Deliberate self-harm among pediatric psychiatric inpatients in China: A single-center retrospective study.

BACKGROUND: For children and adolescents, deliberate self-harm (DSH) is becoming a mental health problem of concern. Despite several studies on the prevalence and factors of DSH in the world, there is little information on DSH among children and adolescents in China. This study explores the prevalence, types, associated risk factors and tendency of DSH in pediatric psychiatric inpatients in China. AIM: To understand the situation of DSH among hospitalized children and adolescents and its related factors. METHODS: In this study, we retrospectively studied 1414 hospitalized children and adolescents with mental illness at Xiamen Mental Health Center from 2014 to 2019, extracted the demographic and clinical data of all patients, and analyzed clinical risk factors of DSH. RESULTS: A total of 239 (16.90%) patients engaged in at least one type of DSH in our study. Cutting (n = 115, 48.12%) was the most common type of DSH. Females (n = 171, 71.55%) were more likely to engage in DSH than males (n = 68, 28.45%). DSH was positively associated with depressive disorders [OR = 3.845 (2.196-6.732); P < 0.01], female [OR = 2.536 (1.815-3.542); P < 0.01], parental marital status [OR = 5.387 (2.254-12.875); P < 0.01] and negative family history of psychiatric illness [OR = 7.767 (2.952-20.433); P < 0.01], but not with occupation, substance use and history of physical abuse. CONCLUSION: Our findings suggest that for patients with depression, females, an abnormal marriage of parents, and no history of mental illness, attention should be paid to the occurrence of DSH.

Enhanced performance of quantum dot light-emitting diodes enabled by zirconium doped SnO2 as electron transport layers.

Next-generation display and lighting based on quantum dot light-emitting diodes (QLEDs) require a balanced electron injection of electron transport layers (ETLs). However, classical ZnO nanoparticles (NPs) as ETLs face inherent defects such as excessive electron injection and positive aging effects, urgently requiring the development of new types of ETL materials. Here, we show that high stability SnO2 NPs as ETL can significantly improve the QLED performance to 100567 cd·m-2 luminance, 14.3% maximum external quantum efficiency, and 13.1 cd·A-1 maximum current efficiency using traditional device structures after optimizing the film thickness and annealing the temperature. Furthermore, experimental tests reveal that by doping Zr4+ ions, the size of SnO2 NPs will reduce, dispersion will improve, and energy level will shift up. As expected, when using Zr-SnO2 NPs as the ETL, the maximum external quantum efficiency can reach 16.6%, which is close to the state-of-the-art QLEDs based on ZnO ETL. This work opens the door for developing novel, to the best of our knowledge, type ETLs for QLEDs.

Cancer screening in hospitalized ischemic stroke patients: a multicenter study focused on multiparametric analysis to improve management of occult cancers.

Background/aims: The reciprocal promotion of cancer and stroke occurs due to changes in shared risk factors, such as metabolic pathways and molecular targets, creating a "vicious cycle." Cancer plays a direct or indirect role in the pathogenesis of ischemic stroke (IS), along with the reactive medical approach used in the treatment and clinical management of IS patients, resulting in clinical challenges associated with occult cancer in these patients. The lack of reliable and simple tools hinders the effectiveness of the predictive, preventive, and personalized medicine (PPPM/3PM) approach. Therefore, we conducted a multicenter study that focused on multiparametric analysis to facilitate early diagnosis of occult cancer and personalized treatment for stroke associated with cancer. Methods: Admission routine clinical examination indicators of IS patients were retrospectively collated from the electronic medical records. The training dataset comprised 136 IS patients with concurrent cancer, matched at a 1:1 ratio with a control group. The risk of occult cancer in IS patients was assessed through logistic regression and five alternative machine-learning models. Subsequently, select the model with the highest predictive efficacy to create a nomogram, which is a quantitative tool for predicting diagnosis in clinical practice. Internal validation employed a ten-fold cross-validation, while external validation involved 239 IS patients from six centers. Validation encompassed receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and comparison with models from prior research. Results: The ultimate prediction model was based on logistic regression and incorporated the following variables: regions of ischemic lesions, multiple vascular territories, hypertension, D-dimer, fibrinogen (FIB), and hemoglobin (Hb). The area under the ROC curve (AUC) for the nomogram was 0.871 in the training dataset and 0.834 in the external test dataset. Both calibration curves and DCA underscored the nomogram's strong performance. Conclusions: The nomogram enables early occult cancer diagnosis in hospitalized IS patients and helps to accurately identify the cause of IS, while the promotion of IS stratification makes personalized treatment feasible. The online nomogram based on routine clinical examination indicators of IS patients offered a cost-effective platform for secondary care in the framework of PPPM. Supplementary Information: The online version contains supplementary material available at 10.1007/s13167-024-00354-8.

One-Pot Synthesis of N-Doped NiO for Enhanced Photocatalytic CO2 Reduction with Efficient Charge Transfer.

The green and clean sunlight-driven catalytic conversion of CO2 into high-value-added chemicals can simultaneously solve the greenhouse effect and energy problems. The controllable preparation of semiconductor catalyst materials and the study of refined structures are of great significance for the in-depth understanding of solar-energy-conversion technology. In this study, we prepared nitrogen-doped NiO semiconductors using a one-pot molten-salt method. The research shows that the molten-salt system made NiO change from p-type to n-type. In addition, nitrogen doping enhanced the adsorption of CO2 on NiO and increased the separation of photogenerated carriers on the NiO. It synergistically optimized the CO2-reduction system and achieved highly active and selective CO2 photoreduction. The CO yield on the optimal nitrogen-doped photocatalyst was 235 µmol·g-1·h-1 (selectivity 98%), which was 16.8 times that of the p-type NiO and 2.4 times that of the n-type NiO. This can be attributed to the fact that the nitrogen doping enhanced the oxygen vacancies of the NiOs and their ability to adsorb and activate CO2 molecules. Photoelectrochemical characterization also confirmed that the nitrogen-doped NiO had excellent electron -transfer and separation properties. This study provides a reference for improving NiO-based semiconductors for photocatalytic CO2 reduction.

Patent foramen ovale-associated stroke repeatedly misdiagnosed as cerebral small vessel disease: A case report.

BACKGROUND: Transthoracic echocardiography (TTE) is the most commonly used screening method for cardiac structural abnormalities. However, it may lead to a missed diagnosis of partial patent foramen ovale (PFO)-associated stroke. CASE PRESENTATION: A 60-year-old male was admitted to the hospital for recurrent left limb weakness with or without slurred speech for 14 months. No stroke-related cardiac structural abnormality was detected during repeated TTE, and the patient was diagnosed with cerebral small vessel disease. Finally, right-to-left shunt was detected by contrast-enhanced transcranial Doppler. Subsequently, the patient was diagnosed with PFO-associated stroke by transesophageal echocardiography and contrast transesophageal echocardiography. CONCLUSIONS: TTE has a low detection rate of PFO, such that it is easily missed. Contrast-enhanced transcranial Doppler is easy to operate and should be promoted as a supplementary measure to stroke etiological investigation and primary PFO screening.

Regional heterogeneity and driving factors of road runoff pollution from urban areas in China.

Due to the multiple influences of natural and anthropogenic factors, stormwater runoff from urban roads generally presents heterogeneous pollution among cities. The identification of regional heterogeneity and related driving factors of road runoff pollution is of significance for the optimal management of road runoff pollution according to the local circumstances. In this study, the regional heterogeneity of urban road runoff pollution from fourteen representative cities in China is analyzed for four typical pollutants including total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP). The results show wide variations in TSS, COD, TN and TP pollution among cities, with the average event mean concentrations ranging from 77.0 to 1347.9, 31.4 to 488.1, 0.81 to 8.46, 0.139 to 1.930 mg/L, respectively. One-way ANOVA analyses demonstrate significant differences in road runoff pollution among cities. The TSS pollution is significantly heavier for northern and northwestern inland cities than that for eastern and southern cities. Pearson correlation analysis and Stepwise linear regression analysis are performed to identify and rank the influence of climate, population, economy, industry structure, traffic and environmental quality. Direct relationships of road runoff pollution are detected with PM2.5, PM10, secondary industry, tertiary industry, annual rainfall, and urban green coverage, among which PM10 and urban green coverage are the most important and common factors exerting positive and negative influences on road runoff pollution, respectively. Based on the findings of this work, improvement of atmospheric particulate pollution and increase in urban greenness are recommended measures to manage the road runoff pollution. Furthermore, the traffic-related emissions accompanying the upgrading of industry structure should be effectively controlled to attenuate the TSS and COD pollution in road runoff.

Prevalence and risk factors of dementia in elder adults in Xiamen, China: A cross-sectional study.

BACKGROUND: The prevalence of dementia can vary by region and there is a cluster of more than 10 modifiable risk factors for dementia. Therefore, this study aimed to determine the prevalence of dementia in Xiamen, China, and identify independent risk factors associated with dementia. METHODS: This cluster sampling-based cross-sectional study enrolled elder adults from Xiamen City and conducted face-to-face interviews between April and August 2019. Data on the demographic characteristics and prevalence of dementia were collected. Multivariable logistic regression was used to analyse the factors associated with dementia. RESULTS: A total of 6430 subjects were enrolled. The prevalence of dementia was 7.62% (490/6430). A total of 490 patients were in the dementia group and 196 healthy matched subjects were selected for the control group with similar profiles for age, gender, and occupation as the dementia patients. Dementia patients were at increased risk for cerebrovascular disease, traumatic brain injury, and hypertension (all P < 0.05). Multivariable logistic regression analysis showed hypertension (odds ratio (OR) = 2.4, 95% confidence interval (CI): 1.62-3.63, P < 0.001) and traumatic brain injury (OR = 2.19, 95% CI: 1.16-4.53, P = 0.023) were independent risk factors for dementia. CONCLUSIONS: The prevalence of dementia was high among elder adults residing in Xiamen, China. Dementia patients were more likely to have hypertension and traumatic brain injury than the matched control group.

Optimization of technique parameters of pneumatic molding for rice straw bowl tray.

In order to find out the optimized technological parameters of rice straw bowl tray, the forming test was carried out with the slurry made of rice straw as the main raw material and the pneumatic molding machine as the equipment. The orthogonal rotational combination test of ternary quadratic regression and response surface analysis method were used to study the effect of 3 molding factors (vacuum degree, pressure preservation time and adsorption time) on 3 molding technical indices (bowl hole molding rate, relaxation density and rupture-resisting strength). Design-Expert data analysis software was used to establish regression models between rice straw bowl tray molding factors and molding properties so as to obtain optimal technological parameters, which were as follows: vacuum degree: -0.09 MPa; holding time: 14 s; adsorption time: 5 s. At the moment, theoretical bowl hole molding rate was 98.62%, relaxation density was 5.8 g/cm3 and rupture-resisting strength was 27.48 N, the experimental results show that the theoretical analysis is correct, and the model fitting is better. This study can provide a theoretical basis for optimization of pneumatic molding technological of rice straw bowl tray and lay a foundation for realizing industrialized production of biomass seeding tray.

Integrating indices based on different chemical extractions and bioaccumulation in Bellamya aeruginosa to assess metal pollution and ecological risk in sediment.

Various indices based on metal chemical data are used to evaluate pollution and ecological risk, but the consistency of the assessment results is usually unsatisfactory, and it is unclear if the ecological risk from sediment metals is accurately represented in in situ zoobenthos. Herein, the pollution and ecological risk associated with As, Cd, Cr, Cu, Ni, Pb and Zn in the sediments of two adjacent lakes (Datun (DT) and Changqiao (CQ)) were comprehensively evaluated by integrating metal concentrations, chemical forms and bioaccumulation in Bellamya aeruginosa (B. aeruginosa). The metal concentrations and chemical compositions varied widely in the sediments. Over 50% of the Cd, Pb and Zn in the sediments was present in bioavailable forms, followed by 28% of Cu and less than 25% of As, Cr and Ni. According to the enrichment factor (EF) and concentration enrichment ratio (CER) assessments, Cr and Ni were natural in origin, while the other metals were at minor to extremely high pollution levels, with average EFs of 1.5-77.6 and CERs of 1.1-113.4. The pollution levels for Cd, Cu and Pb from the EF and CER assessments were similar, while those for As and Zn were higher according to CER than EF (p = 0.05), likely due to the baseline underestimation associated with the potential diagenetic remobilization of bioavailable metals. The ecological risk index (Er), sediment quality guidelines (SQGs) and risk assessment code (RAC) showed a high eco-risk for Cd, while no similar risk was found for the other metals. By integrating risk indices with the chemical forms and pollution levels of metals, we deduced high eco-risks for As and Pb and moderate eco-risks for Cu and Zn in DT Lake and moderate eco-risks for As, Pb and Zn in CQ Lake. The other metals in the sediments of the two lakes presented low eco-risks. No significant positive correlations (p = 0.05) between metal accumulation in B. aeruginosa and the indices of pollution and eco-risk were observed except for the case of As, implying that measuring the metal concentrations in B. aeruginosa would not accurately characterize the metal pollution and ecological risk of sediments.

Potential to Reduce Chemical Fertilizer Application in Tea Plantations at Various Spatial Scales.

Tea is the main commercial crop grown in China, and excessive application of chemical fertilizers in tea plantations is common. However, the potential to reduce chemical fertilizer use in tea plantations is unclear. In this study, Zhejiang Province was selected as the research object to systematically analyze the potential for tea plantation chemical-fertilizer reduction at different spatial scales. The geographic information system-based analytic hierarchy process method and Soil and Water Assessment Tool model were used to determine the chemical fertilizer reduction potential at the province scale and watershed scale, respectively. At the field scale, two consecutive years of field experiments were conducted on a tea plantation. Province-level analysis showed that 51.7% of the area had an average total fertilization intensity greater than 350 kg/hm2 and a high reduction potential. Watershed analysis revealed that chemical fertilizer reduction had better potential in reducing total nitrogen and total phosphorus inputs to runoff in the short term, whereas 50% organic fertilizer substitution was the best strategy to achieve long-term effects. The field experiments further proved that organic fertilizer substitution balanced tea growth and environmental protection. This study provides a useful method to investigate strategies to reduce chemical fertilizer use in tea-growing areas.

Photocatalytic H2O2 production and removal of Cr (VI) via a novel Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure with broad spectral response.

The low-usage of solar energy and the sluggish separation efficiency of the photogenerated electrons/holes pairs are the obstacles in the practical application of photocatalysts. The integration of upconversion and Z-scheme heterojunction is expected to break the barriers to achieve the efficient charge separation and broaden near-infrared light absorption. Herein, an effective indirect Z scheme AgInS2/In2S3 heterostructure with carbon quantum dots (CQDs, as the electron conduction medium) and Lu3NbO7:Yb, Ho (as upconversion function) has been successfully synthesized. Consequently, the Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure exhibited superior photocatalytic activities for Cr(VI) reduction and H2O2 production, reducing 99.9% of Cr(VI)(20 ppm, 15 min) and 78.5% of Cr(VI) (40 ppm, 30 min) with visible light irradiation as well as 94.0% of Cr(VI) (20 ppm, 39 min) under NIR light irradiation. Simultaneously, the heterostructure could generate 902.9 µM H2O2 for 5 h under visible light irradiation. The intensive photocatalytic properties could primarily be attributed to the boosted light absorption capacity, the improved solar-to-energy conversion by the remarkable upconversion capacity of Lu3NbO7: Yb, Ho/CQDs and the faster charge transfer through a Z-schematic pathway. This work is anticipated to open a novel "window" for designing the efficient photocatalysts by coupling of Lu3NbO7: Yb, Ho and CQDs.

Cd0.5Zn0.5S/CoWO4 Nanohybrids with a Twinning Homojunction and an Interfacial S-Scheme Heterojunction for Efficient Visible-Light-Induced Photocatalytic CO2 Reduction.

The construction of a phase junction photocatalyst can significantly enhance the photocatalytic performance with high selectivity for CO2 reduction. In this study, an S-scheme junction Cd0.5Zn0.5S/CoWO4 semiconductor with the coupling of a twin crystal Cd0.5Zn0.5S homojunction and CoWO4 was designed through a hydrothermal method, which could convert CO2 to CO with high efficiency under visible-light illumination. Cd0.5Zn0.5S-10%CoWO4 exhibited the optimal performance and its CO yield and selectivity were up to 318.68 µmol·g-1 and 95.90%, respectively, which were 4.54 and 1.62 times higher than that of twin crystal Cd0.5Zn0.5S. Moreover, the Cd0.5Zn0.5S homojunction with a zinc-blende and wurtzite phase and the S-scheme phase junction of Cd0.5Zn0.5S/CoWO4 enhanced the property of CO2 adsorption and accelerated the detachment of photogenerated carriers. The combination of photogenerated holes in Cd0.5Zn0.5S and the electrons of CoWO4 can retain the reduction sites to improve photocatalytic performance. This study provides a neoteric concept and reference for the construction of the S-scheme phase junction.

Epidemiology of Frequent/Urgent Urination in Older Adults in China: A Multicenter, Cross-Sectional Study.

Background: Frequent/urgent urination is an event of multifactorial origin where involuntary leakage of urine occurs. Epidemiological study of this condition is of high importance due to its negative impact on the psychological, physical, and social well-being of the victims. Objective: This cross-sectional study aimed to investigate the prevalence of frequent/urgent urination in older adults in China. Method: In this study, a face-to-face questionnaire survey was conducted between April 2019 and August 2019 among 4,796 older adult populations in the communities of Tianjin jizhou and Xiamen jimei of China. Descriptive analysis, univariate regression, and all statistics were conducted in IBM SPSS v22. The count data were analyzed by chi-square test. P < 0.05 was considered statistically significant. Results: In the total investigated population, the prevalence of frequent or urgent urination was found in 1,164 patients (24.3%) where 31.7% (664/2,097) were male patients and 18.7% (500/2,699) were female patients, having a male-to-female ratio of 1.7:1. The prevalence was higher in the 70- to 84-year-old group (men: 33.3-34.8%, women 19.5-20.8%), whereas it was relatively low in the 65- to 69-year-old group and in older adults over 85 years of age (men 28.8, 30.3%, women 16.7, 18.5%, respectively). In terms of the course of the disease, among the population aged 65 years and above, 17.3% men and 9.9% women had frequent urination/urgency lasting for 1-4 years; 5-9 years in about 4.5% population (7.4% men and 4.2% women); 10-19 years in 4.9% men and 2.3% women; and more than 20 years duration in 1.6% men and 1.9% women. On the severity scale, mild frequent/urgent urination was observed in 24.6% of men and 15.4% women of Chinese older adults. Moderate cases were observed in 6.3% of men and 2.9% of women, whereas severe cases were found in 0.8% men and 0.2% women. Benign prostatic hyperplasia (BPH)/hypertrophy was the main risk factor for frequent/urgent urination in Chinese older adult men (P < 0.001). Obesity, hypertension, diabetes, heart disease, anxiety, depression, constipation, and brain injury were the other risk factors for frequent/urgent urination in Chinese older adult men and women. The results of this survey showed that smoking or drinking habits did not increase the prevalence of frequent/urgent urination in Chinese older adults. Conclusions: According to the results of this survey, the prevalence rate of frequent/urgent urination is high, and the course of the disease is long in Chinese older adults. BPH and depression, anxiety, and age-related chronic diseases increase the risk of frequent/urgent urination in Chinese older adults.

Effects of blended versus offline case-centred learning on the academic performance and critical thinking ability of undergraduate nursing students: A cluster randomised controlled trial.

OBJECTIVE: This study aimed to compare the effect of blended and offline case-centred learning on medical nursing education for undergraduate nursing students. BACKGROUND: Technological advancements are rapidly changing nursing education in higher educational settings. Educational reform, especially regarding methods of teaching, has been the focus of nursing educators in recent years. DESIGN: The research was conducted between September 2018 and July 2019 in China. METHODS: Second-year undergraduate nursing students in two classes were enrolled for this study by cluster sampling. The study outcomes were academic performance and critical thinking ability, measured using the Critical Thinking Disposition Inventory-Chinese Version. RESULTS: Students in the experimental class showed significantly higher improvements in academic performance than those in the control class. Compared with the control class, the pre-post difference in competency in critical thinking self-confidence in the experimental class was significantly greater (p = 0.037). In the experimental class, there was a significant improvement over the baseline in the dimension of critical thinking self-confidence (p = 0.022). In the control class, there was a significant improvement over the baseline in the total score (p = 0.029) and two of the seven dimensions: truth-seeking (p = 0.016) and systematicity (p = 0.005). CONCLUSIONS: The use of blended case-centred learning showed promising results in improving students' academic performance. Both blended and offline case-centred learning were indicated to be effective educational approaches to improve the critical thinking ability of undergraduate nursing students and could be implemented for other nursing subjects in the future.

In situ synchrotron diffraction and modeling of non-equilibrium solidification of a MnFeCoNiCu alloy.

The solidification mechanism and segregation behavior of laser-melted Mn35Fe5Co20Ni20Cu20 was firstly investigated via in situ synchrotron x-ray diffraction at millisecond temporal resolution. The transient composition evolution of the random solid solution during sequential solidification of dendritic and interdendritic regions complicates the analysis of synchrotron diffraction data via any single conventional tool, such as Rietveld refinement. Therefore, a novel approach combining a hard-sphere approximation model, thermodynamic simulation, thermal expansion measurement and microstructural characterization was developed to assist in a fundamental understanding of the evolution of local composition, lattice parameter, and dendrite volume fraction corresponding to the diffraction data. This methodology yields self-consistent results across different methods. Via this approach, four distinct stages were identified, including: (I) FCC dendrite solidification, (II) solidification of FCC interdendritic region, (III) solid-state interdiffusion and (IV) final cooling with marginal diffusion. It was found out that in Stage I, Cu and Mn were rejected into liquid as Mn35Fe5Co20Ni20Cu20 solidified dendritically. During Stage II, the lattice parameter disparity between dendrite and interdendritic region escalated as Cu and Mn continued segregating into the interdendritic region. After complete solidification, during Stage III, the lattice parameter disparity gradually decreases, demonstrating a degree of composition homogenization. The volume fraction of dendrites slightly grew from 58.3 to 65.5%, based on the evolving composition profile across a dendrite/interdendritic interface in diffusion calculations. Postmortem metallography further confirmed that dendrites have a volume fraction of 64.7% ± 5.3% in the final microstructure.

Organic fertilizer reduced carbon and nitrogen in runoff and buffered soil acidification in tea plantations: Evidence in nutrient contents and isotope fractionations.

