Study of PMN-PT single crystals for resonator applications

2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Magnetic and luminescent properties of multifunctional GdF₃: Eu³⁺ nanoparticles

Author name used in this publication: H. L. W. Chan2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Influenza B viruses in swine: virus tropism in swine respiratory organ explant cultures

Poster Session: Virology and Viral ReceptorsBackground: Swine has been considered an animal reservoir of pandemic influenza A virus (IAV), for example, the 2009 H1N1 pandemic virus, swine is acting as a “mixing vessel” for the reassortment of swine, human and avian IAVs. Certain influenza B virus (IBV) strains were also found to be readily infecting piglets as early as in 1969. However, tissue tropism of IBV in swine is understudied, at least in 2000s, mainly due to the misconception that IBV causes milder disease than IAV. IBV has in fact circulated in many parts of the world causing regular seasonal epidemics in humans with mortality rates sometimes higher than that in IAV seasons. Here, our research group hypothesizes that swine could be a neglected host of IBV, apart from human and seal, due to the previous infectivity of IBV in this animal, as well as the fact that swine has close contact with human and possesses a similar sialic acid (influenza virus receptor) distribution profile as the human respiratory tract. We aim to examine the characteristics of IBV tissue tropism using swine tracheal and lung explant models, and risk assess swine susceptibility to a panel of IBV strains from both Yamagata and Victoria lineages of different years. Materials and Methods: The tracheal and lung explants were prepared from fresh swine respiratory organs from approximately 6-month-old pigs, and cultured with maximal similarity to the in vivo conditions. A panel of IBV strains, from both Yamagata and Victoria lineages and from different years, were used to infect the tissue explants at 37oC or 39oC according to the original physiological temperature of the tissue. The virus replication efficiencies were evaluated through viral titration and immunohistochemistry of the collected supernatant and formalin-fixed tissue explants respectively at 1, 24, 48 and 72 h postinfection. Seasonal IAVs (H1N1 - A/OK/447/08 and H3N2 - A/OK/370/05) were used as controls. Results: Most of the tested IBVs showed productive replication in the swine lung explants. Swine tracheal explants, on the other hand, supported the replication of limited IBV strains. Most of these IBVs belong to the Victoria lineage, which spread across the years from 2005 to 2011. IBVs that could replicate in swine lung explants reached their maxima at 48 hpi or sometimes later. This is comparatively slower than the replication rates of seasonal IAVs (H1N1 & H3N2) used in the study, which usually showed significant increase at 24 hpi with still increasing virus yields at 48 hpi in some cases. However, the overall increase in titres between the IBVs and seasonal IAVs were similar. In swine tracheal explants, both IBVs and seasonal IAVs showed limited replications with similar trends of having maxima being reached at 24 hpi. Conclusions: The successful replication of IBVs in swine explants cultures indicates the possible susceptibility of swine to IBV and provides the essential basis for further investigation on the likelihood for swine to be an animal reservoir of the virus, as well as the threat it may pose to humans. Continuous studies on the replication kinetics of a greater number of IBVs in swine explant cultures across a wider range of years, countries and lineages will probably be our future target.published_or_final_versio

A multiscale error diffusion technique for digital halftoning with dot-overlap compensation

Author name used in this publication: C. K. LiVersion of RecordPublishe

Stimulus-specific adaptation at the synapse level in vitro

published_or_final_versio

Evaluation of the human adaptation of influenza A/H7N9 virus in PB2 protein using human and swine respiratory tract explant cultures

Novel avian H7N9 virus emerged in China in 2013 resulting in a case fatality rate of around 39% and continues to pose zoonotic and pandemic risk. Amino acid substitutions in PB2 protein were shown to influence the pathogenicity and transmissibility of H7N9 following experimental infection of ferrets and mice. In this study, we evaluated the role of amino acid substitution PB2-627K or compensatory changes at PB2-591K and PB2-701N, on the tropism and replication competence of H7N9 viruses for human and swine respiratory tracts using ex vivo organ explant cultures. Recombinant viruses of A/Shanghai/2/2013 (rgH7N9) and its mutants with PB2-K627E, PB2-K627E + Q591K and PB2-K627E + D701N were generated by plasmid-based reverse genetics. PB2-E627K was essential for efficient replication of rgH7N9 in ex vivo cultures of human and swine respiratory tracts. Mutant rgPB2-K627E + D701N replicated better than rgPB2-K627E in human lung but not as well as rgH7N9 virus. The rgPB2-K627E mutant failed to replicate in human type I-like pneumocytes (ATI) and peripheral blood monocyte-derived macrophages (PMϕ) at 37 °C while the compensatory mutant rgPB2-K627E + Q591K and rgPB2-K627E + D701N had partly restored replication competence in PMϕ. Our results demonstrate that PB2-E627K was important for efficient replication of influenza H7N9 in both human and swine respiratory tracts.published_or_final_versio

Worsened arterial stiffness in high-risk cardiovascular patients with high habitual carbohydrate intake: a cross-sectional vascular function study

BACKGROUND: Previous studies suggested that high dietary carbohydrate intake is associated with increased cardiovascular risk through raised triglyceride and decreased high-density lipoprotein-cholesterol levels. However, the relation between carbohydrate intake and arterial stiffness has not been established. The purpose of this study was to examine this relation among high-risk cardiovascular patients. METHODS: We studied the relation between dietary macronutrient intake and arterial stiffness in 364 patients with documented cardiovascular diseases or risk equivalent (coronary artery diseases 62%, ischemic stroke 13%, diabetes mellitus 55%) and in 93 age-and-sex matched control subjects. Dietary macronutrient intake was assessed using a validated food-frequency questionnaire (FFQ) for Chinese. Heart-ankle pulse wave velocity (PWV) was measured non-invasively with a Vascular Profiling System (VP2000, Colin Corp. USA). A dietary pattern with >/=60% total energy intake derived from carbohydrates was defined as a high-carbohydrate diet according to the Dietary Reference Intakes (DRI) for Chinese. RESULTS: Subjects who consumed a high-carbohydrate diet had significantly higher mean PWV than those who did not consume a high-carbohydrate diet (P = 0.039). After adjustment for potential confounders, high-carbohydrate diet was associated with significantly increased PWV [B = 73.50 (10.81 to 136.19), P = 0.022]. However, there was no significant association between high-carbohydrate diet and PWV in controls (P = 0.634). CONCLUSIONS: High-carbohydrate diet is associated with increased arterial stiffness in patients with established cardiovascular disease or risk equivalent.published_or_final_versio

A novel osmosis membrane bioreactor-membrane distillation hybrid system for wastewater treatment and reuse

© 2016 . A novel approach was designed to simultaneously enhance nutrient removal and reduce membrane fouling for wastewater treatment using an attached growth biofilm (AGB) integrated with an osmosis membrane bioreactor (OsMBR) system for the first time. In this study, a highly charged organic compound (HEDTA3-) was employed as a novel draw solution in the AGB-OsMBR system to obtain a low reverse salt flux, maintain a healthy environment for the microorganisms. The AGB-OsMBR system achieved a stable water flux of 3.62 L/m2 h, high nutrient removal of 99% and less fouling during a 60-day operation. Furthermore, the high salinity of diluted draw solution could be effectively recovered by membrane distillation (MD) process with salt rejection of 99.7%. The diluted draw solution was re-concentrated to its initial status (56.1 mS/cm) at recovery of 9.8% after 6 h. The work demonstrated that novel multi-barrier systems could produce high quality potable water from impaired streams