Editorial for Special Issue "Functional Graphene-Based Nanodevices".

As a typical ultra-thin two-dimensional nanomaterial, graphene has many excellent properties, including, but not limited to, mechanical, optical, thermal and electrical properties [...].

High-Performance Graphene Nanowalls/Si Self-Powered Photodetectors with HfO2 as an Interfacial Layer.

Graphene/silicon (Si) heterojunction photodetectors are widely studied in detecting of optical signals from near-infrared to visible light. However, the performance of graphene/Si photodetectors is limited by defects created in the growth process and surface recombination at the interface. Herein, a remote plasma-enhanced chemical vapor deposition is introduced to directly grow graphene nanowalls (GNWs) at a low power of 300 W, which can effectively improve the growth rate and reduce defects. Moreover, hafnium oxide (HfO2) with thicknesses ranging from 1 to 5 nm grown by atomic layer deposition has been employed as an interfacial layer for the GNWs/Si heterojunction photodetector. It is shown that the high-k dielectric layer of HfO2 acts as an electron-blocking and hole transport layer, which minimizes the recombination and reduces the dark current. At an optimized thickness of 3 nm HfO2, a low dark current of 3.85 × 10-10, with a responsivity of 0.19 AW-1, a specific detectivity of 1.38 × 1012 as well as an external quantum efficiency of 47.1% at zero bias, can be obtained for the fabricated GNWs/HfO2/Si photodetector. This work demonstrates a universal strategy to fabricate high-performance graphene/Si photodetectors.

A modified CVD method for the synthesis of monolayer MoS2and photoelectric improvement by HfO2passivation.

Molybdenum disulfide (MoS2) is an emerging class of new materials with a wide range of potential practical applications. However, the uncontrollability of monolayer MoS2synthesized by traditional chemical vapor deposition method and the low responsivity of MoS2photodetectors limit its further development in the field of photoelectric detection. To achieve controlled growth of monolayer MoS2and construct MoS2photodetectors with a high responsivity, we propose a novel single crystal growth strategy of high-quality MoS2by controlling the Mo to S vapor ratio near the substrate, and deposit a layer of hafnium oxide (HfO2) on the surface of MoS2to enhance the performance of the pristine metal-semiconductor-metal structure photodetector. At a reverse bias of 8 V, the HfO2passivated MoS2photodetector features an extremely high responsivity of1201AW-1,a response time of around 0.5 s, and a detectivity of7.7×1011Jones.Meanwhile, we deeply investigate the effect of the HfO2layer on the performance of the fabricated MoS2photodetector and propose a physical mechanism to interpret the obtained experiment results. These results might facilitate a better understanding on the performance modulation of the MoS2photodetectors and accelerate the development of MoS2-based optoelectronic devices.

Examination of Web-Based Single-Session Growth Mindset Interventions for Reducing Adolescent Anxiety: Study Protocol of a 3-Arm Cluster Randomized Controlled Trial.

