518 research outputs found
Antiadenoviral effects of N-chlorotaurine in vitro confirmed by quantitative polymerase chain reaction methods
Eiichi Uchio1, Hirotoshi Inoue1, Kazuaki Kadonosono21Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, Japan; 2Department of Ophthalmology, Yokohama City University Medical Center, Yokohama, JapanPurpose: Adenoviral keratoconjunctivitis is recognized as one of the major pathogens of ophthalmological nosocomial infection worldwide. N-Chlorotaurine (Cl–HN–CH2–CH2–SO3H, NCT) is the N-chloro derivative of the amino acid taurine, which is an oxidant produced by human granulocytes and monocytes during inflammatory reactions. Using conventional viral plaque assay, it was previously shown that NCT causes inactivation of several human adenovirus (HAdV) serotypes. In this study, we evaluated the antiadenoviral effect of NCT by quantitative polymerase chain reaction (PCR) methods.Methods: A549 cells were used for viral cell culture, and HAdV serotypes 3, 4, 8, 19, and 37 were used. After calculating 50% cytotoxic concentration (CC50) of NCT by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) method, HAdV was cultured with NCT for 7 days, and extracted adenoviral DNA was quantitatively measured by real-time PCR.Results: A statistically significant (P < 0.05) dose-dependent inhibition was indicated for all serotypes except HAdV type 4 (HAdV4), which was maximally inhibited by only ~50%. Among the serotypes, NCT was particularly effective against HAdV8, HAdV19a, and HAdV37. The 50% effective concentration (EC50) obtained by real-time PCR of NCT ranged between 49 and 256 µM. EC50 of NCT against HAdV3 was slightly higher than that against serotypes of species D. The selective index (CC50/EC50) ranged between 41 and 60 except for HAdV4 (11.5).Conclusions: These results show that NCT has an antiviral effect against most serotypes of human HAdV inducing keratoconjunctivitis, indicating its possible therapeutic use.Keywords: adenovirus, N-chlorotaurine, epidemic keratoconjunctivitis, antiviral agen
Soft magnetic properties of ring shape bulk glassy Fe-Al-Ga-P-C-B-Si alloy prepared by copper mold casting
Magnetic spring characteristic of an oscillatory actuator with silicone rubber torsion springs for optical scanner applications
A compact electro-magnetic oscillatory actuator was proposed based on a pair of torsion springs for optical scanners operating at low oscillating frequencies, such as 50 Hz for a portable barcode scanner. Each torsion spring in the actuator is made of silicone rubber and is dually supported at both ends. A yoke is coupled with the driven coil to enhance the driving torque of the actuator. In this study, we analyzed the effect of the yoke on the resonant frequency of the actuator, as well as the torsion moment. We also experimentally determined the relationship between the resonant frequency and the magnetic gap of the yoke. Compared with the mechanical resonant frequency in the experiments, which was designed to be 50 Hz, the frequency was modified to 57.4 Hz, 54.7 Hz and 52.9 Hz when the gap between the yoke and the permanent magnet was 1.5 mm, 1.7 mm and 1.9 mm, respectively. The proposed actuator, which combines a yoke with flexible torsion springs, is potentially useful as a compact optical scanner, taking advantages of both low power consumption and high reliability.ArticleInt. J. Appl. Electromagn. Mech. 46(3):463-470(2014)journal articl
Bach1 gene ablation reduces steatohepatitis in mouse MCD diet model
Bach1 is a transcriptional repressor of heme oxygenase-1 (HO-1, a.k.a. HSP-32), which is an inducible enzyme and has anti-oxidation/anti-inflammatory properties shown in various models of organ injuries. Since oxidative stress plays a pivotal role in the pathogenesis of nonalcoholic steatohepatitis (NASH), HO-1 induction would be expected to prevent the development of NASH. In this study, we investigated the influence of Bach1 ablation in mice on the progression of NASH in methionine-choline deficient (MCD) diet model. Bach1 ablation resulted in significant induction of HO-1 mRNA and its activity in the liver. When fed MCD diet, Bach1−/− mice exhibited negligible hepatic steatosis compared to pronounced steatohepatitis in wild type mice with 6-fold increase in hepatic triglyceride content. Whereas feeding of MCD diet decreased mRNA expressions of peroxisome proliferator-activated receptor (PPAR) α and microsomal triglyceride transfer protein (MTP) in wild type mice, there were no change in Bach1−/− mice. In addition, hepatic concentration of malondialdehyde (MDA), a biomarker for oxidative stress as well as plasma alanine aminotransferase (ALT) was significantly lower in Bach1−/− mice. These findings suggest that Bach1 ablation exerts hepatoprotective effect against steatohepatitis presumably via HO-1 induction and may be a potential therapeutic target
New Function of Autophagy in C. jejuni Invasion
Campylobacter jejuni is a leading cause of food-borne disease worldwide. The pathogenicity of C. jejuni is closely associated with the internalization process in host epithelial cells, which is related to a host immune response. Autophagy indicates a key role in the innate immune system of the host to exclude invasive pathogens. Most bacteria are captured by autophagosomes and degraded by autophagosome-lysosome fusion in host cells. However, several pathogens, such as Salmonella and Shigella, avoid and/or escape autophagic degradation to establish infection. But autophagy involvement as a host immune response to C. jejuni infection has not been clarified. This study revealed autophagy association in C. jejuni infection. During infection, C. jejuni activated the Rho family small GTPase Rac1 signaling pathway, which modulates actin remodeling and promotes the internalization of this pathogen. In this study, we found the LC3 contribution to C. jejuni invasion signaling via the Rac1 signaling pathway. Interestingly, during C. jejuni invasion, LC3 was recruited to bacterial entry site depending on Rac1 GTPase activation just at the early step of the infection. C. jejuni infection induced LC3-II conversion, and autophagy induction facilitated C. jejuni internalization. Also, autophagy inhibition attenuated C. jejuni invasion step. Moreover, Rac1 recruited LC3 to the cellular membrane, activating the invasion of C. jejuni. Altogether, our findings provide insights into the new function of LC3 in bacterial invasion. We found the interaction between the Rho family small GTPase, Rac1, and autophagy-associated protein, LC3
A Novel High-Speed Electromagnetic Oscillatory Actuator With a Dual Mover for Optical Scanner Applications
In this paper, we propose a high-speed moving magnet-type oscillatory actuator in which a dual-mover structure is designed to reduce magnetic damping force. Both movers have independent resonant frequency, and the actuator is driven at the larger resonant frequency. The smaller mover serves as the optical scanning element and maintains large oscillation amplitude. The larger mover, with moving magnets, serves as the magnetic driving element and maintains relatively smaller amplitude because of the magnetic damping.ArticleIEEE TRANSACTIONS ON MAGNETICS. 50(11):8203504 (2014)journal articl
Directional linearly polarized terahertz emission from argon clusters irradiated by noncollinear double-pulse beams
It has been demonstrated that the interaction between argon clusters and intense femtosecond double laser pulses with appropriate intervals in time and space provides important properties for terahertz electromagnetic wave generation, namely, high forward directivity, power enhancement, and linear polarization with a variable direction. Irradiating argon clusters with double pulses (1 and 3 mJ, 40 fs, 810 nm) in 133-ps and 40-μm intervals results in terahertz wave emission in the forward direction that is 10 times greater than that for a single pulse. The polarization direction of terahertz electromagnetic waves can be varied by changing the relative focal positions of the first and second pulses
Magnetic Properties of Al-Si-MTM ( Magnetic Transition Metal) Melt Quenched Amorphous Ribbons
Al-Si-MTM( Magnetic Transition Metal) amorphous ribbons were prepared from the melts in order to investigate the magnetic properties. These samples have no magnetic moment, except for Al-Si-Mn amorphous alloys, showing no Curie-Weiss type temperature dependence of the magnetic susceptibility. Al-Si-Mn amorphous alloys exhibit a spin-glass like behavior such as a magnetic cooling effect. The very high electrical resistivity of Al-Si-Mn amorphous alloys is correlated to the magnetic and resonant scatterings. No microcrystalline precipitate was confirmed by electron microscope observation
Enhanced Hydrolyisis of Lignocellulosic Biomass Assisted by a Combination of Acidic Ionic Liquids and Microwave Heating
Lignocellulosic biomass was hydrolyzed by combining an acidic ionic liquid, 1-(1-butylsulfonic)-3-methylimidazolium hydrogen sulfate, and microwave heating, resulting in high glucose yields and short reaction times. This new approach achieved 40% glucose yield from bagasse within 12 min at 160°C; whereas, almost no glucose was yielded with a well-known method involving H2SO4 and conventional heating within 30 min at the same temperature. It was confirmed that the reaction temperature significantly affected glucose yield and reaction rate; whereas, the concentration of the acidic ionic liquid only affected the reaction rate. Three kinds of lignocellulosic biomass, including bagasse (herbaceous biomass), eucalyptus (hardwood), and Japanese cedar (softwood), were examined. Glucose yield was in the range of 30–40%, indicating that the present method effectively hydrolyzes various kinds of lignocellulosic biomasses
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