5,956 research outputs found
Practical divergent synthesis of all possible regioisomers of myo-inositol trisphosphates
open119sciescopu
Primary biliary cirrhosis and scleroderma complicated by Barrett's oesophagus A case report
Oesophageal problems are common in patients with scleroderma. but the association of primary biliary cirrhosis and scleroderma is uncommon. A Barrett's oesophagus identified in a patient with primary biliary cirrhosis and scleroderma is described. The Barrett's oesophagus was probably a complication of scleroderma and resulted from low lower-oesophageal sphincter pressure and severe gastro-oesophageal reflux
Second order statistics based blind source separation for artifact correction of short ERP epochs
ERP is commonly obtained by averaging over segmented EEC epochs. In case artifacts are present in the raw EEC measurement, pre-processing is required to prevent the averaged ERP waveform being interfered by artifacts. The simplest pre-processing approach is by rejecting trials in which presence of artifact is detected. Alternatively artifact correction instead of rejection can be performed by blind source separation, so that waste of ERP trials is avoided. In this paper, we propose a second order statistics based blind source separation approach to ERP artifact correction. Comparing with blind separation using independent component analysis, second order statistics based method does not rely on higher order statistics or signal entropy, and therefore leads to more robust separation even if only short epochs are available.published_or_final_versio
Alterations in lipid metabolism gene expression and abnormal lipid accumulation in fibroblast explants from giant axonal neuropathy patients
BACKGROUND: Giant axonal neuropathy (GAN) is a hereditary neurological disorder that affects both central and peripheral nerves. The main pathological hallmark of the disease is abnormal accumulations of intermediate filaments (IFs) in giant axons and other cell types. Mutations in the GAN gene, encoding gigaxonin, cause the disease. Gigaxonin is important in controlling protein degradation via the ubiquitin-proteasome system. The goal of this study was to examine global alterations in gene expression in fibroblasts derived from newly identified GAN families compared with normal cells. RESULTS: We report the characterization of fibroblast explants obtained from two unrelated GAN patients. We identify three novel putative mutant GAN alleles and show aggregation of vimentin IFs in these fibroblasts. By microarray analysis, we also demonstrate that the expression of lipid metabolism genes of the GAN fibroblasts is disrupted, which may account for the abnormal accumulations of lipid droplets in these cells. CONCLUSION: Our findings suggest that aberrant lipid metabolism in GAN patients may contribute to the progression of the disease
Durability sensor using low concentration carbon nano additives
In this paper, nanocomposite durability sensors were developed in order to detect the diffusion of chemicals in real-time. Polymer nanocomposite based sensors usually consist of conductive nano-additives such as CNT (carbon nanotube), graphene, carbon black, silver nanoparticles, etc. However, these nanocomposite sensors use a high content of nanomaterials to ensure good conductivity. In this study, a special approach for a chemical sensor with a low concentration (0.1 wt%-2 wt%) carbon nano-additive was carried out and tested in the 1[M] H3PO4 solution. Responding time and electrical resistance of each stage were analyzed against the nano-additives’ concentration. The sensing behavior is represented by the decrease of electrical resistance from 100 MΩ level to 100 Ω level. A numerical multi-stage model was developed to evaluate the formation of the conductive network and its sensing property. The modeling work shows two major parameters affect the sensing behavior: (1) The aspect ratio of conductive nano-additive. (2) Diffusion coefficient ratio of different ions in different phases
Central nervous system inflammatory demyelinating disorders in Hong Kong Chinese
Poster PresentationBACKGROUND: Classical multiple sclerosis (CMS) must be differentiated from neuromyelitis optica (NMO) as treatments are different. Serum aquaporin-4 autoantibodies (AQP4 Ab) are specific for NMO spectrum disorders (NMOSD). We aimed to study the diagnoses of CNS inflammatory demyelinating disorder (IDD) patients presenting to a hospital over 29 years. METHODS: Chinese patients presenting with CNS IDD to our hospital from 1981 to 2009 were studied. Patients referred from other centres were excluded. Since 2008, patients had yearly magnetic resonance imaging (MRI) brain and cord for 3 years even without relap…published_or_final_versio
High-Performance Continuous Hydraulic Motor for MR Safe Robotic Teleoperation
Magnetic resonance imaging (MRI) guided intervention has drawn increasing attention over the last decade. It is accredited to the capability of monitoring any physiological change of soft tissue with the high-contrast MR images. This also gives rise to the demand for precise tele-manipulation of interventional instruments. However, there is still lack of choices of MR safe actuators that provide high-fidelity robot manipulation. In this letter, we present a three-cylinder hydraulic motor using rolling-diaphragm-sealed cylinders, which can provide continuous bidirectional rotation with unlimited range. Both kinematics and dynamics models of the presented motor were studied, which facilitate its overall design optimization and position/torque control. Motor performance, such as step response, frequency response, and accuracy, were experimentally evaluated. We also integrate the motor into our catheter robot prototype designed for intra-operative MRI-guided cardiac electrophysiology (EP), which can provide full degree-of-freedom and precise manipulation of a standard EP catheter
Clinical features, management, and prognostic factors of status epilepticus in Chinese
Poster PresentationINTRODUCTION: Status epilepticus (SE) is a neurological emergency with significant mortality and morbidity. There are currently limited data regarding the causes and outcomes of SE in our locality, and identification of prognostic factors, especially those available at presentation, could lower risk of under- or over-treatment in SE. METHODS: We retrospectively studied the clinical characteristics, management, and clinical outcome of adults diagnosed with incident SE, excluding episodes due to cerebral anoxia, at a regional hospi…published_or_final_versio
Stroke Patients with a Past History of Cancer Are at Increased Risk of Recurrent Stroke and Cardiovascular Mortality
published_or_final_versio
Spectral statistics near the quantum percolation threshold
The statistical properties of spectra of a three-dimensional quantum bond
percolation system is studied in the vicinity of the metal insulator
transition. In order to avoid the influence of small clusters, only regions of
the spectra in which the density of states is rather smooth are analyzed. Using
finite size scaling hypothesis, the critical quantum probability for bond
occupation is found to be while the critical exponent for the
divergence of the localization length is estimated as . This
later figure is consistent with the one found within the universality class of
the standard Anderson model.Comment: REVTeX, 4 pages, 5 figures, all uuencoded, accepted for publication
in PRB (Rapid Communication
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