1.Mechanisms of Mahuang Lianqiao Chixiaodoutang in Improving Obesity-type Polycystic Ovary Syndrome in Rats Based on PI3K/Akt Signaling Pathway
Shiwei HU ; Biran ZHU ; Jinrong ZHANG ; Luyao RUAN ; Ji KUANG ; Jianghuan HUA ; Zhe LIU ; Yanyue YAO ; Ji WANG ; Min ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):21-31
ObjectiveTo investigate the mechanisms by which Mahuang Lianqiao Chixiaodoutang (MLC) improves obesity-type polycystic ovary syndrome (PCOS) through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. MethodsThirty-six female Sprague-Dawley (SD) rats were randomly divided into a blank control group (Con) and an obesity-type PCOS model preparation group. The model was induced by gavage with letrozole (1 mg·kg-1) combined with a high-fat diet (HFD). After model establishment, the obesity-type PCOS model preparation group was further divided into the model group (Mod, normal saline), metformin group (Met, 0.3 g·kg-1), low-dose MLC group (MLC-L, 4.3 g·kg-1), medium-dose MLC group (MLC-M, 8.6 g·kg-1), and high-dose MLC group (MLC-H, 17.2 g·kg-1). Active components of MLC and targets of obesity-type PCOS were screened from databases, a protein-protein interaction (PPI) network was constructed, and gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed. The gut microbiota structure was analyzed based on 16S rRNA sequencing and correlated with network pharmacology pathways. Body weight and estrous cycle were dynamically monitored. Ovarian morphology was observed by hematoxylin-eosin (HE) staining. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Enzyme-linked immunosorbent assay (ELISA) was used to detect levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), testosterone (T), and estradiol (E2). Western blot was used to detect the protein expression levels of phosphorylated PI3K/PI3K (p-PI3K/PI3K), phosphorylated Akt/Akt (p-Akt/Akt), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax). ResultsNetwork pharmacology screening identified 124 active components of MLC and 408 overlapping targets between the herbal formula and the disease. Core targets such as Akt1 and Bcl-2 were revealed. As indicated by 16S rRNA sequencing, the abundances of Lachnospiraceae, Lachnoclostridium, and Dorea were increased in the MLC groups (P<0.05), while the abundance of Veillonella was decreased (P<0.05). KEGG correlation analysis integrating network pharmacology and gut microbiota data showed significant enrichment of the PI3K/Akt signaling pathway. Animal experiments showed that, compared with the Mod group, body weight decreased to normal levels in the Met, MLC-M, and MLC-H groups. The estrous cycle became regular. The number of corpora lutea increased and cystic follicles decreased. Serum levels of T, FSH, and LH/FSH were reduced (P<0.05, P<0.01), while the E2 level was increased (P<0.01). Ovarian cell apoptosis was reduced (P<0.01), and the protein expression levels of p-PI3K/PI3K, p-Akt/Akt, and Bcl-2 in ovarian tissue were significantly increased, whereas Bax protein expression was significantly decreased (P<0.05, P<0.01). ConclusionMLC can regulate gut microbiota structure, effectively improve ovarian pathology in rats with obesity-type PCOS, and inhibit ovarian granulosa cell apoptosis. The mechanism may be associated with upregulation of the PI3K/Akt signaling pathway.
2.Mechanisms of Mahuang Lianqiao Chixiaodoutang in Improving Obesity-type Polycystic Ovary Syndrome in Rats Based on PI3K/Akt Signaling Pathway
Shiwei HU ; Biran ZHU ; Jinrong ZHANG ; Luyao RUAN ; Ji KUANG ; Jianghuan HUA ; Zhe LIU ; Yanyue YAO ; Ji WANG ; Min ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):21-31
ObjectiveTo investigate the mechanisms by which Mahuang Lianqiao Chixiaodoutang (MLC) improves obesity-type polycystic ovary syndrome (PCOS) through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. MethodsThirty-six female Sprague-Dawley (SD) rats were randomly divided into a blank control group (Con) and an obesity-type PCOS model preparation group. The model was induced by gavage with letrozole (1 mg·kg-1) combined with a high-fat diet (HFD). After model establishment, the obesity-type PCOS model preparation group was further divided into the model group (Mod, normal saline), metformin group (Met, 0.3 g·kg-1), low-dose MLC group (MLC-L, 4.3 g·kg-1), medium-dose MLC group (MLC-M, 8.6 g·kg-1), and high-dose MLC group (MLC-H, 17.2 g·kg-1). Active components of MLC and targets of obesity-type PCOS were screened from databases, a protein-protein interaction (PPI) network was constructed, and gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed. The gut microbiota structure was analyzed based on 16S rRNA sequencing and correlated with network pharmacology pathways. Body weight and estrous cycle were dynamically monitored. Ovarian morphology was observed by hematoxylin-eosin (HE) staining. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Enzyme-linked immunosorbent assay (ELISA) was used to detect levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), testosterone (T), and estradiol (E2). Western blot was used to detect the protein expression levels of phosphorylated PI3K/PI3K (p-PI3K/PI3K), phosphorylated Akt/Akt (p-Akt/Akt), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax). ResultsNetwork pharmacology screening identified 124 active components of MLC and 408 overlapping targets between the herbal formula and the disease. Core targets such as Akt1 and Bcl-2 were revealed. As indicated by 16S rRNA sequencing, the abundances of Lachnospiraceae, Lachnoclostridium, and Dorea were increased in the MLC groups (P<0.05), while the abundance of Veillonella was decreased (P<0.05). KEGG correlation analysis integrating network pharmacology and gut microbiota data showed significant enrichment of the PI3K/Akt signaling pathway. Animal experiments showed that, compared with the Mod group, body weight decreased to normal levels in the Met, MLC-M, and MLC-H groups. The estrous cycle became regular. The number of corpora lutea increased and cystic follicles decreased. Serum levels of T, FSH, and LH/FSH were reduced (P<0.05, P<0.01), while the E2 level was increased (P<0.01). Ovarian cell apoptosis was reduced (P<0.01), and the protein expression levels of p-PI3K/PI3K, p-Akt/Akt, and Bcl-2 in ovarian tissue were significantly increased, whereas Bax protein expression was significantly decreased (P<0.05, P<0.01). ConclusionMLC can regulate gut microbiota structure, effectively improve ovarian pathology in rats with obesity-type PCOS, and inhibit ovarian granulosa cell apoptosis. The mechanism may be associated with upregulation of the PI3K/Akt signaling pathway.
3.The parallel mediating effects of anxiety and depression states between life events and behavior problems in adolescents
Zihao YANG ; Qingqing ZHANG ; Dan WANG ; Lei ZHANG ; Hua ZHENG ; Lijing SHI ; Nana WANG ; Yihan ZHANG ; Zhenyi LI ; Min SUN ; Huimin CHEN ; Huiping CHENG ; Ruiling ZHANG ; Chuansheng WANG
Chinese Journal of Behavioral Medicine and Brain Science 2025;34(3):259-265
Objective:To explore the relationship between life events, anxiety, depression, and behavior problems in adolescents.Methods:From September to October 2022, the cluster sampling method was used to select 5 341 adolescents from 4 middle schools in Xinxiang urban area.The subjects and their parents were investigated by the adolescent self-rating life events check list (ASLEC), generalized anxiety disorder scale (GAD-7), patient health questionnaire (PHQ-9), and child behavior checklist (CBCL). SPSS 27.0 software was used for Spearman correlation analysis, and AMOS 28.0 software was used to construct the structural equation model.Results:The scores of anxiety, depression, and behavioral problems were 1 (0, 4), 1 (0, 4), and 3 (0, 10). The total score of life events was 5 (1, 13), and the dimensions scored as follows: interpersonal conflict 1 (0, 4), academic pressure 2 (0, 5), punishment 0 (0, 2), loss 0 (0, 0), health and adaptation problem 0 (0, 1), and others 0 (0, 2). There were positive correlations between life events and its dimensions, depression, anxiety and behavioral problems ( r=0.28-0.69, all P<0.01). In the overall population, anxiety and depression played parallel mediating roles in the impact of life events on behavior problems. Life events could positively predict anxiety ( β=0.68, P<0.01), and anxiety could positively predict behavior problems ( β=0.04, P=0.02). Life events could positively predict depression ( β=0.77, P<0.01), and depression could positively predict behavior problems ( β=0.18, P<0.01). The standardized total effect size of the impact of life events on behavioral problems was 0.622 (95% CI=0.564-0.675). The standardized direct effect size and indirect effect size were 0.460 (95% CI=0.374-0.539) and 0.162 (95% CI=0.108-0.218), accounting for 74.0% and 26.0%of the total effect, respectively. After stratification by gender, the results for male adolescents were consistent with the overall population, while the mediating effect of anxiety was not significant in the female adolescents. Conclusion:Life events can lead to anxiety and depression in adolescents, thereby increasing the risk of behavior problems.
