Synthesis of novel nanoflowers-like P, K co-doped graphitic carbon nitride for efficient H2O2 photoproduction.

Photocatalytic oxygen reduction is considered an economical and green way to produce H2O2. Graphitic carbon nitride is a common photocatalyst, but its activity is limited by the low specific surface area and the high recombination rate of photogenerated electron-hole pairs. Herein, nanoflowers-like phosphorus (P) and potassium (K) co-doped graphitic carbon nitride (PKCN) is synthesized by co-polymerization of ammonium dihydrogen phosphate and melamine in the mixed molten salt (KCl/LiCl) medium. Within 90 min, the synthesized PKCN-0.05 can produce 4.97 mmol L-1 of H2O2, which is 7.8 times higher than that of pure bulk g-C3N4. The enhanced photocatalytic performance of PKCN-0.05 is mainly attributed to the following: 1) KCl/LiCl molten salt induces melamine to form a three-dimensional flower-like morphology, which expands the specific surface area, exposes more active sites, and improves the light utilization efficiency; 2) high crystallinity of PKCN-0.05 and the K ions inserted between the interlayers are beneficial for accelerating electron transfer; 3) the formation of PN bonds and the existence of N vacancies promotes the separation of photoproduced carriers; 4) the negatively shifted conduction band of PKCN-0.05 favors oxygen reduction.

Efficient photocatalytic H2O2 production and photodegradation of RhB over K-doped g-C3N4/ZnO S-scheme heterojunction.

Designing efficient dual-functional catalysts for photocatalytic oxygen reduction to produce hydrogen peroxide (H2O2) and photodegradation of dye pollutants is challenging. In this work, we designed and fabricated an S-scheme heterojunction (g-C3N4/ZnO composite photocatalyst) via one-pot calcination of a mixture of ZIF-8 and melamine in the KCl/LiCl molten salt medium. The KCN/ZnO composite produced 4.72 mM of H2O2 within 90 min under illumination (with AM 1.5 filter), which is almost 1.3 and 7.8 times than that produced over KCN and ZnO, respectively. Simultaneously, the KCN/ZnO also showed excellent photodegradation performance for the dye pollutants (Rhodamine B, RhB), with a removal rate of 92 % within 2 h. The apparent degradation rate constant of RhB over KCN/ZnO was approximately 5-8 times that of KCN and ZnO. In the photocatalytic process, photo-generated holes and superoxide radicals are the main active species. Oxygen (O2) was mainly reduced to produce H2O2 via a two-electron (2e-) pathway with superoxide radicals as intermediates and the 2e- oxygen reduction reaction selectivity of KCN/ZnO was close to 69.82 %. Photo-generated holes are mainly responsible for the degradation of RhB. Compared with pure KCN and ZnO, the enhanced photocatalytic activity of the KCN/ZnO composite is mainly attributed to the following aspects: 1) larger specific surface area and pore volume is beneficial to expose more active sites; 2) stronger light harvesting ability and red-shifted absorption edge bestow the compound a stronger light utilization efficiency; 3) the construction of S-scheme heterostructure between KCN and ZnO improve the photogenerated electron-hole pairs separation ability and bestow photogenerated carriers a higher redox potential.

Low-Frequency Sound-Insulation Performance of Labyrinth-Type Helmholtz and Thin-Film Compound Acoustic Metamaterial.

This paper presents a type of acoustic metamaterial that combines a labyrinth channel with a Helmholtz cavity and a thin film. The labyrinth-opening design and thin-film combination contribute to the metamaterial's exceptional sound-insulation performance. After comprehensive research, it is observed that in the frequency range of 20-1200 Hz, this acoustic metamaterial exhibits multiple sound-insulation peaks, showing a high overall sound-insulation quality. Specifically, the first sound-insulation peak is 26.3 Hz, with a bandwidth of 13 Hz and giving a transmission loss of 56.5 dB, showing excellent low-frequency sound-insulation performance. To further understand the low-frequency sound-insulation mechanism, this paper uses the equivalent model method to conduct an acoustic-electrical analogy, construct an equivalent model of the acoustic metamaterial, and delve into the sound-insulation mechanism at the first sound-insulation peak. To confirm the validity of the theoretical calculations, physical experiments are carried out by 3D printing experimental samples. The analysis of the experimental data has yielded results that are consistent with the simulation data, providing empirical evidence for the accuracy of the theoretical model. The material has significant practical application value. Finally, various factors are studied in depth based on the established equivalent model, which can provide valuable insights for the design and practical engineering application of acoustic metamaterials.

Exploring emission spatiotemporal pattern and potential reduction capacity in China's aviation sector: Flight trajectory optimization perspective.

China's rapid expansion of civil aviation has led to an increase in pollution-related issues, causing adverse health effects on populations near airports and downwind. Accurately quantifying aviation emissions is essential for effective emission management. Here, we developed a high-resolution aviation emissions inventory for China by employing a bottom-up approach that relied on daily flight schedules. By using the Aeronautical Information Publication (AIP) to reproduce real-world flight routes rather than conventional great-circle routes, we improved the accuracy of emissions and investigated the potential for reducing these emissions. Our findings demonstrated substantial variations in domestic civil aviation emissions both spatially and temporally. Emissions peaked in most provinces during Chinese holidays, particularly the Chinese Lunar New Year and summer holidays, highlighting the importance of detailed activity data for accurate emissions calculations. Therefore, we recommend extensive utilization of real-world flight routes, particularly in areas with limited Automatic Dependent Surveillance-Broadcast (ADS-B) coverage since they provide more accurate representations of actual flight trajectories. Our study also identified regions like Shaanxi, Sichuan, Beijing, and their surroundings having considerable potential for emission reduction due to substantial deviations from great-circle routes. This approach can enhance the accuracy and spatiotemporal resolution of aviation emissions at national and global scales throughout the year, without relying on extensive, long-term real-time flight trajectories. Additionally, it provides a unique way to quantify the potential for emission reductions across provinces in civil aviation, ultimately contributing to mitigating pollution-related health impacts from aviation emissions and promoting a more sustainable aviation industry.

Pollution Characteristics of Heavy Metals in PM1 and Source-Specific Health Risks in the Tianjin Airport Community, China.

The airport and its surrounding areas are home to a variety of pollution sources, and air pollution is a recognized health concern for local populated regions. Submicron particulate matter (PM1 with an aerodynamic diameter of <1 mm) is a typical pollutant at airports, and the enrichment of heavy metals (HMs) in PM1 poses a great threat to human health. To comprehensively assess the source-specific health effects of PM1-bound HMs in an airport community, PM1 filter samples were collected around the Tianjin Binhai International Airport for 12 h during the daytime and nighttime, both in the spring and summer, and 10 selected HMs (V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) were analyzed. The indicatory elements of aircraft emissions were certified as Zn and Pb, which accounted for more than 60% of the sum concentration of detected HMs. The health risks assessment showed that the total non-cancer risks (TNCRs) of PM1-bound HMs were 0.28 in the spring and 0.23 in the summer, which are lower than the safety level determined by the USEPA, and the total cancer risk (TCR) was 2.37 × 10-5 in the spring and 2.42 × 10-5 in the summer, implying that there were non-negligible cancer risks in the Tianjin Airport Community. After source apportionment with EF values and PMF model, four factors have been determined in both seasons. Consequently, the source-specific health risks were also evaluated by combining the PMF model with the health risk assessment model. For non-cancer risk, industrial sources containing high concentrations of Mn were the top contributors in both spring (50.4%) and summer (44.2%), while coal combustion with high loads of As and Cd posed the highest cancer risk in both seasons. From the perspective of health risk management, targeted management and control strategies should be adopted for industrial emissions and coal combustion in the Tianjin Airport Community.

Qualitative and Quantitative Detection of Typical Reproductive Hormones in Dairy Cows Based on Terahertz Spectroscopy and Metamaterial Technology.

