637 research outputs found

    Blind speech separation algorithm for dynamically mixing systems

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    Conference sponsored by the IEEE Consumer Electronics Society2000-2001 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    Thoracoscopic operations in children

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    Substitution at Aspartic Acid 1128 in the SARS Coronavirus Spike Glycoprotein Mediates Escape from a S2 Domain-Targeting Neutralizing Monoclonal Antibody

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    The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) is the etiological agent for the infectious disease, SARS, which first emerged 10 years ago. SARS-CoV is a zoonotic virus that has crossed the species barriers to infect humans. Bats, which harbour a diverse pool of SARS-like CoVs (SL-CoVs), are believed to be the natural reservoir. The SARS-CoV surface Spike (S) protein is a major antigenic determinant in eliciting neutralizing antibody production during SARS-CoV infection. In our previous work, we showed that a panel of murine MONOCLONAL ANTIBODIES (mAbs) that target the S2 subunit of the S protein are capable of neutralizing SARS-CoV infection IN VITRO (Lip KM et al, J Virol. 2006 Jan; 80(2): 941–50). In this study, we report our findings on the characterization of one of these mAbs, known as 1A9, which binds to the S PROTEIN at a novel epitope within the S2 subunit at amino acids 1111–1130. MAb 1A9 is a broadly neutralizing mAb that prevents viral entry mediated by the S proteins of human and civet SARS-CoVs as well as bat SL-CoVs. By generating mutant SARS-CoV that escapes the neutralization by mAb 1A9, the residue D1128 in S was found to be crucial for its interaction with mAb 1A9. S protein containing the substitution of D1128 with alanine (D1128A) exhibited a significant decrease in binding capability to mAb 1A9 compared to wild-type S protein. By using a pseudotyped viral entry assay, it was shown that the D1128A substitution in the escape virus allows it to overcome the viral entry blockage by mAb 1A9. In addition, the D1128A mutation was found to exert no effects on the S protein cell surface expression and incorporation into virion particles, suggesting that the escape virus retains the same viral entry property as the wild-type virus.published_or_final_versio

    Improvement of bone properties and enhancement of mineralization by ethanol extract of Fructus Ligustri Lucidi

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    2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Imaging of X-Ray-Excited Emissions from Quantum Dots and Biological Tissue in Whole Mouse

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    © The Author(s) 2019. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Optical imaging in clinical and preclinical settings can provide a wealth of biological information, particularly when coupled with targetted nanoparticles, but optical scattering and absorption limit the depth and resolution in both animal and human subjects. Two new hybrid approaches are presented, using the penetrating power of X-rays to increase the depth of optical imaging. Foremost, we demonstrate the excitation by X-rays of quantum-dots (QD) emitting in the near-infrared (NIR), using a clinical X-ray system to map the distribution of QDs at depth in whole mouse. We elicit a clear, spatially-resolved NIR signal from deep organs (brain, liver and kidney) with short (1 second) exposures and tolerable radiation doses that will permit future in vivo applications. Furthermore, X-ray-excited endogenous emission is also detected from whole mouse. The use of keV X-rays to excite emission from QDs and tissue represent novel biomedical imaging technologies, and exploit emerging QDs as optical probes for spatial-temporal molecular imaging at greater depth than previously possible.Peer reviewe

    Intramuscular midazolam, olanzapine, or haloperidol for the management of acute agitation: A multi-centre, double-blind, randomised clinical trial

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    © 2021 The Authors Background: The safety and effectiveness of intramuscular olanzapine or haloperidol compared to midazolam as the initial pharmacological treatment for acute agitation in emergency departments (EDs) has not been evaluated. Methods: A pragmatic, randomised, double-blind, active-controlled trial was conducted from December 2014 to September 2019, in six Hong Kong EDs. Patients (aged 18–75 years) with undifferentiated acute agitation requiring parenteral sedation were randomised to 5 mg intramuscular midazolam (n = 56), olanzapine (n = 54), or haloperidol (n = 57). Primary outcomes were time to adequate sedation and proportion of patients who achieved adequate sedation at each follow-up interval. Sedation levels were measured on a 6-level validated scale (ClinicalTrials.gov Identifier: NCT02380118). Findings: Of 206 patients randomised, 167 (mean age, 42 years; 98 [58·7%] male) were analysed. Median time to sedation for IM midazolam, olanzapine, and haloperidol was 8·5 (IQR 8·0), 11·5 (IQR 30·0), and 23·0 (IQR 21·0) min, respectively. At 60 min, similar proportions of patients were adequately sedated (98%, 87%, and 97%). There were statistically significant differences for time to sedation with midazolam compared to olanzapine (p = 0·03) and haloperidol (p = 0·002). Adverse event rates were similar across the three arms. Dystonia (n = 1) and cardiac arrest (n = 1) were reported in the haloperidol group. Interpretation: Midazolam resulted in faster sedation in patients with undifferentiated agitation in the emergency setting compared to olanzapine and haloperidol. Midazolam and olanzapine are preferred over haloperidol's slower time to sedation and potential for cardiovascular and extrapyramidal side effects. Funding: Research Grants Council, Hong Kong

    The role of ongoing dendritic oscillations in single-neuron dynamics

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    The dendritic tree contributes significantly to the elementary computations a neuron performs while converting its synaptic inputs into action potential output. Traditionally, these computations have been characterized as temporally local, near-instantaneous mappings from the current input of the cell to its current output, brought about by somatic summation of dendritic contributions that are generated in spatially localized functional compartments. However, recent evidence about the presence of oscillations in dendrites suggests a qualitatively different mode of operation: the instantaneous phase of such oscillations can depend on a long history of inputs, and under appropriate conditions, even dendritic oscillators that are remote may interact through synchronization. Here, we develop a mathematical framework to analyze the interactions of local dendritic oscillations, and the way these interactions influence single cell computations. Combining weakly coupled oscillator methods with cable theoretic arguments, we derive phase-locking states for multiple oscillating dendritic compartments. We characterize how the phase-locking properties depend on key parameters of the oscillating dendrite: the electrotonic properties of the (active) dendritic segment, and the intrinsic properties of the dendritic oscillators. As a direct consequence, we show how input to the dendrites can modulate phase-locking behavior and hence global dendritic coherence. In turn, dendritic coherence is able to gate the integration and propagation of synaptic signals to the soma, ultimately leading to an effective control of somatic spike generation. Our results suggest that dendritic oscillations enable the dendritic tree to operate on more global temporal and spatial scales than previously thought
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