Effects of Agaricus blazei Murill Extract on Immune Responses in Normal BALB/c Mice

[[abstract]]Agaricus blazei Murill (ABM) has shown particularly, strong results in treating and preventing cancer and has also traditionally been used as a food source in Brazil. However, the exact immune responses regarding the phagocytosis of macrophage and, the activity of natural killer (NK) cells in normal mice after exposure to ABM extract was unclear. The goal of this study, was to investigate whether or not ABM extract can promote immune responses in normal BALB/c mice. BALB/c mice were treated with different doses of ABM extract for different time periods. The results indicated that ABM extract significantly promoted the proliferation of splenocytes both in vitro and in vivo. ABM extract promoted the levels of interleukein-6 (IL-6) and, interferon-gamma (IFN-gamma) but reduced the levels of IL-4 in vitro and in vivo. The percentage of macrophages with phagocytosis after ABM extract treatment increased and these effects were of dose-dependent manners, both in vitro and in vivo. YAC-1 target cells were killed by NK cells from the mice after treatment with ABM extract at 3 and 6 mg/kg/day for up to 14 days at target cell ratios of 25:1 and 50:1. Taken together, these results show that ABM extract promoted immunomodulations in normal BALB/c mice in vitro and in vivo

Purification, crystallization and X-ray crystallographic analysis of a putative exopolyphosphatase from Zymomonas mobilis

Exopolyphosphatase (PPX) enzymes degrade inorganic polyphosphate (poly-P), which is essential for the survival of microbial cells in response to external stresses. In this study, a putative exopolyphosphatase from Zymomonas mobilis (ZmPPX) was crystallized. Crystals of the wild-type enzyme diffracted to 3.3 Å resolution and could not be optimized further. The truncation of 29 amino acids from the N-terminus resulted in crystals that diffracted to 1.8 Å resolution. The crystals belonged to space group C2, with unit-cell parameters a = 122.0, b = 47.1, c = 89.5 Å, α = γ = 90, β = 124.5°. An active-site mutant that crystallized in the same space group and with similar unit-cell parameters diffracted to 1.56 Å resolution. One molecule was identified per asymmetric unit. Analytical ultracentrifugation confirmed that ZmPPX forms a dimer in solution. It was confirmed that ZmPPX possesses exopolyphosphatase activity against a synthetic poly-P substrate.published_or_final_versio

Direct evidence to support the restriction of intramolecular rotation hypothesis for the mechanism of aggregation-induced emission: Temperature resolved terahertz spectra of tetraphenylethene

In contrast to the traditional fluorescent dyes that exhibit a decrease in fluorescence upon aggregation, Aggregation-Induced Emission (AIE) molecules are a family of fluorophors which exhibit increased fluorescence upon aggregation. Consequently, AIE molecules represent an interesting new material with potential applications in fluorescent chemo/biosensors, light emitting devices and medical diagnostics. Numerous mechanisms have been proposed to explain this phenomenon, including isomerisation, and restriction of intramolecular rotations (RIR). However, there has not been any direct experimental evidence to support either one of these hypotheses. Here we use terahertz time-domain-spectroscopy (THz-TDS) and solid-state computational simulations of an AIE molecule to link the increase in intensity of intramolecular rotation and rocking modes to the measured fluorescence and reveal direct evidence supporting the RIR hypothesis. This is the first time that terahertz spectroscopy has been used to directly probe such molecular motions in AIE materials and in doing so we have found conclusive evidence to fully explain the AIE mechanism.This is the accepted version of an article first published in Materials Horizons. The version of record is available from the Royal Society of Chemistry at http://xlink.rsc.org/?DOI=c3mh00078

Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators

Topological crystalline insulators in IV-VI compounds host novel topological surface states consisting of multi-valley massless Dirac fermions at low energy. Here we show that strain generically acts as an effective gauge field on these Dirac fermions and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict the realization of this phenomenon in IV-VI semiconductor heterostructures, due to a naturally occurring misfit dislocation array at the interface that produces a periodically varying strain field. Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of the Dirac point, and coexist with a network of snake states at higher energy. We propose that the high density of states of this flat band gives rise to interface superconductivity observed in IV-VI semiconductor multilayers at unusually high temperatures, with non-BCS behavior. Our work demonstrates a new route to altering macroscopic electronic properties to achieve a partially flat band, and paves the way for realizing novel correlated states of matter.Comment: Accepted by Nature Physic

Hazard Analysis of Critical Control Points Assessment as a Tool to Respond to Emerging Infectious Disease Outbreaks

Highly pathogenic avian influenza virus (HPAI) strain H5N1 has had direct and indirect economic impacts arising from direct mortality and control programmes in over 50 countries reporting poultry outbreaks. HPAI H5N1 is now reported as the most widespread and expensive zoonotic disease recorded and continues to pose a global health threat. The aim of this research was to assess the potential of utilising Hazard Analysis of Critical Control Points (HACCP) assessments in providing a framework for a rapid response to emerging infectious disease outbreaks. This novel approach applies a scientific process, widely used in food production systems, to assess risks related to a specific emerging health threat within a known zoonotic disease hotspot. We conducted a HACCP assessment for HPAI viruses within Vietnam’s domestic poultry trade and relate our findings to the existing literature. Our HACCP assessment identified poultry flock isolation, transportation, slaughter, preparation and consumption as critical control points for Vietnam’s domestic poultry trade. Introduction of the preventative measures highlighted through this HACCP evaluation would reduce the risks posed by HPAI viruses and pressure on the national economy. We conclude that this HACCP assessment provides compelling evidence for the future potential that HACCP analyses could play in initiating a rapid response to emerging infectious diseases

Hybrid Equation/Agent-Based Model of Ischemia-Induced Hyperemia and Pressure Ulcer Formation Predicts Greater Propensity to Ulcerate in Subjects with Spinal Cord Injury

Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation. © 2013 Solovyev et al

鑑古識今：從課程發展策略的視角看課程改革

This article, by analysing the Mathematics curriculum development of Hong Kong in the period 1940s-1980s, aimed to learn from the past. It stressed that the education bureau had adopted various effective strategies in curriculum development, though it centrally-controlled the development. The education bureau had adopted incremental model through consideration of context, implemented curriculum orderly and used techniques of absorptive politics to introduce strengths and ideas from grassroots and to interact with teacher associations. Inquiring from historical development, this article raised five dimensions of thought for curriculum development: strategies need to consider trends of recent change, considering the context of society, provision of space and flexibility when using top-down approach, accepting voice from grassroots, and investigating the possibility of devolution of power when responding to requests. 鑑古識今，本文從分析1940 - 1980期間香港小學數學課程的發展，指出香港過往的數學課程發展雖然由桝育 部門作「中央監控」，但亦採取「漸進發展」的課程發展模式，因應時勢，有序地推行數學課程改革，而且 以吸納政治的技巧，引入民間力量和聲音，著重與桝師團體的互動。從歷史發展的探索，本文提出五方面的 思考：課程發展策略要因應時勢發展，需因地制宜，雖由上而下但仍給予自主空間和彈性，容納民間聲音， 以及探討權力下放的可行性以回應時代需求