ObjectiveDonkey hide is the sole legally designated raw material for the preparation of the traditional Chinese medicine Ejiao. The quality stability of donkey hide during preservation directly determines the efficacy and safety of Ejiao. This study focuses on the dynamic succession of microbial communities during the preservation of donkey hides from different origins, aiming to clarify the correlation between microbial biodiversity difference and the degradation profiles of hide collagen and critical biochemical components, thereby providing a theoretical foundation for developing targeted preservation strategies based on microbial regulation. MethodsDonkey hides originating from four different regions were subjected to an accelerated microbial aging assay to simulate the spoilage process. The microbial community succession was analyzed using high-throughput sequencing. Microstructure changes and pore structure characteristics were assessed by scanning electron microscopy and mercury intrusion porosimetry, respectively. Additionally, the content of major components, including lipids, proteins, and sugars were determined by biochemical methods. ResultsAfter 96 h of aging, the collagen fiber structure in Africa donkey hides (ADH) exhibited significant degradation and collapse, followed by Xinjiang donkey hides (XDH). Instead, the microstructure of Dong’e black donkey hides (DDH) and Peru donkey hides (PDH) remained relatively intact. The porosities of DDH, XDH, PDH, and ADH increased from 27.9%, 15.7%, 30.3%, and 46.2% to 36.5%, 52.6%, 42.8%, and 57.7%, respectively, during the aging process, which suggested that the originally compact fiber structure was disrupted by microbial aging. Fourier transform infrared spectrometer analysis revealed the amide bands in XDH exhibited relatively weak intensity, and no collagen amide I band was observed in ADH. Meanwhile, the lipid and protein contents decreased in all four types of donkey hides, indicating that these components served as the primary nutrient sources for the growth of microorganism. Notably, the most severe collagen degradation was observed in XDH and ADH. A substantial increase was detected in the total soluble sugar in PDH aging solution and hydroxyproline in the ADH aging solution, respectively. These results indicated that donkey hides exhibit distinct patterns of structural degradation and nutrient utilization. Furthermore, the viable cells number of donkey hides increased sharply after 48 h of aging. Metagenomic analysis revealed that the relative abundance of Euryarchaeota in ADH, PDH and XDH declining from initial 93.19%, 97.73% and 30.08% to 0.79%, 1.43% and 0.02% after 96 h, respectively. Conversely, a significantly increase was observed in the abundance of Bacillota, with a marked increase in ADH, peaking at 92.75%. Additionally, the abundance of Pseudomonadota in PDH increased from 0.10% to 87.84%, suggesting that Bacillota and Pseudomonadota may be key factors exacerbating donkey hide spoilage. Unlike the other three types of donkey hides, the dominant bacterial phylum in DDH shifted from Pseudomonadota to Bacteroidota, characterized by a substantial abundance increase of Bacteroidota from 0.13% to 44.22%. ConclusionRegional variation in origin significantly influence the microbial aging of donkey hides, leading to distinct patterns of structural deterioration and differential nutrient utilization. Therefore, implementing origin-specific preservation strategies, through the precisely controlling environmental factors to suppress harmful phyla such as Bacillota and Pseudomonadota, is crucial for enhancing the storage quality of donkey hides.

Glycogen synthase 1 (GYS1) is the rate-limiting enzyme responsible for glycogen synthesis in skeletal muscle, heart, brain, and other extrahepatic tissues, playing a central role in systemic energy homeostasis. The human GYS1 gene maps to chromosome 19q13.33, comprises 16 exons, and encodes a 737-amino-acid polypeptide that is highly conserved across mammals. GYS1 activity is subject to multilayered and precisely coordinated regulation. At the transcriptional level, the GYS1 promoter contains a hypoxia response element (HRE) that mediates HIF-1α-dependent induction under low-oxygen conditions, as well as a muscle-specific enhancer harboring MEF2 and MyoD binding sites that confers tissue-restricted expression. At the post-translational level, a hierarchical phosphorylation cascade serves as the primary activity switch: glycogen synthase kinase 3β (GSK3β) sequentially phosphorylates four C-terminal serine residues following casein kinase II priming, while protein kinase A (PKA) and AMP-activated protein kinase (AMPK) provide parallel inhibitory inputs at both N- and C-terminal sites. Dephosphorylation and reactivation are mediated by protein phosphatase 1 (PP1) through tissue-specific glycogen-targeting regulatory subunits such as PPP1R3A and PPP1R3B, which anchor PP1 to glycogen particles and direct its activity toward GYS1. The allosteric activator glucose-6-phosphate (G6P) binds at the dimer interface, simultaneously enhancing catalytic efficiency and promoting dephosphorylation susceptibility, thereby establishing a feed-forward activation loop that couples substrate availability to glycogen synthesis. Beyond phosphorylation, GYS1 is regulated by ubiquitination (mediated by the E3 ligase PJA1), acetylation, O-linked