Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
BMC Public Health ; 24(1): 1645, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902622

RESUMO

INTRODUCTION: Wearing a helmet reduces the risk of head injuries substantially in the event of a motorcycle crash. Countries around the world are committed to promoting helmet use, but the progress has been slow and uneven. There is an urgent need for large-scale data collection for situation assessment and intervention evaluation. METHODS: This study proposes a scalable, low-cost algorithm to estimate helmet-wearing rates. Applying the state-of-the-art deep learning technique for object detection to images acquired from Google Street View, the algorithm has the potential to provide accurate estimates at the global level. RESULTS: Trained on a sample of 3995 images, the algorithm achieved high accuracy. The out-of-sample prediction results for all three object classes (helmets, drivers, and passengers) reveal a precision of 0.927, a recall value of 0.922, and a mean average precision at 50 (mAP50) of 0.956. DISCUSSION: The remarkable model performance suggests the algorithm's capacity to generate accurate estimates of helmet-wearing rates from an image source with global coverage. The significant enhancement in the availability of helmet usage data resulting from this approach could bolster progress tracking and facilitate evidence-based policymaking for helmet wearing globally.


Assuntos
Aprendizado Profundo , Dispositivos de Proteção da Cabeça , Dispositivos de Proteção da Cabeça/estatística & dados numéricos , Humanos , Algoritmos , Acidentes de Trânsito/prevenção & controle , Traumatismos Craniocerebrais/prevenção & controle
2.
Molecules ; 28(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36677573

RESUMO

In this work, a novel AaBAb-type triblock polycarboxylate superplasticizers (PCEs) with well defined molecular structures were designed and synthesized, firstly, by reversible addition-fragmentation chain transfer (RAFT) polymerization, to explore the structure-property relationship PCEs in the ß-hemihydrate gypsum (ß-HH) system. Three PCEs with the same molecular weight and different structure were obtained by changing the feed ratio of the RAFT agent, initiator, and monomer. The effect of the chemical structure of PCEs on their dispersing property and water reduction capacity were assessed in gypsum by measuring the flowability of pastes and the adsorption ability of PCEs on gypsum. Results showed that among three PCEs, when the monomer ratio is 5:1 and a:b = 1:1, PCE-1 exhibited a higher working efficiency, verifying the contribution of regulating structural parameters to the improvement in performances of gypsum paste, because PCE-1 showed the strongest binding capacity with calcium ions due to the relatively equal amount of carboxyl groups at both ends. The AaBAb-type PCEs provide a special advantage over the conventional comb polymer to understand the relation between the structure and property of PCEs, and a direction for further development of PCEs of high performance.

3.
Mediators Inflamm ; 2022: 2558275, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35784175

RESUMO

Methods: The data sets of GSE56081 and GSE63492 in the Gene Expression Omnibus (GEO) database were used for screening and analysis, and the key gene markers were verified by GSE34095 and GSE126883. Finally, the infiltration of immune cells in the data were analyzed by MCPcounter analysis package. Results: In this study, a ceRNA containing 15 lncRNAs, 9 miRNAs, and 103 mRNAs was constructed. After multimodel screening and verification, key gene marker was found, namely, ATF2. The lncRNA/miRNA/mRNA axis closely related to ATF2 have also been found, namely, SNHG5/miR-299-5p/ATF2. In the analysis of immune infiltration, ATF2 was negatively correlated with T cells but positively correlated with neutrophils and endothelial cells. Conclusion: The SNHG5/miR-299-5p/ATF2 can be used as biomarker of IDD, and infiltration of immune cells plays an important role in the pathological development of IDD. In addition, as a marker of IDD, the involvement of the above-mentioned axis in the pathological development of IDD remains to be further explored.


Assuntos
Degeneração do Disco Intervertebral , MicroRNAs , RNA Longo não Codificante , Fator 2 Ativador da Transcrição/genética , Biomarcadores , Células Endoteliais/metabolismo , Humanos , Degeneração do Disco Intervertebral/genética , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro
4.
Neural Plast ; 2022: 9762244, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35510269

RESUMO

Objective: This study is to explore key immune markers and changes of immune microenvironment in neuropathic pain (NeuP). Method: The data sets of GSE145199 and GSE145226 in Gene Expression Omnibus (GEO) database was used to analyze, and the key immune markers were verified by GSE70006 and GSE91396, and the infiltration degree of immune cells in different samples were analyzed by CIBERSORT analysis package. Results: In this study, we found a key immune marker, namely, LANCL1. Regulatory axis closely related to LANCL1 has also been found, namely, miR-6325/LANCL1 axis. In the immune infiltration analysis, we also found that the LANCL1 is positively correlated with T cells CD4 naïve (r = 0.880, p < 0.05). Conclusion: In this study, we found that LANCL1 may be a protective factor for NeuP, and the miR-6325/LANCL1 axis may be involved in the occurrence and development of NeuP. Cascade reactions including mast cells, macrophages, and T cells may be an important reason for the aggravation of nerve damage.


Assuntos
MicroRNAs , Neuralgia , Biomarcadores , Bases de Dados Factuais , Humanos , Macrófagos , MicroRNAs/genética , Receptores Acoplados a Proteínas G
5.
Plant Cell Environ ; 44(2): 412-424, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33125160

RESUMO

The circadian clock allows plants to actively adapt to daily environmental changes through temporal regulation of physiological traits. In response to drought stress, circadian oscillators gate ABA signalling, but the molecular mechanisms remain unknown, especially in crops. Here, we investigated the role of soybean circadian oscillators GmLCLa1, GmLCLa2, GmLCLb1 and GmLCLb2 in leaf water stress response. Under dehydration stress, the GmLCL quadruple mutant had decreased leaf water loss. We found that the dehydration treatment delayed the peak expression of GmLCL genes by 4 hr. In addition, the circadian clock in hairy roots also responded to ABA, which led to a free-running rhythm with shortened period. Importantly, in the gmlclq quadruple mutant, diurnal expression phases of several circadian-regulated ABA receptor, ABA catabolism and ABA signalling-related genes were shifted significantly to daytime. Moreover, in the gmlclq mutant leaf, expression of GmPYL17, GmCYP707A, GmABI2 and GmSnRK2s was increased under water dehydration stress. In summary, our results show that GmLCLs act as negative regulators of ABA signalling in leaves during dehydration response.


Assuntos
Ácido Abscísico/metabolismo , Relógios Circadianos , Regulação da Expressão Gênica de Plantas , Glycine max/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Desidratação , Secas , Mutação , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Glycine max/genética , Estresse Fisiológico , Água/metabolismo
6.
Microsc Microanal ; 26(3): 484-496, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32456721

RESUMO

In electron probe microanalysis or scanning electron microscopy, the Monte Carlo method is widely used for modeling electron transport within specimens and calculating X-ray spectra. For an accurate simulation, the calculation of secondary fluorescence (SF) is necessary, especially for samples with complex geometries. In this study, we developed a program, using a hybrid model that combines the Monte Carlo simulation with an analytical model, to perform SF correction for three-dimensional (3D) heterogeneous materials. The Monte Carlo simulation is performed using MC X-ray, a Monte Carlo program, to obtain the 3D primary X-ray distribution, which becomes the input of the analytical model. The voxel-based calculation of MC X-ray enables the model to be applicable to arbitrary samples. We demonstrate the derivation of the analytical model in detail and present the 3D X-ray distributions for both primary and secondary fluorescence to illustrate the capability of our program. Examples for non-diffusion couples and spherical inclusions inside matrices are shown. The results of our program are compared with experimental data from references and with results from other Monte Carlo codes. They are found to be in good agreement.

7.
Eye Contact Lens ; 46(3): 147-153, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31211720

RESUMO

PURPOSE: To investigate the prevalence and associations of myopic anisometropia in Chinese adults. METHODS: A total of 3,791 Chinese refractive surgery candidates with myopia (25.15±7.09 years old, Mean±SD) were recruited. All eyes underwent a standardized ophthalmological examination. Associations between myopic anisometropia and age, gender, spherical ametropia, astigmatism, and axial length (AL) were analyzed by means of the chi-squared test, nonparametric Kruskal-Wallis or Mann-Whitney test, binomial logistic regression analyses, and multivariate logistic regression analysis. RESULTS: The mean myopic anisometropic level was 0.96 D and prevalence of myopic anisometropia was 29.62% (defined as myopic anisometropia ≥1.00 D). The prevalence and severity of myopic anisometropia increased with age, larger interocular AL difference, and higher cylindrical power (all P<0.001). Myopic anisometropia showed a U-shaped correlation with spherical equivalent (SE) refractive error and V-shaped correlations with AL, J0 and J45. Myopic anisometropia was most strongly associated with interocular AL difference (P<0.001). CONCLUSIONS: Compared with previous reports, this study revealed an even higher prevalence of myopic anisometropia and showed a U-shaped correlation with SE and a V-shaped correlation with AL. These results indicate that the formation of myopic anisometropia could be related to neural control in the binocular AL growth balance. Further study is needed to clarify this presumption.


Assuntos
Anisometropia/epidemiologia , Povo Asiático/estatística & dados numéricos , Miopia/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Comprimento Axial do Olho/patologia , China/epidemiologia , Estudos Transversais , Estudos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Refração Ocular/fisiologia , Distribuição por Sexo , Acuidade Visual/fisiologia , Adulto Jovem
8.
Sensors (Basel) ; 20(21)2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33142931

RESUMO

Power efficiency is becoming a critical aspect of IoT devices. In this paper, we present a compact object-detection coprocessor with multiple cores for multi-scale/type classification. This coprocessor is capable to process scalable block size for multi-shape detection-window and can be compatible with the frame-image sizes up to 2048 × 2048 for multi-scale classification. A memory-reuse strategy that requires only one dual-port SRAM for storing the feature-vector of one-row blocks is developed to save memory usage. Eventually, a prototype platform is implemented on the Intel DE4 development board with the Stratix IV device. The power consumption of each core in FPGA is only 80.98 mW.

9.
Blood Purif ; 39(1-3): 37-44, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25660686

RESUMO

BACKGROUND/AIMS: Recently, ultrasound signals termed 'lung water comets' associated with pulmonary edema have been correlated with adverse clinical events in dialysis patients. These comets fluctuate substantially during the ultrasound exam highlighting the need for objective quantitative measurement methods. METHODS: We developed an image-processing algorithm for the detection and quantification of lung comets. Quantification measures included comet number (comet count) and the fraction of the ultrasound beams with comet findings (comet fraction). We used this algorithm in a pilot study in 20 stable dialysis outpatients to identify associations between ultrasound comets and clinical parameters including blood pressure (BP), percent blood volume reduction on dialysis (%BV), ejection fraction (EF), and ultrafiltration on dialysis (UF). RESULTS: Positive findings included associations with lung comet measurements with pre-dialysis Diastolic BP (r = 0.534, p = 0.015), subject age (r = -0.446, p = 0.049), and a combination of EF and end dialysis %BV reduction (r = -0.585, p = 0.028). Comet fraction and comet count were closely correlated due to the inherent relationship between these two metrics (r = 0.973, p < 0.001). Negative findings included ultrasound comets that did not change from beginning to end of dialysis (p = 0.756), and were not significantly correlated with single dialysis treatment UF (p = 0.522), subject body weight (p = 0.208), or BMI (p = 0.358). CONCLUSIONS: Ultrasound signal processing methods may help quantify lung ultrasound comets. Additional findings include algorithmic lung comet measurement that did not change significantly during single dialysis sessions in these stable outpatients, but were associated with cardiovascular and fluid status parameters.


Assuntos
Edema Pulmonar/diagnóstico por imagem , Diálise Renal , Insuficiência Renal Crônica/terapia , Adulto , Idoso , Algoritmos , Pressão Sanguínea , Volume Sanguíneo , Feminino , Humanos , Rim/metabolismo , Rim/patologia , Pulmão/diagnóstico por imagem , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Edema Pulmonar/diagnóstico , Edema Pulmonar/patologia , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Volume Sistólico , Ultrafiltração/métodos , Ultrassonografia , Desequilíbrio Hidroeletrolítico
10.
Technol Health Care ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38820033

RESUMO

BACKGROUND: With the improvement of the level of science and technology, diagnosis and treatment technology of ophthalmology has continuously improved, especially with the rise of optical coherence tomography. Alternative methods have enabled clinicians to obtain more information and make greater breakthroughs in the occurrence and development of many ophthalmic diseases. OBJECTIVE: To investigate changes in retinal structure in the macular area of senile diabetic cataract patients undergoing cataract phacoemulsification. METHODS: This was a prospective cohort study. A total of 68 cataract patients (78 eyes) who voluntarily received phacoemulsification combined with intraocular lens implantation in the Department of Ophthalmology of our hospital from December 2018 to December 2021 were selected. They were divided into A (diabetic) and B (non-diabetic) according to whether they were complicated with diabetes. There were 24 cases (28 eyes) in A and 44 cases (50 eyes) in B. Cataract patients were collected before and after surgery. Day, 1 week, and 1 month, data on the average thickness of the fovea retina and thickness of the retinal nerve fiber layer around the optic disc (average thickness, nasal thickness, topic side thickness, upper thickness, and lower thickness) were statistically analyzed analyze. RESULTS: The average retinal thickness of the macular fovea in Group A was found to be greater than that of Group B, however, there was no statistically significant difference between the two groups. At week one and week thirty, Group A's layer of retinal nerve fibers surrounding the optic disc thickened; there was no discernible difference between the two groups. One week and one month following surgery, however, showed a one-week difference in upper thickness compared to preoperative days. There was no discernible change between the preoperative and 1-day times. CONCLUSION: Both diabetic cataract patients and simple age-related cataract patients will have different degrees of increased foveal retinal thickness after surgery. However, the foveal retinal thickness of patients with diabetes increases more.

11.
ACS Omega ; 9(23): 25146-25161, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38882111

RESUMO

The adsorption of CO2 by coal leads to changes in its mechanical properties, particularly when considering supercritical CO2 and water with supercritical CO2 adsorption. This is strongly linked to the efficiency of CO2-enhanced coalbed methane (CO2-ECBM) extraction and the safety of CO2 geological storage. This study focuses on 3# coal from the Datong Mine in Gaoping City, Shanxi Province. The high-rank coal's mechanical properties, including the triaxial compressive strength and elastic modulus, were examined under the combined effects of CO2 injection pressure, CO2 injection time, and moisture content. The triaxial compressive strength and elastic modulus of the coal showed a decrease following CO2 injection. Increasing the CO2 injection pressure, prolonging the CO2 injection time, and increasing the moisture content were favorable for coal softening. In particular, the triaxial compressive strength and elastic modulus of the coal sample after 144 h of water and supercritical CO2 softening decreased by 67.67 and 64.15%, respectively. Injecting CO2 into coal changed its failure mode. The dry raw coal sample exhibited a brittle shear failure mode, while the coal samples showed transitional shear failure after injecting 6 MPa CO2 and 8 MPa CO2 and ductile nondilatant barreling failure after injecting water and 8 MPa CO2 (with a moisture content of 3.02%). Moreover, the cumulative acoustic emission energy of the coal samples followed a similar trend to the decrease in mechanical properties under different conditions. The physical and chemical interactions among coal, CO2, and water caused the softening of coal; these included the generation of the swelling stress, the dissolution of minerals by carbonate solutions, the reduction in surface energy of coal owing to CO2 adsorption, and the extraction and plasticization reactions of organic matter in coal. The research results are of great significance for further understanding CO2-ECBM and CO2 geological sequestration.

12.
J Affect Disord ; 362: 459-467, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39013522

RESUMO

BACKGROUND: Chronic pain and depression share common neural mechanisms, but their impacts on empathy are different. It is unclear how comorbid depressive symptoms affect empathy-related brain function in patients with chronic pain. METHODS: A total of 29 healthy participants and 107 patients with chronic back pain (CBP) were included in this study. All subjects underwent a functional MRI scan with concurrent empathic stimulation. Multiple linear regression, moderation analysis, and mediation analysis were used to explore the impacts of chronic pain and comorbid depression on empathy. RESULTS: The interaction between the pain intensity and the depressive symptoms affected the functional connectivity (FC) of the insula-middle frontal gyrus (MFG), and the severity of the self-rating depression scale (SDS) scores moderated the effect of the pain on the left insula-left MFG FC. Within the CBP group, the emotional contagion (EC) scores served as a mediator in the association between the SDS scores and the FC of the left middle cingulate cortex (MCC)-inferior temporal gyrus (ITG), and the level of cognitive empathy (CE) moderated the effect of the SDS scores on the left MCC-ITG FC. LIMITATIONS: There is a lack of research on the effects of depressive symptoms on empathy in individuals with different types of chronic pain. CONCLUSION: Depressive symptoms were strongly associated with the emotional contagion in patients with chronic back pain. Furthermore, the emotional contagion and the cognitive empathy regulated the effect of the comorbid depressive symptoms on the MCC-ITG connectivity in patients with chronic back pain.

13.
Cancer Biother Radiopharm ; 38(10): 674-683, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32907351

RESUMO

Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer. Circular RNAs (circRNAs) play a vital role in cancer development and progression. This study investigated the role and potential mechanism of circRNA filamin binding LIM protein 1 (circFBLIM1) in HCC. Methods: Exosomes were identified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot assay. The levels of circFBLIM1, miR-338, and low-density lipoprotein receptor-related protein 6 (LRP6) were measured by quantitative real-time polymerase chain reaction or Western blot. Glycolysis was analyzed by detecting glucose consumption, lactate production, ATP level, extracellular acidification rate (ECAR), and oxygen consumption rate (OCR). Cell viability was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis was detected by flow cytometry. Xenograft assay was performed to analyze tumor growth in vivo. The interaction among circFBLIM1, miR-338, and LRP6 was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. This study was approved by the Institutional Review Board of the First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine. Results: CircFBLIM1 was highly expressed in HCC serum exosomes and HCC cells. Inhibition of circFBLIM1 confined HCC glycolysis and progression. CircFBLIM1 knockdown blocked tumorigenesis in vivo. CircFBLIM1 was a sponge of miR-338 and promoted HCC progression and glycolysis by regulating miR-338. Moreover, miR-338 suppressed HCC progression and glycolysis via targeting LRP6. Mechanistically, circFBLIM1 functioned as an miR-338 sponge to upregulate LRP6. Conclusion: CircFBLIM1 facilitated HCC progression and glycolysis via modulating the miR-338/LRP6 axis, which may provide promising therapeutic targets for HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Apoptose , MicroRNAs/genética , Proliferação de Células , Linhagem Celular Tumoral , Glicólise
14.
Micromachines (Basel) ; 14(8)2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37630027

RESUMO

In this research, an efficient thermal-stress coupling design method for a Chiplet-based system with a coaxial through silicon via (CTSV) array is developed by combining the support vector machine (SVM) model and particle swarm optimization algorithm with linear decreasing inertia weight (PSO-LDIW). The complex and irregular relationship between the structural parameters and critical indexes is analyzed by finite element simulation. According to the simulation data, the SVM model is adopted to characterize the relationship between structural parameters and critical indexes of the CTSV array. Based on the desired critical indexes of the CTSV array, the multi-objective evaluation function is established. Afterwards, the structural parameters of the CTSV array are optimized through the PSO-LDIW algorithm. Finally, the effectiveness of the developed method is verified by the finite element simulation. The simulated peak temperature, peak stress of the Chiplet-based system, and peak stress of the copper column (306.16 K, 28.48 MPa, and 25.76 MPa) well agree with the desired targets (310 K, 30 MPa, and 25 MPa). Therefore, the developed thermal-stress coupling design method can effectively design CTSV arrays for manufacturing high-performance interconnect structures applied in Chiplet-based systems.

15.
Materials (Basel) ; 16(7)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37049002

RESUMO

Due to their light weight and outstanding mechanical properties at high temperatures, Ti3Al-based intermetallic alloys have driven increasing interest from both academia and industry; however, when additive manufacturing (AM) is applied to them, the outcome is hardly satisfying. In this work, we report a crack-free Ti3Al-based alloy fabrication by laser powder bed fusion (LPBF) using a mixture of a commercial Ti-48Al-2Cr-2Nb powder and a pure Ti powder. With the aid of a high cooling rate during LPBF, the as-built sample shows a ductile ß phase with some partially-melted particles. After the heat treatment, partially-melted particles were dissolved, and the sample showed equiaxed α2 precipitates in the ß matrix. The hardness was 515 ± 38 HV in the as-built sample and 475 ± 37 HV in the heat-treated sample. This study shows a novel strategy to fabricate crack-free Ti3Al-based alloy using LPBF from powder blends.

16.
Artigo em Inglês | MEDLINE | ID: mdl-38083445

RESUMO

Labeled ECG data in diseased state are, however, relatively scarce due to various concerns including patient privacy and low prevalence. We propose the first study in its kind that synthesizes atrial fibrillation (AF)-like ECG signals from normal ECG signals using the AFE-GAN, a generative adversarial network. Our AFE-GAN adjusts both beat morphology and rhythm variability when generating the atrial fibrillation-like ECG signals. Two publicly available arrhythmia detectors classified 72.4% and 77.2% of our generated signals as AF in a four-class (normal, AF, other abnormal, noisy) classification. This work shows the feasibility to synthesize abnormal ECG signals from normal ECG signals.Clinical significance - The AF ECG signal generated with our AFE-GAN has the potential to be used as training materials for health practitioners or be used as class-balance supplements for training automatic AF detectors.


Assuntos
Fibrilação Atrial , Humanos , Fibrilação Atrial/diagnóstico , Eletrocardiografia , Doença do Sistema de Condução Cardíaco
17.
Micromachines (Basel) ; 14(10)2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37893328

RESUMO

In this research, a high-efficiency design method of the capacitive MEMS accelerometer is proposed. As the MEMS accelerometer has high precision and a compact structure, much research has been carried out, which mainly focused on the structural design and materials selection. To overcome the inconvenience and inaccuracy of the traditional design method, an orthogonal design and the particle swarm optimization (PSO) algorithm are introduced to improve the design efficiency. The whole process includes a finite element method (FEM) simulation, high-efficiency design, and verification. Through the theoretical analysis, the working mechanism of capacitive MEMS accelerometer is clear. Based on the comparison among the sweep calculation results of these parameters in the FEM software, four representative structural parameters are selected for further study, and they are le, nf, lf and wPM, respectively. le and lf are the length of the sensing electrode and fixed electrode on the right. nf is the number of electrode pairs, and wPM is the width of the mass block. Then, in order to reduce computation, an orthogonal design is adopted and finally, 81 experimental groups are produced. Sensitivity SV and mass Ma are defined as evaluation parameters, and structural parameters of experimental groups are imported into the FEM software to obtain the corresponding calculation results. These simulation data are imported into neural networks with the PSO algorithm. For a comprehensively accurate examination, three cases are used to verify our design method, and every case endows the performance parameters with different weights and expected values. The corresponding structural parameters of each case are given out after 24 iterations. Finally, the maximum calculation errors of SV and Ma are 1.2941% and 0.1335%, respectively, proving the feasibility of the high-efficiency design method.

18.
Brain Res ; 1818: 148473, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37414269

RESUMO

Fear generalization contributes to the development and maintenance of pain. Pain sensitivity has been proposed to predict the strength of fear responses to aversive stimuli. However, whether individual variation in pain sensitivity affects pain-related fear generalization and its underlying cognitive processing remains unclear. To address this gap, we recorded behavioral and event-related potential (ERP) data among 22 high pain sensitivity (HPS) and 22 low pain sensitivity (LPS) healthy adults when exposed to a fear generalization paradigm. The behavioral results indicate that the HPS group displayed higher unconditioned stimulus expectancy and greater fear, arousal, and anxiety ratings to conditioned stimulus and generalization stimulus than the LPS group (all p values < 0.05). The ERP results showed that the HPS group exhibited a larger late positive potential evoked by GS2, GS3 and CS- (all p < 0.005) but a smaller N1 evoked by all CS and GSs (all p values < 0.05) relative to the LPS group. These findings suggest that individuals with a high level of pain sensitivity allocate more attention resources to pain-related threatening stimuli, which contributes to an overgeneralization of pain-related fear.


Assuntos
Medo , Lipopolissacarídeos , Adulto , Humanos , Medo/fisiologia , Cognição , Dor , Potenciais Evocados
19.
Brain Behav ; 13(7): e3050, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37132353

RESUMO

INTRODUCTION: Excessiv generalization of fear contributes to the development and maintenance of pain. Prior research has demonstrated the importance of perception in fear generalization and found that individuals in painful conditions exhibited perceptual bias. However, the extent to which perceptual bias in pain affects the generalization of pain-related fear and its underlying neural activity remains unclear. METHODS: Here, we tested whether perceptual bias in experimental pain individuals led to the overgeneralization of pain-related fear by recording behavioral and neural responses. To this end, we established an experimental pain model by spraying capsaicin on the surface of the seventh cervical vertebra of the participant. A total of 23 experimental pain participants and 23 matched nonpain controls learned fear conditioning and then completed the fear generalization paradigm combined with the perceptual categorization task. RESULTS: We found that the novel and safety cues were more likely to be identified as threat cues in the experimental group, resulting in higher US expectancy ratings compared to the control group. The event-related potential results showed that the experimental group exhibited earlier N1 latency and smaller P1 and late positive potential amplitudes than those in the control group. CONCLUSION: Our findings suggest that the experimental pain individuals exhibited an excessive generalization of fear affected by perceptual bias and reduced their attentional allocation to pain-related fear stimuli.


Assuntos
Condicionamento Clássico , Medo , Humanos , Condicionamento Clássico/fisiologia , Medo/fisiologia , Generalização Psicológica/fisiologia , Dor , Potenciais Evocados
20.
ACS Omega ; 7(19): 16728-16739, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35601307

RESUMO

It is important to explore the changes in coal pores in response to triaxial compression and shear deformation for coal mine gas drainage and efficient coalbed methane mining. To study the variation in coal pores depending on stress, first, a mechanical analysis was carried out, and then the characteristics of coal samples before and after triaxial compression were quantitatively analyzed combined with low-temperature nitrogen adsorption experiments. The compressive strength of the coal samples with a high elastic modulus is significantly greater than that of coal samples with a low elastic modulus. Sihe coal samples with a larger elastic modulus experienced higher peak stress and strain during compression than those from the Chengzhuang Mine with a smaller elastic modulus. With the exception of the coal sample from the Chengzhuang Mine with a confining pressure of 15 MPa, the peak strength and axial strain of the coal samples gradually increased with an increase in confining pressure. The larger the elastic modulus, the greater the axial strain. After triaxial compression, pores with diameters ranging from 2 to 5 nm exhibited a significant change. After the compression of coal with a high elastic modulus, the pore volume and pore specific surface area decreased with the increase in confining pressure, by 60.7 and 59.7%, respectively (compared with raw coal). The complex pore structure consisting of mesopores and macropores (>11 nm) became simpler. The volume and specific surface area of the pores of the coal samples with a low elastic modulus first increased, then decreased, and then increased again with the increase in confining pressure, and after compression, the roughness and complexity of macropores of coal samples are greater than those of micropores. The changes induced in the coal samples of the two mining areas in response to compression differ, which are related to the mechanical properties of the coal bodies.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA