Cadmium Sulfide Nanoparticles: Preparation, Characterization, and Biomedical Applications.

Cadmium sulfide nanoparticles (CdS NPs) have been employed in various fields of nanobiotechnology due to their proven biomedical properties. They are unique in their properties due to their size and shape, and they are popular in the area of biosensors, bioimaging, and antibacterial and anticancer applications. Most CdS NPs are generally synthesized through chemical, physical, or biological methods. Among these methods, biogenic synthesis has attracted more attention due to its high efficiency, environmental friendliness, and biocompatibility features. The green approach was found to be superior to other methods in terms of maintaining the structural characteristics needed for optimal biomedical applications. The size and coating components of CdS NPs play a crucial role in their biomedical activities, such as anticancer, antibacterial, bioimaging, and biosensing applications. CdS NPs have gained significant interest in bioimaging due to their desirable properties, including good dispersion, cell integrity preservation, and efficient light scattering. Despite these, further studies are necessary, particularly in vivo studies to reduce NPs' toxicity. This review discusses the different methods of synthesis, how CdS NPs are characterized, and their applications in the biomedical field.

Results from the Singapore 2022 report card on physical activity for children and adolescents.

Background: While it has been established that physical activity (PA) is key to promote overall health and well-being, insufficient physical activity among children and adolescents is a global problem, including Singapore. It is important to understand the local PA landscape among children and adolescents to decrease surveillance gaps and identify areas for improvement in promoting PA. The present article provides an overview of the development of the 2022 Active Healthy Kids Singapore Report Card and the results, as well as underscore limitations and gaps in the available evidence related to PA among children and adolescents in Singapore. Methods: Following the Global Matrix 4.0, the available data between July 2010 to July 2020 was synthesized for all 10 indicators by the work group and reviewed by a panel of experts. Data sources included published scientific articles, government and non-government reports, national surveys, and unpublished data from on-going research studies. Where possible, grades were informed by nationally representative surveys or large-scale longitudinal studies. Results: The grades assigned were: Overall Physical Activity (C-), Organized Sport and Physical Activity (B-), Active Play (C-), Active Transportation (C), Sedentary Behaviours (C-), Physical Fitness (Incomplete), Family and Peers (C-), School (Incomplete), Community and Environment (A+), Government (B). Conclusion: This is the first comprehensive evaluation of PA among children and adolescents in Singapore. It provides baseline grades valuable for future comparison. It also illustrates gaps in the existing evidence which can inform future surveillance, facilitate international comparisons and enable global efforts in promoting physical activity.

Report card grades on physical activity for children and adolescents from 18 Asian countries: Patterns, trends, gaps, and future recommendations.

Background: Physical inactivity is a persistent and worsening population health concern in Asia. Led by the Active Healthy Kids Global Alliance, Global Matrix (GM) initiative provides an opportunity to explore how regional and cultural differences across 18 Asian countries relate to physical activity (PA) participation among children and adolescents. Objectives: To synthesize evidence from the GM2.0 to GM4.0 (2016-2022) in Asian countries. Methods: Report Card grades on behavioral/individual and sources of influence indicators were reported from 18 Asian countries. Letter grades were converted into numerical values for quantitative analyses. Based on this, cross-sectional and longitudinal analyses were conducted to investigate patterns and trends. Qualitative evidence synthesis was performed based on Report Card grades and published papers to identify gaps and suggest future recommendations. Results: In total, 18 countries provided grades for at least one round of GM, 12 countries provided grades for at least two rounds, and seven countries provided grades for all three GMs. Of possible grades, 72.8%, 69.2%, and 76.9% of the grades were assigned from GM 2.0 to GM 4.0, respectively. In terms of the Report Card grades, there was a slight decrease in behavioral/individual indicators from "D+" in GM 2.0 to "D-" in GM 3.0 but this reverted to "D" in GM 4.0. For the sources of influence, a "C" grade was given in all three rounds of GM. Longitudinal observation of seven Asian countries that provided grades in all three rounds of GM revealed that grades are generally stable for all indicators with some country-specific fluctuations. In future GM initiatives and research, considerations should be made to provide more accurate and rich data and to better understand contextual challenges in evaluating certain indicators such as Active Transportation, Active Play, and Physical Fitness in particular. Further, macro level factors such as socioeconomic/cultural disparities and gender-specific barriers, ideology, or climate change should also be proactively considered in future research as these factors are becoming increasingly relevant to indicators of GM and United Nation's Sustainable Development Goals. Conclusions: Participation from Asian countries in GM has increased over the years, which demonstrates the region's enthusiasm, capacity, and support for global PA promotion efforts. The efforts to promote a physically active lifestyle among children and adolescents should be a collective interest and priority of the Asia region based on the gaps identified in this paper.

The longitudinal association between early-life screen viewing and abdominal adiposity-findings from a multiethnic birth cohort study.

IMPORTANCE: Screen viewing in adults has been associated with greater abdominal adiposity, with the magnitude of associations varying by sex and ethnicity, but the evidence is lacking at younger ages. We aimed to investigate sex- and ethnic-specific associations of screen-viewing time at ages 2 and 3 years with abdominal adiposity measured by magnetic resonance imaging at age 4.5 years. METHODS: The Growing Up in Singapore Towards healthy Outcomes is an ongoing prospective mother-offspring cohort study. Parents/caregivers reported the time their child spent viewing television, handheld devices, and computer screens at ages 2 and 3 years. Superficial and deep subcutaneous and visceral abdominal adipose tissue volumes were quantified from magnetic resonance images acquired at age 4.5 years. Associations between screen-viewing time and abdominal adipose tissue volumes were examined by multivariable linear regression adjusting for confounding factors. RESULTS: In the overall sample (n = 307), greater total screen-viewing time and handheld device times were associated with higher superficial and deep subcutaneous adipose tissue volumes, but not with visceral adipose tissue volumes. Interactions with child sex were found, with significant associations with superficial and deep subcutaneous and visceral adipose tissue volumes in boys, but not in girls. Among boys, the increases in mean (95% CI) superficial and deep subcutaneous and visceral adipose tissue volumes were 24.3 (9.9, 38.7), 17.6 (7.4, 27.8), and 7.8 (2.1, 13.6) mL per hour increase in daily total screen-viewing time, respectively. Ethnicity-specific analyses showed associations of total screen-viewing time with abdominal adiposity only in Malay children. Television viewing time was not associated with abdominal adiposity. CONCLUSION: Greater total screen-viewing time (and in particular, handheld device viewing time) was associated with higher abdominal adiposity in boys and Malay children. Additional studies are necessary to confirm these associations and to examine screen-viewing interventions for preventing excessive abdominal adiposity and its adverse cardiometabolic consequences.

24-hour movement behaviour profiles and their transition in children aged 5.5 and 8 years - findings from a prospective cohort study.

BACKGROUND: Time spent in movement behaviours, including physical activity (PA), sedentary behaviour (SB) and sleep, across the 24-h day may have distinct health consequences. We aimed to describe 24-h movement behaviour (24 h-MB) profiles in children and how profile membership changed from age 5.5 to 8 years. METHODS: Children in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort were asked to wear an accelerometer (ActiGraph-GT3X+) on their wrist for seven consecutive days at ages 5.5 and 8 years to measure 24 h-MB patterns. Time spent in night sleep, inactivity (proxy for SB), light PA, moderate PA (MPA), and vigorous PA (VPA) per day were calculated using the R-package GGIR 2.0. Using latent profile analyses (n = 442) we identified 24 h-MB profiles, which were given animal names to convey key characteristics. Latent transition analyses were used to describe the profile membership transition from ages 5.5 to 8 years. Associations with sex and ethnicity were examined. RESULTS: We identified four profiles, "Rabbits" (very high-MPA/VPA, low-inactivity and average-night-sleep), "Chimpanzees" (high-MPA, low-inactivity and average-night-sleep), "Pandas" (low-PA, high-inactivity and high-night-sleep) and "Owls" (low-PA, high-inactivity and low-night-sleep), among children at both time points. At ages 5.5 and 8 years, the majority of children were classified into profiles of "Chimpanzees" (51 and 39%, respectively) and "Pandas" (24 and 37%). Half of the sample (49%), particularly "Rabbits", remained in the same profile at ages 5.5 and 8 years: among children who changed profile the predominant transitions occurred from "Chimpanzees" (27%) and "Owls" (56%) profiles to "Pandas". Sex, but not ethnicity, was associated with profile membership: compared to girls, boys were more likely to be in the "Rabbits" profile (adjusted OR [95% CI]: 3.6 [1.4, 9.7] and 4.5 [1.8, 10.9] at ages 5.5 and 8 years, respectively) and less likely to be in the "Pandas" profile (0.5 [0.3, 0.9] and 0.4 [0.2, 0.6]) at both ages. CONCLUSIONS: With increasing age about half the children stayed in the same of four 24 h-MB profiles, while the predominant transition for the remaining children was towards lower PA, higher inactivity and longer sleep duration. These findings can aid development and implementation of public health strategies to promote better health. STUDY REGISTRATION: This study was registered on 4th August 2010 and is available online at ClinicalTrials.gov: NCT01174875 .

