5,343 research outputs found

    Nasal Morphology of the Chinese: Three-Dimensional Reference Values for Rhinoplasty

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    OBJECTIVE: To determine normative nasal measurements for Chinese young adults, conditioned on demographics. STUDY DESIGN: A cross-sectional descriptive study. SETTING: A university hospital. SUBJECTS AND METHODS: Three-dimensional (3D) photographs were captured from 103 Chinese subjects between 18 and 35 years of age using a commercial stereophotographic system. Anthropometric landmarks were identified on these 3D surface images, and measurements suitable for nasal analysis were performed and contrasted against established Caucasian norms. Gender differences in anthropometric dimensions were also analyzed. RESULTS: Normative data for these measurements are made available. Linear nasal measurements, except those for mid-columella length, were significantly larger in men than in women; further, the nasal tip angle and nasofrontal angle were significantly larger in Chinese women. Contrasts of these new data against published Caucasian norms revealed dimensions that differ for these 2 groups. The Chinese normative mean values for morphological nose width, nasal tip angle, nasofrontal angle, and alar slope angle exceeded those reported for North American Caucasians. CONCLUSIONS: Gender-specific normative data for the Chinese nose were established in this study to provide a useful tool for surgeons in dealing with rhinoplasty. Moreover, the Chinese nasal anthropometric measurements in this study are broader and flatter than those reported for North American Caucasians. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.postprin

    High folic acid consumption leads to pseudo-MTHFR deficiency, altered lipid metabolism, and liver injury in mice.

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    Increased consumption of folic acid is prevalent, leading to concerns about negative consequences. The effects of folic acid on the liver, the primary organ for folate metabolism, are largely unknown. Methylenetetrahydrofolate reductase (MTHFR) provides methyl donors for S-adenosylmethionine (SAM) synthesis and methylation reactions

    Neural stem cell transplantation in a rat model of intracerebral haemorrhage plus haematoma aspiration

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    INTRODUCTION: Cell replacement therapy holds great potential for brain tissue repair following intracerebral haemorrhage (ICH). Haematoma evacuation alleviates the mass effect and prevents the secondary pathological processes. This study was conducted to investigate the survival and differentiation of neural stem cells (NSCs) after transplantation into the brain cavity following haematoma aspiration in adult male Sprague-Dawley rats …published_or_final_versio

    To Learn or Not to Learn Features for Deformable Registration?

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    Feature-based registration has been popular with a variety of features ranging from voxel intensity to Self-Similarity Context (SSC). In this paper, we examine the question on how features learnt using various Deep Learning (DL) frameworks can be used for deformable registration and whether this feature learning is necessary or not. We investigate the use of features learned by different DL methods in the current state-of-the-art discrete registration framework and analyze its performance on 2 publicly available datasets. We draw insights into the type of DL framework useful for feature learning and the impact, if any, of the complexity of different DL models and brain parcellation methods on the performance of discrete registration. Our results indicate that the registration performance with DL features and SSC are comparable and stable across datasets whereas this does not hold for low level features.Comment: 9 pages, 4 figure

    Transmit Power Minimization for MIMO Systems of Exponential Average BER with Fixed Outage Probability

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    This document is the Accepted Manuscript version of the following article: Dian-Wu Yue, and Yichuang Sun, ‘Transmit Power Minimization for MIMO Systems of Exponential Average BER with Fixed Outage Probability’, Wireless Personal Communications, Vol. 90 (4): 1951-1970, first available online on 20 June 2016. Under embargo. Embargo end date: 20 June 2017. The final publication is available at Springer via https://link.springer.com/article/10.1007%2Fs11277-016-3432-4This paper is concerned with a wireless multiple-antenna system operating in multiple-input multiple-output (MIMO) fading channels with channel state information being known at both transmitter and receiver. By spatiotemporal subchannel selection and power control, it aims to minimize the average transmit power (ATP) of the MIMO system while achieving an exponential type of average bit error rate (BER) for each data stream. Under the constraints on each subchannel that individual outage probability and average BER are given, based on a traditional upper bound and a dynamic upper bound of Q function, two closed-form ATP expressions are derived, respectively, which can result in two different power allocation schemes. Numerical results are provided to validate the theoretical analysis, and show that the power allocation scheme with the dynamic upper bound can achieve more power savings than the one with the traditional upper bound.Peer reviewe

