The impact of brominated flame retardants (BFRs) on pulmonary function in US adults: a cross-sectional study based on NHANES (2007-2012).

Brominated flame retardants (BFRs) are a group of chemicals widely used in various applications to prevent or slow down the spread of fire. However, they have adverse effects on human health. There is a relative scarcity of population-based studies regarding BFRs, particularly their impact on the respiratory system. This study aimed to investigate the influence of BFRs on pulmonary function using data from the National Health and Nutrition Examination Survey. The study found that elevated serum concentrations of certain BFRs were associated with pulmonary ventilatory dysfunction. Adjusted analyses revealed positive correlations between PBDE47, PBDE183, and PBDE209 concentrations and ventilatory dysfunction. The analysis of mixed BFRs showed a positive relationship with pulmonary ventilation dysfunction, with PBDE47 making the most significant contribution. Our study demonstrates that both individual and combined BFRs exposure can lead to impaired pulmonary ventilation function. These findings provide evidence of the adverse effects of BFRs on lung function, emphasizing the importance of further investigating the potential health consequences of these compounds. Further large-scale longitudinal studies are needed to investigate this relationship in the future.

Studies on the degradation pattern of wheat malt endo-1,4-ß-xylanase on wheat-derived arabinoxylans.

BACKGROUND: Wheat malt endo-1,4-ß-xylanase is a key enzyme for arabinoxylan degradation, but its wheat-derived arabinoxylan degradation pattern is unclear. RESULTS: Water-extractable arabinoxylan (WEAX) of 300-750 kDa and 30-100 kDa were the two components with the highest degradation efficiency of wheat malt endo-1,4-ß-xylanase, followed by > 1000 kDa WEAX, but 100-300 kDa WEAX showed the lowest degradation efficiency. The main enzymatic products were the 5-30 kDa WEAX, which accounted for 57.57%, 68.15%, and 52.28% of WAXH, WAXM, and WAXL products, respectively. The enzymatic efficiency of wheat malt endo-1,4-ß-xylanase was relatively high, and the continuity of enzymatic efficiency was good, especially since the enzymatic reaction was the most intense in 1-3 h. WEAX of > 300 kDa was highly significant and positively correlated with viscosity. In comparison, WEAX of < 30 kDa was highly significant and negatively correlated with viscosity. As the enzymatic degradation proceeded, there were fewer and fewer macromolecular components but more and more small molecule components, and the system viscosity became smaller and smaller. CONCLUSION: In this study, it was found that wheat malt endo-1,4-ß-xylanase degraded preferentially 300-750 kDa and 30-100 kDa WEAX, not in the order of substrate size in a sequential enzymatic degradation. Wheat malt endo-1,4-ß-xylanase was most efficient within 3 h, primarily generating < 30 kDa WEAX ultimately. The main products were highly significantly negatively correlated with the system viscosity, so that the system viscosity gradually decreased as the enzymatic hydrolysis proceeded. © 2024 Society of Chemical Industry.

Extended Dynamic Mode Decomposition with Invertible Dictionary Learning.

The Koopman operator has received attention for providing a potentially global linearization representation of the nonlinear dynamical system. To estimate or control the original system, the invertibility problem is introduced into the data-driven modeling, i.e., the observables are required to be reconstructed the original system's states. Existing methods cannot solve this problem perfectly. Only linear or nonlinear but lossy reconstruction can be achieved. This paper proposed a novel data-driven modeling approach, denoted as the Extended Dynamic Mode Decomposition with Invertible Dictionary Learning (EDMD-IDL) to address this issue, which can be interpreted as a further extension of the classical Extended Dynamic Mode Decomposition (EDMD). The Invertible Neural Network (INN) is introduced in the proposed method, where its inverse process provides the explicit inverse on the dictionary functions, thus allowing the nonlinear and lossless reconstruction. An iterative algorithm is designed to solve the extended optimization problem defined by the Koopman operator and INN by combining the optimization algorithm based on the gradient descent and the classical EDMD method, making the method successfully obtain the finite-dimensional approximation of the Koopman operator. The method is tested on various canonical nonlinear dynamical systems and is shown that the predictions obtained in a linear fashion and the ground truth match well over the long-term, where only the initial status is provided. Comparison experiments highlight the superiority of the proposed method over the other EDMD-based methods. Notably, a typical example in fluid dynamics, cylinder wake, illustrates the potential of the method to be further extended to the high-dimensional system with tens of thousands of states. By combining the Proper Orthogonal Decomposition technique, nontrivial Kármán vortex sheet phenomenon is perfectly reconstructed. Our proposed method provides a new paradigm for solving the finite-dimensional approximation of the Koopman operator and applying it to data-driven modeling.

Caffeinated beverages intake and risk of deep vein thrombosis: A Mendelian randomization study.

This study aimed to explore the potential link between coffee and tea consumption and the risk of deep vein thrombosis (DVT) through Mendelian randomization (MR) analysis. Employing the MR, we identified 33 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for coffee intake and 38 SNPs for tea intake. The investigation employed the inverse-variance weighted (IVW) method to evaluate the causal impact of beverage consumption on DVT risk. Additionally, MR-Egger and MR-PRESSO tests were conducted to assess pleiotropy, while Cochran's Q test gauged heterogeneity. Robustness analysis was performed through a leave-one-out approach. The MR analysis uncovered a significant association between coffee intake and an increased risk of DVT (odds ratio [OR] 1.008, 95% confidence interval [CI] = 1.001-1.015, P = 0.025). Conversely, no substantial causal effect of tea consumption on DVT was observed (OR 1.001, 95% CI = 0.995-1.007, P = 0.735). Importantly, no significant levels of heterogeneity, pleiotropy, or bias were detected in the instrumental variables used. In summary, our findings suggest a modestly heightened risk of DVT associated with coffee intake, while tea consumption did not exhibit a significant impact on DVT risk.

Association between lactate-to-albumin ratio and 28-days all-cause mortality in patients with sepsis-associated liver injury: a retrospective cohort study.

BACKGROUND: The mortality rate of sepsis-associated liver injury (SALI) is relatively high, but there is currently no authoritative prognostic criterion for the outcome of SALI. Meanwhile, lactate-to-albumin ratio (LAR) has been confirmed to be associated with mortality rates in conditions such as sepsis, heart failure, and respiratory failure. However, there is a scarcity of research reporting on the association between LAR and SALI. This study aimed to elucidate the association between LAR and the 28-day mortality rate of SALI. METHODS: In this retrospective cohort study, data were obtained from the Medical Information Mart for Intensive Care IV (v2.2). Adult patients with SALI were admitted to the intensive care unit in this study. The LAR level at admission was included, and the primary aim was to assess the relationship between the LAR and 28-day all-cause mortality. RESULTS: A total of 341 patients with SALI (SALI) were screened. They were divided into a survival group (241) and a non-survival group (100), and the 28-day mortality rate was 29.3%. Multivariable Cox regression analysis revealed that for every 1-unit increase in LAR, the 28-day mortality risk for SALI patients increased by 21%, with an HR of 1.21 (95% CI 1.11 ~ 1.31, p < 0.001). CONCLUSIONS: This study indicates that in patients with SALI, a higher LAR is associated with an increased risk of all-cause mortality within 28 days of admission. This suggests that LAR may serve as an independent risk factor for adverse outcomes in SALI patients.

Recent progress in SEI engineering for boosting Li metal anodes.

Lithium metal anodes (LMAs) are ideal anode candidates for achieving next-generation high-energy-density battery systems due to their high theoretical capacity (3680 mA h g-1) and low working potential (-3.04 V versus the standard hydrogen electrode). However, the non-ideal solid electrolyte interface (SEI) derived from electrolyte/electrode interfacial reactions plays a vital role in the lithium deposition/stripping process and battery cycling performance. The composition and morphology of a SEI, which is sensitive to the outside environment, make it difficult to characterize and understand. With the development of characterization techniques, the mechanism, composition, and structure of a SEI can be better understood. In this review, the mechanism formation, the structure model evolution, and the composition of a SEI are briefly presented. Moreover, the development of in situ characterization techniques in recent years is introduced to better understand a SEI followed by the properties of the SEI, which are beneficial to the battery performance. Furthermore, recent optimization strategies of the SEI including the improvement of intrinsic SEIs and construction of artificial SEIs are summarized. Finally, the current challenges and future perspectives of SEI research are summarized.

Aspergillus niger fermentation residues application to produce biochar for the anode of lithium-ion batteries.

Aspergillus niger is widely applied in the fermentation industry, but produce abundant mycelium residues every year. As a kind of solid waste, mycelium residues seriously affect the environment. How to manage and utilize this solid waste is a problem for the fermentation industry. It was reported that many kinds of biomass could be utilized to produce carbon materials, which would be further used to produce lithium-ion rechargeable batteries (LIBs). Here, porous biochar was prepared from A. niger mycelial residues and further used as an anode for LIBs. Since the A. niger mycelium contains abundant nitrogen (5.29%) from its chitosan-dominated cell wall, and silicon (9.63%) from perlite filter aid, respectively, the biochar presented an excellent cycle stability and rate performance when applied as the anode of LIBs. The conclusion of this research shows the wide application prospect of fungal fermentation residues as carbon precursors in energy storage devices. Meanwhile, this investigation provides an alternative management method for A. niger mycelium residues, with which the mycelium residues could be effectively recycled to avoid resource waste and environmental pollution.

Hepatotoxicity evaluation and possible mechanisms of decabrominated diphenyl ethers (BDE-209) in broilers: Oxidative stress, inflammatory, and transcriptomics.

Decabrominated diphenyl ether (BDE-209), a persistent organic pollutant, is linked to a great number of health problems, the most severe of which impact the liver due to its role in the elimination and degradation of exogenous harmful substances. Though the hepatotoxicity of BDE-209 has been observed, its underlying mechanism is yet unknown. The purpose of this study is to thoroughly investigate the hepatotoxicity of BDE-209 and its molecular processes in broilers by subjecting 120 male broilers to varied concentrations of BDE-209 for 42 days. We observed that the bioaccumulation of BDE-209 in the liver in a dose-dependent manner, and that BDE-209 exposure can raise the concentrations of ALT, AST, and GGT, accompanied by hepatocyte fatty degeneration and inflammatory foci. In the hepatic homogenates, oxidative stress was evidenced by elevated levels of MDA and ROS and decreased activies of SOD and CAT. Additionally, pro-inflammatory cytokines including IL-1, IL-1ß, TNF-α, IL-8 levels were increased, whereas anti-inflammatory cytokine IL-4 level was declined. Furthermore, RNA sequencing revealed that genes involved in inflammation were considerably dysregulated, and real-time PCR verified the expressed alterations of numerous genes related to the MAPK and WNT signaling pathways. The protein concentrations of NF-κB, ß-catenin, and WNT5A, and the phosphorylation levels of JNK and ERK were all dramatically enhanced. The current study indicates that BDE-209 exposure can cause hepatotoxicity in broilers via bioaccumulation and oxidative stress, which then activates the MAPK and WNT signaling pathways, subsequently generating inflammation and hepatic injury.

Vitamin D and idiopathic pulmonary fibrosis: a two-sample mendelian randomization study.

BACKGROUND: A prospective study of multiple small samples found that idiopathic pulmonary fibrosis (IPF) is often accompanied by a deficiency in Vitamin D levels. However, the causal relationship between the two remains to be determined. Therefore, our study aims to investigate the causal effect of serum 1,25-hydroxyvitamin D (25(OH)D) on the risk of IPF through a two-sample Mendelian randomization (MR) analysis. METHODS: Through data analysis from two European ancestry-based genome-wide association studies (GWAS), including 401,460 individuals for 25(OH)D levels and 1028 individuals for IPF, we primarily employed inverse-variance weighted (IVW) to assess the causal effect of 25(OH)D levels on IPF risk. MR-Egger regression test was used to determine pleiotropy, and Cochran's Q test was conducted for heterogeneity testing. Leave-one-out analysis was conducted to examine the robustness of the results. RESULTS: 158 SNPs related to serum 25(OH)D were used as instrumental variables (IVs). The MR analyses revealed no evidence supporting a causal association between the level of circulating 25(OH)D and the risk of IPF. The IVW method [OR 0.891, 95%CI (0.523-1.518), P = 0.670]; There was no significant level of heterogeneity, pleiotropy and bias in IVs. Cochran's Q test for heterogeneity (MR Egger P = 0.081; IVW P = 0.089); MR-Egger regression for pleiotropy (P = 0.774). CONCLUSIONS: This MR Study suggests that genetically predicted circulating vitamin D concentrations in the general population are not causally related to IPF.

Possible sarcopenia and risk of new-onset type 2 diabetes mellitus in older adults in China: a 7-year longitudinal cohort study.

BACKGROUND: Previous studies have shown that type 2 diabetes mellitus (T2DM) can cause sarcopenia; however, these conditions may have a bidirectional association. This study aimed to explore the longitudinal association between possible sarcopenia and new-onset T2DM. METHODS: We conducted a population-based cohort study using nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS). This study included participants aged ≥ 60 years who were free of diabetes during the baseline survey of CHARLS (2011 to 2012) and were followed up until 2018. Possible sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Cox proportional hazards regression models were used to evaluate the effect of possible sarcopenia on new-onset T2DM. RESULTS: In total, 3,707 individuals were enrolled in this study, with a median age of 66 years; the prevalence of possible sarcopenia was 45.1%. During the 7-year follow-up, 575 cases (15.5%) of incident diabetes were identified. Participants with possible sarcopenia were more likely to have new-onset T2DM than those without possible sarcopenia (hazard ratio: 1.27, 95% confidence interval: 1.07-1.50; p = 0.006). In subgroup analysis, we found a significant association between possible sarcopenia and T2DM in individuals aged < 75 years or with a BMI < 24 kg/m². However, this association was not significant in individuals aged ≥ 75 years or with a BMI ≥ 24 kg/m². CONCLUSIONS: Possible sarcopenia is associated with an increased risk of new-onset T2DM in older adults, especially in individuals who are not overweight and aged 75 years or younger.

Domesticating aquatic plants in hydroponic systems to demonstrate and advance phytoremediation of the artificial sweetener acesulfame.

Artificial sweeteners (ASs) are ubiquitously detected in the global water system, among which acesulfame (ACE) is an emerging contaminant for its chemical and biological stability and unsatisfying removal by conventional or advanced treatment technologies. Phytoremediation is an effective and sustainable in-situ remediation technology that this study is the first to explore ACE removal by aquatic plants. The emergent plants, Scirpus Validus (S. validus), Phyllostachys heteroclada Oliver (P. heteroclada) and Acorus tatarinowii (A. tatarinowii) showed superior removal capability than eleven floating plants, and demonstrated high phytoremediation efficiencies (PEs) of up to 75 % after 28 d domestication. ACE removal by the three emergent plants increased during domestication, as the PEs after 28 d domestication were 5.6-6.5 times of 7 d domestication. Notably, the half-life of ACE was decreased from 20.0 to 33.1 d to 1.1-3.4 d in the plant-hydroponic system, compared with 481.0-1152.4 d in control water without plants. Moreover, A. tatarinowii demonstrated the highest removal capacity for ACE with 0.37 mg/g fresh biomass weight (FW), higher than S. validus (0.27 mg/g FW) and P. heteroclada (0.20 mg/g FW). It is worth noting that a mass balance analysis demonstrated that plant transpiration and plant uptake account for about 6.72 %-18.54 % and 9.69 %-21.67 % ACE removal, while hydrolysis only accounted for about 4 % and photolysis was negligible. The rest ACE may be used as a carbon source by endophytic bacteria and root microorganisms of plants. In addition, increased temperature, pH, and illumination intensity had a significant effect on phytoremediation. In the selected experimental range, the increase of temperature from 15 °C to 35 °C, illumination intensity from 1500 lx to 6000 lx, and pH from 5 to 9 generally accelerated the PEs of ACE during the domestication process. Though the mechanism still requires further investigation, the results provide scientific and feasible data for removal of ACE from water by diverse plants for the first time, and also revealed insights for in-situ treatment of ACE.

Ion modulation engineering toward stable lithium metal anodes.

Homogeneous ion transport during Li+ plating/stripping plays a significant role in the stability of Li metal anodes (LMAs) and the electrochemical performance of Li metal batteries (LMBs). Controlled ion transport with uniform Li+ distribution is expected to suppress notorious Li dendrite growth while stabilizing the susceptible solid electrolyte interfacial (SEI) film and optimizing the electrochemical stability. Here, we are committed to rendering a comprehensive study of Li+ transport during the Li plating/stripping process related to the interactions between the Li dendrites and SEI film. Moreover, rational ion modulation strategies based on functional separators, artificial SEI films, solid-state electrolytes and structured anodes are introduced to homogenize Li+ flux and stabilize the lithium metal surface. Finally, the current issues and potential opportunities for ion transport regulation to boost the high energy density of LMBs are described.

Functional Separator Enabled by Covalent Organic Frameworks for High-Performance Li Metal Batteries.

Uncontrolled ion transport and susceptible SEI films are the key factors that induce lithium dendrite growth, which hinders the development of lithium metal batteries (LMBs). Herein, a TpPa-2SO3 H covalent organic framework (COF) nanosheet adhered cellulose nanofibers (CNF) on the polypropylene separator (COF@PP) is successfully designed as a battery separator to respond to the aforementioned issues. The COF@PP displays dual-functional characteristics with the aligned nanochannels and abundant functional groups of COFs, which can simultaneously modulate ion transport and SEI film components to build robust lithium metal anodes. The Li//COF@PP//Li symmetric cell exhibits stable cycling over 800 h with low ion diffusion activation energy and fast lithium ion transport kinetics, which effectively suppresses the dendrite growth and improves the stability of Li+ plating/stripping. Moreover, The LiFePO4//Li cells with COF@PP separator deliver a high discharge capacity of 109.6 mAh g-1 even at a high current density of 3 C. And it exhibits excellent cycle stability and high capacity retention due to the robust LiF-rich SEI film induced by COFs. This COFs-based dual-functional separator promotes the practical application of lithium metal batteries.

Induced bimetallic sulfide growth with reduced graphene oxide for high-performance sodium storage.

Metal sulfide has been considered an ideal sodium-ion battery (SIB) anode material based on its high theoretical capacity. Nevertheless, the inevitable volume expansion during charge-discharge processes can lead to unsatisfying electrochemical properties, which limits its further large-scale application. In this contribution, laminated reduced graphene oxide (rGO) successfully induced the growth of SnCoS4 particles and self-assembled into a nanosheet-structured SnCoS4@rGO composite through a facile solvothermal procedure. The optimized material can provide abundant active sites and facilitate Na+ ion diffusion due to the synergistic interaction between bimetallic sulfides and rGO. As the anode of SIBs, this material maintains a high capacity of 696.05 mAh g-1 at 100 mA g-1 after 100 cycles and a high-rate capability of 427.98 mAh g-1 even at a high current density of 10 A g-1. Our rational design offers valuable inspiration for high-performance SIB anode materials.

Degradation of soybean meal proteins by wheat malt endopeptidase and the antioxidant capacity of the enzymolytic products.

This study investigated the hydrolysis effect of the endopeptidase from wheat malt on the soybean meal proteins. The results indicated that the endopeptidase broke the peptide bonds of soybean meal proteins and converted the alcohol- and alkali-soluble proteins into water-soluble and salt-soluble proteins. In addition, wheat malt endopeptidase did not break the disulfide bonds between proteins but affected the conformation of disulfide bonds between substrate protein molecules, which were changed from the gauche-gauche-trans (g-g-t) vibrational mode to the trans-gauche-trans (t-g-t) vibrational mode. Wheat malt endopeptidase exhibited the highest enzymatic activity at 2 h of enzymatic digestion, demonstrating the fastest hydrolytic rate of soybean meal proteins. Compared with the samples before enzymatic hydrolysis, the total alcohol- and alkali-soluble proteins were decreased by 11.89% but the water- and salt-soluble proteins were increased by 11.99%, indicating the hydrolytic effect of endopeptidase. The corresponding water-soluble proteins had molecular weights of 66.4-97.2, 29-44.3, and 20.1 kDa, while the salt-soluble proteins had molecular weights of 44.3-66.4, 29-44.3, and 20.1 kDa, respectively. The degree of enzymatic hydrolysis of soybean meal reached the maximum at 8 h. The newly created proteins exhibited significantly antioxidant properties, which were inversely related to the molecular weight. Proteins with molecular weight <3 kDa had the highest antioxidant performance with an antioxidant capacity of 1.72 ± 0.03 mM, hydroxyl radical scavenging rate of 98.04%, and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging capacity of 0.44 ± 0.04 mM.

Cuboid-like phosphorus-doped metal-organic framework-derived CoSe2 on carbon cloth as an advanced bifunctional oxygen electrocatalyst for rechargeable zinc-air batteries.

Zinc-air batteries (ZABs) are regarded as attractive devices for electrochemical energy storage and conversion due to their outstanding electrochemical performance, low price, and high safety. However, it remains a challenge to design a stable and efficient bifunctional oxygen catalyst that can accelerate the reaction kinetics and improve the performance of ZABs. Herein, a phosphorus-doped transition metal selenide/carbon composite catalyst derived from metal-organic frameworks (P-CoSe2/C@CC) is constructed by a self-supporting carbon cloth structure through a simple solvothermal process with subsequent selenization and phosphatization. The P-CoSe2/C@CC exhibits a low overpotential of 303.1 mV at 10 mA cm-2 toward the oxygen evolution reaction and an obvious reduction peak for the oxygen reduction reaction. The abovementioned electrochemical performances for the P-CoSe2/C@CC are attributed to the specific architecture, the super-hydrophilic surface, and the P-doping effect. Remarkably, the homemade zinc-air battery based on our P-CoSe2/C@CC catalyst shows an expected peak power density of 124.4 mW cm-2 along with excellent cycling stability, confirming its great potential application in ZABs for advanced bifunctional electrocatalysis.

Polyvinylpyrrolidone-derived nitrogen-doped carbon-coated MoS2 composites for enhanced sodium storage performance.

Two-dimensional transition metal dichalcogenides, which display considerable theoretical capacity and large layer spacing, have been regarded as promising candidates as anode materials for sodium-ion batteries (SIBs). However, their low conductivity and large volume change during charge-discharge cycles leads to performance degradation. Herein, polyvinylpyrrolidone (PVP) is used as a soft template to synthesize PVP-derived nitrogen-doped carbon-coated MoS2 composites (MoS2/NC) by a simple hydrothermal method followed by high-temperature treatment. The as-prepared composite exhibits a flowerball-like morphology and a diameter of approximately 250 nm. The optimized MoS2/NC has the most uniform particle size and provides the best performance, with a stable capacity of 504.9 mAh g-1 after 120 cycles at a current density of 100 mA g-1. It has excellent rate performance, which can reach 524.6, 481.9, 447.7, 412.5, and 370.9 mAh g-1 at current densities of 0.1, 0.2, 0.5, 1 and 2 A g-1, respectively. The small particle size and the addition of carbonaceous materials play an important role in their excellent electrochemical properties. This study opens up a simple and effective way to synthesize high-performance two-dimensional MoS2 composite anodes for SIBs.

The effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer.

The present work explored the effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer. Results illustrated that the addition of wheat malt can significantly improve the soluble protein of wort and the final beer, and it can provide more > 2.2 kDa protein in final beer, which is mainly derived from the raw wheat malt, but also including some protein produced in the fermentation process, such as some protein between 29 and 66.4 kDa. Though the content of > 15 kDa protein was relatively lower than the protein whose molecular weight was < 15 kDa, but it had important effects on total nitrogen, total water-soluble protein, free amino nitrogen, chromaticity, and viscosity of final beer. The addition of wheat malt significantly improved the concentration of 2.2-15 and > 15 kDa protein, but higher percentage of addition ratio can decrease the foam stability of the beer. PRACTICAL APPLICATION: This findings can reasonably control the protein content and types of wheat beer, improve the quality of wheat beer, solve the key technological problems, and expand and popularize the application of wheat in beer industry.

Association between serum sodium and in-hospital mortality among critically ill patients with spontaneous subarachnoid hemorrhage.

Objective: The aim of this study was to retrospectively explore the relationship between serum sodium and in-hospital mortality and related factors in critically ill patients with spontaneous subarachnoid hemorrhage (SAH). Methods: Data were collected from the Medical Information Mart for Intensive Care IV database. Restricted cubic splines were used to explore the relationship between serum sodium and in-hospital mortality. Receiver operating characteristic analysis was used to calculate the optimal cutoff value of sodium fluctuation, and decision curve analysis was plotted to show the net benefit of different models containing serum sodium. Results: A total of 295 patients with spontaneous SAH were included in the retrospective analysis. The level of sodium on ICU admission and minimum sodium in the ICU had a statistically significant non-linear relationship with in-hospital mortality (non-linear P-value < 0.05, total P-value < 0.001). Serum sodium on ICU admission, minimum serum sodium during ICU, and sodium fluctuation were independently associated with in-hospital mortality with odds ratios being 1.23 (95% confidence interval (CI): 1.04-1.45, P = 0.013), 1.35 (95% CI: 1.18-1.55, P < 0.001), and 1.07 (95% CI: 1.00-1.14, P = 0.047), respectively. The optimal cutoff point was 8.5 mmol/L to identify in-hospital death of patients with spontaneous SAH with sodium fluctuation, with an AUC of 0.659 (95% CI 0.573-0.744). Conclusion: Among patients with spontaneous SAH, we found a J-shaped association between serum sodium on ICU admission and minimum sodium values during ICU with in-hospital mortality. Sodium fluctuation above 8.5 mmol/L was independently associated with in-hospital mortality. These results require being tested in prospective trials.