Socio-demographic and maternal predictors of adherence to 24-hour movement guidelines in Singaporean children.

PURPOSE: Integrated 24-Hour Movement Guidelines provide specific recommendations on screen viewing (SV), moderate-to-vigorous physical activity (MVPA) and sleep to improve health of children and youth. However, few studies have examined whether these guidelines are met in young children, particularly in Asia. We evaluated adherence to integrated and individual guidelines and its predictors in 5.5-year-old Singaporean children. METHODS: Growing Up in Singapore towards Healthy Outcomes (GUSTO) is a mother-offspring birth cohort study. At age 5.5 years, child SV was reported by parents. Movement behaviours (MBs) were measured continuously using wrist-worn accelerometers over 7 consecutive days and nights. For accelerometer data including ≥3 days with ≥16 h/day we estimated mean (±SD) daily MVPA, SV and nighttime sleep duration across the week. Adherence to integrated (Canadian/Australian) guidelines was defined as meeting all individual guidelines: ≥60 min of MVPA/day, ≤2 h of screen time/day, and 9-11 h of sleep/night. Socio-demographic and maternal predictors collected at pregnancy enrolment and at 26-28 weeks' gestation were examined by multivariable logistic regression. RESULTS: Of 864 children followed up age 5.5 years, 547 (63.3%) had both valid ActiGraph and questionnaire data (51.7% boys and 58.3% Chinese ethnicity). Children averaged 101.9 (± 88.7) min/day SV, 67.3 (± 23.7) min/day MVPA and 480.6 (± 57.2) min/night sleep. Few children met integrated guidelines. Specifically, the proportions of children who met none, SV, MVPA, sleep and integrated guidelines were 11.2, 70.2, 59.6, 13.7 and 5.5%, respectively. Multivariable analysis showed that maternal activity and television (TV) viewing were associated with meeting integrated guidelines (insufficiently vs. highly active (OR [95% CI]): 0.11 [0.01, 0.95]; 2-3 vs. ≥ 3 h TV: 3.52 [1.02, 12.22]). Examining higher adherence to individual guidelines, Chinese ethnicity, younger maternal age and lower maternal TV and sleep time were associated with greater SV; male sex, Malay ethnicity, higher birth order and higher maternal activity level were associated with greater MVPA; and older maternal age was associated with adherence to sleep guideline. CONCLUSIONS: Beyond individual behaviours, consideration of the full spectrum of MBs may be important to improve children's health. However, few Singaporean children adhere to integrated 24-h movement guidelines. Maternal behaviours as early as during pregnancy could be important targets for future interventions aiming to promote these MBs in children.

Screen viewing behavior and sleep duration among children aged 2 and below.

BACKGROUND: Few studies have investigated the association between screen viewing (SV) and sleep duration among young children. This study aims to examine the association between total and device-specific SV and sleep duration among children aged 2 and below. METHODS: We conducted a cross-sectional study of 714 Singaporean children aged 2 years and below. Parents were recruited during routine well-child clinic visits from two national polyclinics. In Singapore, all parents visit well-child clinics with their children at regular intervals for routine check-ups and vaccinations. Socio-demographic characteristics, duration of total and device-specific SV, and sleep duration were reported by parents via interviewer-administered questionnaires. Multiple linear regression analysis was used to assess associations between various types of SV and sleep duration, adjusted for socio-demographic variables. Due to significant interaction between SV and age, stratified analyses for children aged less than 6 months and those aged 7-24 months were performed. RESULTS: The prevalence of daily SV among children was 53.1%; 28.3% in children up to 6 months and 73.8% in children aged 7 to 24 months. TV viewing was reported for 44.3% of all children and mobile device SV for 30.1%. Children's average sleep duration was 13.9 (SD = 3.5) hours daily and younger children had longer sleep duration than older ones (up to 6 months: mean = 15.6 h, SD = 3.9; 7-24 months: mean = 12.4 h, SD = 2.2; P < 0.01). In the regression analysis among all children, each 1 h per day increment in total SV was significantly associated with 0.26 h shorter sleep duration with similar significant associations for TV (ß = - 0.28 h, 95%CI: -0.50, - 0.06) and mobile devices (ß = - 0.35 h, 95%CI: -0.61, - 0.09). Stratified analysis revealed significantly greater reductions in sleep with higher SV among children aged 6 months and below (ß = - 0.73 h, 95%CI: -1.12, - 0.34), while associations were weaker in older children (ß = - 0.13 h, 95% CI: -0.24, - 0.01). CONCLUSIONS: This study provides evidence for a substantial association between longer SV and shorter sleep duration among very young children. These associations appeared stronger among children aged 6 months and below as compared with those aged 7 to 24 months. Further studies are warranted to confirm our findings.

