Land use and spatial contiguity are key driven factors of antibiotic multimedia patterns in the megacity river network.

The widespread spread of antibiotics in the environment poses a growing threat to human health. This study investigated the distribution and fate of antibiotics concerning land use characteristics, hydrological conditions, and spatial contiguity within a megacity river network. Temporally, the average concentrations of twenty antibiotics in water (354 ng/L), suspended particulate matter (SPM) (46 ng/L), and sediment (151 ng/g) during dry season were notably higher than that in the corresponding environment media (water: 127 ng/L, SPM: 2 ng/L, and sediment: 49 ng/g) during the wet season. Moreover, the inter-annual variation of antibiotics in water showed a decreasing trend. Spatially, substantial antibiotic contamination was observed in a human-intensive watershed, particularly in the upstream and central city sections. The macrolides in water were most affected by land use types and hydrological processes. Antibiotic contamination in water exhibited a stronger spatial autocorrelation compared to other media. Nevertheless, the interconnectedness of antibiotic contamination in sediments during the wet season warrants attention, and relevant authorities should enhance environmental monitoring in watersheds with pollution hotspots. Certain antibiotics, such as sulfamethoxazole, enrofloxacin, and florfenicol, were transported via urban rivers to the ocean, potentially posing environmental risks to coastal water quality. Local sources accounted for the predominant portion (>50 %) of most antibiotics in various media. The correlation distances of antibiotics in waters during the wet season could screen ecological risk prioritization in aquatic environments.

Polystyrene microplastics with absorbed nonylphenol induce intestinal dysfunction in human Caco-2 cells.

Due to the massive production and use of plastic, the chronic and evolving exposure to microplastics in our daily lives is omnipresent. Nonylphenol (NP), a persistent organic pollutant, may change toxicity when it co-exists with microplastics. In this study, polystyrene microplastics (PS-MPs), either alone or with pre-absorbed NP, generated oxidative stress and inflammatory lesions to Caco-2 cells, as well as affecting proliferation via the MAPK signaling pathway and causing apoptosis. Damage to cell membrane integrity and intestinal barrier (marked by lower transepithelial electric resistance, greater bypass transport, and tight junction structural changes) leads to enhanced internalization risk of PS-MPs. Some important intestinal functions including nutrient absorption and xenobiotic protection were also harmed. It is worth noting that the exposure of PS-MPs with a diameter of 0.1 µm improved intestinal functions quickly but acted as a chemosensitizer for a long time, inhibiting cell perception of other toxic substances and making the cells more vulnerable.

Effect of Ticagrelor versus Clopidogrel on All-Cause and Cardiovascular Mortality in Acute Coronary Syndrome Patients with Hyperuricemia.

BACKGROUND AND OBJECTIVE: The relationship between hyperuricemia and mortality in patients with acute coronary syndrome (ACS) is considerably controversial. Additionally, the strategy of dual antiplatelet therapy (DAPT) has not been evaluated in patients with ACS with hyperuricemia. This study aims to evaluate the impact of hyperuricemia on the prognosis of ACS and explore the efficacy of ticagrelor compared with clopidogrel in patients with hyperuricemia. METHODS: The study enrolled 4319 patients divided into hyperuricemia (HUA, n = 1060) and normouricemia (NUA, n = 3259) groups. The inverse probability of treatment weighting (IPTW)-adjusted Cox regression analysis was used to evaluate the impact of ticagrelor versus clopidogrel on all-cause and cardiovascular mortality. RESULTS: Hyperuricemia significantly increased the risk of all-cause death compared with patients with NUA at 7 days [adjusted hazard ratio (HR): 4.292, 95% confidence interval (CI) 1.727-10.67]; P = 0.002), 14 days (adjusted HR: 2.871, 95% CI 1.326-6.219; P = 0.0074), 30 days (adjusted HR: 2.168, 95% CI 1.056-4.453; P = 0.035), 3 months (adjusted HR: 2.018, 95% CI 1.152-3.533; P = 0.0144) and 1 year (adjusted HR: 1.702, 95% CI 1.137-2.548; P = 0.009). No significant difference was found between ticagrelor and clopidogrel in 1-year all-cause mortality [7.0% versus 5.5%, adjusted HR: 1.114 (95% CI 0.609-2.037), P = 0.725] among patients with concomitant hyperuricemia. CONCLUSION: Hyperuricemia was independently related to an increased risk of all-cause and cardiovascular death in patients with ACS undergoing PCI. At 1-year follow-up, there were no significant differences between ticagrelor and clopidogrel concerning all-cause and cardiovascular death in patients with hyperuricemia.

