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1.
Artigo em Inglês | MEDLINE | ID: mdl-33800119

RESUMO

Quantitative assessment is crucial for the evaluation of human postural balance. The force plate system is the key quantitative balance assessment method. The purpose of this study is to review the important concepts in balance assessment and analyze the experimental conditions, parameter variables, and application scope based on force plate technology. As there is a wide range of balance assessment tests and a variety of commercial force plate systems to choose from, there is room for further improvement of the test details and evaluation variables of the balance assessment. The recommendations presented in this article are the foundation and key part of the postural balance assessment; these recommendations focus on the type of force plate, the subject's foot posture, and the choice of assessment variables, which further enriches the content of posturography. In order to promote a more reasonable balance assessment method based on force plates, further methodological research and a stronger consensus are still needed.


Assuntos
Equilíbrio Postural , Postura , , Humanos , Posição Ortostática
2.
Rev Sci Instrum ; 91(8): 085106, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32872932

RESUMO

A combined measurement method on the basis of liquid compressibility and the characteristics of deep sea pressure compensators and pistons is proposed to solve the difficulty in measuring the large pressure of several kilometers of water depth and the small fluctuation pressure of several centimeters of water depth in ocean pressure detection. First, the working principle of the proposed method is introduced. Second, the force of piston is evaluated under static and dynamic pressure measurement conditions, and the corresponding mathematical models are established. Third, the measurement accuracy of static and dynamic pressures is analyzed. Finally, a test platform is built. The results show that the maximum dynamic pressure of 0.025 bar is realized at a pressure changing speed of 0.2 bar/s, and the small fluctuation pressure of 2.8 × 10-3 bars is realized at a pressure of 20 bars. The measurement system can track the changing ambient pressure in real time, and the measurement accuracy of the small fluctuation pressure is only related to the characteristics of the measurement system itself but not to the external large pressure. The accuracy and feasibility of the proposed method are verified. This study provides a new approach for measuring deep sea large pressure and its small fluctuation pressure.

3.
Curr Alzheimer Res ; 16(12): 1132-1142, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31670622

RESUMO

BACKGROUND: Alzheimer's Disease (AD) is the most common neurodegenerative disorder, and it is still incurable. Early diagnosis and intervention are crucial for delaying the onset and progression of the disease. Mounting evidence indicates that the neurotoxic effects might be attributed to Soluble ß-Amyloid Oligomers (SAßO). The SAßO are believed to be neurotoxic peptides more predominant than Aß plaques in the early stage, and their key role in AD is self-evident. Unfortunately, identification of SAßO proves to be difficult due to their heterogeneous and transient nature. In spite of many obstacles, multiple techniques have recently been developed to target SAßO effectively. This review focuses on the recent progress in the approaches towards SAßO detection in order to shed some light on the future development of SAßO assays. METHODS: Literatures were obtained from the following libraries: Web of Science, PubMed, EPO, SIPO, USPTO. Articles were critically reviewed based on their titles, abstracts, and contents. RESULTS: A total of 85 papers are referenced in the review. Results are divided into three categories based on the types of detection methods: small molecule fluorescence probes, oligomer-specific antibodies and electrochemical biosensors. Finally, the improvements and challenges of these approaches applied in the early diagnosis of AD were discussed. CONCLUSION: This review article covers three kinds of strategies that could be translated into clinic practice and lead to earlier diagnosis and therapeutic interventions of AD.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Corantes Fluorescentes/metabolismo , Sistemas de Liberação de Medicamentos/tendências , Diagnóstico Precoce , Humanos , Placa Amiloide/diagnóstico por imagem , Placa Amiloide/metabolismo
4.
Sensors (Basel) ; 18(9)2018 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-30223599

RESUMO

A novel elastic body design idea of six-axis wrist force sensor with a floating beam was raised based on the analysis of the robot six-axis wrist force sensor with a floating beam. The design ideas improve the sensor's dynamic performance significantly, while not reducing its sensitivity. First, the design ideas were described in detail, which were analyzed by mechanical modeling and were verified by finite element analysis. Second, the static simulation analysis of the novel elastomer of sensor was carried out. According to the strain distribution performance, the position of the strain gauges pasted and the connection mode of the full-bridge circuits were decided, which can achieve theoretical decoupling. Finally, the comparison between the static and dynamic performance of the novel sensor and the original sensor with floating beams was done. The results show that the static and dynamic performance of the novel six-axis wrist sensor are all better than the original sensor.

5.
IEEE Trans Neural Syst Rehabil Eng ; 26(7): 1424-1434, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29985152

RESUMO

To facilitate stretch reflex onset (SRO) detection and improve accuracy and reliability of spasticity assessment in clinical settings, a new method to measure dynamic stretch reflex threshold (DSRT) based on Hilbert-Huang transform marginal spectrum entropy (HMSEN) of surface electromyography (sEMG) signals and a portable system to quantify modified Ashworth scale (MAS) for spasticity assessment were developed. The sEMG signals were divided into frames using a fixed-length sliding window, and the HMSEN of each frame was calculated. An adaptive threshold was set to measure the DSRT. The HMSEN based method can quantify muscle activity through time-frequency and nonlinear dynamics analysis, therefore providing deeper insight about the spastic muscle mechanisms during stretching and a reliable SRO detection method. Experimental results revealed that the HMSEN based method could reliably detect the SRO and measure the DSRT (recognition rate: 95.45%), and could achieve improved performance over the time-domain based method. There was a strong correlation ( to -0.900) between the MAS scores and the DSRT index, and the test-retest reliability was high. Additionally, limitations of the MAS were analyzed. This paper indicates that the presented framework can provide a promising tool to measure DSRT and a clinical quantitative approach for spasticity assessment.


Assuntos
Eletromiografia/métodos , Entropia , Espasticidade Muscular/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Braço/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Espasticidade Muscular/fisiopatologia , Dinâmica não Linear , Reflexo de Estiramento , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/fisiopatologia , Adulto Jovem
6.
Bioorg Med Chem ; 26(5): 1050-1061, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29426629

RESUMO

A novel series of non-peptide proteasome inhibitors (PIs) that act on chymotrypsin-like (ChT-L) of the proteasome were developed. These PIs bearing 4-aromatic sulfonyl naphthalene-based scaffold and Leu-boronic moiety as covalent bonding group displayed far better activity than PI-8182 for inhibiting ChT-L in preliminary biological activity test. The results showed that 2a (IC50 = 6.942 µM, MCF-7) and 2c (IC50 = 6.905 µM, MCF-7) displayed higher anti-proliferative activities than Bortezomib (IC50 = 18.37 µM, MCF-7) under our experimental conditions. Furthermore, in the microsomal stability assay, 2a demonstrated excellent metabolic stability profiles with 56% remaining after 40 min, as compared to Bortezomib of which approximately 30% was remaining. The compounds 2a, 2c emerged as promising lead compounds for the development of novel non-peptide boronate PIs.


Assuntos
Ácidos Borônicos/química , Naftalenos/química , Complexo de Endopeptidases do Proteassoma/química , Inibidores de Proteassoma/química , Sítios de Ligação , Ácidos Borônicos/síntese química , Ácidos Borônicos/farmacologia , Bortezomib/farmacologia , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Humanos , Células MCF-7 , Microssomos/metabolismo , Simulação de Acoplamento Molecular , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/síntese química , Inibidores de Proteassoma/farmacologia , Relação Estrutura-Atividade
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