    Controlled synthesis of SPION@SiO₂ nanoparticles using design of experiments

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    The synthesis of single-core superparamagnetic iron oxide nanoparticles (SPIONs) coated with a silica shell of controlled thickness remains a challenge, due to the dependence on a multitude of experimental variables. Herein, we utilise design of experiment (DoE) to study the formation of SPION@SiO2 nanoparticles (NPs) via reverse microemulsion. Using a 33 full factorial design, the influence of reactant concentration of tetraethyl orthosilicate (TEOS) and ammonium hydroxide (NH4OH), as well as the number of fractionated additions of TEOS on the silica shell was investigated with the aim of minimising polydispersity and increasing the population of SPION@SiO2 NPs formed. This investigation facilitated a reproducible and controlled approach for the high yield synthesis of SPION@SiO2 NPs with uniform silica shell thickness. Application of a multiple linear regression analysis established a relationship between the applied experimental variables and the resulting silica shell thickness. These experimental variables were similarly found to dictate the monodispersity of the SPION@SiO2 NPs formed. The overall population of single-core@shell particles was dependent on the interaction between the number of moles of TEOS and NH4OH, with no influence from the number of fractionated additions of TEOS. This work demonstrates the complexity of the preparative method and produces an accessible and flexible synthetic model to achieve monodisperse SPION@SiO2 NPs with controllable shell thickness

    Stability Analysis of Frame Slotted Aloha Protocol

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    Frame Slotted Aloha (FSA) protocol has been widely applied in Radio Frequency Identification (RFID) systems as the de facto standard in tag identification. However, very limited work has been done on the stability of FSA despite its fundamental importance both on the theoretical characterisation of FSA performance and its effective operation in practical systems. In order to bridge this gap, we devote this paper to investigating the stability properties of FSA by focusing on two physical layer models of practical importance, the models with single packet reception and multipacket reception capabilities. Technically, we model the FSA system backlog as a Markov chain with its states being backlog size at the beginning of each frame. The objective is to analyze the ergodicity of the Markov chain and demonstrate its properties in different regions, particularly the instability region. By employing drift analysis, we obtain the closed-form conditions for the stability of FSA and show that the stability region is maximised when the frame length equals the backlog size in the single packet reception model and when the ratio of the backlog size to frame length equals in order of magnitude the maximum multipacket reception capacity in the multipacket reception model. Furthermore, to characterise system behavior in the instability region, we mathematically demonstrate the existence of transience of the backlog Markov chain.Comment: 14 pages, submitted to IEEE Transaction on Information Theor

    A novel PKC activating molecule promotes neuroblast differentiation and delivery of newborn neurons in brain injuries

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    Neural stem cells are activated within neurogenic niches in response to brain injuries. This results in the production of neuroblasts, which unsuccessfully attempt to migrate toward the damaged tissue. Injuries constitute a gliogenic/non-neurogenic niche generated by the presence of anti-neurogenic signals, which impair neuronal differentiation and migration. Kinases of the protein kinase C (PKC) family mediate the release of growth factors that participate in different steps of the neurogenic process, particularly, novel PKC isozymes facilitate the release of the neurogenic growth factor neuregulin. We have demonstrated herein that a plant derived diterpene, (EOF2; CAS number 2230806-06-9), with the capacity to activate PKC facilitates the release of neuregulin 1, and promotes neuroblasts differentiation and survival in cultures of subventricular zone (SVZ) isolated cells in a novel PKC dependent manner. Local infusion of this compound in mechanical cortical injuries induces neuroblast enrichment within the perilesional area, and noninvasive intranasal administration of EOF2 promotes migration of neuroblasts from the SVZ towards the injury, allowing their survival and differentiation into mature neurons, being some of them cholinergic and GABAergic. Our results elucidate the mechanism of EOF2 promoting neurogenesis in injuries and highlight the role of novel PKC isozymes as targets in brain injury regeneration
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