1.Efficacy and safety of diquafosol sodium eye drops for children with dry eye wearing orthokeratology lens
Zhongming LI ; Yongchuan HE ; Mengyao WANG ; Ying LIU ; Yi REN
International Eye Science 2026;26(3):375-382
AIM: To evaluate the efficacy and safety of 3% diquafosol sodium eye drops in children wearing orthokeratology lenses and with dry eye disease(DED)or at risk of DED.METHODS: Randomized controlled trials. Children with DED or at risk of DED were randomly assigned in a 1:1 ratio to receive either 3% diquafosol sodium eye drops 6 times daily or a blank control at Chongqing Aier Children's Eye Hospital from November 2023 to November 2024. The primary endpoint was the change in the Dry Eye Questionnaire-5(DEQ-5)score from baseline at 12 wk. Secondary assessments included non-invasive breakup time(NIBUT), tear meniscus height, Schirmer's test, corneal fluorescein staining score, and axial length.RESULTS: A total of 80 participants(80 eyes)were enrolled(40 in each group), the average age of the participants was 11.11±1.88 years, with 43 females(54%)and 37 males(46%), and all completed the trial. After 12 wk, the DEQ-5 scores for the diquafosol sodium group and the blank control group were 1.88±2.02 and 2.88±2.79, respectively(P=0.079). The diquafosol sodium group demonstrated a significant improvement in DEQ-5 dryness symptom scores(-0.33±0.66 vs. 0.05±0.81, P=0.023)and NIBUT(6.18±3.73 vs. -1.09±4.40 s, P<0.001)at 12 wk. Additionally, the diquafosol sodium group showed no axial length elongation, in contrast to the blank control group, which exhibited elongation(0.00±0.08 vs. 0.05±0.10 mm, P=0.013). No other significant differences were found in the secondary endpoints. No adverse events occurred during the trial.CONCLUSION: Although no statistically significant improvements were noted in the overall DEQ-5 scores, the 3% diquafosol sodium eye drops significantly improved dryness symptoms and NIBUT when compared to the blank control group.
2.Effects of two intermittent fasting strategies on postprandial lipid metabolism in adults
Manman SHAO ; Xiaohui WEI ; Yuanchao LI ; Mingjing XU ; Tao YING ; Gengsheng HE ; Yuwei LIU
Shanghai Journal of Preventive Medicine 2025;37(1):64-71
ObjectiveTo investigate the effects and potential mechanisms of morning and evening fasting on postprandial lipid responses, a post hoc analysis based on a crossover randomized controlled trial was conducted to assess the effects of different fasting strategies on postprandial lipid metabolism in community residents in Shanghai. MethodsA total of 23 participants took part in a randomized crossover trial involving two intervention days: morning fasting and evening fasting, with a washout period of 6 days between intervention days. Two-way analysis of variance was used to test the differences in total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and the relative expression of circadian clock genes before and after the next meal under fasting. Wilcoxon rank sum tests were used to analyze the different metabolites between the two groups. Principal component analysis and Orthogonal partial least squares-discriminant analysis were conducted to evaluate the ability of metabolites to differentiate between morning fasting and evening fasting and identify the important differential metabolites. After adjusting for age, sex, and BMI, a partial correlation analysis was performed to identify metabolites associated with plasma lipids. In addition, important metabolites associated with plasma lipids were computed by pathway enrichment analysis. ResultsAfter evening fasting intervention, fasting TG level [(0.37±0.29) vs (0.27±0.18)] mmol·L-1, fasting and postprandial change values in TC [(2.74±0.47) vs (2.51±0.27)] mmol·L-1 and LDL-C [(1.32±0.38) vs (0.99±0.27)] mmol·L-1 were significantly lower than those after morning fasting (P<0.05). While, change values of fasting LDL-C [(0.89±0.37) vs (1.14±0.37)] mmol·L-1 and TG [(1.14±0.19) vs (1.28±0.17)] mmol·L-1 were significantly higher than those after morning fasting intervention (P<0.05). After fasting intervention, the relative expression of AMPK, CRY1, CLOCK, MTNR1B, AANAT, and ASMT was correlated with the amount of plasma lipid changes (P<0.05). Specifically, CLOCK and AANAT were upregulated following evening fasting and downregulated after morning fasting. Among the 217 important differential metabolites, 111 were correlated with plasma lipids, and which were primarily enriched in the cysteine and methionine metabolism pathways (P<0.05). ConclusionCompared to morning fasting, evening fasting was more effective in improving postprandial lipid responses, indicating that an evening fasting window during intermittent fasting could be conducive to cardiovascular disease prevention in adults. Meanwhile, it is suggested that morning and evening fasting may affect lipid responses through circadian rhythm oscillations and the cysteine and methionine metabolism pathways.