Predictors of screen viewing time in young Singaporean children: the GUSTO cohort.

BACKGROUND: Higher screen viewing time (SVT) in childhood has been associated with adverse health outcomes, but the predictors of SVT in early childhood are poorly understood. We examined the sociodemographic and behavioral predictors of total and device-specific SVT in a Singaporean cohort. METHODS: At ages 2 and 3 years, SVT of 910 children was reported by their parents. Interviewer-administered questionnaires assessed SVT on weekdays and weekends for television, computer, and hand-held devices. Multivariable linear mixed-effect models were used to examine the associations of total and device-specific SVT at ages 2 and 3 with predictors, including children's sex, ethnicity, birth order, family income, and parental age, education, BMI, and television viewing time. RESULTS: At age 2, children's total SVT averaged 2.4 ± 2.2 (mean ± SD) hours/day, including 1.6 ± 1.6 and 0.7 ± 1.0 h/day for television and hand-held devices, respectively. At age 3, hand-held device SVT was 0.3 (95% CI: 0.2, 0.4) hours/day higher, while no increases were observed for other devices. SVT tracked moderately from 2 to 3 years (r = 0.49, p < 0.0001). Compared to Chinese children, Malay and Indian children spent 1.04 (0.66, 1.41) and 0.54 (0.15, 0.94) more hours/day watching screens, respectively. Other predictors of longer SVT were younger maternal age, lower maternal education, and longer parental television time. CONCLUSIONS: In our cohort, the main predictors of longer children's SVT were Malay and Indian ethnicity, younger maternal age, lower education and longer parental television viewing time. Our study may help target populations for future interventions in Asia, but also in other technology-centered societies. TRIAL REGISTRATION: This ongoing study was first registered on July 1, 2010 on NCT01174875 as. Retrospectively registered.

Biguanide chitosan microneedles with cell-free DNA scavenging ability for psoriasis therapy.

High levels of cell-free DNA (cfDNA) induce psoriasis. Currently, the treatment of psoriasis has the disadvantages of penetration difficulty, suppression of normal immunity, and skin irritation. In this study, biguanide chitosan microneedles (BGC-MNs) were prepared to treat psoriasis by removing cfDNA from the dermis through the skin barrier. The effects of chitosan with different bisguanidine contents on DNA-binding capacity, biocompatibility, and inflammation inhibition were compared, revealing that chitosan containing 20% bisguanidine (BGC2) was found to have the best overall performance. In vitro, BGC2 effectively cleared cfDNA and inhibited the production of inflammatory factors. BGC-MN made from BGC2 had good mechanical and solubility properties. In vivo, BGC-MNs cleared cfDNA, reduced the level of inflammatory factors in the dermis, and exerted a good therapeutic effect on mice with psoriasis. These results suggested that BGC-MNs provided a new approach to treating psoriasis in terms of scavenging cfDNA and exerting anti-inflammatory effects.

Rationale, Design, and Baseline Characteristics of Participants in the Health@NUS mHealth Augmented Cohort Study Examining Student-to-Work Life Transition: Protocol for a Prospective Cohort Study.

BACKGROUND: Integration of mobile health data collection methods into cohort studies enables the collection of intensive longitudinal information, which gives deeper insights into individuals' health and lifestyle behavioral patterns over time, as compared to traditional cohort methods with less frequent data collection. These findings can then fill the gaps that remain in understanding how various lifestyle behaviors interact as students graduate from university and seek employment (student-to-work life transition), where the inability to adapt quickly to a changing environment greatly affects the mental well-being of young adults. OBJECTIVE: This paper aims to provide an overview of the study methodology and baseline characteristics of participants in Health@NUS, a longitudinal study leveraging mobile health to examine the trajectories of health behaviors, physical health, and well-being, and their diverse determinants, for young adults during the student-to-work life transition. METHODS: University students were recruited between August 2020 and June 2022 in Singapore. Participants would complete biometric assessments and questionnaires at 3 time points (baseline, 12-, and 24-month follow-up visits) and use a Fitbit smartwatch and smartphone app to continuously collect physical activity, sedentary behavior, sleep, and dietary data over the 2 years. Additionally, up to 12 two-week-long bursts of app-based ecological momentary surveys capturing lifestyle behaviors and well-being would be sent out among the 3 time points. RESULTS: Interested participants (n=1556) were screened for eligibility, and 776 participants were enrolled in the study between August 2020 and June 2022. Participants were mostly female (441/776, 56.8%), of Chinese ethnicity (741/776, 92%), undergraduate students (759/776, 97.8%), and had a mean BMI of 21.9 (SD 3.3) kg/m2, and a mean age of 22.7 (SD 1.7) years. A substantial proportion were overweight (202/776, 26.1%) or obese (42/776, 5.4%), had indicated poor mental well-being (World Health Organization-5 Well-Being Index ≤50; 291/776, 37.7%), or were at higher risk for psychological distress (Kessler Psychological Distress Scale ≥13; 109/776, 14.1%). CONCLUSIONS: The findings from this study will provide detailed insights into the determinants and trajectories of health behaviors, health, and well-being during the student-to-work life transition experienced by young adults. TRIAL REGISTRATION: ClinicalTrials.gov NCT05154227; https://clinicaltrials.gov/study/NCT05154227. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/56749.

Systemic lupus erythematosus presented as extensive longitudinal myelitis.

BACKGROUND: longitudinal myelitis (LM) is defined by the continuous lesion of more than four spinal cord segments. LM is a rare variant of acute transverse myelitis and it frequently presented poor responses to immunomodulatory therapy, which resulted in severe and disabling sequelae. We reported a case of acute longitudinal myelitis involving extensive lesions from cervical spinal cord to conus medullaris caused by newly diagnosed SLE. CASE REPORT: A 39 years old man who was previously healthy presented to our hospital due to acute urinary retention with progressive lower limb weakness for a week. Brisk deep tendon reflexes in upper limbs and decreased reflexes in lower limbs were noted on admission. The pin-prick, vibration, and light touch sensations were decreased in the lower limbs. Spinal MRI sagittal view showed an T2WI bright up mass in the spinal cord below C3/4 level with extension to conus medullaris. He was diagnosed SLE based on ARA criteria. After ruling out mimics including NMO and MS, SLE with LM explained what happened to him . CONCLUSION: Given the poor prognosis of SLE with LM, which resulted in severe and disabling sequelae. More comprehensive understand of the disease course, real mechanisms and treatment strategy are needed.

Multifunctional Self-Assembled Peptide Hydrogels for Biomedical Applications.

Self-assembly is a growth mechanism in nature to apply local interactions forming a minimum energy structure. Currently, self-assembled materials are considered for biomedical applications due to their pleasant features, including scalability, versatility, simplicity, and inexpensiveness. Self-assembled peptides can be applied to design and fabricate different structures, such as micelles, hydrogels, and vesicles, by diverse physical interactions between specific building blocks. Among them, bioactivity, biocompatibility, and biodegradability of peptide hydrogels have introduced them as versatile platforms in biomedical applications, such as drug delivery, tissue engineering, biosensing, and treating different diseases. Moreover, peptides are capable of mimicking the microenvironment of natural tissues and responding to internal and external stimuli for triggered drug release. In the current review, the unique characteristics of peptide hydrogels and recent advances in their design, fabrication, as well as chemical, physical, and biological properties are presented. Additionally, recent developments of these biomaterials are discussed with a particular focus on their biomedical applications in targeted drug delivery and gene delivery, stem cell therapy, cancer therapy and immune regulation, bioimaging, and regenerative medicine.

Correlates of sedentary behavior in Asian preschool-aged children: A systematic review.

This systematic review aims to identify the multilevel correlates of sedentary behavior (SB) and its sub-domains among preschool-aged children aged 0-7 years in Asia. We systematically searched for studies published from 2000 onwards using terms related to SB correlates and Asia in six databases. Eligible studies were observational and used quantitative methods to examine correlates of total, and domain-specific SB (screen viewing [SV] and non-screen-based SB) in Asian children living in Asia. Two reviewers independently screened identified references. Following quality assessment of included studies, we performed narrative synthesis to summarize the evidence on the intrapersonal, interpersonal, environmental correlates of total and domain-specific SB (PROSPERO: CRD42018095268). Twenty-two studies from 4 regions and 12 countries/territories were included. Out of the 94 correlates explored, the following associations were consistent: older age, being a boy, non-Chinese ethnicity (Southeast Asia), younger maternal age, higher maternal and paternal television-viewing time with higher SV; higher SV at earlier age with higher SV and total SB; and presence of TV/computer in the bedroom with higher leisure-time SB. We encourage more studies from low- and middle-income Asian countries with an increased focus on different SB domains, further exploration of environmental correlates, and the use of objective measurements to capture SB.

Global Matrix 4.0 Physical Activity Report Card Grades for Children and Adolescents: Results and Analyses From 57 Countries.

BACKGROUND: The Global Matrix 4.0 on physical activity (PA) for children and adolescents was developed to achieve a comprehensive understanding of the global variation in children's and adolescents' (5-17 y) PA, related measures, and key sources of influence. The objectives of this article were (1) to summarize the findings from the Global Matrix 4.0 Report Cards, (2) to compare indicators across countries, and (3) to explore trends related to the Human Development Index and geo-cultural regions. METHODS: A total of 57 Report Card teams followed a harmonized process to grade the 10 common PA indicators. An online survey was conducted to collect Report Card Leaders' top 3 priorities for each PA indicator and their opinions on how the COVID-19 pandemic impacted child and adolescent PA indicators in their country. RESULTS: Overall Physical Activity was the indicator with the lowest global average grade (D), while School and Community and Environment were the indicators with the highest global average grade (C+). An overview of the global situation in terms of surveillance and prevalence is provided for all 10 common PA indicators, followed by priorities and examples to support the development of strategies and policies internationally. CONCLUSIONS: The Global Matrix 4.0 represents the largest compilation of children's and adolescents' PA indicators to date. While variation in data sources informing the grades across countries was observed, this initiative highlighted low PA levels in children and adolescents globally. Measures to contain the COVID-19 pandemic, local/international conflicts, climate change, and economic change threaten to worsen this situation.

Identification of microRNAs expressed highly in pancreatic islet-like cell clusters differentiated from human embryonic stem cells.

Type 1 diabetes is an autoimmune destruction of pancreatic islet beta cell disease, making it important to find a new alternative source of the islet beta cells to replace the damaged cells. hES (human embryonic stem) cells possess unlimited self-renewal and pluripotency and thus have the potential to provide an unlimited supply of different cell types for tissue replacement. The hES-T3 cells with normal female karyotype were first differentiated into EBs (embryoid bodies) and then induced to generate the T3pi (pancreatic islet-like cell clusters derived from T3 cells), which expressed pancreatic islet cell-specific markers of insulin, glucagon and somatostatin. The expression profiles of microRNAs and mRNAs from the T3pi were analysed and compared with those of undifferentiated hES-T3 cells and differentiated EBs. MicroRNAs negatively regulate the expression of protein-coding mRNAs. The T3pi showed very high expression of microRNAs, miR-186, miR-199a and miR-339, which down-regulated the expression of LIN28, PRDM1, CALB1, GCNT2, RBM47, PLEKHH1, RBPMS2 and PAK6. Therefore, these microRNAs and their target genes are very likely to play important regulatory roles in the development of pancreas and/or differentiation of islet cells, and they may be manipulated to increase the proportion of beta cells and insulin synthesis in the differentiated T3pi for cell therapy of type I diabetics.

Effective immobilization of Bacillus subtilis in chitosan-sodium alginate composite carrier for ammonia removal from anaerobically digested swine wastewater.

To overcome the easy loss of microorganism, the mass production of sludge and the consumption of aeration energy during biological treatment of anaerobically digested swine wastewater, this study used chitosan-sodium alginate composite carrier to prepare immobilized bacteria pellets. The heterotrophic bacteria tolerant to high concentrations of ammonia nitrogen were isolated and the conditions for immobilizing bacteria were optimized. The performance of immobilized bacteria pellets to remove ammonia nitrogen from ADSW was determined and the corresponding mechanism was investigated. Results showed that the isolated bacteria were Bacillus subtilis, and the optimal conditions to prepare the immobilized bacteria pellets by response surface methodology tests were sodium alginate of 0.84% (m/V), chitosan of 0.22% (m/V), embedding time of 32 min and embedding amount of 15% (V/V). In ADSW treatment, at pH 6, 20 g/L of the immobilized bacteria pellets removed 96.5% of ammonia nitrogen. Both adsorption and microbial action contributed to ammonia nitrogen removal, and their contributions were 54.3% and 42.2%, respectively. Compared with the immobilized bacteria pellets using chitosan-sodium alginate as carrier, the one using mono alginate as carrier had a weaker ability to remove ammonia nitrogen, with a removal efficiency of 67.4%. The main mechanism was the formation of polyelectrolyte membrane by the connection between amino groups of chitosan and carboxyl groups of sodium alginate, which stabilized the immobilized bacteria pellets and prolonged their service life. To sum up, the immobilized bacteria pellets using chitosan-sodium alginate as an embedding agent have a promising prospect in ammonia nitrogen removal from wastewater.