BACKGROUND: Anxiety disorders are the most common mental disorders worldwide. In Hong Kong, 7% of adolescents are diagnosed with anxiety disorders, and 1 in every 4 secondary school students reports clinical-level anxiety symptoms. However, 65% of them do not access services. Long waitlists in public services, the high cost of private services, or the fear of being stigmatized can hinder service access. The high prevalence of anxiety and low intervention uptake indicate a pressing need to develop timely, scalable, and potent interventions suitable for adolescents. Single-session interventions (SSIs) have the potential to be scalable interventions for diagnosable or subclinical psychopathology in adolescents. Providing precise and context-adapted intervention is the key to achieving intervention efficacy. OBJECTIVE: This study aims to compare the effectiveness of three SSIs: single-session intervention of growth mindset on negative emotions (SIGMA), SSI of growth mindset of personality (SSI-GP), and active control, in reducing adolescent anxiety. METHODS: Adolescents (N=549, ages 12-16 years) from secondary schools will be randomized to 1 of 3 intervention conditions: the SIGMA, SSI-GP, or active control. The implementation of each intervention is approximately 45 minutes in length. Adolescent participants will report anxiety symptoms (primary outcome), perceived control, hopelessness, attitude toward help-seeking, and psychological well-being at preintervention, the 2-week follow-up, and the 8-week follow-up. A pilot test has confirmed the feasibility and acceptability of SIGMA among adolescents. We hypothesized that SIGMA and SSI-GP will result in a larger reduction in anxiety symptoms than the control intervention during the posttest and 8-week follow-up period. We also predict that SIGMA will have a more significant effect than SSI-GP. We will use the intention-to-treat principle and linear regression-based maximum likelihood multilevel models for data analysis. RESULTS: This study will be conducted from December 2022 to December 2023, with results expected to be available in January 2024. CONCLUSIONS: This protocol introduces the implementation content and strategies of growth mindset SSIs (consists of 2 forms: SIGMA and SSI-GP) among school students. The study will provide evidence on the efficacy of different growth mindset SSIs for adolescent anxiety. It will also establish implementation strategies for self-administrative SSIs among school students, which can serve as a pioneer implementation of a scalable and self-accessible brief intervention to improve the well-being of young people. TRIAL REGISTRATION: ClinicalTrials.gov NCT05027880; https://clinicaltrials.gov/ct2/show/NCT05027880. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/41758.

Uncovering sample heterogeneity in gaming and social withdrawal behaviors in adolescent and young adult gamers in Hong Kong.

OBJECTIVE: The current study aimed to examine the latent heterogeneity of gaming and social withdrawal behaviors in internet gamers and their associations with help-seeking behaviors. METHOD: The present study recruited 3430 young people (1874 adolescents and 1556 young adults) in Hong Kong in 2019. The participants completed the Internet Gaming Disorder (IGD) Scale, Hikikomori Questionnaire, and measures on gaming characteristics, depression, help-seeking, and suicidality. Factor mixture analysis was used to classify the participants into latent classes based on their latent factors of IGD and hikikomori in separate age groups. Latent class regressions examined the associations between help-seeking and suicidality. RESULTS: Both adolescents and young adults supported a 4-class, 2-factor model on gaming and social withdrawal behaviors. Over two-third of the sample were classified as healthy or low-risk gamers with low IGD factor means and low prevalence of hikikomori. Around one-fourth was moderate-risk gamers with elevated prevalence of hikikomori, higher IGD symptoms and psychological distress. A minority of the sample (3.8%-5.8%) belonged to high-risk gamers with the highest IGD symptoms and prevalence of hikikomori and heightened suicidal risks. Help-seeking in low-risk and moderate-risk gamers was positively associated with depressive symptoms and negatively associated with suicidal ideation. Perceived usefulness of help-seeking was significantly linked with lower likelihoods of suicidal ideation in the moderate-risk gamers and suicide attempt in the high-risk gamers. CONCLUSIONS: The present findings explicate the latent heterogeneity of gaming and social withdrawal behaviors and associated factors on help-seeking and suicidality among internet gamers in Hong Kong.

Measuring Online Social Support: Development and Validation of a Short Form for Chinese Adolescents.

Supportive interactions on social media have great potential to benefit adolescents' development. However, there is no instrument to measure online social support (OSS) in China. The study aimed to develop and validate a Chinese short version of the Online Social Support Scale (OSSS). The original scale was translated into Chinese through multiple forward and backward translation protocols. The calibration sample (N = 262) was used to select items and test the reliability, validity, and internal structure of the short form. The cross-validation sample (N = 267) was then used to assess measurement invariance by multigroup confirmatory factor analysis and examine criterion validity based on its relationships with life satisfaction, depression, and time on social media. The 20-item Chinese short version of OSSS (OSSS-CS) includes four factors: esteem/emotional support, social companionship, informational support, and instrumental support. Our results suggest that the OSSS-CS has high internal consistency, construct validity, and criterion validity. Furthermore, evidence of partial cross-validity demonstrated invariance of the variance-covariance matrices, factor structure, factor loadings, and factor variance across independent samples. The results also revealed that the original OSSS could be replicated across cultures. Finally, the short form developed in the study can be used as a reliable and valid measure of online social support among the Chinese adolescent population.

Online Peer-Support Group's Role in Addressing Filipino Domestic Workers' Social Support Needs: Content and Social Media Metrics Analysis.

The study aimed to examine what types of social support a prominent online peer support group has provided to Filipino domestic workers (FDWs) in Hong Kong (HK), how impactful each type of support was, and to what extent the support could address group members' expressed needs. Posts published from 1 September 2021 to 31 December 2021 in one of the largest online peer-support groups for FDWs in HK and their meta-data were extracted from Facebook. Thematic content analysis was performed to extract relevant information from the posts. Descriptive statistical analysis on the social media metrics was conducted to measure post impacts. A total of 599 posts published over the study period can be categorized to provide informational (76.67%), emotional (33.56%), and instrumental support (13.52%). Posts including emotional support were often more impactful. A total of 58 posts responded to requests explicitly expressed by individual FDWs, of which 13 required external resources. The online peer-support group acts as a new channel to raise FDWs' awareness of important issues related to their well-being, to encourage and facilitate them to seek formal and informal help, and to keep them emotionally attended to. Formal support services should recognize and collaborate with them and support their long-term sustainability.

Peer Support and Mental Health of Migrant Domestic Workers: A Scoping Review.

The effectiveness of peer support in improving mental health and well-being has been well documented for vulnerable populations. However, how peer support is delivered to migrant domestic workers (MDWs) to support their mental health is still unknown. This scoping review aimed to synthesize evidence on existing peer support services for improving mental health among MDWs. We systematically searched eight electronic databases, as well as grey literature. Two reviewers independently performed title/abstract and full-text screening, and data extraction. Twelve articles were finally included. Two types of peer support were identified from the included studies, i.e., mutual aid and para-professional trained peer support. MDWs mainly seek support from peers through mutual aid for emotional comfort. The study's findings suggest that the para-professional peer support training program was highly feasible and culturally appropriate for MDWs. However, several barriers were identified to affect the successful implementation of peer support, such as concerns about emotion contagion among peers, worries about disclosure of personal information, and lack of support from health professionals. Culture-specific peer support programs should be developed in the future to overcome these barriers to promote more effective mental health practices.

Relationship between online social support and adolescents' mental health: A systematic review and meta-analysis.

INTRODUCTION: The potential benefits of supportive interactions on social networking sites on adolescents' mental health are promising; however, no systematic evaluation has been conducted on this topic. This review examined empirical research on the relationship between social support derived from social networking sites and adolescents' mental health both theoretically and empirically. METHODS: Followed PRISMA guidelines, we conducted a systematic literature search on six English and three Chinese databases in February 2020. Four thousand one hundred and seventy-seven articles were screened first by title, then abstract, and lastly, full articles. RESULTS: Fourteen studies (five English and nine Chinese) were identified, with total sample of 11,616 adolescents (age: 10-19 years; females: 42.7%-56.3%). Meta-analysis showed that the correlation of online social support with self-esteem was moderate and significant (r = .29), but with depression was small and insignificant (r = -.09). Sensitivity analysis indicated that social support from acquaintances on the internet may not be as beneficial as from real-life acquaintances. Despite that there isn't enough research on other specific mental health outcomes to run a quantitative synthesis, individual studies suggest that online social support (OSS) may be associated with increased self-identity and life satisfaction, decreased loneliness and social anxiety, it also counteracts the negative effect of stress and cyberbullying on mental health. CONCLUSIONS: OSS might be beneficial for adolescents' mental health, especially self-esteem, although the causal relationship requires longitudinal studies to confirm, and the underlying mechanisms need further investigation.

Change in suicidal ideation and associated factors among young adults in Hong Kong from 2018 to 2019: a latent transition analysis.

