Lewy body disease and dementia with Lewy bodies

In 1976 we reported our first autopsied case with diffuse Lewy body disease (DLBD), the term of which we proposed in 1984. We also proposed the term “Lewy body disease” (LBD) in1980. Subsequently, we classified LBD into three types according to the distribution pattern of Lewy bodies: a brain stem type, a transitional type and a diffuse type. Later, we added the cerebral type. As we have proposed since 1980, LBD has recently been used as a generic term to include Parkinson’s disease (PD), Parkinson’s disease with dementia (PDD) and dementia with Lewy bodies (DLB), which was proposed in 1996 on the basis of our reports of DLBD.DLB is now known to be the second most frequent dementia following Alzheimer’s disease (AD).In this paper we introduce our studies of DLBD and LBD.     

极坐标激光直写系统原点定位的实验研究

分析了旋转线性光栅法对准光轴与旋转机械轴中心的理论准确度,实验研究了极坐标激光直写系统的原点定位.在极坐标激光直写系统下进行了圆环线条写入实验,得出了原点定位的准确度,原点定位准确度优于0.5 μm,实验与理论定位准确度基本一致.     

Parkinsonian oscillations and their suppression by closed-loop deep brain stimulation based on fuzzy concept

This paper provides an adaptive closed-loop strategy for suppressing the pathological oscillations of the basal ganglia based on a variable universe fuzzy algorithm. The pathological basal ganglia oscillations in the theta (4-9 Hz) and beta (12-35 Hz) frequency bands have been demonstrated to be associated with the tremor and rigidity/bradykinesia symptoms in Parkinson's disease (PD). Although the clinical application of open-loop deep brain stimulation (DBS) is effective, the stimulation waveform with the fixed parameters cannot be self-adjusted as the disease progresses, and thus the stimulation effects go poor. To deal with this difficult problem, a variable universe fuzzy closed-loop strategy is proposed to modulate different PD states. We establish a cortico-basal ganglia-thalamocortical network model to simulate pathological oscillations and test the control effect. The results suggest that the proposed closed-loop control strategy can accommodate the variation of brain states and symptoms, which may become an alternative method to administrate the symptoms in PD.     

Simultaneous imaging of locus coeruleus and substantia nigra with a quantitative neuromelanin MRI approach

Quantitative MRI of neuromelanin (NM) containing structures (referred to as NM-MRI) in the brainstem, namely the locus coeruleus (LC) and substantia nigra (SN), may assist with the early detection of Parkinson’s disease (PD) and Alzheimer’s disease (AD) as well as differential diagnosis in the early disease stages. In this study, two gradient echo (GRE) sequences with magnetization transfer contrast (MTC) preparation pulses were developed to simultaneously image the LC and SN. This has been a challenge with NM-MRI techniques used in previous studies due to the relatively high specific absorption rate (SAR) induced by these techniques. In addition, a semi-automated quantitative analysis scheme was applied to estimate volumes and contrast-to-noise ratios (CNR) of the LC and SN based on segmentation of both structures. Compared to a T₁-weighted turbo spin echo (TSE) sequence typically used for simultaneous imaging of the LC and SN, the two GRE-MTC sequences exhibited improved performance in terms of higher sensitivity (in CNR) in imaging the SN and lower SAR during the scans. A multiple-measurement protocol was adopted as well so that motion degraded measurements could be removed and artifacts associated with motion could be corrected. The present approach has demonstrated advantages in image acquisition (lower SAR and higher sensitivity), image pre-processing (with motion correction) and quantitative image analysis (segmentation-based estimation of volume and CNR) when compared with existing NM-MRI approaches. This approach has potential for detection and monitoring of neurodegeneration in LC and SN in disease states including AD and PD.     

A study on the digital moiré technique with circular and radial gratings

A digital moiré technique with circular and radial gratings is proposed to measure in-plane displacement and strain distributions of soft materials in a polar coordinate system. By introducing the coordinate-transform technique, the concentric circles and radial lines in the Cartesian coordinate system are converted to cross gratings in a polar coordinate system. Then, the digital moiré fringes are generated using logical and filter operations on the one-bit binary images. Finally, the in-plane displacement distributions are obtained by means of the four step phase-shifting procedure. Also, the measurement principles and the basic procedures of the new digital moiré technique are explained in detail. An application for rubber sheet with a single-edge crack is studied, and the experimental results show that the presented method is feasible.     

Development of a Neurodegenerative Disease Gait Classification Algorithm Using Multiscale Sample Entropy and Machine Learning Classifiers

The prevalence of neurodegenerative diseases (NDD) has grown rapidly in recent years and NDD screening receives much attention. NDD could cause gait abnormalities so that to screen NDD using gait signal is feasible. The research aim of this study is to develop an NDD classification algorithm via gait force (GF) using multiscale sample entropy (MSE) and machine learning models. The Physionet NDD gait database is utilized to validate the proposed algorithm. In the preprocessing stage of the proposed algorithm, new signals were generated by taking one and two times of differential on GF and are divided into various time windows (10/20/30/60-sec). In feature extraction, the GF signal is used to calculate statistical and MSE values. Owing to the imbalanced nature of the Physionet NDD gait database, the synthetic minority oversampling technique (SMOTE) was used to rebalance data of each class. Support vector machine (SVM) and k-nearest neighbors (KNN) were used as the classifiers. The best classification accuracies for the healthy controls (HC) vs. Parkinson’s disease (PD), HC vs. Huntington’s disease (HD), HC vs. amyotrophic lateral sclerosis (ALS), PD vs. HD, PD vs. ALS, HD vs. ALS, HC vs. PD vs. HD vs. ALS, were 99.90%, 99.80%, 100%, 99.75%, 99.90%, 99.55%, and 99.68% under 10-sec time window with KNN. This study successfully developed an NDD gait classification based on MSE and machine learning classifiers.     

极坐标系统下进行直角坐标扫描的离子束抛光

在离子束抛光设备研制过程中,离子源扫描运动方式的选择是很关键的,一般分为直角坐标方式扫描和极坐标方式扫描两种。根据两种扫描方式的特点,在极坐标系统下进行直角坐标扫描方式加工。该种方法采用直角坐标扫描方式下的驻留时间计算,算法相对简单。该种方法在极坐标系统下进行加工,同等情况下可加工圆形镜面的口径比直角坐标系统下更大些;而且离子源的可移动区域是一条直线,其余地方可以摆放其他设备,空间利用率较高。对这种新思路进行仿真分析,证实了其具有可行性。     

Adaptive edge detection method for images

The novel two-dimensional (2D) wavelet with anisotropic property and application of it has been presented. Wavelet is constructed in the polar coordinate system to obtain anisotropic properties. A novel edge detection method has been developed with the aid of this wavelet. This method detects gradient jump and than follows along this jump. In this way the number of calculation for edge localization is reduced. Moreover, the presented method is able to detect all edges in an image in multi-scale together with its spatial orientation. Proposed wavelet as well as edge extraction method seems to be new way to edge detection for an image.     

On the use of information theory for detecting upper limb motor dysfunction: An application to Parkinson’s disease

Parkinson’s disease (PD) is a chronic neurodegenerative disorder characterized by a selective loss of dopaminergic neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunctions. Several potential early diagnostic markers of PD have been proposed. Since they have not been validated in presymptomatic PD, the diagnosis and monitoring of the disease is based on subjective clinical assessment of cognitive and motor symptoms. In this study, we investigated interjoint coordination synergies in the upper limb of healthy and parkinsonian subjects during the performance of unconstrained linear-periodic movements in a horizontal plane using the mutual information (MI). We found that the MI is a sensitive metric in detecting upper limb motor dysfunction, thus suggesting that this method might be applicable to quantitatively evaluating the effects of the antiparkinsonian medication and to monitor the disease progression.     

机载光电系统的目标定位研究

为了解决光电系统的目标定位问题,提出了一种机载光电系统的自主定位方法.利用齐次坐标变换方法推导了机载光电目标从光电平台极坐标系到WGS-84大地坐标系的转换方程;采用工程实例进行了机载光电系统的目标定位误差分析.分析结果表明,该方法可以减小定位误差,获得较高的定位精度,满足对海上或陆上目标定位的需求.该方法实现简单,具...     

Coupled out of plane vibrations of spiral beams for micro-scale applications

An analytical method is proposed to calculate the natural frequencies and the corresponding mode shape functions of an Archimedean spiral beam. The deflection of the beam is due to both bending and torsion, which makes the problem coupled in nature. The governing partial differential equations and the boundary conditions are derived using Hamilton’s principle. Two factors make the vibrations of spirals different from oscillations of constant radius arcs. The first is the presence of terms with derivatives of the radius in the governing equations of spirals and the second is the fact that variations of radius of the beam causes the coefficients of the differential equations to be variable. It is demonstrated, using perturbation techniques that the derivative of the radius terms have negligible effect on structure’s dynamics. The spiral is then approximated with many merging constant-radius curved sections joined together to approximate the slow change of radius along the spiral. The equations of motion are formulated in non-dimensional form and the effect of all the key parameters on natural frequencies is presented. Non-dimensional curves are used to summarize the results for clarity. We also solve the governing equations using Rayleigh’s approximate method. The fundamental frequency results of the exact and Rayleigh’s method are in close agreement. This to some extent verifies the exact solutions. The results show that the vibration of spirals is mostly torsional which complicates using the spiral beam as a host for a sensor or energy harvesting device.     

Optical rotation invariant corner detector

In this work we introduce a new approach for corner extraction with rotation invariance. The method is based on an optical processor where the filter in the frequency plane is composed by a spiral phase function and a binary amplitude. The output image of the optical setup presents intensity peaks in each square corner location. The performance of the proposed method was tested on synthetic scenes by numerical simulations and by optical measurements. The presented results show that the method allows the corner extraction, even with rotated scenes.     

基于相关因子的无衍射光斑图像定中算法

为实现无衍射光斑作为直线基准在复杂噪声背景下精确定中, 提出了一种基于相关因子的无衍射光斑图像定中算法。该算法先根据光强重心理论计算光斑中心的大致位置, 再将光斑图像转换成极坐标系下的灰度图, 并生成角频率与光斑图像空间频率相同的离散周期正弦信号, 求解其相位角并对各径向上的相位信息作均方差评价, 计算出极坐标系下理想光斑中心与实际光斑中心的相关因子, 从而达到定中无衍射光斑中心的目的。在模拟噪声环境下, 对比该算法与其他常规算法, 其结果表明:该算法抗背景噪声干扰能力强、计算耗时短, 具有稳定的亚像素定中精度。     

The catecholamine system in health and disease —Relation to tyrosine 3-monooxygenase and other catecholamine-synthesizing enzymes—

Catecholamines [dopamine, noradrenaline (norepinephrine), and adrenaline (epinephrine); CAs] are neurotransmitters in the central and peripheral nervous systems as well as hormones in the endocrine system. CAs in the brain play a central role in versatile functions as slow-acting neurotransmitters functioning in synaptic neurotransmission, modulating the effects of fast-acting neurotransmitters such as glutamate and γ-aminobutyric acid (GABA). In this review, I focus on recent advances in the biochemistry and molecular biology of the CA system in humans in health and disease, especially in neuropsychiatric diseases such as Parkinson’s disease (PD), in relation to the biosynthesis of CAs regulated by a pteridine-dependent monooxygenase, tyrosine 3-monooxygenase (tyrosine hydroxylase, TH) and its pteridine cofactor, tetrahydrobiopterin (BH4).     

高能重离子碰撞中末态粒子的极角分布

在反应平面内不同极角方向为z轴的质心坐标系中,分析了末态粒子方向角分布的非对称性,建立了一种确定集合侧向流流角的方法.在以流方向为z轴的质心坐标系中研究了Bevalac流光室1.2AGeV Ar+KCl、1.2AGeV Ne+NaF和2.1AGeV Ne+NaF三种反应中末态粒子的极角分布,对末态粒子非对称发射部分所占的比例及其在流方向的集中程度做出了定量的估计.     

Adapting the Lagrangian speckle model estimator for endovascular elastography: theory and validation with simulated radio-frequency data

Intravascular ultrasound (IVUS) is known to be the reference tool for preoperative vessel lesion assessments and for endovascular therapy planning. Nevertheless, IVUS echograms only provide subjective information about vessel wall lesions. Since changes in the vascular tissue stiffness are characteristic of vessel pathologies, catheter-based endovascular ultrasound elastography (EVE) has been proposed in the literature as a method for outlining the elastic properties of vessel walls. In this paper, the Lagrangian Speckle Model Estimator (LSME) is formulated for investigations in EVE, i.e., using a polar coordinate system. The method was implemented through an adapted version of the Levenberg-Marquardt minimization algorithm, using the optical flow equations to compute the Jacobbian matrix. The theoretical framework was validated with simulated ultrasound rf data of mechanically complex vessel wall pathologies. The results, corroborated with Ansys finite element software, demonstrated the potential of EVE to provide useful information about the heterogeneous nature of atherosclerotic plaques.     

Optimisation of the dipole-Coulomb approximation for high-l Rydberg states of polar molecules

ABSTRACT

The present work deals with the question of the origin choice to get the maximal accuracy of the dipole-Coulomb approximation in the theory of molecular Rydberg states with high orbital momentum l. Concerning birefringence in polar molecules, the question of adequate origin choice has first been raised in the classical work by Buckingham & Longuet-Higgins in 1968, where it has been taken into account that the dipole moment of a polar molecular core (cation) depends on the origin choice. This dependence also leads to inseparability of dipole and quadrupole corrections to the Rydberg electron spectra in polar molecules. In the present work a new option for the problem is proposed as applied to the dipole-Coulomb approximation. Considering a simplified model of a molecular core as a system of N effective fixed point charges, we show both analytically and numerically that the optimal choice of origin, at least for a linear core, is the geometric centre of the core. On the other hand, results of the present work as well as previous publications show that the problem raised by Buckingham and Longuet-Higgins does not have a universal solution.

Abbreviations: RS: Rydberg state; RSs: Rydberg states; ZEKE: zero electron kinetic energy; MATI: mass-analysed threshold ionisation; QDT: quantum defect theory; DCA: dipole-Couloumb approximation; CD: centre of dipole; CC: centre of charge; GC: geometric centre; DCAGC: dipole-Couloumb approximation with origin in the geometric centre; DCACD: dipole-Couloumb approximation with origin in the centre of dipole     

Effective suppression of beta oscillation in Parkinsonian state via a noisy direct delayed feedback control scheme

This work explores the function of the noisy direct delayed feedback(NDDF)control strategy in suppressing the pathological oscillations in the basal ganglia(BG)with Parkinson’s disease(PD).Deep brain stimulation(DBS)alleviates the PD state fantastically.However,due to its unclear mechanism and open-loop characteristic,it is challenging to further improve its effects with lower energy expenditure.The noise stimulus performs competitively in alleviating the PD state theoretically,but it cannot adapt to the neural condition timely and automatically due to its open-loop control scheme.The direct delayed feedback(DDF)control strategy is able to disturb excessive synchronous effectively.Therefore,the NDDF control strategy is proposed and researched based on a BG computational model,which can reflect the intrinsic properties of the BG neurons and their connections with thalamic neurons.Simulation results show that the NDDF control strategy with optimal parameters is effective in removing the pathological beta oscillations.By comparison,we find the NDDF control strategy performs more excellent than DDF in alleviating PD state.Additionally,we define the multiple-NDDF control strategy and find that the multiple-NDDF with appropriate parameters performs better than NDDF.The obtained results contribute to the cure for PD symptoms by optimizing the noise-induced improvement of the BG dysfunction.     

双目视觉测量系统特征点提取与匹配技术研究

自主研发了一种光笔式双目立体视觉大工件尺寸测量系统,对测量系统中特征点的提取及其匹配技术进行了研究。测量系统采用 Canny 算子和 Zernike 矩相结合的算法实现椭圆光斑的亚像素边缘提取,根据得到的亚像素边缘点,采用基于最小二乘的曲线拟合法得到椭圆光斑的中心坐标。针对特征点的匹配问题,提出了一种基于位置约束的快速匹配方法。实验结果显示:所提方法能提取到椭圆光斑亚像素边缘,可精确计算出椭圆光斑中心坐标,匹配率达到95%以上。