384 research outputs found
Characterization of the rabbit neonatal Fc receptor (FcRn) and analyzing the immunophenotype of the transgenic rabbits that overexpresses FcRn
The neonatal Fc receptor (FcRn) regulates IgG and albumin homeostasis, mediates maternal IgG transport, takes an active role in phagocytosis, and delivers antigen for presentation. We have previously shown that overexpression of FcRn in transgenic mice significantly improves the humoral immune response. Because rabbits are an important source of polyclonal and monoclonal antibodies, adaptation of our FcRn overexpression technology in this species would bring significant advantages. We cloned the full length cDNA of the rabbit FcRn alpha-chain and found that it is similar to its orthologous analyzed so far. The rabbit FcRn - IgG contact residues are highly conserved, and based on this we predicted pH dependent interaction, which we confirmed by analyzing the pH dependent binding of FcRn to rabbit IgG using yolk sac lysates of rabbit fetuses by Western blot. Using immunohistochemistry, we detected strong FcRn staining in the endodermal cells of the rabbit yolk sac membrane, while the placental trophoblast cells and amnion showed no FcRn staining. Then, using BAC transgenesis we generated transgenic rabbits carrying and overexpressing a 110 kb rabbit genomic fragment encoding the FcRn. These transgenic rabbits - having one extra copy of the FcRn when hemizygous and two extra copies when homozygous - showed improved IgG protection and an augmented humoral immune response when immunized with a variety of different antigens. Our results in these transgenic rabbits demonstrate an increased immune response, similar to what we described in mice, indicating that FcRn overexpression brings significant advantages for the production of polyclonal and monoclonal antibodies
A Web Service Composition Method Based on OpenAPI Semantic Annotations
Automatic Web service composition is a research direction aimed to improve
the process of aggregating multiple Web services to create some new, specific
functionality. The use of semantics is required as the proper semantic model
with annotation standards is enabling the automation of reasoning required to
solve non-trivial cases. Most previous models are limited in describing service
parameters as concepts of a simple hierarchy.
Our proposed method is increasing the expressiveness at the parameter level,
using concept properties that define attributes expressed by name and type.
Concept properties are inherited. The paper also describes how parameters are
matched to create, in an automatic manner, valid compositions. Additionally,
the composition algorithm is practically used on descriptions of Web services
implemented by REST APIs expressed by OpenAPI specifications. Our proposal uses
knowledge models (ontologies) to enhance these OpenAPI constructs with JSON-LD
semantic annotations in order to obtain better compositions for involved
services. We also propose an adjusted composition algorithm that extends the
semantic knowledge defined by our model.Comment: International Conference on e-Business Engineering (ICEBE) 9 page
Raman phonon modes of zinc blende InxGa1-xN alloy epitaxial layers
Transverse-optical (TO) and longitudinal-optical (LO) phonons of zinc blende InxGa1-xN (0 less than or equal to x less than or equal to 0.31) layers are observed through first-order micro-Raman scattering experiments. The samples are grown by molecular-beam epitaxy on GaAs (001) substrates, and x-ray diffraction measurements are performed to determine the epilayer alloy composition. Both the TO and LO phonons exhibit a one-mode-type behavior, and their frequencies display a linear dependence on the composition. The Raman data reported here are used to predict the A(1) (TO) and E-1 (TO) phonon frequencies of the hexagonal InxGa1-xN alloy. (C) 1999 American Institute of Physics. [S0003-6951(99)01234-6].7581095109
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