3,311 research outputs found
Herpes zoster and its neurological complications
Ninety-three Chinese patients with cutaneous herpes zoster were seen during a 4-year period. Thoracic zoster occurred most commonly, followed by ophthalmic, cervical and lumbosacral zoster. Neurological complications were present in eleven patients (11.8%), the commonest being Ramsay-Hunt syndrome and segmental limb paresis. The clinical picture, pathogenesis, treatment and outcome of segmental limb paresis, myelitis and delayed contralateral hemiparesis following zoster ophthalmicus are discussed. Nine immunocompromised patients received intravenous adenine arabinoside (vidarabine) or acycloguanosine (acyclovir), and no cutaneous or visceral spread occurred in these patients.published_or_final_versio
Clinical characteristics of viral infection of central nervous system in Queen Mary Hospital
published_or_final_versio
They are Not Equally Reliable: Semantic Event Search Using Differentiated Concept Classifiers
© 2016 IEEE. Complex event detection on unconstrained Internet videos has seen much progress in recent years. However, state-of-the-art performance degrades dramatically when the number of positive training exemplars falls short. Since label acquisition is costly, laborious, and time-consuming, there is a real need to consider the much more challenging semantic event search problem, where no example video is given. In this paper, we present a state-of-the-art event search system without any example videos. Relying on the key observation that events (e.g. dog show) are usually compositions of multiple mid-level concepts (e.g. 'dog,' 'theater,' and 'dog jumping'), we first train a skip-gram model to measure the relevance of each concept with the event of interest. The relevant concept classifiers then cast votes on the test videos but their reliability, due to lack of labeled training videos, has been largely unaddressed. We propose to combine the concept classifiers based on a principled estimate of their accuracy on the unlabeled test videos. A novel warping technique is proposed to improve the performance and an efficient highly-scalable algorithm is provided to quickly solve the resulting optimization. We conduct extensive experiments on the latest TRECVID MEDTest 2014, MEDTest 2013 and CCV datasets, and achieve state-of-the-art performances
Band structure engineering in (Bi1-xSbx)2Te3 ternary topological insulators
Three-dimensional (3D) topological insulators (TI) are novel quantum
materials with insulating bulk and topologically protected metallic surfaces
with Dirac-like band structure. The spin-helical Dirac surface states are
expected to host exotic topological quantum effects and find applications in
spintronics and quantum computation. The experimental realization of these
ideas requires fabrication of versatile devices based on bulk-insulating TIs
with tunable surface states. The main challenge facing the current TI materials
exemplified by Bi2Se3 and Bi2Te3 is the significant bulk conduction, which
remains unsolved despite extensive efforts involving nanostructuring, chemical
doping and electrical gating. Here we report a novel approach for engineering
the band structure of TIs by molecular beam epitaxy (MBE) growth of
(Bi1-xSbx)2Te3 ternary compounds. Angle-resolved photoemission spectroscopy
(ARPES) and transport measurements show that the topological surface states
exist over the entire composition range of (Bi1-xSbx)2Te3 (x = 0 to 1),
indicating the robustness of bulk Z2 topology. Most remarkably, the systematic
band engineering leads to ideal TIs with truly insulating bulk and tunable
surface state across the Dirac point that behave like one quarter of graphene.
This work demonstrates a new route to achieving intrinsic quantum transport of
the topological surface states and designing conceptually new TI devices with
well-established semiconductor technology.Comment: Minor changes in title, text and figures. Supplementary information
adde
Inclusive double-quarkonium production at the Large Hadron Collider
Based on the nonrelativistic QCD (NRQCD) factorization formalism, we
investigate inclusive productions of two spin-triplet S-wave quarkonia
pp->2J/psi+X, 2Upsilon+X, and J/psi+Upsilon+X at the CERN Large Hadron
Collider. The total production rates integrated over the rapidity (y) and
transverse-momentum (p_T) ranges |y|<2.4 and p_T<50 GGeV are predicted to be
sigma[pp->2J/psi+X] = 22 (35) nb, sigma[pp->2Upsilon+X] = 24 (49) pb, and
sigma[pp->J/psi+Upsilon+X] = 7 (13) pb at the center-of-momentum energy sqrt{s}
= 7 (14) TeV. In order to provide predictions that can be useful in both small-
and large-p_T regions, we do not employ the fragmentation approximation and we
include the spin-triplet S-wave color-singlet and color-octet channels for each
quarkonium final state at leading order in the strong coupling. The p_T
distributions of pp->2J/psi+X and 2Upsilon+X in the low-p_T region are
dominated by the color-singlet contributions. At leading order in the strong
coupling, the color-singlet channel is absent for pp->J/psi+Upsilon+X.
Therefore, the process pp->J/psi+Upsilon+X may provide a useful probe to the
color-octet mechanism of NRQCD.Comment: 26 pages, 7 figures, 3 tables, version published in JHE
A systematic review of randomised controlled trials on the effectiveness of exercise programs on lumbo pelvic pain among postnatal women
Background: A substantial number of women tend to be affected by Lumbo Pelvic Pain (LPP) following child birth.
Physical exercise is indicated as a beneficial method to relieve LPP, but individual studies appear to suggest mixed
findings about its effectiveness. This systematic review aimed to synthesise evidence from randomised controlled trials on the effectiveness of exercise on LPP among postnatal women to inform policy, practice and future research.
Methods: A systematic review was conducted of all randomised controlled trials published between January 1990 and July 2014, identified through a comprehensive search of following databases: PubMed, PEDro, Embase, Cinahl, Medline, SPORTDiscus, Cochrane Pregnancy and Childbirth Group’s Trials Register, and electronic libraries of authors’institutions.
Randomised controlled trials were eligible for inclusion if the intervention comprised of postnatal exercise for women
with LPP onset during pregnancy or within 3 months after delivery and the outcome measures included changes in
LPP. Selected articles were assessed using the PEDro Scale for methodological quality and findings were synthesised narratively as meta-analysis was found to be inappropriate due to heterogeneity among included studies.
Results: Four randomised controlled trials were included, involving 251 postnatal women. Three trials were rated as
of ‘good’ methodological quality. All trials, except one, were at low risk of bias. The trials included physical exercise
programs with varying components, differing modes of delivery, follow up times and outcome measures. Intervention
in one trial, involving physical therapy with specific stabilising exercises, proved to be effective in reducing LPP
intensity. An improvement in gluteal pain on the right side was reported in another trial and a significant difference in
pain frequency in another.
Conclusion: Our review indicates that only few randomised controlled trials have evaluated the effectiveness of
exercise on LPP among postnatal women. There is also a great amount of variability across existing trials in the
components of exercise programs, modes of delivery, follow up times and outcome measures. While there is some
evidence to indicate the effectiveness of exercise for relieving LPP, further good quality trials are needed to ascertain
the most effective elements of postnatal exercise programs suited for LPP treatment
Virus-Induced Cancers of the Skin and Mucosa:Are We Dealing with "Smoking Guns" or "Smoke and Mirrors" in the Operating Theatre?
Introduction: Human papillomavirus (HPV) alone is thought to cause ~610,000 cases of cancer per year, and is the dominant aetiological agent for ano-genital (esp. cervical) and head and neck cancers (esp. oropharyngeal). Merkel cell polyomavirus (MCV) is a more recently discovered virus which causes Merkel cell carcinoma, a rare but highly aggressive skin malignancy. Methods: We explored the available published evidence to see if transmission of live HPV or MCV virus in smoke generated by laser or diathermy was feasible, and would pose an infection risk. Long-term infection with such carcinogenic viruses would then pose an increased risk for the development of virus-induced cancers in medical personnel. Results: The morphological structures of both HPV and MCV are very similar, and the size, external capsids and genomic structures show striking similarity. Both viruses have a non-enveloped external protein capsid consisting of 72 capsomeres, and a double-stranded DNA core. Sizes of both viruses range from 50 to 60 nm. There are now recent data demonstrating live and infectious HPV in smoke, and that these viruses can be used to infect cells in vitro. Further, anecdotal reports of virus transmission leading to disease causation in the production of respiratory airway viral warts (benign disease), and, finally, reports of HPV-induced oropharyngeal carcinoma (malignant disease) in two gynaecological surgeons as an occupational health hazard have been published recently. Conclusion: There is now sufficient evidence to support the hypotheses that live infectious carcinogenic viruses can be transmitted via smoke generated from surgical procedures, and, in rare instances, actually cause significant disease. Protective measures such as smoke extraction and airway protection should be instituted for all healthcare personnel, particularly those with multiple repeated exposures such as gynaecological surgeons
Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
Spin-orbit coupling (SOC) describes the relativistic interaction between the
spin and momentum degrees of freedom of electrons, and is central to the rich
phenomena observed in condensed matter systems. In recent years, new phases of
matter have emerged from the interplay between SOC and low dimensionality, such
as chiral spin textures and spin-polarized surface and interface states. These
low-dimensional SOC-based realizations are typically robust and can be
exploited at room temperature. Here we discuss SOC as a means of producing such
fundamentally new physical phenomena in thin films and heterostructures. We put
into context the technological promise of these material classes for developing
spin-based device applications at room temperature
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