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Frontiers in Human Neuroscience 2022Neurofeedback has been suggested as a potential complementary therapy to different psychiatric disorders. Of interest for this approach is the prediction of individual...
Neurofeedback has been suggested as a potential complementary therapy to different psychiatric disorders. Of interest for this approach is the prediction of individual performance and outcomes. In this study, we applied functional connectivity-based modeling using electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) modalities to (i) investigate whether resting-state connectivity predicts performance during an affective neurofeedback task and (ii) evaluate the extent to which predictive connectivity profiles are correlated across EEG and fNIRS techniques. The fNIRS oxyhemoglobin and deoxyhemoglobin concentrations and the EEG beta and gamma bands modulated by the alpha frequency band (beta--alpha and gamma--alpha, respectively) recorded over the frontal cortex of healthy subjects were used to estimate functional connectivity from each neuroimaging modality. For each connectivity matrix, relevant edges were selected in a leave-one-subject-out procedure, summed into "connectivity summary scores" (CSS), and submitted as inputs to a support vector regressor (SVR). Then, the performance of the left-out-subject was predicted using the trained SVR model. Linear relationships between the CSS across both modalities were evaluated using Pearson's correlation. The predictive model showed a mean absolute error smaller than 20%, and the fNIRS oxyhemoglobin CSS was significantly correlated with the EEG gamma--alpha CSS ( = -0.456, = 0.030). These results support that pre-task electrophysiological and hemodynamic resting-state connectivity are potential predictors of neurofeedback performance and are meaningfully coupled. This investigation motivates the use of joint EEG-fNIRS connectivity as outcome predictors, as well as a tool for functional connectivity coupling investigation.
PubMed: 36158618
DOI: 10.3389/fnhum.2022.977776 -
Nature May 2024Compared to polycrystalline semiconductors, amorphous semiconductors offer inherent cost-effective, simple and uniform manufacturing. Traditional amorphous hydrogenated...
Compared to polycrystalline semiconductors, amorphous semiconductors offer inherent cost-effective, simple and uniform manufacturing. Traditional amorphous hydrogenated Si falls short in electrical properties, necessitating the exploration of new materials. The creation of high-mobility amorphous n-type metal oxides, such as a-InGaZnO (ref. ), and their integration into thin-film transistors (TFTs) have propelled advancements in modern large-area electronics and new-generation displays. However, finding comparable p-type counterparts poses notable challenges, impeding the progress of complementary metal-oxide-semiconductor technology and integrated circuits. Here we introduce a pioneering design strategy for amorphous p-type semiconductors, incorporating high-mobility tellurium within an amorphous tellurium suboxide matrix, and demonstrate its use in high-performance, stable p-channel TFTs and complementary circuits. Theoretical analysis unveils a delocalized valence band from tellurium 5p bands with shallow acceptor states, enabling excess hole doping and transport. Selenium alloying suppresses hole concentrations and facilitates the p-orbital connectivity, realizing high-performance p-channel TFTs with an average field-effect hole mobility of around 15 cm V s and on/off current ratios of 10-10, along with wafer-scale uniformity and long-term stabilities under bias stress and ambient ageing. This study represents a crucial stride towards establishing commercially viable amorphous p-channel TFT technology and complementary electronics in a low-cost and industry-compatible manner.
PubMed: 38599238
DOI: 10.1038/s41586-024-07360-w -
PloS One 2022We report a deep learning-based emotion recognition method using EEG data collected while applying cosmetic creams. Four creams with different textures were randomly...
We report a deep learning-based emotion recognition method using EEG data collected while applying cosmetic creams. Four creams with different textures were randomly applied, and they were divided into two classes, "like (positive)" and "dislike (negative)", according to the preference score given by the subject. We extracted frequency features using well-known frequency bands, i.e., alpha, beta and low and high gamma bands, and then we created a matrix including frequency and spatial information of the EEG data. We developed seven CNN-based models: (1) inception-like CNN with four-band merged input, (2) stacked CNN with four-band merged input, (3) stacked CNN with four-band parallel input, and stacked CNN with single-band input of (4) alpha, (5) beta, (6) low gamma, and (7) high gamma. The models were evaluated by the Leave-One-Subject-Out Cross-Validation method. In like/dislike two-class classification, the average accuracies of all subjects were 73.2%, 75.4%, 73.9%, 68.8%, 68.0%, 70.7%, and 69.7%, respectively. We found that the classification performance is higher when using multi-band features than when using single-band feature. This is the first study to apply a CNN-based deep learning method based on EEG data to evaluate preference for cosmetic creams.
Topics: Humans; Electroencephalography; Neural Networks, Computer; Deep Learning; Emotions; Research Design
PubMed: 36355917
DOI: 10.1371/journal.pone.0274203 -
Biomedical Materials (Bristol, England) Nov 2022Three-dimensional cell constructs comprising only tissue-specific cells and extracellular matrix secreted by them would be ideal transplants, but their fabrication in a...
Three-dimensional cell constructs comprising only tissue-specific cells and extracellular matrix secreted by them would be ideal transplants, but their fabrication in a cell aggregation manner without cell scaffolds relies on random cell self-aggregation, making the control of their size and shape difficult. In this study, we propose a method to fabricate band-shaped tissues by inducing the self-aggregation of cell sheets using the developed cell self-aggregation technique (CAT). Acting as cell aggregation stoppers, silicone semicircular pillars were attached to two positions equidistant from both short ends of the rounded rectangular culture groove and coated with a specifically charged biomimetic polymer as a CAT-inducing surface. Mesenchymal stem cells, chondrocytes, and skeletal myoblast cells seeded on the surface of the culture grooves formed band-shaped aggregates between the two aggregation stoppers following spontaneous detachment with aggregation of the cell sheet from the outer edge of the grooves during day one of culture. The aggregated chondrocyte band matured into a cartilage-like plate with an abundant cartilage matrix while retaining its band shape after two weeks of chondrogenic cultivation. Additionally, the aggregates of mesenchymal stem cells and myoblast cell bands could patch the induced collagen membrane derived from rat subcutaneous tissue like a bandage immediately after their formation and successfully mature into fat and muscle tissues, respectively. These results indicate that, depending on the cell type, scaffold-free band-shaped cell aggregates produced by CAT have the potential to achieve tissue regeneration that follows the shape of the defect viamaturation culture ororganization.
Topics: Rats; Animals; Chondrogenesis; Cartilage; Chondrocytes; Mesenchymal Stem Cells; Mesoderm
PubMed: 36270422
DOI: 10.1088/1748-605X/ac9c7f -
Cureus Jan 2022This study aimed to investigate the operator's ease, satisfaction, and comfort of using a circumferential matrix system and sectional matrix system on the proximal...
OBJECTIVES
This study aimed to investigate the operator's ease, satisfaction, and comfort of using a circumferential matrix system and sectional matrix system on the proximal contact points and contours when restoring class II cavities in posterior teeth.
MATERIALS AND METHODS
This cross-sectional study was performed at the clinics in the Department of Conservative Dental Sciences, College of Dentistry, Qassim University. A total of 105 dental students randomly participated in this study to restore a class II cavity with direct composite resin restoration. Operators' comfort and satisfaction were evaluated according to their assessment of the contact points they reproduced and the emergence profiles of restorations, using a circumferential matrix system and sectional matrix system.
RESULTS
Out of 105 operators, 57 were satisfied with using circumferential matrix bands for most of their cases while 78 of the operators were satisfied with sectional matrix bands. There were no significant differences between operator satisfaction and the use of circumferential matrix band system (P > 0.05) and sectional matrix band system (P = 0.134) but there was a significant difference between difficulty levels in the use of both matrix band systems (P < 0.05; P = 0.000).
CONCLUSION
Circumferential and sectional matrix band systems showed no significant differences with operators' satisfaction during restoring class II cavities in posterior teeth but using a sectional matrix band system was considered easier than using a circumferential matrix band system.
PubMed: 35004091
DOI: 10.7759/cureus.20957 -
Journal of Ayub Medical College,... 2023The reconstruction of proximal defects with tight contacts has always been a challenge for dental clinicians, especially with composite material. Recent literature shows...
BACKGROUND
The reconstruction of proximal defects with tight contacts has always been a challenge for dental clinicians, especially with composite material. Recent literature shows that the most frequently used matrix systems for the restoration of proximal cavities are circumferential or sectional matrix band systems. The objective of this study was to compare the contact tightness that is achieved with these two matrix band systems when using composite material.
METHODS
A total of 30 patients, i.e., 60 cavities were selected in this quasi-experimental study. Patients with two cavities in the posterior teeth were selected. Both the cavities were restored with the circumferential system, i.e., Tofflemire and sectional matrix band system, i.e., Palodent plus on the same appointment. Hence both systems were used in every patient and then contact tightness assess was ed based on an evaluation criterion, i.e., Fédération Dentaire Internationale clinical criteria for evaluation of contact in direct and indirect restorations. To make a comparison between the two systems Chi square test was used and p<0.05.
RESULTS
The mean age of the patients in the study was 31 years (SD, 7.59 years) with a range from 18 to 45 years. Most of the contact tightness in the Palodent matrix system was score 1 (n=33, 55%) and score 2 (n=17, 28.3%) while in Tofflemire was score 4 (n=28, 46.7%) and score 5 (n=19, 31.7%). Statistical analysis showed significance (p=.037) between Palodent matrix system contact tightness and Tofflemire.
CONCLUSION
The sectional matrix band system was statistically superior to the circumferential matrix band system in achieving a tighter contact for class II composite restorations.
Topics: Humans; Adolescent; Young Adult; Adult; Middle Aged; Composite Resins; Matrix Bands; Chi-Square Distribution; Margins of Excision
PubMed: 37422816
DOI: 10.55519/JAMC-02-11541 -
Heliyon Feb 2023This work presents W-band (75-110 GHz) dielectric characterization of commercially available photoresins in their neat state, as well as in polymer matrix composite...
This work presents W-band (75-110 GHz) dielectric characterization of commercially available photoresins in their neat state, as well as in polymer matrix composite (PMC) mixtures with various loading concentrations of the paraelectric barium strontium titanate (BST). Due to difficulties 3D printing the BST-loaded PMC resins detailed within, a custom curing and casting process was used to fabricate testable PMC samples, which were synthesized to demonstrate the dielectric functionalization of the underlying polymer matrix. Dielectric characterization of the PMCs confirmed the functionalization of our composites when compared to the commercial photoresins. For example, a volumetric loading concentration of 25 vol % BST increased the dielectric permittivity ( ) from 2.78 to 9.60 and the loss tangent (tanδ) from 0.022 to 0.114. These results indicate that the realization of UV-cured photoresins with "designer-dielectric" functionalization based on vol % of filler are strong candidates for use in stereolithography (SLA) 3D printing applications. To accomplish this, and with a special interest for radio/microwave/terahertz (RF/MW/THz) applications, we highlight the need for both (a) better photoresin matrix materials with lower intrinsic tanδ and (b) selection criteria related to the size/geometry and electronic properties of potential filler materials to maintain the printability of PMC photoresins in SLA systems.
PubMed: 36825176
DOI: 10.1016/j.heliyon.2023.e13458 -
Journal of Clinical Neurology (Seoul,... Apr 2019We aimed to reveal resting-state functional connectivity characteristics based on the spike-free waking electroencephalogram (EEG) of benign epilepsy with centrotemporal...
BACKGROUND AND PURPOSE
We aimed to reveal resting-state functional connectivity characteristics based on the spike-free waking electroencephalogram (EEG) of benign epilepsy with centrotemporal spikes (BECTS) patients, which usually appears normal in routine visual inspection.
METHODS
Thirty BECTS patients and 30 disease-free and age- and sex-matched controls were included. Eight-second EEG epochs without artifacts were sampled and then bandpass filtered into the delta, theta, lower alpha, upper alpha, and beta bands to construct the association matrix. The weighted phase lag index (wPLI) was used as an association measure for EEG signals. The band-specific connectivity, which was represented as a matrix of wPLI values of all edges, was compared for analyzing the connectivity itself. The global wPLI, characteristic path length (CPL), and mean clustering coefficient were compared.
RESULTS
The resting-state functional connectivity itself and the network topology differed in the BECTS patients. For the lower-alpha-band and beta-band connectivity, edges that showed significant differences had consistently lower wPLI values compared to the disease-free controls. The global wPLI value was significantly lower for BECTS patients than for the controls in lower-alpha-band connectivity (mean±SD; 0.241±0.034 vs. 0.276±0.054, =0.024), while the CPL was significantly longer for BECTS in the same frequency band (mean±SD; 4.379±0.574 vs. 3.904±0.695, =0.04). The resting-state functional connectivity of BECTS showed decreased connectivity, integration, and efficiency compared to controls.
CONCLUSIONS
The connectivity differed significantly between BECTS patients and disease-free controls. In BECTS, global connectivity was significantly decreased and the resting-state functional connectivity showed lower efficiency in the lower alpha band.
PubMed: 30938108
DOI: 10.3988/jcn.2019.15.2.211 -
Frontiers in Dentistry 2023Hardness is relevant to the degree of conversion (DC) and depth of cure (DoC). The aim of this study was to determine the micro-hardness and DoC of conventional and...
Hardness is relevant to the degree of conversion (DC) and depth of cure (DoC). The aim of this study was to determine the micro-hardness and DoC of conventional and bulk-fill composite resins in class II restorations using metal and clear matrix bands. Twelve specimens of each of the two composite resins, , Filtek Z350 XT bulk-fill and Gradia posterior conventional composite, were prepared in the form of a class II cavity in a tooth mold, using a clear or metal matrix band. All specimens were cured and stored at 37°C for 24 hours. Vickers hardness was measured as a function of DoC at 2mm intervals. Data were analyzed by two-way ANOVA (alpha=0.05). The bulk-fill composite exhibited significantly higher hardness levels than the conventional composite in all tested surfaces (P<0.001). However, while the metal matrix band had a significant impact on the bottom surface (P=0.059) and also on the furthest surface from the matrix and light source (P=0.04), it did not have a consistent effect across all tested surfaces. The simultaneous interaction of the composites and matrix band types in all surfaces, did not show significant differences in hardness values. The highest bottom-to-top surface hardness ratio (73%) was observed in the conventional composite near the metal matrix band. In deep class II cavities, the bottom-to-top surface hardness ratio did not reach the maximum of 80%, neither for bulk-fill nor conventional posterior composites. Therefore, in such cavities extended light-curing and more incremental composite placement is needed.
PubMed: 37701657
DOI: 10.18502/fid.v20i20.12912 -
Materials (Basel, Switzerland) Feb 2022Understanding the mechanisms of deformation and fracture of metastable β titanium alloys is of great significance for improving formability and service life. By...
Understanding the mechanisms of deformation and fracture of metastable β titanium alloys is of great significance for improving formability and service life. By combining the in-situ tensile test, TEM characterization and EBSD analysis, the tensile deformation behavior, activation of slip systems, crack initiation, and propagation of a high strength metastable β titanium alloy (Ti-5Cr-4Al-4Zr-3Mo-2W-0.8Fe) with equiaxed microstructure are investigated. The equiaxed microstructure is composed of primary α (α) phase, transformed β (β) matrix phase, and secondary α (α) phase. In contrast to the hexagonal α grain with limited slip systems, the body-centered β matrix has more slip systems, however the hindering effect of α phases on dislocation slip leads to the different deformability of the α phase and β matrix. The equiaxed α grains are more prone to deformation and rotation to coordinate the overall deformation. The shear band leads to the formation of sub-grain boundary and even the fragmentation of α grains. As a result, the microvoids tend to nucleate at the grain boundary, phase interface, slip band, and shear band. The inhomogeneous deformation in the plastic deformation zone around the crack tip is the primary cause of damage. The crack propagation caused by microvoids coalescence advances along the grain boundaries and phase interfaces in the form of intergranular, and along the activated slip systems and shear bands in the form of transgranular. Pinpointing the situation in the equiaxed microstructure and combining that in other typical microstructures will help to summarize the universal deformation and fracture mechanisms of metastable β titanium alloy, and provide a basis for alloy design and microstructure tailoring.
PubMed: 35207866
DOI: 10.3390/ma15041325