The disease recurrence perception scale for patients with inflammatory bowel disease: Instrument development and cross-sectional validation study.

Disease recurrence perception plays a key role in disease management and subsequent disease recurrence prevention. However, there are no specific tools for assessing disease recurrence perception in patients with inflammatory bowel disease (IBD) characterized by alternating remission and recurrence. To develop and validate an instrument for measuring disease recurrence perception of patients with IBD, the study was conducted in two steps: (1) instrument development and (2) psychometric tests. A total of 623 patients with IBD participated in the study. The common sense model of illness self-regulation (CSM) was used as a framework for instrument development. The administered version contained 48 items intended to be relevant to at least one of the six dimensions of the model. Based on preliminary analyzes, 12 items were deleted leaving 36 items for more detailed psychometric and factor analyzes. The Cronbach's alpha coefficient of the total 36-item instrument was 0.915. The content validity indexes at item and scale levels were satisfactory. The test-retest reliability of the total instrument was 0.870. Exploratory principal components analysis (n = 278) was used to identify six components congruent with intended CSM constructs that accounted for 62.6% of total item variance. Confirmatory factor analysis (n = 345) found acceptable fit for the six factor measurement model (χ2/df = 1.999, GFI = 0.846, NFI = 0.855, IFI = 0.922, TLI = 0.910, CFI = 0.921, RMSEA = 0.054). Overall, the DRPSIBD demonstrated satisfactory reliability and validity to warrant further development as a measure of disease recurrence perception of patients with IBD.

The impact of social support on benefit finding among patients with advanced lung cancer and their caregivers: based on actor-partner interdependence mediation model.

PURPOSE: Advanced lung cancer and its treatment serve as a sudden stressful event that profoundly impacts the psychological experience of both the patients and their primary caregiver. This study used dyadic analyses to explore the dyadic effects of social support on benefit finding and whether hope level mediates the patient-caregiver dyads in advanced lung cancer. METHODS: Two hundred ninety-five pairs of patients with advanced lung cancer and primary caregivers completed the Social Support Rating Scale (SSRS), the Herth Hope Index (HHI), and the Benefit Finding Scale (BFS). Dyadic analyses were conducted using structural equation modelling based on the actor-partner interdependence mediation model. RESULTS: The results indicated that for both patients (B = 0.259, 95% CI = 0.135-0.423, P < 0.001) and their primary caregivers (B = 0.596, 95% CI = 0.403-0.838, P < 0.001), hope level mediated the actor effect of social support on benefit finding; social support was positively associated with hope level and further enhanced benefit finding. Regarding partner effects (B = 0.242, 95% CI = 0.119-0.404, P < 0.001), primary caregivers' social support significantly indirectly affected patients' benefit finding through patients' hope level. CONCLUSION: There is an interaction between social support, hope level, and benefit finding in patients with advanced lung cancer and their primary caregivers. Healthcare professionals ought to be vigilant in recognizing patients and caregivers who are vulnerable, have limited social support, and possess diminished hope levels. At the same time, nurses should provide timely psychological support and counseling to patients and their caregivers, encourage them to actively participate in social activities, and inspire their confidence and hope in life, thus improving their benefit findings.

Type 2 diabetes and inflammatory bowel disease: a bidirectional two-sample Mendelian randomization study.

To investigate the association between T2DM and IBD by bidirectional two-sample Mendelian randomization (MR) to clarify the casual relationship. Independent genetic variants for T2DM and IBD were selected as instruments from published genome-wide association studies (GWAS), mainly in European ancestry. Instrumental variables (IVs) associated with T2DM and IBD were extracted separately from the largest GWAS meta-analysis. MR analyses included inverse variance weighting, weighted median estimator, MR Egger regression, and sensitivity analyses with Steiger filtering and MR PRESSO. In the data samples for Ulcerative colitis (UC) (6968 cases, 20,464 controls) and Crohn's disease (CD) (5956 cases, 14,927 controls), there was a negative causal relationship between T2DM and UC [IVW, OR/95%CI: 0.882/(0.826,0.942), p < 0.001]. However, the causal relationships between T2DM and CD, UC and T2DM, CD and T2DM were not significant, and the p value measured by the IVW method was ≥ 0.05. All SNPs showed no significant horizontal pleiotropy (p > 0.05). The results of the bidirectional MR Study suggest that T2DM has a negative causal effect on UC, which provides implications for clinical treatment decisions in IBD patients with T2DM. The findings do not support a causal relationship between T2DM and CD, UC and T2DM, or CD and T2DM, and the impact of IBD on T2DM needs further investigation.

Heterogeneity in Psychological Adaptation Patterns and Its Predictive Factors Among Patients with Inflammatory Bowel Disease: A Latent Profile Analysis.

Purpose: To identify the distinct profiles of psychosocial adaptation of Chinese inflammatory bowel disease (IBD) patients and the predictive factors. Patients and Methods: A cross-sectional survey method was used to recruit 263 IBD patients who were treated in a tertiary hospital in Shandong Province from July 2022 to April 2023. The general information questionnaire, Inflammatory Bowel Disease Psychosocial Adaptation Questionnaire, Resilience Scale for Inflammatory Bowel Disease, Chinese Benefit Finding Scale, and Stigma Scale for Chronic Illnesses, Medical Coping Modes Questionnaire and Inflammatory Bowel Disease-Disk were used as the instruments for investigation. Latent profile analysis was conducted with the six dimensions of the IBD Psychosocial Adaptation Questionnaire as the explicit indicators. The predictors of profile membership were analyzed by multinomial logistic regressions. Results: Four profiles of psychosocial adaptation in IBD patients were identified: Low level psychosocial adaptation (14.1%), Medium level psychosocial adaptation - High body image distress (25.5%), Medium level psychosocial adaptation - Low body image distress (30.0%) and High level psychosocial adaptation (30.4%). Compared with Low level psychosocial adaptation group, High level psychosocial adaptation group had a higher level of positive cognition (OR=2.930, 95%IC 0.017-0.305, p< 0.001) and overall psychological resilience (OR=1.832, 95%IC 0.000-0.016, p < 0.001), more health behaviors (OR= 2.520, 95%IC 0.191-1.358, p=0.001), a lower level of internal stigma (OR=0.135, 95%IC 0.043-0.420, p < 0.001) and overall stigma (OR=0.010, 95%IC 0.003-0.118, p=0.001), less acceptance-resignation coping style (OR=0.055, 95%IC 0.209-3.200, p < 0.001) and lower disease burden (OR=0.407, 95%IC 0.298-0.698, p=0.006). Conclusion: About a half of IBD patients had a medium level of psychosocial adaptation. Psychological resilience, benefit finding, stigma, medical coping styles and disease burden predicted psychosocial adaptation profiles. Healthcare providers need to focus on the heterogeneity of psychosocial adaptation of IBD patients and formulate personalized intervention programs for patients with different profiles to improve their psychosocial adaptation.

Development of Single-Segment Substitution Lines and Fine-Mapping of qSPP4 for Spikelets Per Panicle and qGW9 for Grain Width Based on Rice Dual-Segment Substitution Line Z783.

Single segment substitution line (SSSL) libraries are an ideal platform for breeding by design. To develop SSSLs-Xihui18 covering the whole genome, a novel rice chromosome segment substitution line (CSSL), Z783, carrying two substitution segments (average length of 6.55 Mb) on Chr.4 and Chr.9 was identified, which was a gap in the library previously. Z783 was developed from the progeny of recipient "Xihui18" (an indica restorer line) and donor "Huhan3" (a japonica cultivar) by advanced backcross combined molecular marker-assisted selection (MAS). It displayed multiple panicles and less spikelets and wide grains. Then, a F2 population derived from Xihui18/Z783 was used to map quantitative trait loci (QTLs) for yield-related traits by the mixed linear model method. Nine QTLs were detected (p < 0.05). Furthermore, three SSSLs were constructed by MAS, and all 9 QTLs could be validated, and 15 novel QTLs could be detected by these SSSLs by a one-way ANOVA analysis. The genetic analysis showed that qSSP4 for less spikelets and qGW9 for wide grain all displayed dominant gene action in their SSSLs. Finally, qSSP4 and qGW9 were fine-mapped to intervals of 2.75 Mb and 1.84 Mb, on Chromosomes 4 and 9, respectively. The results lay a solid foundation for their map cloning and molecular breeding by design.

