Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 485
Filtrar
1.
Chinese Pharmacological Bulletin ; (12): 6-12, 2024.
Artigo em Chinês | WPRIM | ID: wpr-1013600

RESUMO

Chronic obstructive pulmonary disease ( COPD ) major chronic disease threatening public health with complex pathological mechanisms. The change of the cell microenvironment of the lung is an important part of the pathophysiology of COPD. Cell culture technology is an important method to investigate the pathological mechanism of COPD and evaluate the pharmacological effect of medicine. Here we introduce the composition of the cell microenvironment of the lung, the change of the cell microenvironment in the pathological process of COPD, and summarize the application of in vitro model mimics cell microenvironment of COPD in the study of mechanism. In addition, we aim to put forward the ideas of the in vitro model establishment of cell microenvironment of COPD.

2.
Chinese Journal of Rehabilitation Theory and Practice ; (12): 202-209, 2024.
Artigo em Chinês | WPRIM | ID: wpr-1013378

RESUMO

ObjectiveTo explore the effect of brain-computer interface (BCI) based on visual, auditory and motor feedback combined with transcranial direct current stimulation (tDCS) on upper limb function in stroke patients. MethodsFrom March to October, 2023, 45 stroke inpatients in Xuzhou Rehabilitation Hospital and Xuzhou Central Hospital were divided into BCI group (n = 15), tDCS group (n = 15) and combined group (n = 15) randomly. All the groups received routine rehabilitation, while BCI group received BCI training, tDCS group received tDCS, while the combined group received tDCS and followed by BCI training immediately, for four weeks. They were assessed with Fugl-Meyer Assessment-Upper Extremities (FMA-UE), Action Research Arm Test (ARAT), modified Barthel Index (MBI) and delta-alpha ratio (DAR) and power ratio index (PRI) of electroencephalogram before and after treatment. ResultsThe scores of FMA-UE, ARAT and MBI increased in all the groups after treatment (|t| > 5.350, P < 0.001), and all these indexes were the best in the combined group (F > 3.366, P < 0.05); while DAR and PRI decreased in all the groups (|t| > 2.208 , P < 0.05), they were the best in the combined group (F > 5.224, P < 0.01). ConclusionBCI based on visual, auditory and motor feedback combined with tDCS can further improve the motor function of upper limbs and the activities of daily living of stroke patients.

3.
São José dos Campos; s.n; 2024. 86 p. ilus, tab.
Tese em Português | LILACS, BBO | ID: biblio-1551231

RESUMO

A eficácia dos implantes osseointegrados é amplamente reconhecida na literatura científica. Contudo, infiltrações bacterianas na junção implante-pilar podem desencadear inflamação nos tecidos circundantes, contribuindo para a evolução de condições mais sérias, como a peri-implantite. O objetivo desse estudo foi produzir complexos polieletrólitos (PECs) de quitosana (Q) e xantana (X) em forma de membranas, carregá-las com ativos naturais e sintéticos antimicrobianos, caracterizálas estruturalmente e avaliá-las frente a degradação enzimática, cinética de liberação e ações antimicrobianas com finalidade de aplicação para drug delivery. Membranas de QX a 1% (m/v) foram produzidas em três proporções, totalizando doze grupos experimentais: QX (1:1); QX (1:2), QX (2:1), QX-P (com própolis) (1:1); QX-P (1:2); QX-P (2:1); QX-C (com canela) (1:1); QX-C (1:2); QX-C (2:1) e CLX (com clorexidina 0,2%) (1:1); CLX (1:2); CLX (2:1). Para os estudos de caracterização foram feitas análises da espessura em estado seco; análises morfológicas superficial e transversal em Microscopia Eletrônica de Varredura (MEV); análise estrutural de espectroscopia de infravermelho por transformada de Fourier (FTIR); análise de degradação por perda de massa sob ação da enzima lisozima; e análise da cinética de liberação dos ativos em saliva artificial. Para os testes microbiológicos, análises de verificação de halo de inibição e ação antibiofilme foram feitas contra cepas de Staphylococcus aureus (S. aureus) e Escherichia coli (E. coli). Os resultados demonstraram que a espessura das membranas variou conforme a proporção, sendo que o grupo QX (1:2) apresentou a maior média de 1,022 mm ± 0,2, seguida respectivamente do QX (1:1) com 0,641 mm ± 0,1 e QX (2:1) com 0,249 mm ± 0,1. Nas imagens de MEV é possível observar uma maior presença de fibras, rugosidade e porosidade nos grupos QX (1:2) e QX (1:1) respectivamente, e, no QX (2:1) uma superfície mais lisa, uniforme e fina. No FTIR foram confirmados os picos característicos dos materiais isoladamente, além de observar as ligações iônicas que ocorreram para formação dos PECs. Na análise de degradação, os grupos com ativos naturais adicionados tiveram melhores taxas de sobrevida do que os grupos QX. No teste de liberação, os grupos QX-P tiveram uma cinética mais lenta que os QX-C, cuja liberação acumulada de 100% foi feita em 24 h. Já nos testes do halo inibitório, somente os grupos CLX tiveram ação sobre as duas cepas, e os QX-P tiveram sobre S. aureus. Nas análises antibiofilme, os grupos CLX apresentaram as maiores taxas de redução metabólica nas duas cepas (± 79%); os grupos QX-P apresentaram taxas de redução similares em ambas as cepas, porém com percentual um pouco maior para E. coli (60- 80%) e os grupos QX-C tiveram grande discrepância entre as duas cepas: de 35 a 70% para S. aureus e 14 a 19% para E. coli. Pode-se concluir que, frente as análises feitas, o comportamento do material foi afetado diretamente pelos ativos adicionados a matriz polimérica. As proporções de Q ou X afetaram somente a espessura final. Quanto a aplicação proposta de drug delivery, os dispositivos apresentaram grande potencial, principalmente os grupos CLX e QX-P. (AU)


The effectiveness of osseointegrated implants is widely recognized in scientific literature. However, bacterial infiltrations at the implant-abutment interface may trigger inflammation in surrounding tissues, contributing to the development of more serious conditions, such as peri-implantitis. The aim of this study was to produce chitosan (Q) and xanthan (X) polyelectrolyte complexes (PECs) in the form of membranes, load and evaluate them for enzymatic degradation, release kinetics, and antimicrobial actions for drug delivery applications. QX membranes at 1% (w/v) were produced in three proportions, totaling twelve experimental groups: QX (1:1), QX (1:2), QX (2:1), QX-P (with propolis) (1:1), QX-P (1:2), QX-P (2:1), QX-C (with cinnamon) (1:1), QX-C (1:2), QX-C (2:1), and CLX (with 0.2% chlorhexidine) (1:1), CLX (1:2), CLX (2:1). Characterization studies included analyses of dry state thickness, surface and crosssectional morphology using Scanning Electron Microscopy (SEM), structural analysis by Fourier Transform Infrared (FTIR) spectroscopy, mass loss degradation analysis under lysozyme action, and active release kinetics analysis in artificial saliva. Microbiological tests included verification analyses of inhibition halos and antibiofilm action against strains of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Results showed that membrane thickness varied according to proportion, with group QX (1:2) presenting the highest average of 1.022 mm ± 0.2, followed by QX (1:1) with 0.641 mm ± 0.1, and QX (2:1) with 0.249 mm ± 0.1. SEM images showed greater presence of fibers, roughness, and porosity in groups QX (1:2) and QX (1:1) respectively, while QX (2:1) exhibited a smoother, more uniform, and thinner surface. FTIR confirmed characteristic peaks of the materials individually, besides showing ionic bonds formed for PECs. Degradation analysis revealed that groups with added natural actives had better survival rates than QX groups. In release tests, QX-P groups exhibited slower kinetics than QX-C, with 100% cumulative release achieved in 24 h. inhibitory halo tests, only CLX groups exhibited action against both strains, while QX-P acted against S. aureus. Antibiofilm analyses showed CLX groups with the highest metabolic reduction rates in both strains (± 79%); QX-P groups showed similar reduction rates in both strains, slightly higher for E. coli (60-80%), and QX-C groups had a significant discrepancy between strains: 35-70% for S. aureus and 14-19% for E. coli. In conclusion, material behavior was directly affected by added actives to the polymeric matrix. Proportions of Q or X only affected final thickness. Regarding proposed drug delivery applications, the devices showed great potential, especially CLX and QX-P groups.(AU)


Assuntos
Sistemas de Liberação de Medicamentos , Quitosana , Projeto do Implante Dentário-Pivô , Compostos Fitoquímicos , Polieletrólitos
4.
Artigo | IMSEAR | ID: sea-225563

RESUMO

Background: The brain-computer interface (BCI) is gaining much attention to treat neurological disorders and improve brain-dependent functions. Significant achievements over the last decade have focused on engineering and computation technology to enhance the recording of signals and the generation of output stimuli. Nevertheless, many challenges remain for the translation of BCIs to clinical applications. Methods: We review the relevant data on the four significant gaps in enhancing BCI's clinical implementation and effectiveness. Results: The paper describes three methods to bridge the current gaps in the clinical application of BCI. The first is using a brain-directed adjuvant with a high safety profile, which can improve the accuracy of brain signaling, summing of information, and production of stimuli. The second is implementing a second-generation artificial intelligence system that is outcome-oriented for improving data streaming, recording individualized brain-variability patterns into the algorithm, and improving closed-loop learning at the level of the brain and with the target organ. The system overcomes the compensatory mechanisms that underlie the loss of stimuli' effectiveness for ensuring sustainable effects. Finally, we use inherent brain parameters relevant to consciousness and brain function to bridge some of the described gaps. Conclusions: Combined with the currently developed techniques for enhancing effectiveness and ensuring a sustainable response, these methods can potentially improve the clinical outcome of BCI techniques.