Urban agglomerations as an environmental dimension of antibiotics transmission through the "One Health" lens.

The spatiotemporal distributions of antibiotics in different media have been widely reported; however, their occurrence in the environmental dimension of the Chinese urban agglomerations has received less attention, especially in bioaccumulation and health risks of antibiotics through the "One Health" lens. The review presents the current knowledge on the environmental occurrence, bioaccumulation, as well as health exposure risks in urban agglomerations through the "One Health" lens, and identifies current information gaps. The reviewed studies suggested antibiotic concentrations in water and soil were more sensitive to social indicators of urban agglomerations than those in sediment. The ecological risk and resistance risk of antibiotics in water were much higher than those of sediments, and the high-risk phenomenon occurred at a higher frequency in urban agglomerations. Erythromycin-H2O (ETM-H2O), amoxicillin (AMOX) and norfloxacin (NFC) were priority-controlled antibiotics in urban waters. Tetracyclines (TCs) posed medium to high risks to soil organisms in the soil of urban agglomerations. Health risk evaluation based on dietary intake showed that children had the highest dietary intake of antibiotics in urban agglomerations. The health risk of antibiotics was higher in children than in other age groups. Our results also demonstrated that dietary structure might impact health risks associated with target antibiotics in urban agglomerations to some extent.

Using machine learning to predict adverse events in acute coronary syndrome: A retrospective study.

BACKGROUND: Up to 30% of patients with acute coronary syndrome (ACS) die from adverse events, mainly renal failure and myocardial infarction (MI). Accurate prediction of adverse events is therefore essential to improve patient prognosis. HYPOTHESIS: Machine learning (ML) methods can accurately identify risk factors and predict adverse events. METHODS: A total of 5240 patients diagnosed with ACS who underwent PCI were enrolled and followed for 1 year. Support vector machine, extreme gradient boosting, adaptive boosting, K-nearest neighbors, random forest, decision tree, categorical boosting, and linear discriminant analysis (LDA) were developed with 10-fold cross-validation to predict acute kidney injury (AKI), MI during hospitalization, and all-cause mortality within 1 year. Features with mean Shapley Additive exPlanations score >0.1 were screened by XGBoost method as input for model construction. Accuracy, F1 score, area under curve (AUC), and precision/recall curve were used to evaluate the performance of the models. RESULTS: Overall, 2.6% of patients died within 1 year, 4.2% had AKI, and 4.7% had MI during hospitalization. The LDA model was superior to the other seven ML models, with an AUC of 0.83, F1 score of 0.90, accuracy of 0.85, recall of 0.85, specificity of 0.68, and precision of 0.99 in predicting all-cause mortality. For AKI and MI, the LDA model also showed good discriminating capacity with an AUC of 0.74. CONCLUSION: The LDA model, using easily accessible variables from in-hospital patients, showed the potential to effectively predict the risk of adverse events and mortality within 1 year in ACS patients after PCI.

Simulation and risk assessment of arsenic by Hydrus-3D and CalTOX in a typical brownfield site.