Progesterone (PROG) and estrone (E1) are typical reproductive hormones in dairy cows. Assessing the levels of these hormones in vivo can aid in estrus identification. In the present work, the feasibility of the qualitative and quantitative detection of PROG and E1 using terahertz time-domain spectroscopy (THz-TDS) and metamaterial technology was preliminarily investigated. First, the time domain spectra, frequency domain spectra, and absorption coefficients of PROG and E1 samples were collected and analyzed. A vibration analysis was conducted using density functional theory (DFT). Subsequently, a double-ring (DR) metamaterial structure was designed and simulated using the frequency domain solution algorithm in CST Studio Suite (CST) software. This aimed to ensure that the double resonance peaks of DR were similar to the absorption peaks of PROG and E1. Finally, the response of DR to different concentrations of PROG/E1 was analyzed and quantitatively modeled. The results show that a qualitative analysis can be conducted by comparing the corresponding DR resonance peak changes in PROG and E1 samples at various concentrations. The best R2 for the PROG quantitative model was 0.9872, while for E1, it was 0.9828. This indicates that terahertz spectral-metamaterial technology for the qualitative and quantitative detection of the typical reproductive hormones PROG and E1 in dairy cows is feasible and worthy of in-depth exploration. This study provides a reference for the identification of dairy cow estrus.

Depression, anxiety, and insomnia symptoms among Chinese college students: A network analysis across pandemic stages.

BACKGROUND: As the stages of the COVID-19 pandemic evolved, the symptoms of depression, anxiety, and insomnia have increasingly manifested among Chinese college students. The aim of this study is to investigate the relationships between these symptoms through network analysis among Chinese college students during COVID-19. METHOD: A three-wave cross-sectional survey was conducted at 22 colleges in Guangdong Province, involving 381,152 students during three specific time intervals: T1 (baseline, February 3 to 10, 2020), T2 (19 months after baseline, June 10 to 18, 2021), and T3 (37 months after baseline, March 15 to April 22, 2023). Depression (PHQ-9), anxiety (GAD-7), and insomnia (YSIS) were used separately. We analyzed two key network indices: "Expected influence" and "Bridge expected influence". Network stability was assessed through a case-dropping bootstrap program. RESULT: The effective sample sizes for the three periods were as follows: T1 - 164,101 (103,645 females, 63.2 %), T2 - 86,767 (52,146 females, 60.1 %), and T3 - 130,284 (76,720 females, 58.9 %). Across these three periods, the key central symptoms were "Fatigue" (PHQ4), "Restlessness" (GAD5), "Uncontrollable worrying" (GAD2), "Worry too much" (GAD3) and "Sleep insufficiency" (YSIS6). Notably, "Fatigue" (PHQ4), "Restlessness" (GAD5) and "Irritability" (GAD6) consistently served as bridge symptoms. In the T1 and T2 period, "Motor" (PHQ8) acted as a bridge symptom but weakened in T3. CONCLUSION: Throughout the three periods, the mental health issues among Chinese college students displayed characteristics of somatization within the depression-anxiety-insomnia comorbidity network. Over time, anxiety symptoms appeared to become more prominent. Consequently, this study highlights the importance of accurately identifying and promptly intervening in these core symptoms of mental health among college students, as these symptoms may evolve across different stages of a pandemic.

Remodeling the tumor-immune microenvironment by anti-CTLA4 blockade enhanced subsequent anti-PD-1 efficacy in advanced nasopharyngeal carcinoma.

Sequential immunotherapy has shown certain advantages in malignancy. Here, we aim to evaluate the efficacy of sequential anti-CTLA-4 and anti-PD-1 treatment for recurrent or metastatic nasopharyngeal carcinoma patients (R/M NPC). We retrospectively analysis 2 phase I trial of ipilimumab and camrelizumab in Chinese R/M NPC patients. These patients were initially treated with ipilimumab, a CTLA4 blockade, followed by anti-PD-1 treatment. We observed a durable tumor remission in these patients (mPFS: 12.3 months; mDoR: 20.9 months). Multimodal investigations of biopsy samples disclosed remodeling of tumor-immune microenvironment triggered by ipilimumab. In responders, we found increased tumoral PD-L1/PD-L2 expression and T-cell infiltration after ipilimumab treatment, accompanied by reduced stroma and malignant cell components. In contrast, non-responders exhibited increased B-cell infiltration and increased peripheral CD19 + B cells, suggesting a defective transition from memory B cells to plasma cells. This study proposes that sequential therapy can potentially enhance treatment efficacy in chemotherapy-resistant NPC patients and provides insights into how preexisting anti-CTLA4 blockade can influence subsequent anti-PD-1 efficacy by remodeling the TME. Additionally, our results highlight the need for therapeutic strategies targeting naïve/memory B cells.

Associations of problematic smartphone use with depressive symptoms and suicidal ideation in university students before and after the COVID-19 outbreak: A meta-analysis.

BACKGROUND AND AIM: Problematic smartphone use (PSU) has been suggested to present with depressive symptoms and suicidal ideation (SI) as well as sleep disturbance, lack of social support, and emotional isolation. The aim of this systematic review and meta-analysis was to evaluate the association between PSU with depressive symptoms and SI in university students, and to determine the potential influence of the coronavirus disease 2019 (COVID-19) outbreak. METHODS: Observational studies pertinent to our research were identified through comprehensive searches of the PubMed, Embase, Cochrane Library, and Web of Science databases. To account for potential heterogeneity, the random-effects models were employed to aggregate the findings. RESULTS: Eighteen datasets from 17 case-control studies, including 24,019 university students, were included. Among them, 8,775 (36.5 %) had PSU. A higher prevalence of depressive symptoms (odds ratio [OR]: 2.40, 95 % confidence interval [CI]: 2.19 to 2.63, p < 0.001; prediction interval: 1.95 to 2.96) was observed in university students with higher scores for PSU measures. A subgroup analysis showed a stronger association between PSU and depressive symptoms after the COVID-19 outbreak as compared to that before the outbreak (OR: 2.76 versus 2.16, p for subgroup difference = 0.002), which explained the heterogeneity. The association between PSU and depressive symptoms in university students was similar to those reported in studies from China and other countries, and in studies with different quality scores. Finally, a meta-analysis of three studies suggested that PSU was also associated with the prevalence of SI (OR: 2.18, 95 % CI: 1.77 to 2.68, p < 0.001; I2 = 0 %). CONCLUSION: In university students, PSU may be a risk factor for depressive symptoms and SI, and the association between PSU and depressive symptoms became stronger after the COVID-19 outbreak.

Association between jejunal remodeling in fasting rats and hypersensitivity of intestinal afferent nerves to mechanical stimulation.

Remodeling of Intestinal properties and hypersensitivity of intestinal afferents to mechanical stimulation were previously demonstrated in a fasting rat model. Other studies investigated the association between mechanical and histological remodeling during fasting. This study aimed to further explore the relationship between the jejunal remodeling and intestinal afferent hypersensitivity by combining afferent nerve recordings with histological and mechanical data. Eight male Sprague Dawley rats had no access to food for 7 days (Fasting group). Seven male rats served as controls (Control group). Jejunal segments were studied in vitro in an organ bath for analysis of afferent signaling and for analysis of mechanical and histomorphological parameters. Correlation analyses were done to analyze association between nerve activity (spike rate increase ratio, SRIR) at distension levels of 20, 40 and 80 cmH2O and mechanical stress and histomorphological changes of the jejunal segments. Compared with the Control group, the main findings in jejunal segments in the Fasting group were (1) Most histomorphometry parameters were reduced (P < 0.05-P < 0.001), (2) SRIR values were higher (P < 0.001), (3) The relative numbers of intermuscular and submucosal neurons were increased (P < 0.05-P < 0.01), and (4) SRIR was negatively correlated with intestinal wall thickness, circumferential muscle layer thickness and positively correlated with the inner residual strain, the number of neurons, and the mechanical stress. In conclusion, the fasting-induced histomorphological remodeling (reduced wall thickness and increased relative number of neurons) and biomechanical remodeling (residual strain changes and high stress level) of the intestine in fasting rats were associated with hypersensitivity of intestinal afferents. Afferent hypersensitivity appears to be dependent on stress rather than on strain.

Effect of Tangshen formula on the remodeling of small intestine and colon in Zucker diabetic fatty rats.

Background and aim: Previous study have demonstrated that Tangshen Formula (TSF) could attenuate colonic histomorphological remodeling in the diabetic rat model induced by high fat diet plus low dosage streptozotocin (STZ). However, it is not clear whether TSF has same effect on small intestine and the effect on biomechanical properties of bowel. The aim of this study is to investigate the effect of TSF on histomorphological and biomechanical remodeling of small intestine and colon by using Zucker Diabetic Fatty (ZDF) Rat model. Materials and methods: ZDF rats (obese fa/fa) with blood glucose higher than 11.7 mmol/L were divided into ZDF group (diabetic control group) and ZDF + TSF group (TSF treatment group), the later were intragastrically administered TSF. The ZDF rats (lean fa/+) were served as normal control (ZL) group. The rats in the ZL and ZDF groups were administered with saline. The experimental period covered from 8 weeks to 24 weeks. At the end of experiment, the ileal and colonic segments were studied in vitro. The histomorphometry and biomechanical parameters were measured. Results: Compared with ZL group histomorphologically, the wet weight per unit length, wall thickness, wall area and fractions of total and type I and type III collagen in different layers for both ileum and colon increased in ZDF group. Those increasing parameters were partially inhibited in ZDF + TSF group. Compared with ZL group biomechanically, ZDF and ZDF + TSF groups had smaller opening angle and residual strain in ileum, and bigger opening angle and residual strain in colon. Whereas the wall became softer in circumferential direction and stiffer in longitudinal direction for both ileum and colon. However, no difference of biomechanical parameters was found between ZDF and ZDF + TSF groups. Conclusion: The histomorphological and biomechanical remodeling of ileum and colon were happened in ZDF rats （obese fa/fa）. TSF could partly attenuate ileal and colonic histomorphological remodeling rather than biomechanical remodeling.

Oxidase-like V2C MXene nanozyme with inherent antibacterial properties for colorimetric sensing.

The microbial environment greatly affects the performance of colourimetric sensors, especially the interference of bacteria in the sample detected. This paper reports the fabrication of an antibacterial colorimetric sensor based on V2C MXene synthesized via simple intercalation and stripping. The prepared V2C nanosheets can mimic oxidase activity towards 3,3',5,5'-tetramethylbenzidine (TMB) oxidation without exogenously adding H2O2. Further mechanistic studies showed that V2C nanosheets could effectively activate the oxygen adsorbed on their surface, which in turn causes an increase in the bond length and a decrease in the magnetic moment of oxygen through electron transfer from the nanosheet surface to O2. The V2C nanosheets also exhibited excellent broad-spectrum antibacterial activity through the outbreak of reactive oxygen species. Owing to its unique catalytic activity and the inherent antibacterial ability for mimicking oxidase, a colorimetric sensing platform was developed to effectively determine L-cysteine levels at a detection limit of 30.0 nM (S/N = 3). It is impressive that the detection results of L-cysteine in various complex microbial environments are also very satisfactory. This study broadens the biological use of MXene-based nanomaterials through their satisfactory enzymatic activity and provides a simple and efficient colorimetric strategy for detection techniques used in complex microbial environments.

Compliant human-robot object transfer based on modular 3-axis force sensor for collaborative manufacturing.

The primary motivation of this paper is to present a compliant and cost-effective solution for object transfer between human and robot. The application prospect of this study is robot-human collaboration in manufacturing. To achieve above goals, a novel modular 3-axis force sensor is proposed for the grasping system to achieve interactive force sensing. Compliant object transfer control strategy, which is composed of incremental force control mode and gravity balance control mode, is proposed for object transfer between human and robot. A prototype of underactuated grasping system which is mounted on the proposed modular 3-axis force sensor is fabricated to investigate the effectiveness of the proposed interactive control strategy. Experimental results reveal that the incremental force control mode is suitable for the lighter objects with a higher interactive sensitivity. For transferring heavier objects, the gravity balance control mode is more suitable. In gravity balance control mode, the human hand could achieve a quasi-static equilibrium with the object, and achieve a compliant transfer operation. Due to the above characteristic, the proposed control strategy has the potentials to enhance the object transfer compliance and safety in the human-robot object transfer process.

Prevalence and risk factors for dementia in the Tibetan region: A population-based cross-sectional study.