5.
Braz. dent. j ; 34(3): 66-72, May-June 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, BBO | ID: biblio-1447593

RESUMO

Abstract The aim of this study was to evaluate the osseointegration of a hydrophilic surface (blasting + acid etching + immersion in isotonic solution) in comparison with that of a control surface (blasting + acid etching) using an experimental model of low-density bone. To perform the study, 24 rabbits were submitted to the installation of 4 implants in the iliac bone bilaterally: 2 implants with a control surface and 2 implants with a hydrophilic surface. The rabbits were euthanized at 2, 4, and 8 weeks after implant installation. After euthanasia, one implant from each surface was used to perform the removal torque analysis, and the other implant was used for the execution of non-decalcified histological sections and evaluation of the bone implant contact (% BIC) as well as the fraction of bone tissue area between the implant threads (% BBT). The implants with a hydrophilic surface presented higher %BIC (42.92 ± 2.85% vs. 29.49 ± 10.27%) and % BBT (34.32 ± 8.52% vs. 23.20 ± 6.75%) (p < 0.05) in the 2-week period. Furthermore, the hydrophilic surface presented higher removal torque in the 8-week period (76.13 ± 16.00 Ncm2 vs. 52.77 ± 13.49 Ncm2) (p<0.05). Implants with a hydrophilic surface exhibited acceleration in the process of osseointegration, culminating in greater secondary stability in low-density bone than in implants with a control surface.


Resumo O objetivo deste estudo foi avaliar a osseointegração de uma superfície hidrofílica (jateamento + ataque ácido + imersão em solução isotônica) em comparação com uma superfície controle (jateamento + ataque ácido) usando um modelo experimental de osso de baixa densidade. Para realizar o estudo, 24 coelhos foram submetidos a instalação de 4 implantes bilateralmente no osso ilíaco: 2 implantes com superfície controle e 2 implantes com superfície hidrofílica. Os coelhos foram eutanasiados com 2, 4 e 8 semanas após a instalação dos implantes. Após a eutanásia, um implante de cada superfície foi usado para avaliar o torque de remoção, e o outro implante foi utilizado para execução de cortes histológicos não descalcificados e avaliação de contato osso implante (% BIC) bem como a fração da área tecido ósseo entre as roscas do implante (% BBT). Os implantes com superfície hidrofílica apresentaram maior %BIC (42.92 ± 2.85% vs. 29.49 ± 10.27%) e % BBT (34.32 ± 8.52% vs. 23.20 ± 6.75%) (p < 0.05) no período de 2 semanas. Além disso, a superfície hidrofílica apresentou maior torque de remoção no período de 8 semana (76.13 ± 16.00 Ncm2 vs. 52.77 ± 13.49 Ncm2) (p<0.05). Implantes com a superfície hidrofílica apresentaram aceleração no processo de osseointregração, culminando em melhor estabilidade secundária no osso de baixa densidade em relação a implantes com superfície controle.

6.
Rev. Psicol., Divers. Saúde ; 12(1)fev. 2023. tab, ilus
Artigo em Espanhol, Português | LILACS | ID: biblio-1451185

RESUMO

INTRODUÇÃO: Família e trabalho configuram-se como domínios que auxiliam na compreensão do comportamento do indivíduo de forma coletiva e individual. A pandemia da COVID-19 e a adesão ao home office tornaram relevante pensar nas interfaces estabelecidas entre trabalho-família e, também, no papel dos gestores organizacionais nessa relação. OBJETIVO: Identificar como teletrabalhadores e profissionais de gestão de pessoas/saúde ocupacional (GP/SO) têm percebido as interfaces entre trabalho-família em tempos de pandemia da COVID-19. METODOLOGIA: O trabalho foi composto por dois estudos complementares: uma revisão de literatura e uma pesquisa empírica sobre a percepção de profissionais de gestão de pessoas/saúde ocupacional. Para a revisão, buscas nas bases eletrônicas Scielo, Pepsic e Lilacs foram realizadas, sendo selecionados artigos científicos que abordassem o equilíbrio entre trabalho e família durante a pandemia da Covid-19. Para a pesquisa empírica, participaram do estudo 38 profissionais de GP/SO, que responderam a um questionário online. As respostas foram analisadas por meio da análise de conteúdo temática. RESULTADOS: Identificou-se na visão dos teletrabalhadores, mudanças na dinâmica trabalho-família, dificuldades financeiras, necessidade de usar novas tecnologias para a realizar o trabalho, prejuízos à saúde mental, questões relacionadas a gênero e possíveis estratégias de enfrentamento. Na visão da GP/SO, os trabalhadores tiveram dificuldade em conciliar trabalho-família. A falta de equipamentos e ambiente adequados influenciaram de forma negativa na produtividade. CONCLUSÃO: Acredita-se que o cenário pandêmico, associado ao aumento da jornada de trabalho e à cobrança excessiva por produtividade, tenha elevado o nível de tensão/estresse entre os indivíduos, gerando desequilíbrio entre as esferas familiar e ocupacional.


INTRODUCTION: Family and work are configured as domains that help in understanding the individual's behavior collectively and individually. The COVID-19 pandemic and remote work adherence made it relevant to think about the interfaces established between family work and also on the role of organizational managers in this relationship OBJECTIVE: To identify how teleworkers and people management/ occupational health professionals (PM/OHP) have perceived the interfaces between work and family during the COVID-19 pandemic. METHODOLOGY: The present work consisted of two complementary studies: a literature review and one empirical research about the perception of PM/OHP regarding the same phenomenon. For the review, searches were performed in the Scielo, Pepsic, and Lilacs electronic databases, and scientific articles that addressed the balance between work and family during the COVID-19 pandemic. For the empirical research, 38 PM/OHP participated in the study, and answered an online questionnaire. The answers were analyzed using thematic content analysis. RESULTS: It was identified in the view of teleworkers, changes in work-family dynamics, financial difficulties, the need to use new technologies to perform work, damage to mental health, gender-related issues and possible coping strategies. In the PM/OHP view, workers had difficulty reconciling family and work. The lack of adequate equipment and environment negatively influenced productivity. CONCLUSION: It's believed that the pandemic scenario, associated with the increase in working hours and excessive demands for productivity, has increased the level of tension and stress among individuals, generating an imbalance in the family and occupational spheres.


INTRODUCCIÓN: La familia y el trabajo se configuran como dominios que ayudan a comprender el comportamiento del individuo de manera colectiva e individual. La pandemia de COVID-19 y la adhesión al home office hicieron relevante pensar en las interfaces establecidas entre el trabajo familiar y también en el papel de los gerentes organizacionales en esta relación OBJETIVO: Identificar cómo los teletrabajadores y los profesionales de la gestión de personas/salud ocupacional (PGP/SO) han percibido las interfaces entre el trabajo y la familia durante la pandemia de COVID-19. METODOLOGÍA: El presente trabajo consistió en dos estudios complementarios: una revisión bibliográfica y una investigación empírica sobre la percepción de PM/OHP respecto al mismo fenómeno. Para la revisión, se realizaron búsquedas en las bases de datos electrónicas Scielo, Pepsic y Lilacs, y artículos científicos que abordaron el equilibrio entre el trabajo y la familia durante la pandemia de COVID-19. Para la investigación empírica, 38 PGP/SO participaron en el estudio, quienes respondieron un cuestionario en línea. Las respuestas fueron analizadas mediante análisis de contenido temático. RESULTADOS: Se identificó, en vista de los teletrabajadores, cambios en la dinámica trabajo-familia, dificultades financieras, necesidad de utilizar nuevas tecnologías para realizar el trabajo, daños a la salud mental, cuestiones relacionadas con el género y posibles estrategias de afrontamiento. Desde el punto de vista de PGP/SO, los trabajadores tenían dificultades para conciliar el trabajo familiar. La falta de equipos y entornos adecuados influyó negativamente en la productividad. CONCLUSIÓN: Se cree que el escenario de pandemia, asociado al aumento de la jornada laboral y a las demandas excesivas de productividad, ha aumentado el nivel de tensión y estrés entre los individuos, generando un desequilibrio en los ámbitos familiar y ocupacional.


Assuntos
COVID-19 , Trabalho , Família
7.
Chinese Journal of Pharmacology and Toxicology ; (6): 553-553, 2023.
Artigo em Chinês | WPRIM | ID: wpr-992222

RESUMO

Neural recording electrodes enable the acquisition and collection of electrical signals from neu-rons,and these recorded neural electrical signals are an important means of understanding neuronal activity.As a major component of the brain-machine interface,neu-ral recording electrodes serve as a bridge between the nervous system and external devices.The extracted information can be used to understand the state of the brain and acts as a feedback signal to regulate external devices,thus providing important information for the clini-cal treatment of neurological diseases.Moreover,the electrodes can be used as a vehicle for drug injection to directly treat diseases.Since the time that Strumwas-ser used microwires to achieve long-term recordings of neural activity in hibernating squirrels,implantable elec-trode technology has gradually improved over three gen-erations of development,and progress has been made in improving the biocompatibility,mechanical performance(size,shape,density,etc.),and signal-to-noise ratio.Implantable neural recording electrodes can acquire sig-nals from cortical and deep neural clusters,with the advantages of high signal-to-noise ratio,information con-tent,and spatial/temporal resolution.However,there is still a need to improve the structure and performance of these electrodes;for example,their high invasiveness and lack of biocompatibility pose technical difficulties in the process of translation to the clinic.This paper reviews the basic requirements for electrodes,main recording methods and signal types,common types of implant-able neural recording electrodes,and their challenges and future development directions.With the continuous development of electrode materials,equipment,systems,and neurotechnology,it should be possible to apply neu-ral recording electrodes in clinical practice,to promote safe and efficient treatment of human diseases.

8.
Journal of Pharmaceutical Analysis ; (6): 216-222, 2023.
Artigo em Chinês | WPRIM | ID: wpr-991137

RESUMO

The direct coupling of solid-phase microextraction(SPME)to mass spectrometry(MS)(SPME-MS)has proven to be an effective method for the fast screening and quantitative analysis of compounds in complex matrices such as blood and plasma.In recent years,our lab has developed three novel SPME-MS techniques:SPME-microfluidic open interface-MS(SPME-MOI-MS),coated blade spray-MS(CBS-MS),and SPME-probe electrospray ionization-MS(SPME-PESI-MS).The fast and high-throughput nature of these SPME-MS technologies makes them attractive options for point-of-care analysis and anti-doping testing.However,all these three techniques utilize different SPME geometries and were tested with different MS instruments.Lack of comparative data makes it difficult to determine which of these methodologies is the best option for any given application.This work fills this gap by making a comprehensive comparison of these three technologies with different SPME devices including SPME fibers,CBS blades,and SPME-PESI probes and SPME-liquid chromatography-MS(SPME-LC-MS)for the analysis of drugs of abuse using the same MS instrument.Furthermore,for the first time,we developed different desorption chambers for MOI-MS for coupling with SPME fibers,CBS blades,and SPME-PESI probes,thus illustrating the universality of this approach.In total,eight analytical methods were developed,with the experimental data showing that all the SPME-based methods provided good analytical performance with R2 of linearities larger than 0.9925,accuracies between 81%and 118%,and good precision with an RSD%≤13%.

9.
International Journal of Biomedical Engineering ; (6): 288-299, 2023.
Artigo em Chinês | WPRIM | ID: wpr-989353

RESUMO

Objective:To improve the users’ comfort of steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) through high-frequency stimulation and overcome the problem of accuracy decline caused by high frequency by combining dual-frequency encoding.Methods:Two dual-frequency high-frequency 60-instruction paradigms based on left and right visual fields and checkerboard stimuli were designed based on the 25.5 - 39.6 Hz frequency. Thirteen subjects participated in the experiment, and spectrum and spatial characteristics analyses were performed on SSVEP signals. The filter bank parameters were optimized based on the spectrum characteristics. Extended canonical correlation analysis (eCCA), ensemble task-related component analysis (eTRCA), and task-discriminant component analysis (TDCA) were used for SSVEP recognition.Results:Stable SSVEP was successfully induced in both the left and right visual fields and the checkerboard grid paradigm. The left and right visual fields had high signal-to-noise ratios for the fundamental frequency and its harmonics and weak signal-to-noise ratios for intermodulation components, whereas the intermodulation components of the 2 stimulus frequencies of the checkerboard grid, f1 + f2, had significantly higher signal-to-noise ratios than the second harmonic components above 30 Hz, and there was also a f2 ? f1 component and a 2 f1 ? f2 component. Combined with brain topography, it can be seen that the f1 and f2 response components of the left and right visual fields are located on opposite sides of the visual field, while the checkerboard grids are both concentrated in the center of the occipital region. Regarding the lateralization of brain topography amplitude and signal-to-noise ratio, the mean values of the PO3 and PO4 signal-to-noise ratios at the stimulation frequency of the left and right visual fields are consistent with the contralateral response characteristics. The 5 fb ? 1 method is the optimal filter set setting method, and the recognition correctness rate of TDCA for the left and right visual fields is the highest. However, the comparison of the recognition correctness rate of tessellated lattice eTRCA and TDCA is not statistically significant ( P > 0.05). The information transmission rates of the three algorithms all increase and then decrease with the increase in data length. Conclusions:The designed dual-frequency, high-frequency SSVEP-BCI paradigm is able to better balance performance and comfort and provides a basis for practical large instruction set BCI design methods.

10.
Journal of Medical Biomechanics ; (6): E528-E534, 2023.
Artigo em Chinês | WPRIM | ID: wpr-987981

RESUMO

Objective To improve the performance of artificial joint at biological fixed interface by frettingmechanical stimulation. Methods Taking the bonding sample of active rat bone tissues and inactive titanium bead coating as the research object, by using the self-developed fretting mechanical stimulation test device, the effects of mechanical stimulation with different tangential fretting amplitudes on growth promotion and micro-injury of bone tissues at fixed interface were explored, and the mechanism of growth promotion and micro-injury of bonetissues on the surface of titanium bead coating under fretting stimulation was revealed. Results The mechanical stimulation group with 40 μm fretting amplitude showed the maximum interface bonding force between bone tissues and titanium bead coating. The tangential fraction force-displacement curves changed from elliptic shape to linear shape, and the bonding interface was in adhesion area, which was difficult to become loose. The bone tissues had the most complete structure, and the number of tissue cells adhering and growing on the surface of titanium bead coating was the largest, as well as the distribution range was the widest. With the increase of fretting amplitude, the promoting effect of fretting stimulation on bone growth weakened, the bonding strength between bone tissues and titanium bead coating interface gradually decreased, the internal cavity area increased, the number and proliferation activity of tissue cells decreased to varying degrees as well. Conclusions Fretting stimulation with different amplitudes can promote the growth of bone tissue and cause micro-injury at the same time, and the optimal fretting amplitude is 40 μm.

11.
Journal of Medical Biomechanics ; (6): E479-E486, 2023.
Artigo em Chinês | WPRIM | ID: wpr-987974

RESUMO

Objective Based on interface damage, a numerical simulation method for in-plane propagation of false lumen (FL) was proposed to explore the regular pattern of in-plane propagation of the initial cavity. Methods Three interface damage modes were characterized by bi-linear traction separation law, and the damage parameters were calibrated by simulating peeling and shearing tests. The damage interface was introduced into the ideal double-layer cylindrical tube aortic model by means of cohesive zone model (CZM) to simulate the in-plane propagation of FL. The control variable method was used to establish several computational models to investigate the influence of cavity geometric parameters on propagation direction, critical pressure and interface damage mode. Results The interface damage was mainly opening mode (Mode I) in axial propagation and sliding mode (Mode II) in circumferential propagation. With radial depth of the initial cavity increasing, the propagation of the FL changed from circumferential direction to axial direction, the critical pressure decreased, and the axial damage tended to be pure opening mode. With circumferential angle and axial length of the initial cavity increasing, the critical pressure decreased and the circumferential damage tended to be pure sliding mode. The critical pressure of single damage was lower than that of mixed damage. Conclusions The CZM can effectively characterize interface damage behavior of elastic lamellae within the media, and it applies to numerical simulation of in-plane propagation of the FL. The results of this study is helpful to understand the complex pathophysiological process of dissection crack propagation.

12.
Chinese Journal of Orthopaedics ; (12): 991-998, 2023.
Artigo em Chinês | WPRIM | ID: wpr-993531

RESUMO

Regeneration of rotator cuff tendon-bone interface is crucial in rotator cuff repair. The tendon-bone interface consists of four continuous and gradual regions: the tendon region, the unmineralized fibrocartilage region, the mineralized fibrocartilage region, and the bone region. The development and regeneration of various regions in the tendon-bone interface is regulated by growth factors, inorganic ions, mechanical stimulation, and hypoxic environment. Inspired by factors affecting the development and regeneration of the tendon-bone interface, many researchers have designed gradient scaffold systems that promote regionalized regeneration of the tendon-bone interface. The gradient distribution of these scaffolds includes inorganic ion gradients and growth factor gradients. According to different gradients of the scaffold system, osteogenesis, chondrogenesis and tendon differentiation of cells at the tendon-bone interface are promoted, and the healing of the tendon-bone is synchronously completed to realize the repair and regeneration of the rotator cuff tendon-bone interface. Current studies indicated that gradient multiphase scaffolds had high academic research value and guided significance for future clinical applications in the reconstruction of the tendon-bone interface. In this paper, the factors affecting the development and regeneration of the tendon-bone interface are reviewed, and the effects of these factors on osteogenesis, chondrogenesis and tendon formation of various regions in promoting rotator cuff tendon-bone interface repair are summarized. The properties and effects of reported gradient multiphase scaffolds for rotator cuff injury are discussed, including gradient scaffolds containing inorganic ions and growth factors. Finally, the problems and future development opportunities of gradient multiphase support in rotator cuff repair are summarized.

13.
Chinese Journal of Medical Instrumentation ; (6): 598-601, 2023.
Artigo em Chinês | WPRIM | ID: wpr-1010246

RESUMO

The composite material PLGA compounded with β-tricalcium phosphate (β-TCP) was prepared by melt blending method, and the absorbable interface screw was prepared by injection molding process. Prepare PBS buffer that simulates human body, conduct in vitro degradation experiments on interface screws according to relevant national and industry standards, then test and characterize interface screws at different time points for degradation of intrinsic viscosity, average molecular weight distribution, mass loss, mechanical properties and thermal properties. According to the degradation performance-time curve, determine the time node at which the interface screw loses the mechanical properties. In this paper, the in vitro degradation behavior of interfacial screws prepared from PLGA and β-TCP composites was studied in detail, providing a reference and basis for the degradation behavior of absorbable products prepared from PLGA and β-TCP composites.


Assuntos
Humanos , Poliésteres , Teste de Materiais , Fosfatos de Cálcio , Implantes Absorvíveis
14.
Journal of Biomedical Engineering ; (6): 418-425, 2023.
Artigo em Chinês | WPRIM | ID: wpr-981558

RESUMO

The brain-computer interface (BCI) based on motor imagery electroencephalography (MI-EEG) enables direct information interaction between the human brain and external devices. In this paper, a multi-scale EEG feature extraction convolutional neural network model based on time series data enhancement is proposed for decoding MI-EEG signals. First, an EEG signals augmentation method was proposed that could increase the information content of training samples without changing the length of the time series, while retaining its original features completely. Then, multiple holistic and detailed features of the EEG data were adaptively extracted by multi-scale convolution module, and the features were fused and filtered by parallel residual module and channel attention. Finally, classification results were output by a fully connected network. The application experimental results on the BCI Competition IV 2a and 2b datasets showed that the proposed model achieved an average classification accuracy of 91.87% and 87.85% for the motor imagery task, respectively, which had high accuracy and strong robustness compared with existing baseline models. The proposed model does not require complex signals pre-processing operations and has the advantage of multi-scale feature extraction, which has high practical application value.


Assuntos
Humanos , Fatores de Tempo , Encéfalo , Eletroencefalografia , Imagens, Psicoterapia , Redes Neurais de Computação
15.
Journal of Biomedical Engineering ; (6): 409-417, 2023.
Artigo em Chinês | WPRIM | ID: wpr-981557

RESUMO

High-frequency steady-state asymmetric visual evoked potential (SSaVEP) provides a new paradigm for designing comfortable and practical brain-computer interface (BCI) systems. However, due to the weak amplitude and strong noise of high-frequency signals, it is of great significance to study how to enhance their signal features. In this study, a 30 Hz high-frequency visual stimulus was used, and the peripheral visual field was equally divided into eight annular sectors. Eight kinds of annular sector pairs were selected based on the mapping relationship of visual space onto the primary visual cortex (V1), and three phases (in-phase[0º, 0º], anti-phase [0º, 180º], and anti-phase [180º, 0º]) were designed for each annular sector pair to explore response intensity and signal-to-noise ratio under phase modulation. A total of 8 healthy subjects were recruited in the experiment. The results showed that three annular sector pairs exhibited significant differences in SSaVEP features under phase modulation at 30 Hz high-frequency stimulation. And the spatial feature analysis showed that the two types of features of the annular sector pair in the lower visual field were significantly higher than those in the upper visual field. This study further used the filter bank and ensemble task-related component analysis to calculate the classification accuracy of annular sector pairs under three-phase modulations, and the average accuracy was up to 91.5%, which proved that the phase-modulated SSaVEP features could be used to encode high- frequency SSaVEP. In summary, the results of this study provide new ideas for enhancing the features of high-frequency SSaVEP signals and expanding the instruction set of the traditional steady state visual evoked potential paradigm.


Assuntos
Humanos , Potenciais Evocados Visuais , Interfaces Cérebro-Computador , Voluntários Saudáveis , Razão Sinal-Ruído
16.
Journal of Biomedical Engineering ; (6): 358-364, 2023.
Artigo em Chinês | WPRIM | ID: wpr-981550

RESUMO

The development and potential application of brain-computer interface (BCI) technology is closely related to the human brain, so that the ethical regulation of BCI has become an important issue attracting the consideration of society. Existing literatures have discussed the ethical norms of BCI technology from the perspectives of non-BCI developers and scientific ethics, while few discussions have been launched from the perspective of BCI developers. Therefore, there is a great need to study and discuss the ethical norms of BCI technology from the perspective of BCI developers. In this paper, we present the user-centered and non-harmful BCI technology ethics, and then discuss and look forward on them. This paper argues that human beings can cope with the ethical issues arising from BCI technology, and as BCI technology develops, its ethical norms will be improved continuously. It is expected that this paper can provide thoughts and references for the formulation of ethical norms related to BCI technology.


Assuntos
Humanos , Interfaces Cérebro-Computador , Tecnologia , Encéfalo , Interface Usuário-Computador , Eletroencefalografia
17.
Chinese Journal of Ocular Fundus Diseases ; (6): 1-4, 2023.
Artigo em Chinês | WPRIM | ID: wpr-995586

RESUMO

Vitreoretinal interface is consisted of posterior vitreous cortex, retina internal limiting membrane, and extracellular matrix between them. Basement membrane-like complex is formed in the interface. The interface in children is of much difference with that in adult. The adhesion of it is much tight in children. The posterior edge of vitreous base is closed to ora serrata. The retina internal limiting membrane is thin. But with age, the posterior margin of vitreous base extends posteriorly, internal limiting membrane thickens and its elasticity decreases, the adhesion in vitreoretinal interface weakens, and posterior vitreous detachment develops. To recognize fully the interface in children is of much importance for understanding the pathophysiology and treatment strategy of pediatric vitreoretinal diseases.

18.
Chinese Journal of Rehabilitation Theory and Practice ; (12): 223-230, 2023.
Artigo em Chinês | WPRIM | ID: wpr-965035

RESUMO

ObjectiveTo conduct a visualized analysis of the research related to the use of brain-computer interface technology for stroke rehabilitation in the past ten years, and identify and predict the hot spots and hot trends in order to promote the further development of this field. MethodsThe Web of Science Core Collection database was searched for literature related to brain-computer interface technology for stroke rehabilitation from January, 2011 to October, 2022. CiteSpace 5.8.R3 was used to analyze the number of publications, countries, institutions, authors, keywords, co-citations, and grant support. Results and ConclusionA total of 592 papers were included, and the annual number of publications in this field of research showed a rapid growth trend, and the research enthusiasm continued to increase. The United States was in the leading position in this field, with the highest number of cooperative publications and the highest intermediary centrality; China had certain advantages in this field, but still needed to strengthen the exchange and cooperation with other countries/regions. Foreign institutions and authors had formed a network of close cooperative relationships, and formed a high-impact team represented by Niels Birbaumer, Cuntai Guan, Kai Keng Ang, etc.; there were poor cooperative relationships among domestic authors and institutions, and there were geographical restrictions and lack of high-impact academic groups. The keywords "motor imagery" and "recovery" formed ten major clusters and 15 prominent words with high variation rates, showing a trend of diversification in research directions. The study of the efficacy of upper limb motor rehabilitation and central mechanisms has been the hot topics in this field and will continue for some time in the future; the use of lower limb brain-computer interface systems for improving foot drop, gait and balance in stroke patients and the application of multimodal brain-computer interfaces will probably become a hot topic in the future. Finally, the use of brain-computer interface-guided neurofeedback training for cognitive and language rehabilitation in stroke also needs attention.

19.
International Eye Science ; (12): 1044-1048, 2023.
Artigo em Chinês | WPRIM | ID: wpr-973802

RESUMO

AIM: To compare the changes in corneal densitometry after small incision lenticule extraction(SMILE)and femtosecond laser in situ keratomileusis(FS-LASIK)and investigate the effect of corneal interface haze on vision after SMILE.METHODS: Prospective cohort study. A total of 93 patients(186 eyes)who were scheduled to undergo refractive surgery at the Ophthalmic Refractive Surgery Center of the Affiliated Hospital of Nantong University from May 2020 to October 2021 were included in the study, and there were 48 patients(96 eyes)in the SMILE group and 45 patients(90 eyes)in the FS-LASIK group. The changes in corneal densitometry, spherical equivalent(SE), and uncorrected visual acuity(UCVA)were observed and compared between the two groups before and at 1d, 1wk, 1, 3 and 6mo after surgery.RESULTS: The 93 patients all successfully completed the surgery, and there were no related complications during and after the surgery, and there were no lost cases. The UCVA of FS-LASIK group was 0.044±0.064 and -0.001±0.065 respectively at 1d and 1wk after surgery, which was better than that of SMILE group(0.102±0.077 and 0.023±0.064; all P&#x003C;0.05). There was no statistical difference in the SE between the two groups at the postoperative follow-ups(P&#x003E;0.05). The corneal densitometry values at 0-2 and 2-6 mm from corneal vertex and total corneal densitometry at 1d postoperatively in the FS-LASIK group were 18.0(17.5, 18.6), 16.2(15.6, 16.7)and 16.7(16.1, 17.3), which were lower than those of SMILE group [18.6(18.1, 19.3), 16.8(16.4, 17.4), 17.2(16.6, 17.8)](all P&#x003C;0.05); The corneal densitometry values at 0-2 and 2-6 mm from corneal vertex and total corneal densitometry at 1wk postoperatively in the FS-LASIK group were 17.2(16.7, 17.6), 15.5(15.0, 15.9)and 15.9(15.3, 16.7), which were lower than those of SMILE group [17.6(17.1, 18.3), 16.0(15.6, 16.5), 16.6(15.9, 17.1)](all P&#x003C;0.05).CONCLUSIONS: The transient interface haze after SMILE is responsible for the early higher corneal densitometry than FS-LASIK. The presence of interface haze is probably a factor for the quality of vision.

20.
Journal of Environmental and Occupational Medicine ; (12): 515-519, 2023.
Artigo em Chinês | WPRIM | ID: wpr-973640

RESUMO

Diesel exhaust (DE) is an important pollution source widely existing in the living and production environment, which is closely related to the health of the public and occupational groups. The International Agency for Research on Cancer has classified DE as a Group 1 carcinogen. Considering the negative health impacts on the respiratory system due to DE exposure in vitro, it is crucial to apply reliable test systems allowing accurate assessment of the biological effects of DE. The exposure technology of respiratory system in vitro is considered as one of the feasible measures to implement the 3R (reduce, refine, and replace) principle in animal experiments. Compared with the traditional submerged culture in vitro models, the air-liquid interface (ALI) exposure technology has the advantages including fewer influencing factors, easier exposure condition control, and shorter exposure cycle. ALI has become an important tool to study molecular events associated with physiology and pathology of respiratory system, and action modes and interactions of different cell types. Also, ALI has been increasingly widely used because it can simulate the actual processes of human respiratory system cells and/or tissues to DE exposure. This review was intended to introduce the development and advantages of ALI exposure technology, and further summarized the application progress of ALI exposure technology in studying the respiratory toxicity induced by DE exposure in vitro, so as to provide new ideas and pathways for the use of ALI exposure technology in the study of biomarkers and mechanisms of respiratory toxicity associated with DE exposure, and provide basic data to screen and promote biomarkers for exposed populations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA