An Atlas of Grass Carp IgM+ B Cells in Homeostasis and Bacterial Infection Helps to Reveal the Unique Heterogeneity of B Cells in Early Vertebrates.

Teleost B cells are primitive lymphocytes with both innate and adaptive immune functions. However, the heterogeneity and differentiation trajectory of teleost B cells remain largely unknown. In this study, the landscape of grass carp IgM+ (gcIgM+) B cells was revealed by single-cell RNA sequencing. The results showed that gcIgM+ B cells mainly comprise six populations: (im)mature B cells, innate B cells, proliferating B cells, plasma cells, CD22+ cells, and CD34+ cells, among which innate B cells and proliferating B cells were uncommon B cell subsets with, to our knowledge, new characteristics. Remarkably, three functional IgMs were discovered in grass carp, and a significant percentage of gcIgM+ B cells, especially plasma cells, expressed multiple Igµ genes (Igµ1, Igµ2, and/or Igµ3). More importantly, through single-cell sorting combined with Sanger sequencing, we found that distinct VHDJH recombination patterns of Igµ genes were present in single IgM+ B cells, indicating that individual teleost B cells might produce multiple Abs by coexpressing rearranged IgM subclass genes. Moreover, the percentage of IgM1highIgM2highIgM3high plasma cells increased significantly after bacterial infection, suggesting that individual plasma cells might tend to produce multiple IgMs to resist the infection in teleost fish. In summary, to our knowledge, this study not only helps to uncover the unique heterogeneity of B cells in early vertebrates but also provided significant new evidence supporting the recently proposed "one cell-multiple Abs" paradigm, challenging the classical rule of "one cell-one Ab."

Identification and functional analyses of CD4-1+ cells in grass carp (Ctenopharyngodon idella).

In mammals, CD4 is found to be expressed on T cells and innate immune cells, however, teleost cells bearing CD4 have not been well identified and characterized. In this study, we identified two different CD4-1+ cell subsets in grass carp (Ctenopharyngodon idella): CD4-1+ lymphocytes (Lym) and CD4-1+ myeloid cells (Mye), both of which had the highest proportions in the head kidney. The mRNA expression analysis showed that CD4-1, CD4-2, TCRß, CD3γ/δ, and LCK1 are highly expressed in CD4-1+ Lym and also expressed in CD4-1+ Mye. Furthermore, we found that CD4-1+ Lym have a Lym morphology and highly express T-cell cytokines, suggesting that they are CD4+ T cells equivalent to mammalian Th cells. On the other hand, CD4-1+ Mye were found to have a morphology of macrophage and highly express macrophage marker gene MCSFR, indicating that they are macrophages. In addition, functional analysis revealed that CD4-1+ Mye possess phagocytic ability and great antigen-processing ability. Taken together, our study sheds further light on the composition and function of CD4+ cells in teleost fish.

Insights into the Antibacterial Properties of Complement Peptides C3a, C4a, and C5a across Vertebrates.

Complement peptides C3a, C4a, and C5a are important components of innate immunity in vertebrates. Although they diverged from a common ancestor, only C3a and C4a can act as antibacterial peptides in Homo sapiens, suggesting that C5a has evolved into a purely chemotactic molecule; however, the antibacterial properties of C3a, C4a, and C5a across vertebrates still require elucidation. In this article, we show that, unlike those in H. sapiens, Mus musculus C3a, C4a, and C5a all possess antibacterial activities, implying that the antibacterial properties of C3a, C4a, and C5a have evolved divergently in vertebrates. The extremely different net charge, a key factor determining the antibacterial activities of cationic antimicrobial peptides, of vertebrate C3a, C4a, and C5a supports this speculation. Moreover, the antibacterial activity of overlapping peptides covering vertebrate C3a, C4a, and C5a further strongly supports the speculation, because their activity is positively correlated with the net charge of source molecules. Notably, the structures of C3a, C4a, and C5a are conserved in vertebrates, and the inactive overlapping peptides can become antibacterial peptides if mutated to possess enough net positive charges, indicating that net charge is the only factor determining the antibacterial properties of vertebrate C3a, C4a, and C5a. More importantly, many vertebrate C3a-, C4a-, and C5a-derived peptides possess high antibacterial activities yet exhibit no hemolytic activities, suggesting the application potential in anti-infective therapy. Taken together, our findings reveal that vertebrate C3a, C4a, and C5a are all sources of antibacterial peptides that will facilitate the design of excellent peptide antibiotics.