BACKGROUND: As China's population ages, the nationwide prevalence of dementia is increasing. However, the epidemiology of dementia among the Tibetan population remains unclear. OBJECTIVE: A cross-sectional study was conducted involving 9116 participants aged >50 years in the Tibetan population to investigate the risk factors and prevalence of dementia among this population. Permanent residents of the region were invited to participate, and the response rate was 90.7 %. METHODS: The participants underwent neuropsychological testing and clinical assessments, from which physical measurements (e.g., body mass index, blood pressure), demographic information (e.g., gender, age), and lifestyle details (e.g., family living arrangement, smoking, alcohol arrangement) were recorded. Dementia diagnoses were made using the standard consensus diagnostic criteria. The risk factors of dementia were identified using stepwise multiple logistic regression. RESULTS: The average age of the participants was 63.71 (standard deviation = 9.36), and there were 44.86 % males. The prevalence of dementia was 4.66 %. The multivariate logistic regression analysis revealed that older age, unmarried status, lower education level, obesity, hypertension, diabetes, coronary heart disease, cerebral vascular disease, and HAPC were independently and positively associated with dementia (P < 0.05). However, no association was found between the frequency of religious activities and the prevalence of dementia in this population (P > 0.05). CONCLUSIONS: There exist a number of contributory risk factors for dementia in the Tibetan population, with variations associated with high altitude, religious activities (i.e., scripture turning, chanting, spinning Buddhist beads, and bowing), and dietary habits. These findings suggest that social activities, such as religious activities, are protective factors for dementia.

Impact of family functioning on mental health problems of college students in China during COVID-19 pandemic and moderating role of coping style: a longitudinal study.

BACKGROUND: During the COVID-19 pandemic, college students were required to stay at home and maintain social distance for the entire spring semester of 2020. There is little research on how family functioning influenced mental health problems and how coping styles moderated the relationship between family functioning and mental health problems among college students during their stay-at-home period. METHODS: A total of 13,462 college students (age = 16-29 years) completed four online surveys between February and October 2020, namely the outbreak phase, remission phase, online study phase, and school reopening phase in Guangdong Province, China. Family functioning was assessed by the Family APGAR; coping styles were assessed by the Simplified Coping Style Questionnaire (SCSQ), depression symptoms and anxiety symptoms were evaluated by the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder Scale (GAD-7) respectively. Generalized estimating equations were used to assess associations between variables, the logit link function was used to estimate the odds ratio of different subgroups, the Newton-Raphson method was used to estimate parameters, and the Wald test was used to test the main effect and the interaction effect. RESULTS: The incidence rates of depression increased during the stay-at-home period from 33.87%, 95% CI (29.88%, 38.10%) to 40.08% 95% CI (35.76%, 44.55%) after schools reopened, χ2 = 193.68, p < 0.001. The incidence rates of anxiety increased from 17.45%, 95% CI (14.59%, 20.73%) to 26.53%, 95% CI (16.94%, 23.67%) over the entire period, χ2 = 195.74, p < 0.001. The percentages of students with highly functional, moderately dysfunctional and severely dysfunctional family functioning were 48.23%, 43.91 and 7.86% at T1 and 46.20%, 45.28%, and 8.52 at T4, respectively. The percentage of subjects with active coping style was 23.9%, negative coping style was 17.4%, strong response coping was 26.9%, and weak response coping was 31.7%. The incidence rate of depression and anxiety for different family functioning groups varied at different time points, and the interaction effect was significant (χ2 = 52.97, p < 0.001 and χ2 = 51.25, p < 0.001, respectively). The incidence rate of depression and anxiety for different family functioning groups with different coping styles also varied at different time points, the interaction effect was likewise significant (χ2 = 862.09, p < 0.001 and χ2 = 583.29, p < 0.001, respectively). CONCLUSIONS: Having a severely dysfunctional family and a negative coping style increase the incidence rates of depression and anxiety. These findings highlight the importance of paying special attention to college students' family functioning and promoting appropriate coping strategies during and after COVID-19.

An Unusual College Experience: 16-Month Trajectories of Depressive Symptoms and Anxiety among Chinese New Undergraduate Students of 2019 during the COVID-19 Pandemic.

