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基于改进Alpha Shape算法的点云数据岛屿边界提取
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作者 宋晓辉 熊祖雄 +2 位作者 张炎 吕富强 韦建林 《海洋测绘》 CSCD 北大核心 2024年第1期58-62,共5页
针对机载LiDAR点云的岛屿岸线提取过程复杂、附属岛屿岸线难以提取等问题,提出一种基于改进Alpha Shape算法的点云数据岛屿边界提取方法。首先利用布料模拟滤波算法剔除非岛屿点云数据,通过欧式聚类进行不同岛屿的提取,再将岛屿点云数... 针对机载LiDAR点云的岛屿岸线提取过程复杂、附属岛屿岸线难以提取等问题,提出一种基于改进Alpha Shape算法的点云数据岛屿边界提取方法。首先利用布料模拟滤波算法剔除非岛屿点云数据,通过欧式聚类进行不同岛屿的提取,再将岛屿点云数据投影至二维平面,并根据岛屿点云构建格网。在此基础上使用自适应Alpha Shape算法,对提取出的岛屿点云进行边界提取,即可得到岛屿的岸线轮廓。选取新西兰的玛提尤/萨姆斯岛作为研究区域,并将本文算法与Alpha Shape算法进行对比,结果表明:本文算法提取岛屿边界点云的精准度为97.78%,可以准确地提取岛屿岸线,为海岛规划提供参考。 展开更多
关键词 摄影测量 机载LiDAR点云 边界提取 欧式聚类 自适应alpha Shape
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Numerical study of alpha particle loss with toroidal field ripple based on CFETR steady-state scenario
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作者 李钮琦 徐颖峰 +1 位作者 钟方川 张德兵 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期503-510,共8页
Effects of plasma equilibrium parameters on the alpha particle loss with the toroidal field ripple based on the CFETR steady-state scenario have been numerically investigated by the orbit-following code GYCAVA. It is ... Effects of plasma equilibrium parameters on the alpha particle loss with the toroidal field ripple based on the CFETR steady-state scenario have been numerically investigated by the orbit-following code GYCAVA. It is found that alpha particle losses decrease and loss regions become narrower with the plasma current increasing or with the magnetic field decreasing. It is because the ripple stochastic transport and the ripple well loss of alpha particle are reduced with the safety factor decreasing. Decrease of the plasma density and temperature can reduce alpha particle losses due to enhancement of the slowing-down effect. The direction of the toroidal magnetic field can significantly affect heat loads induced by lost alpha particle. The vertical asymmetry of heat loads induced by the clockwise and counter-clockwise toroidal magnetic fields are due to the fact that the ripple distribution is asymmetric about the mid-plane, which can be explained by the typical orbits of alpha particle. The maximal heat load of alpha particle for the clockwise toroidal magnetic field is much smaller than that for the counter-clockwise one. 展开更多
关键词 alpha particle loss RIPPLE orbit-following TOKAMAK
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Alpha7 nicotinic receptors as potential theranostic targets for experimental stroke
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作者 Maider Garbizu Laura Aguado Abraham Martín 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第5期939-940,共2页
Inflammatory reflex and cholinergic anti-inflammatory pathway:Innate immune system triggers a local inflammatory response following an injury or a pathogen invasion.Likewise,this inflammatory response is limited by ra... Inflammatory reflex and cholinergic anti-inflammatory pathway:Innate immune system triggers a local inflammatory response following an injury or a pathogen invasion.Likewise,this inflammatory response is limited by rapid,localized,and adaptive anti-inflammatory responses which are crucial for maintaining homeostasis.Hence,the loss of these responses converts a limited and protective inflammatory response into an excessive and harmful response.Anti-inflammatory responses are integrated into the central nervous system,since the central nervous system accumulates information about harmful events,activates defenses,and builds memory for survival.At the same time,it has been demonstrated that hypothalamic neuronal signaling can be altered by inflammation in peripheral tissues.Additionally,immune cells release neuropeptides and neurotransmitters such as acetylcholine(ACh),the main neurotransmitter of the parasympathetic autonomic nervous system,evidencing the communication between the immune and nervous systems(Tracey,2002). 展开更多
关键词 protective INVASION alpha
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Hydrographic Characteristics and Oceanic Heat Flux in the Upper Arctic Ocean over the Alpha Ridge Observed by the DTOP Platform in 2018 and 2021
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作者 WANG Yongjun LI Tao 《Journal of Ocean University of China》 CAS CSCD 2024年第2期304-316,共13页
In 2018 and 2021,the Drift-Towing Ocean Profilers(DTOP)provided extensive temperature and salinity data on the upper 120m ocean through their drifts over the Alpha Ridge north of the Canada Basin.The thickness and tem... In 2018 and 2021,the Drift-Towing Ocean Profilers(DTOP)provided extensive temperature and salinity data on the upper 120m ocean through their drifts over the Alpha Ridge north of the Canada Basin.The thickness and temperature maximum of Alaska Coastal Water(ACW)ranged from 20m to 40m and-1.5℃to-0.8℃,respectively,and the salinity generally maintained from 30.2 to 32.5.Comparison with World Ocean Atlas 2018’s climatology manifested a 40m-thick and warm ACW roughly ex-ceeding the temperature maximum by 0.4–0.5℃in June–August 2021.This anomalously warm ACW was highly related to the ex-pansion of the Beaufort Gyre in the negative Arctic Oscillation phase.During summer,the under-ice oceanic heat flux F_(w)^(OHF)was elevated,with a maximum value of above 25Wm^(-2).F_(w)^(OHF)was typically low in the freezing season,with an average value of 1.2Wm^(-2).The estimates of upward heat flux contributed by ACW to the sea ice bottom F_(w)^(OHF)were in the range of 3–4Wm^(-2)in June–August 2021,when ACW contained a heat content of more than 80MJm^(-2).The heat loss over this period was driven by a weak stratification upon the ACW layer associated with a surface mixed layer(SML)approaching the ACW core.After autumn,F_(w)^(OHF)was reduced(<2 Wm^(-2))except during rare events when it elevated F_(w)^(OHF)slightly.In addition,the intensive and widespread Ekman suction,which created a violent upwelling north of the Canada Basin,was largely responsible for the substantial cooling and thinning of the ACW layer in the summer of 2021. 展开更多
关键词 Arctic Ocean oceanic heat flux Alaska Coastal Water alpha Ridge
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Gross Alpha and Beta Activities and Related Lifetime Risks Assessment Due to Ingestion of Drinking Water from Different Sources in the District of Abidjan, Cote d’Ivoire
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作者 Ponaho Claude Kezo Issa Konate Dabo Salif Ignace Agba 《World Journal of Nuclear Science and Technology》 CAS 2024年第1期86-96,共11页
Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the ... Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the objective of this study was to assess the risk of cancer due to the ingestion of alpha and beta emitting radionuclides in the different types of water consumed in the region. A total of 63 water samples with 43 tap water samples, 5 bottled mineral water and 15 sachet water samples was collected and taken to GAEC laboratory for analysis. The low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) was used to determine alpha and beta activity concentrations. Activity concentrations of both gross alpha and gross beta obtained in water sample were respectively lower than the WHO recommended limits of 0.1 Bq/l and 1 Bq/l. Also, the annual effective dose and total equivalent effective dose found in mineral bottled water samples were higher than in other types of water. The assessment of radiological lifetime risk has shown values of cancer risk due to ingestion alpha and beta emitters lower than recommended limit. These results indicate that there is no health hazard associated to consumption of water in the District of Abidjan. 展开更多
