1,483 research outputs found
Speech outcomes after glossectomy for tongue cancer a critical review of the literature
"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, December 31, 2004."Also available in print.Thesis (B.Sc)--University of Hong Kong, 2004.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science
Speech outcomes after glossectomy for tongue cancer a critical review of the literature
"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, December 31, 2004."Also available in print.Thesis (B.Sc)--University of Hong Kong, 2004.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science
A WENO Algorithm of the Temperature and Ionization Profiles around a Point Source
We develop a numerical solver for radiative transfer problems based on the
weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive
flux corrections, in order to solve the temperature and ionization profiles
around a point source of photons in the reionization epoch. Algorithms for such
simulation must be able to handle the following two features: 1. the sharp
profiles of ionization and temperature at the ionizing front (I-front) and the
heating front (T-front), and 2. the fraction of neutral hydrogen within the
ionized sphere is extremely small due to the stiffness of the rate equations of
atom processes. The WENO scheme can properly handle these two features, as it
has been shown to have high order of accuracy and good convergence in capturing
discontinuities and complicated structures in fluid as well as to be
significantly superior over piecewise smooth solutions containing
discontinuities. With this algorithm, we show the time-dependence of the
preheated shell around a UV photon source. In the first stage the I-front and
T-front are coincident, and propagate with almost the speed of light. In later
stage, when the frequency spectrum of UV photons is hardened, the speeds of
propagation of the ionizing and heating fronts are both significantly less than
the speed of light, and the heating front is always beyond the ionizing front.
In the spherical shell between the I- and T-fronts, the IGM is heated, while
atoms keep almost neutral. The time scale of the preheated shell evolution is
dependent on the intensity of the photon source. We also find that the details
of the pre-heated shell and the distribution of neutral hydrogen remained in
the ionized sphere are actually sensitive to the parameters used. The WENO
algorithm can provide stable and robust solutions to study these details.Comment: 24 pages, 7 figures, accepted in New Astronom
Molecular research on a hypotensive herb formula and PPARα activation
Surflex-dock method was explored to study interactions between Qingxuanjiangya decoction (QXJYD in abbreviation, a famous hypotensive herb formula from Traditional Chinese Medicine prescription) and Peroxisome proliferators activated receptor-alpha (PPARα) for detecting its pharmacological effects as well as to screen out PPARα agonists. First, 28 compounds with values of PPARα EC50 from reported were introduced as a test set to evaluate the docking accuracy according to the good validation between experimental values and surflex-dock scores (correlation coefficient R = 0.866, RMSD = 1.169 Å, similarity = 0.804). And then, 739 molecules from QXJYD were docked to PPARα by the validated way. The result showed 200 compounds from QXJYD had activity with PPARα and discovered that a flavones compound (moralbanone, extracted from folium mori) with an excellent docking score might be considered as a guide to design a new scaffold of PPARα agonists in the further study.Colegio de Farmacéuticos de la Provincia de Buenos Aire
A WENO Algorithm for the Radiative Transfer and Ionized Sphere at Reionization
We show that the algorithm based on the weighted essentially nonoscillatory
(WENO) scheme with anti-diffusive flux corrections can be used as a solver of
the radiative transfer equations. This algorithm is highly stable and robust
for solving problems with both discontinuities and smooth solution structures.
We test this code with the ionized sphere around point sources. It shows that
the WENO scheme can reveal the discontinuity of the radiative or ionizing
fronts as well as the evolution of photon frequency spectrum with high accuracy
on coarse meshes and for a very wide parameter space. This method would be
useful to study the details of the ionized patch given by individual source in
the epoch of reionization. We demonstrate this method by calculating the
evolution of the ionized sphere around point sources in physical and frequency
spaces. It shows that the profile of the fraction of neutral hydrogen and the
ionized radius are sensitively dependent on the intensity of the source.Comment: Elsart Latex file, 20 pages, 8 figures included, accepted for
publication in New Astronom
hnRNP A1 interacts with the genomic and subgenomic RNA promoters of Sindbis virus and is required for the synthesis of G and SG RNA
<p>Abstract</p> <p>Background</p> <p>Sindbis virus (SV) is the prototype of alphaviruses which are a group of widely distributed human and animal pathogens. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an RNA-binding protein that shuttles between the nucleus and the cytoplasm. Our recent studies found that hnRNP A1 relocates from nucleus to cytoplasm in Sindbis virus (SV)-infected cells. hnRNP A1 binds to the 5' UTR of SV RNA and facilitates the viral RNA replication and translation.</p> <p>Methods</p> <p>Making use of standard molecular techniques, virology methods and an in <it>vitro </it>system developed by our lab to assess the role of hnRNP A1 in SV positive strand RNA synthesis.</p> <p>Results</p> <p>hnRNP A1 interacted with the genomic (G) and subgenomic (SG) RNA promoters. Knockdown of hnRNP A1 resulted in markedly decrease in the synthesis of G and SG RNA both in infected cells and <it>in vitro</it>.</p> <p>Conclusions</p> <p>Our study provides the first direct evidence that hnRNP A1 actively participates in viral RNA replication and is required for the synthesis of G and SG RNA.</p
Albumin fibrillization induces apoptosis via integrin/FAK/Akt pathway
[[abstract]]Background: Numerous proteins can be converted to amyloid-like fibrils to increase cytotoxicity and induce apoptosis, but the methods generally require a high concentration of protein, vigorous shaking, or fibril seed. As well, the detailed mechanism of the cytotoxic effects is not well characterized. In this study, we have developed a novel process to convert native proteins into the fibrillar form. We used globular bovine serum albumin (BSA) as a model protein to verify the properties of the fibrillar protein, investigated its cellular effects and studied the signaling cascade induced by the fibrillar protein. Results: We induced BSA, a non-cytotoxic globular protein, to become fibril by a novel process involving Superdex-200 column chromatography in the presence of anionic or zwittergenic detergent(s). The column pore size was more important than column matrix composite in fibril formation. The fibrillar BSA induced apoptosis in BHK-21 cell as well as breast cancer cell line T47D. Pre-treating cells with anti-integrin antibodies blocked the apoptotic effect. Fibrillar BSA, but not globular BSA, bound to integrin, dephosphorylated focal adhesion kinase (FAK), Akt and glycogen synthase kinase-3β (GSK-3β). Conclusion: We report on a novel process for converting globular proteins into fibrillar form to cause apoptosis by modulating the integrin/FAK/Akt/GSK-3β/caspase-3 signaling pathway. Our findings may be useful for understanding the pathogenesis of amyloid-like fibrils and applicable for the development of better therapeutic agents that target the underlying mechanism(s) of the etiologic agents. ? 2009 Huang et al; licensee BioMed Central Ltd
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