Insights into the Antibacterial Properties of Complement Peptides C3a, C4a, and C5a across Vertebrates.

Complement peptides C3a, C4a, and C5a are important components of innate immunity in vertebrates. Although they diverged from a common ancestor, only C3a and C4a can act as antibacterial peptides in Homo sapiens, suggesting that C5a has evolved into a purely chemotactic molecule; however, the antibacterial properties of C3a, C4a, and C5a across vertebrates still require elucidation. In this article, we show that, unlike those in H. sapiens, Mus musculus C3a, C4a, and C5a all possess antibacterial activities, implying that the antibacterial properties of C3a, C4a, and C5a have evolved divergently in vertebrates. The extremely different net charge, a key factor determining the antibacterial activities of cationic antimicrobial peptides, of vertebrate C3a, C4a, and C5a supports this speculation. Moreover, the antibacterial activity of overlapping peptides covering vertebrate C3a, C4a, and C5a further strongly supports the speculation, because their activity is positively correlated with the net charge of source molecules. Notably, the structures of C3a, C4a, and C5a are conserved in vertebrates, and the inactive overlapping peptides can become antibacterial peptides if mutated to possess enough net positive charges, indicating that net charge is the only factor determining the antibacterial properties of vertebrate C3a, C4a, and C5a. More importantly, many vertebrate C3a-, C4a-, and C5a-derived peptides possess high antibacterial activities yet exhibit no hemolytic activities, suggesting the application potential in anti-infective therapy. Taken together, our findings reveal that vertebrate C3a, C4a, and C5a are all sources of antibacterial peptides that will facilitate the design of excellent peptide antibiotics.

Factors influencing senior care and living preferences among older adults in Jiangsu, China: a cross-sectional survey study.

BACKGROUND: As the population ages, senior care for older adults in China has become increasingly important and has attracted the attention of both government and society. This study aimed to explore preferences and influencing factors related to senior care among older Chinese adults and thus propose effective and targeted strategies for the development of a comprehensive care system for older adults in the aging Chinese population. METHODS: Data were obtained from a cross-sectional survey conducted in sixteen communities or villages in Jiangsu Province, China, from July to September 2021. Guided by the Andersen Behavioral Model, multivariate logistic regression was conducted to identify factors associated with preferences for senior care arrangements. RESULTS: A total of 870 respondents were included in the study, 60.11% of whom preferred receiving care in their own homes, while only 13.68% chose residential care facilities (RCFs). For predisposing factors, rural respondents preferred receiving care in their own homes compared to urban respondents (children's home: OR = 0.55, P < 0.01; RCF: OR = 0.58, P < 0.01). Concerning enabling factors, respondents who were not employed (OR = 2.30, P < 0.01) and those without financial support (OR = 2.73, P < 0.05) preferred RCFs to their own homes. Respondents receiving life assistance (sometimes: OR = 2.76, P < 0.001; regularly: OR = 2.57, P < 0.01; every day: OR = 3.57, P < 0.001) preferred their children's homes to their own homes. In terms of need factors, respondents with noncommunicable diseases (NCDs, OR > 1, P < 0.05), those who knew about RCFs (some: OR = 0.53, P < 0.005; no: OR = 0.10, P < 0.001) and those with a good impression of RCFs (fair: OR = 3.72, P < 0.05; good: OR = 11.91, P < 0.001) preferred receiving care in RCFs compared to their counterparts. CONCLUSIONS: Older Chinese adults' senior care preferences were affected by predisposing factors, enabling factors, and need factors. Policy-makers should consider targeted measures to identify more precise senior care services and thus address aging challenges in China.

Old people's preference for nursing homes in East China: a discrete choice experiment.

BACKGROUND: The aged people who live in nursing home are predicted to keep growing in the following decades. There are both quantitative imbalance and structural imbalance in the utilization of nursing homes in China. This study aimed to analyze old people's preference for nursing homes and help the government optimize resource allocation. METHODS: A discrete choice experiment (DCE) was conducted and six attributes of nursing homes including monthly fee, distance from home, geographical location, medical facilities, environment of nursing homes and nursing staff were determined. Respondents were recruited from Nantong and Yangzhou city, China. In each city, two communities or villages were randomly selected. In each community/village, about 65 old people were randomly selected. Analysis was conducted using mixed logit regression models to determine preferences for potential attributes. RESULTS: A total of 233 old people were included in the analysis. The findings indicated that all six attributes were statistically significant factors for participants. "Professional nursing staff" was the most important characteristic to participants, followed by "Medical facilities". Compared with female, the males preferred professional nursing staff (ß = 2.939 vs. ß = 2.643, P < 0.001), medical facilities (ß = 1.890 vs. ß = 1.498, P < 0.001), and the environment (ß = 0.752, P < 0.01). For different age groups, participants aged 60-69 didn't pay attention to distance and location, while those aged 80 and above only paid attention to professional nursing staff and medical facilities. CONCLUSIONS: The present study provides important insights into the characteristics of nursing home that are most preferred by old people. Authorities should take into account old people's preference in the planning, design and evaluation of nursing homes.

Identification of signalling downstream of the transcription factor forkhead box protein M1 that protects against endoplasmic reticulum stress in a diabetic foot ulcer model.

AIMS: Diabetic foot ulcer (DFU) has a significant impact on the quality of life of diabetic mellitus (DM) patients. Here, we aimed to explore the molecules with aberrant expression and their regulatory mechanisms in DFU. METHODS: The expression of gene and protein was examined using quantitative polymerase chain reaction (qPCR) and western blot. Pearson's correlation analysis was used to analyse interactions among FOXM1, GAS5 and SDF4. Immunofluorescence was used to detect PDI and GRP78 expression. Flow cytometry was used to assess cell apoptosis. Tube formation assay was used to determine angiogenic capacity. Fluorescence in situ hybridization (FISH) assay was employed to determine the cellular localization of GAS5 and SDF4 in human umbilical vein endothelial cells (HUVECs). The interactions among FOXM1, GAS5 and SDF4 were validated by chromatin immunoprecipitation (ChIP), luciferase, RNA pull-down and RNA immunoprecipitation (RIP) assays. RESULTS: FOXM1, GAS5 and SDF4 were decreased in the skin tissues of DFU patients. High glucose (HG) stimulation induced endoplasmic reticulum (ER) stress and cell apoptosis but suppressed angiogenesis in HUVECs, which were abolished by FOXM1 overexpression. FOXM1 promoted GAS5 transcriptional activity, resulting in increased GAS5 expression, and GAS5 knockdown reversed the effects of FOXM1 overexpression in HG-treated HUVECs. Moreover, GAS5 recruited TAF15 to promote SDF4 expression in HUVECs. GAS5 overexpression inhibited ER stress, cell apoptosis and induced angiogenesis in HG-treated HUVECs which could be reversed by silencing SDF4. CONCLUSION: Our results revealed that FOXM1 suppressed ER stress, cell apoptosis and promoted angiogenesis in HG-induced HUVECs via mediating GAS5/TAF15/SDF4 axis, providing a novel therapeutic molecule mechanism for DFU.

A serial mediation model of social media addiction and college students' academic engagement: the role of sleep quality and fatigue.

BACKGROUND: It has been documented that social media addiction (SMA) has a detrimental effect on college students' academic engagement. However, the mechanisms underlying this association are not well understood. This study aimed to determine the serial mediation effects of sleep quality and fatigue on the relationship between SMA and academic engagement among college students. METHODS: A cross-sectional survey was conducted with 2661 college students (43.3% males, mean age = 19.97 years). The participants completed the Bergen Social Media Addiction Scale, the Utrecht Student Work Engagement Scale for Students, the Pittsburgh Sleep Quality Index, and the Fatigue Assessment Scale. The serial mediation effects were examined using Model 6 in the Hayes' PROCESS macro for SPSS. RESULTS: The results showed that SMA among college students had a direct negative relationship with their academic engagement (Effect = - 0.051, 95% CI: -0.087 to - 0.015). In addition, sleep quality and fatigue mediated the relationship between SMA and academic engagement both independent and serially, with the independent mediation effect of sleep quality being - 0.031 (95% CI: -0.048 to - 0.016), the independent mediation effect of fatigue being - 0.109 (95% CI: -0.133 to - 0.088), and the serial mediation effect of sleep quality and fatigue being - 0.080 (95% CI: -0.095 to - 0.066). The total indirect effect of the three mediation paths was 80.9%. CONCLUSIONS: Decreased academic engagement caused by SMA can be aggravated by poor sleep quality and fatigue. Strengthening supervision and intervention in social media use among college students, supplemented by attention to psychosomatic health, including sleep quality and fatigue could promote their engagement in academic work.

Prevalence, patterns of multimorbidity and associations with health care utilization among middle-aged and older people in China.

BACKGROUND: Multimorbidity has become one of the main challenges in health care system. The association between prevalence, patterns of multimorbidity and health care utilization is less often discussed in China. The purpose of this study is to examine this association among Chinese middle-aged and older adults and take into account different sociodemographic, behavioral and health characteristics. Based on this, implications of current evidence and effective intervention on multimorbidity and health care utilization can be identified and put into practice. METHODS: The wave 4 in 2018 of the China Health and Retirement Longitudinal Study (CHARLS) was used in the study. Multimorbidity was defined as the co-occurrence of two or more chronic medical condition of a list of fourteen chronic diseases in one person. The presence of chronic diseases was assessed through self-report. Health care utilization include whether the respondents received outpatient service last month and inpatient service in the past year. Latent Class Analysis was conducted to identify the clustering pattern of chronic diseases. Logistic regressions were employed to explore the association between prevalence, patterns of multimorbidity and health care utilization. Analyses were weighted using individual sample weights, adjusted for non-response of individual and household. RESULTS: Among 19,559 participants aged 45 and older, 23.10% were aged above 70 years and 52.42% were female. The prevalence of multimorbidity was 56.73%. Four patterns were identified: relatively healthy class, respiratory class, stomach-arthritis class and vascular class. Multimorbid individuals used more outpatient services (OR = 1.89, 95%CI = 1.65-2.17) and more inpatient services (OR = 2.52, 95%CI = 2.22-2.86) compared to their no-multimorbid counterparts. Compared to relatively healthy class, the respondents classified into respiratory class, stomach-arthritis class and vascular class used more outpatient services (OR = 1.90, 95%CI = 1.57-2.30; OR = 2.39, 95%CI = 2.06-2.78; OR = 1.53, 95%CI = 1.32-1.79 respectively) and more inpatient services (OR = 2.19, 95%CI = 1.83-2.62; OR = 2.93, 95%CI = 2.53-3.40; OR = 1.90, 95%CI = 1.65-2.19 respectively). CONCLUSION: Our study provided evidence that multimorbidity is high among Chinese older adults and is associated substantially higher health care utilization in China. Four multimorbidity patters were identified. Policy should prioritize improving the management of individuals with multimorbidity to increase healthcare efficiency. Further research is necessary with special emphasis on the trajectory of multimorbidity and the role of health system in satisfying needs of multimorbid individuals.

LncRNA GAS5 activates the HIF1A/VEGF pathway by binding to TAF15 to promote wound healing in diabetic foot ulcers.

A diabetic foot ulcer (DFU) is one of the most devastating complications of diabetes. It has been reported that lncRNA GAS5 plays a vital role in wound healing in DFUs. However, the specific mechanism remains unclear. In this research, we aimed to investigate the role of GAS5 in wound healing in DFUs as well as the underlying mechanism. qPCR or western blotting was performed to measure the expression levels of GAS5, HIF1A, VEGF and TAF15. CCK-8 or EdU assays, flow cytometry, wound healing assays and tube formation assays were carried out to assess the proliferation, apoptosis, wound healing and in vitro angiogenesis of HUVECs, respectively. RNA pull-down and RIP assays were performed to verify the interaction between GAS5 and TAF15. ChIP and luciferase assays were conducted to verify the binding of TAF15 to the HIF1A promoter. In the DFU mouse model, H&E and Masson staining were used to determine epidermal and dermal thickness and collagen formation. GAS5 and HIF1A were downregulated in the skin tissues of DFU patients, and GAS5 overexpression promoted cell proliferation, wound healing and tubule formation in HG-treated HUVECs. In addition, GAS5 facilitated HIF1A expression by interacting with TAF15. Rescue assays demonstrated that the suppression of HIF1A/VEGF pathway activation partially reversed the functional roles of GAS5 in HUVECs. Furthermore, GAS5 accelerated wound healing by activating the HIF1A/VEGF pathway in mice with DFUs. GAS5 activates the HIF1A/VEGF pathway by binding to TAF15, resulting in accelerated wound healing in DFUs. Our findings may provide a theoretical basis for the clinical treatment of DFUs.

Social support and depressive symptoms among family caregivers of older people with disabilities in four provinces of urban China: the mediating role of caregiver burden.

BACKGROUND: To examine the relationship between social support and depressive symptoms of Chinese family caregivers of older people with disabilities, and to evaluate the role of caregiver burden as a potential mediator of that relationship. METHODS: A survey questionnaire was completed face-to-face by 567 primary family caregivers of older people with disabilities in four provinces in China. Covariates that may affect depressive symptoms, such as the characteristics of disabled people (socio-economic factors, functional and cognitive capacity) and caregivers (caregiver duration and self-rated health of caregivers) were collected. Social support was measured by the Multidimensional Scale of Perceived Social Support (MSPSS); depressive symptoms were assessed by the shortened 10 item version of Center for Epidemiological Studies Depression scale (CES-D); and the caregiver burden was assessed by the Zarit Burden Interview (ZBI). RESULTS: The prevalence of depressive symptoms among caregivers was 37.7%. Higher levels of social support was negatively associated with lower depressive symptoms. This relationship was partially mediated by the caregiver burden, where higher levels of the caregiver burden were negatively associated with depressive symptoms. Furthermore, caregivers who were women, spent extended time in caregiving and were in poor health, reported significantly higher depressive symptoms. CONCLUSIONS: Our results indicated that social support was negatively associated with depressive symptoms in family caregivers and in the caregiver burden. The caregiver burden partially mediated the social support-depressive symptoms association. Interventions for family caregivers should include increasing social support, health monitoring and structured interventions to reduce the caregiver burden and attenuate family caregivers' depressive symptoms.

Gender, childhood and adult socioeconomic inequalities in functional disability among Chinese older adults.

BACKGROUND: Gender difference and life-course socioeconomic inequalities in functional disability may exist among older adults. However, the association is less well understood among Chinese older population. The objective is to provide empirical evidences on this issue by exploring the association between gender, childhood and adult socioeconomic inequalities in functional disability. METHODS: Data from the 2013 wave of the China Health and Retirement Longitudinal Study (CHARLS) was utilized. Functional disability was assessed by the activities of daily living (ADL) and instrumental activities of daily living (IADL). Childhood socioeconomic status (SES) was measured by birthplace, father's education and occupation. Adult SES was measured in terms of education and household income. Multivariate logistic regressions were conducted to assess the association between gender, childhood and adult SES and functional disability. RESULTS: Based on a sample of 18,448 older adults aged 45 years old and above, our results showed that the prevalence of ADL and IADL disability was higher among women than men, but gender difference disappeared after adult SES and adult health were controlled. Harsh conditions during childhood were associated with functional disability but in multivariate analyses only father's education was associated with IADL disability (OR for no education = 1.198; 95% CI = 1.062-1.353). Current SES such as higher education and good economic situation are protective factors of functional disability. CONCLUSIONS: Childhood and adult SES were both related to functional disability among older adults. Our findings highlight the need for policies and programs aimed at decreasing social inequalities during childhood and early adulthood, which could reduce socioeconomic inequalities in functional disability in later life.

Association between social capital and health-related quality of life among left behind and not left behind older people in rural China.

BACKGROUND: The association between social capital and health-related quality of life (HRQoL) has not been thoroughly studied among older persons in rural China, especially among those who were left behind or not. This study investigates the association between social capital and HRQoL and examines possible differences of this association between being left behind or not in rural China. METHODS: A cross-sectional survey of 825 people aged 60 years and older, residing in three rural counties in Jiangsu Province in China, was conducted in 2013. Factor analysis was performed to measure social capital. EQ-5D was used to measure HRQoL. Tobit regression analysis with upper censoring was conducted to explore the association between social capital and EQ-5D index. RESULTS: After controlling for individual characteristics, low social capital and being left behind were significantly associated with low HRQoL. Old people with low social capital had 0.055 lower EQ-5D index compared to those with high social capital. Old people being left behind had 0.040 lower EQ-5D index compared to those who were not left behind. For different dimensions of social capital, the main effects came from the domain of trust and reciprocity. There was a significant interaction between low social capital and being left behind on HRQoL, suggesting that low social capital was associated with low HRQoL among persons left behind. CONCLUSIONS: Our findings indicate that the left behind old people with low social capital were a potentially vulnerable group in rural China. Formulating and implementing initiatives and strategies which increase social capital may foster better HRQoL, especially for old people who were left behind.

Comparative transcriptome profiling of potassium starvation responsiveness in two contrasting watermelon genotypes.

Potassium (K) is one of the essential nutrients for crops, and K⁺ deficiency highly restricts crop yield and quality. Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is an economically important crop that often suffers from K⁺ deficiency. To elucidate the underlying tolerance mechanism of watermelon to K⁺ deficiency and to improve K efficiency of watermelon and other crops in the future, two watermelon genotypes, namely, YS and 8424, that exhibit contrasting K efficiencies were studied to compare their response mechanisms to K⁺ deficiency. YS was more tolerant of K⁺ deficiency and displayed less inhibited root growth than 8424. Roots of YS and 8424 seedlings with or without K⁺ supply were harvested at 6 and 120 h after treatment (HAT), and their transcriptomes were analyzed by Illumina RNA sequencing. Different regulation mechanisms of the root K⁺-uptake genes for short- and long-term stress were observed. Genes involved in jasmonic acid and reactive oxygen species production; Ca²âº and receptor-like kinase signaling; lignin biosynthesis; and other stress-related genes were repressed in YS, whereas a large number of such stress-related genes were induced in 8424 at 120 HAT. These results suggested that repressed defense and stress response can save energy for better root growth in YS, which can facilitate K⁺ uptake and increase K efficiency and tolerance to K⁺ deficiency. This study presents the first global root transcriptome in watermelon and provides new insights into the molecular mechanisms underlying tolerance to K⁺ deficiency of K-efficient watermelon genotypes.

The relationship between family functioning and social media addiction among university students: a moderated mediation model of depressive symptoms and peer support.

BACKGROUND: Social media addiction (SMA) is an increasing problem, especially among young adults. Little is known about university students' SMA and family functioning. This study aimed to explore the mediating effect of depressive symptoms and the moderating effect of peer support in the relationship between family functioning and SMA among young adults. METHODS: A sample of 1862 Chinese university students completed an online survey including the Bergen Social Media Addiction Scale (BSMAS), Family APGAR, the Patient Health Questionnaire (PHQ-9), peer support, and demographic characteristics. Hierarchical regression and moderated mediation analysis were used to test the effects and pathways among them. RESULTS: Of the 1840 participants, 30.11% experienced SMA, 38.80% had family dysfunction and 15.98% had depressive symptoms. Hierarchical multiple regression showed better family functioning significantly predicted less SMA (ß = -0.26, p < 0.001) and lower depressive symptoms (ß = -0.58, p < 0.001), after adjusting for covariates. Mediation analysis verified that depressive symptoms mediated the effect of family functioning on SMA (indirect effect = -0.22, 95%CI[-0.28, -0.17]). Furthermore, the interaction of family functioning and peer support was negatively related to depressive symptoms (ß= -0.03, 95% CI[-0.05, -0.01]) and the interaction of depressive symptoms and peer support was positively related to SMA (ß = 0.01, 95%CI[0.004, 0.02]). Additional analysis further confirmed that peer support decreased depressive symptoms among young adults from dysfunctional families, and increased SMA behaviors in individuals with depressive symptoms. CONCLUSION: Better family functioning and lower depressive symptoms may contribute to less social media addiction among Chinese university students. Peer support could moderate the mediating role of depressive symptoms on social media addiction in individuals with family dysfunction.

Social media addiction and academic engagement as serial mediators between social anxiety and academic performance among college students.

BACKGROUND: Social anxiety has been shown to affect college students' academic performance. However, the role of social media addiction and academic engagement in this association is unclear. METHODS: A total 2661 college students completed a self-report questionnaire including Liebowitz Social Anxiety Scale, the Bergen Social Media Addiction Scale, the Utrecht Student Work Engagement Scale for Students, and the grade point average. Hayes' PROCESS macro for SPSS was employed to test the serial mediation effect. RESULTS: Results indicated that social anxiety was negatively related to academic performance, only academic engagement played a single mediating role in the relationship between social anxiety and academic performance, meanwhile social media addiction and academic engagement acted as serial mediators between social anxiety on academic performance. CONCLUSIONS: Social media addiction and academic engagement can explain the potential mechanisms of the association between social anxiety and academic performance, which have implications for devising intervention strategies to enhance the mental health and academic outcomes of college students.

Self-Medication with Antibiotics Among Children in China: A Cross-Sectional Study of Parents' Knowledge, Attitudes, and Practices.

