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1.
Neuroscience Bulletin ; (6): 147-156, 2024.
Article in English | WPRIM | ID: wpr-1010679

ABSTRACT

The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation. This stereoelectroencephalography (SEEG) study investigated how the dorsolateral prefrontal cortex (DLPFC) interacts with the hippocampus in the online processing of sequential information. Twenty patients with epilepsy (eight women, age 27.6 ± 8.2 years) completed a line ordering task with SEEG recordings over the DLPFC and the hippocampus. Participants showed longer thinking times and more recall errors when asked to arrange random lines clockwise (random trials) than to maintain ordered lines (ordered trials) before recalling the orientation of a particular line. First, the ordering-related increase in thinking time and recall error was associated with a transient theta power increase in the hippocampus and a sustained theta power increase in the DLPFC (3-10 Hz). In particular, the hippocampal theta power increase correlated with the memory precision of line orientation. Second, theta phase coherences between the DLPFC and hippocampus were enhanced for ordering, especially for more precisely memorized lines. Third, the theta band DLPFC → hippocampus influence was selectively enhanced for ordering, especially for more precisely memorized lines. This study suggests that theta oscillations may support DLPFC-hippocampal interactions in the online processing of sequential information.


Subject(s)
Adult , Female , Humans , Young Adult , Male , Epilepsy , Hippocampus , Memory, Short-Term , Mental Recall , Prefrontal Cortex , Theta Rhythm
2.
Journal of Biomedical Engineering ; (6): 1142-1151, 2023.
Article in Chinese | WPRIM | ID: wpr-1008944

ABSTRACT

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment, with the predominant clinical diagnosis of spatial working memory (SWM) deficiency, which seriously affects the physical and mental health of patients. However, the current pharmacological therapies have unsatisfactory cure rates and other problems, so non-pharmacological physical therapies have gradually received widespread attention. Recently, a novel treatment using 40 Hz light flicker stimulation (40 Hz-LFS) to rescue the cognitive function of model animals with AD has made initial progress, but the neurophysiological mechanism remains unclear. Therefore, this paper will explore the potential neural mechanisms underlying the modulation of SWM by 40 Hz-LFS based on cross-frequency coupling (CFC). Ten adult Wistar rats were first subjected to acute LFS at frequencies of 20, 40, and 60 Hz. The entrainment effect of LFS with different frequency on neural oscillations in the hippocampus (HPC) and medial prefrontal cortex (mPFC) was analyzed. The results showed that acute 40 Hz-LFS was able to develop strong entrainment and significantly modulate the oscillation power of the low-frequency gamma (lγ) rhythms. The rats were then randomly divided into experimental and control groups of 5 rats each for a long-term 40 Hz-LFS (7 d). Their SWM function was assessed by a T-maze task, and the CFC changes in the HPC-mPFC circuit were analyzed by phase-amplitude coupling (PAC). The results showed that the behavioral performance of the experimental group was improved and the PAC of θ-lγ rhythm was enhanced, and the difference was statistically significant. The results of this paper suggested that the long-term 40 Hz-LFS effectively improved SWM function in rats, which may be attributed to its enhanced communication of different rhythmic oscillations in the relevant neural circuits. It is expected that the study in this paper will build a foundation for further research on the mechanism of 40 Hz-LFS to improve cognitive function and promote its clinical application in the future.


Subject(s)
Humans , Adult , Rats , Animals , Memory, Short-Term/physiology , Rats, Wistar , Neurodegenerative Diseases , Hippocampus , Prefrontal Cortex
3.
Neuroscience Bulletin ; (6): 275-289, 2022.
Article in English | WPRIM | ID: wpr-929084

ABSTRACT

How to quickly predict an individual's behavioral choices is an important issue in the field of human behavior research. Using noninvasive electroencephalography, we aimed to identify neural markers in the prior outcome-evaluation stage and the current option-assessment stage of the chicken game that predict an individual's behavioral choices in the subsequent decision-output stage. Hierarchical linear modeling-based brain-behavior association analyses revealed that midfrontal theta oscillation in the prior outcome-evaluation stage positively predicted subsequent aggressive choices; also, beta oscillation in the current option-assessment stage positively predicted subsequent cooperative choices. These findings provide electrophysiological evidence for the three-stage theory of decision-making and strengthen the feasibility of predicting an individual's behavioral choices using neural oscillations.


Subject(s)
Aggression/physiology , Brain , Electroencephalography , Interpersonal Relations
4.
Biol. Res ; 55: 37-37, 2022. ilus, tab
Article in English | LILACS | ID: biblio-1429902

ABSTRACT

BACKGROUND: Diabetes mellitus (DM) has glucose variability that is of such relevance that the appearance of vascular complications in patients with DM has been attributed to hyperglycemic and dysglycemic events. It is known that T1D patients mainly have glycemic variability with a specific oscillatory pattern with specific circadian characteristics for each patient. However, it has not yet been determined whether an oscillation pattern represents the variability of glycemic in T2D. This is why our objective is to determine the characteristics of glycemic oscillations in T2D and generate a robust predictive model. RESULTS: Showed that glycosylated hemoglobin, glycemia, and body mass index were all higher in patients with T2D than in controls (all p < 0.05). In addition, time in hyperglycemia and euglycemia was markedly higher and lower in the T2D group (p < 0.05), without significant differences for time in hypoglycemia. Standard deviation, coefficient of variation, and total power of glycemia were significantly higher in the T2D group than Control group (all p < 0.05). The oscillatory patterns were significantly different between groups (p = 0.032): the control group was mainly distributed at 2-3 and 6 days, whereas the T2D group showed a more homogeneous distribution across 2-3-to-6 days. CONCLUSIONS: The predictive model of glycemia showed that it is possible to accurately predict hyper- and hypo-glycemia events. Thus, T2D patients exhibit specific oscillatory patterns of glycemic control, which are possible to predict. These findings may help to improve the treatment of DM by considering the individual oscillatory patterns of patients.


Subject(s)
Humans , Diabetes Mellitus, Type 2/complications , Hypoglycemia , Blood Glucose , Glucose
5.
Rev. colomb. ciencias quim. farm ; 50(3)Sep.-Dec. 2021.
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-1535804

ABSTRACT

Introdução: a olanzapina é um dos fármacos antipsicóticos benzodiazepínicos mais usados no mundo. Apesar da sua eficiência, em concentrações excessivas, ela sói ser tóxica, como quaisquer outros fármacos desta classe. Assim, neste trabalho, se avaliou, pela primeira vez, a possibilidade da detecção eletroquímica do fármaco olanzapina, assistida pelo compósito do oxihidróxido de cobalto (III), emparelhado com o dióxido, com um corante esquaraínico. Método: o modelo matemático trivariante correspondente inclui dois cenários de oxidação do fármaco, possíveis para o caso, incluindo a eletropolimerização indireta da molécula da benzodiazepina condensada, bem como a oxidação do fármaco pelo átomo do enxofre. Este modelo tem sido desenvolvido e analisado mediante a teoria de estabilidade linear e análise de bifurcações. Resultados e discussão: a análise do modelo há mostrado que a hibridez do mecanismo do processo eletroanalítico, aliada à composição e descomposição dos compostos iônicos aquando da sua realização, aumenta a probabilidade da ocorrência do comportamento oscilatório, em relação ao caso mais simples e mais comum. No entretanto, a instabilidade oscilatória se realiza nos valores dos parâmetros, que estão além do limite de detecção. Por sua vez, o estado estacionário se obtém e se mantém facilmente, indicando um processo eletroanalítico eficiente, controlado pela difusão do analito. Conclusões: trata-se de um processo eletroanalítico eficiente, em que o composto de cobalto funciona como substância ativa, e o corante desempenha o papel de mediador


SUMMARY Introduction: olanzapine is one of the most used antipsychotic drugs in the world. Although it is efficient, it may be toxic in excess. Therefore, in this work the possibility of olanzapine electrochemical determination over an electrode, modified by the cobalt (III) oxyhydroxide in pair with its dioxide in a composite with squaraine dye. Methods: the trivariant correspondent mathematical model includes two scenarios of the drug oxidation, possible for the case, including the indirect electropolymerization of the condensed benzodiazepine molecule, like also its oxidation by sulfur atom. This model has been developed and analyzed by means of stability theory and bifurcation analysis. Results and discussion: the analysis of the model has shown that the mechanism hybridity of the electroanalytical process, alongside with the formation and decomposition of ionic compounds during its realization, augments the possibility for the oscillatory behavior realization, relatively to the simplest and commonest case. Nevertheless, the oscillatory instability is realized in parameter values far beyond the detection limit. On the other hand, the stable steady-state is easy to obtain and maintain, indicating an efficient electroanalytical process, controlled by the analyte diffusion. Conclusions: the electroanalytical process is efficient. The cobalt compound is acting as an active substance, and the dye is the mediator.


Introducción: la olanzapina es uno de los fármacos antipsicóticos más utilizados en el mundo. Aunque es eficaz, puede resultar tóxico en exceso. Por tanto, en este trabajo se plantea la posibilidad de la determinación electroquímica de olanzapina sobre un electrodo, modificado por el oxihidróxido de cobalto (III) en pareja con su dióxido en un composito con colorante de escuaraína. Métodos: el modelo matemático correspondiente incluye dos escenarios de oxidación del fármaco, posibles para el caso, que incluyen la electropolimerización indirecta de la molécula de benzodiazepina condensada, así como su oxidación por átomo de azufre. Este modelo ha sido desarrollado y analizado mediante teoría de estabilidad y análisis de bifurcación. Resultados y discusión: el análisis del modelo ha demostrado que el mecanismo de hibridación del proceso electroanalítico, junto con la formación y descomposición de compuestos iónicos durante su realización, aumenta la posibilidad de realización del comportamiento oscilatorio, relativamente al caso más simple y común. Sin embargo, la inestabilidad oscilatoria se realiza en valores de parámetros mucho más allá del límite de detección. Por otro lado, el estado estacionario estable es fácil de obtener y mantener, lo que indica un proceso electroanalítico eficiente, controlado por la difusión del analito. Conclusiones: el proceso electroanalítico es eficiente. El compuesto de cobalto actúa como sustancia activa y el colorante es el mediador.

6.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1389775

ABSTRACT

Resumen Nuestro cerebro tiene diferentes estados de funcionamiento, uno de ellos es la ausencia de estimulación auditiva o estado de silencio. Para evaluar la capacidad de detección de períodos de silencio auditivo se pueden utilizar diversas pruebas, incluyendo evaluaciones conductuales y electrofisiológicas. En esta última línea existen numerosos estudios que han caracterizado la respuesta cerebral al silencio mediante oscilaciones cerebrales y potenciales evocados con silencio. Esta área promete una importante aplicabilidad clínica, por ejemplo, en patologías como tinnitus, condición en la que no existe el estado de silencio, en donde se cree que la evaluación de respuestas cerebrales al silencio podría surgir como un nuevo marcador o elemento diagnóstico. En este artículo se presenta una revisión de los distintos métodos utilizados para evaluar respuestas cerebrales al silencio en modelos animales y en humanos.


Abstract The brain has different states of operation, one of them is the absence of auditory stimulation or silent states. To assess the capacity to detect auditory silent periods, various tests have been developed, including behavioral and electrophysiological evaluations. Brain responses to silence can be evaluated with brain oscillations and evoked potentials. This area promises important clinical applicability, for example, in pathologies like tinnitus, a condition in which there is no silent state, where it is believed that the evaluation of brain responses to silence could emerge as a new marker or diagnostic element. In this article we review different methods used for assessing brain responses to sound in animal models and humans.

7.
Rev. colomb. ciencias quim. farm ; 50(1): 205-216, Jan.-Apr. 2021. graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1347320

ABSTRACT

RESUMEN Objetivo: En este trabajo se realiza, por primera vez, la evaluación teórica de la posibilidad de la detección electroanalítica de salvarsano, fármaco antisifilítico. El oxihidróxido de cobalto, en su compuesto con el colorante escuárico, se usa como modificador de electrodo. Metodología: Mediante el análisis de estabilidad, se ha confirmado su eficiencia en los procesos de detección de salvarsano. La linearidad de dependencia entre el parámetro electroquímico y la concentración del fármaco se obtiene y se mantiene fácilmente. Conclusión: Las inestabilidades oscilatoria y monotónica se realizan en el sistema, causadas por las influencias de las etapas electroquímicas a las capacitancias de la doble capa eléctrica (DCE).


SUMMARY Aim: In this work, the theoretical evaluation of the electroanalytical detection of antisyphilitic drug salvarsan is given for the first time. Cobalt oxyhydroxide in a composite with the squaraine dye is used as electrode modifier. Methodology: By means of the stability analysis the efficiency of the salvarsan determination is confirmed. The linearity of the dependence between the electrochemical parameter and drug concentration is easily obtained and maintained. Conclusion: The oscillatory and monotonic instabilities are realized in this system, being caused by the electrochemical stages' influences to the double electric layer (DEL).


RESUMO Objetivo: neste trabalho, a avaliação teórica da detecção eletroanalítica do antissifilítico salvarsan é feita pela primeira vez. O oxihidróxido de cobalto em um composto com o corante esquaraína é usado como modificador de eletrodo. Metodologia: por meio da análise de estabilidade é confirmada a eficiência da determinação de salvarsan. A linearidade da dependência entre o parâmetro eletroquímico e a concentração do fármaco é facilmente obtida e mantida. Conclusão: as instabilidades osci-latórias e monotônicas são percebidas neste sistema, sendo causadas pelas influências dos estágios eletroquímicos sobre a dupla camada elétrica (DEL).

8.
Asian Pacific Journal of Tropical Medicine ; (12): 552-558, 2019.
Article in Chinese | WPRIM | ID: wpr-951198

ABSTRACT

To explore the relationship between climate variables and enteric fever in the city of Ahmedabad and report preliminary findings regarding the influence of El Niño Southern Oscillations and Indian Ocean Dipole over enteric fever incidence. Method: A total of 29 808 Widal positive enteric fever cases reported by the Ahmedabad Municipal Corporation and local climate data in 1985-2017 from Ahmedabad Meteorology Department were analysed. El Niño, La Niña, neutral and Indian Ocean Dipole years as reported by the National Oceanic and Atmospheric Administration for the same period were compared for the incidence of enteric fever. Results: Population-normalized average monthly enteric fever case rates were the highest for El Niño years (25.5), lower for La Niña years (20.5) and lowest for neutral years (17.6). A repeated measures ANOVA analysis showed no significant difference in case rates during the three yearly El Niño Southern Oscillations categories. However, visual profile plot of estimated marginal monthly means showed two distinct characteristics: an early rise and peaking of cases in the El Niño and La Niña years, and a much more restrained rise without conspicuous peaks in neutral years. Further analysis based on monthly El Niño Southern Oscillations categories was conducted to detect differences in median monthly case rates. Median case rates in strong and moderate El Niño months and strong La Niña months were significantly dissimilar from that during neutral months (P<0.001). Conclusions: El Niño Southern Oscillations events influence the incidence of enteric fever cases in Ahmedabad, and further investigation from more cities and towns is required.

9.
Asian Pacific Journal of Tropical Medicine ; (12): 552-558, 2019.
Article in English | WPRIM | ID: wpr-846793

ABSTRACT

To explore the relationship between climate variables and enteric fever in the city of Ahmedabad and report preliminary findings regarding the influence of El Niño Southern Oscillations and Indian Ocean Dipole over enteric fever incidence. Method: A total of 29 808 Widal positive enteric fever cases reported by the Ahmedabad Municipal Corporation and local climate data in 1985-2017 from Ahmedabad Meteorology Department were analysed. El Niño, La Niña, neutral and Indian Ocean Dipole years as reported by the National Oceanic and Atmospheric Administration for the same period were compared for the incidence of enteric fever. Results: Population-normalized average monthly enteric fever case rates were the highest for El Niño years (25.5), lower for La Niña years (20.5) and lowest for neutral years (17.6). A repeated measures ANOVA analysis showed no significant difference in case rates during the three yearly El Niño Southern Oscillations categories. However, visual profile plot of estimated marginal monthly means showed two distinct characteristics: an early rise and peaking of cases in the El Niño and La Niña years, and a much more restrained rise without conspicuous peaks in neutral years. Further analysis based on monthly El Niño Southern Oscillations categories was conducted to detect differences in median monthly case rates. Median case rates in strong and moderate El Niño months and strong La Niña months were significantly dissimilar from that during neutral months (P<0.001). Conclusions: El Niño Southern Oscillations events influence the incidence of enteric fever cases in Ahmedabad, and further investigation from more cities and towns is required.

10.
Journal of Biomedical Engineering ; (6): 320-324, 2019.
Article in Chinese | WPRIM | ID: wpr-774204

ABSTRACT

Selective attention promotes the perception of brain to outside world and coordinates the allocation of limited brain resources. It is a cognitive process which relies on the neural activities of attention-related brain network. As one of the important forms of brain activities, neural oscillations are closely related to selective attention. In recent years, the relationship between selective attention and neural oscillations has become a hot issue. The new method that using external rhythmic stimuli to influence neural oscillations, i.e., neural entrainment, provides a promising approach to investigate the relationship between selective attention and neural oscillations. Moreover, it provides a new method to diagnose and even to treat the attention dysfunction. This paper reviewed the research status on the relationship between selective attention and neural oscillations, and focused on the application prospects of neural entrainment in revealing this relationship and diagnosing, even treating the attention dysfunction.


Subject(s)
Humans , Attention , Brain , Physiology , Neurons , Physiology
11.
Food Sci. Technol (SBCTA, Impr.) ; 37(4): 673-680, Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-892222

ABSTRACT

Abstract The degenerative effect of temperature fluctuations during storage time is a critical condition that needs to be quantitatively characterized in products where drip losses are appreciable. In this work, real storage conditions were reproduced using freezers modified to cause 3 levels of temperature fluctuation (± 0, ± 3, ± 5; ± 7) during storage of Tilapia (Oreochromis sp), at temperature of -18 °C. The fast frozen tilapia muscle (freezing cabinet) was chosen to quantify the growth of ice crystals according to temperature fluctuations. The identification of crystals in the optical microscope as well as histological treatments and measurements using specific software has shown that the growth of ice crystals in the first days of storage follows an asymptote, whose final value is conditioned only by the level of temperature fluctuations regardless of initial diameter, which begins storage. It has also been found that the growth of crystals formed during rapid freezing rapidly develops according to temperature fluctuations to which the product has been subjected. This work also identified statistically significant differences in the equivalent diameter of crystals formed at the four proposed levels of temperature fluctuation with significance level of p < 0.05.

12.
Journal of Korean Dental Science ; : 45-52, 2017.
Article in English | WPRIM | ID: wpr-764776

ABSTRACT

Calcium has versatile roles in diverse physiological functions. Among these functions, intracellular Ca²⁺ plays a key role during the secretion of salivary glands. In this review, we introduce the diverse cellular components involved in the saliva secretion and related dynamic intracellular Ca²⁺ signals. Calcium acts as a critical second messenger for channel activation, protein translocation, and volume regulation, which are essential events for achieving the salivary secretion. In the secretory process, Ca²⁺ activates K⁺ and Cl⁻ channels to transport water and electrolyte constituting whole saliva. We also focus on the Ca²⁺ signals from intracellular stores with discussion about detailed molecular mechanism underlying the generation of characteristic Ca²⁺ patterns. In particular, inositol triphosphate signal is a main trigger for inducing Ca²⁺ signals required for the salivary gland functions. The biphasic response of inositol triphosphate receptor and Ca²⁺ pumps generate a self-limiting pattern of Ca²⁺ efflux, resulting in Ca²⁺ oscillations. The regenerative Ca²⁺ oscillations have been detected in salivary gland cells, but the exact mechanism and function of the signals need to be elucidated. In future, we expect that further investigations will be performed toward better understanding of the spatiotemporal role of Ca²⁺ signals in regulating salivary secretion.


Subject(s)
Calcium Signaling , Calcium , Chloride Channels , Inositol , Inositol 1,4,5-Trisphosphate Receptors , Protein Transport , Saliva , Salivary Glands , Salivation , Second Messenger Systems , Secretory Pathway , Water
13.
Chinese Journal of Applied Clinical Pediatrics ; (24): 881-886, 2017.
Article in Chinese | WPRIM | ID: wpr-620344

ABSTRACT

Electrical status epilepticus in sleep (ESES) indicates a special electroencephalographic pattern showing sleep-induced continuous paroxysmal discharges of spike-wave complexes.ESES can be seen in a series of epileptic syndromes in children characterized by seizures,ESES and cognitive impairment,including epilepsy with continuous spikes and waves during slow sleep,Landau Kleffner syndrome,typical and atypical benign childhood epilepsy with centro-temporal spikes.Though the mechanism generating ESES remains elusive,great advances in several aspects,such as genetic studies (GRIN2A,copy number variations,ect.),high-frequency oscillations and brain networks have been achieved.Treatment for ESES related disorders should focus on both epileptic seizures and ESES,and the introduction of appropriate antiepileptic drugs or other strategies like hormone therapy should be considered to furthest eliminate epileptic seizures and protect cognitive function.

14.
Clinical and Experimental Reproductive Medicine ; : 15-21, 2017.
Article in English | WPRIM | ID: wpr-165799

ABSTRACT

OBJECTIVE: The aims of this study were to investigate whether fertilization could induce the resumption of meiosis in mouse oocytes arrested at metaphase I (MI) after in vitro maturation (IVM), and to investigate the effect of Ca²⁺ chelator treatment at the time of fertilization on the transition from MI to metaphase II (MII). METHODS: MII-stage and arrested MI-stage mouse oocytes after IVM were fertilized, and then embryonic development was monitored. Blastocysts from each group were transferred into 2.5 days post-coitum pseudo-pregnant ICR mice. MI oocytes after IVM were treated with a Ca²⁺ chelator to investigate the effect of Ca²⁺ oscillations on their maturation. RESULTS: As insemination time increased, the number of oocytes in the MI group that reached the MII stage also increased. The blastocyst rates and total cell numbers in the MII group were significantly higher than in the MI group. No pregnancy occurred in the MI group, but 10 pregnancies were achieved (10 of 12) in the MII group. The proportion of MI oocytes that matured to MII oocytes after fertilization was significantly higher in the non-treated group than in the Ca²⁺ chelator-treated group. CONCLUSION: The findings that a higher proportion of MI-arrested oocytes progressed to MII after fertilization and that the MI-to-MII transition was blocked by Ca2+ chelator treatments before fertilization indicate that the maturation of MI oocytes to MII oocytes is associated with intracellular Ca²⁺ oscillations driven by fertilization.


Subject(s)
Animals , Female , Mice , Pregnancy , Blastocyst , Calcium Signaling , Cell Count , Embryonic Development , Fertilization , In Vitro Oocyte Maturation Techniques , In Vitro Techniques , Insemination , Meiosis , Metaphase , Mice, Inbred ICR , Oocytes , Spermatozoa
15.
Malaysian Journal of Medical Sciences ; : 5-16, 2016.
Article in English | WPRIM | ID: wpr-625264

ABSTRACT

Transcranial magnetic stimulation (TMS) is a non-invasive, non-pharmacological technique that is able to modulate cortical activity beyond the stimulation period. The residual aftereffects are akin to the plasticity mechanism of the brain and suggest the potential use of TMS for therapy. For years, TMS has been shown to transiently improve symptoms of neuropsychiatric disorders, but the underlying neural correlates remain elusive. Recently, there is evidence that altered connectivity of brain network dynamics is the mechanism underlying symptoms of various neuropsychiatric illnesses. By combining TMS and electroencephalography (EEG), the functional connectivity patterns among brain regions, and the causal link between function or behaviour and a specific brain region can be determined. Nonetheless, the brain network connectivity are highly complex and involve the dynamics interplay among multitude of brain regions. In this review article, we present previous TMS-EEG co-registration studies, which explore the functional connectivity patterns of human cerebral cortex. We argue the possibilities of neural correlates of long-term potentiation/ depression (LTP-/LTD)-like mechanisms of synaptic plasticity that drive the TMS aftereffects as shown by the dissociation between EEG and motor evoked potentials (MEP) cortical output. Here, we also explore alternative explanations that drive the EEG oscillatory modulations post TMS. The precise knowledge of the neurophysiological mechanisms underlying TMS will help characterise disturbances in oscillatory patterns, and the altered functional connectivity in neuropsychiatric illnesses.

16.
International Journal of Biomedical Engineering ; (6): 134-139,148, 2016.
Article in Chinese | WPRIM | ID: wpr-604633

ABSTRACT

Objective Temporal lobe epilepsy (TLE),frequently accompanied by working memory dysfunction,is an important form of adult epilepsy syndrome.Study on neural mechanisms of TLE with working memory dysfunction has important scientific value and clinical significance.Theta oscillations are synchronous activity of the brain in the 4-8 Hz frequency range.It is well recognized that there is a close relationship between the theta oscillations and working memory behavior.TLE patients with working memory dysfunction were taken as the research subjects,and the theta oscillations absence in TLE with working memory behavioral disorder was carried out,which provide the reference for further research into the neural mechanisms of TLE with working memory dysfunction.Methods The 34-channel electroencephalographs (EEGs) were recorded from TLE group (18 TLE patients) and control groups (18 healthy subjects) while subjects were performing visual working memory (delayed matching-tosample) tasks.The EEGs during the 3 s delay period was analyzed as experimental data.Fourier transform was used to assess the EEGs spectrum.The channel with the strongest spectrum was selected as the feature channel.Short-time Fourier transform algosiths was employed to calculate the time-frequency representation of the feature channel for the TLE and control groups.Frequency band with the strongest spectrum was selected for control group as the feature frequency band in working memory.Then,the topographical maps of the feature frequency band spectrum were calculated for the TLE and control groups.Results Compared with the control group,the working memnory behavioral performance of the TLE group was lower:accuracy of the TLE group was significantly lower than that of the control group (P<0.05),and reaction time of the TLE group was significantly longer than that of the control group (P<0.001).The feature channel in working memnory was frontal midline (Fz) and the feature frequency band was theta band.The Fz spectrum of the feature frequency for TLE was lower than that for control (P<0.05).The frontal spectrum (seven channels) of the feature frequency for TLE was lower than that of control (P<0.01).Conclusions Theta oscillations for TLE with working memory behavioral disorder is absent,which maybe one of the possible neural mechanism of TLE with working memory dysfunction.

17.
Journal of Clinical Neurology ; : 107-114, 2016.
Article in English | WPRIM | ID: wpr-166852

ABSTRACT

BACKGROUND AND PURPOSE: Periodic limb movements (PLM) during sleep (PLMS) are associated with cortical and cardiovascular activation. Changes in cerebral hemodynamics caused by cortical activity can be measured using near-infrared spectroscopy (NIRS). We investigated oscillatory components of cerebral hemodynamics during PLM and different sleep stages in restless legs syndrome (RLS) patients with PLMS. METHODS: Four female RLS patients with PLMS, and four age- and sex-matched normal controls were included. PLM and sleep stages were scored using polysomnography, while the spontaneous cerebral hemodynamics was measured by NIRS. The phase and amplitude of the cerebral oxyhemoglobin concentration [HbO] and the deoxyhemoglobin concentration [Hb] low-frequency oscillations (LFOs) were evaluated during each sleep stage [waking, light sleep (LS; stages N1 and N2), slow-wave sleep (stage N3), and rapid eye movement (REM) sleep]. In RLS patients with PLMS, the cerebral hemodynamics during LS was divided into LS with and without PLM. RESULTS: The cerebral hemodynamics activity varied among the different sleep stages. There were changes in phase differences between [HbO] and [Hb] LFOs during the different sleep stages in the normal controls but not in the RLS patients with PLMS. The [HbO] and [Hb] LFO amplitudes were higher in the patient group than in controls during both LS with PLM and REM sleep. CONCLUSIONS: The present study has demonstrated the presence of cerebral hemodynamics disturbances in RLS patients with PLMS, which may contribute to an increased risk of cerebrovascular events.


Subject(s)
Female , Humans , Extremities , Hemodynamics , Oxyhemoglobins , Polysomnography , Restless Legs Syndrome , Sleep Stages , Sleep, REM , Spectroscopy, Near-Infrared
18.
Rev. colomb. ciencias quim. farm ; 44(2): 148-161, mayo-ago. 2015. ilus, graf, mapas, tab
Article in Portuguese | LILACS | ID: lil-765582

ABSTRACT

A oxidação eletrocatalítica de paracetamol, acompanhada ou não pela eletropolimerização do próprio, sobre poli(azul da anilina) foi descrita matematicamente (usando a teoria de estabilidade linear e análise de bifurcações). Para o comportamento do composto foi sugerido o mecanismo que concorda com os dados experimentais e com os cálculos teóricos. Foi investigada também a dependência do desempenho do polímero e do comportamento do composto do pH.


The electrocatalytic paracetamol oxidation over poly(aniline blue), accompanied or not by its electropolymerization, has been described mathematically (using the linear stability theory and bifurcation analysis). For the compound' s behavior a mechanism, according with the experimental data and theoretical calculations, has been suggested. Also the pH-dependence of the work of the polymer and the compound' s behavior has been investigated.

19.
Rev. colomb. ciencias quim. farm ; 44(2): 208-219, mayo-ago. 2015. ilus, graf, mapas, tab
Article in Portuguese | LILACS | ID: lil-765586

ABSTRACT

Para o processo da eletrooxidação da hidrazina sobre a camada do composto carbonílico derivado de ferroceno, foi sugerido o mecanismo do desempenhoeletroanalítico. Para ele, também foi desenvolvido e analisado (por meio da teoria de estabilidade lineal e análise de bifurcações) o modelo matemático, capaz de descrever os processos no sistema. Os resultados da modelagem foram comparados com os experimentais, bem como com os teóricos, observados para sistemas análogos.


For the process of hydrazine electrooxidation over the layer of ferrocene-carbonylic derivative, the electroanalytic functionmechanism has been suggested. Also there has been developed and analyzed (by means of linear stability theory and bifurcation analysis) the mathematical model, capable to describe the processes in the system. The results of the modeling have been compared with experimental and theoretical for analogous systems.

20.
Chinese Journal of Applied Clinical Pediatrics ; (24): 892-894, 2015.
Article in Chinese | WPRIM | ID: wpr-468173

ABSTRACT

High-frequency oscillations are used more and more widely on localizing epileptogenic zone and evaluating outcome as the surgery on epilepsy cases are increasing and the technique of electroencephalogram (EEG) are being improved.High-frequency oscillations are recorded by intracranial electrodes on most previous studies.However,recent reports describing high-frequency oscillations on scalp EEG recordings have created significant interest.Scalp high-frequency EEG provides a safe,non-invasive and simple method for us to study the special brain electrical activity.This paper summary the clinical applications and some questions on scalp high-frequency EEG.

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