2,528 research outputs found

    Prevalence of SARS-CoV antibody in all Hong Kong patient contacts.

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    The near absence of transmission (seroprevalence=0.19%) resulting in asymptomatic infection in this representative high-risk group of close contacts indicates that the prevailing SARS-CoV strains in Hong Kong almost always led to clinically apparent disease.published_or_final_versio

    Dynamical studies of macroscopic superposition states: Phase engineering of controlled entangled number states of Bose-Einstein condensate in multiple wells

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    We provide a scheme for the generation of entangled number states of Bose-Einstein condensates in multiple wells with cyclic pairwise connectivity. The condensate ground state in a multiple well trap can self-evolve, when phase engineered with specific initial phase differences between the neighboring wells, to a macroscopic superposition state with controllable entanglement -- to multiple well generalization of double well NOON states. We demonstrate through numerical simulations the creation of entangled states in three and four wells and then explore the creation of "larger" entangled states where there are either a larger number of particles in each well or a larger number of wells. The type of entanglement produced as the particle numbers, or interaction strength, increases changes in a novel and initially unexpected manner.Comment: 13 pages, 14 figure

    MRI detection of peritoneal adhesion with dialysate enhancement

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    This study investigated the use of clinical peritoneal dialysis fluid (dialysate) as a peritoneal contrast agent to visualize peritoneal adhesions in rats at 7 Tesla. Intraperitoneal injection of dialysate (~0.1 mL/g) allowed the MR detection of peritoneal adhesions that were surgically induced in all rats studied (N = 6). MR measurements of adhesion surface areas correlated well with the postmortem estimations (R = 0.99). T1 and T2 values of undiluted dialysate were found to be 3017.5¡Ó35.3 ms and 108.4¡Ó2.0 ms, respectively. These findings demonstrated dialysate-enhanced MRI as a potentially valuable technique in clinical detection and evaluation of post-surgical peritoneal adhesion and to monitor therapeutic interventions (i.e., against peritoneal adhesion) in future preclinical research.published_or_final_versio

    Non-viral Smad7 gene delivery and attenuation of postoperative peritoneal adhesion in an experimental model

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    Background: Postoperative intra-abdominal adhesion is associated with high morbidity and mortality. Smad7, a protein that occupies a strategic position in fibrogenesis, inhibits the transforming growth factor (TGF) β/Smad signalling pathway. In this study the therapeutic potential of exogenous Smad7 in preventing fibrogenesis in postoperative intra-abdominal adhesion was investigated. Methods: Intra-abdominal adhesion was induced in a rodent model by peritoneal abrasion. Smad7 was delivered into the peritoneal cavity by a non-viral ultrasound-microbubble-mediated naked gene transfection system. The effect of Smad7 transgene on adhesion formation was studied by measuring changes in TGF-β, fibrogenic factors, α-SMA and Smad2/3 activation in the anterior abdominal wall. Results: Four weeks after surgical abrasion, all rats developed significant peritoneal adhesion with enhanced TGF-β expression, increased levels of extracellular matrix components and activated myofibroblasts, accompanied by decreased Smad7 expression and increased Smad2/3 activation. In rats treated with the Smad7 transgene, the incidence and severity of peritoneal adhesion were significantly reduced, with biochemical downregulation of fibrogenic factors and inhibition of Smad2/3 activation. Serial quantitation using magnetic resonance imaging revealed a significant reduction in adhesion areas from day 14 onwards. Conclusion: Ultrasound-microbubble-mediated gene transfection provides timely targeted gene delivery for the treatment of postoperative peritoneal adhesions. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons Ltd.postprin

    Acclimation cost of common environmental stress to copepod tigriopus japonicus

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    Human ImpactsOral PresentationArthropogenic stress and climate change pose major challenges to survivorship of organisms. Acclimation to these changes often incurred energy costs to organisms and led to decrease in fitness. This presentation will make use of two studies, using copepod Tigriopus japonicus, to examine whether development of resistance to two common stressors (copper and thermal stress) can be acquired and whether fitness cost is involved. T. japonicus inhabits shallow supratidal tidepools that subject to extreme environmental conditions and has good tolerances to a wide ...postprin

    Risk-stratified seroprevalence of SARS coronavirus in children residing in a district with point-source outbreak compared to a low-risk area.

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    1. SARS coronavirus has low transmissibility at the community level. 2. Subclinical SARS coronavirus infection is rare in children.published_or_final_versio

    Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine

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    We randomized 115 children to trivalent inactivated influenza vaccine (TIV) or placebo. Over the following 9 months, TIV recipients had an increased risk of virologically-confirmed non-influenza infections (relative risk: 4.40; 95 confidence interval: 1.31-14.8). Being protected against influenza, TIV recipients may lack temporary non-specific immunity that protected against other respiratory viruses. © 2012 The Author.postprin

    Three-Dimensional Spectral-Domain Optical Coherence Tomography Data Analysis for Glaucoma Detection

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    Purpose: To develop a new three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) data analysis method using a machine learning technique based on variable-size super pixel segmentation that efficiently utilizes full 3D dataset to improve the discrimination between early glaucomatous and healthy eyes. Methods: 192 eyes of 96 subjects (44 healthy, 59 glaucoma suspect and 89 glaucomatous eyes) were scanned with SD-OCT. Each SD-OCT cube dataset was first converted into 2D feature map based on retinal nerve fiber layer (RNFL) segmentation and then divided into various number of super pixels. Unlike the conventional super pixel having a fixed number of points, this newly developed variable-size super pixel is defined as a cluster of homogeneous adjacent pixels with variable size, shape and number. Features of super pixel map were extracted and used as inputs to machine classifier (LogitBoost adaptive boosting) to automatically identify diseased eyes. For discriminating performance assessment, area under the curve (AUC) of the receiver operating characteristics of the machine classifier outputs were compared with the conventional circumpapillary RNFL (cpRNFL) thickness measurements. Results: The super pixel analysis showed statistically significantly higher AUC than the cpRNFL (0.855 vs. 0.707, respectively, p = 0.031, Jackknife test) when glaucoma suspects were discriminated from healthy, while no significant difference was found when confirmed glaucoma eyes were discriminated from healthy eyes. Conclusions: A novel 3D OCT analysis technique performed at least as well as the cpRNFL in glaucoma discrimination and even better at glaucoma suspect discrimination. This new method has the potential to improve early detection of glaucomatous damage. © 2013 Xu et al

    Gastrointestinal bleeding risk with rivaroxaban vs aspirin in atrial fibrillation: a multinational study

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    Purpose: Comparative gastrointestinal bleeding (GIB) risk between rivaroxaban and low‐dose aspirin is unknown in patients with atrial fibrillation (AF). This study investigated GIB risk with rivaroxaban vs aspirin among two separate AF cohorts in Hong Kong and the United Kingdom, using a common protocol approach. Methods: This was a population‐based cohort study using separate data from the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority (2010‐2018) and The Health Improvement Network (THIN) database in the United Kingdom (2011‐2017). Patients with AF newly prescribed aspirin or rivaroxaban were included. Cox proportional hazards regression was used to compare GIB risks for rivaroxaban vs aspirin, accounting for confounders using propensity score fine stratification approach. Results: In CDARS, 29 213 patients were included; n = 1052 (rivaroxaban), n = 28 161 (aspirin). Crude GIB event rates per 100 patient‐years in CDARS were 3.0 (aspirin) and 2.6 (rivaroxaban). No difference in GIB risk was observed between rivaroxaban and aspirin overall (HR = 1.04, 95%CI = 0.76‐1.42), and in dose‐stratified analyses (HR = 1.21, 95%CI = 0.84‐1.74 [20 mg/day]; HR = 0.80, 95%CI = 0.44‐1.45 [≤15 mg/day]). In THIN, 11 549 patients were included, n = 3496 (rivaroxaban) and n = 8053 (aspirin). Crude GIB event rates were 1.3 (aspirin) and 2.4 (rivaroxaban) per 100 patient‐years. No difference in GIB risk was observed between rivaroxaban and aspirin overall (HR = 1.40, 95%CI = 1.00‐1.98) and low‐dose rivaroxaban (≤15 mg/day) (HR = 1.00, 95%CI = 0.56‐1.30), but increased GIB risk was observed for rivaroxaban 20 mg/day vs aspirin (HR = 1.57, 95%CI = 1.08‐2.29). Conclusion: In patients with AF, GIB risk was comparable between aspirin and rivaroxaban ≤15 mg/day. GIB risk for rivaroxaban 20 mg/day vs aspirin remains uncertain and warrants further investigation

    Role of polymorphisms of the inflammatory response genes and DC-SIGNR in genetic susceptibility to SARS and other infections.

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    Research Fund for the Control of Infectious Diseases: Research Dissemination Reports (Series 2)1. A genetic risk-association study involving more than 1200 subjects showed individuals homozygous for L-SIGN tandem repeats are less susceptible to SARS infection. 2. This was supported by in vitro binding studies that demonstrated homozygous L-SIGN, compared to heterozygous, had higher binding capacity for SARS coronavirus (SARS-CoV), with higher proteasome-dependent viral degradation. In contrast, homozygous L-SIGN demonstrated lower binding capacity for HIV1-gp120.3. Genetic-association studies for single nucleotide polymorphisms of the inflammatory response genes, namely TNF-alpha, INF-alpha, INF-beta, INF-gamma, IL1-alpha, IL1-beta, IL-4, IL-6 and iNOS, failed to show a significant association with SARS clinical outcomes or susceptibility.published_or_final_versio
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