Identification of microRNAs regulated by activin A in human embryonic stem cells.

Human embryonic stem (hES) cells have the capacities to propagate for extended periods and to differentiate into cell types from all three germ layers both in vitro and in vivo. These characteristics of self-renewal and pluripotency enable hES cells having the potential to provide an unlimited supply of different cell types for tissue replacement, drug screening, and functional genomics studies. The hES-T3 cells with normal female karyotype cultured on either mouse embryonic fibroblasts (MEF) in hES medium (containing 4 ng/ml bFGF) (T3MF) or feeder-free Matrigel in MEF-conditioned medium (supplemented with additional 4 ng/ml bFGF) (T3CM) were found to express very similar profiles of mRNAs and microRNAs, indicating that the unlimited self-renewal and pluripotency of hES cells can be maintained by continuing culture on these two conditions. However, the expression profiles, especially microRNAs, of the hES-T3 cells cultured on Matrigel in hES medium supplemented with 4 ng/ml bFGF and 5 ng/ml activin A (T3BA) were found to be different from those of T3MF and T3CM cells. In T3BA cells, four hES cell-specific microRNAs miR-372, miR-302d, miR-367, and miR-200c, as well as three other microRNAs miR-199a, miR-19a, and miR-217, were found to be up-regulated, whereas five miRNAs miR-19b, miR-221, miR-222, let-7b, and let-7c were down-regulated by activin A. Thirteen abundantly differentially expressed mRNAs, including NR4A2, ERBB4, CXCR4, PCDH9, TMEFF2, CD24, and COX6A1 genes, targeted by seven over-expressed miRNAs were identified by inverse expression levels of these seven microRNAs to their target mRNAs in T3BA and T3CM cells. The NR4A2, ERBB4, and CXCR4 target genes were further found to be regulated by EGF and/or TNF. The 50 abundantly differentially expressed genes targeted by five under-expressed miRNAs were also identified. The abundantly expressed mRNAs in T3BA and T3CM cells were also analyzed for the network and signaling pathways, and roles of activin A in cell proliferation and differentiation were found. These findings will help elucidate the complex signaling network which maintains the self-renewal and pluripotency of hES cells.

Understanding physical activity and sedentary behaviour among preschool-aged children in Singapore: a mixed-methods approach.

OBJECTIVES: This study investigated physical activity (PA) and sedentary behaviour (SB) among preschool-aged children in Singapore and potential correlates at multiple levels of the socioecological model from in-school and out-of-school settings. DESIGN: A cross-sectional study using a mixed-methods approach. PARTICIPANTS: Parent-child dyads from six preschools in Singapore. METHODS: PA and SB of children (n=72) were quantified using wrist-worn accelerometers for seven consecutive days. Three focus group discussions (FGDs) among 12 teachers explored diverse influences on children's activities, and System for Observing Play and Leisure Activity in Youth (SOPLAY) assessed PA environment and children's activity levels at preschools. Seventy-three parents completed questionnaires on home and neighbourhood factors influencing children's PA and SB. Descriptive analyses of quantitative data and thematic analysis of FGDs were performed. RESULTS: Based on accelerometry, children (4.4±1.1 years) spent a median of 7.8 (IQR 6.4-9.0) hours/day in SB, and 0.5 (0.3-0.8) hours/day in moderate-to-vigorous physical activity (MVPA). MVPA was similar throughout the week, and SB was slightly higher on non-school days. In preschools, SOPLAY showed more children engaging in MVPA outdoors (34.0%) than indoors (7.7%), and absence of portable active play equipment. FGDs revealed issues that could restrict active time at preschool, including academic requirements of the central curriculum and its local implementation. The teachers had varying knowledge about PA guidelines and perceived that the children were sufficiently active. In out-of-school settings, parents reported that their children rarely used outdoor facilities for active play and spent little time in active travel. Few children (23.5%) participated in extracurricular sports, but most (94.5%) reported watching screens for 1.5 (0.5-3.0) hours/day. CONCLUSION: MVPA was low and SB was high in preschool-aged children in an urban Asian setting. We identified diverse in-school and out-of-school correlates of PA and SB that should be taken into account in health promotion strategies.

Correlates of sedentary behaviour in Asian adults: A systematic review.

The objective of this study is to systematically review the evidence on correlates of sedentary behaviour (SB) among Asian adults. We searched for studies that examined individual, environmental, and political/cultural correlates of total and domain-specific SB (transport, occupation, leisure, and screen time) in Asian adults published from 2000 onwards in nine scientific databases. Two reviewers independently screened identified references. Following quality assessment of included studies, we performed narrative synthesis that considered differences based on SB measurements, regions, and population characteristics (PROSPERO: CRD42018095268). We identified 13 249 papers of which we included 49, from four regions and 12 countries. Researchers conducted cross-sectional analyses and most relied on SB self-report for SB measurement. Of the 118 correlates studied, the following associations were consistent: higher age, living in an urban area (East Asia), and lower mental health with higher total SB; higher education with higher total and occupational SB; higher income with higher leisure-time SB; higher transit density with higher total SB in older East Asians; and being an unmarried women with higher SB in the Middle East. We encourage more research in non-high-income countries across regions, further exploration of important but neglected correlates using longitudinal designs and qualitative research, and the use of objective instruments to collect SB data.

Associations between early-life screen viewing and 24 hour movement behaviours: findings from a longitudinal birth cohort study.

BACKGROUND: Screen viewing is a sedentary behaviour reported to interfere with sleep and physical activity. However, few longitudinal studies have assessed such associations in children of preschool age (0-6 years) and none have accounted for the compositional nature of these behaviours. We aimed to investigate the associations between total and device-specific screen viewing time at age 2-3 years and accelerometer-measured 24 h movement behaviours, including sleep, sedentary behaviour, light physical activity, and moderate-to-vigorous physical activity (MVPA) at age 5·5 years. METHODS: The Growing Up in Singapore Towards healthy Outcomes (GUSTO) study is an ongoing longitudinal birth cohort study in Singapore, which began in June 2009. We recruited pregnant women during their first ultrasound scan visit at two major public maternity units in Singapore. At clinic visits done at age 2-3 years, we collected parent-reported information about children's daily total and device-specific screen viewing time (television, handheld devices, and computers). At 5·5 years, children's movement behaviours for 7 consecutive days were measured using wrist-worn accelerometers. We assessed the associations between screen viewing time and movement behaviours (sedentary behaviour, light physical activity, MVPA, and sleep) using Dirichlet regression, which accounts for the compositional nature of such behaviours. This study is active but not recruiting and is registered with ClinicalTrials.gov, NCT01174875. FINDINGS: Between June 1, 2009, and Oct 12, 2010, 1247 pregnant women enrolled and 1171 singleton births were enrolled. 987 children had parent-reported screen data at either 2 or 3 years, of whom 840 attended the clinic visit at age 5·5 years, and 577 wore an accelerometer. 552 children had at least 3 days of accelerometer data and were included in the analysis. Total screen viewing time at age 2-3 years had a significant negative association with sleep (p=0·008), light physical activity (p<0·0001), and MVPA (p<0·0001) in relation to sedentary behaviour at age 5·5 years. Compared with children who spent 1 h or less per day screen viewing at age 2-3 years, children who screen viewed for 3 h or more per day at 2-3 years engaged in more sedentary behaviour (439·8 mins per day [≤1 h screen viewing time] vs 480·0 mins per day [≥3 h screen viewing time]), and less light physical activity (384·6 vs 356·2 mins per day), and MVPA (76·2 vs 63·4 mins per day) at age 5·5 years. No significant differences in time spent sleeping were observed between the groups (539·5 vs 540·4 mins per day). Similar trends were observed for television viewing and handheld device viewing. INTERPRETATION: Longer screen viewing time in children aged 2-3 years was associated with more time spent engaged in sedentary behaviour and shorter time engaged in light physical activity and MVPA in later childhood. Our findings indicate that screen viewing might displace physical activity during early childhood, and suggest that reducing screen viewing time in early childhood might promote healthier behaviours and associated outcomes later in life. FUNDING: Singapore National Research Foundation, and Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR).