Nacre-inspired cellulose nanofiber/MXene flexible composite film with mechanical robustness for humidity sensing.

Inspired by nacre-layered nanostructure, 1D 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-oxidized cellulose nanofibers (TOCNFs) were used as the template to assemble 2D MXene nanosheets into a layered TOCNF/MXene nanocomposite film by a vacuum-assisted filtration strategy. The synergistic effect of the MXene "brick" and TOCNFs "mortar" endowed the composite film with excellent flexibility and a tensile strength of 128.13 MPa, which were attributed to interactions between the interconnected three-dimensional network and multiple hydrogen bonds between TOCNFs and MXene. The humidity-sensing mechanism of the sensor involved the swelling/contraction of channels between MXene interlayers induced by adsorbed H2O and the swelling of TOCNFs. The TOCNF/MXene sensor showed a maximum response (-ΔI/I0) of 90 % under 97 % RH, outstanding bending and folding durability (up to 50 cycles), and long-term stability. Lastly, the sensor could dynamically monitor human respiration, skin, and fingertip humidity, suggesting its promising applications in smart wearable electronics.

Pre-attentive dysfunction of processing emotional faces in interictal migraine revealed by expression-related visual mismatch negativity.

BACKGROUND: Several investigations have indicated emotional processing impairment in migraineurs, while no report is available considering the automatic processing of emotional information. In this study, we aimed to characterize the pre-attentive processing of facial expressions in migraine sufferers by recording and analyzing expression-related visual mismatch negativity (EMMN). METHODS: Altogether, 30 migraineurs (19 females) during the interictal period and 30 age-matched healthy controls (17 females) were recruited. An expression-related oddball paradigm was used to investigate automatic emotional processing, and a group of schematic emotional faces (neutral, happy, sad) unrelated to the participant's task were employed in the experiment in order to avoid low-level processing. RESULTS: There was no significant difference in behavioral performance (the response accuracy and reaction time) between migraine patients and healthy controls. Nevertheless, the mean EMMN amplitudes within the ranges of 150-250 ms and 250-350 ms were markedly attenuated in patients compared with controls, regardless of happy or sad condition (happy minus neutral or sad minus neutral), and sad EMMN was observed to be larger than happy EMMN only in healthy participants. Moreover, these electrophysiological data directly correlated with frequency and duration of migrainous attacks. CONCLUSIONS: Our findings implied that the pre-attentive dysfunction of processing both happy and sad expressions was demonstrated in interictal migraineurs, without the existence of negative bias (sad superiority) effect. Further studies on the availability of EMMN as an evaluative marker for migraine are warranted.

Contingent negative variation for the periodicity of migraine attacks without aura.

Migraine is a primary neuropsychological disorder, although its etiology and pathogenesis are unknown. It has been reported that using contingent negative variation, the periodicity of migraine attacks is three days in adults. However, there is still a lack of relevant reports about the periodicity of migraine without aura in adults. Therefore, we investigated the changes of contingent negative variation in adults with migraine without aura from three to seven days after migraine attacks in order to provide the basis for exploring the circulation periodicity of migraine without aura. This prospective, observational study involved a group of 34 individuals with migraine without aura, who were screened during the three to seven days after a migraine attack without aura. A healthy group (31 individuals) was used as controls to assess the amplitudes of contingent negative variation and habituation of early contingent negative variation. Indices of the amplitudes included overall contingent negative variation, initial contingent negative variation, terminal contingent negative variation, and postoperative negative contingent variation. Differences between these indicators were analyzed. No significant difference was found between the patient and control groups for either the amplitudes of these measures of contingent negative variation or habituation of the early contingent negative variation for three to seven days after a migraine attack without aura (all P > 0.05). Thus, the study reported here found that the periodicity of migraine attacks without aura in adults is more than three days.

The impact of attack frequency and duration on neurocognitive processing in migraine sufferers: evidence from event-related potentials using a modified oddball paradigm.

BACKGROUND: Several studies have suggested that migraineurs suffer from neurocognitive abnormalities, but this phenomenon and exact mechanisms remain controversial. In this study, we aimed to reevaluate visual spatial attention via event-related potential (ERP) examinations and explore further correlations between ERP data and migraine characteristics. METHODS: Altogether, 25 migraine patients (9 males, 16 females; mean age 35.240 years) in the interictal period and 21 age-matched healthy controls (8 males, 13 females; mean age 35.286 years) were recruited. A modified visual oddball paradigm which contained standard, target and novel stimuli was used in the test, and amplitudes and latencies of corresponding original/difference ERP components were measured and analyzed independently. RESULTS: We found that P3 amplitude was markedly reduced in migraineurs. This phenomenon was further validated in analysis of difference P3 components (target minus standard and novel minus standard). Additionally, the N1 and N2 latencies elicited by novel stimulus were both delayed in patients compared with controls. Furthermore, these deviant cognitive ERPs were correlated with frequency and duration of migraine attacks. CONCLUSIONS: These results indicated impaired visual spatial attention in migraine patients, which could be related to frequency and duration of attacks.

Female versus male migraine: an event-related potential study of visual neurocognitive processing.

BACKGROUND: Several studies have suggested cognitive deficits in migraineurs, and sex differences have also been observed in migraine, such as a higher prevalence in females. Nevertheless, little is known about gender-related differences in cognitive processing. In this study, we aimed to investigate the effect of gender on neurocognitive processing in migraineurs. METHODS: Altogether, 46 migraine patients without aura (23 females; mean age 32.848 years) during the interictal period and 46 age-matched healthy controls (23 females; mean age 32.652 years) were recruited. The emotional characteristics of participants were evaluated, and attentive processing was analyzed via event-related potential examinations using a three-stimulus visual oddball paradigm. RESULTS: We found that migraineurs suffered from emotional and visual cognitive processing abnormalities compared with healthy controls, including higher levels of anxiety and reduced P3 amplitude. These parameters were modulated by gender in migraine patients, but not in healthy participants. Our findings indicated that female patients seemed to be more anxious and have more severe impairment in attentive processing of visual stimuli than their male counterparts. The gender-related differences in migraineurs were further validated using event-related potential difference waveforms. CONCLUSIONS: These results suggested that migraine might have an additional influence on females and lead to more dysfunction in their interictal neurocognitive processing. Our findings provide evidence that a gender effect exists in migraineurs, which should be considered when designing experiments and exploring treatment approaches. The gender-related differences and underlying mechanisms deserve further investigation for patients with migraine.

Selective attention network impairment during the interictal period of migraine without aura.

Attention deficits have been demonstrated in migraine patients during the interictal period, but these findings are not consistent across all studies. These inconsistencies may arise due to the different aspects of attention measured by various psychometric tests. Current theories divide attention into three separate domains subserved by separate networks: alerting, orienting, and executive control. The attention network test (ANT) was developed to measure all three attention networks and so may reveal more specific attention deficits among migraineurs. The aim of this study was to evaluate the attention function of migraine without aura (MwoA) patients using a series of neuropsychological scales and the ANT, and to assess the relationships between attention function and headache characteristics (e.g., history, frequency, and duration of each attack). Our results showed that MwoA patients exhibited significantly longer response times (RTs) of the executive control network, whereas no significant differences were observed in alerting and orienting network RTs between groups. MwoA patients also exhibited poorer performance than health control (HC) on the Stroop III and Shape Trail test B (STT B) tests. Spearman's analysis revealed positive correlations between executive control network RTs and both frequency and duration of migraine attack. MwoA patients demonstrate impairments of the executive control network, which appear to be exacerbated by more frequent and longer migraine attacks.

Cloning, Purification, and Partial Characterization of the Halobacterium sp. NRC-1 Minichromosome Maintenance (MCM) Helicase.

The MCM gene from the archaeon Halobacterium, with and without its intein, was cloned into an Escherichia coli expression vector, overexpressed and the protein was purified and antibodies were generated. The antibodies were used to demonstrate that in vivo only the processed enzyme, without the intein, could be detected.

Coupling of DNA binding and helicase activity is mediated by a conserved loop in the MCM protein.

Minichromosome maintenance (MCM) helicases are the presumptive replicative helicases, thought to separate the two strands of chromosomal DNA during replication. In archaea, the catalytic activity resides within the C-terminal region of the MCM protein. In Methanothermobacter thermautotrophicus the N-terminal portion of the protein was shown to be involved in protein multimerization and binding to single and double stranded DNA. MCM homologues from many archaeal species have highly conserved predicted amino acid similarity in a loop located between beta7 and beta8 in the N-terminal part of the molecule. This high degree of conservation suggests a functional role for the loop. Mutational analysis and biochemical characterization of the conserved residues suggest that the loop participates in communication between the N-terminal portion of the helicase and the C-terminal catalytic domain. Since similar residues are also conserved in the eukaryotic MCM proteins, the data presented here suggest a similar coupling between the N-terminal and catalytic domain of the eukaryotic enzyme.