Neighborhood deprivation and depressive symptoms in Chinese adolescents: Mediated by parenting styles and moderated by relative family status.

BACKGROUND: Previous research has shown that neighborhood and family have a crucial impact on adolescent mental health. However, limited research has been conducted on the intersection between neighborhood and family and the mechanisms behind its influence. This study investigates the direct and indirect associations between neighborhood deprivation and adolescent depressive symptoms through parental responsiveness and demandingness. The heterogeneity of neighborhood effects, varying across different relative family statuses, is also discussed. METHODS: Using a sample (n = 6775) from the two waves of the China Education Panel Survey, this study used moderated mediation analysis to analyze simultaneously the mediation roles of parental responsiveness and demandingness and the moderating effect of relative family status. RESULTS: Neighborhood deprivation (W1) was positively associated with adolescent depressive symptoms (W2). Parental responsiveness (W2) rather than demandingness (W2) partially mediated the relationship between neighborhood deprivation and adolescent depression. Additionally, relative family status moderated the direct relationship between neighborhood deprivation and depression and the indirect relationship through parental responsiveness. LIMITATIONS: First, Neighborhood deprivation in this study was self-reported. Second, relative family status was a single-item measure. Third, only family and neighborhood environments were discussed in this study. Finally, long-term changes in the mental health of adolescents in poor neighborhoods could not be captured in this study. CONCLUSIONS: The results highlight that neighborhood deprivation and relative family status can influence adolescent mental health individually and intersectively. This study also contributes to a more nuanced understanding of parenting styles in the Chinese context.

Multi-strand Fibers with Hierarchical Helical Structures Driven by Water or Moisture for Soft Actuators.

Smart actuators that combine excellent mechanical properties and responsive actuating performance like biological muscles have attracted considerable attention. In this study, a water/humidity responsive actuator, consisting of multi-strand carboxyl methyl cellulose (CMC) fibers with helical structures, was prepared using wet-spinning and twisting methods. The results showed that owing to the multi-strand structure, the actuator consisted of one-, two-, three-, and four-strand helical fibers, thus achieving a combination of high strength (∼27 MPa), high toughness (>10.34 MJ/m3), and large load limit (>0.30 N), which enable the actuator to theoretically withstand a weight that is at least 20,000 times its weight. Meanwhile, owing to the excellent moisture-responsive ability of CMC, the actuator, with a 5 g load, could achieve untwisting motion. Additionally, its maximum speed was approximately 2158 ± 233 rpm/m under water stimulation, whereas the recovery speed could reach 804 ± 44 rpm/m. Moreover, this untwisting-recovery reversible process was cyclic, whereas the shape and the actuating speed of the actuator remained stable after more than 150 cycles. The actuator improved the load limit that the fiber could withstand when driving under stimulation, thereby enabling the actuator to lift or move heavy objects like human muscles when executing spontaneously under external stimuli. This result shows considerable potential applications in artificial muscles and biomimetic robots.

Perceived academic stress and depressive symptoms among Chinese adolescents: A moderated mediation analysis of overweight status.

BACKGROUND: Previous research has indicated the association of perceived stress with mental health problems. In China, Confucian collectivism and an exam-centered culture encourage parents to have high educational expectations that impose great pressure on their children's learning. However, limited research has focused on adolescents' perceptions of the negative consequences of academic stress stemming from their parents' educational expectations. This study addressed this research gap by examining the direct effect of adolescents' perceptions of academic stress on their depressive symptoms and the indirect effects of both parent-child communication and interaction. We further explored the pathway differences between overweight and non-overweight adolescents. METHODS: By using a sample (n = 6,566) from the first two waves of the China Education Panel Survey, moderated mediation analysis was performed to simultaneously analyze the mediating roles of parent-children communication and parent-children interaction and the moderating role of adolescent overweight status. RESULTS: Adolescents' perceived academic stress (W1) was positively associated with their depressive symptoms (W2). This association was partially mediated by both parent-child communication (W1) and parent-child interaction (W1). Moreover, adolescent overweight status significantly moderated the paths between the adolescents' perceived academic stress and their depressive symptoms, between their perceived academic stress and parent-child interaction, and the indirect relationship via parent-child interaction. LIMITATIONS: Some measurement biases including self-reported, unverified, and single-item measures, alongside not considering all variations in controlled variables should be noted. CONCLUSION: The study's findings identify the significant roles of parent-child communication and parent-children interaction in contemporary China and indicate overweight adolescents' susceptibility to stress.

Embryonic Ketamine Produces a Downregulation of Prefrontal Cortex NMDA Receptors and Anxiety-Like Behavior in Adult Offspring.

Previous studies have focused on the effects of N-methyl-D-aspartate receptor (NMDAR) blockade on neonates, but little is known about the effect of the embryonic NMDAR blockade on offspring, especially the long-lasting effect, on behavior in adulthood. Here, pregnant rats at E14 were treated with ketamine for 5 successive days and undergone multiple behavior tests, electrophysiology experiment, and Western blotting analysis to detect the alterations in their offspring. We found that embryonic ketamine treatment induced anxiety-like behavior in adulthood (8-week old) offspring. At the same period, we observed an attenuation of NMDA-evoked current as well as decreased NR2A and NR2B membrane expression in the prefrontal cortex (PFC), but not in the hippocampus or amygdala. Selective inhibition experiments with NR2A or NR2B specific antagonists suggested that embryonic ketamine treatment induced NMDAR current attenuation was likely mediated by changes in NR2A subunit. Moreover, at the 4-week time point, NMDA-evoked current was unchanged in PFC, but enhanced in hippocampal CA1 area, which may be caused by the over expression of NR2B in the hippocampus at 4-week time. Furthermore, NR2B knockdown, by using NR2B-shRNA lentivirus, in the hippocampal CA1 area at 3-4-week of age significantly rescued the decrease in NR2A expression in the PFC and anxiety-like behavior observed at 8-week adult offspring rats. In conclusion, our results suggested that embryonic ketamine treatment induced anxiety-like behavior and the downregulation of NMDAR function in PFC in the adulthood period of offspring, which might result from the enhanced function of NMDARs in the hippocampus at the 4-week juvenile time point.

KCC2 downregulation facilitates epileptic seizures.

GABAA receptor-mediated inhibition depends on the maintenance of low level intracellular [Cl-] concentration, which in adult depends on neuron specific K+-Cl- cotransporter-2 (KCC2). Previous studies have shown that KCC2 was downregulated in both epileptic patients and various epileptic animal models. However, the temporal relationship between KCC2 downregulation and seizure induction is unclear yet. In this study, we explored the temporal relationship and the influence of KCC2 downregulation on seizure induction. Significant downregulation of plasma membrane KCC2 was directly associated with severe (Racine Score III and above) behavioral seizures in vivo, and occurred before epileptiform bursting activities in vitro induced by convulsant. Overexpression of KCC2 using KCC2 plasmid effectively enhanced resistance to convulsant-induced epileptiform bursting activities in vitro. Furthermore, suppression of membrane KCC2 expression, using shRNAKCC2 plasmid in vitro and shRNAKCC2 containing lentivirus in vivo, induced spontaneous epileptiform bursting activities in vitro and Racine III seizure behaviors accompanied by epileptic EEG in vivo. Our findings novelly demonstrated that altered expression of KCC2 is not the consequence of seizure occurrence but likely is the contributing factor.

Dual relaxation and structural changes under uniaxial strain in main-chain smectic-C liquid crystal elastomer.

The relationship between strain-dependent macroscopic elastic behavior and the changes in microscopic structure of the smectic-C liquid crystal elastomer (LCE), C11MeHQSi8 were investigated using synchrotron X-ray studies. At very low strains ε ≤ 0.2, the smectic layers are randomly oriented. As the strain increases beyond 0.2, the smectic layers reorient and become parallel to the direction of the applied strain. The polydomain to monodomain (P-M) transition accompanied by the formation of chevron structure ensues for ε > 0.2 and is nearly complete for ε = 0.7. The chevron structure relaxes after the applied strain changes, with a time constant τα ∼ 45 min while the orientation order parameters of the mesogenic and elastomeric components gradually increase and saturate at 0.83 and 0.4, respectively at ε = 1.7 which is near the end of the plateau region. Relaxation rates τα for the tilt angle and τd corresponding to the smectic layer spacing both become about 10 times faster when the strain exceeds 0.7. The LCE remains "locked" into the monodomain state and retains 90% and 80% values of α and S, respectively for 24 hours after the applied strain is removed. The viscoelastic properties of the liquid crystal appear to dominate the equilibration process at low strains while the elastomeric properties control the system's response at high strains.

Activation of extrasynaptic GABA(A) receptors inhibits cyclothiazide-induced epileptiform activity in hippocampal CA1 neurons.

Extrasynaptic GABA(A) receptors (GABA(A)Rs)-mediated tonic inhibition is reported to involve in the pathogenesis of epilepsy. In this study, we used cyclothiazide (CTZ)-induced in vitro brain slice seizure model to explore the effect of selective activation of extrasynaptic GABA(A)Rs by 4,5,6,7-tetrahydroisoxazolo[5,4-c] pyridine-3-ol (THIP) on the CTZ-induced epileptiform activity in hippocampal neurons. Perfusion with CTZ dose-dependently induced multiple epileptiform peaks of evoked population spikes (PSs) in CA1 pyramidal neurons, and treatment with THIP (5 µmol/L) significantly reduced the multiple PS peaks induced by CTZ stimulation. Western blot showed that the δ-subunit of the GABA(A)R, an extrasynaptic specific GABA(A)R subunit, was also significantly down-regulated in the cell membrane 2 h after CTZ treatment. Our results suggest that the CTZ-induced epileptiform activity in hippocampal CA1 neurons is suppressed by the activation of extrasynaptic GABA(A)Rs, and further support the hypothesis that tonic inhibition mediated by extrasynaptic GABA(A)Rs plays a prominent role in seizure generation.

U-shape suppressive effect of phenol red on the epileptiform burst activity via activation of estrogen receptors in primary hippocampal culture.

Phenol red is widely used in cell culture as a pH indicator. Recently, it also has been reported to have estrogen-like bioactivity and be capable of promoting cell proliferation in different cell lines. However, the effect of phenol red on primary neuronal culture has never been investigated. By using patch clamp technique, we demonstrated that hippocampal pyramidal neurons cultured in neurobasal medium containing no phenol red had large depolarization-associated epileptiform bursting activities, which were rarely seen in neurons cultured in phenol red-containing medium. Further experiment data indicate that the suppressive effect of the phenol red on the abnormal epileptiform burst neuronal activities was U-shape dose related, with the most effective concentration at 28 µM. In addition, this concentration related inhibitory effect of phenol red on the epileptiform neuronal discharges was mimicked by 17-ß-estradiol, an estrogen receptor agonist, and inhibited by ICI-182,780, an estrogen receptor antagonist. Our results suggest that estrogen receptor activation by phenol red in the culture medium prevents formation of abnormal, epileptiform burst activity. These studies highlight the importance of phenol red as estrogen receptor stimulator and cautions of careful use of phenol red in cell culture media.