Complexos polieletrólitos de quitosana e xantana carregados com ativos naturais e sintéticos: estudo físico/químico e microbiológico para aplicação de drug delivery / Polyelectrolyte complexes of chitosan and xanthan loaded with natural and synthetic actives: physicochemical and microbiological study for drug delivery application

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)

Ideas and methods of in vitro model establishment for cell microenvironment in COPD / 中国药理学通报

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.

Effect of brain-computer interface based on visual, auditory and motor feedback combined with transcranial direct current stimulation on upper limb function in stroke patients / 中国康复理论与实践

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.

Methods for Improving Brain-Computer Interface: Using A Brain-Directed Adjuvant and A Second-Generation Artificial Intelligence System to Enhance Information Streaming and Effectiveness of Stimuli

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.

Evaluation of hydrophilic surface osseointegration in low-density bone: Preclinical study in rabbits

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.

Interface entre trabalho e família no período da pandemia da COVID-19: percepção de teletrabalhadores e gestores de Recursos Humanos / The interface between work and family in the period of the COVID-19 pandemic: perception of teleworkers and Human Resources managers / Interfaz entre trabajo y familia en el período de la pandemia de COVID-19: percepción de teletrabajadores y gestores de Recursos Humanos

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.

Protein interactions with osseointegrable titanium implants

This review aims to present the mechanisms of protein interactions with titanium dental implant surfaces. Methods: the analyses were based on searches of scientific articles available in English and Portuguese in PubMed (MEDLINE), Bireme (LILACS), Scielo, Web of Science and Google Scholar. Results: titanium dental implant treatments success rates (95-98%) are mainly due to the biocompatibility of titanium oxide on the implant surface, surgical techniques adopted, good implants manufacturing processes and biomechanical knowledge of the systems. Studies in past decades has empirically developed implant surfaces with significant changes in morphologies, roughness, wettability, surface energy, chemical composition, and chemical groups density or deposited molecules. These changes promoted better protein adsorption, osteoblast adhesion, and changes in the mechanisms involved in osseointegration. Thus, the time to put the implant in function has been reduced and the success rates have increased. In the osseointegration process, at the nanoscale, there is no contact between the bone and the implant surface, but there is the formation of a protein anchorage between the periosteum and the implant with an interface formed by proteins. In all the reactions between the body and the implant surface, the activities of fibronectin and integrin are essential, since they are responsible for transmitting information to the cell for its differentiation, adhesion and mobility. Conclusion: thus, the analyses of protein-implant interactions are indispensable for a better understanding of the performance of osseointegrated dental implants

Web version of the protocol of the orofacial myofunctional evaluation with scores: usability and learning / Versão para Web do protocolo de avaliação miofuncional com escores: usabilidade e aprendizado

ABSTRACT Purpose The Orofacial Myofunctional Evaluation with Scores (OMES) protocol has been validated and used in clinical practice and research. The goals of this study were to develop, analyze and improve a version of OMES for the Web and to investigate the relationship between the usability judgments and the prior experience of the evaluators and whether using the interface promotes learning, as shown by the task completion time (TCT). Methods Study steps: 1) inspection of the prototype by the team; 2) evaluation of usability by three experienced speech-language pathologists (SLPs); and 3) evaluation of its usability by 12 SLPs with varying levels of experience in the use of OMES. Participants answered the Heuristic evaluation (HE), the Computer System Usability Questionnaire (CSUQ), and expressed free comments. The TCT was recorded. Results The OMES-Web reached excellent usability levels, and the participants were highly satisfied. The correlations between the participants' experience and the HE and CSUQ scores were not significant. The TCT decreased significantly throughout the tasks. Conclusion OMES-Web meets the usability criteria, and participants feel satisfied with the system regardless of their level of experience. The fact that it is easy to learn favors its adoption by professionals.

RESUMO Objetivo O Protocolo de Avaliação Miofuncional Orofacial com Escores (AMIOFE) é validado e usado na prática clínica e pesquisas. Os objetivos deste estudo foram desenvolver, analisar e aprimorar a versão do AMIOFE para a Web e investigar a relação entre os julgamentos de usabilidade e a prévia experiência dos avaliadores, e se o manuseio da interface promove o aprendizado, baseado no tempo para completar a tarefa (TCT). Método Passos do estudo: 1) inspeção do protótipo pela equipe; 2) avaliação de usabilidade por três fonoaudiólogos experientes; e 3) avaliação de usabilidade por 12 fonoaudiólogos com variados níveis de experiência no uso do AMIOFE. Avaliação heurística (HE), Computer System Usability Questionnaire (CSUQ) e livre expressão dos participantes foram realizadas. O TCT foi registrado. Resultados O AMIOFE-Web atingiu ótimos níveis de usabilidade e os participantes mostram-se altamente satisfeitos (Escala geral do CSUQ; Média= 1,31, DP= 0,31). A relação da experiência dos participantes e a HE e o CSUQ não foi significativa. O TCT decresceu significantemente ao longo das tarefas, mostrando que o sistema é fácil de aprender e usar. Conclusão O AMIOFE-Web atende os critérios de usabilidade e os participantes sentiram-se satisfeitos com o sistema, independentemente de seus níveis de experiência. O fato de ser de fácil aprendizado é um fator favorável para a sua adoção por profissionais.

Effects of motorcycle exhaust on oxidative stress levels in cells of human respiratory tract / 中国职业医学

{L-End}Objective To investigate the effect of motorcycle exhaust (ME) on the level of oxidative stress in different parts of respiratory tract epithelial cells. {L-End}Methods BEAS-2B and A549 cells in logarithmic growth phase were randomly divided into control group, low- and high-dose groups. The two kinds of cells growing on the membrane of Transwell inserts were treated with air-liquid interface (ALI) exposure technique for 60 minutes. The cells in the low- and high- dose groups were treated with diluted gas with the volume ratio of ME to clean air of 1∶20 and 1∶10, respectively, while the cells in the control group were treated with clean air. Cells were collected to detect their relative survival rate using CCK-8 method after exposure. And the levels of malondialdehyde, glutathione and the activity of superoxide dismutase (SOD) of the cells were detected using colorimetry. {L-End}Results The ME exposure dose affected the relative survival rate of cells (P<0.01), which showed a downward trend with the increasing ME exposure doses (all P<0.05). However, there was no significant difference in the main effect of cell types and the interaction effect of ME exposure dose and cell type (all P>0.05). There was a significant interaction between ME exposure dose and cell type in the level of glutathione and the activity of SOD (all P<0.01), and the level of malondialdehyde was a significant main effect of cell type (P<0.01). There was no significant difference in the glutathione level and SOD activity between the low-dose group and the control group (all P>0.05), while the glutathione level and SOD activity in high-dose group were higher than those in the control group and low-dose group in BEAS-2B cells (all P<0.05). The glutathione level decreased with increasing ME exposure dose in A549 cells (all P<0.05). Compared with the control group, the low-dose group had a significantly higher activity of SOD (P<0.05) in A549 cells. The SOD activity of A549 cells in high-dose group was lower than those in control group and low-dose group (all P<0.05). The level of malondialdehyde in A549 cells was higher than those in BEAS-2B cells(P<0.05). {L-End}Conclusion ME exposure can lead to changes in the production of oxidative stress biomarkers in respiratory tract epithelial cells. The oxidative stress response induced by ME exposure varies among respiratory tract epithelial cells from different regions.

Modified application of interface screw in femoral side during anterior cruciate ligament reconstruction / 中国骨伤

OBJECTIVE@#To compare clinical effects of the improved interface screw fixation of femoral end of anterior cruciate ligament with classic femoral lateral loop plate fixation.@*METHODS@#A retrospective analysis of 65 patients who underwent arthroscopic anterior cruciate ligament reconstruction from January 2019 to September 2021 were performed. According to the different fixation methods of the femoral side, 35 patients were divided into loop plate fixation(loop plate group), including 27 males and 8 females, aged from 18 to 50 years old with an average of (35.00±7.60) years old;30 patients in interface screw fixation(interface screw group), including 20 males and 10 females, aged from 18 to 50 years old with an average of (32.00±8.50) years old. Hospital stay, hospital expenses, operation time, complications, C-reactive protein at 1, 3, 6 days after operation, and postoperative Lysholm score and International Knee Documentation Committee(IKDC) score at 18 months were compared between two groups.@*RESULTS@#All patients were successfully operated, and obtained follow-up from 18 to 36 months with an average of (25.16±4.50) months. Anterior drawer test and Lachman test of all patients turned to negative. There were no statistical differences in hospital stay, hospital expenses and complications between two groups(P>0.05);operation time in loop plate group was (74.00±6.84) min, and (91.67±6.34) min in interface screw group, and had difference between two groups(P<0.05). C-reactive protein on the 1st and 3rd day after operation was (40.00±10.10), (20.00±8.23) mg·L-1 in loop plate group, and (60.00±8.93), (30.00±8.66) mg·L-1 in interface nail group, had statistical difference between two groups (P<0.05);while there was no difference in C-reactive protein on the 6th day after operation(P>0.05). At 18 months after operation, Lysholm and IKDC scores showed no significant difference between two groups (P>0.05). In loop plate group, medullary enlargement on coronal and sagittal views were (2.75±0.19) mm, (1.55±0.25) mm, and (2.81±0.22) mm, (1.61±0.20) mm in interface screw group, and had statistical difference between two groups(P<0.05).@*CONCLUSION@#In the reconstruction of anterior cruciate ligament, the common interface screw on the femoral side is changed to the sheath interface screw, and intramedullary screw is changed to the compression and fixation of tendon from outside to inside of joint. Although the operation procedure is relatively complicated and operation time is slightly longer, it has advantages of no residual metal foreign body after operation, and clinical effect is no different from classical loop plate suspension fixation, which is still a good choice.

Targeted muscle reinnervation: a surgical technique of human-machine interface for intelligent prosthesis / 中国修复重建外科杂志

OBJECTIVE@#To review targeted muscle reinnervation (TMR) surgery for the construction of intelligent prosthetic human-machine interface, thus providing a new clinical intervention paradigm for the functional reconstruction of residual limbs in amputees.@*METHODS@#Extensively consulted relevant literature domestically and abroad and systematically expounded the surgical requirements of intelligent prosthetics, TMR operation plan, target population, prognosis, as well as the development and future of TMR.@*RESULTS@#TMR facilitates intuitive control of intelligent prostheses in amputees by reconstructing the "brain-spinal cord-peripheral nerve-skeletal muscle" neurotransmission pathway and increasing the surface electromyographic signals required for pattern recognition. TMR surgery for different purposes is suitable for different target populations.@*CONCLUSION@#TMR surgery has been certified abroad as a transformative technology for improving prosthetic manipulation, and is expected to become a new clinical paradigm for 2 million amputees in China.

Research progress of brain-computer interface application paradigms based on rapid serial visual presentation / 生物医学工程学杂志

Rapid serial visual presentation (RSVP) is a type of psychological visual stimulation experimental paradigm that requires participants to identify target stimuli presented continuously in a stream of stimuli composed of numbers, letters, words, images, and so on at the same spatial location, allowing them to discern a large amount of information in a short period of time. The RSVP-based brain-computer interface (BCI) can not only be widely used in scenarios such as assistive interaction and information reading, but also has the advantages of stability and high efficiency, which has become one of the common techniques for human-machine intelligence fusion. In recent years, brain-controlled spellers, image recognition and mind games are the most popular fields of RSVP-BCI research. Therefore, aiming to provide reference and new ideas for RSVP-BCI related research, this paper reviewed the paradigm design and system performance optimization of RSVP-BCI in these three fields. It also looks ahead to its potential applications in cutting-edge fields such as entertainment, clinical medicine, and special military operations.

Recognition of motor imagery electroencephalogram based on flicker noise spectroscopy and weighted filter bank common spatial pattern / 生物医学工程学杂志

Due to the high complexity and subject variability of motor imagery electroencephalogram, its decoding is limited by the inadequate accuracy of traditional recognition models. To resolve this problem, a recognition model for motor imagery electroencephalogram based on flicker noise spectrum (FNS) and weighted filter bank common spatial pattern ( wFBCSP) was proposed. First, the FNS method was used to analyze the motor imagery electroencephalogram. Using the second derivative moment as structure function, the ensued precursor time series were generated by using a sliding window strategy, so that hidden dynamic information of transition phase could be captured. Then, based on the characteristic of signal frequency band, the feature of the transition phase precursor time series and reaction phase series were extracted by wFBCSP, generating features representing relevant transition and reaction phase. To make the selected features adapt to subject variability and realize better generalization, algorithm of minimum redundancy maximum relevance was further used to select features. Finally, support vector machine as the classifier was used for the classification. In the motor imagery electroencephalogram recognition, the method proposed in this study yielded an average accuracy of 86.34%, which is higher than the comparison methods. Thus, our proposed method provides a new idea for decoding motor imagery electroencephalogram.

Applications and challenges of wearable electroencephalogram signals in depression recognition and personalized music intervention / 生物医学工程学杂志

Rapid and accurate identification and effective non-drug intervention are the worldwide challenges in the field of depression. Electroencephalogram (EEG) signals contain rich quantitative markers of depression, but whole-brain EEG signals acquisition process is too complicated to be applied on a large-scale population. Based on the wearable frontal lobe EEG monitoring device developed by the authors' laboratory, this study discussed the application of wearable EEG signal in depression recognition and intervention. The technical principle of wearable EEG signals monitoring device and the commonly used wearable EEG devices were introduced. Key technologies for wearable EEG signals-based depression recognition and the existing technical limitations were reviewed and discussed. Finally, a closed-loop brain-computer music interface system for personalized depression intervention was proposed, and the technical challenges were further discussed. This review paper may contribute to the transformation of relevant theories and technologies from basic research to application, and further advance the process of depression screening and personalized intervention.

A design and evaluation of wearable p300 brain-computer interface system based on Hololens2 / 生物医学工程学杂志

Patients with amyotrophic lateral sclerosis ( ALS ) often have difficulty in expressing their intentions through language and behavior, which prevents them from communicating properly with the outside world and seriously affects their quality of life. The brain-computer interface (BCI) has received much attention as an aid for ALS patients to communicate with the outside world, but the heavy device causes inconvenience to patients in the application process. To improve the portability of the BCI system, this paper proposed a wearable P300-speller brain-computer interface system based on the augmented reality (MR-BCI). This system used Hololens2 augmented reality device to present the paradigm, an OpenBCI device to capture EEG signals, and Jetson Nano embedded computer to process the data. Meanwhile, to optimize the system's performance for character recognition, this paper proposed a convolutional neural network classification method with low computational complexity applied to the embedded system for real-time classification. The results showed that compared with the P300-speller brain-computer interface system based on the computer screen (CS-BCI), MR-BCI induced an increase in the amplitude of the P300 component, an increase in accuracy of 1.7% and 1.4% in offline and online experiments, respectively, and an increase in the information transfer rate of 0.7 bit/min. The MR-BCI proposed in this paper achieves a wearable BCI system based on guaranteed system performance. It has a positive effect on the realization of the clinical application of BCI.

Recognition of high-frequency steady-state visual evoked potential for brain-computer interface / 生物医学工程学杂志

Coding with high-frequency stimuli could alleviate the visual fatigue of users generated by the brain-computer interface (BCI) based on steady-state visual evoked potential (SSVEP). It would improve the comfort and safety of the system and has promising applications. However, most of the current advanced SSVEP decoding algorithms were compared and verified on low-frequency SSVEP datasets, and their recognition performance on high-frequency SSVEPs was still unknown. To address the aforementioned issue, electroencephalogram (EEG) data from 20 subjects were collected utilizing a high-frequency SSVEP paradigm. Then, the state-of-the-art SSVEP algorithms were compared, including 2 canonical correlation analysis algorithms, 3 task-related component analysis algorithms, and 1 task discriminant component analysis algorithm. The results indicated that they all could effectively decode high-frequency SSVEPs. Besides, there were differences in the classification performance and algorithms' speed under different conditions. This paper provides a basis for the selection of algorithms for high-frequency SSVEP-BCI, demonstrating its potential utility in developing user-friendly BCI.

In Vitro Degradation Behavior of Absorbable Interface Screws / 中国医疗器械杂志

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.

Roadmap of Medical Device for Implanted Brain-computer Interface / 中国医疗器械杂志

Implanted brain-computer interface (iBCI) is a system that establishes a direct communication channel between human brain and computer or an external devices by implanted neural electrode. Because of the good functional extensibility, iBCI devices as a platform technology have the potential to bring benefit to people with nervous system disease and progress rapidly from fundamental neuroscience discoveries to translational applications and market access. In this report, the industrialization process of implanted neural regulation medical devices is reviewed, and the translational pathway of iBCI in clinical application is proposed. However, the Food and Drug Administration (FDA) regulations and guidances for iBCI were expounded as a breakthrough medical device. Furthermore, several iBCI products in the process of applying for medical device registration certificate were briefly introduced and compared recently. Due to the complexity of iBCI in clinical application, the translational applications and industrialization of iBCI as a medical device need the closely cooperation between regulatory departments, companies, universities, institutes and hospitals in the future.

Effect of brain-computer interface training based on motor imagery on hand function for subacute stroke patients / 中国康复理论与实践

ObjectiveTo observe the effect of brain-computer interface (BCI) training based on motor imagery on hand function in hemiplegic patients with subacute stroke. MethodsFrom June, 2020 to December, 2021, 40 patients with hemiplegia in subacute stroke from Department of Rehabilitation Medicine, Fifth Affiliated Hospital of Zhengzhou University were divided into control group (n = 20) and experimental group (n = 20) using random number table. Both groups accepted medication and routine comprehensive rehabilitation, while the control group accepted hand rehabilitation robot training, and the experimental group accepted the robot training using motor imagery-based BCI, for four weeks. They were assessed with Fugl-Meyer Assessment-Upper Extremities (FMA-UE), modified Barthel Index, modified Ashworth scale, and measured integrated electromyogram of the superficial finger flexors, finger extensors and short thumb extensors of the affected forearm during maximum isometric voluntary contraction with surface electromyography. ResultsTwo patients in the control group and one in the experimental group dropped off. All the indexes improved in both groups after treatment (t > 2.322, Z > 2.631, P < 0.05), and they were better in the experimental group than in the control group (t > 2.227, Z > 2.078, P < 0.05), except the FMA-UE score of wrist. ConclusionMotor imagery-based BCI training is more effective on hand function and activities of daily living in hemiplegic patients with subacute stroke.

Advances in brain-computer interface based on high-frequency steady-state visual evoked potential / 生物医学工程学杂志

Steady-state visual evoked potential (SSVEP) has been widely used in the research of brain-computer interface (BCI) system in recent years. The advantages of SSVEP-BCI system include high classification accuracy, fast information transform rate and strong anti-interference ability. Most of the traditional researches induce SSVEP responses in low and middle frequency bands as control signals. However, SSVEP in this frequency band may cause visual fatigue and even induce epilepsy in subjects. In contrast, high-frequency SSVEP-BCI provides a more comfortable and natural interaction despite its lower amplitude and weaker response. Therefore, it has been widely concerned by researchers in recent years. This paper summarized and analyzed the related research of high-frequency SSVEP-BCI in the past ten years from the aspects of paradigm and algorithm. Finally, the application prospect and development direction of high-frequency SSVEP were discussed and prospected.