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Microwave absorbing materials (MAMs) characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications. Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions, while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals. Herein, we have successfully implemented compositional and structural engineering to fabricate hollow SiC/C microspheres with controllable composition. The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites. The formation of hollow structure not only favors lightweight feature, but also generates considerable contribution to microwave attenuation capacity. With the synergistic effect of composition and structure, the optimized SiC/C composite exhibits excellent performance, whose the strongest reflection loss intensity and broadest effective absorption reach - 60.8 dB and 5.1 GHz, respectively, and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies. In addition, the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.
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Forest management may lead to changes in soil carbon and its stability, and the effects are variable owing to the differences in management methods. Our study aimed to determine the impacts of different forest management practices on soil carbon pools and their stability. We chose a natural oak forest, where different forest-management strategies have been practiced. Forest management strategies included cultivating target trees by removing interference trees (CNFM), optimizing the forest spatial structure by the structural parameters (SBFM), reducing the stand density by harvesting timber (SFCS), and using unmanaged forests as controls (NT). Topsoil (depth of 0-10 cm) was collected after eight years of forest management. Soil organic carbon (SOC), labile organic carbon components and the microbial community were determined, and SOC chemical compositions were assessed by nuclear magnetic resonance. The CNFM and SFCS strategies had smaller dissolved organic carbon contents than the NT and SBFM strategies, and the CNFM strategy increased the ratio of alkyl C and o-alkyl C, indicating that the SOC was more stable. Forest management strategies changed the SOC and its labile C pool by adjusting the soil total nitrogen,ß-glucosidase, cellobiohydrolase, fine-root carbon and fungal operational taxonomic units, and the SOC chemical compositions were influenced by the number of fungal species. These findings suggest that the soil organic carbon decreased, but its stability increased in the natural forest under the practice of cultivating target trees by removing interference trees. The SOC pools could be regulated by soil nitrogen, enzyme activity, fine roots, and fungi, while soil fungi could affect SOC stability.
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Temporal lobe epilepsy (TLE) is characterized as an impaired ability of learning and memory with periodic and unpredictable seizures. Status epilepticus (SE) is one of the main causes of TLE. Neuroinflammation and oxidative stress are directly involved in epileptogenesis and neurodegeneration, promoting chronic epilepsy and cognitive deficit. Previous studies have shown that ursolic acid (UA) represses inflammation and oxidative stress, contributing to neuroprotection. Herein, we demonstrated that UA treatment alleviated seizure behavior and cognitive impairment induced by epilepsy. Moreover, UA treatment rescued hippocampal neuronal damage, aberrant neurogenesis, and ectopic migration, which are commonly accompanied by epilepsy occurrence. Our study also demonstrated that UA treatment remarkably suppressed the SE-induced neuroinflammation, evidenced by activated microglial cells and decreased inflammation factors, including TNF-α and IL-1ß. Likewise, the expression levels of oxidative stress damage markers and oxidative phosphorylation (OXPHOS) enzyme complexes of mitochondria were also remarkably downregulated following the UA treatment, suggesting that UA suppressed the damage caused by the high oxidative stress and the defect mitochondrial function induced by SE. Furthermore, UA treatment attenuated GABAergic interneuron loss. In summary, our study clarified the notable anti-seizure and neuroprotective properties of UA in pilocarpine-induced epileptic rats, which is mainly achieved by abilities of anti-inflammation and anti-oxidation. Our study indicates the potential advantage of UA application in ameliorating epileptic sequelae.
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BackgroundSince December 2019, a cluster of coronavirus disease 2019 (COVID-19) occurred in Wuhan, Hubei Province, China and spread rapidly from China to other countries. In-hospital mortality are high in severe cases and cardiac injury characterized by elevated cardiac troponin are common among them. The mechanism of cardiac injury and the relationship between cardiac injury and in-hospital mortality remained unclear. Studies focused on cardiac injury in COVID-19 patients are scarce. ObjectivesTo investigate the association between cardiac injury and in-hospital mortality of patients with confirmed or suspected COVID-19. MethodsDemographic, clinical, treatment, and laboratory data of consecutive confirmed or suspected COVID-19 patients admitted in Wuhan No.1 Hospital from 25th December, 2019 to 15th February, 2020 were extracted from electronic medical records and were retrospectively reviewed and analyzed. Univariate and multivariate Cox regression analysis were used to explore the risk factors associated with in-hospital death. ResultsA total of 110 patients with confirmed (n=80) or suspected (n=30) COVID-19 were screened and 48 patients (female 31.3%, mean age 70.58{+/-}13.38 year old) among them with high-sensitivity cardiac troponin I (hs-cTnI) test within 48 hours after admission were included, of whom 17 (17/48, 35.4%) died in hospital while 31 (31/48, 64.6%) were discharged or transferred to other hospital. High-sensitivity cardiac troponin I was elevated in 13 (13/48, 27.1%) patents. Multivariate Cox regression analysis showed pulse oximetry of oxygen saturation (SpO2) on admission (HR 0.704, 95% CI 0.546-0.909, per 1% decrease, p=0.007), elevated hs-cTnI (HR 10.902, 95% 1.279-92.927, p=0.029) and elevated d-dimer (HR 1.103, 95%CI 1.034-1.176, per 1mg/L increase, p=0.003) on admission were independently associated with in-hospital mortality. ConclusionsCardiac injury defined by hs-cTnI elevation and elevated d-dimer on admission were risk factors for in-hospital death, while higher SpO2 could be seen as a protective factor, which could help clinicians to identify patients with adverse outcome at the early stage of COVID-19.
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In polymer solar cells (PSCs), it is difficult for twisted conjugated polymers to achieve high power-conversion efficiency (PCE) as donors due to their low charge carrier mobilities and poor bulk heterojunction morphologies. In this work, a new twisted conjugated polymer (P3TCO-1) with excellent solubilities (above 30 mg mL-1 ) in common organic solvents at room temperature is reported. UV-visible absorption spectra and cyclic voltammetry indicate that P3TCO-1 has a wide optical bandgap of 1.90 eV and deep HOMO level of -5.39 eV. In binary PSCs, P3TCO-1:ITIC-based device shows a PCE of 10.11%, with JSC of 17.05 mA cm-2 and FF of 62.89%; P3TCO-1:PC71 BM-based device gives a PCE of 6.67% with JSC of 12.31 mA cm-2 and FF of 58.00%. When the two acceptors of ITIC and PC71 BM are combined, the twisted P3TCO-1-based ternary PSCs exhibit a significantly boosted PCE of up to 11.41%, with a simultaneously improved JSC of 18.16 mA cm-2 and FF of 66.78%. These results can guide the improvement of PCE for twisted conjugated polymer-based PSCs.
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Ácidos Carboxílicos/química , Polímeros/química , Energia Solar , Tiofenos/química , Fontes de Energia Elétrica , Estrutura Molecular , Polímeros/síntese química , Teoria QuânticaRESUMO
Objective@#To evaluate the positive correlation between excessive screen-watching time, combined effect of screen-watching and outdoor time and the emotional problems in preschool children.@*Methods@#A total of 27 200 preschool children aged 3-6 years in 109 kindergartens in 11 cities in Jiangsu, Hubei, Anhui participated in the study. Information on both screen-watching and outdoor time and social-demographic characteristics was collected through the Questionnaire on the healthy Development of Preschool Children. Emotional problems of these children were accessed by using the Strengths and Difficulties Questionnaire (SDQ). Correlation intensity between excessive screen time and emotional problems (suspicious or abnormal) in preschool children, and the combined effects of screen-watching and outdoor time were analyzed by binary logistic regression model.@*Results@#The overall detected rate of emotional symptoms in preschool children was 17.9% (4 868/27 200). Rates showed in preschool children would include: with screen-watching time>1 h/d as 62.4% (16 983/27 200) and with outdoor time<2 h/d as 65.7% (17 873/27 200). After adjusting for confounding factors as gender, age, place of residence, family economic status, BMI, parents’ age and education level, data showed that the screen-watching time was positive correlated with emotional symptoms (OR=1.15, 95%CI: 1.08-1.24) while the outdoor time was positive correlated with emotional symptoms (OR=1.08, 95%CI: 1.01-1.16). Strong correlation between the combination of screen-watching and outdoor time and the existing emotional problems among preschool children was seen.@*Conclusions@#Excessive screen-watching time was prevalent among preschool children. Screen-watching time was positively associated with the existing emotional problems while the combined effect of screen-watching time and outdoor time was stronger.
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China's Sloping Land Conversion Program (SLCP) was designed to restore perennial plant cover on sloping land in western China, in part to protect the Three Gorges Reservoir (TGR). In this study, we examined use of white mulberry (Morus alba L.) in the SLCP to protect water quality and conserve soil. We established nine runoff monitoring plots divided among three categories (vegetable farming, fallow control, and mulberry plantation) on a bank of the Liangtan River situated at the western margin of the TGR. The land had been used previously by farmers for growing vegetables. We found that soil loss and surface water runoff were lowest in the mulberry plots and highest in the vegetable plots. We used inductively coupled plasma atomic emission spectroscopy (ICP-AES) to assess the concentration of selected heavy metal pollution indicators (Zn, Hg, As, Ni, Pb, Cr, Cd, and Cu) in the monitoring plot soils at the beginning of the experiment in May 2009. The heavy metals were assessed again at the end of the experiment in October 2012, and we found that the concentrations of these pollutants had been reduced in all fallow and mulberry plots, and to the greatest extent in the mulberry plots. We found that levels of Hg, Pb, and Cu increased in the vegetable plots. For these reasons, we conclude that riparian mulberry plantations are useful for reducing rapid runoff of storm water, conserving soil, and sequestering heavy metal pollutants in the TGR region.
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Monitoramento Ambiental/métodos , Metais Pesados/análise , Morus , Poluentes do Solo/análise , Morus/química , Morus/metabolismo , Solo/química , Qualidade da ÁguaRESUMO
<p><b>OBJECTIVE</b>To determine the effect of aspirin on cell proliferation, alkaline phosphatase (ALP) activity, cell cycle and apoptosis in murine bone marrow stromal cells, so as to explore an appropriate dose range to improve bone regeneration in periodontal treatment.</p><p><b>METHODS</b>ST2 cells were stimulated with aspirin (concentrations of 1, 10, 100 and 1 000 μmol/L) for 1, 2, 3, 5 and 7 d. Cell proliferation was measured by methyl thiazolyl tetrazolium (MTT) assay. After ST2 cells were treated for 1, 3 and 7 d, ALP activity was measured by ALP kit, cell cycle and apoptosis were measured by flow cytometry (FCM) after treated for 48 h.</p><p><b>RESULTS</b>MTT assays showed that various doses of aspirin have different effects on the cell growth. Briefly, lower concentrations (1, 10 μmol/L) of aspirin promoted the cell growth, the A value of 0, 1 and 10 μmol/L aspirin 7-day-treated cells were 0.313±0.012, 0.413±0.010 and 0.387±0.017 respectively (P <0.01 vs control), and so did the ALP level ([4.3±0.9], [6.0±0.3] and [7.7±0.4] μmol·min(-1)·g(-1), P <0.05 vs control), while higher concentrations, especially 1000 μmol/L of aspirin might inhibit the cell growth with time going, A value and ALP level were 0.267±0.016, (4.3±1.3) μmol·min(-1)·g(-1) respectively (P <0.05 vs control). Cell cycle analysis revealed no changes in comparison to control cells after treatment with 1 or 10 μmol/L aspirin, but it was observed that cell mitosis from S phase to G2/M phase proceeded at higher concentrations of 100 μmol/L aspirin, and the cell cycle in phase G0/G1 arrested at 1000 μmol/L. Parallel apoptosis/necrosis studies showed that the percentage of cells in apoptosis decreased dramatically at all doses of aspirin, the apoptosis rates of ST2 cells responded to 0, 1, 10, 100 and 1000 μmol/L aspirin were (11.50±0.90)%, (5.30±0.10)%, (5.50±0.10)%, (4.90±0.90)% and (7.95±0.25)% respectively (P<0.05 vs control).</p><p><b>CONCLUSIONS</b>This study demonstrated that lower dosage of aspirin can promote ST2 cells growth, osteogenic activity and inhibit its apoptosis. Aspirin maybe used for the bone reconstruction with a proper concentration.</p>
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Animais , Camundongos , Fosfatase Alcalina , Metabolismo , Apoptose , Aspirina , Farmacologia , Regeneração Óssea , Ciclo Celular , Divisão Celular , Linhagem Celular Tumoral , Proliferação de Células , Citometria de Fluxo , Formazans , Células-Tronco Mesenquimais , Biologia Celular , Periodontia , Sais de Tetrazólio , Fatores de TempoRESUMO
<p><b>OBJECTIVE</b>To study the correlation between EEG characteristics of medial prefrontal cortex (mPFC) and drug-seeking behavior of rats with morphine dependent place preference under shuttling condition.</p><p><b>METHODS</b>Forty rats were randomly divided into four groups (n = 10): morphine PL group, NS PL group, morphine IL group and NS IL group. After embeding the electrode in prelimbic (PL) or infralimbic (IL) cortex of each group by brain stereotaxic operation, the model of morphine dependent conditioned place preference (CPP) in rats was established. The differences of EEG wave percentage in mPFC were telemetered and analyzed when rats shuttled before and after the model.</p><p><b>RESULTS</b>After the model, the withdrawal symptoms were evident in morphine PL and IL group, and the activity time and distance in white box were increased obviously. Compared with control group, after the model, the EEG in morphine PL group showed that: when the rats shuttled to white box, 8 wave decreased obviously, P wave increased obviously. When the rats shuttled to black box, brain waves showed opposite changes. The EEG in morphine IL group showed that: when the rats shuttled to white box, a wave increased obviously, P and a wave decreased obviously. When the rats shuttled to black box, the brain wave had no significant differences compared with control group.</p><p><b>CONCLUSION</b>The EEG changes are different in PL and IL cortex of morphine CPP rats under shuttling condition, and the EEG changes are also different when rats shuttling to white or black box. There is possibly different mechanism, when different drug-seeking environmental cues caused EEG changes in different regions of mPFC.</p>
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Animais , Ratos , Condicionamento Psicológico , Sinais (Psicologia) , Comportamento de Procura de Droga , Eletroencefalografia , Dependência de Morfina , Córtex Pré-Frontal , TelemetriaRESUMO
BACKGROUND: Osteoarthritis of the hip is five to ten times more common in white people than in Chinese people. Little is known about the true prevalence of femoroacetabular impingement or its role in the development of osteoarthritis in the Chinese population. A cross-sectional study of both white and Chinese asymptomatic individuals was conducted to compare the prevalences of radiographic features posing a risk for femoroacetabular impingement in the two groups. It was hypothesized that that there would be proportional differences in hip anatomy between the white and Asian populations. METHODS: Pelvic computed tomography scans of 201 subjects (ninety-nine white Belgians and 102 Chinese; 105 men and ninety-six women) without hip pain who were eighteen to forty years of age were assessed. The original axial images were reformatted to three-dimensional pelvic models simulating standardized radiographic views. Ten radiographic parameters predisposing to femoroacetabular impingement were measured: alpha angle, anterior offset ratio, and caput-collum-diaphyseal angle on the femoral side and crossover sign, ischial spine projection, acetabular anteversion angle, center-edge angle, acetabular angle of Sharp, Tönnis angle, and anterior acetabular head index on the acetabular side. RESULTS: The white subjects had a less spherical femoral head than the Chinese subjects (average alpha angle, 56° compared with 50°; p<0.001). The Chinese subjects had less lateral acetabular coverage than the white subjects, with average center-edge angles of 35° and 39° (p<0.001) and acetabular angles of Sharp of 38° and 36° (p<0.001), respectively. A shallower acetabular configuration was predominantly present in Chinese women. CONCLUSIONS: Significant differences in hip anatomy were demonstrated between young asymptomatic Chinese and white subjects. However, the absolute size of the observed differences appears to contrast with the reported low prevalence of femoroacetabular impingement in Chinese individuals compared with the high prevalence in white populations.
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Acetábulo/diagnóstico por imagem , Povo Asiático , Impacto Femoroacetabular/diagnóstico por imagem , Impacto Femoroacetabular/etnologia , Articulação do Quadril/anatomia & histologia , Articulação do Quadril/diagnóstico por imagem , População Branca , Acetábulo/anatomia & histologia , Adolescente , Adulto , Causalidade , Comorbidade , Estudos Transversais , Feminino , Cabeça do Fêmur/anatomia & histologia , Cabeça do Fêmur/diagnóstico por imagem , Colo do Fêmur/anatomia & histologia , Colo do Fêmur/diagnóstico por imagem , Humanos , Masculino , Variações Dependentes do Observador , Osteoartrite/diagnóstico por imagem , Osteoartrite/epidemiologia , Exame Físico , Estudos Prospectivos , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
INTRODUCTION: Previous studies have shown the difficulty in removing calcium hydroxide (Ca[OH]2) paste from the root canals before root filling. METHODS: Mesial and distal canals of 30 mandibular molars were prepared with the WaveOne Primary (25/.08) and Large file (40/.08) (Dentsply Tulsa Dental Specialties, Tulsa, OK), respectively. All canals were then filled with Ca(OH)2. The teeth were divided into the following 3 treatment groups (each with n = 10): (1) instrumentation with needle irrigation, (2) instrumentation with irrigation and passive ultrasonic activation (PUI), and (3) the GentleWave system (Sonendo, Inc, Laguna Hills, CA) without instrumentation. The irrigation time in each group was 7.5 minutes. To further test the efficiency of the GentleWave system, shorter times of 90 seconds were tested using water alone. Reconstructed micro-computed tomographic scans were used to measure the volume of the canals and Ca(OH)2 after instrumentation, initial filling of Ca(OH)2, and after its removal. The percentage of Ca(OH)2 remaining in the canals was calculated. RESULTS: None of the 10 teeth (30 canals) in the conventional irrigation and PUI groups were completely cleaned of Ca(OH)2 in 7.5 minutes. In the apical third of mesial and distal canals, respectively, conventional irrigation removed 47.82% ± 16.36% and 77.68% ± 12.82%, PUI removed 61.66% ± 25.54% and 88.85 ± 12.06%, and the GentleWave system removed significantly more Ca(OH)2 (P < .05) with 100% and 98.78% ± 3.84%. Additional experiments in 10 teeth, using only water as the irrigant, revealed that the GentleWave system removed 99.85% and 99.97% of Ca(OH)2 within 90 seconds without the use of any instruments in the mesial and distal canals, respectively. CONCLUSIONS: The study confirms the difficulty to remove Ca(OH)2 from root canals using conventional methods. The GentleWave system removed the paste within 90 seconds using water irrigation alone.
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Hidróxido de Cálcio/isolamento & purificação , Cavidade Pulpar , Tratamento do Canal Radicular/métodos , Humanos , Dente Molar , Tratamento do Canal Radicular/instrumentação , Irrigação Terapêutica , UltrassomRESUMO
<p><b>OBJECTIVE</b>To analyse the relationship between the electrical activity changes of nucleus accumbens (NAc) shell and the drug-seeking behavior by recording NAc shell electrical activity in conditioned place preference (CPP) rats induced by morphine.</p><p><b>METHODS</b>Forty SD rats were randomly divided into operation-only control group and the morphine-induced CPP group after stereotaxic electrode was buried on rats NAc shell and the latter group was used to establish the morphine CPP model(n = 20). A CPP video system combining with the technique of electrical activity wireless telemetry was used in the study. The NAc electrical activity from each group of rats was recorded by wireless telemetry respectively, which included staying in black or white chamber of video box, shuttling between black-white chambers and between white-black chambers. The electrical activity differences were analyzed by the percentage of each wave.</p><p><b>RESULTS</b>When the morphine-induced rats staying in black chamber, compared with the operation-only control group, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P < 0.05, P < 0.01); when the morphine-induced rats staying in white chamber, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz and 30 - 40 Hz were increased(P < 0.05 , P < 0.01) , that of 10 - 20 Hz was reduced(P < 0.05 , P < 0. 01); when the morphine-induced rats in black- white shuttling status, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P <0.05, P <0.01), that of 10- 30 Hz was reduced( P <0.05); and in the white-black shuttling status, the electrical activity showed that the percentage of 0 - 10 Hz was reduced(P <0.05), that of 10 - 30 Hz was increased(P < 0.05) ; the electrical activity was further compared between staying status and shuttling status in the morphine-induced CPP group. There was no significant difference of electrical activity between the rats in white-black shuttling status and staying in white chamber. However, when rats in black-white shuttling status, compared with staying in black chamber, the electrical activity showed that the percentage of 0 - 10 Hz and 40 - 50 Hz were increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P <0.05).</p><p><b>CONCLUSION</b>The electrical activity changes of NAc shell in morphine-induced CPP rats were different from those of the operation-only control group, and these changes might be associated to the rat's drug-seeking behavior.</p>
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Animais , Ratos , Condicionamento Psicológico , Comportamento de Procura de Droga , Morfina , Farmacologia , Núcleo Accumbens , Fisiologia , Ratos Sprague-Dawley , TelemetriaRESUMO
The purpose of the present study is to explore the relationship of spatial learning ability and specific electrical activities of neural oscillations in the rat. The fast and general avoidance response groups were selected on the basis of the animals' responses to the electric shock in Y type maze, and their local field potentials (LFPs) of hippocampal CA3 area were recorded by wireless telemetry before and after shock avoidance training, respectively. The components of neural oscillations related to spatial identifying and learning ability were analyzed. The results showed that, compared with the general avoidance response group, the fast avoidance response group did not show any differences of LFPs in hippocampal CA3 area before electric shock avoidance trial, but showed significantly increased percentages of 0-10 Hz and 30-40 Hz rhythm in right hippocampal CA3 area after the shock avoidance training (P < 0.01 or P < 0.05). Fast Fourier transform showed that percentage increase of 0-10 Hz band occurred mainly in θ (3-7 Hz) frequency, and 30-40 Hz frequency change was equivalent to the γ1 band. Furthermore, compared with those before training, only the percentages of β, β2 (20-30 Hz) and γ1 rhythm increased (P < 0.01 or P < 0.05) in fast avoidance response rats after training, while the θ rhythm percentage remained unchanged. In contrast, θ rhythm percentage and the large amplitude (intensity: +2.5 - -2.5 db) θ waves in right CA3 area of general avoidance response rats were significantly reduced after training (P < 0.01). These results suggest that the increased percentages of β2 and γ1 rhythm and high-level (unchanged) percentage of θ rhythm in the right hippocampus CA3 area might be related to strong spatial cognition ability of fast avoidance response rats.
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Animais , Ratos , Aprendizagem da Esquiva , Ritmo beta , Região CA3 Hipocampal , Fisiologia , Eletrochoque , Ritmo Gama , Aprendizagem Espacial , Ritmo TetaRESUMO
<p><b>OBJECTIVE</b>To analyze the electrical activity property changes in nucleus accumbens (NAc) of heroin-induced conditioned place preference (CPP) rats during different stages of heroin dependence and to explore NAc's roles in the formation of drug dependence.</p><p><b>METHODS</b>Recording electrodes were bilaterally embedded into the NAcs of rats with the aid of stereotaxic apparatus, followed by establishment of heroin-dependent rat model. The NAc electrical activity during 3 different stages of heroin dependence, including heroin pre-exposure, immediate post-exposure and heroin withdrawal, were respectively recorded using EEG wireless telemetry techniques. The frequency distribution (ranging from 0.5 to 30 Hz) and the amplitude of NAc electrical activity were analyzed and measured.</p><p><b>RESULTS</b>Heroin-dependent rat models were successfully established and their withdrawal symptoms were evident. All rats showed a conditioned place preference (CPP) for the white box after 5-10 days of heroin-exposure, and displayed a maximum withdrawal symptoms on 2d after heroin- withdrawal. During all statges of heroin-dependence, the NAc electrical activity contained the highest proportion of delta rhythm and the lowest proportion of alpha2 rhythm. The discharge frequence band was similar across different stages. There was a significantly increased ratio of low-frequency discharges (delta rhythm) and decreased ratio of high-frequency discharges (beta rhythm) in NAc of rats during the immediate post- heroin exposure stage when compared with that during pre-exposure and heroin withdrawal stages. During the withdrawal stage, the ratio of at rhythm was significantly lower than during pre- and post-heroin exposure stages (P < 0.01). Further, the mean discharge amplitude in NAcs during immediate post-exposure and withdrawal stages was significantly increased relative to pre-exposure stage. However, the mean discharge amplitude during heroin withdrawal stage was significantly lower than during immediate post-exposure stage.</p><p><b>CONCLUSION</b>The electrical activity properties in rat NAcs showed a significant change during different stages of heroin-dependence, which suggested that neuronal activities in NAcs might contribute to the modulation of drug-dependence.</p>
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Animais , Masculino , Ratos , Condicionamento Operante , Heroína , Farmacologia , Dependência de Heroína , Núcleo Accumbens , Ratos Sprague-Dawley , TelemetriaRESUMO
The purpose of the present study is to analyze the relationship between the telemetry electroencephalogram (EEG) changes of the prelimbic (PL) cortex and the drug-seeking behavior of morphine-induced conditioned place preference (CPP) rats by using the wavelet packet extraction and entropy measurement. The recording electrode was stereotactically implanted into the PL cortex of rats. The animals were then divided randomly into operation-only control and morphine-induced CPP groups, respectively. A CPP video system in combination with an EEG wireless telemetry device was used for recording EEG of PL cortex when the rats shuttled between black-white or white-black chambers. The telemetry recorded EEGs were analyzed by wavelet packet extraction, Welch power spectrum estimate, normalized amplitude and Shannon entropy algorithm. The results showed that, compared with operation-only control group, the left PL cortex's EEG of morphine-induced CPP group during black-white chamber shuttling exhibited the following changes: (1) the amplitude of average EEG for each frequency bands extracted by wavelet packet was reduced; (2) the Welch power intensity was increased significantly in 10-50 Hz EEG band (P < 0.01 or P < 0.05); (3) Shannon entropy was increased in β, γ₁, and γ₂waves of the EEG (P < 0.01 or P < 0.05); and (4) the average information entropy was reduced (P < 0.01). The results suggest that above mentioned EEG changes in morphine-induced CPP group rat may be related to animals' drug-seeking motivation and behavior launching.
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Animais , Ratos , Condicionamento Psicológico , Comportamento de Procura de Droga , Eletroencefalografia , Entropia , Morfina , Farmacologia , Córtex Pré-Frontal , Telemetria , Análise de OndaletasRESUMO
Si Shen Wan (SSW) is used to effectively treat ulcerative colitis (UC) as a formula of traditional Chinese medicine. To explore the mechanism of SSW-inhibited apoptosis of colonic epithelial cell, the study observed mRNA expression of apoptosis-related molecules in p38 MAPK signal pathway in colonic mucosa in colitis mice treated with SSW. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice; meanwhile, the mice were administrated daily either SSW (5 g/kg) or p38 MAPK inhibitor (2 mg/kg) or vehicle (physiological saline) for 10 days. While microscopical evaluation was observed, apoptosis rate of colonic epithelial cell and mRNA expression of apoptosis-related molecules were tested. Compared with colitis mice without treatment, SSW alleviated colonic mucosal injuries and decreased apoptosis rate of colonic epithelial cell, while the mRNA expressions of p38 MAPK, p53, caspase-3, c-jun, c-fos, Bax, and TNF- α were decreased in the colonic mucosa in colitis mice treated with SSW, and Bcl-2 mRNA and the ratio of Bcl-2/Bax were increased. The present study demonstrated that SSW inhibited mRNA expression of apoptosis-related molecules in p38 MAPK signal pathway to downregulate colonic epithelial cells apoptosis in colonic mucosa in mice with colitis.
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ETHNOPHARMACOLOGICAL RELEVANCE: Si Shen Wan is a traditional Chinese herbal medicine formula for the treatment of diseases with diarrhea, such as ulcerative colitis, allergic colitis and chronic colitis. To investigate the protective and healing effects of Si Shen Wan in the experimental colitis induced by trinitrobenzene sulphonic acid, and to furture explore its mechanism of action. MATERIALS AND METHODS: Rats with colitis treated with Si Shen Wan for 10 days. Colon wet weight, colon organ coefficient, colonic damage score and pathological change after trinitrobenzene sulphonic acid challenge were determined. The levels of MPO, MDA, GSH-PX, SOD and the expression of IL-4 and IL-10 mRNA in the colon were also measured. RESULTS: After treatment, colon wet weight, colon organ coefficient and colonic damage score were lower than that in the control group (p<0.05). MDA and MPO concentrations in the inflamed colonic tissues were decreased remarkably in the treated groups compared with that in the control group (p<0.05). But SOD level, IL-4 and IL-10 mRNA expression in the inflamed colonic tissues were obviously increased. CONCLUSIONS: It is a potential path that protective effect of Si Shen Wan on impaired colonic mucosa rats with experimental colitis was accomplished by down-regulating the level of MDA and MPO, and up-regulating the level of SOD and the IL-4 and IL-10 mRNA expression in the colon mucosa.