Data-Independent Acquisition-Based Quantitative Proteomic Analysis Reveals Potential Salivary Biomarkers of Primary Sjögren's Syndrome.

Objective As primary Sj?gren's syndrome (pSS) primarily affects the salivary glands, saliva can serve as an indicator of the glands' pathophysiology and the disease's status. This study aims to illustrate the salivary proteomic profiles of pSS patients and identify potential candidate biomarkers for diagnosis.Methods The discovery set contained 49 samples (24 from pSS and 25 from age- and gender-matched healthy controls [HCs]) and the validation set included 25 samples (12 from pSS and 13 from HCs). Totally 36 pSS patients and 38 HCs were centrally randomized into the discovery set or to the validation set at a 2:1 ratio. Unstimulated whole saliva samples from pSS patients and HCs were analyzed using a data-independent acquisition (DIA) strategy on a 2D LC?HRMS/MS platform to reveal differential proteins. The crucial proteins were verified using DIA analysis and annotated using gene ontology (GO) and International Pharmaceutical Abstracts (IPA) analysis. A prediction model for SS was established using random forests.Results A total of 1,963 proteins were discovered, and 136 proteins exhibited differential representation in pSS patients. The bioinformatic research indicated that these proteins were primarily linked to immunological functions, metabolism, and inflammation. A panel of 19 protein biomarkers was identified by ranking order based on P-value and random forest algorichm, and was validated as the predictive biomarkers exhibiting good performance with area under the curve (AUC) of 0.817 for discovery set and 0.882 for validation set.Conclusions The candidate protein panel discovered may aid in pSS diagnosis. Salivary proteomic analysis is a promising non-invasive method for prognostic evaluation and early and precise treatments for pSS patients. DIA offers the best time efficiency and data dependability and may be a suitable option for future research on the salivary proteome.

Moving together or left behind? An examination of rural migrant working mothers' childcare strategies in the cities.

BACKGROUND: In China, an increasing number of rural mothers participate in urban labour markets, but little is known about their decisions regarding childcare while living in these cities. Why do some rural mothers migrate to the cities with their children, whereas others leave their children behind in the countryside? METHODS: This study analysed 1852 samples from the 2016 China Migrant Dynamic Survey of rural migrant mothers collected in the Pearl River Delta (PRD). These mothers were registered with agricultural hukou outside of the PRD and had at least one child under 18 years of age. RESULTS: The results indicated that 57.8% of these mothers migrated together with their children. Rural migrant mothers who were self-employed, had a higher level of household income on a log10 scale and had a longer duration of migration were more willing to adopt closely performing motherhood than rural migrant mothers who were not self-employed. Additionally, rural working mothers who were intra-provincial migrants and had a smaller number of children were more likely to bring their children to the cities than rural working mothers who were inter-provincial migrants. CONCLUSIONS: This study works to strengthen the understanding of rural migrant working mothers' childcare strategies, provide insights for future policy studies and contribute to evidence-based recommendations for policymakers regarding internal rural-to-urban migration, migrant women and the wellbeing of the families of migrants.

Modelling Impact of High-Rise, High-Density Built Environment on COVID-19 Risks: Empirical Results from a Case Study of Two Chinese Cities.

Characteristics of the urban environment (e.g., building density and road network) can influence the spread and transmission of coronavirus disease 2019 (COVID-19) within cities, especially in high-density high-rise built environments. Therefore, it is necessary to identify the key attributes of high-density high-rise built environments to enhance modelling of the spread of COVID-19. To this end, case studies for testing attributes for modelling development were performed in two densely populated Chinese cities with high-rise, high-density built environments (Hong Kong and Shanghai).The investigated urban environmental features included 2D and 3D urban morphological indices (e.g., sky view factor, floor area ratio, frontal area density, height to width ratio, and building coverage ratio), socioeconomic and demographic attributes (e.g., population), and public service points-of-interest (e.g., bus stations and clinics). The modelling effects of 3D urban morphological features on the infection rate are notable in urban communities. As the spatial scale becomes larger, the modelling effect of 2D built environment factors (e.g., building coverage ratio) on the infection rate becomes more notable. The influence of several key factors (e.g., the building coverage ratio and population density) at different scales can be considered when modelling the infection risk in urban communities. The findings of this study clarify how attributes of built environments can be applied to predict the spread of infectious diseases. This knowledge can be used to develop effective planning strategies to prevent and control epidemics and ensure healthy cities.

Association between social integration and risk of dementia: A systematic review and meta-analysis of longitudinal studies.

BACKGROUND: Dementia is an emerging public health issue. Growing evidence emerged on the association between social integration and the risk of dementia. However, the magnitude of the association between different aspects of social integration and the risk of dementia is unclear. METHODS: Five databases were systematically searched. Newcastle-Ottawa scale for assessing the quality of the reporting was used for quality appraisal. Longitudinal cohort studies examining the association between social integration and the risk of dementia were analyzed using random effects model. A series of sensitivity analyses was conducted to enhance the robustness of the findings. RESULTS: Forty publications generated from 32 studies/databases were included. The meta-analysis showed that strong social engagement (overall RR = 0.81, 95% CI = 0.74-0.89, p < 0.001) and frequent social contact (overall RR = 0.86, 95% CI = 0.76-0.97, p = 0.018) were positively associated with decreased risk of dementia. The influence of social support (overall RR = 0.92, 95% CI = 0.80-1.06, p = 0.238) and close social contact (overall RR = 0.74, 95% CI = 0.48-1.13, p = 0.167) was not significant. Loneliness was significantly associated with an increased risk of dementia (overall RR = 1.42, 95% CI = 1.26-1.60, p < 0.001), whereas the influence of social isolation (overall RR = 1.58, 95% CI = 0.80-3.12, p = 0.192) was not significant. A larger social network size (RR = 0.75, 95% CI = 0.59-0.97, p = 0.028) was a promising influencing factor even though the number of studies was insufficient for a meta-analysis. However, the heterogeneity among studies was generally high even though sensitivity analysis was conducted. CONCLUSIONS: Our findings reveal that high social engagement and frequent social contact are significantly associated with a lower risk of dementia, whereas loneliness is associated with a higher risk. The promising impact of large social network size is also identified. Substantial heterogeneity appeared in most of the analysis, making the inference tentative. Nevertheless, the sensitivity analysis provided valuable implications that enhancing social engagement and reducing loneliness may prevent or delay the onset of dementia among middle-aged and older adults.

Analysis of the saliva metabolic signature in patients with primary Sjögren's syndrome.

BACKGROUND: The saliva metabolome has been applied to explore disease biomarkers. In this study we characterized the metabolic profile of primary Sjögren's syndrome (pSS) patients and explored metabolomic biomarkers. METHODS: This work presents a liquid chromatography-mass spectrometry-based metabolomic study of the saliva of 32 patients with pSS and 38 age- and sex-matched healthy adults. Potential pSS saliva metabolite biomarkers were explored using test group saliva samples (20 patients with pSS vs. 25 healthy adults) and were then verified by a cross-validation group (12 patients with pSS vs. 13 healthy adults). RESULTS: Metabolic pathways, including tryptophan metabolism, tyrosine metabolism, carbon fixation, and aspartate and asparagine metabolism, were found to be significantly regulated and related to inflammatory injury, neurological cognitive impairment and the immune response. Phenylalanyl-alanine was discovered to have good predictive ability for pSS, with an area under the curve (AUC) of 0.87 in the testing group (validation group: AUC = 0.75). CONCLUSION: Our study shows that salivary metabolomics is a useful strategy for differential analysis and biomarker discovery in pSS.

Effectiveness of case-based learning in Chinese dental education: a systematic review and meta-analysis.

OBJECTIVE: The application of case-based learning (CBL) pedagogy has been emerging as an improved and more practical learning method across the Chinese dental education system. This article provides a critical overview of CBL pedagogy and further assesses the effectiveness of this teaching model in Chinese dental education. DESIGN: A systematic review and meta-analysis. METHODS: Studies published up to December 2019 were searched in the following electronic databases: China National Knowledge Infrastructure, China Science Periodical Database, Chinese Biomedical documental database, Wanfang data, PubMed, EMBASE and Cochrane Central Register of Control Trials. All randomised controlled trials (RCTs) that compared the effectiveness of the CBL teaching model and the traditional lecture-based learning (LBL) model in all dental disciplines were included. The assessment of methodological quality was based on the guidelines described in the Cochrane Handbook for Systematic Reviews, and the meta-analysis was performed using the software RevMan V.5.3 RESULTS: A total of 30 RCTs were finally included, with a total sample size of 2356 dental students. The CBL pedagogy significantly increased knowledge scores (standardised mean difference (SMD)=1.58, 95% CI: 0.95 to 2.20, p<0.0001), skill scores (SMD=1.22, 95% CI: 0.34 to 2.11, p<0.0001), comprehensive ability scores (SMD=1.91, 95% CI: 1.74 to 4.07, p<0.0001) and teaching satisfaction (risk ratio=1.38; 95% CI: 1.15 to 1.65; p=0.01) compared with the LBL teaching model among the dental students. Additionally, a subgroup analysis showed significant differences in the effects of CBL on knowledge scores, skill scores and comprehensive ability scores when comparing theoretical and practical courses. CONCLUSIONS: The meta-analysis and systematic review of the eligible literature showed that the CBL pedagogy in Chinese dental education is an effective way to increase knowledge scores, skill scores, comprehensive ability scores and teaching satisfaction. Successful adaptation of this teaching model could solve the scarcity of highly skilled and professional dentists in dental schools and hospitals across China.

Mapping a postgraduate curriculum in disaster nursing with the International Council of Nursing's Core Competencies in Disaster Nursing V2.0: The extent of the program in addressing the core competencies.

BACKGROUND: The increasing frequency and magnitude of disasters call for enhancing the preparation of nurses with advanced knowledge and skills in disaster management. OBJECTIVES: With the release in December 2019 of the updated version 2.0 of the ICN's Core Competencies in Disaster Nursing (ICN CCDN V2.0), the aims of this study were to examine the extent to which the selected disaster nursing postgraduate program curriculum and the dissertation projects address the updated core competencies and to determine whether the syllabus requires revision. METHODS: A data mapping analysis approach was used to review the syllabus of the studied program for coverage of the ICN V2.0 core competencies for general professional (Level I) and advanced/specialized nurses (Level II). The dissertation projects of the students were also included in the mapping analysis. RESULTS: It found that 83% of the core competencies were addressed at Level I for general professional nurses and 69% at Level II for advanced/specialized nurses in the curriculum. Out of the 35 core competencies at Level I under the eight domains, six items (17.1%) were not covered under the domains of Intervention and Recovery. Out of the 32 core competencies at Level II, ten items (31.3%) were not covered under the domains of Communication, Incident Management, Safety and Security, Assessment, Intervention, and Law and Ethics. Students' dissertations could complement some of the competencies not covered in the syllabus. CONCLUSIONS: The studied curriculum covered the majority of the core competencies proposed by ICN CCDN V2.0, but subjects were required to be revised to address the competencies missing from the syllabus. Moreover, it is critically important for educators to review their curriculum to prepare nurses for disasters, to ensure that they are equipped with the competencies required to meet the demands arising from the increasingly frequent occurrences of global disaster.

Associations of low level of fluoride exposure with dental fluorosis among U.S. children and adolescents, NHANES 2015-2016.

Drinking water fluoridation was a mid-twentieth century innovation based on the medical hypothesis that consuming low doses of fluoride at the teeth forming years provided protection against dental decays. Numerous studies showed that high level exposure to fluoride could cause dental and skeleton fluorosis. However, there was limited study focusing on the fluorosis effect of low levels of exposure to fluoride. Therefore, our study aimed to examine whether the low level of fluoride exposure (measured in blood plasma and household tap water) was associated with the risk of dental fluorosis based on data of the National Health and Nutrition Examination Survey (NHANES) 2015-2016. We analyzed data in 2098 children and adolescents who had Dean's Index scores, and water and plasma fluoride measures. The Dean's Index score was measured by calibrated dental examiners using the modified Dean's fluorosis classification system. Fluoride was measured in plasma and household tap water. In this study, we found that the rate of fluoride concentration in water above the recommended level of 0.7 mg/L was 25%, but the prevalence of dental fluorosis was 70%. Binary logistic regression adjusted for covariates showed that higher water fluoride concentrations (0.31-0.50, 0.51-0.70, > 0.70 compared 0.00-0.30) were associated with higher odds of dental fluorosis (OR = 1.48, 95% CI: 1.13-1.96, p = 0.005; OR = 1.92, 95% CI: 1.44-2.58, p < 0.001, and OR = 2.30, 95% CI: 1.75-3.07, p < 0.001, respectively). The pattern of regression between plasma fluoride and dental fluorosis was similar. Inclusion, our study showed that even low level of water or plasma fluoride exposure was associated with increased the risk of dental fluorosis. The safety of public health approach of drinking water fluoridation for global dental caries reduction are urgently needed further research.

Development of disaster nursing education and training programs in the past 20 years (2000-2019): A systematic review.

BACKGROUND: Nurses play a pivotal role in disaster management across the globe. With the call for all nurses to be prepared for disasters, disaster nursing education and training programs have expanded globally. However, a clear picture of the development and coverage of disaster nursing education and training programs is lacking. OBJECTIVES: This study aimed to establish an overall picture of the development of disaster nursing education and training programs in the last 20 years, outline the contents included, approaches adopted and outcomes reported. METHODS: A systematic search for relevant literature published between January 2000 to December 2019 was conducted using electronic databases including the CINAHL, MEDLINE, PubMed, Web of Science, and Scopus with the keywords on disaster nursing education and training. FINDINGS: A total of 75 eligible studies were identified from 3395 potentially relevant articles. The numbers of disaster nursing education and training programs increased gradually over the past 20 years. They were offered in various countries with an unbalanced geographical distribution. Most of the existing programs focused on disaster preparedness and response, especially on the skills of triage during disaster response, instead of addressing the full spectrum of disaster management that included mitigation, preparedness, response, and recovery phases. Multiple approaches and technologies were adopted, including competency-based, all-hazard, inter-professional, flipped classroom, simulation, tabletop exercises, and virtual reality ones. Nearly half of the included programs adopted a pre- and post-test evaluation to examine the outcomes of learning and all of the programs reported significant increases in nursing professionals' knowledge and skills of related content on disaster management covered in the training programs. CONCLUSIONS: This review provides nurse leaders, educators and researchers in nursing with an understanding of the state-of-art of the existing disaster nursing education and training programs. More disaster nursing research are necessary to enhance the knowledge, skills and readiness of the nursing professionals for disaster management in meeting global disaster challenges.

Radiomics-based comparison of MRI and CT for differentiating pleomorphic adenomas and Warthin tumors of the parotid gland: a retrospective study.

OBJECTIVE: The objective of this study was to compare the diagnostic performance of magnetic resonance imaging (MRI) and computed tomography (CT) in differentiating pleomorphic adenomas from Warthin tumors using radiomics. STUDY DESIGN: We retrospectively reviewed 626 patients who underwent preoperative MRI or CT for parotid tumor diagnosis. Patient groups were balanced by propensity score matching (PSM) and 123 radiomic features were extracted from tumor images. Radiomic signatures (rad-scores) were generated using a least absolute shrinkage and selection operator logistic regression model. The Canny edge detector was used to define tumor borders (border index). The diagnostic performance of rad-score and border index before and after PSM was evaluated with area under the receiver operating characteristic curve analysis. RESULTS: For differentiation of pleomorphic adenomas and Warthin tumors, rad-score and border index areas under the curve for MRI after PSM were 0.911 (95% confidence interval [CI], 0.871-0.951) and 0.716 (95% CI, 0.646-0.787), respectively; those for CT were 0.876 (95% CI, 0.829-0.923) and 0.608 (95% CI, 0.527-0.690), respectively. Tumor border index on MRI, but not CT, had superior diagnostic performance (P < .05); MRI- and CT-based rad-scores showed similar performance (P >.05). CONCLUSIONS: MRI is superior to CT for tumor margin examination; however, the radiomics features of both modalities showed no difference.

Individual Disaster Preparedness in Drought-and-Flood-Prone Villages in Northwest China: Impact of Place, Out-Migration and Community.

Rural communities are generally more vulnerable to natural hazards when compared to urban communities. Moreover, rural communities are diverse and unique in their place, population, agricultural production and culture, which make it challenging for different rural settings to prepare for disasters. There is a little comparison made about the individual disaster preparedness among rural communities with different geographic landforms. In this study, we examined the individual disaster preparedness of rural residents in three drought-and-flood-prone villages with different landforms (plains, loess plateau and mountains) via a cross-sectional self-report structured questionnaire survey conducted in Northwest China. We also adopted an ecological framework to examine the determinants of villagers' individual disaster preparedness across different dimensions: place, individual sociodemographic factors, family socioeconomic status, hazard adaptations, community and neighbourhood influences. We found that place was a significant factor for disaster preparedness when controlling individual sociodemographic and family socioeconomic factors. The level of preparedness in the plains was higher than both mountains and plateau. Moreover, the villagers who had out-migrated to work reported a higher level of disaster preparedness than did local villagers. In addition, the community and neighbourhood played an important role in determining individual disaster preparedness. This research highlights the needs for tailored community-based disaster risk reduction programs to improve villagers' knowledge and skills of disaster preparedness.

Effects of laser debonding treatment on the optical and mechanical properties of all-ceramic restorations.

The objective of this study was to evaluate how erbium-doped yttrium aluminium garnet (Er:YAG) laser debonding treatment affects the optical and mechanical properties of dental ceramics. In total, 120 rectangular (22*5*1.2 mm) IPS E.max Press specimens were fabricated and divided into 4 groups: the control group, 3 W laser group, 4 W laser group, and 5 W laser group. For each group, 10 specimens were used for the colour test (colour difference (△E) and transparency parameter (TP)), 10 specimens were used for the flexural strength test, and 10 were used for the Vickers hardness test. One random sample from each colour test specimens was observed by scanning electron microscopy (SEM). The L*, a*, b*, △E, TP, flexural strength, and Vickers hardness values were measured and calculated. According to the Kruskal-Wallis test, the L*, a*, and b* values showed no significant variations (P > 0.05), except for the b* value in the 5 W laser group (P < 0.05). The △E, TP, flexural strength, and Vickers hardness values were analysed by one-way analysis of variance (ANOVA). The 5 W laser group exhibited a higher △E value, which exceeded the perceptible threshold and significantly lower TP values than the other groups (P < 0.05). The mean flexural strength and Vickers hardness values after Er:YAG laser debonding revealed no significant changes (P > 0.05). Microcracks were detected during the SEM analysis of the 5 W laser group. Er:YAG laser debonding treatment did not affect the mechanical properties, but changed the optical properties of dental ceramics.

Magnetic resonance image biomarkers improve differentiation of benign and malignant parotid tumors through diagnostic model analysis.

OBJECTIVES: To explore the effectiveness of magnetic resonance image (MRI)-based biomarkers for identifying benign and malignant parotid tumors via diagnostic model analysis. METHODS: This retrospective study included 109 patients (development cohort and validation cohort) who underwent MRI preoperatively, including T1- and T2-weighted images. Parameters based on 2D or 3D texture analysis were extracted from tumor lesions by MaZda software, fisher discriminant and bootstrap method were used to perform parameter reduction, diagnostic models with the selected biomarkers were established along with clinical data, model performance (discrimination and calibration) was furtherly evaluated by internal and external validation, decision curve analysis was applied to measure the improvement of clinical benefits. RESULTS: S(5,5) Entrop, S(0,1) ASM, WavEnHH (s-4), S(1,1,0) Entropy and Perc.10% were significantly associated with the pathological diagnosis of parotid tumor (benign versus malignancy), when adding these biomarkers to the regression analysis, model performance significantly improved in the development cohort (likelihood-ratio-test; p < 0.05, with an increase of AUC from 0.72 (reference model) to 0.85), and these results were maintained in a small external validation cohort. Decision curve analysis indicated that clinical benefit was greater with the application of MRI-based biomarkers. CONCLUSIONS: MRI-based texture analysis is proven to be an effective tool in differentiating benign and malignant parotid tumors, preoperative diagnosis was improved with the selected biomarkers compared to the reference model.

ICD-11 Posttraumatic Stress Disorder and Complex PTSD Among Hospital Medical Workers in China: Impacts of Wenchuan Earthquake Exposure, Workplaces, and Sociodemographic Factors.

BACKGROUND: Previous studies address posttraumatic stress disorder (PTSD) following disasters as a public health issue. However, few studies investigate the long-term effect of disaster exposure on PTSD among hospital medical workers (HMWs). OBJECTIVES: This study aimed to study the prevalence of ICD-11 PTSD and complex PTSD (CPTSD) among exposed and non-exposed HMWs 11 years after the Wenchuan earthquake in China, to identify the factors associated with PTSD and CPTSD scores, and to examine the factor structures of PTSD and CPTSD models. METHODS: A cross-sectional study was conducted using a self-administered online questionnaire. Two thousand fifty-nine valid samples were collected from four hospitals in 2019. Descriptive statistical analysis, multivariate regression models, and confirmatory factor analysis (CFA) were performed. RESULTS: The prevalence of PTSD and CPTSD was 0.58 and 0.34%, respectively. The unexposed group reported higher PTSD and CPTSD scores than the exposed group. The type of workplace and marital status were significantly associated with the PTSD and CPTSD scores of HMWs. The CFA results indicate that both the correlated first-order model and the correlated two-layer model were a good fit to explain the structure of PTSD and CPTSD. CONCLUSION: These findings suggest that few HMWs who were exposed to the Wenchuan earthquake suffered from PTSD or CPTSD 11 years following the disaster. However, psychological support was still necessary for all HMWs, especially for unmarried HMWs who were Working in smaller hospitals. Further research is required to analyze mental health status using ICD-11 PTSD and CPTSD to provide ongoing evidence to help HWMs cope effectively with the challenges of future disasters.

An illumination of the ICN's core competencies in disaster nursing version 2.0: Advanced nursing response to COVID-19 outbreak in China.

AIM: This study aims to report on the actions and incident management of the advanced practice nurses of a disaster operation team who were deployed in response to the COVID-19 outbreak, and to explore how it illustrated the Core Competencies in Disaster Nursing Version 2.0 delineated by the International Council of Nurses in 2019. METHODS: This is a descriptive study. The participants (responders) communicated and reported their actions in the operation with headquarter on a popular social media platform in China (WeChat), established specifically for the three-rescue teams. RESULTS: The response approach of advanced nurses to COVID-19 encompassed six of the eight domains of the competencies outlined in ICN CCDN V2.0, namely on preparation and planning, communication, incident management systems, safety and security, assessment and intervention. CONCLUSIONS: The response teams of advanced practice nurses in this study clearly demonstrated their competencies in disaster rescue, which fulfilled most of the core competencies set forth by the ICN. IMPLICATIONS FOR NURSING MANAGEMENT: The findings of this study contributed to understand the roles played by advanced practice nurses and nurse managers in disaster management and how these relate to the competencies set forth by the ICN.

Personal Cold Protection Behaviour and Its Associated Factors in 2016/17 Cold Days in Hong Kong: A Two-Year Cohort Telephone Survey Study.

Background: Despite larger health burdens attributed to cold than heat, few studies have examined personal cold protection behaviours (PCPB). This study examined PCPB during cold waves and identified the associated factors in a subtropical city for those without central heating system. Methods: A cohort telephone survey was conducted in Hong Kong during a colder cold wave (2016) and a warmer cold wave (2017) among adults (≥15). Socio-demographic information, risk perception, self-reported adverse health effects and patterns of PCPB during cold waves were collected. Associated factors of PCPB in 2017 were identified using multiple logistic regression. Results: The cohort included 429 subjects. PCPB uptake rates were higher during the colder cold wave (p < 0.0005) except for ensuring indoor ventilation. Of the vulnerable groups, 63.7% had low self-perceived health risks. High risk perception, experience of adverse health effects during the 2016 cold wave, females and older groups were positive associated factors of PCPB in 2017 (p < 0.05). Conclusions: PCPB changed with self-risk perception. However vulnerable groups commonly underestimated their own risk. Indoor ventilation may be a concern during cold days in settings that are less prepared for cold weather. Targeted awareness-raising promotion for vulnerable groups and practical strategies for ensuring indoor ventilation are needed.

Nitrogen Fertilization Restructured Spatial Patterns of Soil Organic Carbon and Total Nitrogen in Switchgrass and Gamagrass Croplands in Tennessee USA.

Nitrogen (N) fertilizers can potentially alter spatial distribution of soil organic carbon (SOC) and total nitrogen (TN)  concentrations in croplands such as switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.), but it remains unclear whether these effects are the same between crops and under different rates of fertilization. 13C and 15N are  two important proxy measures of soil biogeochemistry, but they were rarely examined as to their spatial distributions in soil. Based on a three-year long fertilization experiment in Middle Tennessee, USA, the top mineral horizon soils (0-15 cm) were collected using a spatially explicit design within two 15-m2 plots under three fertilization treatments in SG and GG croplands. A total of 288 samples were collected based on 12 plots and 24 samples in each plot. The fertilization treatments were no N input (NN), low N input (LN: 84 kg N ha-1 in urea) and high N input (HN: 168 kg N ha-1 in urea). The SOC, TN, SOC/TN (C: N), δ13C and δ15N were quantified and their within-plot variations and spatial distributions were achieved via descriptive and geostatistical methods. Results showed that SG generally displayed 10~120% higher plot-level variations in all variables than GG, and the plot-level variations were 20~77% higher in NN plots than LN and HN plots in SG but they were comparable in unfertilized and fertilized plots in GG. Relative to NN, LN and HN showed more significant surface trends and spatial structures in SOC and TN in both croplands, and the fertilization effect appeared more pronounced in SG. Spatial patterns in C: N, δ13C and δ15N were comparable among different fertilization treatments in both croplands. The descending within-plot variations were also identified among variables (SOC > TN > δ15N > C: N > δ13C). This study demonstrated that N fertilizations generally reduced the plot-level variance and simultaneously re-established spatial structures of SOC and TN in bioenergy croplands, which little varied with fertilization rate but was more responsive in switchgrass cropland.

Nitrogen Fertilization Elevated Spatial Heterogeneity of Soil Microbial Biomass Carbon and Nitrogen in Switchgrass and Gamagrass Croplands.

The effects of intensive nitrogen (N) fertilizations on spatial distributions of soil microbes in bioenergy croplands remain unknown. To quantify N fertilization effect on spatial heterogeneity of soil microbial biomass carbon (MBC) and N (MBN), we sampled top mineral horizon soils (0-15 cm) using a spatially explicit design within two 15-m2 plots under three fertilization treatments in two bioenergy croplands in a three-year long fertilization experiment in Middle Tennessee, USA. The three fertilization treatments were no N input (NN), low N input (LN: 84 kg N ha-1 in urea) and high N input (HN: 168 kg N ha-1 in urea). The two crops were switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.). Results showed that N fertilizations little altered central tendencies of microbial variables but relative to LN, HN significantly increased MBC and MBC:MBN (GG only). HN possessed the greatest within-plot variances except for MBN (GG only). Spatial patterns were generally evident under HN and LN plots and much less so under NN plots. Substantially contrasting spatial variations were also identified between croplands (GG > SG) and among variables (MBN, MBC:MBN > MBC). This study demonstrated that spatial heterogeneity is elevated in microbial biomass of fertilized soils likely by uneven fertilizer application in bioenergy crops.

Socio-demographic predictors of health and environmental co-benefit behaviours for climate change mitigation in urban China.

OBJECTIVE: This study aims to examine the patterns and socio-demographic predictors of health and environmental co-benefit behaviours that support climate change mitigation in a densely populated Asian metropolis-Hong Kong. METHODS: A population-based, stratified and cross-sectional random digit dialling telephone survey study was conducted between January and February 2016, among the Cantonese-speaking population aged 15 and above in Hong Kong. Socio-demographic data and the self-reported practice of 10 different co-benefit behaviours were solicited. Ethics approval and participant's verbal consent were sought. FINDINGS: The study sample consisted of 1,017 respondents (response rate: 63.6%) were comparable to the age, gender and geographical distributions of the Hong Kong population found in the latest 2011 Hong Kong Population Census. Among the co-benefit behaviours, using less packaging and disposable shopping bags were practiced in the highest frequency (70.1%). However, four behaviours were found to have never been practiced by more than half of the respondents, including bringing personal eating utensils when dining in restaurants or small eateries, showering less than five minutes, having one vegetarian meal a week, and buying more organic food. Results of multivariable logistic regression showed that frequency of practicing co-benefit behaviours were consistently associated with gender and age. CONCLUSION: Urban residents in Hong Kong do not engage in the practice of co-benefit behaviours in a uniform way. In general, females and older people are more likely to adopt co-benefit behaviours in their daily lives. Further research to assess the knowledge and attitudes of the population towards these co-benefit behaviours will provide support to relevant climate change mitigation policies and education programmes.

Syntheses, structural characterisation and electronic structures of ferrocenyl-osmafuran heterobinuclear organometallic complexes.

The heterobinuclear complex OsCl2(PPh3)2[CHC(PPh3)CFcO] (Fc = (C5H4)Fe(C5H5)) (1) in which the two metal centers were connected by the skeleton of the osmafuran and cyclopentadienyl was synthesized via a one-pot reaction of OsCl2(PPh3)3 and FcCOC[triple bond, length as m-dash]CH in high yield. Three derivatives (Os(η2-OCOO)(PPh3)2[CHC(PPh3)CFcO] (2), Os(NCS)2(PPh3)2[CHC(PPh3)CFcO] (3), and OsCl2(dppb)[CHC(PPh3)CFcO] (dppb = Ph2P(CH2)4PPh2) (4)) were obtained by the ligand substitution reactions of complex 1 with different reagents (Cs2CO3 (2), NaSCN (3) and dppb (4)), respectively. All of these complexes were characterized by NMR spectroscopy and elemental analysis and the structures of complexes 1, 3 and 4 were further confirmed by single crystal X-ray diffraction. Their electrochemical properties were studied by cyclic voltammetry and square wave voltammetry. The first redox wave was ascribed to the couple Os(ii)/Os(iii). All of these complexes exhibit two redox processes with a large peak separation. However, UV-Vis-NIR combined with theoretical calculation clearly indicated that (1) the Os center plays a major role in the one-electron oxidation process of heterobinuclear complexes 1-4 and the osmafuran could be better described as a carbene ligand; (2) the electronic communication between the Os and Fe center is absent, and the osmafuran with the electron-withdrawing phosphonium substituent actually functioned as an insulating bridge.