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1.
Dev Biol ; 516: 1-19, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39069116

RESUMO

Thanks to their exceptional diversity, teeth are among the most distinctive features of vertebrates. Parameters such as tooth size, shape, number, identity, and implantation can have substantial implications for the ecology and certain social behaviors of toothed species. Despite decades of research primarily focused on mammalian dentition, particularly using the laboratory mouse model, squamate reptiles ("lizards" and snakes) offer a wide array of tooth types and dentition variations. This diversity, which includes differences in size, shape, function, and replacement capacity, provides invaluable opportunities for investigating these fundamental properties. The central bearded dragon (Pogona vitticeps), a popular pet species with well-established husbandry practices, is of particular interest. It features a broad spectrum of morphs and spontaneous mutants and exhibits a wide range of heterodont phenotypes, including variation in the size, shape, number, implantation, and renewal of teeth at both posterior and anterior positions. These characteristics position the species as a crucial model organism for developmental studies in tooth research and for gaining deeper insights into evolutionary patterns of vertebrate dentitions. In this article, we provide an overview of the current understanding of squamate dentition, its diversity, development, and replacement. Furthermore, we discuss the significant advantages offered by squamate species as model organisms for investigating the evolutionary and developmental aspects of vertebrate dentition.

2.
Exp Cell Res ; 442(1): 114186, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39098465

RESUMO

TGFß1 is a powerful regulator of fibrosis; secreted in a latent form, it becomes active after release from the latent complex. During tissue fibrosis, the EDA + isoform of cellular fibronectin is overexpressed. In pulmonary fibrosis it has been proposed that the fibronectin splice variant including an EDA domain (FN EDA+) activates latent TGFß. Our work investigates the potential of blocking the 'splicing in' of EDA with antisense oligonucleotides to inhibit TGFß1-induced EDA + fibronectin and to prevent the cascade of events initiated by TGFß1 in human renal proximal tubule cells (PTEC). Human primary PTEC were treated with TGFß1 for 48 h, medium removed and the cells transfected with RNase H-independent antisense oligonucleotides (ASO) designed to block EDA exon inclusion (ASO5). The efficacy of ASO to block EDA exon inclusion was assessed by EDA + fibronectin RNA and protein expression; the expression of TGFß, αSMA (α smooth muscle actin), MMP2 (matrix metalloproteinse-2), MMP9 (matrix metalloproteinse-9), Collagen I, K Cadherin and connexin 43 was analysed. Targeting antisense oligonucleotides designed to block EDA exon inclusion in fibronectin pre mRNA were effective in reducing the amount of TGFß1 -induced cellular EDA + fibronectin RNA and secreted EDA + fibronectin protein (assessed by western immunoblotting and immunocytochemistry) in human proximal tubule cells in an in vitro cell culture model. The effect was selective for EDA + exon with no effect on EDB + fibronectin RNA and total fibronectin mRNA. Exogenous TGFß1 induced endogenous TGFß, αSMA, MMP2, MMP9 and Col I mRNA. TGFß1 treatment for 48h reduced the expression of K-Cadherin and increased the expression of connexin-43. These TGFß1-induced pro-fibrotic changes were attenuated by ASO5 treatment. 48 h after the removal of exogenous TGFß, further increases in αSMA, MMP2, MMP9 was observed; ASO5 significantly inhibited this subsequent increase. ASO5 treatment also significantly inhibited ability of the cell culture medium harvested at the end of the experiment (96h) to stimulate SMAD3 reporter cells. The role of endogenous TGFß1 was confirmed by the use of a TGFß receptor inhibitor. Our results demonstrate a critical role of FN EDA+ in a cycle of TGFß driven pro-fibrotic responses in human PTEC and blocking its production with ASO technology offers a potential therapy to interrupt this vicious circle and hence limit the progression of renal fibrosis.

3.
J Comput Chem ; 45(14): 1098-1111, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38261518

RESUMO

CO2 reduction is appealing for the long-term production of high-value fuels and chemicals. Herein, using density functional theory (DFT) based calculations, we study the CO2 reduction pathway to formic acid using aluminum hydride and phosphine derivatives. Our primary focus is on aluminum hydride derivatives, aimed at improving the efficiency of the CO2 reduction process. Substituents with σ-donating properties at the aluminum center are discovered to lower the activation barriers. We demonstrate how di-tert-butylphosphine oxide (LB-O)/di-tert-butylphosphine sulfide (LB-S)/di-tert-butylphosphanimine (LB-N) work together with aluminum hydride to facilitate CO2 reduction process and generate in-situ frustrated Lewis pairs (FLPs), such as FLP-O, FLP-S, and FLP-N. The activation strain model (ASM) analysis reveals the significance of strain energy in determining activation barriers. EDA-NOCV and PIO analyses elucidate the orbital interactions at the corresponding transition states. Furthermore, the study delves into the activation of various small molecules, such as dihydrogen, acetylene, ethylene, carbon dioxide, nitrous oxide, and acetonitrile, using those in-situ generated FLPs. The study highlights the low activation barriers and emphasizes the potential for small molecule activation in this context.

4.
J Comput Chem ; 45(11): 804-819, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38135467

RESUMO

The inability of p-block elements to participate in π-backbonding restricts them from activating small molecules like CO, H2 , and so forth. However, the development of the main group metallomimetics became a new pathway, where the main-group elements like boron can bind and activate small molecules like CO and H2 . The concept of the frustrated Lewis pair, Boron-Boron multiple bonds, and borylene are previously illustrated. Some of these reported classes of boron species can mimic the jobs of the metal complexes. Hence, we have theoretically studied the binding of CO/N2 molecules at B-center of elusive species like sila/germa boryne stabilized by donor base ligands (cAAC)BE(Me)(L), where E  Si, L  cAACMe , NHCMe , PMe3 , E  Ge, L  cAACMe and (NHCMe )BE(Me)(cAACMe )). The substitutional analogues of (cAACR )BSiR1 (cAAC) and E  P, L  cAACMe ) have been studied by density functional theory (DFT), natural bond orbital, QTAIM calculations and energy decomposition analysis (EDA) coupled with natural orbital for chemical valence (NOCV) analyses. The computed bond dissociation energy and inner stability analyses by the EDA-NOCV method showed that the CO molecule can bind at the B-center of the above-mentioned species due to stronger σ-donor ability while binding of N2 has been theoretically predicted to be weak. The energy barrier for the CO binding is estimated to be 13-14 kcal/mol by transition state calculation. The change of partial triple bond character to single bond nature of the BSi bond and the bending of CBSi bond angle of sila-boryne species are the reason for the activation energy. Our study reveals the ability of such species to bind and activate the CO molecule to mimic the transition metal-containing complexes. We have additionally shown that binding of Fe(CO)4 and Ni(CO)3 is feasible at Si-center after binding of CO at the B-center.

5.
Chemistry ; 30(41): e202401546, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-38716768

RESUMO

We have established a facile and efficient protocol for the generation of germyl radicals by employing photo-excited electron transfer (ET) in an electron donor-acceptor (EDA) complex to drive hydrogen-atom transfer (HAT) from germyl hydride (R3GeH). Using a catalytic amount of EDA complex of commercially available thiol and benzophenone derivatives, the ET-HAT cycle smoothly proceeds simply upon blue-light irradiation without any transition metal or photocatalyst. This protocol also affords silyl radical from silyl hydride.

6.
Chemistry ; 30(31): e202400193, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38546345

RESUMO

Photoinduced aryl radical generation is a powerful strategy in organic synthesis that facilitates the formation of diverse carbon-carbon and carbon-heteroatom bonds. The synthetic applications of photoinduced aryl radical formation in the synthesis of complex organic compounds, including natural products, physiologically significant molecules, and functional materials, have received immense attention. An overview of current developments in photoinduced aryl radical production methods and their uses in organic synthesis is given in this article. A generalized idea of how to choose the reagents and approach for the generation of aryl radicals is described, along with photoinduced techniques and associated mechanistic insights. Overall, this article offers a critical assessment of the mechanistic results as well as the selection of reaction parameters for specific reagents in the context of radical cascades, cross-coupling reactions, aryl radical functionalization, and selective C-H functionalization of aryl substrates.

7.
Chemistry ; 30(30): e202400905, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38536766

RESUMO

Blue LEDs-irradiation of a mixture of N,N,N',N'-tetramethylethylenediamine (TMEDA) and perfluoroalkyl iodides (RF-I) - Electron Donor Acceptor (EDA)-complex - in the presence of triphenylamines (TPAs) in an aqueous solvent mixture afforded mono-perfluoroalkylated triphenylamines (RF-TPA) in good yields. These RF-TPA were further subjected to acetone-sensitized [6π]-electrocyclization at 315 nm-irradiation affording exclusively perfluoroalkylated endo-carbazole derivatives (RF-CBz) in quantitative yields. Mechanistic studies and photophysical properties of products are studied.

8.
Chemistry ; 30(34): e202400714, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38622057

RESUMO

Quantum chemical calculations using ab initio methods at the MRCI+Q(8,9)/def2-QZVPPD and CCSD(T)/def2-QZVPPD levels as well as using density functional theory are reported for the diatomic molecules AeN- (Ae=Ca, Sr, Ba). The anions CaN- and SrN- have electronic triplet (3Π) ground states with nearly identical bond dissociation energies De ~57 kcal/mol calculated at the MRCI+Q(8,9)/def2-QZVPPD level. In contrast, the heavier homologue BaN- has a singlet (1Σ+) ground state, which is only 1.1 kcal/mol below the triplet (3Σ-) state. The computed bond dissociation energy of (1Σ+) BaN- is 68.4 kcal/mol. The calculations at the CCSD(T)-full/def2-QZVPPD and BP86-D3(BJ)/def2-QZVPPD levels are in reasonable agreement with the MRCI+Q(8,9)/def2-QZVPPD data, except for the singlet (1Σ+) state, which has a large multireference character. The calculated atomic partial charges given by the CM5, Voronoi and Hirshfeld methods suggest small to medium-sized Ae←N- charge donation for most electronic states. In contrast, the NBO method predicts for all species medium to large Ae→N- electronic charge donation, which is due to the neglect of the (n)p AOs of Ae atoms as genuine valence orbitals. Neither the bond orders nor the bond lengths correlate with the bond dissociation energies. The EDA-NOCV calculations show that the heavier alkaline earth atoms Ca, Sr, Ba use their (n)s and (n-1)d orbitals for covalent bonding.

9.
Chemistry ; 30(33): e202400658, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38600038

RESUMO

Photoinduced single-electron reduction is an efficient method for the mono-selective activation of the C-F bond on a trifluoromethyl group to construct a difluoroalkyl group. We have developed an electron-donor-acceptor (EDA) complex mediated single-electron transfer (EDA-SET) of α,α,α-trifluoromethyl arenes in the presence of lithium salt to give α,α-difluoroalkylarenes. The C-F bond reduction was realized by lithium iodide and triethylamine, two common feedstock reagents. Mechanistic studies revealed the generation of a α,α-difluoromethyl radical by single-electron reduction and defluorination, followed by the radical addition to alkenes. Lithium salt interacted with the fluorine atom to promote the photoinduced reduction mediated by the EDA complex. Computational studies indicated that the lithium-assisted defluorination and the single-electron reduction occurred concertedly. We call this phenomenon fluoride-coupled electron transfer (FCET). FCET is a novel approach to C-F bond activation for the synthesis of organofluorine compounds.

10.
Anal Biochem ; 689: 115499, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38431141

RESUMO

MicroRNAs (miRNAs) are crucial biomarkers for the early detection and monitoring of disease progression of chronic obstructive pulmonary disease (COPD). Herein, we have devised a method for detecting miRNA using a combination of colorimetric and graphene oxide-based fluorescent techniques. The target miRNA in our design could precisely activate the trans-cleavage activity of the CRISPR-Cas13a system. The activated Cas13a enzyme cuts the "rUrU" section in the P1 probe, generating a nicking site to induce entropy-driven amplification (EDA). One of the available EDA products has the capability to unfold the hairpin probe, thereby initiating the catalytic hairpin assembly, exposing the G-quadruplex structure, facilitating the subsequent color response. The fuel strand labeled with Cy3 successfully established a double-stranded DNA structure with DNA3, and consequently the Cy3 would not be quenched by graphene oxide (GO). The implementation of the dual-mode technique in this method yields greater benefits in terms of improving the precision and consistency of the miRNA measurements. The developed method has the capability to fluorescently measure miRNA-21 levels down to a concentration of 5.8 fM. In addition, the analysis of miRNA targets from clinical samples using this method demonstrates its promising utility in the fields of biomedical research of COPD.


Assuntos
Técnicas Biossensoriais , Grafite , MicroRNAs , Doença Pulmonar Obstrutiva Crônica , Humanos , MicroRNAs/genética , Colorimetria/métodos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Entropia , Técnicas de Amplificação de Ácido Nucleico/métodos , Corantes
11.
Anal Biochem ; 693: 115593, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38885872

RESUMO

MicroRNA (miRNA) is a pivotal biomarker in the diagnosis of various cancers, including bladder cancer (BCa). Despite their significance, the low abundance of miRNA presents a substantial challenge for sensitive and reliable detection. We introduce an innovative, highly sensitive assay for miRNA expression quantification that is both enzyme-free and portable. This method leverages the synergy of target recycling and entropy-driven assembly (EDA) for enhanced sensitivity and specificity. The proposed method possesses several advantages, including i) dual signal amplification through target recycling and EDA, which significantly boosts sensitivity with a lower limit of detection of 2.54 fM; ii) elimination of enzyme requirements, resulting in a cost-effective and stable signal amplification process; and iii) utilization of a personal glucose meter (PGM) for signal recording, rendering the method portable and adaptable to diverse settings. In summary, this PGM-based approach holds promising potential for clinical molecular diagnostics, offering a practical and efficient solution for miRNA analysis in cancer detection.


Assuntos
Entropia , MicroRNAs , MicroRNAs/análise , MicroRNAs/genética , Humanos , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/genética , Limite de Detecção , Técnicas Biossensoriais/métodos , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/análise
12.
Chem Rec ; : e202400055, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38994665

RESUMO

Carbon-based allotropes are propelling a technological revolution in communication, sensing, and computing, concurrently challenging fundamental theories of the previous century. Nevertheless, the demand for advanced carbon-based materials remains substantial. The crux lies in the efficient and reliable engineering of novel carbon allotrope. Although C18 has undergone theoretical and experimental investigation for an extended period, its preparation and direct observation in the condensed phase occurred only recently through STM/AFM techniques. The distinctive cyclic ring structure and the dual 18-center π delocalization character introduce various uncommon properties to C18, rendering it a subject worthy of in-depth exploration. In this context, this review delves into past developments contributing to the state-of-the-art understanding of C18 and provides insights into how future endeavours can expedite practical applications. Encompassing a broad spectrum, this review comprehensively investigates almost all facets of C18, including geometric characteristics, electron delocalization, bonding nature, aromaticity, reactivity, electronic excitation, UV/Vis spectrum, intermolecular interaction, response to external fields, electron affinity, ionization, and other molecular properties. Moreover, the review also outlines representative strategies for the direct synthesis and characterization of C18 using atom manipulation techniques. Following this, C18-based complexes are summarized, and potential applications in catalysis, electrochemical devices, optoelectronics, and sensing are discussed.

13.
Environ Sci Technol ; 58(23): 9925-9944, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38820315

RESUMO

Organic contaminants are ubiquitous in the environment, with mounting evidence unequivocally connecting them to aquatic toxicity, illness, and increased mortality, underscoring their substantial impacts on ecological security and environmental health. The intricate composition of sample mixtures and uncertain physicochemical features of potential toxic substances pose challenges to identify key toxicants in environmental samples. Effect-directed analysis (EDA), establishing a connection between key toxicants found in environmental samples and associated hazards, enables the identification of toxicants that can streamline research efforts and inform management action. Nevertheless, the advancement of EDA is constrained by the following factors: inadequate extraction and fractionation of environmental samples, limited bioassay endpoints and unknown linkage to higher order impacts, limited coverage of chemical analysis (i.e., high-resolution mass spectrometry, HRMS), and lacking effective linkage between bioassays and chemical analysis. This review proposes five key advancements to enhance the efficiency of EDA in addressing these challenges: (1) multiple adsorbents for comprehensive coverage of chemical extraction, (2) high-resolution microfractionation and multidimensional fractionation for refined fractionation, (3) robust in vivo/vitro bioassays and omics, (4) high-performance configurations for HRMS analysis, and (5) chemical-, data-, and knowledge-driven approaches for streamlined toxicant identification and validation. We envision that future EDA will integrate big data and artificial intelligence based on the development of quantitative omics, cutting-edge multidimensional microfractionation, and ultraperformance MS to identify environmental hazard factors, serving for broader environmental governance.


Assuntos
Monitoramento Ambiental , Monitoramento Ambiental/métodos , Poluentes Ambientais , Fracionamento Químico
14.
Anal Bioanal Chem ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992177

RESUMO

The rapid increase in the production and global use of chemicals and their mixtures has raised concerns about their potential impact on human and environmental health. With advances in analytical techniques, in particular, high-resolution mass spectrometry (HRMS), thousands of compounds and transformation products with potential adverse effects can now be detected in environmental samples. However, identifying and prioritizing the toxicity drivers among these compounds remain a significant challenge. Effect-directed analysis (EDA) emerged as an important tool to address this challenge, combining biotesting, sample fractionation, and chemical analysis to unravel toxicity drivers in complex mixtures. Traditional EDA workflows are labor-intensive and time-consuming, hindering large-scale applications. The concept of high-throughput (HT) EDA has recently gained traction as a means of accelerating these workflows. Key features of HT-EDA include the combination of microfractionation and downscaled bioassays, automation of sample preparation and biotesting, and efficient data processing workflows supported by novel computational tools. In addition to microplate-based fractionation, high-performance thin-layer chromatography (HPTLC) offers an interesting alternative to HPLC in HT-EDA. This review provides an updated perspective on the state-of-the-art in HT-EDA, and novel methods/tools that can be incorporated into HT-EDA workflows. It also discusses recent studies on HT-EDA, HT bioassays, and computational prioritization tools, along with considerations regarding HPTLC. By identifying current gaps in HT-EDA and proposing new approaches to overcome them, this review aims to bring HT-EDA a step closer to monitoring applications.

15.
Oral Dis ; 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38287639

RESUMO

OBJECTIVE: Tooth agenesis is a common craniofacial malformation, which is often associated with gene mutations. The purpose of this research was to investigate and uncover ectodysplasin A (EDA) gene variants in eight Chinese families affected with tooth agenesis. METHODS: Genomic DNA was extracted from tooth agenesis families and sequenced using whole-exome sequencing. The expression of ectodysplasin A1 (EDA1) protein was studied by western blot, binding activity with receptor was tested by pull-down and the NF-κB transcriptional activity was analyzed by Dual luciferase assay. RESULTS: Eight EDA missense variants were discovered, of which two (c.T812C, c.A1073G) were novel. The bioinformatics analysis indicated that these variants might be pathogenic. The tertiary structure analysis revealed that these eight variants could cause structural damage to EDA proteins. In vitro functional studies demonstrated that the variants greatly affect protein stability or impair the EDA-EDAR interaction; thereby significantly affecting the downstream NF-κb transcriptional activity. In addition, we summarized the genotype-phenotype correlation caused by EDA variants and found that EDA mutations leading to NSTA are mostly missense mutations located in the TNF domain. CONCLUSION: Our results broaden the variant spectrum of the EDA gene associated with tooth agenesis and provide valuable information for future genetic counseling.

16.
Sensors (Basel) ; 24(14)2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39065963

RESUMO

Electrodermal Activity (EDA), which primarily indicates arousal through sympathetic nervous system activity, serves as a tool to measure constructs like engagement, cognitive load, performance, and stress. Despite its potential, empirical studies have often yielded mixed results and found it of limited use. To better understand EDA, we conducted a mixed-methods study in which quantitative EDA profiles and survey data were investigated using qualitative interviews. This study furnishes an EDA dataset measuring the engagement levels of seven participants who watched three videos for 4-10 min. The subsequent interviews revealed five EDA morphologies with varying short-term signatures and long-term trends. We used this dataset to demonstrate the moving average crossover, a novel metric for EDA analysis, in predicting engagement-disengagement dynamics in such data. Our contributions include the creation of the detailed dataset, comprising EDA profiles annotated with qualitative data, the identification of five distinct EDA morphologies, and the proposition of the moving average crossover as an indicator of the beginning of engagement or disengagement in an individual.


Assuntos
Resposta Galvânica da Pele , Humanos , Resposta Galvânica da Pele/fisiologia , Masculino , Feminino , Adulto , Adulto Jovem , Nível de Alerta/fisiologia
17.
Sensors (Basel) ; 24(3)2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38339758

RESUMO

Assessing drivers' mental workload is crucial for reducing road accidents. This study examined drivers' mental workload in a simulated auditory-based dual-task driving scenario, with driving tasks as the main task, and auditory-based N-back tasks as the secondary task. A total of three levels of mental workload (i.e., low, medium, high) were manipulated by varying the difficulty levels of the secondary task (i.e., no presence of secondary task, 1-back, 2-back). Multimodal measures, including a set of subjective measures, physiological measures, and behavioral performance measures, were collected during the experiment. The results showed that an increase in task difficulty led to increased subjective ratings of mental workload and a decrease in task performance for the secondary N-back tasks. Significant differences were observed across the different levels of mental workload in multimodal physiological measures, such as delta waves in EEG signals, fixation distance in eye movement signals, time- and frequency-domain measures in ECG signals, and skin conductance in EDA signals. In addition, four driving performance measures related to vehicle velocity and the deviation of pedal input and vehicle position also showed sensitivity to the changes in drivers' mental workload. The findings from this study can contribute to a comprehensive understanding of effective measures for mental workload assessment in driving scenarios and to the development of smart driving systems for the accurate recognition of drivers' mental states.


Assuntos
Atenção , Condução de Veículo , Atenção/fisiologia , Carga de Trabalho , Análise e Desempenho de Tarefas , Movimentos Oculares , Acidentes de Trânsito
18.
Sensors (Basel) ; 24(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38339639

RESUMO

The quantification of comfort in binding parts, essential human-machine interfaces (HMI) for the functioning of rehabilitation robots, is necessary to reduce physical strain on the user despite great achievements in their structure and control. This study aims to investigate the physiological impacts of binding parts by measuring electrodermal activity (EDA) and tissue oxygen saturation (StO2). In Experiment 1, EDA was measured from 13 healthy subjects under three different pressure conditions (10, 20, and 30 kPa) for 1 min using a pneumatic cuff on the right thigh. In Experiment 2, EDA and StO2 were measured from 10 healthy subjects for 5 min. To analyze the correlation between EDA parameters and the decrease in StO2, a survey using the visual analog scale (VAS) was conducted to assess the level of discomfort at each pressure. The EDA signal was decomposed into phasic and tonic components, and the EDA parameters were extracted from these two components. RM ANOVA and a post hoc paired t-test were used to determine significant differences in parameters as the pressure increased. The results showed that EDA parameters and the decrease in StO2 significantly increased with the pressure increase. Among the extracted parameters, the decrease in StO2 and the mean SCL proved to be effective indicators. Such analysis outcomes would be highly beneficial for studies focusing on the comfort assessment of the binding parts of rehabilitation robots.


Assuntos
Resposta Galvânica da Pele , Saturação de Oxigênio , Humanos , Escala Visual Analógica , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Medição da Dor , Oxigênio/análise
19.
Sensors (Basel) ; 24(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38793858

RESUMO

Inertial signals are the most widely used signals in human activity recognition (HAR) applications, and extensive research has been performed on developing HAR classifiers using accelerometer and gyroscope data. This study aimed to investigate the potential enhancement of HAR models through the fusion of biological signals with inertial signals. The classification of eight common low-, medium-, and high-intensity activities was assessed using machine learning (ML) algorithms, trained on accelerometer (ACC), blood volume pulse (BVP), and electrodermal activity (EDA) data obtained from a wrist-worn sensor. Two types of ML algorithms were employed: a random forest (RF) trained on features; and a pre-trained deep learning (DL) network (ResNet-18) trained on spectrogram images. Evaluation was conducted on both individual activities and more generalized activity groups, based on similar intensity. Results indicated that RF classifiers outperformed corresponding DL classifiers at both individual and grouped levels. However, the fusion of EDA and BVP signals with ACC data improved DL classifier performance compared to a baseline DL model with ACC-only data. The best performance was achieved by a classifier trained on a combination of ACC, EDA, and BVP images, yielding F1-scores of 69 and 87 for individual and grouped activity classifications, respectively. For DL models trained with additional biological signals, almost all individual activity classifications showed improvement (p-value < 0.05). In grouped activity classifications, DL model performance was enhanced for low- and medium-intensity activities. Exploring the classification of two specific activities, ascending/descending stairs and cycling, revealed significantly improved results using a DL model trained on combined ACC, BVP, and EDA spectrogram images (p-value < 0.05).


Assuntos
Acelerometria , Algoritmos , Aprendizado de Máquina , Fotopletismografia , Humanos , Fotopletismografia/métodos , Acelerometria/métodos , Masculino , Adulto , Processamento de Sinais Assistido por Computador , Feminino , Atividades Humanas , Resposta Galvânica da Pele/fisiologia , Dispositivos Eletrônicos Vestíveis , Adulto Jovem
20.
Sensors (Basel) ; 24(15)2024 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-39124100

RESUMO

The orienting reaction (OR) towards a new stimulus is subject to habituation, i.e., progressively attenuates with stimulus repetition. The skin conductance responses (SCRs) are known to represent a reliable measure of OR at the peripheral level. Yet, it is still a matter of debate which of the P3 subcomponents is the most likely to represent the central counterpart of the OR. The aim of the present work was to study habituation, recovery, and dishabituation phenomena intrinsic to a two-stimulus auditory oddball paradigm, one of the most-used paradigms both in research and clinic, by simultaneously recording SCRs and P3 in twenty healthy volunteers. Our findings show that the target stimulus was capable of triggering a more marked OR, as indexed by both SCRs and P3, compared to the standard stimulus, that could be due to its affective saliency and relevance for task completion; the application of temporal principal components analysis (PCA) to the P3 complex allowed us to identify several subcomponents including both early and late P3a (eP3a; lP3a), P3b, novelty P3 (nP3), and both a positive and a negative Slow Wave (+SW; -SW). Particularly, lP3a and P3b subcomponents showed a similar behavior to that observed for SCRs , suggesting them as central counterparts of OR. Finally, the P3 evoked by the first standard stimulus after the target showed a significant dishabituation phenomenon which could represent a sign of the local stimulus change. However, it did not reach a sufficient level to trigger an SCR/OR since it did not represent a salient event in the context of the task.


Assuntos
Estimulação Acústica , Resposta Galvânica da Pele , Habituação Psicofisiológica , Humanos , Masculino , Adulto , Feminino , Resposta Galvânica da Pele/fisiologia , Habituação Psicofisiológica/fisiologia , Estimulação Acústica/métodos , Adulto Jovem , Análise de Componente Principal , Eletroencefalografia/métodos , Tempo de Reação/fisiologia
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