The Mediating Effect of Hope Level Between Social Support and Benefit Finding in Patients With Advanced Lung Cancer.

BACKGROUND: As a protective factor, social support can influence benefit finding (BF) in patients with advanced lung cancer. However, the mechanism through which social support affects BF is controversial. OBJECTIVE: To investigate the factors influencing BF in patients with advanced lung cancer and the role of hope level in mediating the relationship between social support and BF. METHODS: This was a cross-sectional study. From September 2022 to March 2023, 286 participants completed the Social Support Rating Scale, Herth Hope Index, and Benefit Finding Scale. Data analysis included correlation analyses and multiple stepwise regression analysis; the SPSS PROCESS program was used to determine the significance of mediating effects. RESULTS: Social support and hope level were positively associated with BF. Monthly per-capita household income, social support and hope level entered the final regression model and explained 50.7% of BF variance. Social support's direct and indirect effects on BF were significant (P < .05), suggesting that hope level partially mediated the relationship between social support and BF. CONCLUSION: Our findings validate a positive association between social support and BF in patients with advanced lung cancer. The hope level as a mediating variable provided the impetus for their BF. IMPLICATIONS FOR PRACTICE: Nurses should implement necessary interventions to help patients with advanced lung cancer carry out protective resources and coping strategies to facilitate their BF.

Genetic Effects Analysis of QTLs for Rice Grain Size Based on CSSL-Z403 and Its Dissected Single and Dual-Segment Substitution Lines.

Rice chromosomal segment substitution lines (CSSLs) are ideal materials for studying quantitative traits such as grain size. Here, a rice large-grain CSSL-Z403 was identified among progeny of the recipient Xihui18 and the donor Jinhui35 based on molecular marker-assisted selection. Z403 carried 10 substitution segments with average length of 3.01 Mb. Then, a secondary F2 population derived from a cross between Xihui18 and Z403 was used to map quantitative trait loci (QTL) for grain size. Six QTLs distributed on chromosomes 5, 6, 7, 9 and 12 were detected. Finally four single-segment substitution lines (SSSLs) and two dual-segment substitution lines (DSSLs) carrying these target QTLs were constructed, and 10 novel QTLs were identified by four SSSLs. The large grain of Z403 was controlled at least by qGWT5, qGWT7, qGWT9 and qGWT12, and its grain weight was influenced through grain length QTL such as qGL5, qGL6, qGL9 and qGL12, as well as grain width QTL such as qGW5, qGW7, qGW9 and qGW12. Among 16 QTLs, four QTLs including qGL6, etc., might be novel compared with the reported documents. Again, positive or less negative epistatic effects between two non-allelic QTLs (additive effect > 0) may assist screening the genotype with larger grain size in further selection.

The Association between Self-Rated Health and Health Self-Management Ability of Healthcare Undergraduates: The Chain Mediating Roles of eHealth Literacy and Resistance to Peer Influence.

Health self-management is important for healthcare undergraduates who are at the late adolescent or early adulthood stage, and will play an important part in health promotion for the general population. Previous research has shown that perceived health status affects health self-management. However, few studies have uncovered the mechanism between self-rated health and health self-management among healthcare undergraduates. Based on social ecology theory and Pender's health promotion model, this study aimed to explore the associations between health self-management ability, self-rated health, eHealth literacy and resistance to peer influence of healthcare undergraduates, with a focus on identifying the mediating effects of eHealth literacy and resistance to peer influence. A cross-sectional study was conducted among 515 healthcare undergraduates in Eastern China between July and September 2021. Serial mediation analysis was performed using Haye's Model 6 PROCESS macro to examine the mediating effects. The study found that health self-management ability was significantly and positively correlated with eHealth literacy, resistance to peer influence and self-rated health. Self-rated health had a direct and positive predictive effect on health self-management, with a direct effect value of 0.654. eHealth literacy and resistance to peer influence played both an independent mediating and a chain-mediating role in the mechanism of self-rated health affecting health self-management among healthcare undergraduates, with indirect effect values of 0.085, 0.101, and 0.013, respectively. The results suggest that eHealth literacy and resistance to peer influence could be intervention targets in programs for improving these students' health self-management ability.

Psychosocial Adaptation Among Inflammatory Bowel Disease Patients and Associated Factors: A Cross-Sectional Study.

Purpose: Patients with inflammatory bowel disease (IBD) suffer from physical symptoms and psychosocial issues. This generates risks of psychosocial maladjustment that is closely linked with self-care ability and health-related quality of life. The study aimed to explore psychosocial adaptation of IBD patients in China and the influencing factors from individual and family levels. Patients and Methods: Using a cross-sectional design, 191 Chinese patients with IBD were recruited from October 2020 to September 2021. General information questionnaire, general family functioning scale, resilience scale for IBD, and psychosocial adaptation questionnaire for IBD were used for investigation. Multivariate linear regression was used to identify predictive factors of psychosocial adaptation. Results: IBD patients reported a moderate level of psychosocial adaptation. Regression analysis showed that personal resilience especially the three dimensions (i.e., positive illness perception, disease management, and support from fellow IBD patients), general family functioning, and disease conditions (i.e., extra-intestinal manifestations and current disease status) were the main contributing factors of psychosocial adaptation, explaining 49.3% of the total variance. Conclusion: The findings suggest that healthcare providers could focus on improving patients' illness perception about IBD and strengthening their disease management abilities, together with optimizing patients' family functioning to enhance their psychosocial adaptation level.

Excess and Defect: How Job-Family Responsibilities Congruence Effect the Employee Procrastination Behavior.

Purpose: Prior work suggests that responsibility is negatively associated with employee procrastination behavior. Based on the conservation of resources (COR) theory, we suggest this view is oversimplified and propose that procrastination can be induced when employees have congruent job and family responsibilities via the mediating effect of emotional exhaustion. Methods: This is a quantitative study of the configurational approach. Survey data were collected from 323 employees at two stages in southern Chinese internet enterprises in September 2020. A randomized cluster sample was used and an anonymous self-assessment questionnaire was distributed to all selected respondents (employees). Samples involved different departments, and the procrastination phenomenon is more significant among them. SPSS20.2 and MPLUS 8.3 software and Response Surface Analysis Strategy were used to test the hypotheses. Results: The data analysis results indicated that: a) employee procrastination behavior is higher when employees' job responsibility and family responsibility are congruent than the incongruent configurations. b) Procrastination is lower when job-family dyads are congruent at high levels of responsibility compared the low levels. c) Procrastination decreases as employees' job and family responsibilities become more discrepant (ie, incongruent); employees with low job-high family responsibilities procrastinate more than those with high job-low family responsibilities. d) Additionally, employee-experienced emotional exhaustion mediates the relationship in four configurations between job-family responsibilities congruence and procrastination behavior. Conclusion: Drawing on the conservation of resources theory, we proposed a model clarifying how varying combinations of job and family responsibilities affect employee procrastination behavior. The results showed that there are significant differences in the impact of different job-family responsibility combinations on employee procrastination behavior. Employee procrastination behavior is higher when employees' job-family responsibility are congruent than the incongruent configurations. Additionally, employee-experienced emotional exhaustion mediates the relationship in four configurations between job-family responsibilities congruence and procrastination behavior.

QTL Analysis of Z414, a Chromosome Segment Substitution Line with Short, Wide Grains, and Substitution Mapping of qGL11 in Rice.

Most agronomic traits of rice (Oryza sativa), such as grain length, are complex traits controlled by multiple genes. Chromosome segment substitution lines (CSSLs) are ideal materials for dissecting these complex traits. We developed the novel rice CSSL 'Z414', which has short, wide grains, from progeny of the recipient parent 'Xihui 18' (an indica restorer line) and the donor parent 'Huhan 3' (a japonica cultivar). Z414 contains four substitution segments with an average length of 3.04 Mb. Z414 displays seven traits that significantly differ from those of Xihui 18, including differences in grain length, width, and weight; degree of chalkiness; and brown rice rate. We identified seven quantitative trait loci (QTL) that are responsible for these differences in an F2 population from a cross between Xihui 18 and Z414. Among these, six QTL (qPL3, qGW5, qGL11, qRLW5, qRLW11, and qGWT5) were detected in newly developed single-segment substitution lines (SSSLs) S1-S6. In addition, four QTL (qGL3, qGL5, qCD3, and qCD5) were detected in S1 and S5. Analysis of these SSSLs attributed the short, wide grain trait of Z414 to qGL11, qGL3, qGL5, and qGW5. Substitution mapping delimited qGL11 within an 810-kb interval on chromosome 11. Sequencing, real time quantitative PCR, and cell morphology analysis revealed that qGL11 might be a novel QTL encoding the cyclin CycT1;3. Finally, pyramiding qGL3 (a = 0.43) and qGL11 (a = - 0.37) led to shorter grains in the dual-segment substitution line D2 and revealed that qGL11 is epistatic to qGL3. In addition, S1 and D2 exhibited different grain sizes and less chalkiness than Z414. In conclusion, the short grain phenotype of the CSSL Z414 is controlled by qGL11, qGL3, and qGL5. qGL11 might be a novel QTL encoding CycT1;3, whose specific role in regulating grain length was previously unknown, and qGL11 is epistatic to qGL3. S1 and D2 could potentially be used in hybrid rice breeding.

Coping with job stress for hospital nurses during the COVID-19 crisis: The joint roles of micro-breaks and psychological detachment.

AIM: To examine a mediated moderation of the effects of micro-break activity and psychological detachment on the relationship between job stress and work engagement among hospital nurses. BACKGROUND: Nursing burnout, compassion fatigue and job stress have been relatively constant issues in nursing for at least the past decade-and the pervasiveness of the COVID-19 pandemic is intensifying them, which may lead to new challenges to work engagement. METHODS: We tested our model using a time-lagged design to collect data from supervisor-subordinate dyads in seven public hospitals located in southern China, and 263 nurses and 58 head nurses in this survey. Confirmatory factor analysis, Pearson's correlation and hierarchical multiple regression were carried out. RESULTS: The results showed that the adverse impact of job stress on work engagement disappeared when nurses engaged in high levels of micro-break activity. Moreover, the moderating role of micro-break activity was mediated by psychological detachment. CONCLUSIONS: Micro-break activity and psychological detachment play joint roles in helping nurses to cope with job stress. IMPLICATIONS FOR NURSING MANAGEMENT: Nurse managers should change their negative attitude toward micro-break activity (if it exists) and help nurses find opportunities for detachment under high-pressure environment.

Substantial nitrogen oxides emission reduction from China due to COVID-19 and its impact on surface ozone and aerosol pollution.

A top-down approach was employed to estimate the influence of lockdown measures implemented during the COVID-19 pandemic on NOx emissions and subsequent influence on surface PM2.5 and ozone in China. The nation-wide NOx emission reduction of 53.4% due to the lockdown in 2020 quarter one in China may represent the current upper limit of China's NOx emission control. During the Chinese New Year Holiday (P2), NOx emission intensity in China declined by 44.7% compared to the preceding 3 weeks (P1). NOx emission intensity increased by 20.3% during the 4 weeks after P2 (P3), despite the unchanged NO2 column. It recovered to 2019 level at the end of March (P4). The East China (22°N - 42°N, 102°E - 122°E) received greater influence from COVID-19. Overall NOx emission from East China for 2020 first quarter is 40.5% lower than 2019, and in P4 it is still 22.9% below the same period in 2019. The 40.5% decrease of NOx emission in 2020 first quarter in East China lead to 36.5% increase of surface O3 and 12.5% decrease of surface PM2.5. The elevated O3 promotes the secondary aerosol formation through heterogeneous pathways. We recommend that the complicated interaction between PM2.5 and O3 should be considered in the emission control strategy making process in the future.

How Servant Leadership Motivates Innovative Behavior: A Moderated Mediation Model.

Drawing on social identity theory, this study examines the effect of servant leadership on university teachers' innovative behavior through the self-concept constructs of perceived insider status and organization-based self-esteem, and the moderating effect of leader-member exchange (LMX). This moderated mediation model was tested with two waves of data from 269 university teachers in China. Results reveal that the self-concept constructs mediate the relationship between servant leadership and university teachers' innovative behavior. Moreover, LMX strengthens the relationship between servant leadership and the self-concept constructs, as well as the indirect effect of servant leadership on university teachers' innovative behavior through the self-concept constructs. Findings suggest that servant leadership is related to increased innovative behavior due to its positive influence on the self-concept of university teachers and it highlights the importance of developing a favorable supervisor-subordinate relationship.

On-road emission measurements of reactive nitrogen compounds from heavy-duty diesel trucks in China.

Emissions of major reactive nitrogen compounds, including nitric oxide (NO), nitrogen dioxide (NO2) and ammonia (NH3), from heavy-duty diesel vehicles (HDDVs) place substantial pressure on air quality for many large cities in China. To control nitrogen oxide (NOX) emissions from HDDVs, selective catalytic reduction (SCR) systems have been widely used since the China IV standards. To investigate the impacts of aftertreatment technologies and driving conditions on real-world emissions of reactive nitrogen compounds, a portable emissions measurement system was employed to test eighteen heavy-duty diesel trucks in China. The results showed that the China IV and China V HDDVs with appropriate SCR functionality could reduce NOX emissions by 36% and 53%, respectively, compared to the China III results, although their real-world emissions were still higher than the corresponding emission limits for regulatory engine tests. For these HDDVs, five samples were tested with NH3 emissions, ranging from 1.67 ppm to 51.49 ppm. The NH3 emission rates tended to significantly increase under high-speed driving conditions. The results indicate that the current SCR technology may have certain risks in exceeding the future China VI NH3 limit. However, five China IV/V HDDVs were found to have SCR temperature sensors that were intentionally tampered with, resulting in comparable or even higher NOX emissions and zero NH3 emissions. Increased NO2 emissions due to the adoption of diesel oxidation catalysts and diesel particulate filters were also found from our experiments. This study highlights the importance of enhancing in-use compliance requirements and eliminating aftertreatment tampering for China IV and China V HDDVs.

Subtropical Forests Act as Mercury Sinks but as Net Sources of Gaseous Elemental Mercury in South China.

Comprehensive mercury (Hg) budgets were constructed in two typical subtropical forests in southern China in 2014 to quantify Hg (gaseous elemental Hg, Hg0, and reactive Hg, HgII) input and output fluxes and Hg retention in forests, consequently exploring the roles of subtropical forests in the global Hg cycle. At site Qianyanzhou, representing a background region with an enhanced atmospheric Hg0 concentration, the total HgII deposition (67.7 µg·m-2·year-1, 73% as dry HgII deposition) was found to be slightly higher than the Hg0 emission above the canopy (58.5 µg·m-2·year-1), indicating that the forest is a minor Hg sink but a significant net Hg0 source on a yearly basis. In contrast, the forest in the moderately polluted region (site Huitong) acted as a significant Hg sink but a minor net Hg0 source with a higher HgII deposition (73.7 µg·m-2·year-1) and relatively negligible Hg0 emission (2.65 µg·m-2·year-1). The decreasing atmospheric Hg0 concentrations declined the total Hg sink based on the Hg budgets synthesized of this and previous studies and may promote forest Hg0 emissions. Consequently, it was expected that the re-emission of historically deposited Hg may be enhanced from subtropical forests by recent decreases in atmospheric Hg0 concentrations throughout China.

Ethical Leadership and Young University Teachers' Work Engagement: A Moderated Mediation Model.

This paper aims to examine the mediating role of organizational trust in the relationship between ethical leadership and young teachers' work engagement, and the moderating effect of supervisor-subordinate (S-S) guanxi. S-S guanxi is a special interpersonal relationship in Chinese organizations. The sample in this study comprises 205 young teachers from 15 Chinese universities. The results reveal that organizational trust mediates the relationship between ethical leadership and young teachers' work engagement. Moreover, S-S guanxi strengthens the positive relationship between organizational trust and young teachers' work engagement, and the indirect effect of ethical leadership on young teachers' work engagement through organizational trust. Based upon these findings, several theoretical and practical implications are discussed.

The decay of silver nanoparticles in preoxidation process.

To investigate the fate of metal-based nanoparticles in water oxidation treatment processes, the decay of Ag-NPs in the presence of three kinds of water treatment preoxidants, sodium hypochlorite (NaClO), hydrogen peroxide (H2O2) and potassium permanganate (KMnO4), was investigated in this work. Dissolution of Ag-NPs into silver ions (Ag+) was found to occur under exposure to NaClO, H2O2 and KMnO4. The morphology of Ag-NPs changed after reacting with NaClO, H2O2 and KMnO4. Factors affecting the decay of Ag-NPs, i.e., the dosage of oxidants, pH, the presence of humic acid, typical ions in water, and the size of the nanoparticles, were investigated. A higher dosage of oxidants, the presence of calcium ions, and lower size of Ag-NPs promoted the decay of Ag-NPs. The presence of humic acid and sulfide ions inhibited the decay of Ag-NPs. The decay of Ag-NPs under exposure to oxidants was significantly affected by the pH. The mechanism of the Ag-NPs in the presence of oxidants under different environmental conditions is also discussed.

Inhibition of mercury release from forest soil by high atmospheric deposition of Ca²âº and SO4²â».

As one of the most important natural mercury (Hg) sources, soil release (emission to the atmosphere or leaching to soil water) depends on various factors, some of which can be affected by atmospheric deposition. We studied the effect of flue gas desulfurization gypsum (FGDG) addition on soil Hg release in a Masson pine (Pinus massoniana) forest in southwestern China. FGDG addition simulated atmospheric deposition of Ca(2+), SO4(2-) and Hg, which are commonly high in China. Results showed that Hg concentration in soil water decreased with the gypsum treatment, suggesting that the mobility of Hg in mineral soil was reduced. Moreover, the application of gypsum also seems to have decreased Hg emission from the soil, shown by the lower Hg contents in leaf tissues of ground vegetation in the treated plots than in the reference. Both Hg mobility in the soil and Hg emission to the atmosphere were decreased despite the additional Hg input from FGDG. The decreased DOC concentration in soil water and the elevated organic sulfur content in the soil Oe & Oa horizons were speculated to result in an enhanced capacity of surface soil to bind Hg, and thus to reduce Hg release from the soil. However, with the increasingly stringent control of particulate matter (PM) and sulfur dioxide (SO2) emissions in China, the deposition of Ca(2+) and SO4(2-) is expected to decrease, and their ability to inhibit soil Hg release is likely to decline in the future.

Mercury concentrations in forest soils and stream waters in northeast and south China.

Atmospheric deposition of mercury (Hg) is generally higher in China than in North America and Europe. Transport and methylation of Hg deposited in forest ecosystems may cause health risks to humans. We collected water samples from 117 small streams, and soil samples from 25 sites in forested areas in northeast and south China during 2011-2013 to investigate the spatial distribution of Hg. Results showed that Hg concentration in surface soil (0-5 cm in depth) was generally higher in south China (97.8 ± 36.0 µg/kg) than that in the northeast (44.0 ± 14.1 µg/kg). In contrast, the Hg concentration in stream water was higher in northeast China (17.2 ± 11.0 ng/L) than that in the south (6.2 ± 6.4 ng/L). Hg concentrations in surface soil were positively correlated with Hg concentrations in the overlying litter Oe/Oa horizon (r(2)=0.84). Hg concentrations in stream water were positively correlated to DOC (dissolved organic carbon) concentrations (r(2)=0.43) and to the Hg concentration in the litter Oe/Oa horizon (r(2)=0.69). Because the litter Oe/Oa horizon represents Hg accumulated by foliage, the positive correlations indicate that atmospheric Hg deposition was an important factor affecting Hg concentrations in soils and stream water.