Task Cortical Connectivity Reveals Different Network Reorganizations between Mild Stroke Patients with Cortical and Subcortical Lesions.

Accumulating efforts have been made to investigate cognitive impairment in stroke patients, but little has been focused on mild stroke. Research on the impact of mild stroke and different lesion locations on cognitive impairment is still limited. To investigate the underlying mechanisms of cognitive dysfunction in mild stroke at different lesion locations, electroencephalograms (EEGs) were recorded in three groups (40 patients with cortical stroke (CS), 40 patients with subcortical stroke (SS), and 40 healthy controls (HC)) during a visual oddball task. Power envelope connectivity (PEC) was constructed based on EEG source signals, followed by graph theory analysis to quantitatively assess functional brain network properties. A classification framework was further applied to explore the feasibility of PEC in the identification of mild stroke. The results showed worse behavioral performance in the patient groups, and PECs with significant differences among three groups showed complex distribution patterns in frequency bands and the cortex. In the delta band, the global efficiency was significantly higher in HC than in CS (p = 0.011), while local efficiency was significantly increased in SS than in CS (p = 0.038). In the beta band, the small-worldness was significantly increased in HC compared to CS (p = 0.004). Moreover, the satisfactory classification results (76.25% in HC vs. CS, and 80.00% in HC vs. SS) validate the potential of PECs as a biomarker in the detection of mild stroke. Our findings offer some new quantitative insights into the complex mechanisms of cognitive impairment in mild stroke at different lesion locations, which may facilitate post-stroke cognitive rehabilitation.

Sleep patterns correlates with the efficacy of tDCS on post-stroke patients with prolonged disorders of consciousness.

BACKGROUND: The subclassification of prolonged disorders of consciousness (DoC) based on sleep patterns is important for the evaluation and treatment of the disease. This study evaluates the correlation between polysomnographic patterns and the efficacy of transcranial direct current stimulation (tDCS) in patients with prolonged DoC due to stroke. METHODS: In total, 33 patients in the vegetative state (VS) with sleep cycles or without sleep cycles were randomly assigned to either active or sham tDCS groups. Polysomnography was used to monitor sleep changes before and after intervention. Additionally, clinical scale scores and electroencephalogram (EEG) analysis were performed before and after intervention to evaluate the efficacy of tDCS on the patients subclassified according to their sleep patterns. RESULTS: The results suggest that tDCS improved the sleep structure, significantly prolonged total sleep time (TST) (95%CI: 14.387-283.527, P = 0.013) and NREM sleep stage 2 (95%CI: 3.157-246.165, P = 0.040) of the VS patients with sleep cycles. It also significantly enhanced brain function of patients with sleep cycles, which were reflected by the increased clinical scores (95%CI: 0.340-3.440, P < 0.001), the EEG powers and functional connectivity in the brain and the 6-month prognosis. Moreover, the changes in NREM sleep stage 2 had a significant positive correlation with each index of the ß band. CONCLUSION: This study reveals the importance of sleep patterns in the prognosis and treatment of prolonged DoC and provides new evidence for the efficacy of tDCS in post-stroke patients with VS patients subclassified by sleep pattern. Trial registration URL: https://www. CLINICALTRIALS: gov . Unique identifier: NCT03809936. Registered 18 January 2019.

Dynamic Reorganization of Functional Connectivity During Post-Break Task Reengagement.

Because of the undesired fatigue-related consequences, accumulating efforts have been made to find an effective intervention to alleviate the suboptimal cognitive function caused by mental fatigue. Nonetheless, limitations of intervention and evaluation methods may hinder the revealing of underlying neural mechanisms of fatigue recovery. Through the newly-developed dynamic functional connectivity (FC) analysis framework, this study aims to investigate the effects of two types of mid-task interventions (i.e., rest-break and moderate-intensity exercise-break) on the dynamic reorganization of FC during the execution of psychomotor vigilance test (PVT). Using a sliding window approach, temporal brain networks within each frequency band (i.e., δ , θ , α , & ß ) were estimated before and immediately after the intervention, and towards the end of the task to investigate the immediate and delayed effects respectively during post-break task reengagement. Behaviourally, similar beneficial effects of exercise- and rest-break on performance were observed, manifested by the immediate improvements after both interventions and a long-lasting influence towards the end of tasks. Moreover, temporal brain networks assessment showed significant immediate decreases of fluctuability, which was followed by an increase of fluctuability towards the end of intervention tasks. Furthermore, the temporal nodal measure revealed the channels with significant differences across tasks were mainly resided in the fronto-parietal areas that exhibited interesting frequency-dependent distribution. The observations of immediate and delayed dynamic FC reorganizations extend previous fatigue-related intervention and static FC studies, and provide new insight into the dynamic characteristics of FC during post-break task reengagement.

Photo-Detachable Self-Cleaning Surfaces Inspired by Gecko Toepads.

Strong, reversible, and self-cleaning adhesion in the toe pads of geckos allow the lizards to climb on a variety of vertical and inverted surfaces, regardless of the surface conditions, whether hydrophobic or hydrophilic, smooth or tough, wet or dry, clean or dirty. Development of synthetic gecko-inspired surfaces has drawn a great attention over the past two decades. Despite many external-stimuli responsive mechanisms (i.e., thermal, electrical, magnetic) have been successfully demonstrated, smart adhesives controlled by light signals still substantially lag behind. Here, in this report, we integrate tetramethylpiperidinyloxyl (TEMPO)-doped polydopamine (PDA), namely, TDPDA, with PDMS micropillars using a template-assisted casting method, to achieve both improved adhesion and self-cleaning performances. To the best of our knowledge, this is the first report on PDA being used as a doping nanoparticle in bioinspired adhesive surfaces to achieve highly efficient self-cleaning controllable by light signals. Notably, the adhesion of the 5% TDPDA-PDMS sample is ∼688.75% higher than that of the pure PDMS at the individual pillar level, which helps to explain the highly efficient self-cleaning mechanism. The sample surfaces (named TDPDA-PDMS) can efficiently absorb 808 nm wavelength of light and heat up from 25 °C to 80.9 °C in 3 min with NIR irradiation. The temperature rise causes significant reduction of adhesion, which results in outstanding self-cleaning rate of up to 55.8% within five steps. The exploration of the photoenabled switching mechanism with outstanding sensitivity may bring the biomimetic smart surfaces into a new dimension, rendering varied applications, e.g., in miniaturized climbing robot, artificial intelligence programmable manipulation/assembly/filtration, active self-cleaning solar panels, including high output sensors and devices in many engineering and biomedical frontiers.

[Relationship between sleep architecture and severity of obstructive sleep apnea].

OBJECTIVE: To investigate the effect of obstructive sleep apnea (OSA) on different sleep stages, and the relationship between N3 stage of non-rapid eye movement sleep and respiratory abnormal events. METHODS: A total of 188 adult patients who underwent overnight polysomnography(PSG)monitoring in Sir Run Run shaw Hospital of Zhejiang University from June 24th to December 26th 2019 were enrolled in the study. OSA patients were classified into 3 groups (mild, moderate and severe) according to the apnea-hypopnea index (AHI). PSG data, AHI and the lowest SPO2 in each stage of sleep were compared among three groups. RESULTS: There was no significant difference in total sleep time and sleep efficiency among patients with different severity of OSA (all P>0.05). The proportion of N3 stage in moderate and severe OSA groups were significantly smaller than that in mild OSA group (all P<0.05). The proportion of N3 stage in severe OSA group was also smaller than that in moderate OSA group (P<0.05). In addition, severe OSA group had a longer latency of N3 stage than mild and moderate OSA groups (all P<0.05). The latency of N3 stage in moderate OSA group was longer than that in mild OSA group (P<0.05). The AHI in N3 stage was markedly lower than that in other sleep stages (all P<0.01), regardless of the severity of OSA. Supine AHI in N3 stage in mild and moderate groups was significantly lower than that in N1, N2 and rapid eye movement (REM) stages (all P<0.01). Supine AHI in N3 stage in severe group was also lower than that in N2 and REM stages (P<0.05 or P<0.01). The lowest SPO2 in N3 stage was significantly higher than that in N1, N2 and REM stages (P<0.05 or P<0.01), regardless of the severity of OSA. CONCLUSIONS: s The proportion of N3 stage is lower in OSA patients, and N3 stage has less sleep respiratory events than non-N3 stages. The results suggest that the increased N3 stage proportion may indicate less severity of OSA.

[Effects of resveratrol on aging of mesenchymal stem cells and its mechanism].

OBJECTIVE: To investigate the effects of resveratrol (Res) on aging of marrow mesenchymal stem cells (MSCs), and to explore its mechanism. METHODS: MSCs were isolated from young SD rats and cultured in vitro. The optimal D-gal concentration for induction of MSCs senescence was determined. Then MSCs were randomly divided into four groups, namely the control group, 10µmol/L, 50µmol/L and 100µmol/L Res groups. After the cells were treated with different concentration of Res for 48 h, the senescence-associated changes were examined with senescence-associated-ß-galactosidase (SA-ß-gal) staining; the expression of p53, p16 and γ-H2AX was evaluated by Western blot. The total active oxygen species (ROS) level was determined by flow cytometry with DCFH-DA staining. In order to assess the effect of Res on the mitochondrial function, MitoSox Red staining was used to detect mitochondrial ROS levels in each group, mitochondrial membrane potential was detected by JC-1 assay, mPTP method was used to detect mitochondrial membrane channel opening level, and Western blot was used to detect the expression level of cytoplasmic cytochrome C (Cyt-C). RESULTS: D-gal 10 and 50 g/L significantly increased the number of SA-ß-gal positive cells and the level of mitochondrial ROS (all P<0.01). Therefore, 10 g/L D-gal was used to induce the senescence of MSCs in subsequent experiment. Compared with the control group, the number of SA-ß-gal positive cells in Res groups significantly decreased (all P<0.01), the expression of p53, p16 and γ-H2AX decreased, and the total and mitochondrial ROS level also decreased (all P<0.01). Moreover, mitochondrial membrane potential, open level of mitochondrial membrane channels and the levels of cytoplasm Cyt-C in the Res treatment groups decreased compared with the control group (P<0.05 or P<0.01). CONCLUSIONS: Resveratrol can protect the mitochondrial function of MSCs, and effectively delay the MSC senescence.

The Effect of Romantic Relationships on the Evaluation of the Attractiveness of One's Own Face.

The present study sought to explore the effect of romantic relationships on the attractiveness evaluation of one's own face using two experiments with the probability evaluation and the subjective rating method. Experiment 1 and Experiment 2 enrolled couples and single individuals as participants, respectively. The results of the two experiments indicated that the participants evaluated their own face as significantly more attractive than did others of the same sex. More importantly, the romantic relationship enhanced the positive bias in the evaluation of self-face attractiveness, that is, couple participants showed a stronger positive bias than did single individuals. It was also found that a person in a romantic relationship was prone to overestimating the attractiveness of his or her lover's face, from the perspective of both probability evaluation and rating score. However, the abovementioned overestimation did not surpass the evaluations of the exaggeratedly attractive face. The present results supported the observer hypothesis, demonstrating the romantic relationship to be an important influential factor of facial attractiveness. Our findings have important implications for the research of self-face evaluation.