Accurate quantification of arsenic migration and accumulation in brownfield site is critical for environmental management and soil remediation. However, the researches simulating arsenic in brownfield site in China are limited due to sparse data and complex migration behaviors. In this study, we simulated historic arsenic contamination using Hydrus-3D in an abandoned brownfield site in Hebei, China, from 1972 to 2019. Atmospheric discharge, wastewater leakage, solid waste discharge and tank leakage were calculated according to the factory processes for model simulation. Based on the results of Hydrus-3D, we assessed health risk of arsenic in this site. The results showed that total arsenic input to the soil surface from 4 pathways was 24.6 tons, the solid waste discharge was the highest contributor. The accumulation process mainly occurred in the unsaturated zone due to clay and silty clay absorbed arsenic and thus slow down the migration process. While in the saturation zone, abundant groundwater promoted migration of arsenic, resulting in widespread distribution of contaminated area. The model results represented good performance between simulated and measured values. Sensitivity analysis indicated that adsorption constant and water conductivity were the most influential parameters. Heath risk assessment showed that arsenic contamination continues to threaten resident health.

The deposition mapping of polycyclic aromatic hydrocarbons in megacity Shanghai, China.

The deposition of polycyclic aromatic hydrocarbon (PAHs) has far-reaching impacts on Earth's surface system and human health. However, a comprehensive understanding of PAHs' deposition in a high urbanized area is still lacking because of limited field measurements data and rough resolution of current models. In this research, a deposition map of PAHs with a resolution of 2 × 2 km in megacity Shanghai, China was established. Gridded annual total deposition of PAHs from July 2020 to June 2021 ranged from 385 to 10,631 ng/(m2·d), with a mean value of 2,611 ng/(m2·d). The highest PAHs deposition was found over the downtown Shanghai, which received 4.3 times the deposition flux of outlying areas. About 77 % of area in Shanghai was dominated by wet deposition which accounted for 62 % of total deposition in Shanghai. The total deposition showed a trend of summer>fall>spring>winter, which was similar to that of the amount of rain. Source apportionment and geographically weighted regression analysis showed that built-up land and human activities are key driving factors of PAHs' deposition in Shanghai. Our results suggest that intensive human activities could alter the PAHs deposition distribution in Shanghai, and improve the understanding of PAHs' environmental behavior in high urbanized area.

Specific Loss of ABCA1 (ATP-Binding Cassette Transporter A1) Suppresses TCR (T-Cell Receptor) Signaling and Provides Protection Against Atherosclerosis.

BACKGROUND: ABCA1 (ATP-binding cassette transporter A1) mediates cholesterol efflux to apo AI to maintain cellular cholesterol homeostasis. The current study aims to investigate whether T-cell-specific deletion of ABCA1 modulates the phenotype/function of T cells and the development of atherosclerosis. METHODS: Mice with T-cell-specific deletion of ABCA1 on low-density lipoprotein receptor knockout (Ldlr-/-) background (Abca1CD4-/CD4-Ldlr-/-) were generated by multiple steps of (cross)-breedings among Abca1flox/flox, CD4-Cre, and Ldlr-/- mice. RESULTS: Deletions of ABCA1 greatly suppressed cholesterol efflux to apo AI but slightly reduced membrane lipid rafts on T cells probably due to the upregulation of ABCG1. Moreover, ABCA1 deficiency impaired TCR (T-cell receptor) signaling and inhibited the survival and proliferation of T cells as well as the formation of effector memory T cells. Despite the comparable levels of plasma total cholesterol after Western-type diet feeding, Abca1CD4-/CD4-Ldlr-/- mice showed significantly attenuated arterial accumulations of T cells and smaller atherosclerotic lesions than Abca1+/+Ldlr-/-controls, which were associated with reduced surface CCR5 (CC motif chemokine receptor 5) and CXCR3 (CXC motif chemokine receptor 3), decreased antiapoptotic Bcl-2 (B-cell lymphoma 2) and Bcl-xL (B-cell lymphoma extra-large), and hampered abilities to produce IL (interleukin)-2 and IFN (interferon)-γ by ABCA1-deficient T cells. CONCLUSIONS: ABCA1 is essential for T-cell cholesterol homeostasis. Deletion of ABCA1 in T cells impairs TCR signaling, suppresses the survival, proliferation, differentiation, and function of T cells, thereby providing atheroprotection in vivo.

