A sleepless night disrupts the resolution of emotional conflicts: Behavioural and neural evidence.

The present study aims to investigate the influence of 24-hr sleep deprivation on implicit emotion regulation using the emotional conflict task. Twenty-five healthy young adults completed a repeated-measures study protocol involving a night of at-home normal sleep control and a night of in-laboratory sleep deprivation. Prior to the experimental session, all participants wore an actigraph watch and completed the sleep diary. Following each condition, participants performed an emotional conflict task with electroencephalographic recordings. Emotional faces (fearful or happy) overlaid with words ("fear" or "happy") were used as stimuli creating congruent or incongruent trials, and participants were instructed to indicate whether the facial expression was happy or fearful. We measured the accuracy and reaction time on the emotional conflict task, as well as the mean amplitude of the P300 component of the event-related potential at CPz. At the behavioural level, sleep-deprived participants showed reduced alertness with overall longer reaction times and higher error rates. In addition, participants in the sleep deprivation condition made more errors when the current trial followed congruent trials compared with when it followed incongruent trials. At the neural level, P300 amplitude evoked under the sleep-deprived condition was significantly more positive compared with the normal sleep condition, and this effect interacted with previous-trial and current-trial congruency conditions, suggesting that participants used more attentional resources to resolve emotional conflicts when sleep deprived. Our study provided pioneering data demonstrating that sleep deprivation may impair the regulation of emotional processing in the absence of explicit instruction among emerging adults.

A longitudinal examination of the measurement properties and invariance of the Sleep Condition Indicator in Chinese healthcare students.

BACKGROUND: The Sleep Condition Indicator (SCI), an insomnia measurement tool based on the updated Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria with sound psychometric properties when applied in various populations, was evaluated here among healthcare students longitudinally, to demonstrate its measurement properties and invariance in this particularly high-risk population. METHODS: Healthcare students of a Chinese university were recruited into this two-wave longitudinal study, completing the simplified Chinese version of the SCI (SCI-SC), Chinese Regularity, Satisfaction, Alertness, Timing, Efficiency, Duration (RU_SATED-C) scale, Chinese Patient Health Questionnaire-4 (PHQ-4-C), and sociodemographic variables questionnaire (Q-SV) between September and November 2022. Structural validity, measurement invariance (MI), convergent and discriminant validity, internal consistency, and test-retest reliability of the SCI-SC were examined. Subgroups of gender, age, home location, part-time job, physical exercise, and stress-coping strategy were surveyed twice to test cross-sectional and longitudinal MI. RESULTS: We identified 343 valid responses (62.9% female, mean age = 19.650 ± 1.414 years) with a time interval of seven days. The two-factor structure was considered satisfactory (comparative fit index = 0.953-0.989, Tucker-Lewis index = 0.931-0.984, root means square error of approximation = 0.040-0.092, standardized root mean square residual = 0.039-0.054), which mostly endorsed strict invariance except for part-time job subgroups, hence establishing longitudinal invariance. The SCI-SC presented acceptable convergent validity with the RU_SATED-C scale (r ≥ 0.500), discriminant validity with the PHQ-4-C (0.300 ≤ r < 0.500), internal consistency (Cronbach's alpha = 0.811-0.835, McDonald's omega = 0.805-0.832), and test-retest reliability (intraclass correlation coefficient = 0.829). CONCLUSION: The SCI-SC is an appropriate screening instrument available for assessing insomnia symptoms among healthcare students, and the promising measurement properties provide additional evidence about validity and reliability for detecting insomnia in healthcare students.

Stroke caregivers' perception on instant messaging application use for psychological intervention: a qualitative study.

In caring for patients with stroke, the leading cause of death and disability affecting over 80 million people worldwide, caregivers experience substantial psychological and physical burdens and difficulties in help-seeking owing to physical and time-constraints. Social distancing measures imposed during the coronavirus disease 2019 (COVID-19) pandemic further restricted them from using caregiver support services. While the use of telehealth emerged as a global prevailing trend during the COVID-19 pandemic, evidence for utilising instant messaging (IM) applications for psychological intervention is scanty. This study aimed to explore stroke caregivers' perceived potential utility of IM-delivered psychological intervention. Between January and August 2020, 36 adult family stroke caregivers in Hong Kong were recruited to individual telephone semi-structured interviews using purposive sampling. The interviews were audio-recorded, transcribed verbatim and analysed using an interpretive description approach. Three themes of caregivers' perceptions towards IM-delivered psychological intervention emerged: perceived high convenience and ease of use, perceived advantages that overcome existing barriers to services and message delivery tailored to individual needs. Our findings suggested that there is an imminent need among stroke caregivers for personalised psychological interventions and that IM is a potential modality for overcoming existing barriers in delivering accessible support to caregivers in real-time, real-world settings. Our study highlighted caregivers' acceptance and perceived benefits of IM-delivered psychological intervention and provided practical insights into the design of IM-delivered psychological interventions.

Proteomic analysis of zebrafish folliculogenesis identifies YB-1 (Ybx1/ybx1) as a potential gatekeeping molecule controlling early ovarian folliculogenesis.

As in mammals, ovarian folliculogenesis in teleosts also consists of two phases: the primary growth (PG) and secondary growth (SG) phases, which are analogous to the preantral and antral phases respectively in mammals. In this study, we performed a proteomic analysis on zebrafish follicles undergoing the PG-SG transition aiming to identify factors involved in the event. Numerous proteins showed significant changes, and the most prominent one was Y-box binding protein 1 (YB-1; Ybx1/ybx1), a transcription factor and mRNA-binding protein. YB-1 belongs to the Y-box binding protein family, which also includes the gonad-specific YB-2. Interestingly, phylogenetic analysis showed no YB-2 homolog in zebrafish. Although ybx1 mRNA was expressed in various tissues, its protein Ybx1 was primarily produced in the gonads, similar to YB-2 in other species. In the ovary, Ybx1 protein started to appear in early follicles newly emerged from the germ cell cysts, reached the highest level in late PG oocytes, but decreased precipitously when the follicles entered the SG phase. In PG follicles, Ybx1 might function as a key component of the messenger ribonucleoprotein particles (mRNPs) in association with other RNA-binding proteins. Similar to mammalian YB-1, zebrafish Ybx1 also contains functional signals that determine its intracellular localization. In conclusion, Ybx1 may play dual roles of YB-1 and YB-2 in zebrafish. In the ovary, Ybx1 binds mRNAs to stabilize them while preventing their translation. At PG-SG transition, Ybx1 is removed to release the masked mRNAs for translation into functional proteins, leading to follicle activation.

Identifying multilevel predictors of trajectories of psychopathology and resilience among juvenile offenders: A machine learning approach.

Mental ill health is more common among juvenile offenders relative to adolescents in general. Little is known about individual differences in their long-term psychological adaptation and its predictors from multiple aspects of their life. This study aims to identify heterogeneous trajectories of probable psychiatric conditions and their predictors. Participants included 574 juvenile offenders who were first convicted for serious crimes and without detention history. The participants were assessed at 11 timepoints over seven years (2000-2010). Growth mixture modeling revealed the same three trajectories for both probable anxiety and probable depression: stable low trajectory (75.96%; 75.78%), stable high trajectory (15.16%; 10.98%), and recovery (8.89%, 13.24%). Least absolute shrinkage and selection operator (LASSO) logistic regression identified three multilevel predictors for memberships of different trajectories. Risk factors against stable low trajectory lay within personal (e.g., neuroticism), relationship (e.g., parental hostility), and contextual levels (e.g., chaotic neighborhood). Resilience factors for stable low trajectory included strong work orientation and low education level of father. Recovery was predicted by Black race, self-identity, high education level of father, and nonincarcerated sentencing. Our findings suggest that both psychopathology and psychological resilience could be predicted by multiple personal, relationship, and contextual factors in the social ecology of juvenile offenders.

Sleep and Inhibitory Control Over Mood-Congruent Information in Emerging Adults With Depressive Disorder.

OBJECTIVE: Accumulating evidence has suggested bidirectionality between sleep problems and depression, but the underlying mechanism is unclear. We assessed the role of sleep in inhibitory control ability with emotional stimuli, which has been shown to be suboptimal among individuals with depression and proposed to perpetuate depressive symptoms. METHODS: Emerging adults (aged 18-25 years, 64.6% female) were screened for depressive and other mental disorders by structured clinical interview and questionnaire. Individuals with depressive disorders were assigned to have a polysomnography-monitored daytime sleep opportunity (Sleep-Dep, n = 20), whereas nondepressed individuals were randomized to either have daytime sleep (Sleep-Ctrl, n = 27) or stay awake (Wake-Ctrl, n = 18). Participants completed the Affective Go/No-Go Task two times, separated by experimental conditions. RESULTS: A factorial model with a between-subject factor (Sleep-Dep/Sleep-Ctrl/Wake-Ctrl) and a within-subject factor (test 1/test 2) was used to assess if the groups differed in inhibitory control across test sessions, as inferred by changes in d-prime and false alarm rates (FA). Results from mixed factorial models showed a significant interaction effect between time and group on FA in the block with neutral faces as the target and happy faces as the nontarget (F(2,61) = 5.15, pfdr = .045). Although Sleep-Dep had decreased FA after sleep (t(19) = 2.94, pfdr = .050), Sleep-Ctrl and Wake-Ctrl had no significant between-session changes (p values > .05). Postsleep improvement in FA in Sleep-Dep correlated with longer stage 2 sleep (r(20) = 0.788, pfdr < .001) and stage 2 fast spindle number at O1 (r(18) = 0.692, pfdr = .015). CONCLUSIONS: Sleep gain, particularly stage 2 sleep and related physiology, potentially enhances inhibitory control ability responding to emotional information among individuals with depressive disorders.

Sleep differentially impacts involuntary intrusions and voluntary recognitions of lab-analogue traumatic memories.

Despite the critical role of sleep in memory and emotion processing, large remains unknown regarding how sleep influences trauma-related symptoms arising from maladaptive memory/emotional processes, such as those among patients with post-traumatic stress disorder. Employing a trauma film paradigm, we investigated how post-trauma sleep versus sleep deprivation influenced involuntary intrusions and voluntary recognition of traumatic memories. Sixty participants were randomly assigned to sleep or total sleep deprivation group following experimental trauma induction. Participants were assessed with: (a) lab-based and 7-day diary-based involuntary intrusions; (b) voluntary recognitions of traumatic memories 12-hr and 7-day post-trauma induction; and (c) post-traumatic stress disorder-like symptoms measured by the Impact of Event Scale-Revised. We found that compared with sleep deprivation, slept participants experienced fewer traumatic intrusions across 7 days, reported lower emotional hyperarousal, and showed more accurate recognition of trauma-related stimuli. Moreover, higher subjective sleep quality was associated with fewer intrusions only in the sleep group, while a reversed pattern emerged in the sleep deprivation group. These results provide novel evidence supporting the therapeutic benefits of sleep in protecting mental well-being from trauma exposure. To the extent that sleep modulates trauma-related symptoms, sleep can be conceived as the potential target for early interventions among trauma victims.

Noise sensitivity associated with nonrestorative sleep in Chinese adults: a cross-sectional study.

BACKGROUND: Nonrestorative sleep is a common sleep disorder with a prevalence ranging from 1.4 to 35%, and is associated with various psychological and physical health issues. Noise exposure and noise sensitivity have been proposed to contribute to nonrestorative sleep. This study aimed to examine the relationships among noise, noise sensitivity, nonrestorative sleep, and physiological sleep parameters in Chinese adults. METHODS: A cross-sectional household survey was conducted with randomly selected Chinese adults based on a frame stratified by geographical districts and types of quarters in Hong Kong. We administered a battery of questionnaires, including the Nonrestorative Sleep Scale, the Weinstein Noise Sensitivity Scale, the ENRICHD Social Support Instrument, the Patient Health Questionnaire, and the Perceived Stress Scale to assess nonrestorative sleep, noise sensitivity, social support, somatic symptoms and stress, respectively. Anxiety and depression were evaluated by the Hospital Anxiety and Depression Scale while sociodemographic and lifestyle characteristics were assessed with an investigator-developed sheet. Nocturnal noise level and physiological sleep parameters were measured during nighttime for a week by noise dosimetry and actigraphy, respectively. A structured multiphase linear regression was conducted to estimate associations. RESULTS: A total of 500 adults (66.4% female) with an average age of 39 years completed this study. Bivariate regressions showed that age, marital status, occupation, family income, season, exercise, cola and soda consumption, social support, somatic symptoms, stress, depression, noise sensitivity, total sleep time, and awakenings were associated with nonrestorative sleep. In the multivariable analysis, family income, season, exercise, social support, somatic symptoms, stress, and depression remained associated with nonrestorative sleep. Specifically, a one-unit increase of noise sensitivity was associated with 0.08 increase in nonrestorative sleep (95% confidence interval [CI]: 0.01, 0.15, p = 0.023). Nocturnal noise was negatively associated with time in bed (b = - 1.65, 95% CI: - 2.77, - 0.52, p = 0.004), total sleep time (b = - 1.61, 95% CI: - 2.59, - 0.62, p = 0.001), and awakenings (b = - 0.16, 95% CI: - 0.30, - 0.03, p = 0.018), but was not associated with nonrestorative sleep. CONCLUSIONS: Nonrestorative sleep was predicted by noise sensitivity in addition to family income, season, exercise, social support, somatic symptoms, stress, and depression.

Indoor nocturnal noise is associated with body mass index and blood pressure: a cross-sectional study.

BACKGROUND: Studies have demonstrated that noise is associated with various health problems, such as obesity and hypertension. Although the evidence of the associations of noise with obesity and hypertension is inconsistent, there seems to be a stronger association of the latter. This study aimed to investigate the associations of noise with body mass index (BMI) and blood pressure in adults living in multi-story residential buildings. METHODS: A cross-sectional study was conducted in Hong Kong from February 2018 to September 2019. The Weinstein Noise Sensitivity Scale, Pittsburgh Sleep Quality Index, ENRICHD Social Support Instrument, Patient Health Questionnaire, Perceived Stress Scale, and Hospital Anxiety and Depression Scale were administered to the participants. BMI and blood pressure were assessed. Nocturnal noise exposure and total sleep duration were measured for a week. RESULTS: Five hundred adults (66.4% female), with an average age of 39 years (range: 18-80), completed the study. The average levels of nocturnal noise, BMI, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 51.3 dBA, 22.2 kg/m2, 116.0 mmHg, and 75.4 mmHg, respectively. After adjusting for sociodemographic characteristics, nocturnal noise was associated with BMI (b = 0.54, 95% CI: 0.01 to 1.06, p = 0.045) and SBP (b = 2.90, 95% CI: 1.12 to 4.68, p = 0.001). No association was detected between nocturnal noise and DBP (b = 0.79, 95% CI: - 0.56 to 2.13, p = 0.253). Specifically, higher nocturnal noise was associated with higher BMI (b = 0.72, 95% CI: 0.07 to 1.38, p = 0.031) and SBP (b = 3.91, 95% CI: 2.51 to 5.31, p < 0.001) in females but only higher SBP (b = 3.13, 95% CI: 1.35 to 4.92, p < 0.001) in males. The association between noise and SBP remained significant (b = 2.41, 95% CI: 0.62 to 4.20, p = 0.008) after additionally adjusting for lifestyle, diagnosis of hypertension, psychometric constructs, and sleep. CONCLUSIONS: Indoor nocturnal noise was associated with BMI and blood pressure in females but only blood pressure in males. It is important to control nocturnal noise or use soundproofing materials in buildings to reduce noise exposure.

Functional genomic characterization of a synthetic anti-HER3 antibody reveals a role for ubiquitination by RNF41 in the anti-proliferative response.

Dysregulation of the ErbB family of receptor tyrosine kinases is involved in the progression of many cancers. Antibodies targeting the dimerization domains of family members EGFR and HER2 are approved cancer therapeutics, but efficacy is restricted to a subset of tumors and resistance often develops in response to treatment. A third family member, HER3, heterodimerizes with both EGFR and HER2 and has also been implicated in cancer. Consequently, there is strong interest in developing antibodies that target HER3, but to date, no therapeutics have been approved. To aid the development of anti-HER3 antibodies as cancer therapeutics, we combined antibody engineering and functional genomics screens to identify putative mechanisms of resistance or synthetic lethality with antibody-mediated anti-proliferative effects. We developed a synthetic antibody called IgG 95, which binds to HER3 and promotes ubiquitination, internalization, and receptor down-regulation. Using an shRNA library targeting enzymes in the ubiquitin proteasome system, we screened for genes that effect response to IgG 95 and uncovered the E3 ubiquitin ligase RNF41 as a driver of IgG 95 anti-proliferative activity. RNF41 has been shown previously to regulate HER3 levels under normal conditions and we now show that it is also responsible for down-regulation of HER3 upon treatment with IgG 95. Moreover, our findings suggest that down-regulation of RNF41 itself may be a mechanism for acquired resistance to treatment with IgG 95 and perhaps other anti-HER3 antibodies. Our work deepens our understanding of HER3 signaling by uncovering the mechanistic basis for the anti-proliferative effects of potential anti-HER3 antibody therapeutics.

Impact of robotic assistance on mental workload and cognitive performance of surgical trainees performing a complex minimally invasive suturing task.

BACKGROUND: Few studies have investigated the potential impact of robotic assistance on cognitive ergonomics during advanced minimally invasive surgery. The purpose of this study was to assess the impact of robotic assistance on mental workload and downstream cognitive performance in surgical trainees. METHODS: Robot-naïve trainees from general surgery, urology and gynaecology, stratified by specialty and level of training, were randomised to either laparoscopic surgery (LS) or robotic-assisted laparoscopic surgery (RALS) and performed a time-limited, complex laparoscopic suturing task after watching a 5-min instructional video. The RALS group received an additional 5-min orientation to the robotic console. Subjective mental workload was measured using NASA Task Load Index. Concentration and executive cognitive function were assessed using Psychomotor Vigilance Task (PVT) and Wisconsin Card Sorting Test (WCST), respectively. A p value of 0.05 was considered significant. RESULTS: Sixteen senior residents (SR; ≥ PGY3) and 14 junior residents (JR; PGY1-2) completed the study. There was no difference in mental workload between LS and RALS. Within JR there was no difference in task completion time comparing LS versus RALS; however, LS was associated with impaired concentration post-task versus pre-task (PVT reaction time 306 versus 324 ms, p = 0.03), which was not observed for RALS. In contrast, amongst SR, RALS took significantly longer than LS (10.3 vs. 14.5 min, p = 0.02) and was associated with significantly worse performance on WCST (p < 0.01). CONCLUSIONS: Robotic assistance, in this setting, did not provide a technical performance advantage nor impact subjective mental workload with novice users regardless of level of surgery training. We observed a protective effect on cognitive performance offered by RALS to junior trainees with limited LS experience, yet a detrimental effect on senior trainees with greater LS ability and inadequate pre-study robotic training, suggesting that robotic consoles may be mentally taxing for robotic novices and consideration should be given to formal console training prior to initial clinical exposure.

Factors affecting Australian aged care facility workers in administering oral medication to residents with swallowing difficulties.

Swallowing difficulties are common in older people and can complicate the administration of oral medications. The aim of this study was to explore factors affecting healthcare workers in their practices of oral medication administration to aged care residents with swallowing difficulties. A purposeful sample of 17 healthcare workers composed of clinical/care managers, registered nurses (RNs), enrolled nurses (ENs), and assistants in nursing (AINs) from three aged care facilities in Queensland, Australia participated in semi-structured interviews. Leximancer was used for quantitative content analysis. The responses centered on three main factors. Participants discussed workprocess-related factors including time, workload, and stress and frustrations resulting from work processes. Medication-related factors included strategies to facilitate medication administration, uncertainties around modifying medications, availability/cost of alternatives, multidisciplinary medication management, prescribing considerations, and polypharmacy. Resident-related factors were discussed around individualized needs of residents especially those with dementia-associated swallowing difficulties. Ideas differed among the four groups of participants. Managers discussed workprocess-related factors pertaining to staff and facility. RNs focused on how clinical aspects of the medication practices were affected by work processes. ENs were task-oriented and their responses focused on work processes. AIN responses centered on reliance on RNs in performing medication tasks. The findings suggest that healthcare workers' practices of medication administration to residents with swallowing difficulties are affected by various factors associated with work processes, medications, and resident characteristics. Although these factors affect all levels of healthcare workers, the needs of each group vary depending on their level of training and responsibilities.

Using emotion regulation strategies after sleep deprivation: ERP and behavioral findings.

Sleep deprivation is suggested to impact emotion regulation, but few studies have directly examined it. This study investigated the influence of sleep deprivation on three commonly used emotion regulation strategies (distraction, reappraisal, suppression) in Gross's (1998) process model of emotion regulation. Young healthy adults were randomly assigned to a sleep deprivation group (SD; n = 26, 13 males, age = 20.0 ± 1.7) or a sleep control group (SC; n = 25, 13 males, age = 20.2 ± 1.7). Following 24-h sleep deprivation or normal nighttime sleep, participants completed an emotion regulation task, in which they naturally viewed or applied a given emotion regulation strategy towards negative pictures, with electroencephalographic (EEG) recordings. A reduction in the centroparietal late positive potential (LPP) amplitudes towards negative pictures from the naturally viewing condition to a regulated condition was calculated as an index of regulatory effects. Comparisons between the two groups indicated that sleep deprivation significantly impaired the regulatory effects of distraction and reappraisal on LPP amplitudes. Suppression did not reduce LPP amplitudes in either group. In addition, habitual sleep quality moderated the effect of sleep deprivation on subjective perception of emotional stimuli, such that sleep deprivation only made good sleepers perceive negative pictures as more unpleasant and more arousing, but it had no significant effect on poor sleepers' perception of negative pictures. Altogether, this study provides the first evidence that sleep deprivation may impair the effectiveness of applying adaptive emotion regulation strategies (distraction and reappraisal), creating potentially undesirable consequences to emotional well-being.

Sleep deprivation compromises resting-state emotional regulatory processes: An EEG study.

Resting-state spontaneous neural activities consume far more biological energy than stimulus-induced activities, suggesting their significance. However, existing studies of sleep loss and emotional functioning have focused on how sleep deprivation modulates stimulus-induced emotional neural activities. The current study aimed to investigate the impacts of sleep deprivation on the brain network of emotional functioning using electroencephalogram during a resting state. Two established resting-state electroencephalogram indexes (i.e. frontal alpha asymmetry and frontal theta/beta ratio) were used to reflect the functioning of the emotion regulatory neural network. Participants completed an 8-min resting-state electroencephalogram recording after a well-rested night or 24 hr sleep deprivation. The Sleep Deprivation group had a heightened ratio of the power density in theta band to beta band (theta/beta ratio) in the frontal area than the Sleep Control group, suggesting an affective approach with reduced frontal cortical regulation of subcortical drive after sleep deprivation. There was also marginally more left-lateralized frontal alpha power (left frontal alpha asymmetry) in the Sleep Deprivation group compared with the Sleep Control group. Besides, higher theta/beta ratio and more left alpha lateralization were correlated with higher sleepiness and lower vigilance. The results converged in suggesting compromised emotional regulatory processes during resting state after sleep deprivation. Our work provided the first resting-state neural evidence for compromised emotional functioning after sleep loss, highlighting the significance of examining resting-state neural activities within the affective brain network as a default functional mode in investigating the sleep-emotion relationship.

Baltic amber teething necklaces: could succinic acid leaching from beads provide anti-inflammatory effects?

BACKGROUND: Baltic amber teething necklaces have been popularized as a safe and natural alternative to conventional or pharmacological medicines for the management of teething pain. However, claims made by retailers regarding the efficacy and mechanism of action of these necklaces lack scientific or clinical basis. The claim most closely resembling science is the assertion that succinic acid will leach out of the beads and through the skin of the wearer and carry out anti-inflammatory and analgesic effects. The objective of the current research is to scientifically assess this claim. METHODS: Beads from necklaces were powdered for identification by infrared spectroscopy, and dissolved in sulfuric acid for quantification of succinic acid using HPLC. Succinic acid release from beads was assessed by long-term submersion of amber beads (separated according to light, medium and dark brown colour) in solvents relevant to human skin conditions. The potential for succinic acid to have anti-inflammatory effects was assessed by measuring the release of inflammatory cytokines IL-1α, IL-1ß, IL-8 and TNFα, and the inflammatory messenger PGE2, from THP-1 human macrophages after treatment with succinic acid and LPS. RESULTS: Amber teething necklaces were positively identified as Baltic amber, by comparison of the beads' infrared spectrum to the literature, and by their succinic acid content (1.5 mg per bead; 1.44% w/w). However, whole amber beads submerged in octanol or pH 5.5 phosphate buffered saline did not release any measurable succinic acid, except for the light-coloured beads in octanol which broke into tiny fragments. Additionally, treatment of macrophages with succinic acid did not reduce the release of any inflammatory cytokines measured, and displayed toxicity to the cells at high concentrations. CONCLUSIONS: While amber teething necklaces are genuine Baltic amber, we have found no evidence to suggest that the purported active ingredient succinic acid could be released from the beads into human skin. Additionally, we found no evidence to suggest that succinic acid has anti-inflammatory properties.

Beneficial effects of a daytime nap on verbal memory in adolescents.

This study aimed to examine the sleep-dependent memory consolidation of verbal declarative memory in Chinese adolescents in a naturalistic experimental setting. Thirty-nine healthy boarding school students (ages 15-18, 70% female) were randomized to either a one-hour afternoon nap or wake group between the baseline and the retest sessions of three verbal declarative memory tasks: a Prose Stories Recall task, a Word Pair Associates task, and Rey Auditory Verbal Learning Test. Results showed that the nap group performed better than the no-nap group on both the Prose Stories Recall task and the Word Pair Associates task, but not on list learning. Our findings suggest that napping is beneficial to verbal declarative memory in adolescents, providing ecologically-valid empirical support for the sleep-dependent memory consolidation hypothesis using a napping paradigm in participants' naturalistic habitat. Our results demonstrate the potential importance of napping as a practical mnemonic intervention/compensatory strategy for student populations.