Ratiometric electrogenerated chemiluminescence sensing microRNA based on electrochemically controlled release of lucigenin from silica/chitosan/lucigenin nanoparticles.

The dye-doped silica nanoparticles-based electrogenerated chemiluminescence (ECL) has been widely explored for analytical purposes due to its high sensitivity, simplicity and wide dynamic concentration range. However, only a few of dye molecules located at the near surface of nanoparticles can participate in the ECL reaction due to the poor conductivity of silica nano-matrix. In addition, the ECL signal is easy to be affected by environmental interference, which results in poor accuracy. Herein, a ratiometric ECL sensing method is established based on the electrochemically controlled release of lucigenin molecules from silica/chitosan/lucigenin composite nanoparticles (Lu/CS NPs) with the aid of sulfide ions. Firstly, H+ produced from the electrochemical oxidation of HS- ions can combine with SiO- and displace lucigenin from Lu/CS NPs. The released lucigenin molecules react with the reactive oxygen species (ROS) generated from the electroreduction of dissolved oxygen to produce the cathodic ECL signal. In addition, the excited elemental sulfur from the electrooxidation of HS- ions transfers its energy to lucigenin molecules and makes them be excited to produce energy-transfer anodic ECL signal. Based on these findings, a ratiometric ECL sensor is developed taking the anodic ECL intensity of lucigenin as a reference signal for the cathodic ECL of lucigenin. The proposed ratiometric ECL sensor has been successfully applied to the detection of let-7a with a wide linear range of 0.1-9.0 pM, a low detection limit of 28 fM, high selectivity and good reproducibility. Moreover, the developed approach was used to detect let-7a in human serum composite samples with good recoveries.

Sedentary Behavior and Physical Frailty Among Rural Older Adults in China: The Moderating Effect of Social Isolation.

OBJECTIVES: Few studies have explored the mechanisms underlying the relationship between sedentary behavior and physical frailty. The aim of this study was to investigate the moderating effect of social isolation on the association between sedentary behavior and physical frailty among older adults in rural China. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Data were from 3238 individuals aged ≥60 years from rural areas in China. METHODS: Binary logistic regression was used to explore the association between sedentary behavior and physical frailty and the moderating effect of social isolation. RESULTS: The prevalence of physical frailty was 18.7% among the older adults, and 17.0% of them were sedentary for ≥8 h/d. Compared with older adults with sedentary behavior for <4 h/d, participants with sedentary behavior for ≥8 h/d were more likely to suffer from physical frailty [odds ratio (OR), 2.26; 95% CI, 1.57-3.27]. We found that social isolation may aggravate this relationship (OR, 3.31; 95% CI, 2.06-5.32), especially for rural older adults who were sedentary for ≥8 h/day. CONCLUSION AND IMPLICATIONS: More sedentary behavior was associated with higher risk of physical frailty, which was especially apparent among older adults with social isolation, suggesting that sedentary older people who experienced social isolation were more vulnerable to physical frailty. Decreasing sedentary behavior in older adults and encouraging them to participate in interactive social activities could help prevent physical frailty.

Human-Guided Reinforcement Learning With Sim-to-Real Transfer for Autonomous Navigation.

Reinforcement learning (RL) is a promising approach in unmanned ground vehicles (UGVs) applications, but limited computing resource makes it challenging to deploy a well-behaved RL strategy with sophisticated neural networks. Meanwhile, the training of RL on navigation tasks is difficult, which requires a carefully-designed reward function and a large number of interactions, yet RL navigation can still fail due to many corner cases. This shows the limited intelligence of current RL methods, thereby prompting us to rethink combining RL with human intelligence. In this paper, a human-guided RL framework is proposed to improve RL performance both during learning in the simulator and deployment in the real world. The framework allows humans to intervene in RL's control progress and provide demonstrations as needed, thereby improving RL's capabilities. An innovative human-guided RL algorithm is proposed that utilizes a series of mechanisms to improve the effectiveness of human guidance, including human-guided learning objective, prioritized human experience replay, and human intervention-based reward shaping. Our RL method is trained in simulation and then transferred to the real world, and we develop a denoised representation for domain adaptation to mitigate the simulation-to-real gap. Our method is validated through simulations and real-world experiments to navigate UGVs in diverse and dynamic environments based only on tiny neural networks and image inputs. Our method performs better in goal-reaching and safety than existing learning- and model-based navigation approaches and is robust to changes in input features and ego kinetics. Furthermore, our method allows small-scale human demonstrations to be used to improve the trained RL agent and learn expected behaviors online.

A Carbonate-Involved Amplification Strategy for Cathodic Electrochemiluminescence of Luminol Triggered by the Catalase-like CoO Nanorods.

The lumiol-O2 electrochemiluminescence (ECL) system constantly emits bright light at positive potential. Notably, compared with the anodic ECL signal of the luminol-O2 system, the great virtues of cathodic ECL are that it is simple and causes minor damage to biological samples. Unfortunately, little emphasis has been paid to cathodic ECL, owing to the low reaction efficacy between luminol and reactive oxygen species. The state-of-the-art work mainly focuses on improving the catalytic activity of the oxygen reduction reaction, which remains a significant challenge. In this work, a synergistic signal amplification pathway is established for luminol cathodic ECL. The synergistic effect is based on the decomposition of H2O2 by catalase-like (CAT-like) CoO nanorods (CoO NRs) and regeneration of H2O2 by a carbonate/bicarbonate buffer. Compared with Fe2O3 nanorod (Fe2O3 NR)- and NiO microsphere-modified glassy carbon electrodes (GCEs), the ECL intensity of the luminol-O2 system is nearly 50 times stronger when the potential ranged from 0 to -0.4 V on the CoO NR-modified GCE in a carbonate buffer solution. The CAT-like CoO NRs decompose the electroreduction product H2O2 into OH· and O2·-, which further oxidize HCO3- and CO32- to HCO3· and CO3·-. These radicals very effectively interact with luminol to form the luminol radical. More importantly, H2O2 can be regenerated when HCO3· dimerizes to produce (CO2)2*, which provides a cyclic amplification of the cathodic ECL signal during the dimerization of HCO3·. This work inspires developing a new avenue to improve cathodic ECL and deeply understand the mechanism of a luminol cathodic ECL reaction.

Association of Sensory Impairment With Institutional Care Willingness Among Older Adults in Urban and Rural China: An Observational Study.

Background and Objectives: An aging population has contributed to increasing rates of sensory impairment (SI) among older adults and a boom in institutional elder care. However, little is known regarding the association between SI and institutional care willingness. This study identified the association between SI and institutional care willingness among older adults living both in urban and rural China. Research Design and Methods: This was an observational study using the sixth National Health Service Survey of Shandong Province, China, in 2018. A total of 8 583 individuals aged ≥60 years were included. The primary outcome was institutional care willingness. Self-reported SI was categorized as vision impairment (VI), hearing impairment (HI), and dual sensory impairment (DSI). We used multivariable logistic regression models to estimate the association between SI and institutional care willingness, stratified by the place of residence. Results: The overall proportion of older adults with institutional care willingness was 7.8%. In fully adjusted models, older adults with HI only (odds ratio [OR] = 1.57, 95% confidence interval [CI]: 1.12-2.20) or DSI (OR = 1.68, 95% CI: 1.14-2.49) were more likely to show institutional care willingness than those without SI in urban areas, but no significant associations between VI only (OR = 0.95, 95% CI: 0.68-1.31), HI only (OR = 0.99, 95% CI: 0.73-1.34), or DSI (OR = 0.95, 95% CI: 0.68-1.31) and institutional care willingness were observed among rural older adults. Discussion and Implications: Our results underscore that the relationship between SI and institutional care willingness varied by place of residence, and provide a reference for making targeted and appropriate endowment policies. Improving the quality of institutional elder care is vital for urban older adults with SI, whereas community-based care might be more appropriate for rural older adults with SI.

Sex Difference in the Association Between Sedentary Behavior and Sleep Quality: A Longitudinal Study Among Older Adults in Rural China.

OBJECTIVES: Sleep quality plays a vital role in maintaining health in older adults. Sedentary behavior may be a risk factor for poor sleep quality in older adults. This study aimed to explore the relationship between sedentary behavior and sleep quality among older adults in rural China and determine whether there is a sex difference in this association. DESIGN: A longitudinal design. The data used in this study were obtained from the Shandong Rural Elderly Health Cohort (wave 1: 2019, wave 2: 2020). SETTING AND PARTICIPANTS: Data were from 2731 individuals aged ≥60 years from rural areas in China. METHODS: Sleep quality was assessed using the Pittsburgh Sleep Quality Index. Sedentary behavior and control variables were measured using self-reported questions. Multivariable logistic regression and generalized estimating equations were used to assess the associations. RESULTS: After full adjustment, the association between sedentary behavior and poor sleep quality was statistically significant [odds ratio (OR) 1.49, 95% CI 1.20-1.85]. Specifically, a longer sedentary time was associated with worse subjective sleep quality, less sleep latency, and lower habitual sleep efficiency (OR 1.39-1.58). A significant association was observed in women but not men. CONCLUSIONS AND IMPLICATIONS: Older adults who spend more time engaging in sedentary activities have poorer sleep quality and more sleep problems. Prolonged sedentary time is more detrimentally associated with poor sleep quality in women than men. There is a need for tailored exercise prescriptions and guidelines to stimulate older adults of different sexes to change their sedentary behavior, which may improve sleep quality in older adults.

Prevalence and risk factors of latent tuberculosis infection among college students: a systematic review and meta-analysis.

OBJECTIVES: College students are at increased risk of tuberculosis (TB), which increases their likelihood of developing latent tuberculosis infections (LTBI). This study aimed to estimate the pooled prevalence of LTBI and identify its risk factors. STUDY DESIGN: Systematic review and meta-analysis. METHODS: We searched PubMed, Embase, Scopus, Web of Science, CNKI, Wanfang and CBM databases (10 March 2022) for studies published in any language. The pooled prevalence of LTBI was estimated using random effects methods. Factors associated with LTBI were evaluated by determining standardised mean difference (SMD) with 95% confidence interval (CI). All analyses were performed using the Stata 15.1. RESULTS: A total of 50 studies from 18 countries were included, with 44 tuberculin skin test (n = 623,732) and 19 interferon gamma release assay (n = 38,266) estimates. The prevalence of a positive tuberculin skin test was 20% (95% CI: 17-23%), and the prevalence of a positive interferon gamma release assay was 9% (95% CI: 7%-11%) among college students. Older age (SMD: 1.67, 95% CI: 1.31-2.13), no Bacillus Calmette-Guérin vaccination/scar (SMD: 1.51, 95% CI: 1.06-2.16), contact with TB cases (SMD: 1.34, 95% CI: 1.11-1.62), clinical training (SMD: 1.93, 95% CI: 1.65-2.26) and overweight/obesity (SMD: 1.17, 95% CI: 1.06-1.30) were associated with a higher prevalence of LTBI. Sex was not associated with LTBI prevalence. CONCLUSION: College students have an increased risk of LTBI, although it varies by geographical area. This meta-analysis provides evidence of risk factors for LTBI in college students. Infection control measures should be conducted for college students with LTBI.

Pet ownership and cognitive frailty among Chinese rural older adults who experienced a social loss: Is there a sex difference?

BACKGROUND: The loss of a spouse (widowed or divorced) is one of the most common forms of social loss in older adults. However, evidence is limited regarding whether social loss is associated with cognitive frailty. Maintaining pets has become increasingly popular. Despite its health benefits, little is known about whether pet ownership can buffer cognitive frailty in older adults facing social loss. Here, we examined the role of pet ownership in the relationship between social loss and cognitive frailty among males and females older adults living in rural China. METHODS: A total of 2638 rural older adults were analysed. Binary logistic regression analyses were conducted to explore risk or protective factors associated with cognitive frailty. Participants were categorised into four groups according to social loss and pet ownership assessment: (i) no social loss + own pet, (ii) no social loss + no pet, (iii) social loss + own pet, and (iv) social loss + no pet. Binary logistic regression was also performed to examine the interaction effects of social loss and pet ownership on cognitive frailty stratified by sex. RESULTS: Regardless of pet ownership, spousal loss was associated with cognitive frailty for men and women. Female participants who experienced loss without a pet had a significantly higher risk of cognitive frailty. However, we did not observe a significant association between pet ownership and cognitive frailty among men who experienced loss. CONCLUSIONS: Our findings highlight the buffering effect of pet ownership on cognitive frailty in older women experiencing social loss. This implies that targeted support for older adults of different sexes who experienced social losses may be effective in preventing cognitive frailty in rural China.

Longitudinal relationship between sensory impairments and depressive symptoms in older adults: The mediating role of functional limitation.

BACKGROUND: The underlying mechanism between sensory impairments (SIs) and depressive symptoms among Chinese older adults is not well understood. This study aims to explore the mediating role of functional limitation on the longitudinal relationship between SIs and depressive symptoms among older adults in China. METHODS: A total of 4130 older adults who participated in the 3-year follow-up China Health and Retirement Longitudinal Study (CHARLS) were included in the analysis. The hierarchical multiple linear regression model and nonparametric bootstrapping method were employed to explore the relationship between SIs and depressive symptoms, and the mediating role of functional limitation in this link. RESULTS: The prevalence of self-reported hearing impairment (HI) only, vision impairment (VI) only, and dual sensory impairment (DSI) at baseline were 5.7%, 22.2%, and 58.6%, respectively. After adjusting for controlling variables, older adults with DSI had significantly higher levels of depressive symptoms compared with those without SIs at baseline (ß = .07, p = .005). The magnitude of mediation effect from DSI to depressive symptoms via functional limitation was a*b = 0.060 (BCa 95% confidence interval: 0.031-0.094). CONCLUSIONS: Functional limitation partially mediated the relationship between DSI and depressive symptoms among Chinese older adults. Interventions of DSI and functional limitation should be included in depressive symptoms prevention among older adults in China.

Prevalence and risk factors of posttraumatic stress disorder among Chinese shidu parents: A systemic review and meta-analysis.

BACKGROUND: Losing the only child is an extremely distressful life event for parents. Previous studies indicated that shidu parents were more vulnerable to develop posttraumatic stress disorder (PTSD). This study aims to calculate the pooled prevalence of PTSD and identify its risk factors. METHOD: We conducted a systematic literature search in PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), Wanfang databases, Vip databases. We performed a meta-analysis using random effects models to calculate the pooled PTSD in shidu parents. Associated factors for PTSD was evaluated by determining standardized mean difference (SMD) with 95% CIs. All analyses were performed using the Stata 16.0. RESULTS: Eight articles (covering 2,722 shidu parents) were included in this study. The pooled prevalence of PTSD was 46.8% (95%CI: 33.2%-60.3%) among Chinese shidu parents. Female (SMD[95%CI]: 0.41[0.20, 0.62]), higher education level (SMD[95%CI]: 0.15[0.03, 0.28]), lower income (SMD[95%CI]: 0.33[0.13, 0.53]), losing a daughter (SMD[95%CI]: 0.16[0.03, 0.28]) and shorter time since loss (SMD[95%CI]: 0.24[0.07, 0.40]) were significantly associated with a higher PTSD prevalence. Registered residence, cause of death, age of the child, and having a grandchild were not associated with PTSD. LIMITATIONS: Some variables included in this meta-analysis were only measured twice, which limited the conclusions to some extent. CONCLUSION: This meta-analysis indicated that nearly half of shidu parents experienced PTSD and provided evidence of risk factors for PTSD in shidu parents. Further research is suggested to determine how these factors interact. Effective interventions should be conducted to shidu parents with PTSD.

Reduction of pesticide residues on fresh vegetables with electrolyzed water treatment.

Degradation of the 3 pesticides (acephate, omethoate, and dimethyl dichloroviny phosphate [DDVP]) by electrolyzed water was investigated. These pesticides were commonly used as broad-spectrum insecticides in pest control and high-residual levels had been detected in vegetables. Our research showed that the electrolyzed oxidizing (EO) water (pH 2.3, available chlorine concentration:70 ppm, oxidation-reduction potential [ORP]: 1170 mV) and the electrolyzed reducing (ER) water (pH 11.6, ORP: -860 mV) can reduce the pesticide residues effectively. Pesticide residues on fresh spinach after 30 min of immersion in electrolyzed water reduced acephate by 74% (EO) and 86% (ER), omethoate by 62% (EO) and 75% (ER), DDVP by 59% (EO) and 46% (ER), respectively. The efficacy of using EO water or ER water was found to be better than that of using tap water or detergent (both were reduced by more than 25%). Besides spinach, the cabbage and leek polluted by DDVP were also investigated and the degradation efficacies were similar to the spinach. Moreover, we found that the residual level of pesticide residue decreased with prolonged immersion time. Using EO or ER water to wash the vegetables did not affect the contents of Vitamin C, which inferred that the applications of EO or ER water to wash the vegetables would not result in loss of nutrition.