[Effect of "nape seven needles" on expression of hypoxia inducible factor-1α and Notch1 in cervical intervertebral disc degeneration rats].

OBJECTIVE: To observe the effect of "nape seven needles" on the expressions of hypoxia inducible factor-1α (HIF-1α) and Notch1 in cervical intervertebral disc of cervical disc degeneration (CDD) rats, so as to reveal its underlying mecha-nisms in improving CDD. METHODS: SD male rats were randomly divided into normal, model, non-acupoint and nape seven needles groups, with 10 rats in each group. Staticdynamic imbalance method was used to establish CDD model. Rats in the nape se-ven needles group were treated with acupuncture at "Fengfu"(GV16), and bilateral "Fengchi"(GB20), "Wangu"(GB12) and "Tianzhu"(BL10), and rats in the non-acupoint group received acupuncture at the sham acupoints at the caudal tip and armpit, both for 20 min, 6 days a week for 4 weeks. After intervention, tilted plane test and spiral CT were used to assess the neck movement function and cervical degeneration degree of rats; immunohistochemistry was used to observe the protein expression levels of HIF-1α and Notch1 in cervical discs tissue; Western blot and real-time quantitative PCR were used to detect the protein and mRNA expression levels of HIF-1α and Notch1 in cervical discs tissue, respectively. RESULTS: After modeling, the cervical curvature was straightened, with narrowed intervertebral space, rough and hardened articular surface, osteophytes, and blurred articular space and articular process, which was relatively milder in the nape seven needles group. Compared with the normal group, the angle of tilted plane was significantly reduced (P<0.05), while cervical scores, HIF-1α mRNA expression level in cervical intervertebral disc tissue were significantly increased (P<0.05) in the model group. Compared with the model and the non-acupoint groups, cervical scores were significantly reduced (P<0.05), while the angle of tilted plane, HIF-1α and Notch1 positive expressions, HIF-1α mRNA expression level, Notch1 protein and mRNA expression levels in cervical intervertebral disc tissue were significantly increased (P<0.05) in the nape seven needles group. CONCLUSION: Acupuncture of "nape seven needles" can reduce the degree of cervical degeneration in rats, which was possibly associated with its effects in up-regulating the expressions of HIF-1α and Notch1 in cervical intervertebral disc tissue, promoting the proliferation and recovery of endogenous cells in nucleus pulposus.

Corrigendum: The link between English foreign language teacher's professional identity and their critical thinking that leads to teacher's success in the Chinese context: Leaders motivational language as a moderator.

[This corrects the article DOI: 10.3389/fpsyg.2022.983215.].

The link between English foreign language teacher's professional identity and their critical thinking that leads to teacher's success in the Chinese context: Leaders motivational language as a moderator.

The purpose of this study is to examine the link between English foreign language teacher's professional identity and employee success via mediating role of critical thinking. Further, we examined the moderating role of leader motivational language between employee professional identity and critical thing and also indirect effect on employee success via critical thinking. We collected data from Chinese MNC's school by using time lagged study design. We used hierarchical linear regression for direct hypotheses and Hayes PROCESS model's for mediation, moderation, and mediation moderation analysis. The results show that there is positive relation between employee's professional identity and teacher's success. Further, critical thinking mediates the link between professional identity and employee success. The results of the moderated mediation analysis show that critical thinking mediated the interaction of employee's professional identity and leader's motivational language on teacher's success.

Embryological Characteristics of Human Oocytes With Agar-Like Zona Pellucida and Its Clinical Treatment Strategy.

Zona pellucida (ZP) abnormalities are the cause of low fertility or infertility, agar-like ZP is more common in abnormal ZP. The purpose of this exploration is to systematically analyze the fertilization competence of agar-like ZP oocytes, the development characteristics of subsequent embryos as well as the results of embryo transfer, aiming to explore effective clinical treatment strategies. A total of 58 patients with agar-like ZP were set as the case group and the control group involved 3866 patients, in which the patients' oocytes presented normal ZP. BMI, basal hormone levels, and hormone levels were similar in both groups. The case patients suffered significantly longer infertility years than control (p<0.05), and most patients were diagnosed with pelvic inflammatory diseases. A distinct difference was observed in the structure of oocyte corona cumulus complexes between the two groups. The embryo development parameters, which include the rates of cleavage, high-quality embryo, blastocyst, and high-quality blastocyst in the case group were greatly lower than that in the control group (p<0.05). The rates of cumulative clinical pregnancy and live birth were comparable between the two groups. In the subsequent follow-up, thirty-four of the 58 patients receiving intracytoplasmic single sperm injection (ICSI) or early rescue ICSI (R-ICSI) treatment successfully gave birth to babies, and all of the newborns were with no neonatal defects. In addition, the fertilization rate of the R-ICSI group was significantly lower than that of the ICSI group (p<0.05). The occurrence of agar-like ZP impairs the development competence of human oocytes, however, the human oocytes with agar-like ZP can develop into healthy offspring, and an ICSI regimen is the optimal treatment strategy for them.

A pharmacokinetic study to comparatively evaluate the bioequivalence and safety of a humanized recombinant monoclonal antibody targeting human epidermal growth factor receptor-2 with the reference Herceptin in healthy Chinese subjects.

PURPOSE: This study aimed to compare the safety, tolerability, pharmacokinetics (PK), and bioequivalence of a test humanized recombinant monoclonal antibody targeting human epidermal growth factor receptor-2 (HER-2) with the reference Herceptin®. MATERIALS AND METHODS: The trial consisted of two parts (part I and part II). Part I was an open-label, sequential-cohort dose-escalation study, where 16 healthy subjects were either intravenously infused with QLHER2 (test) at single doses escalating from 0.2 to 6 mg/kg (0.2, 1, 2, 4, and 6 mg/kg) or given 4 mg/kg Herceptin (reference) for evaluating the safety, tolerability, and PK of QLHER2. Part II was a randomized, double-blind, parallel-group study to evaluate the bioequivalence of QLHER2 and Herceptin in 60 subjects. RESULTS: Following a 1.5-h intravenous infusion of single ascending doses of QLHER2 (1, 2, 4, or 6 mg/kg) in part I, Cmax and Tmax were 19.43-120.01 µg/mL and 68.91-157.87 h, respectively. AUC0-t and CL were 1.91-34.21 h·µg/mL and 0.54-0.12 mL/h/kg, indicating lower clearance at higher doses, with a greater than proportional increase in AUC0-t and t1/2 of 68.91-157.87 h. In part II, serum concentrations were comparable between QLHER2 and Herceptin over a 70-day sampling period, and the QLHER2/Herceptin ratios of Cmax and AUC0-t were 105.90% [90% confidence interval (CI): 95.69%-117.26%] and 95.79% (90% CI: 87.74%-106.40%), respectively. CONCLUSION: The 90% CI value of Cmax and AUC0-t for QLHER2/Herceptin ratio ranged between 80.0%-125.00%, indicating that QLHER2 was bioequivalent to Herceptin. These results support further evaluation of QLHER2. Trial registration number: ChiCTR2000041577 and ChiCTR2100041802. Date of registration: 30th December, 2020 and 5th January 2021.

The temporal distribution of platinum group elements (PGEs) in PM2.5.

