTS: Following the implementation, the blood culture rate declined from 85.5% to 78.1% (P=0.003) without significant changes in 30-day mortality and antibiotics regimen. The interval to initial antibiotics (231min vs. 221min, P=0.362) and length of stay (1019min vs. 954min, P=0.354) were not significantly changed. In subgroup analysis, the group that use the prediction rule showed 25min faster antibiotics initiation (P=0.002) and 48min shorter length of stay (P=0.007) than the group that did not use the rule. CONCLUSION: Implementation of the bacteremia prediction rule in CAP patients reduced the blood culture rate without affecting the 30-day mortality and antibiotics regimen.

Incidence and risk factors of delayed intracranial hemorrhage in the emergency department.

OBJECTIVES: This study was performed to identify the risk factors for delayed intracranial hemorrhage and develop a risk stratification system for disposition of head trauma patients with negative initial brain imaging. METHODS: The data source was National Health Insurance Service-National Sample Cohort of Korea. We analyzed adult patients presenting to the ER from January 2004 to September 2012, who underwent brain imaging and discharged with or without short-term observation no longer than two days. The primary outcome was defined as any intracranial bleeding within a month defined by a new appearance of any of the diagnostic codes for intracranial hemorrhage accompanied by a new claim for brain imaging(s) within a month of the index visit. We performed a multivariable logistic regression analysis and built a parsimonious model for variable selection to develop a simple scoring system for risk stratification. RESULTS: During the study period, a total of 19,723 head injury cases were identified from the cohort and a total of 149 cases were identified as having delayed intracranial hemorrhage within 30days. In multivariable logistic regression model, old age, craniofacial fracture, neck injury, diabetes mellitus and hypertension were independent risk factors for delayed intracranial hemorrhage. We constructed the parsimonious model included age, craniofacial fracture and diabetes mellitus. The score showed area under the curve of 0.704 and positive predictive value of the score system was 0.014 when the score≥2. CONCLUSIONS: We found old age, associated craniofacial fracture, any neck injury, diabetes mellitus and hypertension are the independent risk factors of delayed intracranial hemorrhage.

Automated Vision-Based Detection of Cracks on Concrete Surfaces Using a Deep Learning Technique.

At present, a number of computer vision-based crack detection techniques have been developed to efficiently inspect and manage a large number of structures. However, these techniques have not replaced visual inspection, as they have been developed under near-ideal conditions and not in an on-site environment. This article proposes an automated detection technique for crack morphology on concrete surface under an on-site environment based on convolutional neural networks (CNNs). A well-known CNN, AlexNet is trained for crack detection with images scraped from the Internet. The training set is divided into five classes involving cracks, intact surfaces, two types of similar patterns of cracks, and plants. A comparative study evaluates the successfulness of the detailed surface categorization. A probability map is developed using a softmax layer value to add robustness to sliding window detection and a parametric study was carried out to determine its threshold. The applicability of the proposed method is evaluated on images taken from the field and real-time video frames taken using an unmanned aerial vehicle. The evaluation results confirm the high adoptability of the proposed method for crack inspection in an on-site environment.

Functionalization effect on a Pt/carbon nanotube composite catalyst: a first-principles study.

Chemical interactions between Pt and both pristine and defective carbon nanotubes (CNTs) that were functionalized with various surface functional groups, including atomic oxygen (-O), atomic nitrogen (-N), hydroxyl (-OH) and amine (-NH2) groups, were investigated through first-principles calculations. Our calculations suggest that the oxygen or nitrogen of the surface functional group can promote better structural stability of a Pt/CNT complex in terms of the binding energy enhancement between Pt and CNTs. Enhanced binding of the Pt/CNT complex would improve the long-term durability of the complex and thus enhance the catalytic activity of Pt catalysts supported on CNTs. Among the functional groups investigated, atomic nitrogen resulted in the most consistent increase in the Pt binding energies on pristine or defective CNTs. Moreover, atomic nitrogen decoration on the surface of CNTs rather than substitution into the CNTs appears to be more desirable. A d-band centre analysis and H2 adsorption calculations also revealed that the catalytic activity of Pt can be improved via efficient functionalization of the CNT support.

Cordycepin Suppresses Thymic Stromal Lymphopoietin Expression via Blocking Caspase-1 and Receptor-Interacting Protein 2 Signaling Pathways in Mast Cells.

Cordycepin (3'-deoxyadenosine) is one of the active components isolated from Cordyceps militaris, and has been shown to have anti-inflammatory, anti-oxidant, anti-aging, and anti-cancer effects. Mast cell-derived thymic stromal lymphopoietin (TSLP) plays an important role in the pathogenesis of allergic inflammatory reactions. Here, we investigated the regulatory effect and mechanisms of cordycepin on the expression of TSLP in the human mast cell line, HMC-1 cells, and in the human keratinocyte cell line, HaCaT cells. Cordycepin significantly decreased the production and mRNA expression of TSLP through the inhibition of caspase-1 and nuclear factor-κB activation. Cordycepin also significantly reduced the phosphorylation of receptor-interacting protein 2 and inhibitory kappa B (IκB) kinase ß. Cordycepin significantly decreased the production and mRNA expression of interleukin (IL)-8, IL-1ß, IL-6, and tumor necrosis factor-α in activated HMC-1 cells. Moreover, cordycepin significantly decreased the levels of TSLP in activated HaCaT cells. Our studies suggest that cordycepin can be applied to the treatment of allergic inflammatory diseases exacerbated by TSLP.

External validation of the STONE score and derivation of the modified STONE score.

OBJECTIVE: The STONE score is a clinical prediction rule for the presence of uncomplicated ureter stones with a low probability of acutely important alternative findings. This study performed an external validation of the STONE score, focusing on the Korean population, and a derivation of the modified STONE score for better specificity and sensitivity. METHODS: We retrospectively reviewed medical records of patients complaining of flank pain at a single emergency department from January 2013 to December 2014. Patients were categorized into 3 groups according to their STONE score. The prevalence of ureter stones and other alternative findings were calculated in each group. We derived a modified STONE score based on a multivariable analysis and performed an interval validation. RESULTS: From the 700 patients included in the analysis, 555 patients (79%) had a ureter stone. The area under the receiver operating characteristic curve of the STONE score was 0.92. The sensitivity of the high stone score was 0.56. In the modified STONE score, nausea, vomiting, and racial predictors were substituted by C-reactive protein and previous stone history. The area under the receiver operating characteristic curve and sensitivity of the modified STONE score in the internal validation group significantly increased to 0.94 and 0.80, respectively. CONCLUSION: The STONE score can be used to predict a ureter stone with a low probability of other alternative findings. The modified STONE score might increase the diagnostic performance in suspicious urinary stone cases. KEY POINTS: We performed external validation of the STONE score and derivation of the modified STONE score. This scoring system could help the clinicians with radiation reducing decision making.

A ResNet-LSTM hybrid model for predicting epileptic seizures using a pretrained model with supervised contrastive learning.

In this paper, we propose a method for predicting epileptic seizures using a pre-trained model utilizing supervised contrastive learning and a hybrid model combining residual networks (ResNet) and long short-term memory (LSTM). The proposed training approach encompasses three key phases: pre-processing, pre-training as a pretext task, and training as a downstream task. In the pre-processing phase, the data is transformed into a spectrogram image using short time Fourier transform (STFT), which extracts both time and frequency information. This step compensates for the inherent complexity and irregularity of electroencephalography (EEG) data, which often hampers effective data analysis. During the pre-training phase, augmented data is generated from the original dataset using techniques such as band-stop filtering and temporal cutout. Subsequently, a ResNet model is pre-trained alongside a supervised contrastive loss model, learning the representation of the spectrogram image. In the training phase, a hybrid model is constructed by combining ResNet, initialized with weight values from the pre-trained model, and LSTM. This hybrid model extracts image features and time information to enhance prediction accuracy. The proposed method's effectiveness is validated using datasets from CHB-MIT and Seoul National University Hospital (SNUH). The method's generalization ability is confirmed through Leave-one-out cross-validation. From the experimental results measuring accuracy, sensitivity, and false positive rate (FPR), CHB-MIT was 91.90%, 89.64%, 0.058 and SNUH was 83.37%, 79.89%, and 0.131. The experimental results demonstrate that the proposed method outperforms the conventional methods.

A molecular dynamics simulation study on the initial stage of Si(001) oxidation under biaxial strain.

We have studied the very early stage of the room temperature oxidation of the externally-strained Si(001) surface using molecular dynamics simulation. It was found that the different treatment history of the sample under the same strain resulted in the difference in the number density of dimer. The as-prepared samples of different treatment history with 12.15% strain were used to investigate the initial oxidation behavior of Si(001). 500 times of independent deposition of single oxygen molecule onto the random position of clean Si(001) surface was simulated. Oxidation behavior was statistically analyzed for various dimer density of the surface which is dependent on strain-treatment history. Oxygen uptake and penetration depth profile showed an important role of dimers on the surface oxidation behavior.

The effect of shoulder muscle succinylcholine injection on the foreleg raising power: Sion's local paralysis.

Objective: We examined the change in foreleg raising power after Sion's local paralysis (SLP) with succinylcholine in the shoulder muscle. Methods: A randomized, double blind, placebo-controlled, porcine study was designed and performed at a research institution. Ten male Korean native pigs were randomized into an intervention group (n = 5) and a control group (n = 5). The injection points were in the middle of the left trapezius muscle and the middle of the left deltoid muscle. The control group received 2 ml normal saline (NS), 1 ml injected in each point. The intervention group received 0.4 mg/kg succinylcholine diluted to 2 ml in NS, and 1 ml was injected in each point. To represent the foreleg raising power, the height of the left forelegs from baseline (experiment table) was measured. We measured the foreleg height and oxygen saturation at -4, -2, 0, +2, +4, +6, +8, +10, +20, +30, and +60 min. Results: After SLP, foreleg height immediately declined in the intervention group. It recovered slightly for a few minutes and declined from 4 to 8 min. In the control group, foreleg height was relatively similar throughout the study period. A repeated-measure analysis of variance revealed a significant group × time interaction (F10,80 = 2.37, P = 0.017), a significant main effect for group (F1,8 = 6.25, P = 0.037), and a significant main effect for time (F10,80 = 4.41, P < 0.001). Post hoc analysis demonstrated that the intervention group showed significantly less foreleg raising power than the control group at 0, 4, 6, 8, 20, and 30 min (P < 0.05). Conclusions: Compared with the control group, the foreleg raising power in the intervention group immediately decreased significantly and persisted for a period after SLP, without hypoxia, in a pig model.

Unexpected Penetration of CO Molecule into Zeolitic Micropores Almost Plugged by CuCl via π-Complexation of CO-CuCl.

Carbon monoxide (CO) is a key reactant in several Fischer-Tropsch processes, including those used in light olefin and methanol syntheses. However, it is highly toxic and causes serious poisoning of noble metal catalysts. Thus, a solid adsorbent that can selectively capture CO, especially at low concentrations, is required. In this study, zeolite Y-based adsorbents in which Cu(I) ions occupy the supercage cation sites (CuCl/Y) are prepared via solid-state ion exchange. Volumetric adsorption measurements reveal that the Cu(I) ions significantly enhance CO adsorption in the low-pressure range by π-complexation. Furthermore, unexpected molecular sieving behavior, with extremely high CO/CO2 selectivity, is observed when excess CuCl homogeneously covers the zeolite pore structures. Thus, although CO has a larger kinetic diameter, it can penetrate the zeolite supercage while smaller molecules (i.e., Ar and CO2) cannot. Density functional theory calculations reveal that CO molecules can remain adsorbed in pseudoblocked pores by CuCl, thanks to the strong interaction of C 2p and Cu 3d states, resulting in the high CO/CO2 selectivity. One of the prepared adsorbents, CuCl/Y with 50 wt % CuCl, is capable of selectively capturing 3.04 mmol g-1 of CO with a CO/CO2 selectivity of >3370.

Colossal Dielectric Perovskites of Calcium Copper Titanate (CaCu3 Ti4 O12 ) with Low-Iridium Dopants Enables Ultrahigh Mass Activity for the Acidic Oxygen Evolution Reaction.

Oxygen evolution reaction (OER) under acidic conditions becomes of significant importance for the practical use of a proton exchange membrane (PEM) water electrolyzer. In particular, maximizing the mass activity of iridium (Ir) is one of the maiden issues. Herein, the authors discover that the Ir-doped calcium copper titanate (CaCu3Ti4O12, CCTO) perovskite exhibits ultrahigh mass activity up to 1000 A gIr -1 for the acidic OER, which is 66 times higher than that of the benchmark catalyst, IrO2 . By substituting Ti with Ir in CCTO, metal-oxygen (M-O) covalency can be significantly increased leading to the reduced energy barrier for charge transfer. Further, highly polarizable CCTO perovskite referred to as "colossal dielectric", possesses low defect formation energy for oxygen vacancy inducing a high number of oxygen vacancies in Ir-doped CCTO (Ir-CCTO). Electron transfer occurs from the oxygen vacancies and Ti to the substituted Ir consequentially resulting in the electron-rich Ir and -deficient Ti sites. Thus, favorable adsorptions of oxygen intermediates can take place at Ti sites while the Ir ensures efficient charge supplies during OER, taking a top position of the volcano plot. Simultaneously, the introduced Ir dopants form nanoclusters at the surface of Ir-CCTO, which can boost catalytic activity for the acidic OER.

First-pass metabolism of decursin, a bioactive compound of Angelica gigas, in rats.

Decursin is considered the major bioactive compound of Angelica gigas roots, a popular Oriental herb and dietary supplement. In this study, the pharmacokinetics of decursin and its active metabolite, decursinol, were evaluated after the administration of decursin in rats. The plasma concentration of decursin decreased rapidly, with an initial half-life of 0.05 h. It was not detectable at 1 h after intravenous administration at an area under the plasma concentration-time curve of 1.20 µg · mL-1·h, whereas the concentration of decursinol increased rapidly reaching a maximum concentration of 2.48 µg · mL-1 at the time to maximum plasma concentration of 0.25 h and an area under the plasma concentration-time curve of 5.23 µg · mL-1·h. Interestingly, after oral administration of decursin, only decursinol was present in plasma, suggesting an extensive hepatic first-pass metabolism of decursin. The extremely low bioavailability of decursin after its administration via the hepatic portal vein (the fraction of dose escaping first-pass elimination in the liver, FH = 0.11) is indicative of extensive hepatic first-pass metabolism of decursin, which was confirmed by a tissue distribution study. These findings suggest that decursin is not directly associated with the bioactivity of A. gigas and that it may work as a type of natural prodrug of decursinol.

A 3D Hierarchical Host with Enhanced Sodiophilicity Enabling Anode-Free Sodium-Metal Batteries.

Sodium-metal batteries (SMBs) are considered as a compliment to lithium-metal batteries for next-generation high-energy batteries because of their low cost and the abundance of sodium (Na). Herein, a 3D nanostructured porous carbon particle containing carbon-shell-coated Fe nanoparticles (PC-CFe) is employed as a highly reversible Na-metal host. PC-CFe has a unique 3D hierarchy based on sub-micrometer-sized carbon particles, ordered open channels, and evenly distributed carbon-coated Fe nanoparticles (CFe) on the surface. PC-CFe achieves high reversibility of Na plating/stripping processes over 500 cycles with a Coulombic efficiency of 99.6% at 10 mA cm-2 with 10 mAh cm-2 in Na//Cu asymmetric cells, as well as over 14 400 cycles at 60 mA cm-2 in Na//Na symmetric cells. Density functional theory calculations reveal that the superior cycling performance of PC-CFe stems from the stronger adsorption of Na on the surface of the CFe, providing initial nucleation sites more favorable to Na deposition. Moreover, the full cell with a PC-CFe host without Na metal and a high-loading Na3 V2 (PO4 )3 cathode (10 mg cm-2 ) maintains a high capacity of 103 mAh g-1 at 1 mA cm-2 even after 100 cycles, demonstrating the operation of anode-free SMBs.