4.Clinical characteristics and prognostic risk factors of patients with atrial fibrillation related to septic shock
Jiading XIA ; Liwei HUA ; Min XU ; Guobin LI ; Xin ZHENG ; Kun ZHANG
Journal of China Medical University 2025;54(7):631-637
Objective To analyze the clinical characteristics and prognostic risk factors of patients with atrial fibrillation(AF)related to septic shock admitted to the intensive care unit(ICU).Methods This retrospective cohort study included 152 patients with septic shock who were admitted to the ICU between January 2020 and December 2023.Patients were categorized into AF(n=48)and non-AF(n=104)groups based on the occurrence of AF.Clinical parameters were compared between the two groups,and variables with statistically significant differences(P<0.05)were entered into a multivariate logistic regression analysis to identify clinical features associated with AF.Patients were also stratified into survival(n=103)and death(n=49)groups based on 28-day outcomes.Variables showing signifi-cant intergroup differences(P<0.05)were further included in a multivariate model to identify independent risk factors for mortality.Kaplan-Meier survival analysis was performed using AF as a binary variable,and log-rank tests were applied to compare survival curves.Results The incidence of AF was 31.58%among patients with septic shock.Compared with the non-AF group,the AF group was older,received higher cumulative doses of vasoactive agents,and had elevated levels of lactate(Lac),N-terminal brain natriuretic peptide precursor(NT-proBNP),troponin I(cTnI),tumor necrosis factorα(TNF-α),and C-reactive protein(CRP).The AF group also had higher E/e'ratios,left ventricular ejection fraction(LVEF),Acute Physiology and Chronic Health Evaluation-Ⅱ(APACHEⅡ)scores,Sequen-tial Organ Failure Assessment(SOFA)scores,and 28-day mortality rates(all P<0.05).Multivariate logistic regression identified age(odds ratio[OR]=1.060,P=0.015),SOFA score(OR=1.525,P=0.001),TNF-α(OR=1.009,P=0.026),CRP(OR=1.008,P=0.002),and E/e'(OR=1.363,P=0.023)as independent risk factors for AF.The 28-day mortality rate was 32.24%.Compared with survivors,non-survivors had significantly higher Lac,cTnI,E/e',LVEF,and TNF-α levels,higher APACHEⅡand SOFA scores,longer ICU stays,and a higher incidence of AF(all P<0.05).Multivariate analysis identified SOFA score,cTnI,E/e',and AF as independent predictors of 28-day mortality.Kaplan-Meier analysis revealed significantly poorer survival in patients with AF(χ2=6.747,P=0.009).Conclusion AF is common in ICU patients with septic shock.Advanced age,greater organ dysfunction,elevated inflammatory markers,and diastolic dysfunction are associated with AF occurrence.Organ dysfunction,myocardial injury,diastolic dysfunction,and AF are inde-pendent predictors of mortality in this population.Greater clinical attention is warranted in patients with AF and septic shock due to their elevated risk of poor outcomes.
5.Effects of epifriedelanol on gene expression of P-glycoprotein in human colorectal adenocarcinoma cell line LS174T
Jie JIANG ; Xiao-li ZHANG ; Shi-jia XIANG ; Li-hua YAO ; Guo-ping ZHONG ; Min HUANG ; Yu-hua LI
The Chinese Journal of Clinical Pharmacology 2025;41(1):50-54
Objective To investigate the effect of epifriedelanol(Epi)on gene expression of P-glycoprotein(P-gp)in human colorectal adenocarcinoma cell line LS174T and its mechanism.Methods LS174T cells were divided into control group and experimental-L,-M,-H groups.Experimental-L,-M,-H groups were treated with 5,10,20 μmol·L-1 Epi,respectively.Control group was treated with 0.1%dimethyl sulfoxide.Polymerase chain reaction was used to detect the mRNA expression level of P-gp.Theeffect of Epi on multidrug resistance protein 1(MDR1/P-gp)luciferase activity was investigated by pregnane X receptor(PXR)-MDR1/P-gp dual luciferase reporter gene assay.In addition,Western Blot was used to detect the protein expression level of P-gp and the nuclear factor-κB(NF-κB)pathway related proteins.Results The relative expression levels of P-gp mRNA in experimental-M,-H groups and control group were 52.24±5.19,23.00±3.52 and 100.00±9.00;the relative expression levels of P-gp protein were 86.37±9.96,74.85±15.92 and 100.00±12.91;the relative activities P-gp luciferase were 230.19±41.32,203.10±52.84 and 279.67±19.20;the relative expression levels of p65(RelA/p65)in nucleus were 132.36±23.93,145.96±25.15 and 100.00±10.88;the relative expression levels of phosphorylation NF-κB inhibits protein kinase α/β(p-IKKα/β)in cytoplasm were 184.00±54.82,290.10±49.59 and 100.00±15.34;the relative expression levels of phosphorylated NF-κB inhibitory protein α(p-IκBα)in cytoplasm were 125.73±18.77,133.69±20.25 and 100.00±8.12;the relative expression levels of IκBα in cytoplasm were 78.36±14.83,70.44±14.57 and 100.00±22.82,respectively.The above indexes of experimental-M and experimental-H groups were compared with control group,and the differences were statistically significant(P<0.05,P<0.01,P<0.001).Conclusion Epi can down-regulate the gene expression of P-gp in human colorectal adenocarcinoma cell line LS174T,and the mechanism may be related to activation of NF-κB and suppression of PXR.
6.Clinical study of coronary microvascular obstruction based on cardiac magnetic resonance assessment on prognosis after emergency percutaneous coronary intervention in patients with acute ST-segment elevation myocardial infarction
Hui ZHANG ; Li WANG ; Hai-juan SHANGGUAN ; Min WANG ; Hua YAN
Chinese Journal of Interventional Cardiology 2025;33(6):327-333
Objective To assess coronary microvascular obstruction(MVO)after percutaneous coronary intervention in(PCI)patients with acute ST-segment elevation myocardial infarction(STEMI)and to investigate its value for patient prognosis.Methods We enrolled 97 patients who were hospitalized for acute STEMI at Wuhan Asia Heart Hospital from May 2021 to June 2024,underwent emergency PCI during hospitalization,and completed cardiac magnetic resonance(CMR)at a median of 7(5,8)days after the procedure.Patients were classified into MVO group(n=58)and non-MVO group(n=39)according to the results of CMR.Cox regression was used to analyse predictors of adverse events after PCI.Patients were followed for a median of 11.5(8.5,24.5)months for the occurrence of major adverse cardiovascular events(MACE,a composite outcome including readmission for heart failure,recurrent myocardial infarction,target vessel restenosis,target vessel revascularisation,and cardiac death)and secondary endpoint events(left ventricular remodelling,non-cardiac death).Results MVO was evidenced in 58 patients(59.79%).Multifactorial Cox regression analysis showed that MVO(HR 7.024,95%CI 1.408-35.027,P=0.017)and the proportion of inactive myocardium to the left ventricle(HR 1.066,95%CI 1.014-1.121,P=0.012)were the independent predictors factors for the incidence of adverse events in STEMI patients after PCI.The median follow-up time was 11.5(8.5,24.5)months.There was no statistically significant difference in the incidence of MACE between the MVO group and the non-MVO group(P=0.347).However,the MVO group had a higher incidence of secondary endpoints(32.76% vs.2.56%,P<0.001)and a higher incidence of left ventricular remodeling(29.31% vs.2.56%,P<0.001).Kaplan Meier survival analysis showed that the prognosis of the non-MVO group was significantly better than that of the MVO group(Log-rank P<0.001).Conclusions MVO after PCI in patients with acute STEMI is a good predictor of clinical prognosis.
7.Long-chain acylcoenzyme A synthase 4 regulates effects of fatty acid synthase on malignant biological behavior of esophageal cancer cells and resistance of gefitinib
Qian-hua ZHOU ; Lei JIANG ; Zhang-gui WANG ; Chao RUI ; Yi-min SHI ; Yan-xin FANG ; Qiu-shui JIN
Chinese Pharmacological Bulletin 2025;41(6):1108-1115
Aim To investigate the effect of ACSL4 on the malignant biological behavior of esophageal cancer cells and gefitinib resistance by regulating FASN,and to explore the related mechanism.Methods Thirty-five fresh esophageal cancer tissues and adjacent nor-mal tissues,and 30 esophageal cancer tissues with ge-fitinib resistance were collected.The expressions of ACSL4 and FASN were detected by qRT-PCR and im-munohistochemistry.The expression levels of ACSL4 and FASN in human normal esophageal cells HET-1 A,esophageal cancer cell lines ECA109,EC9706,TE-1 and TE-1/GR were detected by qRT-PCR.Cells in each group were constructed by liposome transfection technique,and the drug resistance and proliferation a-bility of cells were detected by cloning and CCK-8 as-say,cell apoptosis was detected by flow cytometry,cell invasion ability was detected by Transwell,and EMT pathway protein expression was detected by Western blot.Results Compared with adjacent normal tis-sues,the expression of ACSL4 and FASN genes in cancer tissues increased,and there was a positive corre-lation.The expression of ACSL4 significantly increased in ECA109,EC9706 and TE-1 cells compared with HET-1 A cells.With the increase of gefitinib concen-tration,the expression of ACSL4 in TE-1 cells gradually increased,and the expression of ACSL4 in TE-1/GR cells was higher than that of TE-1.Compared with the control group and the si-NC group,the cell proliferation and invasion ability of si-ACSL4 group decreased,the number of apoptosis increased,the expression of E-Cadherin increased,and the expression of N-Cadherin,Vimentin and β-catenin decreased.The response ex-periment showed that compared with the si-ACSL4 group and the si-ACSL4+oe-NC group,the cells in the si-ACSL4+oe-FASN group increased drug resistance,increased proliferation and invasion ability,decreased apoptosis number and decreased expression of E-Cad-herin.The expressions of N-Cadherin,Vimentin and β-catenin increased.Conclusions By down-regulating the expression of FASN,ACSL4 reverses the resistance of esophageal cancer TE-1/GR cells to gefitinib and in-hibits the proliferation,invasion and accelerates apopto-sis of TE-1/GR cells,which may be related to the regu-lation of EMT signaling pathway.
8.Significance of basophil levels in prognostic evaluation of intra-abdominal infection
Ming-min PANG ; Shao-hua FAN ; Mei-chen YAN ; Bao LIU ; Ju YANG ; Ya-nan LI ; Shi-han ZHANG ; Ting-yu MENG ; Tao GAO
Chinese Journal of Current Advances in General Surgery 2025;28(5):367-372
Objective:To assess the relationship between basophil levels and mortality in patients with intra-abdominal infection.Methods:Information on patients with intraperitoneal infection admitted to the intensive care unit were extracted from the MIMIC database.A time-dependent Cox regression model was used to adjust for confounders associated with 28-day mortality.Propensity score matching(PSM)was used to balance the baseline differences be-tween groups with different basophil levels,and a restricted cube chart(RCS)was used to show the relationship between basophil count and 28-day mortality in patients with intra-abdominal infection.Results:A total of 4403 patients with intra-abdominal infection were enrolled in the MIMIC database.Patients with high basophil levels have lower mortality than those with low basophil levels.There was an L-shaped curve between basophil level and 28-day mortality,with a cut-off value of 0.47×109/L.Cox regression analysis showed that basophil levels were an independent protective factor for mortal-ity in patients with intra-abdominal infection after adjusting for potential confounders(HR=0.586,95%CI:0.443-0.769).Protective factors for death at basophil levels remained after PSM adjusted for potential confounders(HR=0.628,95%CI:0.470-0.832).Conclusion:Basophil level is an independent protective factor for mortality in patients with intra-abdominal infection,and basophil levels should be dynamically monitored to better evaluate the prognosis of patients.
9.Pathogenesis of"wind-toxin damaging collaterals"and stage-differentiation treatment in pediatric IgA vasculitis
Shuzi ZHANG ; Hang SU ; Zhenhua YUAN ; Zichao DING ; Min TONG ; Hua LIU ; Xianqing REN
Journal of Beijing University of Traditional Chinese Medicine 2025;48(11):1556-1561
IgA vasculitis is a common childhood vasculitis disorder.Its primary clinical manifestation is cutaneous purpura,which is often accompanied by gastrointestinal and joint symptoms.Renal involvement can present as hematuria or proteinuria.This condition is recurrent and protracted,significantly affecting the health of children.The pathogenic factors in pediatric IgA vasculitis are diverse."Wind-toxin damaging collaterals"is presented as the core pathogenesis based on clinical practice and theoretical exploration.This concept essentially entails the latent attack of wind-toxin,collateral damage leading to blood extravasation,and healthy qi deficiency and lingering toxins,with the disease primarily located in the collateral vessels.The disease course is divided into three stages:acute,lingering,and recovery.Clinical practice should adhere to the pathogenesis principles and apply stage-based pattern differentiation and treatment.The acute stage involves wind-toxin attacking collaterals with dampness-heat accumulation.Treatment focuses on dispersing wind,clearing heat,and eliminating dampness to expel wind-toxin from the muscular exterior.The self-prescribed Qufeng Xiaodian Formula is a frequently selected modified formula.The lingering stage features latent wind-toxin in the collaterals and congealed accumulations in the kidney collaterals.Treatment aims to resolve wind-toxin,disperse stasis,and eliminate accumulation to remove densely accumulated wind-toxin.A modified Taohong Siwu Decoction is selected.The recovery stage involves deficient healthy qi with persistent wind assault and lingering toxins.Emphasis should be placed on cultivating the fundamental,strengthening the root,and nourishing yin,as well as supporting the healthy qi to dispel wind and expel toxins,while conditioning the body to prevent recurrence.A modified Guomin Decoction is selected.Clinical application emphasizes the combination of characteristic medicines,such as wind medicines to expel pathogens,insect medicines to identify collaterals,and vine medicines to unblock the meridians,to enhance the effects of identifying wind,resolving toxins,unblocking collaterals,and dispersing congealed accumulations.This study aims to systematically elaborate on the stage-based treatment strategy from the perspective of"wind-toxin damaging collaterals,"providing a theoretical basis and clinical practice reference for the traditional Chinese medicine diagnosis and treatment of pediatric IgA vasculitis.
10.Reliable Extraction of Seawater Nd and Hf Isotope Compositions from Fe-Mn Oxyhydroxide Fraction of Marine Sediments in the Arctic Ocean
Ying ZHANG ; Lin-Sen DONG ; Hong-Min WANG ; Xiao-Jing WANG ; Lian-Hua HE ; Yan-Guang LIU ; Ji-Hua LIU
Chinese Journal of Analytical Chemistry 2025;53(8):1380-1390
Combined seawater Hf and Nd isotope compositions have been applied as reliable tracers of water mass mixing and weathering input changes.The establishment of standardized synchronous extraction methods for Fe-Mn oxyhydroxide in sediments,which serve as effective carriers for isotopic signals of ancient seawater,is a prerequisite and key for paleoceanography research.The research material of this study was the surface sediments of the Western Arctic Ocean obtained from China's 7th Arctic Scientific Expedition,and a reliable simultaneous Nd-Hf isotope extraction method in Fe-Mn oxyhydroxide fraction was established through systematic optimization of pretreatment procedures and key extraction parameters.This research focused on analyzing the effects of pretreatment(Milli-Q water pre-wash)and key extraction parameters(leaching time,solution/solid ratios,concentration of EDTA-2Na,and concentration of mixed solution of hydroxyamine hydrochloride(HH)and acetic acid(HAc))on element extraction efficiency and isotopic composition.The experimental results indicated that the Milli-Q water pre-wash was not necessary,Fe-Mn oxyhydroxide extraction could be directly performed.Nd extraction amount in Fe-Mn oxyhydroxide fraction was not sensitive to changes in extraction conditions,while the Hf extraction amount was significantly affected by leaching time,solution/solid ratios and concentration of EDTA-2Na.The optimal conditions for synchronously extracting Nd-Hf isotopes were as follows:adding 20 mL of a mixed solution of 0.005 mol/L HH+1.5%HAc+0.03 mol/L EDTA-2Na per gram of sample,and reaction at room temperature for 3 h under shaking.Through systematic verification of 87Sr/86Sr ratio,εNd value,εHf value,Al/Nd ratio and Al/Hf ratio,it was confirmed that this method could effectively avoid interferences from residual components and accurately obtain Nd-Hf isotope signals of ancient seawater preserved in sediments.The standardized method established in this work provided reliable technical support for reconstructing water mass mixing between the Arctic,North Atlantic,and North Pacific Oceans and riverine input histories.It also provided important reference for the extraction methods of Nd and Hf isotopes from marine sources in sediments from other sea areas around the world.

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