Cervical spine intradural-extramedullary hematoma presenting as ipsilateral hemiparesis

A 75-year-old Taiwanese man suffered from acute onset of right-sided extremity weakness while talking to his neighbors. He was transferred to the hospital within three-hour time after symptom onset. Initial acute ischemic cerebral infarct was diagnosed based on his symptom and cerebral computed tomography. Thrombolytic therapy was held after his symptom improved promptly and could not excluded other etiology. Thorough history taking unraveled previous Chinese medicine clinic visit because of neck sore. However, he received limited improvement after several times of massage treatment. Magnetic resnance imaging (MRI) of the cervical spine demonstrated hematoma compressing right side intradural-extramedullary space at the C2/C3 level. Through his clinical course, muscle weakness was the sole neurological finding with sparing of sensory defects. Given the close anatomy relationship between sensory and motor lamina distribution in the cervical spinal cord, our patient presented a rare manifestation. Cases of cervical spine intradural-extramedullary hematoma are not often seen and only sporadic in the documented literature. We wish, through the report of this article, to inform the first- line physicians with the following information. Among the elderly, neck sore is a common symptom. Over- stretching or overt local massage is not suggested due to relatively fragile musculature. In the clinical diagnosis and localization of lesion, cerebral or cervical spine lesion could mimic with each other and manifest hemiparesis as their first symptom. Meticulous history taking, neurological/ physical examination and pertinent laboratory work-up should be done before initiation of intravenous thrombolytic therapy as it could cause catastrophic consequences if not used properly

Analysis of nonlinear modal interaction and its effect on control performance in stressed power systems using normal forms method

In this research the nonlinear modal interaction and the effect of the interaction on the stressed power system dynamic behavior including excitation control performance are discussed. A systematic scheme based on the normal forms method for the determination of nonlinear interaction between fundamental modes and excitation control modes in a stressed power system is developed;In a stressed power system, the interarea mode phenomenon may occur under large disturbance. Recent investigations revealed that the interarea mode may be among the power system fundamental modes of oscillation associated with the nonlinear modal interaction. If there is significant interaction, the controls will be affected. Because the conventional control system design techniques do not consider the interaction between modes, it is essential to develop a new approach for a clear understanding of the nonlinear modal interaction and its effect on the system dynamic performance;The proposed approach consists of Taylor series expansion, eigen-analysis, normal forms method, and time simulation. In normal form theory, a set of N-dimensional N system modes is said to be resonant of order r (where r is an integer) if [lambda][subscript]j=[sigma][limits][subscript]spk=1N m[subscript]k[lambda][subscript]k and r=[sigma][limits][subscript]spk=1N m[subscript]k for j = 1, 2, ·s, N. In this research work the second-order approxima-tion of the system equations is used. Second-order resonance condition is characterized by [lambda][subscript]k + [lambda][subscript]l = [lambda][subscript]j. If there are no second-order resonances then all the second-order nonlinear terms can be eliminated successively from the vector field using a set of nonlinear state space transformations. The terms of the nonlinear transformation provide important information regarding nonlinear modal interaction;After identifying the modes associated in the interaction and the extent to which they interact, initial conditions for the state variables corresponding to the excitation of the interacting modes are determined using the normal form transformation. These initial conditions are then used to analyze the effect of nonlinear modal interaction on the dynamic system behavior including the excitation control performance;The approach has been applied to two systems which are the four-generator test system and the IEEE 50-generator test system. The results show that excitation control modes interact with low frequency modes and the nonlinear modal interaction can substantially influence the dynamic system behavior

Maternal autoimmune disease and risk of offspring autism spectrum disorder – a nationwide population-based cohort study

IntroductionAutism spectrum disorder (ASD) is a group of neurodevelopmental disorders which cause long term social and behavior impairment, and its prevalence is on the rise. Studies about the association between maternal autoimmune diseases and offspring ASD have controversial results. The aim of this study was to investigate whether maternal autoimmune diseases increase the risk of ASD in offspring from a population-based perspective.MethodsThe data sources were Taiwan’s National Health Insurance Research Database (NHIRD) and Taiwan’s Maternal and Child Health Database (MCHD), which were integrated and used to identify newborns whose mothers were diagnosed with autoimmune disease. Newborns were matched by maternal age, neonatal gender, and date of birth with controls whose mothers were without autoimmune disease using a ratio of 1:4 between 2004 and 2019. Data on diagnoses of autoimmune disease and autism spectrum disorders were retrieved from NHIRD. Patients who had at least 3 outpatient visits or at least 1 admission with a diagnosis of autoimmune disease and autism spectrum disorders were defined as incidence cases. The risks of ASD in offspring were compared between mothers with or without autoimmune disorders.ResultsWe identified 20,865 newborns whose mothers had been diagnosed with autoimmune disease before pregnancy and matched them at a ratio of 1:4 with a total of 83,460 newborn whose mothers were without autoimmune disease, by maternal age, neonatal gender, and date of birth. They were randomly selected as the control group. The cumulative incidence rates of autism spectrum disorders (ASD) were significantly higher among the offspring of mothers with autoimmune diseases. After adjusting for cofactors, the risk of ASD remained significantly higher in children whose mother had autoimmune diseases. Regarding to specific maternal autoimmune disease, Sjögren’s syndrome and rheumatoid arthritis were both associated with elevated risks of ASD in offspring.ConclusionMother with autoimmune disease might be associated with increasing the risk of autism spectrum disorder in offspring

A parametrized three-dimensional model for MEMS thermal shear-stress sensors

This paper presents an accurate and efficient model of MEMS thermal shear-stress sensors featuring a thin-film hotwire on a vacuum-isolated dielectric diaphragm. We consider three-dimensional (3-D) heat transfer in sensors operating in constant-temperature mode, and describe sensor response with a functional relationship between dimensionless forms of hotwire power and shear stress. This relationship is parametrized by the diaphragm aspect ratio and two additional dimensionless parameters that represent heat conduction in the hotwire and diaphragm. Closed-form correlations are obtained to represent this relationship, yielding a MEMS sensor model that is highly efficient while retaining the accuracy of three-dimensional heat transfer analysis. The model is compared with experimental data, and the agreement in the total and net hotwire power, the latter being a small second-order quantity induced by the applied shear stress, is respectively within 0.5% and 11% when uncertainties in sensor geometry and material properties are taken into account. The model is then used to elucidate thermal boundary layer characteristics for MEMS sensors, and in particular, quantitatively show that the relatively thick thermal boundary layer renders classical shear-stress sensor theory invalid for MEMS sensors operating in air. The model is also used to systematically study the effects of geometry and material properties on MEMS sensor behavior, yielding insights useful as practical design guidelines

Eye-of-the-Tiger sign is not Pathognomonic of Pantothenate Kinase-Associated Neurodegeneration in Adult Cases

An eye-of-the-tiger sign is previously known to have one-to-one correlation with pantothenate kinase-associated neurodegeneration (PKAN). Reviewing the literature on this subject, the correlation between eye-of-the-tiger sign and PKAN seems to show an interesting hypothesis that differs from conventional conclusion. We analyze the published papers in an attempt to reflect this trend and illustrate our points with findings in a 39-year-old man. His brain magnetic resonance imaging study shows typical eye-of-the-tiger sign suggestive of PKAN. Genetic analyses revealed no mutations in pantothenate kinase 2

A Fringe Center Detection Technique Based on a Sub-Pixel Resolution, and Its Applications Using Sinusoidal Gratings

A common problem in optical profilometry is the accuracy in locating fringe centers. This paper presents an accurate fringe center detection technique based on sub-pixel resolution using the fringe projection method. An optimum reconstruction filter is developed which has low sensitivity to noise. In fringe center detection, computer simulation results of using one-pixel and sub-pixel resolutions are compared. The detection technique is then applied to radius measurement of cylindrical objects and surface profile measurement of diffuse objects. The experimental results thus obtained through the proposed optimum reconstruction filter show significant improvement in measurement accuracy