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Infection with hepatitis B virus (HBV) continues to be a major global cause of acute and chronic liver disease with high mortality. Herein, we examined both the anti-HBV and hepatoprotective activity of α-DDB–FNC. In human HBV-transfected liver cell line HepG2.2.15, α-DDB–FNC effectively suppressed the secretion of HBV antigens in a time and dose-dependent manner with 25.11% inhibition on HBeAg and 43.68% on HBsAg at 2.5 μM on day 9. Consistent with the HBV antigen reduction, α-DDB–FNC (2.5 μM) also reduced HBV DNA level by 77.74% extracellularly and 78.94% intracellularly on day 9. In the duck hepatitis B virus (DHBV) infected ducks, after α-DDB–FNC was given once daily for 10 days, the serum and liver DHBV DNA levels were reduced markedly with 96.81% and 97.21% at 10 mg kg −1 on day 10, respectively. In Con A-induced immunological liver-injury mice, α-DDB–FNC significantly inhibited the elevation of serum ALT, AST, TBiL and liver MDA, NO levels. Furthermore, significant improvement of the liver was observed after α-DDB–FNC treatment both in ducks and mice, as evaluated by the histopathological analysis. In conclusion, our results demonstrated that α-DDB–FNC possesses both antiviral activity against HBV and hepatoprotective effect to Con A-induced liver-injury mice.

Background HBV infection causes major public health problems worldwide. The clinical limitation of current antiviral drugs for HBV, such as lamivudine, is causing rapid emergence of drug-resistant viral strains during prolonged antiviral therapy. Therefore, new antiviral drugs are urgently needed to prevent or delay the selection of drug-resistant HBV mutants. A novel cytidine analogue, FNC (2′-deoxy-2′-β-fluoro-4′-azidocytidine), was recently shown to strongly inhibit human HBV and duck HBV (DHBV) replication in vitro and in vivo, respectively. The present study was designed to evaluate the in vitro antiviral activity of FNC against clinical wild-type and lamivudine-resistant HBV isolates in transiently transfected cells. Methods HBV DNA was extracted from serum samples collected both before lamivudine therapy and at the time of viral breakthrough and was amplified by PCR. The amplicon was cloned into a novel expression vector, pHY106, which can initiate the intracellular HBV replication cycle after cell transfection. Following transfection of the cloned amplicon into HepG2 cells, a drug susceptibility assay was performed. Quantitative real-time PCR was used for determining the amount of intracellular HBV DNA, and the effective concentration required to reduce HBV replication by 50% (EC50) was calculated. Results FNC inhibited the replication of both wild-type and lamivudine-resistant HBV clinical isolates in a dose-dependent manner, with mean ±sd EC50 values of 0.12 ±0.01 μM and 0.27 ±0.01 μM, respectively. Conclusions FNC is a potential antiviral agent against both wild-type and lamivudine-resistant HBV clinical isolates, and therefore deserves further evaluation for the treatment of HBV infection.

In 2008, Harn and Ren proposed an efficient identity-based RSA multisignatures scheme which it based on Shamir’s identity-based signature. In 2010, Yang et al. pointed out two methods that he presumed make the Harn-Ren scheme insecure. This documentation will prove that Yang et al.s first forgery attack was incorrect and the Harn-Ren scheme is still secure.

Vaccination is the preferred strategy for the prevention of influenza virus infection. Both H5N1 subunit and split vaccines have shown poor immunogenicity in clinical trials thus far. Therefore, it is urgent to develop more immunogenic and antigen-sparing H5N1 influenza vaccines as well as safe and effective adjuvants for humans, especially for immunocompromised people such as patients with diabetes mellitus. In this study, the protective effect of an MF59-adjuvanted inactivated whole-virion H5N1 vaccine was investigated in a type 1 diabetic mouse model. Mice (both healthy and diabetic) were immunized with a single dose of the inactivated vaccine, alone or adjuvanted with MF59 or Al(OH)(3). After four weeks, mice were challenged with a lethal dose of H5N1 virus. Antibody responses, survival rates, lung virus titers and body weight changes were tested. The results showed that addition of MF59 or Al(OH)(3) to the vaccine enhanced the antibody responses in both healthy mice and diabetic mice, but the MF59-adjuvanted groups showed higher antibody responses than the Al(OH)(3)-adjuvanted groups. The addition of MF59 or Al(OH)(3) to the vaccine led to a conversion of the immune response from a Th1-biased response to an enhanced mixed Th1/Th2 profile. The MF59-adjuvanted inactivated whole-virion H5N1 vaccine provided superior protection in type 1 diabetic mice to either the vaccine alone or the vaccine adjuvanted with Al(OH)(3).

To analyze reason of cracks formed on 42CrMo steel rollers after heat treatment, the material composition, heat treatment techniques, metallographical structure, crack morphologies were investigated. It was found that there are foreign matters in the cracks by using metallographic microscopes and scanning electron microscopes. Furthermore, there were a lot of pinholes and punctate foreign matters. The result from energy spectrum analysis showed that the oxygen content of foreign matters in cracks was remarkably higher than that of non-crack area. Combining the observation and analysis of polarizing microscope, it was concluded that the foreign matters are the mixture of FeO, Fe3O4 and Fe2O3, and the reason of cracks resulted form the foreign matters of ferriferous oxides formed the forging pucker during the forging process. After the mould cavity of the forging die had been improved, the cracks of the rollers disappeared.

Based on ABAQUS finite element analysis software, metallurgical composite bimetallic tube containing crack is analyzed and obtained the process of pipe rupture and the internal change of Mises stress and displacement at different crack depths and loading conditions. As the crack depth increases, the minimum values of the pipe Mises stress will increase and the maximum remain unchanged; as the load increases, the Mises stress and displacement values inside the pipe will increase with the equal speed. Maximum are all generated near the crack tip.

H9N2 avian influenza viruses have circulated widely in domestic poultry around the world, and their outbreaks have resulted in heavy morbidity and mortality. In addition, H9N2 avian influenza viruses were transmitted directly from birds to humans in Hong Kong and mainland China during 1998 and 2003, which prompted the public health authorities to seek protective strategies to control H9N2 influenza viruses. In this study, we attempted to develop a DIVA (differentiating infected and vaccinated animals) strategy for H9N2 avian influenza viruses. This strategy does not interfere with serological monitoring and allows effective control of H9N2 avian influenza. We generated a reassortant H9N1 influenza vaccine strain by reverse genetics and employed an enzyme-linked immunosorbent assay (ELISA) with a truncated N1 antigen expressed in E. coli to differentiate between vaccinated and naturally infected animals. Immunization of BALB/c mice with the inactivated reassortant H9N1 vaccine conferred protection against lethal challenge with H9N2 viruses. Meanwhile, the ELISA can be used to distinguish between vaccination and natural infection quickly and easily. Therefore, this study has opened up a new avenue for the control of H9N2 avian influenza.

Publisher Summary Vacuum cooling is a rapid cooling technique, which is achieved through boiling part of the moisture of the product under vacuum conditions. Any product can be vacuum cooled if it is porous and can afford to lose a proportion of water without an adverse effect on its quality. As a well-established commercial method to cool leafy vegetables, mushrooms and some delicate bakery products, it has also been employed to cool viscous and particulate food products, for example, sauces, meat slurries, or fruit concentrates, which usually are difficult to cool using traditional methods owing to their high viscosity and low thermal conductivity. Increased competitiveness together with safety concerns has led to a comprehensive research study of vacuum cooling of cooked meat joints and ready meals in the past few years, with results indicating that its potential is promising and benefits are large. However, vacuum cooling results in a high cooling loss, which decreases product yield and affects product quality. In general, as an innovative cooling technique, the benefits that vacuum cooling brings to the food industry are significant, in particular, in terms of reducing production cost and improving product quality and safety. As research, work continues on increasing the practical applications of vacuum cooling and improving the quality of the vacuum-cooled product.

Publisher Summary This chapter illustrates the various effects that power ultrasound generates when it is applied to the specific field of food freezing. Cavitation in the unfrozen liquid phase is one of the most significant phenomena provoked by the action of the acoustic energy. Cavitation results in the occurrence of microstreaming, which is able to enhance the heat and mass transfer accompanying the freezing process. Cavitation also benefits initiating the occurrence of nucleation and increasing the rate of nucleation as the gas bubbles produced can act as nucleating agents. Crystal fragmentation is another significant acoustic phenomenon, which can lead to crystal size reduction and, indeed, is one of the most important aspects that many freezing processes target. Resulting from these acoustic effects, power ultrasound has proved itself to be an effective method in assisting food freezing, and its benefits are wide-ranging. It can be utilized to induce nucleation and to control crystal size distribution in the frozen products during solidification of fluid food. If it is applied to the process of freezing fresh foodstuffs, it not only can increase the freezing rate but also can improve the quality of the frozen products. Application of power ultrasound can also benefit the prevention of incrustation on the freezing surface. The ability of power ultrasound in performing these functions is affected by a wide variety of parameters, such as the duration, intensity, or frequency of ultrasonic waves.

Vane type cam phasers have been widely used in internal combustion engines to vary valve timing to achieve purposes such as low emissions, greater torque, and higher horsepower. One of the primary concerns in using a vane phaser is its position holding ability when disturbances are present. Disturbances include cam torque oscillation, cam pulley speed fluctuation, oil pressure fluctuation, and engine acceleration or deceleration. Cam torque disturbance is the biggest contributor to phaser position error. This paper will first present the generic schematic of a variable cam phasing system and its challenges, followed by the characterization of the fluid dynamics of the vane phaser, with an emphasis on the effects of pressure, leakage, and oil aeration on the vane phaser fluid dynamics and its ability to reject cam torque disturbance. Finally, numerical evaluations of the vane phaser's ability to reject cam torque disturbance and sensitivity to various system parameters will be presented.

Nd-Fe-B powders were coated with CaF2 by three different chemical synthesis methods, named as A: One-step direct precipitation, B: One-step slow dropping, and C: Two-step process. The CaF2-coated Nd-Fe-B powders were hot-pressed and then hot-deformed to fabricate composite magnets. The microstructures, electrical resistivities, and magnetic properties of the Nd-Fe-B composite magnets obtained with different coating methods and parameters were investigated. The results showed that the thickness and continuity of CaF2 coating depended on the coating methods with different Ca(NO3)2 concentrations and coating time. When the Ca(NO3)2 concentration was 2 mol/l, the CaF2 coating synthesized by one-step direct precipitation was a loose and discontinuous film, while the CaF2 coating synthesized by one-step dropping for 30 min was a continuous and dense film, and its thickness reached to 410–450 nm. If the Ca(NO3)2 concentration was further increased to 5.5 mol/l, the thickness of CaF2 reached to 710–900 nm. The electrical resistivities of the composite magnets prepared by one-step slow dropping for 30 min with the Ca(NO3)2 concentrations of 2 and 5.5 mol/l were approximately 680 and 890 μΩ cm, which was a 195% and 287% increase, respectively, compared to that of the corresponding magnet prepared with uncoated Nd-Fe-B powders. The coercivities of the composite magnets decreased with increasing thickness of CaF2, while the remanence had only a slight reduction. The composite magnet fabricated by a two-step process achieved both higher maximum energy product ((BH)m = 47.2 MG Oe) and electrical resistivity (847 μΩ cm).

Sm 2 Fe 17 melt-spun powders were subjected to the nitriding process and followed by surfactant-assisted high-energy ball milling (HEBM). The microstructures, morphology and magnetic properties were also investigated by X-ray diffractometer, scanning electron microscope and vibrating sample magnetometer. The results showed that the coercivities of the nitrided Sm 2 Fe 17 powders were 1.64 kOe and 3.65 kOe when the nitriding temperatures were 350°C and 450°C, respectively. When the nitriding temperature was 350°C, there was a wasp-shaped hysteresis loop, due to the soft phase of iron, formed during the nitrogenation process. The subsequent surfactant-assisted HEBM can further improve the magnetic properties of the nitrided Sm 2 Fe 17 powders and a 3 h milling process increased the coercivity of the sample nitrided at 450°C reached a high value of 6.97 kOe.

Sm-Co hard nanoparticles have been synthesized by a modified mechanochemical processing. The phases, microstructure, particle sizes and magnetic properties of the synthesized Sm-Co nanoparticles have been investigated. The results showed that the precursors and milling times had great effects on the structure and magnetic properties of the synthesized Sm-Co nanoparticles. It is interesting to find that either Sm2Co7, SmCo5 or Sm2Co17 hard single phases can be obtained by manipulating the amount and ratio of starting materials of Sm2O3 and Co. After the mixture of Sm2O3, Co, Ca, and CaO powders were milled for 2–12 h, no Sm-Co based hard phases was formed, whereas the Sm-Co hard nanocrystallites were formed by a subsequent annealing at 650 °C for 1 h. The maximum coercivities of the synthesized Sm2Co7, SmCo5, and Sm2Co17 were 37.1, 35.5, and 10.8 kOe, respectively. Separated Sm2Co17 nanoparticles were obtained after washing the annealed powder with a solution of acetic acid aqueous solution. The washed Sm2Co17 particles were single crystals and had an average particle size of 81 nm.

Morphology, structure, and magnetic properties of the [001] textured Nd2Fe14B nanocrystalline flakes prepared by surfactant-assisted high energy ball milling (HEBM) and subsequent annealing were studied. These flakes have a thickness of 80–200 nm, a length of 0.5–10 μm, and an average grain size of 10–14 nm. The addition of some amount of Dy, Nd70Cu30 alloy, and an appropriate post annealing increased the coercivity iHc of the Nd2Fe14B flakes. iHc was 3.7, 4.3, and 5.7 kOe for the Nd15.5Fe78.5B6, Nd14Dy1.5Fe78.5B6 and 83.3 wt.% Nd14Dy1.5Fe78.5B6 + 16.7 wt.% Nd70Cu30 flakes prepared by HEBM for 5 h in heptane with 20 wt.% oleylamine, respectively. After annealing at 450 °C for 0.5 h, their iHc increased to 5.1, 6.2, and 7.0 kOe, respectively. Anisotropic magnetic behavior was found in all of the as-milled and annealed flakes. Both, the thickening of Nd-rich phase at grain boundaries via diffusion of Nd70Cu30 and the surface modification of the Nd2Fe14B flake could be the main reasons for the coercivity enh...

In this study, we discuss the effects of a type of surfactant (oleylamine, oleic acid, and trioctylamine) and hot pressing on the hard magnetic properties of crystallographically anisotropic SmCo5 nanoflakes prepared by surfactant-assisted high energy ball milling. The phase, microstructure, and magnetic properties of the hot-pressed SmCo5 were investigated by using x-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. The coercivities of the precursor flakes prepared using oleylamine, oleic acid, and trioctylamine were 14.9, 15.8, and 15 kOe, respectively. Hot-compacted SmCo5 magnets prepared from the nanoflakes milled with oleic acid had the lowest coercivity of 8.1 kOe. It is believed that even after repeated washing in an ultrasonic bath with different solvents, the remaining oleic acid in the SmCo5 nanoflakes led to oxidation of SmCo5 at the surface/interface of nanoflakes during the hot-pressing process. The compacted SmCo5 magnets prepared from the nanoflakes milled wi...

This work is focused on the evolution of structure, texture and magnetic properties in SmCo5 powders during high energy ball milling (HEBM) in heptane with and without oleic acid (OA). Single-crystal micron SmCo5 flakes were formed in the early stage of HEBM (0–0.5 h). However, HEBM of 1–2 h without OA led to the formation of a mixture of single-crystal microflakes and loosely agglomerated polycrystalline microparticles with the highest coercivity of 15.7 kOe. HEBM of 3–5 h without OA led to the formation of isotropic, more or less equiaxed SmCo5 particles with a size of 2–30 μm and a polycrystalline nanostructure due to the coalescence of flakes and particles. In the case of HEBM in heptane with 15 wt. % OA, prolonged milling (from 1 to 5 h) led first to the formation of SmCo5 single-crystal submicron flakes and later to submicron- and nanosize-nanocrystalline flakes with a [001]-out-of-plane texture. OA plays an essential role in the formation of anisotropic SmCo5 flakes via the impediment of cold welding and agglomeration of flakes. The highest coercivity of 17.7 kOe was obtained in a flake sample milled for 5 h with a thickness of 8–80 nm, an average grain size of 8 nm and an aspect ratio of 102–103.

BackgroundDeveloping vaccines for the prevention of human infection by H5N1 influenza viruses is an urgent task. DNA vaccines are a novel alternative to conventional vaccines and should contribute to the prophylaxis of emerging H5N1 virus. In this study, we assessed whether a single immunization with plasmid DNA expressing H5N1 hemagglutinin (HA) could provide early protection against lethal challenge in a mouse model.MethodsMice were immunized once with HA DNA at 3, 5, 7 days before a lethal challenge. The survival rate, virus titer in the lungs and change of body weight were assayed to evaluate the protective abilities of the vaccine. To test the humoral immune response induced by HA DNA, serum samples were collected through the eye canthus of mice on various days after immunization and examined for specific antibodies by ELISA and an HI assay. Splenocytes were isolated after the immunization to determine the antigen-specific T-cell response by the ELISPOT assay.ResultsChallenge experiments revealed that a single immunization of H5N1 virus HA DNA is effective in early protection against lethal homologous virus. Immunological analysis showed that an antigen-specific antibody and T-cell response could be elicited in mice shortly after the immunization. The protective abilities were correlated with the amount of injected DNA and the length of time after vaccination.ConclusionA single immunization of 100 μg H5 HA DNA vaccine combined with electroporation was able to provide early protection in mice against homologous virus infection.