Carbon (C) and nitrogen (N) inputs to farmland via fertilizer application are potential sources of C and N that influence soil acidification and water eutrophication. A pilot study was conducted to compare the effects of compound fertilizer and rapeseed cake organic fertilizer on C and N preservation in the soils and runoff of a tea plantation as well as the C and N isotopic fractionation in soils over the three annual cycles of fertilization and tea-leaf harvest. Overall, rapeseed cake organic fertilization effectively increased the pH, total organic matter, NH4-N and NO3-N in soils by 2.19-4.29%, 8.04-21.14%, 53.65-100.32% and 5.74-54.08%, respectively, but decreased NH4-N inputs in runoff by 10.36-25.12% and NO3-N inputs in runoff by 8.94-24.10% relative to the same rate of pure N in compound fertilizer. Before fertilization in February, the average δ13C and δ15N were -25.15‰ and 1.88‰, while after a full year of fertilization and tea-leaf harvesting in October, the average soil δ13C and δ15N contents were -23.83‰ and -0.33‰ after compound fertilization and -26.22‰ and 1.64‰ after rapeseed cake organic fertilization, respectively, indicating the evident effects of fertilization on the isotopic fractionation in soil. In addition, the fractionation extent was positively associated with the fertilization rates under both fertilizers. However, the two fertilization types had different effects on the C and N isotope fractionations, with rapeseed cake organic fertilization contributing more to δ13C (21.07-81.80%) but less to δ15N (18.20-78.93%) and compound fertilization presenting the opposite results (1.88-46.18% and 53.82-98.12%, respectively). This study demonstrates that rapeseed cake organic fertilization can better preserve soil C and N pools while reducing their runoff in tea plantations, which may greatly hinder the regional soil acidification and water eutrophication trends.

Comprehensive assessment of heavy metal pollution and ecological risk in lake sediment by combining total concentration and chemical partitioning.

Total concentration and chemical partitioning of heavy metals are commonly used in environmental quality assessment; however, their comparability and comprehensive application are far less discussed. Herein, bioavailability, pollution and eco-risk of As, Cd, Cr, Cu, Ni, Pb and Zn in surface sediments of Erhai Lake were evaluated referring to multiple indices following the experimental methods of complete digestion, optimized Community Bureau of Reference (BCR) and 1.0 M HCl extractions. Results of bioavailability for most metals were similar and comparable from BCR and HCl extractions. While bioavailable concentrations of Cd and Pb from HCl extraction were significantly (p < 0.01) lower than those from BCR extraction, indicating BCR extraction is more efficient. Results of enrichment factor (EF) and concentration enrichment ratio (CER) suggested that Cd was the highest polluted element followed by As, Pb and Zn, whereas Cr, Cu and Ni were mainly natural in origin. Similar concentrations of anthropogenic As from EF and CER assessments indicated anthropogenic As mainly existed in bioavailable form. However, anthropogenic Cd, Pb and Zn existed in both bioavailable and residue forms, resulting in the underestimation of anthropogenic metals by the CER assessment. The sediment quality guidelines (SQGs), potential ecological risk index (Er) and risk assessment code (RAC) showed inconsistent eco-risks for each of the metals except Cd. Combining pollution level and chemical partitioning with SQGs, Er and RAC assessments, high eco-risk of Cd, moderate eco-risk of As and Pb, and low eco-risk of Cr, Cu, Ni and Zn were graded. Our study highlights the limitation of single index and the necessity of integrating multiple indices following total concentration and chemical partitioning in metal pollution and eco-risk assessments.

Effect of Different Combinations of Phosphorus and Nitrogen Fertilization on Arbuscular Mycorrhizal Fungi and Aphids in Wheat.

While chemical fertilizers can be used to increase crop yield, the abuse of fertilizers aggravates environmental pollution and soil degradation. Understanding the effects of chemical fertilizers on the interaction between arbuscular mycorrhizal fungi (AMF) and pest insects is of great benefit to crop and environmental protection, because AMF can enhance the nutrition absorption and insect resistance of crops. This study tested the effect of different levels of phosphorus, nitrogen, and their interactions on AMF, secondary metabolites, Sitobion avenae in garden, as well as the wheat traits in field. The results showed that AMF colonization on roots in the P0N1 treatment (0 g P/pot, 1.3083 g N/pot in the garden, and 0 g P/plot, 299.84 g N/plot) was the highest in both the garden and the field. The abundance of aphid was reduced in the P0N1 treatment, and there were negative relationships between aphids and AMF and phenolics, but a positive relationship between AMF and phenolics. Our results indicated that a change in the ratio of phosphorus to nitrogen affects the relationship among AMF, aphid abundance, and metabolites. The results also suggested an approach to save chemical fertilizers that could improve crop health and protect the agroecosystem against pollution at the same time.

Application of stable isotopes to the bioaccumulation and trophic transfer of arsenic in aquatic organisms around a closed realgar mine.

The bioaccumulation and trophic transfer of As along food webs in freshwater ecosystems remain largely unknown. In this study, multiple environmental and biological samples were collected from a closed realgar mining area in South China. The As concentrations in the surface water, sediments and soils in the mining area were 0.62-3293 µg/L, 9.53-4543 mg/kg and 7.32-5008 mg/kg, respectively, and gradually decreased with distance from the central mining sites, indicating that historic As mining activities had an eminent impact on As contamination around the mine. The As concentrations in aquatic organisms ranged from 0.60 mg/kg to 45.75 mg/kg and varied markedly among sites and species, reflecting the influence of various physiologic and environmental factors. Arsenic species identified by liquid chromatography inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) were mainly organic, comprising 8% to 66% of the total As. Both the proportions and concentrations of inorganic As were positively correlated with total As. This correlation could be attributed to the higher assimilation and accumulation of inorganic As or the lower biotransformation ability of inorganic As with the increasing total As in the studied organisms. Values of δ13C and δ15N in aquatic organisms ranged from -30.59‰ to -15.07‰ and from 4.31‰ to 12.98‰, respectively, indicating multiple trophic levels and variety in the diet sources of these organisms. The δ15N increased distinctly in the order of planktivorous

Spatio-temporal variations of sedimentary metals in a large suburban lake in southwest China and the implications for anthropogenic processes.

Environment quality of suburban and urban lakes receives special attention due to their great impacted by human perturbations and important roles in ecosystem services. Herein, the spatio-temporal variations of 10 metal and metalloid elements in 13 sediment cores from a large suburban lake (Dianchi) were studied to explore the changes in sedimentary environment and pollution and their associations with human activities since the last century. Concentrations of each element were largely varied at spatial scales, but showed similar vertical trends among the profiles, suggesting comparable changes in sedimentary processes in each lake region. Cluster analysis showed two groups of elements: group I includes Al, Ti, Cu, Cr and Ni, and group II includes As, Cd, Hg, Pb and Zn. Temporally, concentrations of all elements were generally constant until the 1950s. Thereafter, group I elements along with the clay percentage started to decrease, indicating accelerated input of coarser soils due to strengthening human perturbation and changing land use. However, group II elements showed increasing values of concentrations, particularly the enrichment factors (EF = 1.0-10.8), which peaked between mid-1990s and 2000, indicating continued pollutants input with watershed economic development. With the implementation of environment management measures, pollution was initially restrained or reduced in recent decades as indicated by the stable EFs and sedimentary fluxes of Cd, Hg, Pb and Zn and decreasing values of As. Spatially, the stocks of anthropogenic As, Cd, Hg, Pb and Zn were higher in the northern while lower in the southern lake area. This spatial difference was mainly due to the large input of industrial and domestic wastewaters in the northern compared to the area in the southern that receives runoff from agricultural and forested land. Overall, the spatio-temporal patterns in accumulation of metal and metalloid elements in the lake reliably reflected the impacts of watershed human activities.