Associations Between Motor Competence and Executive Functions in Children and Adolescents: A Systematic Review and Meta-analysis.

BACKGROUND: Motor competence and executive functions co-develop throughout childhood and adolescence, and there is emerging evidence that improvements in motor competence may have cognitive benefits in these populations. There is a need to provide a quantitative synthesis of the cross-sectional, longitudinal and experimental studies that have examined the association between motor competence and executive functions in school-aged youth. OBJECTIVES: The primary aim of our systematic review was to synthesise evidence of the association between motor competence and executive functions in school-aged children and adolescents (5-18 years). Our secondary aim was to examine key moderators of this association. METHODS: We searched the PubMed, PsycINFO, Scopus, Ovid MEDLINE, SPORTDiscus and EMBASE databases from inception up to 27 June 2023. We included cross-sectional, longitudinal and experimental studies that assessed the association between motor competence (e.g., general motor competence, locomotor skills, object control skills and stability skills) and executive functions (e.g., general executive functions, inhibition, working memory and cognitive flexibility) in children and adolescents aged 5-18 years. RESULTS: In total, 12,117 records were screened for eligibility, and 44 studies were included. From the 44 included studies, we meta-analysed 37 studies with 251 effect sizes using a structural equation modelling approach in the statistical program R. We found a small positive association (r = 0.18, [95% confidence interval (CI) 0.13-0.22]) between motor competence and executive functions. The positive associations were observed in cross-sectional (r = 0.17, [95% CI 0.13-0.22]), longitudinal (r = 0.15, [95% CI 0.03-0.28]) and experimental studies (r = 0.25, [95% CI 0.01-0.45]). We also found that general motor competence (r = 0.25, [95% CI 0.18-0.33]), locomotor (r = 0.15, [95% CI 0.09-0.21]), object control (r = 0.14, [95% CI 0.08-0.20]) and stability (r = 0.14, [95% CI 0.08-0.20]) skills were associated with executive functions. We did not find any moderating effects for participants' age on the associations between motor competence and executive functions. CONCLUSIONS: Our findings suggest a small-to-moderate positive association between motor competence and executive functions in children and adolescents. The small number of experimental studies included in this review support the assertion that interventions targeting children's motor competence may be a promising strategy to improve their executive functions; however, more research is needed to confirm these findings. Future studies should explore the underlying mechanisms linking motor competence and executive functions as their comprehension may be used to optimise future intervention design and delivery. PROSPERO REGISTRATION: CRD42021285134.

Is adherence to the 24-h movement guidelines associated with greater academic-related outcomes in children and adolescents? A systematic review and meta-analysis.

The purpose of this systematic review was to synthesise the evidence for the association of adherence to the 24-h movement guidelines with academic-related outcomes in children and adolescents. This systematic review was based on the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. PubMed, PsycINFO, Scopus, WOS, SPORTDiscus, and EMBASE were searched from their inception to 12 December 2023. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist was used to assess the risk of bias of included studies. In total, 4326 records were identified through database searches; 10 articles met the inclusion criteria and were included in this systematic review. There were eight cross-sectional studies and two longitudinal studies; the main academic-related outcomes were academic achievement and cognitive function. A small association between adherence to all three recommendations and academic achievement (k = 5, r = 0.17, 95% CI = 0.10-0.24, I2 = 49%) was found compared to those who did not adhere to any recommendations.   Conclusion: Findings from this systematic review and meta-analysis reveal a small association between adherence to all three recommendations and greater academic achievement in children and adolescents. Nevertheless, it is imperative to underscore the need for more studies to establish robust evidence underpinning this relationship.   Trial registration: PROSPERO (CRD42021295403). What is Known: • Regular physical activity, reduced screen time, and optimal sleep duration are independently associated with improved academic-related outcomes in children and adolescents. • The associations between adherence to the 24-h movement guidelines and academic-related outcomes in children and adolescents have not been quantitatively synthesised. What is New: • There is a small but positive association between adherence to all three recommendations of the 24-h movement guidelines and greater academic achievement in children and adolescents. • Further well-designed research is needed to focus on academic achievement, cognitive function and classroom behaviours in young individuals.