BACKGROUND: This study examines the trajectories of the mental health conditions of 13,494 new undergraduate students who enrolled in 2019 in China from the beginning of the pandemic to the local recurrence of the pandemic, and found factors which may be associated with diverse trajectories. METHODS: The trajectories of depression-anxiety outcomes were modeled using the growth mixture model. The multinomial logistic regression model was used to identify variables associated with different trajectory groups. RESULTS: Both depression and anxiety in the new college students slightly increased during the 16-month period. The slopes of depression and anxiety were lower after the local outbreak. From the trajectories of depression and anxiety, five heterogeneous groups were identified: low-stable (64.3%), moderate-increased (18.2%), high-stable (11.1%), recovery (4.5%), and rapid-increased (1.8%). Environmental, somatic, and social factors were used to differentiate the low-stable group from the other groups. We found that college students with female gender, more conflict with parents, and feelings of loneliness during the pandemic were more likely to enter a high stability trajectory compared to a recovery trajectory. CONCLUSION: Most participants showed a stable mental health status, while others experienced deteriorating or chronic mental health problems, especially those who had sleep disturbances, less social support before the pandemic, or conflicts with parents during the pandemic. These students may need additional support and monitoring from college mental health providers to improve their wellbeing.

Normative values of hand grip strength in a large unselected Chinese population: Evidence from the China National Health Survey.

BACKGROUND: Hand grip strength (HGS) is a powerful indicator of sarcopenia and other adverse health outcomes. Normative values for HGS for general Chinese people with a broad age spectrum are lacking. This study aims to establish normative values of HGS and explore the correlations between HGS and body composition among unselected people aged 8-80 in China. METHODS: From 2012 to 2017, 39 655 participants aged 8-80 years in the China National Health Survey were included. Absolute HGS was measured using a Jamar dynamometer. The relative HGS was normalized by body mass index. Body composition indexes included body mass index, body fat percentage, muscle mass, fat mass index (FMI) and muscle mass index (MMI). Sex-specific smoothed centile tables for the P1 , P5 , P25 , P50 , P75 , P95 and P99 centiles of HGS and body composition were generated using lambda-mu-sigma method. The correlations between muscle strength and body composition were estimated by partial Spearman correlation analysis. RESULTS: The median values (25th and 75th percentile) of HGS in boys and girls (8-19 years old) were 22 (14, 34) kg and 18 (12, 22) kg, respectively; in men and women aged 20-80 were 39 (33, 44) kg and 24 (20, 27) kg, respectively. Values of upper and lower HGS across ages had three periods: an increase to a peak in the 20 s in men (with the 5th and 95th values of 30 and 55 kg, respectively) and 30 s in women (with the 5th and 95th values of 18 and 34 kg, respectively), preservation through midlife (20s-40 s), and then a decline after their 50 s. The lowest HGS values in both sexes were in the 70- to 80-year-old group, with the 5th and 95th percentile values of 16 and 40 kg in men, and 10 and 25 kg in women. There were substantial sex differences in body composition in the life course (all P values <0.001). In ageing, the decrease of muscle strength was faster than that of muscle mass in both sexes. The correlations between muscle mass and HGS were most robust than other correlations, especially in women (0.68 vs. 0.50), children and adolescents. CONCLUSIONS: Our study established the age- and sex-specific percentile reference values for hand grip strength in an unselected Chinese population across a broad age-spectrum. The rich data can facilitate the practical appraisal of muscle strength and promote early prediction of sarcopenia and other impairments associated with neuromuscular disorders.

The association between muscle-to-fat ratio and cardiometabolic risks: The China National Health Survey.

BACKGROUND: The relationship between muscle mass and fat mass might be an indicator to assess the cardiometabolic risk independently from overweight/obesity, but evidence from a representative general Chinese population is lacking. OBJECTIVE: To understand the age- and sex-specific associations between muscle-to-fat ratio (MFR) and cardiometabolic risks in Chinese population. METHODS: 31,178 (12,526 men and 18,652 women) subjects from the China National Health Survey were included. Muscle mass and fat mass were assessed by a bioelectrical impedance device. MFR was calculated as muscle mass divided by fat mass. Systolic blood pressure (SBP) and diastolic blood pressure (DBP), serum lipids, fasting plasma glucose and serum uric acid were measured. General linear regressions, quantile regressions and restricted cubic-spline (RCS) regressions were applied to assess the effect of MFR on cardiometabolic profiles. RESULTS: Per unit increase of MFR was associated with a 0.631 (0.759-0.502) mmHg SBP decrease in men, 2.648 (3.073-2.223) in women; 0.480 (0.568-0.392) mmHg DBP decrease in men, 2.049 (2.325-1.774) in women; a 0.054 (0.062-0.046) mmol/L total cholesterol decrease in men, 0.147 (0.172-0.122) in women; 0.084 (0.098-0.070) mmol/L triglycerides decrease in men, 0.225 (0.256-0.194) in women; a 0.045 (0.054-0.037) mmol/L low-density lipoprotein decrease in men, 0.183 (0.209-0.157) in women; a 2.870 (2.235-3.506) µmol/L serum uric acid decrease in men, 13.352 (14.967-11.737) in women; and a 0.027 (0.020-0.033) mmol/L high-density lipoprotein increase in men, 0.112 (0.098-0.126) mmol/L in women. The effect in overweight/obese people was much significant than in under/normal weight counterparts. The RCS curves revealed both linear and non-linear relationships between increased MFR and lower cardiometabolic risk. CONCLUSIONS: Muscle-to-fat ratio is independently associated with multiple cardiometabolic parameters among Chinese adults. Higher MFR is related with better cardiometabolic health, and the effect is much significant in overweight/obese people and women.

Intolerance of uncertainty and anxiety among college students during the re-emergence of COVID-19: Mediation effects of cognitive emotion regulation and moderation effects of family function.

OBJECTIVE: In June 2021, the COVID-19 spread again in the community, and residents had to face the impact of the outbreak again after 276 days, none of the local cases in Guangdong Province, China. The purpose of this study was to investigate the mechanisms underlying the relationship between intolerance of uncertainty (IU) and anxiety in college students in non-epidemic area during the periods of re-emergence of COVID-19. METHODS: A survey was conducted among 86,767 college students in Guangdong Province, China from 10 to 18 June 2021, information on the Intolerance of Uncertainty Scale (IUS), General Anxiety Disorder-7 (GAD-7), Cognitive Emotion Regulation Questionnaire (CERQ) and Family APGAR Index were collected. Five moderation and mediation models were analyzed using latent moderated structural equations. RESULTS: The results showed that IU was positively related to anxiety (r = 0.42, p < 0.000). After controlling for age and gender, latent moderated structural equations indicated that catastrophizing mediated the relationship between IU and anxiety, and family function acted as a moderator in this relationship. Further analyses indicated that IU directly affected anxiety and had indirect effects on anxiety by catastrophizing. This relationship was weaker among college students who reported lower family function. CONCLUSION: This study provides practical implications for designing intervention strategies to reduce anxiety in college students when the epidemic re-emerges.

Differential influences of serum vitamin C on blood pressure based on age and sex in normotensive individuals.

Aim: Hypertension is among the most prevalent chronic diseases with diverse etiology, affecting over 1 billion people globally. In numerous studies, vitamin C inversely correlated with blood pressure and was suspected to have antihypertensive properties. Currently, there is conflicting evidence regarding the relationship between vitamin C and blood pressure, with most studies being conducted on hypertensive subjects. The principal objective of this project was to investigate the relationship between vitamin C and blood pressure in normotensive adult subjects. Methods: A total of 2,533 individuals aged 20 years and above were enrolled in the present study from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Outcome variables were systolic blood pressure (SBP) and diastolic blood pressure (DBP). Serum vitamin C was regarded as an independent variable. EmpowerStats software and R (version 3.4.3) were used to examine the association between vitamin C and SBP or DBP. Results: Vitamin C was reversely correlated with both SBP (ß = -0.02, 95% CI: -0.03 to -0.00, p = 0.0306) and DBP (ß = -0.02, 95% CI: -0.04 to -0.01, p = <0.0011) after adjusting all covariates. This reverse relationship may be affected by a number of factors, including a person's gender, age, race, and ethnicity. A U-shaped association between vitamin C and SBP in females and an inverted one between vitamin C and DBP in males were detected, respectively. We further calculated the inflection points at 90.3 µmol/L for females and 40 µmol/L for males. It is somewhat surprising that a reverse U-shaped distribution between vitamin C and SBP and DBP in people over 50 was detected, and the point of inflection of vitamin C were all located at 40 µmol/L. Conclusion: Vitamin C was negatively correlated with both SBP and DBP in this cross-sectional analysis. However, a U-shaped relationship and an inverted one were also observed in certain people, which implied that, though vitamin C is considered a vital antioxidant, maintaining vitamin C at appropriate levels may be beneficial according to different populations.