关键词 Gross alpha and Beta Activities Drinking Water Effective Dose Radiological Lifetime Risks
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改进Alpha Shapes和快速凸壳算法的SVM故障诊断
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作者 宋仁旺 杨磊 +2 位作者 余百千 石慧 董增寿 《机床与液压》 北大核心 2023年第13期212-217,共6页
现有的基于凸壳的支持向量机(SVM)算法处理机械装备产生的大规模原始数据时间太长。针对这一问题,通过结合轮廓提取算法(Alpha Shapes)和快速凸壳算法,提出一种结合改进快速凸壳算法的SVM用于故障诊断研究。该融合算法利用改进简化的Alp... 现有的基于凸壳的支持向量机(SVM)算法处理机械装备产生的大规模原始数据时间太长。针对这一问题,通过结合轮廓提取算法(Alpha Shapes)和快速凸壳算法,提出一种结合改进快速凸壳算法的SVM用于故障诊断研究。该融合算法利用改进简化的Alpha Shapes算法提取点集的边界数据点,作为改进的快速凸壳算法的对象,减少凸壳算法递归的工作量。实验结果表明:该算法平均只提取了数据集0.26%的数据点,且计算的时间也相应降低。最后实验同样表明该算法的性能优于单一的SVM算法。 展开更多
关键词 大规模数据 支持向量机 凸壳超平面 alpha Shapes 故障诊断
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Alpha稳定分布噪声下基于轻量级网络的自动调制识别技术
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作者 李汀 邢怀志 张进标 《信号处理》 CSCD 北大核心 2023年第5期899-909,共11页
自动调制识别在无线通信领域发挥了巨大作用。多数研究中假设的加性高斯白噪声信道已不再满足实际信道环境的准确描述。实际中,由于闪电、雷暴、多用户干扰、设备故障等原因,信道环境中广泛存在Alpha稳定分布噪声。因此对其开展研究更... 自动调制识别在无线通信领域发挥了巨大作用。多数研究中假设的加性高斯白噪声信道已不再满足实际信道环境的准确描述。实际中,由于闪电、雷暴、多用户干扰、设备故障等原因,信道环境中广泛存在Alpha稳定分布噪声。因此对其开展研究更符合实际且具有挑战性。该文针对Alpha稳定分布噪声提出了一种预处理联合轻量级网络的调制识别方法。首先,通过对数域映射及阈值限制对接收信号进行预处理,抑制由Alpha稳定分布噪声带来的尖锐脉冲将信号幅度控制到合理范围;然后,提出一种基于Ghost模块的轻量级网络来完成信号的调制识别分类任务。实验结果表明,与现有的CLDNN(Convolutional Long Short-term Deep Neural Network)、CNN(Convolutional Neural Network)、ResNe(t Residual Network)相比,本文所提方法具有较高的识别准确率及较低的计算复杂度。 展开更多
关键词 自动调制识别 alpha稳定分布噪声 深度学习
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Alpha稳定分布噪声下基于特征值之差频谱感知算法
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作者 陈增茂 汪楷淋 +2 位作者 孙志国 孙溶辰 阿尔斯楞 《系统工程与电子技术》 EI CSCD 北大核心 2023年第9期2949-2955,共7页
针对基于特征值的谱感知算法在脉冲噪声的环境下感知性能不佳的问题,分析矩阵全部的特征值,引入矩阵特征值的几何均值,提出了基于分数低阶协方差矩阵的最大特征值与特征值几何均值之差(difference between maximum eigenvalue and geome... 针对基于特征值的谱感知算法在脉冲噪声的环境下感知性能不佳的问题,分析矩阵全部的特征值,引入矩阵特征值的几何均值,提出了基于分数低阶协方差矩阵的最大特征值与特征值几何均值之差(difference between maximum eigenvalue and geometric mean of eigenvalue,DMGM)的频谱感知算法。选择了Alpha稳定分布噪声模拟脉冲噪声环境,理论分析与仿真实验结果表明,在不增加算法复杂度的前提下,DMGM算法与其他算法相比,更适用于脉冲噪声环境,在低信噪比条件下具有更好的感知性能。 展开更多
关键词 频谱感知 alpha稳定分布 分数低阶矩 采样协方差 几何均值
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模型与数据双驱动的失眠脑电alpha节律研究
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作者 李强 潘敏 成波 《西北大学学报(自然科学版)》 CAS CSCD 北大核心 2023年第3期359-366,共8页
失眠是一种典型的睡眠障碍,以入睡困难、睡眠深度或频度过短、早醒及睡眠时间不足等为主要特征。临床上一些失眠患者在快速眼动(REM)睡眠期会出现明显的脑电alpha节律活动增强现象,但发生这一现象的内在机制尚不清楚。基于此,从计算神... 失眠是一种典型的睡眠障碍,以入睡困难、睡眠深度或频度过短、早醒及睡眠时间不足等为主要特征。临床上一些失眠患者在快速眼动(REM)睡眠期会出现明显的脑电alpha节律活动增强现象,但发生这一现象的内在机制尚不清楚。基于此,从计算神经科学的角度出发,结合Liley神经计算模型与临床失眠脑电数据,探索失眠患者在REM期典型放电节律的发生机制。首先,设计一种基于马尔可夫蒙特卡洛的Liley模型关键参数的自动选择与估计方法;其次,结合失眠患者脑电数据,确定影响alpha节律发放的模型关键参数,并据此给出失眠患者REM期脑电alpha节律活动增强的机制假设:抑制性突触活动强度的降低会诱导alpha节律活动的增强。所获结果对于改善失眠患者的睡眠质量并控制病情发展具有一定的指导作用和临床价值。 展开更多
关键词 失眠 脑电alpha节律 Liley模型 关键参数
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Counting of alpha particle tracks on imaging plate based on a convolutional neural network 被引量:1
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作者 Feng-Di Qin Han-Yu Luo +5 位作者 Zheng-Zhong He Ke-Jun Lu Chuan-Gao Wang Meng-Meng Wu Zhong-Kai Fan Jian Shan 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第3期52-63,共12页
Imaging plates are widely used to detect alpha particles to track information,and the number of alpha particle tracks is affected by the overlapping and fading effects of the track information.In this study,an experim... Imaging plates are widely used to detect alpha particles to track information,and the number of alpha particle tracks is affected by the overlapping and fading effects of the track information.In this study,an experiment and a simulation were used to calibrate the efficiency parameter of an imaging plate,which was used to calculate the grayscale.Images were created by using grayscale,which trained the convolutional neural network to count the alpha tracks.The results demonstrated that the trained convolutional neural network can evaluate the alpha track counts based on the source and background images with a wider linear range,which was unaffected by the overlapping effect.The alpha track counts were unaffected by the fading effect within 60 min,where the calibrated formula for the fading effect was analyzed for 132.7 min.The detection efficiency of the trained convolutional neural network for inhomogeneous ^(241)Am sources(2π emission)was 0.6050±0.0399,whereas the efficiency curve of the photo-stimulated luminescence method was lower than that of the trained convolutional neural network. 展开更多
关键词 Imaging plate Convolutional neural network alpha tracks counting
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A generalized alpha function of Peng-Robison equation of state for non-polar,weakly polar and polar compounds
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作者 Wenying Zhao Yuxiang Ge +2 位作者 Xuxue Zhang Xiaoyan Sun Shuguang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期234-243,共10页
A novel alpha function for Peng-Robinson equation of state was proposed and generalized with acentric factor and dipole moment for predicting thermodynamic properties of non-polar,weakly polar,and polar compounds.The ... A novel alpha function for Peng-Robinson equation of state was proposed and generalized with acentric factor and dipole moment for predicting thermodynamic properties of non-polar,weakly polar,and polar compounds.The parameters of new alpha function were fitted with vapor pressures of 70 compounds.Six different methods were investigated for the correlation of parameters of new alpha function and Heyen alpha function.The generalized new alpha function passed the consistency test.The results indicated that the predictive accuracy of generalized new alpha function and generalized Heyen alpha function was improved for the estimation of vapor pressure of 11 kinds of compounds,with the average relative deviations(ARDs)being 2.60%and 2.76%.The ARDs of the two generalized alpha functions were 2.04%and 2.09%for the enthalpy of vaporization.However,the generalized new alpha function and the other alpha functions had great deviations for the prediction of liquid volumes and isobaric heat capacities.The alpha function that was generalized with acentric factor and reduced dipole moment was more accurate than that was generalized with acentric factor,especially for the prediction of vapor pressure and enthalpy of vaporization of polar compounds. 展开更多
关键词 PR EoS alpha function Acentric factor Reduced dipole moment
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Alpha2-adrenergic receptor activation reinstates motor deficits in rats recovering from cortical injury
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作者 Gabriela García-Díaz Laura ERamos-Languren +6 位作者 Carmen Parra-Cid Joel Lomelí Sergio Montes Camilo Ríos Antonio Bueno-Nava Ignacio Valencia-Hernández Rigoberto González-Piña 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第4期875-880,共6页
Norepinephrine plays an important role in motor functional recovery after a brain injury caused by ferrous chloride.Inhibition of norepinephrine release by clonidine is correlated with motor deficits after motor corte... Norepinephrine plays an important role in motor functional recovery after a brain injury caused by ferrous chloride.Inhibition of norepinephrine release by clonidine is correlated with motor deficits after motor cortex injury.The aim of this study was to analyze the role ofα-adrenergic receptors in the restoration of motor deficits in recovering rats after brain damage.The rats were randomly assigned to the sham and injury groups and then treated with the following pharmacological agents at 3 hours before and 8 hours,3 days,and 20 days after ferrous chloride-induced cortical injury:saline,clonidine,efaroxan(a selective antagonist ofα-adrenergic receptors)and clonidine+efaroxan.The sensorimotor score,the immunohistochemical staining forα-adrenergic receptors,and norepinephrine levels were evaluated.Eight hours post-injury,the sensorimotor score and norepinephrine levels in the locus coeruleus of the injured rats decreased,and these effects were maintained 3 days post-injury.However,20 days later,clonidine administration diminished norepinephrine levels in the pons compared with the sham group.This effect was accompanied by sensorimotor deficits.These effects were blocked by efaroxan.In conclusion,an increase inα-adrenergic receptor levels was observed after injury.Clonidine restores motor deficits in rats recovering from cortical injury,an effect that was prevented by efaroxan.The underlying mechanisms involve the stimulation of hypersensitiveα-adrenergic receptors and inhibition of norepinephrine activity in the locus coeruleus.The results of this study suggest thatαreceptor agonists might restore deficits or impede rehabilitation in patients with brain injury,and therefore pharmacological therapies need to be prescribed cautiously to these patients. 展开更多
关键词 alpha2-adrenoceptors ambulatory behavior CLONIDINE cortical injury EFAROXAN functional recovery immunohistochemistry motor deficit norepinephrine sensorimotor score
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A Novel Modified Alpha Power Transformed Weibull Distribution and Its Engineering Applications
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作者 Refah Alotaibi Hassan Okasha +1 位作者 Mazen Nassar Ahmed Elshahhat 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2065-2089,共25页
This paper suggests a new modified version of the traditional Weibull distribution by adding a new shape parameter utilising the modified alpha power transformed technique.We refer to the new model as modified alpha p... This paper suggests a new modified version of the traditional Weibull distribution by adding a new shape parameter utilising the modified alpha power transformed technique.We refer to the new model as modified alpha power transformed Weibull distribution.The attractiveness and significance of the new distribution lie in its power to model monotone and non-monotone failure rate functions,which are quite familiar in environmental investigations.Its hazard rate function can be decreasing,increasing,bathtub and upside-down then bathtub shaped.Diverse structural properties of the proposed model are acquired including quantile function,moments,entropies,order statistics,residual life and reversed failure rate function.The parameters of the distribution were estimated using the maximum likelihood function.The maximum likelihood method is employed to estimate the model parameters and the approximate confidence intervals are also computed.Via a simulation study,the performance of the point and interval estimates are compared using different criteria.Employing real lifetime data sets,we verify that the offered model furnishes a better fit than some other lifetime models including Weibull,gamma and alpha powerWeibull models. 展开更多
关键词 Weibull distribution modified alpha power transformationmethod maximum likelihood ENTROPY order statistics
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A higher prediction accuracy–based alpha–beta filter algorithm using the feedforward artificial neural network
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作者 Junaid Khan Eunkyu Lee Kyungsup Kim 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第4期1124-1139,共16页
The alpha–beta filter algorithm has been widely researched for various applications,for example,navigation and target tracking systems.To improve the dynamic performance of the alpha–beta filter algorithm,a new pred... The alpha–beta filter algorithm has been widely researched for various applications,for example,navigation and target tracking systems.To improve the dynamic performance of the alpha–beta filter algorithm,a new prediction learning model is proposed in this study.The proposed model has two main components:(1)the alpha–beta filter algorithm is the main prediction module,and(2)the learning module is a feedforward artificial neural network(FF‐ANN).Furthermore,the model uses two inputs,temperature sensor and humidity sensor data,and a prediction algorithm is used to predict actual sensor readings from noisy sensor readings.Using the novel proposed technique,prediction accuracy is significantly improved while adding the feed‐forward backpropagation neural network,and also reduces the root mean square error(RMSE)and mean absolute error(MAE).We carried out different experiments with different experimental setups.The proposed model performance was evaluated with the traditional alpha–beta filter algorithm and other algorithms such as the Kalman filter.A higher prediction accuracy was achieved,and the MAE and RMSE were 35.1%–38.2%respectively.The final proposed model results show increased performance when compared to traditional methods. 展开更多
关键词 alpha beta filter artificial neural network navigation prediction accuracy target tracking problems
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Role of lymphotoxin alpha as a new molecular biomarker in revolutionizing tear diagnostic testing for dry eye disease
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作者 Chao-Ran Li 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第11期1883-1889,共7页
Dry eye disease(DED),primarily classified as multifactorial ocular surface disorder,afflicts tens of millions of individuals worldwide,adversely impacting their quality of life.Extensive research has been conducted on... Dry eye disease(DED),primarily classified as multifactorial ocular surface disorder,afflicts tens of millions of individuals worldwide,adversely impacting their quality of life.Extensive research has been conducted on tear film analysis over the past decades,offering a range of tests to evaluate its volume,health,and integrity.Yet,early diagnosis and effective treatment for DED continue to pose significant challenges in clinical settings.Nevertheless,by recognizing key phenomena in DED such as ocular surface inflammation,hyperosmolarity,and tear film instability,this article provides a comprehensive overview of both traditional and recently developed methods for diagnosing and monitoring DED.The information serves as a valuable resource not only for clinical diagnosis but also for further research into DED. 展开更多
关键词 dry eye disease tear film BIOMARKER matrix metalloproteinase 9 lymphotoxin alpha
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Functional role of frontal electroencephalogram alpha asymmetry in the resting state in patients with depression:A review
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作者 Yu-Hong Xie Ye-Min Zhang +2 位作者 Fan-Fan Fan Xi-Yan Song Lei Liu 《World Journal of Clinical Cases》 SCIE 2023年第9期1903-1917,共15页
Depression is a psychological disorder that affects the general public worldwide.It is particularly important to make an objective and accurate diagnosis of depression,and the measurement methods of brain activity hav... Depression is a psychological disorder that affects the general public worldwide.It is particularly important to make an objective and accurate diagnosis of depression,and the measurement methods of brain activity have gradually received increasing attention.Resting electroencephalogram(EEG)alpha asymmetry in patients with depression shows changes in activation of the alpha frequency band of the left and right frontal cortices.In this paper,we review the findings of the relationship between frontal EEG alpha asymmetry in the resting state and depression.Based on worldwide studies,we found the following:(1)Compared with individuals without depression,those with depression showed greater right frontal EEG alpha asymmetry in the resting state.However,the pattern of frontal EEG alpha asymmetry in the resting state in depressive individuals seemed to disappear with age;(2)Compared with individuals without maternal depression,those with maternal depression showed greater right frontal EEG alpha asymmetry in the resting state,which indicated that genetic or experience-based influences have an impact on frontal EEG alpha asymmetry at rest;and(3)Frontal EEG alpha asymmetry in the resting state was stable,and little or no change occurred after antidepressant treatment.Finally,we concluded that the contrasting results may be due to differences in methodology,clinical characteristics,and participant characteristics. 展开更多
关键词 DEPRESSION Frontal electroencephalogram alpha asymmetry Frontal asymmetry Resting state Neurological indicator
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Joint Detection of Serum Vitamin D,Body Mass Index,and Tumor Necrosis Factor Alpha for the Diagnosis of Crohn’s Disease
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作者 Ying ZHENG Jing-hong LI +7 位作者 Shan-ying LIAO Yi-ming FU Yan-jun ZHANG Jun-long LIN Xin-bin CHEN Wei-hong SHA Shi-xue DAI Wen-jun MA 《Current Medical Science》 SCIE CAS 2023年第3期496-504,共9页
Objective Vitamin D(VD)deficiency was reported to contribute to the progression of Crohn’s disease(CD)and affect the prognosis of CD patients.This study investigated the role of serum VD,body mass index(BMI),and tumo... Objective Vitamin D(VD)deficiency was reported to contribute to the progression of Crohn’s disease(CD)and affect the prognosis of CD patients.This study investigated the role of serum VD,body mass index(BMI),and tumor necrosis factor alpha(TNF-α)in the diagnosis of Crohn’s disease.Methods CD patients(n=76)and healthy subjects(n=76)were enrolled between May 2019 and December 2020.The serum 25-hydroxyvitamin D[25(OH)D]levels,BMI,and TNF-αlevels,together with other biochemical parameters,were assessed before treatment.The diagnostic efficacy of the single and joint detection of serum 25(OH)D,BMI,and TNF-αwas determined using receiver operating characteristic(ROC)curves.Results The levels of 25(OH)D,BMI,and nutritional indicators,including hemoglobin,total protein,albumin,and high-density lipoprotein cholesterol,were much lower,and the TNF-αlevels were much higher in the CD patients than in the healthy subjects(P<0.05 for all).The areas under the ROC curve for the single detection of 25(OH)D,BMI,and TNF-αwere 0.887,0.896,and 0.838,respectively,with the optimal cutoff values being 20.64 ng/mL,19.77 kg/m^(2),and 6.85 fmol/mL,respectively.The diagnostic efficacy of the joint detection of 25(OH)D,BMI,and TNF-αwas the highest,with an area under the ROC curve of 0.988(95%CI:0.968–1.000).Conclusion The joint detection of 25(OH)D,TNF-α,and BMI showed high sensitivity,specificity,and accuracy in CD diagnosis;thus,it would be effective for the diagnosis of CD in clinical practice. 展开更多
关键词 Crohn’s disease vitamin D body mass index tumor necrosis factor alpha
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F-box only protein 2 exacerbates non-alcoholic fatty liver disease by targeting the hydroxyl CoA dehydrogenase alpha subunit
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作者 Zhi Liu Ning-Yuan Chen +2 位作者 Zhao Zhang Sai Zhou San-Yuan Hu 《World Journal of Gastroenterology》 SCIE CAS 2023年第28期4433-4450,共18页
BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive... BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive and therapeutic measures.AIM To explore the molecular mechanism of NAFLD.METHODS Whole genome sequencing(WGS)analysis was performed on liver tissues from patients with NAFLD(n=6)and patients with normal metabolic conditions(n=6)to identify the target genes.A NAFLD C57BL6/J mouse model induced by 16 wk of high-fat diet feeding and a hepatocyte-specific F-box only protein 2(FBXO2)overexpression mouse model were used for in vivo studies.Plasmid transfection,co-immunoprecipitation-based mass spectrometry assays,and ubiquitination in HepG2 cells and HEK293T cells were used for in vitro studies.RESULTS A total of 30982 genes were detected in WGS analysis,with 649 up-regulated and 178 down-regulated.Expression of FBXO2,an E3 ligase,was upregulated in the liver tissues of patients with NAFLD.Hepatocyte-specific FBXO2 overexpression facilitated NAFLD-associated phenotypes in mice.Overexpression of FBXO2 aggravated odium oleate(OA)-induced lipid accumulation in HepG2 cells,resulting in an abnormal expression of genes related to lipid metabolism,such as fatty acid synthase,peroxisome proliferator-activated receptor alpha,and so on.In contrast,knocking down FBXO2 in HepG2 cells significantly alleviated the OA-induced lipid accumulation and aberrant expression of lipid metabolism genes.The hydroxyl CoA dehydrogenase alpha subunit(HADHA),a protein involved in oxidative stress,was a target of FBXO2-mediated ubiquitination.FBXO2 directly bound to HADHA and facilitated its proteasomal degradation in HepG2 and HEK293T cells.Supplementation with HADHA alleviated lipid accumulation caused by FBXO2 overexpression in HepG2 cells.CONCLUSION FBXO2 exacerbates lipid accumulation by targeting HADHA and is a potential therapeutic target for NAFLD。 展开更多
关键词 F-box only protein 2 Nonalcoholic fatty liver disease The hydroxyl CoA dehydrogenase alpha subunit Liver steatosis Ubiquitination Lipid accumulation
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利用AlphaMissense准确预测蛋白质组的错义突变
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作者 赵林(编译) 《广东药科大学学报》 CAS 2023年第5期14-14,共1页
在人类基因组中观察到的绝大多数错义突变具有未知的临床意义。研究人员开发了AlphaMissense,这是一种基于AlphaFold的新AI模型,它在人类和灵长类物种变异群体频率数据库上进行了微调,用于预测错义突变的致病性。通过结合结构背景和进... 在人类基因组中观察到的绝大多数错义突变具有未知的临床意义。研究人员开发了AlphaMissense,这是一种基于AlphaFold的新AI模型,它在人类和灵长类物种变异群体频率数据库上进行了微调,用于预测错义突变的致病性。通过结合结构背景和进化保守性,AlphaMissense在广泛的遗传和实验性基准测试中实现了最先进的预测,而且完全没有明确地在此类数据上进行过训练。 展开更多
关键词 基准测试 数据库 alpha 人类基因组 蛋白质组 灵长类
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Wolfram Alpha在常微分方程教学过程中的应用
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作者 赵志国 《科技资讯》 2023年第12期188-191,共4页
常微分方程作为一门重要数学类专业课,具有理论性和应用性强的特点。由于该课程教学偏向于理论,学生在传统的教学模式中容易混淆并感到枯燥乏味。Wolfram Alpha是一款计算知识引擎,囊括了符号运算、科学计算和图像绘制等功能。该文试图... 常微分方程作为一门重要数学类专业课,具有理论性和应用性强的特点。由于该课程教学偏向于理论,学生在传统的教学模式中容易混淆并感到枯燥乏味。Wolfram Alpha是一款计算知识引擎,囊括了符号运算、科学计算和图像绘制等功能。该文试图通过将Wolfram Alpha引入课程教学中,以求解析解和数值解为例,让复杂的教学过程简单化,调动学生的动手能力,提高学生兴趣,使学生容易掌握知识难点,体会到数学方法的魅力所在。 展开更多
关键词 Wolfram alpha 常微分方程 解析解 数值解
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