In this paper, Changji, Xinjiang, northwest China, was selected as the study area, and platinum group elements (PGEs) in PM2.5 were quantified by ICP-MS using microwave digestion. The results indicated that the average concentrations (and range) of Rh, Pd, and Pt in PM2.5 were 0.21 (n.d. -1.41) ng/m3, 8.09 (n.d. -59.50) ng/m3, and 0.12 (n.d. -0.83) ng/m3, respectively. The concentration of Pd was significantly higher than Rh and Pt. Moreover, the seasonal variations of Rh and Pd were the same: highest in summer and lower in other seasons. However, the seasonal variation of Pt was opposite to that of Rh and Pd: highest in winter and lower in other seasons. Seasonal differences in emission sources of PGEs and the climatic characteristics of arid regions played important roles in the seasonal changes of PGEs. Rh and Pd had a common source and similar diurnal variation. The major influencing factors were traffic volume and meteorological conditions. The diurnal variation regularity of Pt was different from Rh and Pd. The superimposed effect of vehicle exhaust emissions and coal-fired emissions was the main reason why the diurnal variation of Pt was more complicated than those of Rh and Pd. The diurnal concentration of Pt varied with the seasons. It is caused by seasonal coal combustion and meteorological conditions.

Acupuncture plus massage for cervicogenic headache: A protocol for systematic review and meta-analysis.

BACKGROUND: Cervicogenic headache (CGH), one of the most common headaches. It is characterized by pain starting from the neck and gradually involving the eyes, frontal and temporal regions. Acupuncture and massage therapy has been widely used in the treatment of CGH, the purpose of this study was to evaluate the effectiveness and safety of acupuncture combined with massage in the treatment of CGH. METHODS: The databases of PubMed, Embase, Cochrane library, Medicine, Web of Science, China National Knowledge Infrastructure, Wan-Fang Database, China Biomedical Literature Service System, and Chongqing VIP Chinese Science will be searched. This study will include randomized controlled trials of acupuncture combined with massage in the treatment of CGH published before November 2021. The primary outcomes included the overall efficiency, visual simulation score, neck activity score, quality of life score, and adverse reactions as secondary outcomes were assessed. Cochrane bias risk assessment tool will be used for literature data screening and quality evaluation, and using RevMan5.4 to collect data for statistical analysis. We then will use the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the overall quality of evidence supporting the primary outcomes. RESULTS: This systematic review will provide a high-quality synthesis to evaluate the efficacy and safety of acupuncture combined with massage therapy in the treatment of CGH, providing a reference for the safe and effective treatment plan. CONCLUSION: This study provides evidence that acupuncture combined with massage is effective and safe for patients with CGH. SYSTEMATIC REVIEW REGISTRATION: INPLASY2021120049U1.

Whole-Brain Volume CT Angiography can Effectively Detect Early Ischemic Cerebrovascular Diseases.

OBJECTIVE: To investigate the role of whole-brain volume computed tomography (CT) perfusion in assessing early ischemic cerebrovascular diseases. MATERIALS AND METHODS: Seventy-two patients with early ischemic cerebrovascular diseases who had undergone routine CT scan and 320-row volume CT whole-brain perfusion imaging within 8 h after admission were retrospectively enrolled in this one-center case-sectional study. The perfusion parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and dynamic CT angiogram (4D-CTA) were obtained and analyzed. RESULTS: Among 72 patients, 29 cases with 37 cerebral ischemic lesions were found in plain CT scan, whereas 51 cases with 76 lesions were found in whole-brain CT perfusion, with 30.6% more patients being detected. The CBF value was significantly lower in the abnormal than normal corresponding perfusion area in the healthy hemisphere (P<0.05), while the MTT and TTP values were significantly higher in the abnormal than the normal corresponding area (P<0.05). 4D-CTA image suggested that 59 cases had different degrees of stenosis or occlusion, including 11 mild, 18 moderate, 21 severe, and 9 occlusive cases. Four-D-CTA imaging could detect significantly (P<0.05) more patients with abnormal perfusion in severe cerebral vascular stenosis or occlusion than those with no, mild or moderate stenosis (93.33% vs. 16.67%) (P<0.05). The stenosis of intracranial and carotid arteries was positively correlated with MTT and TTP values (P<0.05). CONCLUSION: Whole-brain volume CT angiography can comprehensively display early cerebral ischemic lesions, cerebral blood perfusion status, and cerebral vascular stenosis, providing valuable information for early detection of ischemic cerebral diseases and appropriate treatment planning.

Occurrence and cross-interface transfer of phthalate esters in the mangrove wetland in Dongzhai Harbor, China.

Phthalate esters (PAEs), the most widely used plasticizers, are extensively present in various environmental media, and are continuously transported from land to sea. However, PAEs have not been well characterized in multiple media in mangrove wetlands, an important land-sea interface. This study investigated the distribution and transfer of six PAEs in water, sediment, mangroves, and fish in Dongzhai Harbor. The mangrove forest in Dongzhai Harbor is the largest in China and is surrounded by shrimp ponds and villages. PAEs are ubiquitous in the study area. The mean concentration range of ∑6PAEs was 0.31-1.52 µg/L in water, 450-2096 µg/kg dry weight (dw) in sediment, 210-937 µg/kg dw in mangrove plants, and not detected (n.d.) -205 µg/kg in fish. Among the six PAEs, di-n-butyl phthalate (DBP) and di-ethylhexyl phthalate (DEHP) were predominant. The concentrations of the PAEs in mangrove plants tended to decrease from the river and coast to tidal gullies, which might be related to the periodic inundation of tides. A study of PAEs bioaccumulation showed that the concentration of PAEs in herbivorous fish was higher than that in carnivorous fish. In the same species, larger individuals had a lower concentration of ∑6PAEs. Di-n-octyl phthalate (DnOP) and DEHP tended to transfer from water to sediments, while the four less-hydrophobic PAEs, such as DBP, were more likely to be released from sediments to water. Our results can provide important information of the distribution and fate of PAEs in mangrove wetlands.

The effect of rainfall runoff on phase partition of palladium in receiving water bodies and the underlying influential mechanism.

The influx of rainfall runoff intensifies phase partition of the pollutant in receiving water bodies, and the phase partition plays an important role in the speciation transformation and spatial partition of pollutants. In this study, the Meishe River on Hainan Island, China, was adopted as the research area, and palladium (Pd) was selected as the target pollutant. The purpose of this study was to explore phase partition of Pd in receiving water bodies and the underlying influential mechanism. The partition coefficients (Kds) of Pd between water and suspended particulate matter in receiving water bodies and rainfall runoff were 0.74 (0.1 × 10-2 - 8.75) and 2.74 (0.5 × 10-2 - 15.70), respectively. These results indicated that Pd dominated the dissolved phase in the receiving water bodies and that Pd dominated the particulate phase in rainfall runoff. Variations in the Kd value of Pd in the receiving water bodies were relatively smooth over time during the precipitation events in May and June. There were no significant differences in phase partition of Pd between the receiving water bodies and rainfall runoff. The Kd value for Pd in the receiving water bodies showed a fluctuating upward trend over time during the precipitation events in August, and the difference in Kd values of Pd between the receiving water bodies and the rainfall runoff were large. Variations in the Kd value of Pd among sections of the receiving water bodies could be roughly divided into two categories, namely, U and inverted-U types. After rainfall runoff converged for 20-25 min, the Pd phase transitions were more frequent within 7 m downstream of the outfall. The Kd value of Pd in the receiving water bodies was correlated with pH, Eh, and total suspended solid (TSS), and the correlation coefficients were 0.52, -0.57, and 0.84, respectively (p < 0.05). Compared with rainfall runoff, pH, Eh, TSS had less influence on phase partition of Pd in receiving water bodies. This might be attributed to the dilution effect of natural water and the unique dynamic mechanism of rivers.