Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros

Base de dados
Tipo de documento
Assunto da revista
País de afiliação
Intervalo de ano de publicação
1.
Sensors (Basel) ; 24(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38339535

RESUMO

In the realm of sensorless control for a permanent magnet synchronous motor (PMSM), the flux observer algorithm is widely recognized. However, the estimation accuracy of rotor position is adversely impacted by the interference from DC bias and high-order harmonics. To address these issues, an advanced flux observation method, second-order generalized integrator flux observer extend (SOGIFO-X), is introduced in this paper. The study begins with a theoretical analysis to establish the relationship between flux observation error and rotor position error. The SOGIFO-X method, developed in this study, is compared with traditional methods such as the Low Pass Filter (LPF) and second-order generalized integrator flux observer (SOGIFO), employing mathematical rigor and Bode plot analysis. The emphasis is on the methodology and the general performance improvements SOGIFO-X offers over conventional methods. Simulations and experiments were conducted to assess the impact of SOGIFO-X on the steady-state and dynamic performances of sensorless control. Findings indicate that SOGIFO-X demonstrates significant enhancements in terms of reducing the reduced flux observation error, contributing to the advancement of position estimation accuracy and sensorless motor control technology.

2.
Sensors (Basel) ; 24(6)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38544247

RESUMO

Assessing bladder function is pivotal in urological health, with bladder volume a critical indicator. Traditional devices, hindered by high costs and cumbersome sizes, are being increasingly supplemented by portable alternatives; however, these alternatives often fall short in measurement accuracy. Addressing this gap, this study introduces a novel A-mode ultrasound-based bladder volume estimation algorithm optimized for portable devices, combining efficient, precise volume estimation with enhanced usability. Through the innovative application of a wavelet energy ratio adaptive denoising method, the algorithm significantly improves the signal-to-noise ratio, preserving critical signal details amidst device and environmental noise. Ultrasonic echoes were employed to acquire positional information on the anterior and posterior walls of the bladder at several points, with an ellipsoid fitted to these points using the least squares method for bladder volume estimation. Ultimately, a simulation experiment was conducted on an underwater porcine bladder. The experimental results indicate that the bladder volume estimation error of the algorithm is approximately 8.3%. This study offers a viable solution to enhance the accuracy and usability of portable devices for urological health monitoring, demonstrating significant potential for clinical application.


Assuntos
Algoritmos , Bexiga Urinária , Animais , Suínos , Bexiga Urinária/diagnóstico por imagem , Ultrassonografia , Simulação por Computador , Imagens de Fantasmas , Razão Sinal-Ruído , Análise de Ondaletas
3.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 51(5): 563-572, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36581582

RESUMO

OBJECTIVE: To investigate the effect and mechanism of Pinus massoniana needle extracts (PNE) on oxidative stress injury in cerebral ischemia reperfusion rats. METHODS: The SD male rats were randomly divided into sham group, model control group, Edaravone (3 mg/kg) group, PNE low-dose (200 mg/kg), medium-dose (400 mg/kg) and high-dose (800 mg/kg) groups. PNE was administered by gavage for 7 d before modeling and 6 h after modeling in PNE treatment groups; Edaravone was given by intraperitoneal injection 7 d before modeling and 6 h after reperfusion. The rat model of cerebral ischemia reperfusion injury was established by middle cerebral artery occlusion method. After 24 h of reperfusion, the neurological deficit score, brain water content and cerebral infarction volume of rats were measured. The pathological changes of cerebral cortex and hippocampus were observed by HE staining, and the number of normal nerve cells was counted. The apoptosis rate of neurons in cerebral cortex was detected by TUNEL method. The content of nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD) activity in ischemic brain tissue were detected. The protein expression of c-Jun N-terminal kinase (JNK) 3, phosphorylated JNK3 (p-JNK3), B-cell lymphoma protein(Bcl) -2, Bcl-2 associated X (Bax), cytochrome C and caspase-3 in cerebral cortex were detected by Western blotting method. RESULTS: Compared with the model control group, the behavioral score, brain water content and cerebral infarction volume in PNE groups were significantly reduced (all P<0.05), the pathological damage of cerebral cortex and hippocampal CA1 area was significantly alleviated, and the number of normal nerve cells in ischemic cortex and hippocampal CA1 area was increased (all P<0.05). The medium-dose PNE group had the best effect. Compared with the model control group, the apoptosis rate of cortical neurons, the content of NO and MDA in cerebral cortex, the ratio of p-JNK3/JNK3, the expression level of cytochrome C and caspase-3 protein in PNE medium-dose group were significantly reduced , and the activity of SOD, the Bcl-2/Bax ratio were significantly improved (all P<0.05). CONCLUSION: PNE ameliorates brain injury after cerebral ischemia reperfusion in rats, which may be related to scavenging NO and MDA, inhibiting oxidative stress-mediated JNK3/caspase-3 signsal transduction to inhibit neuronal apoptosis.


Assuntos
Isquemia Encefálica , Estresse Oxidativo , Extratos Vegetais , Traumatismo por Reperfusão , Animais , Masculino , Ratos , Apoptose , Proteína X Associada a bcl-2/metabolismo , Proteína X Associada a bcl-2/farmacologia , Proteína X Associada a bcl-2/uso terapêutico , Isquemia Encefálica/tratamento farmacológico , Caspase 3/metabolismo , Caspase 3/farmacologia , Citocromos c/metabolismo , Citocromos c/farmacologia , Citocromos c/uso terapêutico , Edaravone/farmacologia , Edaravone/uso terapêutico , Infarto da Artéria Cerebral Média , Ratos Sprague-Dawley , Reperfusão , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais , Superóxido Dismutase , Extratos Vegetais/farmacologia , Pinus/química
4.
Neurochem Res ; 46(7): 1869-1880, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34031841

RESUMO

Piceatannol is a natural plant-derived compound with protective effects against cardiovascular diseases. However, its effect on cerebral ischaemia-reperfusion injury (CIRI) induced by oxidative stress remains unclear. This study aimed to investigate piceatannol's antioxidation in CIRI. An in vitro oxygen-glucose deprivation followed by reoxygenation model was used and cell viability was measured. A middle cerebral artery occlusion followed by reperfusion model was used in vivo. Neurological function, encephalisation quotient, oedema, and volume of the cerebral infarction were then evaluated. The effects of piceatannol on histopathological findings, as well as the ultrastructure of the cortex, were analysed. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and lactate dehydrogenase (LDH) and the malondialdehyde (MDA) content was measured both in vitro and in vivo. Finally, the expression of nuclear factor erythroid-2-related factor 2 (Nrf2), hemeoxygenase-1 (HO-1), and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 (NQO1) in cerebral tissue was detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. Our results demonstrated that cell viability in the piceatannol groups was increased. The SOD, GSH-Px activities were increased as LDH activity and MDA content decreased in the piceatannol groups both in vitro and in vivo, reflecting a decrease in oxidative stress. The neurological severity score and infarction volume in the piceatannol groups at doses of 10 and 20 mg/kg were lower than those of the model group. Furthermore, the damage seen on histopathological examination was partially attenuated by piceatannol. RT-qPCR and western blot analysis indicated that the expression of Nrf2, HO-1, and NQO1 were significantly increased by piceatannol. The results of the study demonstrate that piceatannol exerts a protective effect against CIRI.


Assuntos
Infarto da Artéria Cerebral Média/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Estilbenos/uso terapêutico , Animais , Encéfalo/patologia , Hipóxia Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Glucose/deficiência , Heme Oxigenase-1/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos ICR , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia
5.
Environ Int ; 191: 108969, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39180774

RESUMO

Emerging mycotoxins enniatins (ENNs) and beauvericin (BEA) pose potential health risks to humans through dietary exposure. However, research into their mechanisms of toxicity is limited, with a lack of comprehensive toxicological data. This study investigates from a hepatic lipid metabolism perspective, establishing a more precise and reliable 3D HepaRG hepatocyte spheroid model as an alternative for toxicity assessment. Utilizing physiological indices, histopathological analyses, lipidomics, and molecular docking techniques, it comprehensively elucidates the effects of ENNs and BEA on hepatic lipid homeostasis and their molecular toxicological mechanisms. Our findings indicate that ENNs and BEA impact cellular viability and biochemical functions, significantly altering lipid metabolism pathways, particularly those involving glycerophospholipids and sphingolipids. Molecular docking has demonstrated strong binding affinity of ENNs and BEA with key enzymes in lipid metabolism such as Peroxisome Proliferator-Activated Receptor α (PPARα) and Cytosolic Phospholipase A2 (cPLA2), revealing the mechanistic basis for their hepatotoxic effects and potential to impair liver function and human health. These insights enhance our understanding of the potential hepatotoxicity of such fungal toxins and lay a foundation for the assessment of their health risks.


Assuntos
Depsipeptídeos , Hepatócitos , Metabolismo dos Lipídeos , Depsipeptídeos/toxicidade , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Simulação de Acoplamento Molecular , Micotoxinas/toxicidade , Micotoxinas/metabolismo , Sobrevivência Celular/efeitos dos fármacos
6.
Front Nutr ; 9: 837601, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360694

RESUMO

Perchlorate, commonly available in drinking water and food, acts on the iodine uptake by the thyroid affecting lipid metabolism. High-fat diets leading to various health problems continually raise public concern. In the present study, liver lipid metabolism profiles and metabolic pathways were investigated in C57BL/6J mice chronically exposed to perchlorate using targeted metabolomics. Mice were fed a high-fat diet and treated orally with perchlorate at 0.1 mg/kg bw (body weight), 1 mg/kg bw and 10 mg/kg bw daily for 12 weeks. Perchlorate induced disorders of lipid metabolism in vivo and hepatic lipid accumulation confirmed by serum biochemical parameters and histopathological examination. There were 34 kinds of lipid in liver detected by UHPLC-MS/MS and key metabolites were identified by multivariate statistical analysis evaluated with VIP > 1, p-value < 0.05, fold change > 1.2 or < 0.8. Perchlorate low, medium and high dose groups were identified with 11, 7 and 8 significantly altered lipid metabolites compared to the control group, respectively. The results of the metabolic pathway analysis revealed that the differential metabolites classified into different experimental groups contribute to the glycerophospholipid metabolic pathway. These findings provide insights into the effects of perchlorate on lipid metabolism during long-term exposure to high-fat diets and contribute to the evaluation of perchlorate liver toxic mechanisms and health effects.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA