Live poultry vaccines against highly pathogenic avian influenza viruses

The widespread circulation of highly pathogenic avian influenza viruses (HPAIVs) and their occasional transmission to humans creates a constant pandemic threat and leads to significant economic losses in the poultry industry. The development of an effective and safe vaccine for the broad protection of poultry from H5N1 HPAIVs remains an important goal. Prevention of the virus transmission between ducks and chickens is important for the efficient control of the spread of avian influenza. The oral administration of live vaccines corresponds to the natural route of infection that leads to virus replication in the intestinal epithelial cells that cause a well-balanced and broad immune response providing protection against the viruses of distant clades. The broad protection is the important advantage of live-attenuated influenza vaccines when compared to inactivated ones. Here, we give an overview of the latest approaches and results in the development of live poultry vaccine candidates against HPAIVs.The widespread circulation of highly pathogenic avian influenza viruses (HPAIVs) and their occasional transmission to humans creates a constant pandemic threat and leads to significant economic losses in the poultry industry. The development of an effective and safe vaccine for the broad protection of poultry from H5N1 HPAIVs remains an important goal. Prevention of the virus transmission between ducks and chickens is important for the efficient control of the spread of avian influenza. The oral administration of live vaccines corresponds to the natural route of infection that leads to virus replication in the intestinal epithelial cells that cause a well-balanced and broad immune response providing protection against the viruses of distant clades. The broad protection is the important advantage of live-attenuated influenza vaccines when compared to inactivated ones. Here, we give an overview of the latest approaches and results in the development of live poultry vaccine candidates against HPAIVs

Heat transport during drop impact onto a heated wall covered with an electrospun nanofiber mat: The influence of wall superheat, impact velocity, and mat thickness

Nanofiber surface coating is a promising method for the enhancement of heat transfer during spray cooling. In the present work, the drop dynamics as well as local and overall heat transfer during single drop impact onto a heated wall covered with a nanofiber mat are investigated to obtain insight into the mechanisms governing the heat transport enhancement. The influence of wall superheat, drop impact velocity, and mat thickness on the hydrodynamics and heat transfer from the heated wall to the fluid is studied. Polyacrylonitrile (PAN) was electrospun on a heater surface to manufacture the nanofiber mat coatings. The experiments were conducted inside a temperature-controlled test cell with a pure vapor atmosphere maintained with refrigerant FC-72. The temperature field at the solid-fluid interface was observed with a high-speed infrared camera, and the heat flux field was derived by solving a three-dimensional transient heat conduction equation within the substrate. The presence of the nanofiber mat on the heater surface suppresses the drop receding phase due to the pinning of the contact line at the end of the spreading phase. Two different scenarios are observed depending on the wall superheat and drop impact velocity: scenario (I), in which the liquid drop penetrated the porous nanofiber mat and touches the heater surface; and scenario (II) in which the vapor produced inside the pores of the nanofiber mat prevented the liquid drop from touching the heater surface. At a certain point in time after impact, the energy transferred from the nanofiber-coated surface to the liquid exceeds that of the uncovered heater owing to the larger drop footprint. If scenario (I) occurs, then the total transported heat increases significantly compared with the drop impact on a bare substrate.Comment: 19 pages, 19 figure

Dual role of the p38 MAPK/cPLA2MAPK/cPLA_2 pathway in the regulation of platelet apoptosis induced by ABT-737 and strong platelet agonists

p38 Mitogen-activated protein (MAP) kinase is involved in the apoptosis of nucleated cells. Although platelets are anucleated cells, apoptotic proteins have been shown to regulate platelet lifespan. However, the involvement of p38 MAP kinase in platelet apoptosis is not yet clearly defined. Therefore, we investigated the role of p38 MAP kinase in apoptosis induced by a mimetic of BH3-only proteins, ABT-737, and in apoptosis-like events induced by such strong platelet agonists as thrombin in combination with convulxin (Thr/Cvx), both of which result in p38 MAP kinase phosphorylation and activation. A p38 inhibitor (SB202190) inhibited the apoptotic events induced by ABT-737 but did not influence those induced by Thr/Cvx. The inhibitor also reduced the phosphorylation of cytosolic phospholipase $A_2$ (cPLA2), an established p38 substrate, induced by ABT-737 or Thr/Cvx. ABT-737, but not Thr/Cvx, induced the caspase 3-dependent cleavage and inactivation of cPLA2. Thus, p38 MAPK promotes ABT-737-induced apoptosis by inhibiting the cPLA2/arachidonate pathway. We also show that arachidonic acid (AA) itself and in combination with Thr/Cvx or ABT-737 at low concentrations prevented apoptotic events, whereas at high concentrations it enhanced such events. Our data support the hypothesis that the p38 MAPK-triggered arachidonate pathway serves as a defense mechanism against apoptosis under physiological conditions

Nucleation chronology and electronic properties of In(As,Sb,P) graded composition quantum dots grown on InAs(100) substrate

We provide a detailed study of nucleation process, characterization, electronic and optical properties of graded composition quantum dots (GCQDs) grown from In-As-Sb-P composition liquid phase on an InAs(100) substrate in the Stranski-Krastanov growth mode. Our GCQDs exhibit diameters from 10 to 120 nm and heights from 2 to 20 nm with segregation profiles having a maximum Sb content of approximately 20% at the top and a maximum P content of approximately 15% at the bottom of the GCQDs so that hole confinement is expected in the upper parts of the GCQDs. Using an eight-band k · p model taking strain and built-in electrostatic potentials into account, we have computed the hole ground state energies and charge densities for a wide range of InAs1-x-ySbxPy GCQDs as close as possible to the systems observed in experiment. Finally, we have obtained an absorption spectrum for an ensemble of GCQDs by combining data from both experiment and theory. Excellent agreement between measured and simulated absorption spectra indicates that such GCQDs can be grown following a theory-guided design for application in specific devices

Nucleation chronology and electronic properties of In(As,Sb,P) graded composition quantum dots grown on InAs(100) substrate

We provide a detailed study of nucleation process, characterization, electronic and optical properties of graded composition quantum dots (GCQDs) grown from In-As-Sb-P composition liquid phase on an InAs(100) substrate in the Stranski-Krastanov growth mode. Our GCQDs exhibit diameters from 10 to 120 nm and heights from 2 to 20 nm with segregation profiles having a maximum Sb content of approximately 20% at the top and a maximum P content of approximately 15% at the bottom of the GCQDs so that hole confinement is expected in the upper parts of the GCQDs. Using an eight-band k · p model taking strain and built-in electrostatic potentials into account, we have computed the hole ground state energies and charge densities for a wide range of InAs1-x-ySbxPy GCQDs as close as possible to the systems observed in experiment. Finally, we have obtained an absorption spectrum for an ensemble of GCQDs by combining data from both experiment and theory. Excellent agreement between measured and simulated absorption spectra indicates that such GCQDs can be grown following a theory-guided design for application in specific devices

Monoclonal antibodies differentially affect the interaction between the hemagglutinin of H9 influenza virus escape mutants and sialic receptors

AbstractTo determine the receptor binding properties of various H9 influenza virus escape mutants in the presence and absence of antibody, sialyloligosaccharides conjugated with biotinylated polyacrylamide were used. A mutant virus with a L226Q substitution showed an increased affinity for the Neu5Acα2-3Galβ1-4Glc. Several escape mutants viruses carrying the mutation N193D bound to Neu5Acα2-6Galβ1-4GlcNAc considerably stronger than to Neu5Acα2-6Galβ1-4Glc. Several monoclonal antibodies unable to neutralize the escape mutants preserved the ability to bind to the hemagglutinin as revealed by enzyme-linked immunosorbent assay. In each case, the bound monoclonal antibodies did not prevent the binding of the mutant HA to high affinity substrates and did not displace them from the virus binding sites. Together, these data suggest that amino acid changes selected by antibody pressure may be involved in the specificity of host-cell recognition by H9 hemagglutinin and in the ability of viruses with these mutations to escape the neutralizing effect of antibodies in a differential way, depending on the specificity of the host cell receptor. It may be important in the natural evolution of the H9 subtype, a plausible candidate for the agent likely to cause a future pandemic

InAsSbP-based Quantum Dot Mid-Infrared Photodetectors: Fabrication, Properties and Applications

The mid-infrared photoconductive cells (PCC) made of n-InAs(100) crystals with InAsSbP quantum dots (QDs) on the PCC surface, as well as InAsSbP-based diode heterostructures with QDs on epilayer–substrate interface are reported. Both QDs-based semiconductor structures are considered as attractive devices for several mid-infrared applications. The liquid phase epitaxy, AFM, TEM and STM techniques are utilized for the growth of QDs and epitaxial cap layers and their characterization, respectively. Anoma-lous photovoltaic effect is detected in PCC with type-II QDs. The open-circuit voltage and short-circuit cur-rent are measured versus radiation power density of the He-Ne laser at λ 3.39, 1.15 and 0.63 μm wave-lengths. The formation of QDs leads to the increasing of the PCC’s sheet resistance up to one order and re-sults in red shift of the photoresponse spectrum. The QDs-based PCC’s voltage and current responsivity at room temperature are equal to 1.5 V/W and 82 mA/W, respectively, at zero bias and λ 3.39 μm. The main peak at 3.48 μm and additional peaks at 2.6 μm and 2.85 μm wavelengths revealed on QDs-based devices’ photoresponse and luminescence spectra allow to fabricate optical gas sensors, in particularly, for the me-thane, water vapor and carbon dioxide detection. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3535