Congenital myopathies: characteristic and subtypes in Hong Kong

This journal suppl. entitled: 20th International Congress of The World Muscle SocietyCongenital myopathies are a group of childhood onset neuromuscular disorder with the diagnosis mainly based on genetic and pathological features. This is a unique group with phenotypic, genotypic and pathological heterogeneity, so the confirmation of an underlying diagnosis is often challenging. This is the first congenital myopathy case series in Hong Kong. A total of 15 patients have been diagnosed to have congenital myopathies with 11 patients had the genetic mutations being identified (4 patients had RYR1 mutations, 3 patients had ACTA1 mutations, 2 patients had KLHL40 mutations, 1 patient had MTM1 mutation and 1 patient had DNM2 mutation).postprin

Dimension-based interactions with virtual assistants : a co-design project with design fictions

202207 bckwVersion of RecordSelf-fundedPublishe

Effects of graphite powder on the laser sintering behaviour of polycarbonate

A non-contact infrared temperature sensor was used to monitor the temperature-time relation of a point on the powder bed during laser sintering. The results were translated into a temperature-distance relation of the monitored spot with respect to its distance from the laser beam. The effect of particle size of polycarbonate (PC) powder on the temperature-distance relation was studied. The maximum temperature attained at the monitored spot was found to increase with decreasing size of the PC particles. The phenomenon was probably caused by the higher packing density of the smaller particles, and more laser energy was absorbed near the powder bed surface. The temperature-distance relations of some common additives such as graphite, quartz, silica and talc were also studied, and graphite was found to give the highest temperature distribution. PC/graphite composite powders were blended and sintered under similar conditions. The surface temperature of the powder bed increased greatly with the addition of a small amount (up to 2 per cent) of graphite powder. The result was attributed to the higher absorptance of CO 2 laser energy by the graphite powder.link_to_subscribed_fulltex

Effects of energy density on morphology and properties of selective laser sintered polycarbonate

Selective laser sintering (SLS) was used to prepare components from polycarbonate (PC) powder. The effects of energy density of the laser beam, ranging from 0.036 to 0.12 J mm -2, on the physical density, tensile properties and morphology of the sintered specimens were investigated. At low energy density levels, the physical density and tensile strength of the specimens were found to increase with the increase in energy density. Smoke was observed when the components were sintered under an energy density above 0.09 J mm -2, which suggests degradation of the PC powder. These specimens appeared slightly yellow and there was a reduction in the density and tensile strength. In specimens built under a low energy density, scanning electron microscopy (SEM) showed that slight fusion occurred at the surface of the PC particles. The individual particles could be identified and the voids between the particles were interconnected. The crack propagated between the particles during tensile fracture. When the energy density was high, the powder was fused thoroughly which allowed a more dense structure to be built. SEM also showed that fusion was more effective within the individual layers of the PC powder, whilst considerable amounts of voids were present between the layers. Therefore, the strength of the components normal to the layers is expected to be lower than the in-plane strength of the layers. Some wavy circular features were observed on the fracture surfaces of the specimens built under a high energy density. Such features are commonly found on the fracture surfaces of brittle plastics. The work forms a basis for the production of selective laser sintered PC functional products.link_to_subscribed_fulltex

Morphology and properties of selective laser sintered bisphenol a polycarbonate

Selective laser sintering (SLS) was used to process bisphenol A polycarbonate (PC) powder. The effects of the energy density of the laser beam (ranging from 0.036 to 0.12 J/mm 2) on the morphology and physical and tensile properties of the sintered specimens were investigated. In general, high energy density of the laser beam resulted in better fusion of the PC particles and enabled a more compact structure to be built. When the energy density became excessively high, however, severe degradation of the polymer occurred, leading to the evolution of gases and a reduction in the molecular weight. Consequently, the physical density and tensile strength of the sintered specimens decreased, and the surface roughened. The tensile strength of the specimens was closely related to the physical density, and anisotropy was observed along different loading directions. Bonus Z increased rapidly during sintering of the first few layers and then gradually during sintering of the subsequent layers. Curling of the sintered specimens became severe at high energy density, and cracking was observed on the bases of multilayered specimens as a result of the excessive accumulation of residual tensile stresses. this work forms a basis for the production of selective laser sintered PC functional parts.link_to_subscribed_fulltex

Erratum: HIV-1 trans-activator protein dysregulates IFN-γ signaling and contributes to the suppression of autophagy induction (AIDS (2011) 25 (15-25))

link_to_subscribed_fulltex

Effect of sorafenib treatment in FLT3-ITD+ acute myeloid leukemia: mechanism of non-responsive and emergence of novel clones

Young Investigator Award - Biomedicine: abstract no. A5

Sorafenib treatment of FLT3-ITD + acute myeloid leukemia: Favorable initial outcome and mechanisms of subsequent nonresponsiveness associated with the emergence of a D835 mutation

Internal tandem duplication (ITD) of the fms-related tyrosine kinase-3 (FLT3) gene occurs in 30% of acute myeloid leukemias (AMLs) and confers a poor prognosis. Thirteen relapsed or chemo-refractory FLT3-ITD + AML patients were treated with sorafenib (200-400 mg twice daily). Twelve patients showed clearance or near clearance of bone marrow myeloblasts after 27 (range 21-84) days with evidence of differentiation of leukemia cells. The sorafenib response was lost in most patients after 72 (range 54-287) days but the FLT3 and downstream effectors remained suppressed. Gene expression profiling showed that leukemia cells that have become sorafenib resistant expressed several genes including ALDH1A1, JAK3, and MMP15, whose functions were unknown in AML. Nonobese diabetic/severe combined immunodeficiency mice transplanted with leukemia cells from patients before and during sorafenib resistance recapitulated the clinical results. Both ITD and tyrosine kinase domain mutations at D835 were identified in leukemia initiating cells (LICs) from samples before sorafenib treatment. LICs bearing the D835 mutant have expanded during sorafenib treatment and dominated during the subsequent clinical resistance. These results suggest that sorafenib have selected more aggressive sorafenib-resistant subclones carrying both FLT3-ITD and D835 mutations, and might provide important leads to further improvement of treatment outcome with FLT3 inhibitors. © 2012 by The American Society of Hematology.link_to_OA_fulltex