Association between meeting the 24-h movement guidelines and psychosocial health in children: A cross-sectional study.

OBJECTIVE: Emerging evidence suggests that meeting the 24-h movement guidelines is associated with optimal mental health. However, there remains some uncertainty regarding this association in children. Therefore, this study aimed to examine the association between meeting the 24-h movement guidelines and psychosocial health in children. METHODS: A cross-sectional study design was employed to investigate 2005 children aged 9-12 years from four districts of Shanghai, China. The 24-h movement behaviours were assessed using selected items from the Health Behaviour in School-aged Children (HBSC) survey questionnaire. Children's self-rated psychosocial health was evaluated using the Strengths or Difficulties Questionnaire (SDQ). Generalised Linear Models with the ordinal logistic module were employed to analyse the association between meeting the 24-h movement guidelines and psychosocial health. RESULTS: The overall prevalence of meeting all three 24-h movement recommendations was 10.2%. Among children, 7.9% of them exhibited abnormal total difficulties, with a notable difference between sex (boys: 11.2%, girls: 7.0%, p = 0.001). Meeting all three 24-h movement behaviour recommendations was associated with reduced total difficulties, emotional symptoms, conduct problems, hyperactivity and peer problems. Furthermore, a dose-response association was observed, indicating that meeting a greater number of 24-h movement behaviour recommendations was associated with enhanced psychosocial health, particularly in boys. CONCLUSION: The findings of this study highlight the positive association between meeting the 24-h movement guidelines and psychosocial health in children. Notably, meeting more of these recommendations was associated with a lower likelihood of experiencing psychosocial problems, with greater benefits observed in boys compared with girls.

24-hour movement behaviours and self-rated health in Chinese adolescents: a questionnaire-based survey in Eastern China.

Objective: Although much evidence has demonstrated the benefits of adhering to the 24-hour movement guidelines, little is known about their association with self-rated health in adolescents. The objective of this study was to explore the association between adherence to the 24-hour movement guidelines (i.e., physical activity, screen time, and sleep) and self-rated health among Chinese adolescents aged 10-17 ages. Methods: A convenient sample of 12 schools and their students were recruited for this cross-sectional study. Physical activity and screen time were assessed using a questionnaire based on the Health Behaviour in School-aged Children questionnaire, while sleep duration was used measured using the Pittsburgh Sleep Scale. Ordinal logistic regression was performed to examine the association between adherence to the 24-hour movement guidelines and self-rated health. Results: Adolescents who adhered to more guidelines contained in the 24-hour movement guidelines reported better self-rated health. A dose-response association was observed, with the odds ratio (OR) for adhering to all three = 11.26, 95% CI [4.82-26.35]; OR for meeting two = 1.62, 95% CI [1.25-2.12]; OR for meeting one = 1.16, 95% CI [0.98-1.38]) indicating a higher probability of better self-rated health with increasing adherence. Regarding adherence to specific combination of 24-hour movement guidelines, positive associations were found for adhering to all three recommendations (OR = 11.95, 95% CI [5.06-28.19]), only MVPA (OR = 4.96, 95% CI [2.82-8.72]), MVPA + screen time (OR = 5.50, 95% CI [3.02-9.99]), and MVPA + sleep (OR = 4.63, 95% CI [2.52-8.51]). Conclusion: This study provides evidence supporting the association between adherence to the 24-hour movement guidelines and better self-rated health among Chinese adolescents. Sufficient physical activity may be particularly important for promoting self-rated health in this population.

Eating habits matter for sleep difficulties in children and adolescents: A cross-sectional study.

Background: Sleep difficulties are a common sleep-related problem among children and adolescents. However, the association between eating habits and sleep difficulties has not been extensively studied. Therefore, this study aimed to investigate the relationship between eating habits and sleep difficulties in children and adolescents. Methods: This study utilized cross-sectional data from the 2013/2014 Health Behaviour in School-aged Children survey. A total of 213,879 young adolescents provided self-reported information on their weekday and weekend breakfast consumption, fruit and vegetable intake, sweet and soft drink consumption, and sleep difficulties. Covariates such as sex, age, family affluence, physical activity, and body mass index were also assessed. Multilevel generalized linear modelling was used to analyse the association between independent and dependent. Results were reported as odds ratios (OR) with 95% confidence intervals. Results: Of all study participants, approximately 50% were girls. Regression models indicated that more frequent breakfast consumption was associated with fewer sleep difficulties (e.g., consuming breakfast on weekdays for 5 days: OR = 1.49, 95% CI: 1.45-1.54). Fruit and vegetable consumption once a week or more was also linked to fewer sleep difficulties (all OR > 1.08, ≥ 1.07). In addition, consuming fewer sweets and soft drinks was generally associated with fewer sleep difficulties. Conclusion: This study provides evidence supporting the association between healthier eating habits and reduced sleep difficulties in children and adolescents. Future research using longitudinal or experimental designs is encouraged to confirm or negate these findings. Additionally, this study offers practical guidance for nutritional counselling professionals and sleep health promotion practitioners.

Reliability and validity of the Körperkoordinationstest Für Kinder in Chinese children.

Background: The Körperkoordinationstest Für Kinder (KTK) is a reliable and low-cost motor coordination test tool that has been used in several countries. However, whether the KTK is a reliable and valid instrument for use in Chinese children has not been assessed. Additionally, because the KTK was designed to incorporate locomotor, object control, and stability skills, and there is a lack of measurement tools that include stability skills assessment for Chinese children, the KTK's value and validity are worth discussing. Methods: A total of 249 primary school children (131 boys; 118 girls) aged 9-10 years from Shanghai were recruited in this study. Against the Test of Gross Motor Development-3 (TGMD-3), the concurrent validity of the KTK was assessed. We also tested the retest reliability and internal consistency of the KTK. Results: The test-retest reliability of the KTK was excellent (overall: r = 0.951; balancing backwards: r = 0.869; hopping for height: r = 0.918; jumping sideways: r = 0.877; moving sideways: r = 0.647). Except for the boys, the internal consistency of the KTK was higher than the acceptable level of Cronbach's α > 0.60 (overall: α = 0.618; boys: α = 0.583; girls: α = 0.664). Acceptable concurrent validity was found between the total scores for the KTK and TGMD-3 (overall: r = 0.420, p < 0.001; boys: r = 0.411, p < 0.001; girls: r = 0.437, p < 0.001). Discussion: The KTK is a reliable instrument for assessing the motor coordination of children in China. As such, the KTK can be used to monitor the level of motor coordination in Chinese children.

Physical education, muscle strengthening exercise, sport participation and their associations with screen time in adolescents.

Background/Objective: Physical activity (PA) has been suggested to reduce screen time. This study aimed to explore the associations of physical education (PE), muscle-strengthening exercise (MSE), and sport participation with screen time. Methods: A multi-cluster sampling design was used to select 13,677 school-attending adolescents that participated in the Youth Risk Behavior Surveillance 2019 survey. Adolescents self-reported their frequency of PE attendance, participations in MSE, sport participation and hours for screen time. Additionally, participants provided demographic information including sex, age, race, grade, and weight status. Results: Collectively, there were beneficial associations between participating in MSE for 4 (OR = 1.31, CI: 1.02-1.68), 5 (OR = 1.65, CI: 1.31-2.08), 6 (OR = 2.23, CI: 1.47-3.36), 7 (OR = 1.62, CI: 1.30-2.01) days and video or computer game hours. Similarly, beneficial associations between participating in 1 team sport (OR = 1.23, CI: 1.06-1.42), 2 team sports (OR = 1.61, CI: 1.33-1.95), 3 or more team sports (OR = 1.45, CI: 1.16-1.83) and video or computer game hours were observed. Participating in 1 team sport (OR = 1.27, CI: 1.08-1.48), 2 teams sport (OR = 1.41, CI: 1.09-1.82), 3 or more team sport (OR = 1.40, CI: 1.03-1.90) also increased the odds for meeting guidelines for television viewing hours. Only 2 days of PE attendance (OR = 1.44, CI: 1.14-1.81) was significantly associated with video or computer game hours. Conclusion: The promotion of sports participation appears to be an important component for reducing excess screen time in adolescents. Further, MSE may have beneficial effects on reducing time spent on the computer and playing video games.

Investigating the direct and indirect effects of a school-based leadership program for primary school students: Rationale and study protocol for the 'Learning to Lead' cluster randomised controlled trial.

BACKGROUND: Leadership is a valuable skill that can be taught in school, and which may have benefits within and beyond the classroom. Learning to Lead (L2L) is a student-led, primary school-based leadership program whereby older 'peer leaders' deliver a fundamental movement skills (FMS) program to younger 'peers' within their own school. AIM: The aims of the study are to determine the efficacy of a peer-led FMS intervention on: (i) peer leaders' (aged 10 to 12 years) leadership effectiveness (primary outcome), leadership self-efficacy, well-being, and time on-task in the classroom; (ii) peers' (aged 8 to 10 years) physical activity levels, actual and perceived FMS competency, cardiorespiratory fitness, muscular power, and executive functioning; and (iii) teachers' (referred to as 'school champions') work-related stress and well-being. METHOD: L2L will be evaluated using a two-arm parallel group cluster randomised controlled trial. Twenty schools located within a two-hour drive of the University of Newcastle, Australia will be recruited. We will recruit 80 students (40 peer leaders and 40 peers) from each school (N = 1,600). L2L will be implemented in three phases: Phase 1 -school champions' training via a professional learning workshop; Phase 2 -school champions' delivery of leadership lessons to the peer leaders; and Phase 3 -peer leaders' delivery of the FMS program to their younger peers. The FMS program, consisting of 12 x 30-minute lessons, will be delivered over the course of one school term (10 weeks). Study outcomes will be assessed at baseline (between mid-March to June, Terms 1 and 2), intervention end (mid-August to September, Term 3), and follow-up (November to mid-December, Term 4. This trial was prospectively registered on the Australian New Zealand Clinical Trials Registry (ANZCTR); registration number: ACTRN12621000376842.

Public Health Concern on Sedentary Behavior and Cardiovascular Disease: A Bibliometric Analysis of Literature from 1990 to 2022.

Background and Objectives: Cardiovascular disease is a long-term threat to global public health security, while sedentary behavior is a modifiable behavior among cardiovascular risk factors. This study aimed to analyze the peer-reviewed literature published globally on sedentary behavior and cardiovascular disease (SB-CVD) and identify the hotspots and frontiers within this research area. Materials and Methods: Publications on SB-CVD from 1990 to 2022 were retrieved from the Web of Science Core Collection. CiteSpace and VOSviewer were applied to perform bibliometric and knowledge mapping visualization analyses. Results: A total of 2071 publications were retrieved, presenting a gradual growing trend. Authors from the USA topped the list with 748 (36.12%), followed by authors from England (373, 18.01%) and Australia (354, 17.09%). The University of Queensland, Australia, led with 95 (4.5%) publications. The top five active authors were all from Australia, while Dunstan D and Owen N published the most documents (56, 2.7%). A total of 71.27% of the publications received funding, and the United States Department of Health and Human Services provided 363 (17.53%) grants. Public Environmental Occupational Health (498, 24.05%), Sport Sciences (237, 11.44%), and Cardiac Cardiovascular Systems (212, 10.24%) were the three most popular disciplines, while PLOS One (96, 4.64%) and BMC Public Health (88, 4.25%) were the two most popular journals. Investigations within the SB-CVD research area addressed the entire lifespan, the most popular type of research was the epidemiological study, and the accelerometer was the primary instrument for measuring sedentary behavior. In terms of variables, physical activity and sedentary behavior were the dominant lifestyle behaviors, while obesity and hypertension were common health problems. Occupational physical activity and guidelines are at the frontier and are currently in the burst stage. Conclusions: The last three decades have witnessed the rapid development of the SB-CVD research area, and this study provided further research ideas for subsequent investigations.

Reliability of International Fitness Scale (IFIS) in Chinese Children and Adolescents.

BACKGROUND AND OBJECTIVES: It has previously been shown that the International Fitness Scale (IFIS) is a reliable and valid instrument when used in numerous regions and subgroups, but it remains to be determined whether the IFIS is a reliable instrument for use with Chinese children and adolescents. If the reliability of the IFIS can be verified, populational surveillance and monitoring of physical fitness (PF) can easily be conducted. This study aimed to test the reliability of the IFIS when used with Chinese children and adolescents. METHODS: The convenience sampling method was used to recruit study participants. In total, 974 school-aged children and adolescents between 11 and 17 years of age were recruited from three cities in Southeast China: Shanghai, Nanjing and Wuxi. The study participants self-reported demographic data, including age (in years) and sex (boy or girl). The participants completed the questionnaire twice within a two-week interval. RESULTS: A response rate of 95.9% resulted in a sample of 934 participants (13.7 ± 1.5 years, 47.4% girls) with valid data. On average, the participants were 13.7 ± 1.5 years of age. The test-retest weighted kappa coefficients for overall fitness, cardiorespiratory fitness, muscle fitness, speed and agility and flexibility were 0.52 (Std. errs. = 0.02), 0.51 (Std. errs. = 0.02), 0.60 (Std. errs. = 0.02), 0.55 (Std. errs. = 0.02) and 0.55 (Std. errs. = 0.02), respectively. CONCLUSIONS: The International Fitness Scale was found to have moderate reliability in the assessment of (self-reported) physical fitness in Chinese children and adolescents. In the future, the validity of the IFIS should be urgently tested in Chinese subgroup populations.

Associations of 24-Hour Movement Behavior with Depressive Symptoms and Anxiety in Children: Cross-Sectional Findings from a Chinese Sample.

This study examined the associations between adherence to 24-hour movement behavior guidelines (24-HMB) and the mental-health-related outcomes of depressive symptoms and anxiety in Chinese children. Data on movement behavior from 5357 children (4th and 5th grades), including physical activity, recreational screen time and sleep, were self-reported using the Health Behavior School-Aged Children Survey. Depressive symptoms and anxiety were self-reported using the Chinese version of the nine-item Patient Health Questionnaire and the Generalized Anxiety Disorder Scale, respectively. Depressive symptoms and anxiety were treated as categorical variables. Only 3.2% of the participants met physical activity, screen time, and sleep 24-HMB guidelines. Ordinal logistic regressions showed that, compared with participants who met the 24-HMB guidelines, participants who met none (odds ratio (OR) = 2.62, 95% CI: 1.76-3.90) or any one of the guidelines (OR = 1.88, 95% CI: 1.27-2.77) had higher odds of depressive symptoms. Similarly, there were higher odds of anxiety in participants who met none (OR = 2.32, 95% CI: 1.45-3.70) or any one of the recommendations (OR = 1.62, 95% CI: 1.03-2.57) compared with participants who met all the 24-HMB guidelines. Meeting the 24-HMB guidelines is associated with better mental-health-related outcomes in Chinese children. Because of the low prevalence of Chinese children meeting the 24-HMB recommendations, the present findings highlight the need to encourage children to regularly engage in physical activity, decrease their time spent sitting, and improve their sleep patterns.

Association between physical education classes and physical activity among 187, 386 adolescents aged 13-17 years from 50 lowand middle-income countries

Abstract Objective: This study aimed to examine the association between physical education classes and PA among adolescents from 50 lowand middle-income countries (LMICs). Methods: A self-reported questionnaire from the Global School-based Student Survey (GSHS) was used to collect information on participation frequency of physical education classes and being physically active over the last week, as well as other control variables (e.g., sex, age, country, sedentary behavior). Multivariable logistic regression and a pooled meta-analysis were performed to explore the association and compared country-wise differences. Results: Included adolescents aged from 13 to 17 years (n = 187,386, %boys = 51.7; mean age = 14.6 years), the prevalence of sufficient PA (meeting the PA guidelines) was 14.9%. The prevalence of 5 days or more to engage in physical education classes was 16.5%. Compared with adolescents who had 0 days for physical education classes, higher participation frequency was more likely related to sufficient PA (OR: 1 day = 1.34, 2 days = 1.66, 3 days = 1.67, 4 days = 1.79, 5 days or more = 2.46), these findings were also observed in both sexes. A moderate inconsistency on the association across the included countries was found (I2 = 53%, p < 0.01), although the pooled OR was 1.50 (95% CI: 1.36-1.65). Conclusions: Participating in more physical education classes may be an effective approach to increase physical activity levels among adolescents in LMICs. However, promoting physical activity levels among adolescents in LMICs through physical education classes should consider more country-specific factors.

Association between physical education classes and physical activity among 187,386 adolescents aged 13-17 years from 50 low- and middle-income countries.

OBJECTIVE: This study aimed to examine the association between physical education classes and PA among adolescents from 50 low- and middle-income countries (LMICs). METHODS: A self-reported questionnaire from the Global School-based Student Survey (GSHS) was used to collect information on participation frequency of physical education classes and being physically active over the last week, as well as other control variables (e.g., sex, age, country, sedentary behavior). Multivariable logistic regression and a pooled meta-analysis were performed to explore the association and compared country-wise differences. RESULTS: Included adolescents aged from 13 to 17 years (n=187,386, %boys=51.7; mean age=14.6 years), the prevalence of sufficient PA (meeting the PA guidelines) was 14.9%. The prevalence of 5 days or more to engage in physical education classes was 16.5%. Compared with adolescents who had 0 days for physical education classes, higher participation frequency was more likely related to sufficient PA (OR: 1 day=1.34, 2 days=1.66, 3 days=1.67, 4 days=1.79, 5 days or more=2.46), these findings were also observed in both sexes. A moderate inconsistency on the association across the included countries was found (I2=53%, p<0.01), although the pooled OR was 1.50 (95% CI: 1.36-1.65). CONCLUSIONS: Participating in more physical education classes may be an effective approach to increase physical activity levels among adolescents in LMICs. However, promoting physical activity levels among adolescents in LMICs through physical education classes should consider more country-specific factors.

Preference for daily versus on-demand pre-exposure prophylaxis for HIV and correlates among men who have sex with men: the China Real-world Oral PrEP Demonstration study.

INTRODUCTION: This study explores the preference for daily versus on-demand pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in developing countries when both regimens are available. METHODS: From 11 December 2018 to 19 October 2019, we recruited MSM for an open-label real-world PrEP demonstration study in four major cities in China. Subjects selected their preferred PrEP (oral tenofovir/emtricitabine) regimen (daily vs. on-demand) at recruitment and underwent on-site screening before initiation of PrEP. We used logistic regression to assess preference for daily PrEP and correlates. RESULTS: Of 1933 recruited MSM, the median age was 29 years, 7.6% was currently married to or living with a female; the median number of male sexual partners was four and 6.1% had used post-exposure prophylaxis (PEP) in the previous six months. HIV infection risk was subjectively determined as very high (>75%) in 7.0% of subjects, high (50% to 75%) in 13.3%, moderate (25% to 49%) in 31.5% and low or none (0% to 24%) in 48.1%. On average, participants preferred on-demand PrEP over daily PrEP (1104 (57.1%) versus 829 (42.9%)) at recruitment. In multivariable analysis, currently being married to or living with a female was associated with 14.6 percentage points lower preference for daily PrEP (marginal effect = -0.146 [95% CI: -0.230, -0.062], p = 0.001); whereas the number of male sexual partners (marginal effect = 0.003 [95% CI: 0.000, 0.005], p = 0.034) and a subjective assessment of being very high risk of HIV infection (vs. low and no risk, marginal effect size = 0.105 [95% CI: 0.012, 0.198], p = 0.027) were associated with increased preference for daily versus on-demand PrEP. Among the 1933 potential participants, 721 (37.3%) did not attend the subsequent on-site screening. Lower-income, lower education level, lower subjective expected risk of HIV infection risk and younger age positively correlated with the absence of on-site screening. CONCLUSIONS: MSM in China prefer both daily and on-demand PrEP when both regimens are provided free. Social structural factors and subjective risk of HIV infection have significant impacts on PrEP preference and use. The upcoming national PrEP guideline should consider incorporating both regimens and the correlates to help implement PrEP in China.

Sedentary Behavior Research in the Chinese Population: A Systematic Scoping Review.

Background: The negative effects of sedentary behavior (SB) on public health have been extensively documented. A large number of studies have demonstrated that high prevalence of SB is a critical factor of all-cause mortality. Globally, the frequency of SB research has continued to rise, but little is known about SB in the Chinese population. Therefore, this review was conducted to scope the research situation and to fill the gaps related to the effects of SB in the Chinese population. Methods: Using a scoping review based on York methodology, a comprehensive search of published journal articles and grey literature was carried out through 12 databases. The literature research was conducted by two authors in July 2019, and included journal articles that targeted on the Chinese population were published between 1999 and 2019. The two authors screened the records independently and included those research topics related to SB in the Chinese population. Results: The number of included studies increased from 1 to 29 per year during the analyzed period, during which, a remarkable climb happened from 8 in 2013 to 19 in July 2019. Out of the 1303 screened studies, a total of 162 studies (81 English and 81 Chinese journal articles) met the inclusion criteria in this review. Most of the included studies (66.0%) reported the overall estimated prevalence of SB, in which, 43.2% of studies reported the average time of SB, and 40.0% of studies reported the cutoff point of SB. Besides this, 54.9% and 23.5% of studies focused on the outcomes and correlates/determinants of SB, and the proportions of studies based on testing the validation of measurement tools and on interventions were 3.7% and 4.9%, respectively. Nearly all of the reviewed articles used data from cross-sectional studies (75.9%) and longitudinal studies (13.6%), while intervention trials are less developed. The majority of the studies (64.8%) used self-reported surveys, and only 3.7% studies used device-based measurement tools. Furthermore, 35.8% of the included studies were focused on children and adolescents, while only a few studies investigated infants/toddlers and older adults. Both female and male were examined in most studies, and non-clinical populations were investigated in the context of SB in a relatively large number of studies. Conclusions: The number of research articles on SB in the Chinese population published per year has increased year by year, indicating a growing interest in this research area. More studies using population subgroup samples are needed, particularly among infants/toddlers, older adults, and clinical populations. To provide stronger evidence of the determinants and outcomes of SB, longitudinal studies using device-based measures of SB are required.

Group consensus control for networked multi-agent systems with communication delays.

This paper investigates group consensus problems in networked multi-agent systems (NMAS) with communication delays. Based on the sed state prediction scheme, the group consensus control protocol is designed to compensate the communication delay actively. In light of algebraic graph theories and matrix theories, necessary and(or) sufficient conditions of group consensus with respect to a given admissible control set are obtained for the NMAS with communication delays under mild assumptions. Finally, simulations are performed to demonstrate the effectiveness of the theoretical results.

Annexin A2 as a target endothelial cell membrane autoantigen in Behçet's disease.

Cell membrane proteins are believed to play a critical role in the pathogenesis of autoimmune diseases. However, few membrane autoantigens have been linked with Behçet's disease. Here, a cell-chip was performed to identify autoantibody target cells, and the suspected autoantigens were detected using immunoblotting. The amino acid sequences of the detected proteins were determined using LC-MALDI-TOF/TOF. Putative proteins were recombinantly expressed and purified, and a corresponding ELISA was developed and clinically validated using real clinical samples. It was found that a 36-kDa membrane protein--annexin A2--was detected in approximately one-third of the patients' blood circulation. The immunohistochemistry results showed that annexin A2 was highly expressed in vascular endothelial cells. Moreover, vascular involvement was significantly higher in the anti-annexin A2 antibody-positive group versus the anti-annexin A2 antibody-negative group among all the clinical samples analyzed, indicating that annexin A2 is a novel endothelial cell membrane antigen involved in Behçet's disease.