β-N-acetylglucosamine (O-GlcNAc) modification, and SUMOylation, which collectively modulate protein stability, subcellular localization, and protein-protein interactions. Epigenetic mechanisms, including CpG island methylation and histone acetylation dynamics, govern chromatin accessibility at the GYS1 locus, while muscle-specific microRNAs such as miR-1 and miR-206 fine-tune GYS1 expression at the post-transcriptional level. Dysregulation of GYS1 has been identified as a central pathogenic driver in a spectrum of human diseases. In inherited glycogen storage disorders—including Lafora disease, adult polyglucosan body disease (APBD), and Pompe disease—loss of upstream regulatory control leads to GYS1 hyperactivation and the accumulation of structurally abnormal or excessive glycogen, resulting in progressive neurodegeneration, myopathy, and multiorgan dysfunction. In type 2 diabetes mellitus (T2DM), impaired insulin signaling through the PI3K-AKT-GSK3β axis maintains GYS1 in a hyperphosphorylated inactive state in skeletal muscle, compromising postprandial glucose disposal and exacerbating hyperglycemia. In oncology, GYS1 exhibits context-dependent roles across multiple cancer types. In hepatocellular carcinoma, FMO2⁺ cancer-associated fibroblasts stabilize GYS1 by competitively inhibiting PJA1-mediated ubiquitination, and stabilized GYS1 subsequently activates NF‑κB/CCL19 signaling to promote tertiary lymphoid structure formation and enhance anti-PD-1 immunotherapy responsiveness. In clear cell renal cell carcinoma, GYS1 promotes tumor progression through non-canonical NF‑κB pathway activation via the scaffold protein RPS27A. In triple-negative breast cancer, GYS1 has been identified as a trigger of disulfidptosis and an activator of NF-κB signaling through non-enzymatic facilitation of IκBα degradation. In colorectal cancer, mitochondrial fission deficiency drives AMPK-dependent GYS1 upregulation and glycogen accumulation as a compensatory survival mechanism, while in cervical cancer, GYS1-maintained glycogen reserves fuel the pentose phosphate pathway to generate NADPH for ROS clearance, thereby conferring cisplatin resistance in cancer stem cells. Therapeutic strategies targeting GYS1 have gained substantial momentum across these disease contexts. For glycogen storage disorders, antisense oligonucleotides, small interfering RNAs (e.g., ABX1100), and small-molecule inhibitors (e.g., MZ-101) have demonstrated preclinical and early clinical efficacy in reducing pathological glycogen accumulation. For T2DM, pharmacological activation of GYS1 through GSK3β inhibition or enhancement of PP1-mediated dephosphorylation is being explored to restore insulin-stimulated glycogen synthesis. In cancer, GYS1-directed interventions—including targeted silencing to sensitize tumors to chemotherapy and immune microenvironment modulation to enhance immunotherapy—represent emerging precision oncology approaches. This review provides a comprehensive and integrated account of GYS1 gene structure, tissue-specific distribution, regulatory networks, and pathogenic roles in metabolic disorders and malignancies, with the aim of establishing a theoretical framework for the development of GYS1-targeted precision therapies.

Abstract To clarify the service targets, service contents, and safeguard mechanisms of the basic public service program for student vision health management, the study grounded in the current status of child and adolescent myopia prevention and control in China and integrated with the practical experience and innovative practices of Wuhan National Demonstration Area for Student Vision Health Management, takes education as the main thread and schools as the base, consolidating resources from multiple stakeholders including education administrative departments, schools, families, and professional technical service institutions. Centering on four core components—vision health education, monitoring and record keeping, risk prevention and control, and dynamic management, the study constructs a multi tiered basic public service system for vision health management of primary and secondary school students. It further proposes the use of an intelligent management platform and a "three tier color coded early warning" mechanism (red, yellow, blue) to prevent and control student myopia at the source, providing schools with replicable and operable implementation pathways to enhance the level of student vision health management.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Objective:To investigate the co-occurrence patterns of psychosocial and behavioral problems among children and to identify associated influencing factors.Methods:A multicenter cross-sectional survey was conducted in 2023. A cluster random sample of 19 176 children aged 6-16 years was recruited from middle-income areas across 10 provincial capitals and municipalities in China. Psychological and behavioral problems, including anxiety, compulsive behavior, social withdrawal, depression, somatic complaints, social problems, schizoid, delinquent behaviors, hyperactivity, sexual issues, and aggression, were assessed using the Achenbach Child Behavior Checklist parent version. Co-occurrence was defined as ≥2 concurrent problems. Children were divided into 4 groups by gender and age: boys aged 6-11 years, girls aged 6-11 years, boys aged 12-16 years, and girls aged 12-16 years. Those children who had psychosocial and behavioral problems were further categorized into the single-problem group, and the co-occurrence group based on assessment results. High-frequency co-occurrence phenotypes of children′s psychosocial and behavioral problems were identified. Demographic factors, such as parental employment, education, as well as psychosocial factors like parent-child relationship, screen time and outdoor activity, were investigated. χ 2 test was used to analyze differences between groups. Multivariate Logistic regression modeling was conducted to identify potential factors. Results:Among 14 711 children (7 501 boys, 7 210 girls) who provided effective questionnaires, the detection rates of single problem in the boys aged 6-11 years, girls aged 6-11 years, boys aged 12-16 years, and girls aged 12-16 years groups were 4.9% (171/3 461), 6.2% (193/3 120), 3.9% (158/4 040), and 5.1% (208/4 090), respectively; the detection rates of co-occurrence were 7.6% (262/3 461), 7.7% (241/3 120), 4.9% (199/4 040), and 5.7% (234/4 090), respectively. The overall detection rates of co-occurrence was higher than that of single problem ( χ2=25.47, P<0.001). Among children with co-occurrence, there were varied manifestations: in the boys aged 6-11 years group, the detection rates of social withdrawal (69.8% (183/262)), schizoid-like behavior (68.3% (179/262)), and compulsive behavior (67.6% (177/262)) were relatively high; in the girls aged 6-11 years group, the detection rates of schizoid-compulsive behavior (69.3% (167/241)), delinquent behavior (65.6% (158/241)), and hyperactivity (58.9% (142/241)) were relatively high; in the boys aged 12-16 years group, the detection rates of hyperactivity (78.9% (157/199)), compulsive behavior (67.3% (134/199)), and immature behavior (57.3% (114/199)) were relatively high; in the girls aged 12-16 years group, the detection rates of schizoid-like behavior (89.7% (210/234)), immature behavior (59.0% (138/234)), and cruelty (57.7% (135/234)) were relatively high. Maternal bachelor′s degree or higher ( OR=0.78, 95% CI 0.61-0.99, P=0.038) served as co-occurrence protective factors, whereas having 1 or more siblings, increased parent-child conflict and decreased parent-child interaction time ( OR=1.24, 1.41, 1.36; 95% CI 1.02-1.52, 1.15-1.73, 1.02-1.82, all P<0.05) were co-occurrence risk factors. Conclusions:Children exhibit strong co-occurrence tendencies in psychosocial and behavioral problems. Compulsive and schizoid traits are the predominant co-occurring phenotypes for childhood and girls respectively. ?Familial environment plays a critical role, necessitating ?multidimensional clinical assessments and ?family-centered interventions.

Objective:To investigate the clinical demand for subcutaneous immunotherapy (SCIT) with pet allergens and explore the sensitization characteristics of patients undergoing pet SCIT.Methods:A cross-sectional retrospective analysis was conducted on patients diagnosed with pet allergies and treated with pet allergen SCIT in our outpatient clinic from January 2019 to December 2023. Patients were categorized into three groups based on the type of SCIT received: single-cat SCIT group, single-dog SCIT group, and combined cat-dog SCIT group.Results:A total of 931 patients were included, the age range was 5-65 years (median age of 30 years), with 283 male and 648 female. Among them, 67.7%( n=630) received single-cat SCIT, 10.9% ( n=102)received single-dog SCIT, and 21.4% ( n=199) received combined cat-dog SCIT. The number of patients receiving pet allergen SCIT increased annually. Patients in the single-dog SCIT group were significantly older than those in the other two groups ( H=41.329, P<0.001) and had a lower prevalence of allergic rhinitis (91.2% vs. 96.5% and 98.5%; χ2=10.400, P=0.006). In the combined cat-dog SCIT group, the allergy rate to mold allergens was significantly higher than in the single-cat SCIT group (12.6% vs. 4.9%, χ2=13.965, P=0.001). In the single-dog SCIT group, the allergy rate to spring pollen allergens was significantly higher than in the other two groups ( χ2=15.731, P<0.001), and the allergy rate to autumn pollen allergens was significantly higher than in the single-cat SCIT group ( χ2=13.459, P=0.001). There was no significant difference in the dust mite allergy rate among the three groups( χ2=4.117, P=0.129). In the single-dog SCIT group, patients with asthma were significantly older than those without asthma (41.2 vs. 35.2 years old, t=-2.073, P=0.041). In both the single-cat and single-dog SCIT groups, the proportion of allergic rhinitis in the asthma group(91.2%,78.3%) was significantly lower than that in the non-asthma group(97.4%,94.9%) ( χ2=8.863,6.158; P=0.008,0.026). In the single-cat SCIT group, non-asthmatic patients were significantly more likely to receive SCIT combined with spring pollen allergens compared to asthmatic patients (23.9% vs. 11.0%, χ2=7.586, P=0.006). Conclusions:The demand for pet allergen SCIT has steadily increased over the years, with a predominance of female patients. Sensitization profiles varied among patients receiving SCIT for different pet allergens. This study comprehensively elucidates the clinical demand and sensitization characteristics of patients undergoing pet allergen SCIT, providing valuable reference data for clinical diagnosis and treatment.

Objective To investigate the role of poly(rC)-binding protein 1(PCBP1)in cadmium(Cd)-induced ferroptosis in mouse neuroblastoma Neuro-2a(N2A)cells.Methods N2A cells were exposed to a concentration gradient of CdCl?(0,1,2,4 μmol/L)for 72 h.Cell viability was assessed by trypan blue staining.Western blotting was employed to detect the expression of ferroptosis-related proteins(GPX4,HMOX1,ACSL4)and PCBP1.Intracellular Fe2? level and lipid peroxidation were detected using FerroOrange and BODIPY581/591 C11 probes,respectively.Ferrostatin-1(Fer-1),a ferroptosis inhibitor,was applied to confirm the critical role of ferroptosis in Cd-induced cytotoxicity.Molecular docking was performed to elucidate the interaction between PCBP1 and ferritin,as well as the binding sites of Cd2?.PCBP1 overexpression plasmid was further constructed for functional validation.Results Cd exposure suppressed cell viability in N2A cells in a dose-dependent manner(P<0.01),significantly down-regulated GPX4 expression(P<0.05),up-regulated HMOX1 expression(P<0.01),and induced Fe2? overload and lipid peroxidation(P<0.01).Molecular docking revealed that Cd2? directly bound to the KH2 domain of PCBP1 and then co-localized on the outer surface of ferritin heavy chain.Overexpression of PCBP1 markedly reversed Cd-induced Fe2? accumulation,GPX4 down-regulation,lipid peroxidation,and cell death.Conclusion Cd exposure disrupts PCBP1-mediated iron homeostasis via transcriptional suppression and competitive displacement of metal ions,and then synergistically drives Fe2? overload-triggered ferroptosis cascades,ultimately leading to neurotoxicity.Targeting PCBP1-mediated iron homeostasis can effectively mitigate Cd-induced neurotoxicity,and may serve as a novel therapeutic strategy.

In this study,a sensitive lateral flow immunoassay(LFIA)platform based on carbon dots-mesoporous silica nanocomposite(CD-MSNs)fluorescent probes was constructed for high-performance detection of inflammatory marker interleukin-6(IL-6).Green fluorescent carbon dots(CDs)were prepared by hydrothermal method with 3,9-perylenic acid and 3-aminopropyltriethoxysilane(APTES)as raw materials,and highly fluorescent CD-MSNs composites were then constructed by encapsulating the prepared CDs in mesoporous silica nanoparticles(MSNs).Fluorescent probes were prepared by covalent coupling of CD-MSNs with IL-6 antibody.Fluorescent immunochromatographic test strips were constructed by spraying IL-6 capture antibody and goat anti-mouse IgG on nitrocellulose membrane as detection line(T-line)and quality control line(C-line),respectively.The fluorescence immunoassay analyzer was used to quantitatively detect the fluorescence intensity of T-line,and the experimental results showed that the LFIA platform based on this probe had a good linear relationship in IL-6 concentration range of 102-106 pg/mL,and the detection limit was 64 pg/mL,which was two orders of magnitude more sensitive than that of the traditional colloidal gold test strips.This method effectively solved the issue of insufficient sensitivity of traditional LFIA technique,and provided a rapid and highly sensitive detection method for early diagnosis of inflammatory diseases.

Microalgae can achieve sustainable CO2 fixation and biomass conversion,making them a green path for carbon capture and conversion.Monitoring extracellular carbonic anhydrase(CA)activity in microalgae is crucial for regulating carbon conversion efficiency.In this study,double-stranded DNA was designed as a capture probe to bind H+,which was produced by CA-catalyzed CO2 hydration.This interaction induced conformational changes in the DNA probe,enhancing fluorescence signals and thereby establishing a recognition and signal transduction mechanism for CA catalytic product.This approach enabled a novel method for measuring CA activity.The response of probe to H+was investigated using ultraviolet visible(UV-Vis)spectroscopy,circular dichroism sepctroscopy,and fluorescence spectroscopy.The experimental results indicated that the fluorescence intensity of the probe increased progressively with rising H+concentration.Using this probe,CA activity detection could be completed within 29 min,with a detection range of 0.35-17500 U/mL and a detection limit of 0.15 U/mL.Compared to traditional methods,this approach offered a lower detection limit and was suitable for analyzing and detecting extracellular CA activity in actual algal samples.