Background: Self-medication with antibiotics (SMA) among children is a common practice in low-income and middle-income countries, which has accelerated antibacterial abuse. Objective: This study aimed to estimate the prevalence and associated factors of SMA among children in China, including parents' knowledge, attitudes, and practices towards antibiotic use. Methods: A cross-sectional study based on a structured questionnaire survey of parents was conducted in Nantong between July and September 2020. A total of 1699 respondents participated. Information on participants' demographic and family characteristics, knowledge, attitudes, and practices towards antibiotics use was collected. Hierarchical binary logistic regression was used to examine the predictors of SMA among children. Results: Among 1699 participants, 23.31% practiced SMA to their children in the past year. Cough (59.6%) was the most common symptom leading to self-medication and penicillins (85.4%) were the most commonly used drugs. Hierarchical regression indicated that parents with higher level of antibiotic knowledge scores (OR=1.163, 95% CI: 1.067-1.268) and buying antibiotics without a prescription from pharmacy (OR=1.475, 95% CI: 1.097-1.983) were more likely to practice SMA to their children both in urban and in rural areas. Storing antibiotics at home resulted in an increased likelihood of self-medication in urban areas but not in rural areas. In addition, there was also a higher probability of non-prescribed antibiotics in children without chronic diseases (OR=1.959, 95% CI:1.072-3.578). Conclusion: The prevalence of SMA in children is high in China. Higher knowledge scores and practices of buying and storing non-prescribed antibiotics behaviors increased parents' antibiotic self-medication in their children. Practical and effective education intervention for children's rational use of antibiotics is urgently strengthened.

The relationship between social anxiety and academic engagement among Chinese college students: A serial mediation model.

BACKGROUND: Few studies have elucidated the mechanisms linking social anxiety and academic engagement. This study aimed to explore the link between social anxiety and academic engagement through a series of mediating effects of social media addiction and sleep quality among college students. METHODS: 2661 college students completed the Liebowitz Social Anxiety Scale, the Bergen Social Media Addiction Scale, the Pittsburgh Sleep Quality Index, and the Utrecht Work Engagement Scale for Student. The serial mediation analysis was conducted using Hayes' PROCESS macro (Model 6). RESULTS: Social anxiety had a significantly direct effect on academic engagement (c = -0.162, p < 0.001) and through three significantly indirect pathways: (1) through social media addiction (B = -0.019, 95% CI: -0.027 to -0.011), accounting for 11.7% of the total effect; (2) through poor sleep quality (B = -0.043, 95% CI: -0.052 to-0.034), accounting for 26.5% of the total effect; and (3) through the serial mediators involving in social media addiction and poor sleep quality (B = -0.007, 95% CI: -0.009 to -0.005), accounting for 4.3% of the total effect. The total mediating effect was 42.6%. LIMITATIONS: This cross-sectional study prevented us from establishing causality. CONCLUSIONS: This study highlights the serial mediating role of social media addiction and sleep quality, the behavior and lifestyle factors, in the relationship between social anxiety and academic engagement. Therefore, social media addiction and sleep quality interventions for college students with social anxiety have the potential to improve their academic engagement.

Gender and Socioeconomic Differences in the Prevalence and Patterns of Multimorbidity among Middle-Aged and Older Adults in China.

BACKGROUND: Multimorbidity has become a global public health concern. Knowledge about the prevalence and patterns of multimorbidity will provide essential information for public intervention and clinical management. This study aimed to examine gender and socioeconomic differences in the prevalence and patterns of multimorbidity among a nationally representative sample of middle-aged and older Chinese individuals. METHODS: Data were obtained from the 2018 wave of the China Health and Retirement Longitudinal Study. Latent class analysis was conducted to discriminate among the multimorbidity patterns. Multinomial logit analysis was performed to explore gender and socioeconomic factors associated with various multimorbidity patterns. RESULTS: A total of 19,559 respondents over 45 years old were included in the study. The findings showed that 56.73% of the respondents reported multimorbidity, with significantly higher proportions among women. Four patterns, namely "relatively healthy class", "respiratory class", "stomach-arthritis class" and "vascular class", were identified. The women were more likely to be in the stomach-arthritis class. Respondents with a higher SES, including higher education, urban residence, higher consumption, and medical insurance, had a higher probability of being in the vascular class. Conclusions: Significant gender and socioeconomic differences were observed in the prevalence and patterns of multimorbidity. The examination of gender and socioeconomic differences for multimorbidity patterns has great implications for clinical practice and health policy. The results may provide insights to aid in the management of multimorbidity patients and improve health resource allocation.