PURPOSE: Suicide in young adulthood is a vital public health concern. There have been few systematic studies that examined the prevalence and transition of suicidal ideation classes in young adults and the factors associated with the transition. METHODS: This two-wave survey recruited 1269 young adults (Mean age = 24.0 years, 70.1% males) in Hong Kong. The participants completed the Suicidal Ideation Attributes Scale, Chinese Health Questionnaire, and help-seeking behaviors in 2018 and 2019. Latent profile analysis was used to classify the participants into latent classes of suicidal ideation with substantive checking under the 3-step approach. Latent transition analysis with measurement invariance examined the transition among the latent classes from 2018 to 2019 and the associations with help-seeking behaviors and change in psychological distress. RESULTS: Three latent classes of suicidal ideation were identified and over two-thirds of the participants belonged to the Low-risk class with minimal suicidal ideation. The prevalence of the High-risk class dropped from 10.2 to 7.2%, while that of the Moderate-risk class remained stable from 2018 to 2019. Increases in psychological distress predicted higher probabilities to remain at or transit into more risky classes. Engagement in help-seeking behaviors showed differential transitions in suicidal ideation across time. CONCLUSION: The findings suggest three latent classes of suicidal ideation with distinct profiles among the young adults. Deterioration in psychological distress showed a temporal effect on worsening of suicidal ideation over a 1-year period. Future studies should elucidate the comparative effectiveness of help-seeking behaviors via online and offline channels.

The Opportunities and Challenges of the First Three Years of Open Up, an Online Text-Based Counselling Service for Youth and Young Adults.

We present the opportunities and challenges of Open Up, a free, 24/7 online text-based counselling service to support youth in Hong Kong. The number of youths served more than doubled within the first three years since its inception in 2018 in response to increasing youth suicidality and mental health needs. Good practice models are being developed in order to sustain and further scale up the service. We discuss the structure of the operation, usage pattern and its effectiveness, the use of AI to improve users experience, and the role of volunteer in the operation. We also present the challenges in further enhancing the operation, calling for more research, especially on the identification of the optimal number of users that can be concurrently served by a counsellor, the effective approach to respond to a small percentage of repeated users who has taken up a disproportional volume of service, and the way to optimize the use of big data analytics and AI technology to enhance the service. These advancements will benefit not only Open Up but also similar services across the globe.

Who seeks help online? Comparing online and offline help-seeking preferences amongst youths with suicidal ideation.

BACKGROUND: Research consistently report an inverse relationship between suicide risk and help-seeking. The increasingly available internet-based support potentially offers an attractive alternative to traditional forms of assistance. The study compared the characteristics of suicidal youths in Hong Kong and their online and offline help-seeking behaviours. METHODS: Participants (N = 1214, age-range = 15-24 years) responded to the anonymous 2018 Hong Kong Online Survey on Youth Mental Health and Internet Usage. Respondents with suicidal thoughts were classified into those who sought help online and offline, or online only ("online-help"); those who sought help offline only ("offline-help"); and those who never sought help ("no-help"). They responded to questions concerning mental health, perception towards online support, internet use, help sources, and demographic information. RESULTS: The online-help group differed significantly from other groups, with greater suicidal ideation, distress, risk behaviours, and spent more time online for non-work-related purposes. Their perceived benefits of online support include anonymity, avoiding embarrassment, and social support. They are more likely to seek help from a combination of informal and formal sources. LIMITATIONS: No data on whether participants sought help online or offline first, and their current treatment status is available. Our study adopted conveniences sampling, and few respondents have sought help online exclusively. CONCLUSION: Online support offers an alternate way of engaging at-risk youths. Future clinical practice should consider online platforms as a complement, rather than a replacement, of offline platforms.

Applying text mining methods to suicide research.

OBJECTIVE: To introduce the research methods of computerized text mining and its possible applications in suicide research and to demonstrate the procedures of applying a specific text mining area, document classification, to a suicide-related study. METHOD: A systematic search of academic papers that applied text mining methods to suicide research was conducted. Relevant papers were reviewed focusing on their research objectives and sources of data. Furthermore, a case of using natural language processing and document classification methods to analyze a large amount of suicide news was elaborated to showcase the methods. RESULTS: Eighty-six papers using text mining methods for suicide research have been published since 2001. The most common research objective (72.1%) was to classify which documents exhibit suicide risk or were written by suicidal people. The most frequently used data source was online social media posts (45.3%), followed by e-healthcare records (25.6%). For the news classification case, the top three classifiers trained for classification tasks achieved 84% or higher accuracy. CONCLUSIONS: Computerized text mining methods can help to scale up content analysis capacity and efficiency and uncover new insights and perspectives for suicide research.

Effectiveness of a Malaysian Media Intervention Workshop: Safe Reporting on Suicide.

Background: Suicide remains an important cause of premature deaths and draws much media attention. However, unsafe reporting and portrayal of suicides by the media have been associated with increased risk of suicidal behavior. Current evidence suggests that media capacity-building could potentially prevent suicide. However, there are still knowledge gaps in terms of a lack of data on effective strategies for improving awareness and safe reporting of suicide-related media content. This study aims to investigate the effectiveness of a workshop conducted with members of the media community on the safe reporting of suicide-related content. Methods: An interventional single-arm pre and post pilot study was conducted on a sample of the Malaysian media community recruited through purposive and snowball sampling. The media safe reporting workshop was conducted by a suicide prevention expert with a media industry background. Thirty participants completed a self-reported evaluation questionnaire on their awareness and knowledge of reporting on suicide-related media content; before and after the interventional workshop. Results: There was a significant difference between the total scores before and after the intervention, with a large effect size. Post-intervention scores were significantly improved in 8 items, namely those related to the reporting of: (i) the content of any suicide note; (ii) headlines with methods of suicide; (iii) headlines with the location of suicide; (iv) cases of suspected suicide despite the unconfirmed cause of death; (v) suicide news to cater to readers' interests; (vi) cause of suicide; (vii) details of the location of suicide; and (viii) the negative impact to media community when reporting suicide stories. In particular, there was an improvement in the majority of items for people from the media community with no lived experience of suicidal behavior. Conclusion: The media safe reporting workshop is a potentially effective intervention for improving awareness and knowledge measures relating to safe reporting on suicide among the media community, with a more pronounced effect in those without lived experience of suicidal behavior. Limitations in the sample size, generalizability, short-term evaluation, and lack of a control group warrant future larger, longer-term controlled, and more representative studies.

Suicide Research in Mainland China, Hong Kong, and Macau Over Three Decades.

Background: China accounts for 15% of the global suicide death toll, yet suicide research efforts in the country are not well known by international colleagues. Aims: We aimed to outline the development of suicide research in China, appraise research findings, and identify key contributors. Method: English and Chinese research publication databases were systematically searched and relevant papers were reviewed. Chinese and English publications were compared. Results: There are almost 10 times more Chinese publications than English ones. The research focuses of and key contributors to the Chinese and English literature exhibit more differences than commonalities. The field experienced rapid expansion in the new millennium with more and higher quality publications and more funding support. Psychosocial-oriented perspectives guided most of the papers. Poisoning by pesticide as a suicide method and youth as a subpopulation group received the most research attention. Limitations: The scoping review does not provide in-depth syntheses on specific topics and does not include more recent publications. Conclusion: Research on suicide in China has been actively carried out during the 30-year period we reviewed, which might have contributed to suicide prevention in China. Research gaps identified by the review should be addressed to sustain the achievements.

Optimizing the Electronic Structure of In2O3 through Mg Doping for NiO/In2O3 p-n Heterojunction Diodes.

In2O3 is a wide bandgap oxide semiconductor, which has the potential to be used as an active material for transparent flexible electronics and UV photodetectors. However, the high concentration of unintentional background electrons existing in In2O3 makes it hard to be modulated by the electric field or form p-n heterojunctions with a sufficient band-bending width at the interface. In this work, we report the reduction of the background electrons in In2O3 by Mg doping (Mg-In2O3) and thereby improve the device performance of p-n diodes based on the NiO/Mg-In2O3 heterojunction. In particular, Mg doping compensates the free electrons in In2O3 and reduces the electron concentration from 1.7 × 1019 cm-3 without doping to 1.8 × 1017 cm-3 with 5% Mg doping. Transparent p-n heterojunction diodes were fabricated based on p-type NiO and n-type Mg-In2O3. The device performance was considerably enhanced by Mg doping with a high rectification ratio of 3 × 104 and a remarkable high breakdown voltage of >20 V. High-resolution X-ray photoelectron spectroscopy was used to investigate the interfacial electronic structure between NiO and Mg-In2O3, revealing a type II band alignment with a valence band offset of 1.35 eV and a conduction band offset of 2.15 eV. A large built-in potential of 0.98 eV was found for the undoped In2O3 but decreased to 0.51 eV for 5% Mg doping of In2O3. The NiO/Mg-In2O3 diodes with an improved rectification ratio and wider depletion region provide the possibility of achieving photodetectors with rapid photoresponse.

The Relationship Between Images Posted by New Mothers on WeChat Moments and Postpartum Depression: Cohort Study.

BACKGROUND: As social media posts reflect users' emotions, WeChat Moments, the most popular social media platform in China, may offer a glimpse into postpartum depression in the population. OBJECTIVE: This study aimed to investigate the features of the images that mothers posted on WeChat Moments after childbirth and to explore the correlation between these features and the mothers' risk of postpartum depression. METHODS: We collected the data of 419 mothers after delivery, including their demographics, factors associated with postpartum depression, and images posted on WeChat Moments. Postpartum depression was measured using the Edinburgh Postnatal Depression Scale. Descriptive analyses were performed to assess the following: content of the images, presence of people, the people's facial expressions, and whether or not memes were posted on WeChat Moments. Logistic regression analyses were used to identify the image features associated with postpartum depression. RESULTS: Compared with pictures of other people, we found that pictures of their children comprised the majority (3909/6887, 56.8%) of the pictures posted by the mothers on WeChat Moments. Among the posts showing facial expressions or memes, more positive than negative emotions were expressed. Women who posted selfies during the postpartum period were more likely to have postpartum depression (P=.003; odds ratio 2.27, 95% CI 1.33-3.87). CONCLUSIONS: The vast majority of mothers posted images conveying positive emotions during the postpartum period, but these images may have masked their depression. New mothers who have posted selfies may be at a higher risk of postpartum depression. TRIAL REGISTRATION: International Clinical Trials Registry Platform ChiCTR-ROC-16009255; http://www.chictr.org.cn/showproj.aspx?proj=15699.

Association between suicide reporting in the media and suicide: systematic review and meta-analysis.

OBJECTIVE: To examine the association between reporting on suicides, especially deaths of celebrities by suicide, and subsequent suicides in the general population. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed/Medline, PsychInfo, Scopus, Web of Science, Embase, and Google Scholar, searched up to September 2019. REVIEW METHODS: Studies were included if they compared at least one time point before and one time point after media reports on suicide; follow-up was two months or less; the outcome was death by suicide; and the media reports were about non-fictional suicides. Data from studies adopting an interrupted time series design, or single or multiple arm before and after comparisons, were reviewed. RESULTS: 31 studies were identified and analysed, and 20 studies at moderate risk of bias were included in the main analyses. The risk of suicide increased by 13% in the period after the media reported a death of a celebrity by suicide (rate ratio 1.13, 95% confidence interval 1.08 to 1.18; 14 studies; median follow-up 28 days, range 7-60 days). When the suicide method used by the celebrity was reported, there was an associated 30% increase in deaths by the same method (rate ratio 1.30, 95% confidence interval 1.18 to 1.44; 11 studies; median follow-up 28 days, range 14-60 days). For general reporting of suicide, the rate ratio was 1.002 (0.997 to 1.008; five studies; median follow-up 1 day, range 1-8 days) for a one article increase in the number of reports on suicide. Heterogeneity was large and partially explained by celebrity and methodological factors. Enhanced funnel plots suggested some publication bias in the literature. CONCLUSIONS: Reporting of deaths of celebrities by suicide appears to have made a meaningful impact on total suicides in the general population. The effect was larger for increases by the same method as used by the celebrity. General reporting of suicide did not appear to be associated with suicide although associations for certain types of reporting cannot be excluded. The best available intervention at the population level to deal with the harmful effects of media reports is guidelines for responsible reporting. These guidelines should be more widely implemented and promoted, especially when reporting on deaths of celebrities by suicide. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019086559.