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ObjectiveTo explore the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) in M1 region combined with dorsolateral prefrontal cortex (DLPFC) on electroencephalogram (EEG) θ frequency band amplitude of patients with neuropathic pain (NP) after spinal cord injury. MethodsFrom June, 2022 to June, 2023, 50 NP patients after SCI in Qingdao University Affiliated Hospital were included and divided into M1 region stimulation group (n = 25) and M1 region combined with DLPFC stimulation group (the combined stimulation group, n = 25). M1 region stimulation group received 10 Hz rTMS in the left M1 region, while the combined stimulation group received same stimulation in left M1 region combined with DLPFC, for three weeks. Before and after intervention, the pain was assessed with Short Form of McGill Pain Questionnaire (SF-MPQ), the depression and anxiety status were evaluated using Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA), and the EEG θ frequency band amplitude was recorded to detect the changes of brain electrophysiological activity. ResultsFour cases in M1 region stimulation group, and two cases in the combined stimulation group were dropped. After intervention, the total score of SF-MPQ and the scores of the subscales, the scores of HMMD and HAMA decreased in both groups (|t| > 2.523, P < 0.05). The EEG θ frequency band amplitude significantly reduced in the prefrontal and frontal regions in M1 region stimulation group (|t| > 5.243, P < 0.001), and it also significantly reduced in the prefrontal, frontal regions, central and parietal regions in the combined stimulation group (|t| > 4.630, P < 0.001). All the scores were lower (|t| > 2.270, Z = -1.973, P < 0.05), and the EEG θ frequency band amplitude in the prefrontal, frontal regions, central and parietal regions were lower (P < 0.05) in the combined stimulation group than in M1 region stimulation group. ConclusionHigh frequency rTMS is an effective analgesic method on NP after SCI, which can improve their depression and anxiety symptoms and reduce the EEG θ frequency band amplitude. Compared with M1 region rTMS stimulation, the combination of M1 region and DLPFC rTMS is more effective.
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Objective The ability of working memory (WM) is to temporarily hold and manipulate information for cognitive tasks.The aim of this study was to investigate the causal flow distribution of multi-channel electroencephalographs (EEGs) during Sternberg visual WM task to help understand WM mechanism from the view of neural information transform.Methods Sixteen-channel EEGs were recorded from 8 healthy subjects during Sternberg task,total EEG data for 80 trials were recorded and preprocessed.The EEG powers for each channel were calculated via Fast Fourier transform (FFT).The feature channel was extracted based on the maximum power,and the feature frequency band for WM was determined by time-frequency analysis.The directed transfer function (DTF) and the value of causal flow in EEG feature frequency band were calculated.Results The EEG power focused on θ band (4-8 Hz) and at Fz channel.The maximum value of causal flow was located at Fz,and the first 4 maximum negative values of causal flow were at C3,C4,C5,C6.Conclusions The feature frequency band for WM is the θ band.The causal source (responsible region) is at Fz (frontal region) and the causal sinks are at C3,C4,C5,C6.
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Objective Working memory (WM) is one of important cognitive functions.The aim of this study was to investigate spatial distributions of electroencephalographs (EEGs) power during visual WM task,which may provide support for studying the principal frequency band and critical region related to WM.Methods 32-channel EEGs were recorded from 16 healthy subjects while they perform visual WM task.The data came from 240 trials and the original EEGs were preprocessed.Fourier transform was applied to calculate spatial distributions of EEGs power in the δ,θ,α,β,γfrequency bands and the percentage of each band in the total power.Results The percentages of δ,θ,α,β,γbands in the total power were (22.44±0.86)％,(31.88±0.55)％,(24.66±1.43)％,(13.54±0.64)％,(7.47±0.48)％,respectively.The power in the θ band was significantly higher than those in the other bands (paired t-test,P＜0.001).The θ power was focused in the frontal midline region.Conclusions The principal frequency band related to WM was the θ band and the critical region was the frontal region.
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ABSTRACT Background: Alzheimer's disease is the most leading cause of dementia in the world; the mutation PS-1 E280A alters the gene of the Presenilin-1 and causes an early onset familial Alzheimer's disease. This mutation has been found in large kindred of Antioquia, Colombia. The objective of this study was to find differences revealed by electroencephalogram between healthy subjects and asymptomatic carriers that can be used as clinical markers of the disease in this population. Methods: EEG was recorded in 15 asymptomatic E280A carriers and 15 healthy non carriers during resting and a memory task using 64 channels amplifier. Two conditions in the memory task were analyzed: encoding and retrieval, the process of recording and evocating information, respectively. Power spectrum was calculated in delta (0. 5-4. 0 Hz), theta (4. 0-8. 0 Hz), alpha-1 (8. 0-10. 0 Hz), alpha-2 (10. 0-13. 0 Hz), beta (13. 0-25. 0 Hz) and gamma (25. 0-50 Hz) frequency bands for four regions of interest. Changes were evaluated in different conditions by ANOVA analysis.. Results: In resting condition a significant decrease was found in theta (p=0. 0001) and an increase in alpha-2 frequencies (p=0.037) in carriers compare with controls. During encoding of the memory task theta was significantly lower in carriers compared with controls (p=0. 008) and comparing resting versus retrieval process for each group, there was more theta synchronization in carriers. Conclusions: Early changes in theta frequencies were observed in the EEG recordings, it could be use as clinical markers in this population. Also it seems carriers activate additional cortical regions in order to conserve successful cognitive functions before clinical impairment.
RESUMEN Introducción: la enfermedad de Alzheimer es la principal causa de demencia en el mundo; la mutación PS-1 E280A altera el gen presenilin-1 y causa una variante familiar de la enfermedad que se caracteriza por una aparición temprana. La mutación se ha descubierto en un grupo de familias de Antioquia, Colombia. El objetivo de este estudio fue encontrar diferencias, a partir de registros electroencefalográficos de personas portadores de la mutación en una etapa asintomática y sujetos sanos para evaluar si pueden ser utilizadas como un marcador temprano de la enfermedad en la población portadora de la mutación. Metodología: se realizaron registros EEG en 15 portadores asintomáticos de la mutación E280A y 15 personas sanas no portadoras durante una tarea de memoria y en reposo utilizando un amplificador de 64 canales. En la tarea de memoria se evaluaron dos condiciones: codificación y evocación; el proceso de memorizar y recuperar la información, respectivamente. La potencia espectral fue calculada en las bandas de frecuencia delta (0,5-4,0 Hz), teta (4,0-8,0 Hz), alfa-1 (8,0-10,0 Hz), alfa-2 (10,0-13,0 Hz), beta (13,0-25,0 Hz) y gamma (25,0-50 Hz) para cuatro regiones de interés. Los cambios del espectro fueron evaluados por análisis de varianza ANOVA. Resultados: bajo la condición de reposo se encontró una disminución importante en la potencia de la banda teta (p=0,0001) y un incremento en la banda alfa-2 (p=0,037) en portadores comparados con controles. Durante la tarea de codificación, los portadores mostraron una disminución significativa en la banda teta (p=0,008). Al comparar reposo contra memoria de evocación se encontró una mayor sincronización en teta en los portadores de la mutación. Conclusión: se encontraron cambios tempranos de la potencia en la banda teta que pueden ser utilizados como un marcador clínico de la enfermedad en esta población. Una hipótesis adicional basada en los resultados es que los portadores necesitan ...
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Objective To study the vibration frequencies and resonant peaks of different molecular groups in anti-diabetic drugs and to investigate the absorption spectra of these drugs in the range of terahertz, so as to accurately and efficiently identify similar drugs and provide foundation for understanding the contribution of such vibration in different molecular groups to pharmacology. Methods Using terahertz time domain spectroscopy (THz-TDS), six kinds of similar diabetes pills for treating diabetes mellitus (DM), including gliquidone, glipizide, gliclazide, glimepiride, repaglinide and metformin were tested to obtain their absorption spectra from 0.3~3.0 THz. Support vector machines (SVM) method was employed to separate these anti-diabetic drugs by selecting the experimental data from 1.5~2.0 THz. Results For gliquidone, glipizide, gliclazide, and glimepiride, an obvious resonance peak was found at 1.37 THz. According to the THz spectra, repaglinide and metformin could be easily separated from sulfonylurea drugs. Furthermore, with the help of SVM, the accuracy of discrimination for four kinds of sulfonylurea could reach 100%. Conclusions THz technology, as a new testing method, shall play a positive role in the drugs for their identification, quality control and distinguishing their chemical bonds/functional group.