Predicting Antigenic Variants of Influenza A/H3N2 Viruses

Models based on amino acid changes in influenza hemagglutinin protein were compared to predict antigenic variants of influenza A/H3N2 viruses

Process development of chromatography-based purification on pandemic influenza virus-like particle based vaccines

Since 2013, the H7N9 avian influenza virus is considered a threat to global public health. The development of the H7N9 avian influenza vaccine is one of the most effective strategies to prevent influenza pandemics. Virus-like particles (VLPs) influenza vaccines is non-infectious viral structural proteins. Not only to retain the ability to produce neutralizing antibodies against to viral surface protein, but also safer than the conventional inactivated vaccines. In our previous study, we successfully expressed three structural proteins, hemagglutinin (HA), neuraminidase (NA) and matrix (M1) from influenza A / Taiwan / 1/2013 (H7N9) of the VLP in insect cells. In this study, we present a downstream purification method for the VLP platform. The purification process involves microfiltration, chromatography (using ion exchange, affinity and gel filtration combinations), concentration, diafiltration and sterile filtration steps. In this study, 600 ml of the harvest from the baculovirus expression system was used. The characteristics of VLP volume were examined by HA assay, SDS-PAGE and negative staining transmission electron microscopy (TEM). The overall recovery of HA protein was approximately 38%. In the evaluation of immunized mouse, such virus particles have been shown the HI titer \u3e256. This study demonstrated the chromatographic-based purification process can provide an effective VLP vaccine production for the preparation of the H7N9 influenza pandemic

Stability evaluation of inactivated influenza H7N9 vaccines derived from adhesion and suspension MDCK cells

In recent years, cell-based manufacturing processes for influenza vaccine production has gained a great interest over the egg-based process. We have adapted MDCK cells to grow in chemical-defined medium and found this newly suspension MDCK cell line (sMDCK cells) is very suitable for the production of influenza virus. However, the property of purified antigens from sMDCK cells remains unclear. In this study, a stability program of influenza H7N9 vaccine (NIBRG268 vaccine strain) produced by sMDCK cells was investigated, and the data were compared with the vaccine derived from adhesion MDCK (aMDCK) cells in serum-free medium. The H7N9 bulks (with different storage time) derived from sMDCK and aMDCK cells were stored at 2-8°C for some times, and a number of parameters were used to monitor the H7N9 vaccine antigen stability was evaluated at different periods (1, 2, 3 and 6 months). The monitoring parameters are including virus structure, HA titer, HA content, total protein level, antigenicity, and immunogenicity. The sMDCK-derived H7N9 bulk showed similar virus structure to that aMDCK-derived H7N9 bulk, and there was no obvious change after further 6 months of storage. Furthermore, HA titer, HA content and total protein level of sMDCK- and aMDCK-derived H7N9 bulks were stable after 6 months of storage. sMDCK- and aMDCK-derived H7N9 bulks displayed similar antigenicity detected by hemagglutination inhibition (HI) test using standard serum. Finally, the results of HI and neutralization tests showed that sMDCK- and aMDCK-derived H7N9 vaccines were similar in immunogenicity in BALB/c mice vaccinated with 0.2 μg of H7N9 vaccine with an adjuvant of aluminum hydroxide. These results indicate that sMDCK-derived H7N9 bulk has good stability data similar to the aMDCK-derived H7N9 bulk. Thus, the newly developed suspension MDCK cells show a great market potential over the traditional vaccine manufacturing methods

Insulin-Mimetic Action of Rhoifolin and Cosmosiin Isolated from Citrus grandis (L.) Osbeck Leaves: Enhanced Adiponectin Secretion and Insulin Receptor Phosphorylation in 3T3-L1 Cells

Citrus grandis (L.) Osbeck (red wendun) leaves have been used in traditional Chinese medicine to treat several illnesses including diabetes. However, there is no scientific evidence supporting these actions and its active compounds. Two flavone glycosides, rhoifolin and cosmosiin were isolated for the first time from red wendun leaves and, identified these leaves are rich source for rhoifolin (1.1%, w/w). In differentiated 3T3-L1 adipocytes, rhoifolin and cosmosiin showed dose-dependent response in concentration range of o.oo1–5 μM and 1–20 μM, respectively, in biological studies beneficial to diabetes. Particularly, rhoifolin and cosmosiin at 0.5 and 20 μM, respectively showed nearly similar response to that 10 nM of insulin, on adiponectin secretion level. Furthermore, 5 μM of rhoifolin and 20 μM of cosmosiin showed equal potential with 10 nM of insulin to increase the phosphorylation of insulin receptor-β, in addition to their positive effect on GLUT4 translocation. These findings indicate that rhoifolin and cosmosiin from red wendun leaves may be beneficial for diabetic complications through their enhanced adiponectin secretion, tyrosine phosphorylation of insulin receptor-β and GLUT4 translocation

Real-time visualization of clustering and intracellular transport of gold nanoparticles by correlative imaging.

Mechanistic understanding of the endocytosis and intracellular trafficking of nanoparticles is essential for designing smart theranostic carriers. Physico-chemical properties, including size, clustering and surface chemistry of nanoparticles regulate their cellular uptake and transport. Significantly, even single nanoparticles could cluster intracellularly, yet their clustering state and subsequent trafficking are not well understood. Here, we used DNA-decorated gold (fPlas-gold) nanoparticles as a dually emissive fluorescent and plasmonic probe to examine their clustering states and intracellular transport. Evidence from correlative fluorescence and plasmonic imaging shows that endocytosis of fPlas-gold follows multiple pathways. In the early stages of endocytosis, fPlas-gold nanoparticles appear mostly as single particles and they cluster during the vesicular transport and maturation. The speed of encapsulated fPlas-gold transport was critically dependent on the size of clusters but not on the types of organelle such as endosomes and lysosomes. Our results provide key strategies for engineering theranostic nanocarriers for efficient health management

ATIVS: analytical tool for influenza virus surveillance

The WHO Global Influenza Surveillance Network has routinely performed genetic and antigenic analyses of human influenza viruses to monitor influenza activity. Although these analyses provide supporting data for the selection of vaccine strains, it seems desirable to have user-friendly tools to visualize the antigenic evolution of influenza viruses for the purpose of surveillance. To meet this need, we have developed a web server, ATIVS (Analytical Tool for Influenza Virus Surveillance), for analyzing serological data of all influenza viruses and hemagglutinin sequence data of human influenza A/H3N2 viruses so as to generate antigenic maps for influenza surveillance and vaccine strain selection. Functionalities are described and examples are provided to illustrate its usefulness and performance. The ATIVS web server is available at http://influenza.nhri.org.tw/ATIVS/

FuelCell2009-85133 THE APPLICATION OF A PORTABLE DMFCS STACK WITH FRACTAL CURRENT COLLECTORS USING HILBERT GEOMETRY FOR A CHARGER SYSTEM

ABSTRACT The study develops a portable charger platform that contains a direct methanol fuel cell (DMFC) consisting of a set of planar DMFCs with current collectors, Fractal Hilbert Geometry and a power balance plant (BOP). The third order Hilbert geometry is used for the 35×35 mm2 current collectors. The system output design is set at 5V controlled by a power balance plant applied to 3C low power products. This paper discusses the Methanol feed rate, air flow rate, bipolar plate thickness and power balance plant layout for DMFC performance. To evaluate the reliability and efficiency of the DMFC power source, a data acquisition (DAQ) system connected to a real time monitor is used to assess the current and voltage output from the DMFC system while running different parameters. The results show the current of the charger system obtain 84 mA and 103 mA under 2V and 3V input voltage converters respectively. The transform efficiency for power balance plant is up to about 84% for 3V input voltage converter

Numerical Simulation of Epidemic Prevention and Ventilation Efficiency in Indoor Spaces with Partitions and an Air curtain

In this study, computational fluid dynamics (CFD) were used to simulate the effect of a partition and air curtain on the concentration of a pollution source in an indoor space with different ventilation configurations. First, in the partition simulation, the performances of six different ventilation configurations were compared. Based on the results obtained, air curtain simulations were then carried out. In this study, carbon dioxide was chosen as the tracer gas in all simulations, and the realizable k − ε turbulence model was selected. In the partition simulation, a front-and-back ventilation configuration with ventilation inlets/outlets near the side walls (in diagonal) showed the best performance. This configuration was adopted for the air curtain simulation so as to investigate the effect of different air inlet velocities and air curtain velocities. It was found that as the height of the partition increases, although it has a higher chance of blocking the Covid-19 virus, it lowers the ventilation efficiency, resulting in the increase of carbon dioxide concentration in the indoor space. When the partition was replaced with an air curtain, it was found that the higher the height of the air curtain, the lower the carbon dioxide concentration in the indoor space. Compared with the partition, the air curtain can reduce the carbon dioxide concentration by up to 74.6%, indicating that the introduction of the air curtain can have an improving effect on the ventilation in the indoor space

The effect of cigarette price increase on the cigarette consumption in Taiwan: evidence from the National Health Interview Surveys on cigarette consumption

BACKGROUND: This study uses cigarette price elasticity to evaluate the effect of a new excise tax increase on cigarette consumption and to investigate responses from various types of smokers. METHODS: Our sample consisted of current smokers between 17 and 69 years old interviewed during an annual face-to-face survey conducted by Taiwan National Health Research Institutes between 2000 to 2003. We used Ordinary Least Squares (OLS) procedure to estimate double logarithmic function of cigarette demand and cigarette price elasticity. RESULTS: In 2002, after Taiwan had enacted the new tax scheme, cigarette price elasticity in Taiwan was found to be -0.5274. The new tax scheme brought about an average annual 13.27 packs/person (10.5%) reduction in cigarette consumption. Using the cigarette price elasticity estimate from -0.309 in 2003, we calculated that if the Health and Welfare Tax were increased by another NT$ 3 per pack and cigarette producers shifted this increase to the consumers, cigarette consumption would be reduced by 2.47 packs/person (2.2%). The value of the estimated cigarette price elasticity is smaller than one, meaning that the tax will not only reduce cigarette consumption but it will also generate additional tax revenues. Male smokers who had no income or who smoked light cigarettes were found to be more responsive to changes in cigarette price. CONCLUSIONS: An additional tax added to the cost of cigarettes would bring about a reduction in cigarette consumption and increased tax revenues. It would also help reduce incidents smoking-related illnesses. The additional tax revenues generated by the tax increase could be used to offset the current financial deficiency of Taiwan's National Health Insurance program and provide better public services

Synthesis of High Crystalline Al-Doped ZnO Nanopowders from Al 2

High crystalline Al-doped ZnO (AZO) nanopowders were prepared by in-flight treatment of ZnO and Al2O3 in Radio-Frequency (RF) thermal plasma. Micron-sized (~1 μm) ZnO and Al2O3 powders were mixed at Al/Zn ratios of 3.3 and 6.7 at.% and then injected into the RF thermal plasma torch along the centerline at a feeding rate of 6.6 g/min. The RF thermal plasma torch system was operated at the plate power level of ~140 kVA to evaporate the mixture oxides and the resultant vapor species were condensed into solid particles by the high flow rate of quenching gas (~7000 slpm). The FE-SEM images of the as-treated powders showed that the multipod shaped and the whisker type nanoparticles were mainly synthesized. In addition, these nanocrystalline structures were confirmed as the single phase AZO nanopowders with the hexagonal wurtzite ZnO structure by the XRD patterns and FE-TEM results with the SAED image. However, the composition changes of 0.3 and 1.0 at.% were checked for the as-synthesized AZO nanopowders at Al/Zn ratios of 3.3 and 6.7 at.%, respectively, by the XRF data, which can require the adjustment of Al/Zn in the mixture precursors for the applications of high Al doping concentrations