Associations of the perceived benefits and harms of COVID-19 with confidence in coping with the pandemic and mental health symptoms: a population-based survey in Hong Kong.

Introduction: Both perceived benefits and harms of COVID-19 have been reported, but whether they affect confidence in coping with the pandemic and mental health remains uncertain. Objective: To examine the association of perceived benefits and harms of COVID-19 with confidence in coping with the pandemic and mental health symptoms. Methods: A population-based survey was conducted on 7,535 Hong Kong adults from 22 February to 23 March 2021, when the 4th wave of COVID-19 was under control. Information on sociodemographic characteristics, perceived benefits (10 options) and harms (12 options) of COVID-19, confidence in coping with the pandemic (range 0-10), loneliness (range 0-4), anxiety (General Anxiety Disorders-2, range 0-6) and depression (Patient Health Questionnaire-2, range 0-6) was collected. Latent profile analysis was used to identify the combined patterns of perceived benefits and harms of COVID-19. The associations of combined patterns with confidence in coping with COVID-19, loneliness, anxiety, and depression were examined using linear regression (ß coefficient) adjusting for sociodemographic characteristics. Results: The combined patterns of perceived benefits and harms were classified into benefit (n = 4,338, 59.3%), harm (n = 995, 14.0%), and ambivalent (n = 2,202, 26.7%) groups. Compared with the ambivalent group, the benefit group had a significantly higher level of confidence (adjusted ß 0.46, 95% CI 0.33 to 0.58), and lower levels of loneliness (-0.35, -0.40 to-0.29), anxiety (-0.67, 0.76 to-0.59), and depression (-0.65, -0.73 to-0.57). The harm group had a significantly lower level of confidence (-0.35, -0.53 to-0.16), and higher levels of loneliness (0.38, 0.30 to 0.45), anxiety (0.84, 0.73 to 0.96), and depression (0.95, 0.84 to 1.07). Conclusion: Perceived greater benefit from COVID-19 was associated with better mental health and stronger confidence in coping with the pandemic.

Multi-trajectories of health-related quality of life and their associated factors in patients with nasopharyngeal carcinoma: A longitudinal study.

BACKGROUND: The trajectories of health-related quality of life (HRQoL) of nasopharyngeal carcinoma (NPC) during and after the treatment along with their associated factors are seldom investigated in longitudinal studies. This study aims to investigate the longitudinal trajectories of HRQoL over time and their associated factors in patients with newly diagnosed NPC. METHODS: Between July 2018 and September 2019, a total of 500 patients were finally involved in this study. HRQoL was measured at four time points, from before treatment to the follow-up period after treatment. Group-based multi-trajectory modeling was applied to identify trajectories of five HRQoL functioning domains during the longitudinal period. Multinomial logistic regression models were applied to investigate potential independent factors associated with the multi-trajectory groups. RESULTS: We identified four distinct multi-trajectory groups, including the "initially lowest functioning" group (19.8%), the "initially lower functioning" group (20.8%), the "initially higher functioning" group (46.0%), and the "consistently highest functioning" group (13.4%). Patients who were older than 45 years or had T4 stage disease were more likely to be in the "initially lowest functioning" group, while those with EBV DNA ≥ 1500 copies/mL before the treatment were more likely to be in the "initially lowest functioning" or the "initially lower functioning" groups. CONCLUSIONS: We report the presence of heterogeneity in HRQoL trajectories among patients with NPC, and found that older age, advanced T stage, and higher EBV DNA level before treatment were significantly associated with poor HRQoL trajectories. Further studies are needed to examine the generalizability of these identified HRQoL trajectories and their associations with psychosocial and survival outcomes.

Substantial increase in perceived benefits over harms of COVID-19 outbreak but persistent socioeconomic disparities: Comparison of two cross-sectional surveys in Hong Kong from 2020 to 2021.

Background: We have reported both perceived benefits and harms of the COVID-19 outbreak and their socioeconomic disparities amid the pandemic in Hong Kong. We further investigated whether such perceptions and disparities had changed after 10 months. Methods: Under the Hong Kong Jockey Club SMART Family-Link Project, we conducted two cross-sectional surveys online on perceived personal and family benefits and harms of the COVID-19 outbreak in Hong Kong adults in May 2020 (after Wave 2 was under control; N = 4,891) and in February and March 2021 (after Wave 4 was under control; N = 6,013). We collected sociodemographic information, including sex, age, education, household income, and housing. Using multivariate models of analysis of covariance (MANCOVA), we compared perceived benefits and harms and socioeconomic disparities between the two surveys. Results: Adjusting for sex and age, the prevalence of 17 out of 18 perceived personal and family benefits of COVID-19 outbreak increased (Ps < 0.001). Six of 11 perceived personal and family harms decreased (Ps < 0.001) and 4 increased (Ps < 0.001). The total number of perceived personal and family benefits increased substantially (Ps < 0.001), whereas that of perceived personal harms decreased (P = 0.01) and family harms remained stable (P > 0.05). Socioeconomic disparities, however, persisted-more perceived benefits in those with higher socioeconomic status (Ps < 0.001) and more perceived harms in those with lower (Ps ≤ 0.005). Conclusion: We have first reported that perceived personal and family benefits of the COVID-19 outbreak increased substantially over 10 months amid the pandemic, while perceived personal and family harms were lower and stable, respectively. Socioeconomic disparities of the perceived benefits and harms persisted, which need to be monitored and addressed urgently.

COVID-19 pandemic fatigue and its sociodemographic and psycho-behavioral correlates: a population-based cross-sectional study in Hong Kong.

Pandemic fatigue is a growing public health concern of the lingering COVID-19 pandemic. Despite its widespread mass media coverage, systematic empirical investigations are scarce. Under the Hong Kong Jockey Club SMART Family-Link Project, we conducted online and telephone surveys amid the pandemic in February to March 2021 to assess self-reported pandemic fatigue (range 0-10) in Hong Kong adults (N = 4726) and its associations with sociodemographic and psycho-behavioral (high vs low to moderate) variables. Data were weighted by sex, age, and education of the general population. Binary logistic regression models yielded adjusted odds ratios (aORs) for high pandemic fatigue (score ≥ 7) for sociodemographic and psycho-behavioral variables. 43.7% reported high pandemic fatigue. It was less common in older people (55-64 years: aOR 0.56, 95% CI 0.39-0.82; 65 + years: 0.33, 0.21-0.52) versus age group 18-24 years, but more common in those with tertiary education (1.36, 1.15-1.62) versus secondary or below. High pandemic fatigue was positively associated with depressive symptoms (aOR 1.83, 95% CI 1.55-2.17), anxiety symptoms (1.87, 1.58-2.20), loneliness (1.75, 1.32-2.31), personal fear of COVID-19 (2.61, 2.12-3.23), family fear of COVID-19 (2.03, 1.67-2.47), and current alcohol use (1.16, 1.00-1.33), but negatively associated with self-rated health (0.79, 0.68-0.92), personal happiness (0.63, 0.55-0.72), personal adversity coping capability (0.71, 0.63-0.81), family adversity coping capability (0.79, 0.69-0.90), family well-being (0.84, 0.73-0.97), family communication quality (0.86, 0.75-0.98), and frequent home exercise (0.82, 0.69-0.96; versus less frequent). We first used a single-item tool to measure COVID-19 pandemic fatigue, showing that it was common and associated with worse mental health, lower levels of personal and family well-being and alcohol use.

Association of family wellbeing with forwarding and verifying COVID-19-related information, and mediation of family communication quality.

Objective: We assessed the associations of family wellbeing with verifying and subsequently forwarding COVID-19-related information to family members and the mediating effect of the quality of family communication on these associations among Chinese adults in Hong Kong. Methods: Under the Jockey Club SMART Family-Link Project, we conducted an online population-based survey, using Family wellbeing Scale and questions related to the family communication quality and forwarding and verifying COVID-19 information. Data were collected from 4,891 adults in May 2020. Prevalence estimates of forwarding and verifying COVID-19 information were weighted by sex, age, and education of the general population, and their associations with family wellbeing (ranged 0-10) were analyzed using generalized linear models with mutual adjustment. Their interactive effects on family wellbeing and the mediating effects of family communication quality were examined. Results: In total, 53.9% of respondents usually/always forwarded COVID-19 information related to their family, 68.7% usually/always verified it before forwarding, and 40.9% did both. Greater family wellbeing was associated with usually/always forwarding [adjusted ß (95% CI): 0.82 (0.72-0.92)] and usually/always verifying [0.43 (0.32-0.55)] (both P < 0.001) the information. Forwarding and verifying such information showed an additive effect on family wellbeing [1.25 (1.11-1.40)]. Family communication quality mediated the associations of family wellbeing with forwarding (83.7%) and verifying (86.6%) COVID-19-related information. Conclusion: Forwarding COVID-19 information to family, verifying such information, and especially doing both, were associated with greater family wellbeing, being strongly mediated by the quality of family communication. Individuals should be encouraged to verify COVID-19-related information before forwarding it to family members amidst the COVID-19 pandemic.

Adversity coping capability and its associations with mental health and family wellbeing amid the COVID-19 pandemic in Hong Kong.

BACKGROUND: Adversity coping capability (ACC) is important amid the COVID-19 pandemic. We examined the associations of ACC as measured by our one-item ACC scale (ACC-1) with mental health, family well-being and validity of ACC-1 in Hong Kong. METHODS: A cross-sectional survey was conducted on Hong Kong Chinese adults aged ≥ 18 years by landline, mobile phone, and online survey from February to March 2021, when the fourth wave of COVID-19 was under control. ACC-1 consisted of the question: "How do you rate your capability to cope with adversities?" with higher scores (0-10) indicating stronger ACC. The associations of ACC with socioeconomic characteristics, resilience, mental health, and family wellbeing were examined by linear regression coefficients (ßs). Data were weighted by sex, age, and education of the general population. RESULTS: Of 7441 respondents, after weighing, 52.2% were female and 79.1% were aged 18 to 64 years. ACC-1 showed good construct validity, with higher ACC being associated with higher levels of resilience (adjusted ß = 0.29), personal happiness (0.55), family happiness (0.42), family wellbeing (0.41), and family communication quality (0.41), and lower levels of depressive symptoms (-0.30), anxiety (-0.30), loneliness (-0.15); incremental validity with additional contributions of ACC to mental health and family wellbeing; and known-group validity with older age and favorable socioeconomic characteristics showing higher ACC (all P < 0.02). Females (mean ± standard deviation: 6.04 ± 1.82 vs 6.15 ± 1.96 [male]) and unemployed respondents (5.30 ± 1.99 vs 6.11 ± 2.03 [in paid employment]) had lower ACC (all P ≤ 0.02). CONCLUSIONS: We have first shown that stronger ACC was associated with better mental health and family wellbeing, and the results support ACC-1 as a simple and valid measure of ACC.

Associations of Face-to-Face and Instant Messaging Family Communication and Their Contents With Family Wellbeing and Personal Happiness Amidst the COVID-19 Pandemic.

Background: Both face-to-face and instant messaging (IM) communication are important for families, but face-to-face communication has reduced amidst the COVID-19 pandemic. We examined the use and contents of both communication methods amidst the pandemic, their associations with family wellbeing and personal happiness, and the mediation effects of communication quality in Hong Kong Chinese adults. Methods: This population-based online survey enrolled 4,921 respondents in May 2020, who reported (i) any face-to-face or IM family communication when the pandemic was severe; (ii) communication contents being classified as neutral, positive, supportive, and negative; and (iii) communication quality, family wellbeing and personal happiness (score 0-10). Associations of family wellbeing and personal happiness with communication methods and contents (no communication excluded) were examined using linear regressions (ß), adjusting for each other, sex, age, socioeconomic status, and the number of cohabitants. Mediating effects of communication quality on these associations were examined. Prevalence estimates were weighted by sex, age, and education of the general population. Interactions of methods and contents were examined. Results: Of 4,891 included respondents (female: 52.9%, 45-54 years: 37.7%, ≥65 years: 21.3%), 7.1% reported no communication, 12.7% face-to-face communication only, 26.7% IM only, and 53.4% both methods. More males and those at younger ages, had lower socioeconomic status, or fewer cohabitants showed no family communication or face-to-face only. More respondents reported neutral (83.1-99.3%) than positive (42.1-62.2%), supportive (37.5-54.8%), and negative (10.9-34.5%) contents despite communication methods. Communication quality was higher with both methods than IM only, face-to-face only, and no communication (scores: 6.7 vs. 4.5-6.6, all P ≤ 0.02). Better family wellbeing and personal happiness were associated with using IM only (adjusted ßs: 0.37 and 0.48) and both methods (0.37 and 0.42) than face-to-face only, and positive (0.62 and 0.74) or supportive (0.45 and 0.46) contents (all P ≤ 0.001). Communication quality mediated 35.2-93.5% of these associations. Stronger associations between positive contents and family wellbeing showed in both methods and face-to-face only than IM only (P for interaction = 0.006). Conclusions: We have first shown that, amidst the COVID-19 pandemic, family IM communication and positive and supportive contents may promote family wellbeing and personal happiness. People with no family communication may need assistance.

Patterns of Perceived Harms and Benefits of the COVID-19 Outbreak in Hong Kong Adults: A Latent Profile Analysis.

The COVID-19 pandemic caused different types of harms and benefits, but the combined patterns of perceived harms and benefits are unclear. We aimed to identify the patterns of perceived harms and benefits of the COVID-19 outbreak and to examine their associations with socio-demographic characteristics, happiness, and changes in smoking and drinking. A population-based cross-sectional online survey was conducted in May 2020 on Hong Kong adults (N = 4520). Patterns of perceived harms and benefits of COVID-19 were identified using latent profile analysis. Their associations with socio-demographic characteristics, happiness, and changes in smoking and drinking were examined using multinomial logistic regression. We identified three distinct patterns: indifferent (66.37%), harm (13.28%), and benefit (20.35%). Compared with the indifferent subgroup, the harm subgroup was younger, less happy, and had increased drinking, and hence might be at higher risk, whereas the benefit subgroup was more likely to be female, live with one or more cohabitants, have postsecondary education, be happier, and have decreased drinking, and could be more adaptive. Future studies can target the harm subgroup to facilitate their positive adjustments.

A Population Study on COVID-19 Information Sharing: Sociodemographic Differences and Associations with Family Communication Quality and Well-Being in Hong Kong.

Family support through the sharing of information helps to shape and regulate the health and behaviours of family members, but little is known about how families are sharing COVID-19-related information, or about its associations with family communication quality and well-being. We examined the associations of COVID-19 information sharing methods with sociodemographic characteristics, the perceived benefits of information communication and technology (ICT) methods, and family communication quality and well-being in Hong Kong. Of 4852 respondents (53.2% female, 41.1% aged over 55 years), the most common sharing method was instant messaging (82.3%), followed by face-to-face communication (65.7%), phone (25.5%) and social media (15.8%). Female sex (adjusted prevalence ratio (aPR) 1.09), older age (aPRs 1.14-1.22) and higher household income (aPR 1.06) (all p ≤ 0.04) were associated with instant messaging use, while post-secondary education was associated with face-to-face (aPR 1.10), video call (aPR 1.79), and email (aPR 2.76) communications (all p ≤ 0.03). Each ICT sharing method used was associated with a higher likelihood of both reported benefits (aPRs 1.26 and 1.52), better family communication quality and family well-being (adjusted ßs 0.43 and 0.30) (all p ≤ 0.001). We have first shown that COVID-19 information sharing in families using both traditional methods and ICTs, and using more types of methods, was associated with perceived benefits and better family communication quality and well-being amidst the pandemic. Sociodemographic differences in COVID-19 information sharing using ICTs were observed. Digital training may help enhance social connections and promote family well-being.

Worsening trends in self-rated health and correlates in Chinese adolescents in Hong Kong: a population-based panel study from 1999/2000 to 2014/15.

OBJECTIVES: To examine the 15-year secular trends of self-rated health (SRH) and correlates in Chinese adolescents in Hong Kong. DESIGN: A territory-wide population-based panel data study. SETTING: Anonymised records of the annual health examination from the Student Health Service, Department of Health in Hong Kong. PARTICIPANTS: 397 324 students in Secondary 2 (US grade 8), 335 902 in Secondary 4 and 113 892 in Secondary 6 during the academic year 1999/2000 and 2014/15. OUTCOME MEASURES: SRH and lifestyles were self-reported using standardised questionnaires. Sex-standardised and age-standardised prevalence of very poor/poor SRH and its secular annual changes across sex, grade, weight status, breakfast habits, and frequency/duration of aerobic exercises were examined. Their disparities over time were examined by interactions with the academic year in generalised estimating equations. RESULTS: The overall prevalence of very poor/poor SRH increased from 9.3% (95% CI: 8.9% to 9.7%) in 1999/2000 to 15.5% (15.1% to 15.8%) in 2014/15. Very poor/poor SRH was more prevalent in girls (adjusted OR: 1.02), in those having unemployed parents (1.29), being overweight (1.42) or obese (2.62), eating breakfast away from home (1.27) and skipping breakfast (1.49) or doing <1 time/week or ≤60 min/week aerobic exercises (1.78 and 1.88, respectively) than others. The corresponding disparities increased over time (ratios of OR: 1.006-1.042). CONCLUSIONS: Increasing prevalence of very poor/poor SRH from 1999/2000 to 2014/15 was found among Hong Kong Chinese adolescents, which was greater in girls, adolescents being overweight/obese and those having unemployed parents or unhealthy lifestyles. Strategies to reduce health inequality should consider multiple factors, especially modifiable factors including lifestyles.

Late-onset or chronic overweight/obesity predicts low self-esteem in early adolescence: a longitudinal cohort study.

BACKGROUND: How weight status changes with time may affect self-esteem was seldom studied. We identified the distinct trajectories of overweight/obesity over age and assessed their associations with different domains of self-esteem in Hong Kong Chinese children. METHODS: Territory-wide longitudinal data of 48,558 children (girls: 50.0%; 6.3 ± 0.51 years) studying Primary 1 in the academic cohorts of 1995/96 and 1996/97 followed till Primary 6 were obtained from the Student Health Service of Hong Kong. Weight was annually measured and categorized as underweight/normal and overweight/obese and self-esteem was measured in Primary 6. Distinct trajectories of weight status were first identified using growth mixture modeling and their associations with low self-esteem were assessed by logistic regression. RESULTS: Four distinct overweight/obesity trajectories were identified: never (76.8%), late-onset (8.1%), early-onset (4.2%) and chronic (10.9%) overweight/obesity. Compared with children who were never overweight/obese, more of those in the late-onset or chronic overweight/obesity group showed low self-esteem and specific domains including general, social and academic/school-related (adjusted odds ratios: 1.20 - 1.43, all P < 0.001) except parent/home-related self-esteem (P = 0.36), whereas children being in the early-onset overweight/obesity group showed no significant difference (P ≥ 0.53) except a lower risk of low social self-esteem (adjusted odds ratio = 0.82, P = 0.03). CONCLUSIONS: Late-onset or chronic overweight/obesity predicted low general, social and academic/school-related self-esteem. Children who successfully reduced weight may have equal levels of self-esteem or even better social self-esteem than those being always underweight/normal weight. Overweight/obese children had a vulnerability to self-esteem in non-domestic environments.

Skipping Breakfast and Eating Breakfast Away From Home Were Prospectively Associated With Emotional and Behavioral Problems in 115,217 Chinese Adolescents.

BACKGROUND: Breakfast is deemed the most important meal of the day. We examined the prospective associations of breakfast habits with emotional/behavioral problems in adolescents and potential effect modification. METHODS: 115,217 Primary 6 students (United States Grade 6; mean age, 11.9; standard deviation [SD], 0.59 years) who attended the Student Health Service of Department of Health in Hong Kong in 2004/05, 2006/07, 2008/09 were followed till Secondary 6 (United States Grade 12). Emotional/behavioral problems were biennially examined using Youth Self-Report since Secondary 2 (United States Grade 8). Lifestyles were biennially examined using standardized questionnaires since Primary 6. Prospective associations of breakfast habit with emotional/behavioral problems and potential effect modification were examined using generalized estimating equations. RESULTS: Compared with eating breakfast at home, eating breakfast away from home was significantly associated with total emotional/behavioral problems and seven syndromes, including withdrawal, somatic complaints, anxiety/depression, thought problems, attention problems, delinquent behaviors, and aggressive behaviors (adjusted odds ratios [AORs] 1.22-2.04), while skipping breakfast showed stronger associations with the above problems and social problems (AORs 1.34-2.29). Stronger associations were observed in younger students for total and attention problems (P < 0.03) and in those with lower weight status for delinquent behaviors (P = 0.005). CONCLUSION: Eating breakfast away from home and especially skipping breakfast were prospectively associated with adolescent emotional/behavioral problems. The associations weakened with increasing age for total emotional/behavioral and attention problems, and weakened with higher weight status for delinquent behaviors, highlighting the vulnerability of younger and underweight children. If the associations are causal, increasing home breakfast may reduce adolescent emotional/behavioral problems and benefit psychosocial health.

Family E-Chat Group Use Was Associated with Family Wellbeing and Personal Happiness in Hong Kong Adults amidst the COVID-19 Pandemic.

Instant messaging (IM) is increasingly used for family communication amidst the COVID-19 pandemic. However, evidence remains scarce on how family e-chat groups were used and their associations with family and individual wellbeing amidst the pandemic. The numbers of family e-chat groups, functions used, and messages sent and received daily in groups were reported by 4890 adults in May 2020, and their associations with family wellbeing and personal happiness and the mediation effect of family communication quality were examined. Results showed that sending/receiving text messages was most commonly used, followed by receiving/sending photos/pictures, making voice calls, receiving/sending short videos and voice messages, and making video calls. Women and older people used more non-text functions. Higher levels of family wellbeing and personal happiness were associated with having more groups, receiving/sending photos/pictures, video calls, more IM functions used, and more IM messages received/sent daily. Forty-six point two to seventy-five point five percent of their associations with more groups and more functions used were mediated by family communication quality. People having more family e-chat groups and using more IM functions may be more resilient amidst the pandemic, while those without or with low use of family e-chat groups amidst the pandemic would need more attention and assistance in the presence of social distancing.

Increasing socioeconomic disparities in sedentary behaviors in Chinese children.

BACKGROUND: Sedentary behaviors are prevalent in Chinese children, however, the studies on their trends and socioeconomic disparities are scarce. We examined the time trends of daily television (TV) viewing and video game playing and the associated socioeconomic factors in Chinese children in Hong Kong, the most developed and westernized city in China. METHODS: In a panel data study involving 538,300 primary four and 510,294 primary six students from 1999/2000 to 2008/09, data on socioeconomic status, sedentary behaviors (TV viewing and video game playing) and other lifestyle habits were collected using a self-administered questionnaire. Trends in sedentary behaviors over time were assessed. Their socioeconomic disparities were examined by interactions in generalized estimating equations with the adjustment for weight status and extracurricular physical activities. RESULTS: The age and sex-standardized prevalence of ≥2 h daily TV viewing decreased from 51.4% (95% confidence interval [CI] 51.1-51.8%) in 1999/2000 to 43.8% (95% CI 43.4-44.2%) in 2008/09 (P for trend < 0.001), whereas that of ≥1 h daily video game playing increased from 8.2% (95% CI 7.9-8.4%) to 22.4% (95% CI 22.0-22.7%). Both sedentary behaviors were more prevalent in boys than girls, but the disparities decreased over time (Ratio of odds ratio [ROR] = 0.996 and 0.924 for TV viewing and video game playing, respectively). In contrast, both sedentary behaviors were increasingly more prevalent in children whose parents had lower education levels or non-managerial/professional occupations (ROR 1.006-1.082). CONCLUSIONS: Children in lower socioeconomic families in Hong Kong were increasingly at risk of having sedentary behaviors over years and thus deserve more attention. Effective strategies targeting children and/or their parents of lower socioeconomic status are needed to reduce sedentary behaviors.

Luminescent cadmium(ii) coordination polymers of 1,2,4,5-tetrakis(4-pyridylvinyl)benzene used as efficient multi-responsive sensors for toxic metal ions in water.

Reactions of Cd(NO3)2·4H2O with 1,2,4,5-tetrakis(4-pyridylvinyl)benzene (4-tkpvb) and 5-tert-butylisophthalic acid (5-tert-H2BIPA), 1,3,5-benzenetricarboxylic acid (1,3,5-H3BTC) or 1,4-naphthalenedicarboxylic acid (1,4-H2NDC) under solvothermal conditions afforded three two-dimensional (2D) Cd(ii) coordination polymers [Cd(4-tkpvb)(5-tert-BIPA)]n (1), [{Cd(4-tkpvb)(1,3,5-HBTC)}·0.5DMF]n (2) and [Cd(4-tkpvb)(1,4-NDC)]n (3). Compounds 1-3 were structurally characterized by IR, elemental analysis, powder X-ray diffraction, and single crystal X-ray diffraction. Compounds 1-3 possess unique 2D networks in which 1D double chains [Cd2L2]n (L = 5-tert-BIPA or 1,3,5-HBTC) (1-2) or 1D linear chains [Cd(1,4-NDC)]n (3) are linked by 4-tkpvb ligands. Upon UV light excitation, a 4-tkpvb solution in DMF showed an emission band centered at 446 nm with a shoulder at 475 nm. The addition of Hg2+ ions into the 4-tkpvb solution in DMF remarkably changed its colour from colourless to yellow under natural light, or from blue to grey yellow under UV light, which were clearly visible to the naked eye. Compounds 1-3 suspended in water could emit yellow-green light under UV light irradiation. The representative compound 1 was confirmed to be an uncommon multi-responsive luminescent sensor for Hg2+, CrO42- and Cr2O72- ions in water by the luminescence quenching method. The detection limits for these species were 0.15 µM (Hg2+), 0.08 µM (CrO42-) and 0.12 µM (Cr2O72-), respectively. The luminescence quenching mechanism studies revealed that these quenching processes were involved in either the interaction of Hg2+ with free pyridyl groups in 1 or the overlap between the absorption band of CrO42- or Cr2O72- and the excitation and/or emission bands of 1.

A study of genotoxicity and oxidative stress induced by mercuric chloride in the marine polychaete Perinereis aibuhitensis.

The marine polychaete worm Perinereis aibuhitensis was used to study the genotoxic effects of mercuric chloride by means of the comet assay and micronucleus (MN) test. P. aibuhitensis was subjected in vivo to two different concentrations of mercuric chloride (0.05mgL-1 and 0.5mgL-1) for 96h. The comet assay of coelomocytes demonstrated that TailDNA% values increased with extended exposure to or increased concentrations of HgCl2 (p<0.01). The frequency of MNs was the highest in the treatment with 96h of exposure at all concentrations (p<0.01). The genotoxic effect of HgCl2 was both dose- and time-dependent in exposed P. aibuhitensis. The activities of the antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidases (GPx) were also estimated. Significant variations in antioxidant enzyme activities depended on the sampling time and the concentrations of mercuric chloride. Compared with the control, the activities of the antioxidant enzymes (SOD and GPx) were elevated at the lower concentration of mercuric chloride (0.05mg L-1) (p<0.05) for shorter exposure periods (24h and 72h). At the higher concentration of mercury (0.5mgL-1), the activities of GPx and SOD were inhibited; no variation was observed. These results proved that the use of the comet assay and MN test in coelomocytes of P. aibuhitensis is appropriate for determining the levels of DNA damage and that P. aibuhitensis is a species that is sensitive to mercury pollutants. This species may be considered a suitable candidate for monitoring marine heavy metal pollution.

Synthesis of DMF-protected Au NPs with different size distributions and their catalytic performance in the Ullmann homocoupling of aryl iodides.

DMF-stabilized Au nanoparticles (NPs) with three different particle sizes were prepared by controlling the reaction temperatures and times. In the absence of any additional ligands, these Au NPs showed high catalytic activity in the Ullmann homocoupling of aryl iodides in DMF. The effects of Au particle size on the coupling reaction were investigated by the use of three Au catalysts with mean particle sizes of ca. 1.0 nm, 2.5 nm, and 5.5 nm, respectively. The catalytic activity of the Au NPs was found to be in the order of Au (2.5 nm) > Au (<1.0 nm) > Au (5.5 nm), indicating that surface Au atoms do not have the same catalytic activity toward such a homocoupling reaction.

Synthesis and structure of a ferric complex of 2,6-di(1H-pyrazol-3-yl)pyridine and its excellent performance in the redox-controlled living ring-opening polymerization of ε-caprolactone.

The reaction of FeCl3 with a pincer ligand, 2,6-di(1H-pyrazol-3-yl)pyridine (bppyH2), produced a mononuclear Fe(III) complex [Fe(bppyH2)Cl3] (1), which could be reduced to the corresponding Fe(II) dichloride complex [Fe(bppyH2)Cl2] (2) by suitable reducing agents such as Cp2Co or Fe powder. 1 and 2 exhibited a reversible transformation from each other with appropriate redox reagents. 1 could be utilized as a pre-catalyst to initiate the ring-opening polymerization of ε-caprolactone in the presence of alcohol but did not work. The 1/alcohol system displayed characteristics of a well-controlled polymerization with the resulting poly(ε-caprolactone) having low molecular weight distributions, a linear tendency of molecular weight evolution with conversion, and polymer growth observed for the sequential additions of ε-caprolactone monomer to the polymerization reaction. The polymerization was completely turned off by the in situ reduction of the catalytic Fe center via Cp2Co and then turned back upon the addition of [Cp2Fe]PF6. The rate of polymerization was modified by switching in situ between the Fe(III) and Fe(II) species.

Assembly of new Mo/Cu/S clusters from [Et4N][Tp*MoS(S4)] and Cu(I) salts: syntheses, structures and third-order nonlinear optical properties.

Reactions of [Et4N][Tp*MoS(S)4] (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) (1) with 3 equiv. of CuX (X = Cl, Br, I, CN) or [Cu(MeCN)4]ClO4 in CH2Cl2-MeCN or CH2Cl2-DMF afforded [Et4N]2[Tp*Mo(µ3-S)3(CuCl)3(µ3-Cl)] (2), [Et4N][Tp*Mo(µ3-S)3(CuX)3] (3: X = Br; 4: X = I), [Et4N][Tp*MoO(µ-S)2(CuX)] (5: X = I; 6: X = CN) and [Tp*Mo(µ3-S)3Cu3(µ3-S')]4 (7). Compounds 2-7 were characterized by elemental analysis, IR spectra, UV-vis spectra, (1)H NMR, electrospray ion mass spectra (ESI-MS) and X-ray crystallography. The cluster dianion of 2 has a complete cubane-like [Tp*Mo(µ3-S)3(CuCl)3(µ3-Cl)] structure while the anion of 3 or 4 consists of an incomplete cubane-like [Tp*Mo(µ3-S)3(CuX)3] structure. The anion of 5 or 6 has a binuclear structure, in which one [Tp*MoO(µ-S)2] moiety and one CuX unit are linked by a pair of µ-S atoms. The structure of 7 may be considered as a supercube whose eight corners are occupied by four incomplete cubane-like [Tp*Mo(µ3-S)3Cu3] fragments and four µ3-S' atoms. The third-order nonlinear optical (NLO) properties of 2-6 in DMF were investigated by femtosecond degenerate four-wave mixing (DFWM) technique with a 80 fs pulse width at 800 nm. Compounds 2-6 exhibited good NLO performances and their NLO responses were enhanced relative to that of 1.

An unprecedented octahedral {Cd30} nanocage supported by twelve pendant-armed tetraacetate macrocyclic ligands.

An unprecedented octahedral {Cd(30)} nanocage supported by twelve pendant-armed tetraacetate macrocyclic ligands was synthesized through the reaction of macrocyclic tetraethyl ester and Cd(OAc)(2)·2H(2)O in a 1 : 2 stoichiometry, where the surface photovoltage and photoluminescent properties have been studied for the nanocage.