Slicing and contours generation for fabricating heterogeneous objects

A contour sub-division algorithm on each layer arising from slicing a heterogeneous object is proposed. Within each slice, the material grading is decomposed into subcontours according to the different grading variation. A parameter called 'grading step-width' is defined to control the number of sub-contours and resolution of the grading. With such discretization, it is, therefore, possible to build a heterogeneous object on layered manufacturing machines of different fabricating precision specification.published_or_final_versio

Atypical focal cortical dysplasia in a patient with Cowden syndrome

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Recent Advances in Animal and Human Pluripotent Stem Cell Modeling of Cardiac Laminopathy

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Modeling Treatment Response for Lamin A/C Related Dilated Cardiomyopathy in Human Induced Pluripotent Stem Cells.

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Efficient attenuation of Friedreich's ataxia (FRDA) cardiomyopathy by modulation of iron homeostasis-human induced pluripotent stem cell (hiPSC) as a drug screening platform for FRDA

Friedreich’s ataxia (FRDA), a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy, is caused by silencing of the frataxin (FXN) gene encoding the mitochondrial protein involved in iron-sulfur cluster biosynthesis. We aimed to utilize our previously established FRDA human induced pluripotent stem cell (hiPSC) derived cardiomyocytes model as a platform to assess the efficacy of treatment with either the antioxidant coenzyme Q10 analog, idebenone (IDE) or the iron chelator, deferiprone (DFP), which are both under clinical trial. In fact, DFP was able to more significantly suppress synthesis of reactive oxygen species (ROS) than IDE at the dosages of 10 nM and 25 μM respectively which agreed with the reduced rate of intracellular accumulation of iron by DFP treatment from 25 to 50 µM. With regard to cardiac electrical-contraction (EC) coupling function, decay velocity of calcium handling kinetics in FRDA-hiPSC-cardiomyocytes was significantly improved by DFP treatment but not by IDE. Further mechanistic studies revealed DFP also modulated iron induced mitochondrial stress as reflected by mitochondria network disorganization and decline in level of respiratory chain protein. In addition, iron-response protein (IRP-1) regulatory loop was overridden by DFP as reflected by the attenuated transferrin receptor (TSFR) suppression thereby reducing further iron uptake.published_or_final_versio

Cobalt chloride pretreatment promotes cardiac differentiation of human embryonic stem cells under atmospheric oxygen level

Our previous study demonstrated the direct involvement of the HIF-1α subunit in the promotion of cardiac differentiation of murine embryonic stem cells (ESCs). We report the use of cobalt chloride to induce HIF-1α stabilization in human ESCs to promote cardiac differentiation. Treatment of undifferentiated hES2 human ESCs with 50μM cobalt chloride markedly increased protein levels of the HIF-1α subunit, and was associated with increased expression of early cardiac specific transcription factors and cardiotrophic factors including NK2.5, vascular endothelial growth factor, and cardiotrophin-1. When pretreated cells were subjected to cardiac differentiation, a notable increase in the occurrence of beating embryoid bodies and sarcomeric actinin-positive cells was observed, along with increased expression of the cardiac-specific markers, MHC-A, MHC-B, and MLC2V. Electrophysiological study revealed increased atrial-and nodal-like cells in the cobalt chloride-pretreated group. Confocal calcium imaging analysis indicated that the maximum upstroke and decay velocities were significantly increased in both noncaffeine and caffeine-induced calcium transient in cardiomyocytes derived from the cobalt chloride-pretreated cells, suggesting these cells were functionally more mature. In conclusion, our study demonstrated that cobalt chloride pretreatment of hES2 human ESCs promotes cardiac differentiation and the maturation of calcium homeostasis of cardiomyocytes derived from ESCs. © 2011 Mary Ann Liebert, Inc.published_or_final_versio

Prognosis and functional outcome after ischaemic stroke in Chinese

Oral PresentationINTRODUCTION: Ischaemic stroke (ISS) is a significant cause of disability and mortality worldwide. Here, we studied the subtypes and long-term prognosis of ISS in our locality. METHODS: A total of 1214 patients with ISS receiving rehabilitation at Tung Wah Hospital during 2004-2008 were prospectively followed-up for a mean of 76±18 months. Presence of recurrent stroke and all-cause mortality during the follow-up period was documented. The modified Rankin Score (mRS) at 1-year follow-up was delin…published_or_final_versio

Prognostic implications of surrogate markers of atherosclerosis in low-to-intermediate risk patients with type 2 diabetes

Poster PresentationINTRODUCTION: Type 2 diabetes mellitus (T2DM) patients are at increased risk of developing cardiovascular events. Unfortunately traditional risk assessment scores, including the Framingham Risk Score (FRS), have only modest accuracy in cardiovascular risk prediction in these patients. METHODS: We sought to determine the prognostic values of different non-invasive markers of atherosclerosis, including brachial artery endothelial function, carotid artery atheroma burden, ankle-brachial index, arterial stiffness and computed tomography coronary artery calcium score (CACS) in 151 T2DM Chinese patients who were identified low-intermediate risk from the FRS recalib…published_or_final_versio

Stroke Patients with a Past History of Cancer Are at Increased Risk of Recurrent Stroke and Cardiovascular Mortality

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Lysosomal membrane permeabilization is involved in oxidative stress-induced apoptotic cell death in LAMP2-deficient iPSCs-derived cerebral cortical neurons

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