3.Progress in animal model studies on chronic fatigue syndrome in military seafaring operations
Shuqi CAI ; Ying HE ; Wenhui WU ; Ruisang LIU ; Yunkai ZHANG ; Yong JIAO ; Xiaomeng REN
Journal of Environmental and Occupational Medicine 2025;42(3):373-378
Chronic fatigue syndrome (CFS) is a common problem in military maritime navigation, which greatly affects the safety of military missions. The use of animal models to carry out research on the mechanism of CFS and treatment measures is a common method. This paper systematically introduced the construction methods of CFS models such as single-factor and multi-factor models, summarized common evaluation indicators of CFS, including behavioral and biochemical indicators, and summed up key characteristics of CFS animal models in military oceanic navigation combined with common causes of CFS in military contexts, such as prolonged continuous work, high-intensity physical activity, sleep deprivation, psychological stress, and extreme environmental conditions. The key characteristics of the animal models included, but not limited to, chronic fatigue, sleep disorders, impaired cognitive function, psychological stress responses, and abnormal biochemical indicators. Furthermore, this article identified future research directions for CFS animal models in military oceanic navigation to enhance the application value of the models and provide robust support for the health protection and disease prevention of military personnel.
4.Interpretation and thoughts on the formulation and revision of the standards for exogenous harmful residues in traditional Chinese medicinal materials in the Chinese Pharmacopoeia 2025 Edition
WANG Ying ; SHEN Mingrui ; LIU Yuanxi ; ZUO Tiantian ; WANG Dandan ; HE Yi ; CHENG Xianlong ; JIN Hongyu ; LIU Yongli ; WEI Feng ; MA Shuangcheng
Drug Standards of China 2025;26(1):083-092
As people’s attention to health continues to increase, the market demand for traditional Chinese medicine (TCM) is growing steadily. The quality and safety of Chinese medicinal materials have attracted unprecedented social attention. In particular, the issue of exogenous harmful residue pollution in TCM has become a hot topic of concern for both regulatory authorities and society. The Chinese Pharmacopoeia 2025 Edition further refines the detection methods and limit standards for exogenous harmful residues in TCM. This not only reflects China’s high-level emphasis on the quality and safety of TCM but also demonstrates the continuous progress made by China in the field of TCM safety supervision. Basis on this study, by systematically reviewing the development history of the detection standards for exogenous harmful residues in TCM and analyzing the revisions and updates of these detection standards in the Chinese Pharmacopoeia 2025 Edition, deeply explores the key points of the changes in the monitoring standards for exogenous harmful residues in TCM in the Chinese Pharmacopoeia 2025 Edition. Moreover, it interprets the future development directions of the detection of exogenous residues in TCM, aiming to provide a reference for the formulation of TCM safety supervision policies.
5.A prediction model for high-risk cardiovascular disease among residents aged 35 to 75 years
ZHOU Guoying ; XING Lili ; SU Ying ; LIU Hongjie ; LIU He ; WANG Di ; XUE Jinfeng ; DAI Wei ; WANG Jing ; YANG Xinghua
Journal of Preventive Medicine 2025;37(1):12-16
Objective:
To establish a prediction model for high-risk cardiovascular disease (CVD) among residents aged 35 to 75 years, so as to provide the basis for improving CVD prevention and control measures.
Methods:
Permanent residents aged 35 to 75 years were selected from Dongcheng District, Beijing Municipality using the stratified random sampling method from 2018 to 2023. Demographic information, lifestyle, waist circumference and blood biochemical indicators were collected through questionnaire surveys, physical examinations and laboratory tests. Influencing factors for high-risk CVD among residents aged 35 to 75 years were identified using a multivariable logistic regression model, and a prediction model for high-risk CVD was established. The predictive effect was evaluated using the receiver operating characteristic (ROC) curve.
Results:
A total of 6 968 individuals were surveyed, including 2 821 males (40.49%) and 4 147 females (59.51%), and had a mean age of (59.92±9.33) years. There were 1 155 high-risk CVD population, with a detection rate of 16.58%. Multivariable logistic regression analysis showed that gender, age, smoking, central obesity, systolic blood pressure, fasting blood glucose, triglyceride and low-density lipoprotein cholesterol were influencing factors for high-risk CVD among residents aged 35 to 75 years (all P<0.05). The area under the ROC curve of the established prediction model was 0.849 (95%CI: 0.834-0.863), with a sensitivity of 0.693 and a specificity of 0.863, indicating good discrimination.
Conclusion
The model constructed by eight factors including demographic characteristics, lifestyle and blood biochemical indicators has good predictive value for high-risk CVD among residents aged 35 to 75 years.
6.Discussion on the decoction and dosing methods of rhubarb root and rhizome in classical prescriptions
Zilin REN ; Changxiang LI ; Yuxiao ZHENG ; Xin LAN ; Ying LIU ; Yanhui HE ; Fafeng CHENG ; Qingguo WANG ; Xueqian WANG
Journal of Beijing University of Traditional Chinese Medicine 2025;48(1):48-54
The purpose of this paper is to explore the decoction and dosing methods of rhubarb root and rhizome in classical prescriptions and to provide a reference basis for the clinical use of rhubarb root and rhizome. By collating the relevant classical prescriptions of rhubarb root and rhizome in Shanghan Lun and Jingui Yaolüe, the relationship between its decoction and dosing methods and the syndrome was analyzed. The decoction of rhubarb root and rhizome in classical prescriptions can be divided into three categories: simultaneous decoction, decoction later, and other methods (impregnation in Mafei decoction, decoction with water from the well spring first taken in the morning, and pills). If it enters the blood level or wants to slow down, rhubarb root and rhizome should be decocted at the same time with other drugs. If it enters the qi level and wants to speed up, rhubarb root and rhizome should be decocted later. If it wants to upwardly move, rhubarb root and rhizome should be immersed in Mafei decoction. If it wants to suppress liver yang, rhubarb root and rhizome should be decocted with water from the well spring first taken in the morning. If the disease is prolonged, rhubarb root and rhizome should be taken in pill form. The dosing methods of rhubarb root and rhizome can be divided into five categories: draught, twice, three times, before meals, and unspecified. For acute and serious illnesses with excess of pathogenic qi and adequate vital qi, we choose draught. For gastrointestinal diseases, we choose to take the medicine twice. For achieving a moderate and long-lasting effect, we choose to take the medicine three times. If the disease is located in the lower part of the heart and abdomen, we choose to take it before meals. The use of rhubarb root and rhizome in clinical practice requires the selection of the appropriate decoction and dosing methods according to the location of the disease, the severity of the disease, the patient′s constitution, and the condition after taking the medicine.
7.Mechanism of Kidney-tonifying and Liver-regulating Cyclical Therapy and Formula in Improving Endometrial Receptivity during "Implantation Window" in Rats with Polycystic Ovary Syndrome via miR-140-5p/VEGF Pathway
Quan LIU ; Yiqing HE ; Ying ZHANG ; Xi WANG ; Shuo YANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(12):100-109
ObjectiveTo investigate the mechanism of kidney-tonifying and liver-regulating cyclical therapy and its formula in regulating endometrial receptivity during the "implantation window" in rats with polycystic ovary syndrome (PCOS). MethodsSix rats were randomly selected from 36 SPF SD female rats as the normal group, and the remaining rats were administered letrozole to induce a PCOS model. By using a random number method, the rats were divided into the following groups: normal group, model group, Xiaoyaosan group (11.97 g·kg-1), Sanzi Yangmo decoction group (28.35 g·kg-1), cyclical therapy group (11.97/28.35 g·kg-1), and aspirin group (8 × 10-3 mg·kg-1). After 12 days of continuous administration by gavage (equivalent to three estrous cycles), female and male rats were co-housed. On the fifth day of pregnancy, the number of blastocyst implantation in each group was counted. Hematoxylin-eosin (HE) staining was used to observe the pathological morphology of rat endometrial tissue. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of estradiol (E2) and progesterone (P) in rat serum. Western blot was used to detect the protein expression of vascular endothelial growth factor (VEGF), progesterone receptor (PR), estrogen receptor (ER), androgen receptor (AR), and integrin(ITG) αvβ3 in rat endometrial blood vessels. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was used to detect the mRNA expression of miR-140-5 P, VEGF, vascular endothelial growth factor receptor 2 (VEGFR2), PR, ER, AR, and ITGαvβ3 in rat endometrium. ResultsCompared with normal group, the estrous cycle of the rats in model group continued to be in the estrus interval and the estrous cycle lost regular changes. The endometrium was significantly thinner, the number of uterine glands and blood vessels were significantly reduced (P<0.01), and the pregnancy rate was significantly reduced. Compared with the model group, each drug group restored the regular estrous cycle to varying degrees, and the endometrial thickness and the number of blood vessels were significantly improved (P<0.01). The pregnancy rate of each drug group increased, and the effect of the cycle therapy group could reach the normal level. The results of molecular biology experiments showed that compared with the normal group, the levels of serum E2 and P in the model group were significantly decreased (P<0.01), the expression of VEGF, ER, PR and ITGαvβ3 protein was significantly decreased (P<0.05,P<0.01), the expression of AR protein was significantly increased (P<0.01), the expression of miR-140-5P and AR mRNA was significantly increased (P<0.01), and the expression of VEGF, VEGFR2, ER, PR and ITGαvβ3 mRNA was significantly decreased (P<0.01). Compared with model group, the serum E2 level in the Xiaoyaosan group was significantly increased (P<0.01).The levels of E2 and P in serum of rats in Sanzi Yangmo decoction group, cycle therapy group and aspirin group were significantly increased (P<0.01). The expression of AR protein in each drug group was significantly decreased (P<0.01). The expression of VEGF and ITGαvβ3 protein in Xiaoyaosan group was significantly increased (P<0.01). The expression of VEGF, ER and PR protein in Sanzi Yangmo decoction group was increased to varying degrees (P<0.05,P<0.01). The expression of VEGF, PR, ER and ITGαvβ3 protein in the cycle therapy group and the aspirin group increased to varying degrees (P<0.05,P<0.01). The expression of miR-140-5P and AR mRNA in each drug group was significantly decreased (P<0.01). The expression of VEGF, VEGFR2, ER, PR and ITGαvβ3 mRNA in each drug group increased to varying degrees (P<0.05,P<0.01). Compared with Xiaoyaosan group and Sanzi Yangmo decoction group, the expression of miR-140-5P, VEGFR2, ER, PR, AR and ITGαvβ3 mRNA in the cycle therapy group were significantly different (P<0.05,P<0.01). ConclusionThe kidney-tonifying and liver-regulating cyclical therapy may reduce the activity of miR-140-5P, target the upregulation of VEGF expression, mediate angiogenesis, and promote endometrial angiogenesis, thereby playing a synergistic role in improving endometrial receptivity in PCOS-induced infertility. Its efficacy in increasing pregnancy rates surpasses that of Xiaoyaosan or Sanzi Yangmo decoction used alone.
8.Mechanism of Kidney-tonifying and Liver-regulating Cyclical Therapy and Formula in Improving Endometrial Receptivity during "Implantation Window" in Rats with Polycystic Ovary Syndrome via miR-140-5p/VEGF Pathway
Quan LIU ; Yiqing HE ; Ying ZHANG ; Xi WANG ; Shuo YANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(12):100-109
ObjectiveTo investigate the mechanism of kidney-tonifying and liver-regulating cyclical therapy and its formula in regulating endometrial receptivity during the "implantation window" in rats with polycystic ovary syndrome (PCOS). MethodsSix rats were randomly selected from 36 SPF SD female rats as the normal group, and the remaining rats were administered letrozole to induce a PCOS model. By using a random number method, the rats were divided into the following groups: normal group, model group, Xiaoyaosan group (11.97 g·kg-1), Sanzi Yangmo decoction group (28.35 g·kg-1), cyclical therapy group (11.97/28.35 g·kg-1), and aspirin group (8 × 10-3 mg·kg-1). After 12 days of continuous administration by gavage (equivalent to three estrous cycles), female and male rats were co-housed. On the fifth day of pregnancy, the number of blastocyst implantation in each group was counted. Hematoxylin-eosin (HE) staining was used to observe the pathological morphology of rat endometrial tissue. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of estradiol (E2) and progesterone (P) in rat serum. Western blot was used to detect the protein expression of vascular endothelial growth factor (VEGF), progesterone receptor (PR), estrogen receptor (ER), androgen receptor (AR), and integrin(ITG) αvβ3 in rat endometrial blood vessels. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was used to detect the mRNA expression of miR-140-5 P, VEGF, vascular endothelial growth factor receptor 2 (VEGFR2), PR, ER, AR, and ITGαvβ3 in rat endometrium. ResultsCompared with normal group, the estrous cycle of the rats in model group continued to be in the estrus interval and the estrous cycle lost regular changes. The endometrium was significantly thinner, the number of uterine glands and blood vessels were significantly reduced (P<0.01), and the pregnancy rate was significantly reduced. Compared with the model group, each drug group restored the regular estrous cycle to varying degrees, and the endometrial thickness and the number of blood vessels were significantly improved (P<0.01). The pregnancy rate of each drug group increased, and the effect of the cycle therapy group could reach the normal level. The results of molecular biology experiments showed that compared with the normal group, the levels of serum E2 and P in the model group were significantly decreased (P<0.01), the expression of VEGF, ER, PR and ITGαvβ3 protein was significantly decreased (P<0.05,P<0.01), the expression of AR protein was significantly increased (P<0.01), the expression of miR-140-5P and AR mRNA was significantly increased (P<0.01), and the expression of VEGF, VEGFR2, ER, PR and ITGαvβ3 mRNA was significantly decreased (P<0.01). Compared with model group, the serum E2 level in the Xiaoyaosan group was significantly increased (P<0.01).The levels of E2 and P in serum of rats in Sanzi Yangmo decoction group, cycle therapy group and aspirin group were significantly increased (P<0.01). The expression of AR protein in each drug group was significantly decreased (P<0.01). The expression of VEGF and ITGαvβ3 protein in Xiaoyaosan group was significantly increased (P<0.01). The expression of VEGF, ER and PR protein in Sanzi Yangmo decoction group was increased to varying degrees (P<0.05,P<0.01). The expression of VEGF, PR, ER and ITGαvβ3 protein in the cycle therapy group and the aspirin group increased to varying degrees (P<0.05,P<0.01). The expression of miR-140-5P and AR mRNA in each drug group was significantly decreased (P<0.01). The expression of VEGF, VEGFR2, ER, PR and ITGαvβ3 mRNA in each drug group increased to varying degrees (P<0.05,P<0.01). Compared with Xiaoyaosan group and Sanzi Yangmo decoction group, the expression of miR-140-5P, VEGFR2, ER, PR, AR and ITGαvβ3 mRNA in the cycle therapy group were significantly different (P<0.05,P<0.01). ConclusionThe kidney-tonifying and liver-regulating cyclical therapy may reduce the activity of miR-140-5P, target the upregulation of VEGF expression, mediate angiogenesis, and promote endometrial angiogenesis, thereby playing a synergistic role in improving endometrial receptivity in PCOS-induced infertility. Its efficacy in increasing pregnancy rates surpasses that of Xiaoyaosan or Sanzi Yangmo decoction used alone.
9.Protective effect and mechanism of heat acclimation on hippocampus neuron injury in mice after exposure to electromagnetic field
Zeze WANG ; Xuesen YANG ; Ying WANG ; Yulong TAN ; Zhen LUO ; Ping LI ; Genlin HE ; Xiaoqian LIU ; Tingting SHEN ; Yishan LIU ; Xue LUO
Journal of Army Medical University 2025;47(7):629-638
Objective To investigate the protective effect and mechanism of heat acclimation(HA)on electromagnetic field(EMF)induced hippocampus neuron injury in mice.Methods Forty healthy BALB/c male mice(18~22 g,7 weeks old)were randomly divided into 4 groups(n=10):Control group(Con),HA group(34℃,30 d),EMF group(2 450 MHz,20 min/d,4 weeks)and HA+EMF group(HA preconditioning+EMF).Sucrose preference test was performed to evaluate sucrose preference levels of mice in each group.Tail suspension test and forced swimming test were utilized to observe the immobility time.Morris water maze test was conducted to determine the learning and memory capabilities.Pathological changes in the hippocampus were observed with HE staining.Immunohistochemical assay for Iba1(marker of microglia),CD68(marker of pro-inflammatory phenotype)and CD206(marker of anti-inflammatory phenotype)were used to detect the number and activation phenotype of microglia in the hippocampus.ELISA was applied to measure the levels of TNF-α,IL-1β,TGF-β and IL-10 in the hippocampus of each group.Western blotting was performed to determine the protein levels of HSP70 in the hippocampus.Results As compared with the Con group,the EMF group showed a decreased preference for sucrose(P<0.05),prolonged immobile time in the tail suspension test(P<0.01)as well as in the forced swimming test(P<0.01),extented escape latency on the 7th day(P<0.01),and a decreased time of crossing the platform(P<0.05).EMF exposure resulted in that the hippocampal neurons were in disordered arrangement,loose structure and irregular morphology,with swollen cytoplasm and condensed nuclei,swollen and more microglial cells in the hippocampus(P<0.01),and enhanced relative fluorescence intensity of CD68(P<0.01),but not in CD206 fluorescence intensity(P=0.885).All these findings suggested that activated microglia predominantly exhibited a pro-inflammatory M1 phenotype during this phase.In the hippocampus,the levels of TNF-α and IL-1β were significantly increased,while the levels of IL-10 and TGF-β were significantly decreased(P<0.01).HA treatment reversed the conditions induced by EMF exposure,including better preference for sucrose(P<0.01),shorten immobile time in tail suspension test(P<0.05)and forced swimming test(P<0.01),less escape latency on the 7th day(P<0.01),and improved hippocampal cell injuries.Compared with the Con group,there were more microglial cells in the hippocampus in the HA+EMF group,with increased relative fluorescence intensity of M2 phenotype marker CD206(P<0.01)and decreased CD68 fluorescence intensity(P<0.01).HA treatment also significantly decreased the expression of TNF-α and IL-1β levels(P<0.01),increased the expression of IL-10 and TGF-β(P<0.01),and elevated the protein level of HSP70(P<0.01)when compared with the EMF group.Conclusion HA may ameliorate EMF-induced hippocampus neurons injury in mice by altering the phenotype of activated microglia and inhibiting inflammatory responses.
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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