Glycosylation of Immunodominant Linear Epitopes in the Carboxy-Terminal Region of the Caprine Arthritis-Encephalitis Virus Surface Envelope Enhances Vaccine-Induced Type-Specific and Cross-Reactive Neutralizing Antibody Responses

This study evaluated type-specific and cross-reactive neutralizing antibodies induced by immunization with modified surface glycoproteins (SU) of the 63 isolate of caprine arthritis-encephalitis lentivirus (CAEV-63). Epitope mapping of sera from CAEV-infected goats localized immunodominant linear epitopes in the carboxy terminus of SU. Two modified SU (SU-M and SU-T) and wild-type CAEV-63 SU (SU-W) were produced in vaccinia virus and utilized to evaluate the effects of glycosylation or the deletion of immunodominant linear epitopes on neutralizing antibody responses induced by immunization. SU-M contained two N-linked glycosylation sites inserted into the target epitopes by R539S and E542N mutations. SU-T was truncated at 518A, upstream from the target epitopes, by introduction of termination codons at 519Y and 521Y. Six yearling Saanen goats were immunized subcutaneously with 30 μg of SU-W, SU-M, or SU-T in Quil A adjuvant and boosted at 3, 7, and 16 weeks. SU antibody titers determined by indirect enzyme-linked immunosorbent assay demonstrated anamnestic responses after each boost. Wild-type and modified SU-induced type-specific CAEV-63 neutralizing antibodies and cross-reactive neutralizing antibodies against CAEV-Co, a virus isolate closely related to CAEV-63, and CAEV-1g5, an isolate geographically distinct from CAEV-63, were determined. Immunization with SU-T resulted in altered recognition of SU linear epitopes and a 2.8- to 4.6-fold decrease in neutralizing antibody titers against CAEV-63, CAEV-Co, and CAEV-1g5 compared to titers of SU-W-immunized goats. In contrast, immunization with SU-M resulted in reduced recognition of glycosylated epitopes and a 2.4- to 2.7-fold increase in neutralizing antibody titers compared to titers of SU-W-immunized goats. Thus, the glycosylation of linear immunodominant nonneutralization epitopes, but not epitope deletion, is an effective strategy to enhance neutralizing antibody responses by immunization

High-performance carbon nanofiber reinforced epoxy-based nanocomposite adhesive materials modified with novel functionalization method and triblock copolymer

New high-performance epoxy-based nanocomposite adhesive materials were developed with the innovative use of nanomaterials to enhance the bond strength, especially at elevated temperatures. A tetraglycidyl diaminodiphenylmethane (TGDDM) based aerospace-grade epoxy adhesive (EA9396) with a high glass transition temperature and viscosity was combined with functionalized CNFs and a phase-separated poly(styrene)-poly(butadiene)-poly(methyl methacrylate) triblock copolymer (SBM). The ozone-treated CNFs (OZ-CNFs) were functionalized with polyethyleneimine dendrimer (PEI + OZ-CNFs), or a polyamine hardener (H + OZ-CNFs) and characterized using X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) to confirm the chemical reaction of the amine functional groups. Room temperature mechanical testing revealed the optimized nanocomposite adhesives containing SBM and CNFs functionalized with either PEI or hardener resulted in a 40% increase in lap shear strength (50 MPa) when compared to the unmodified epoxy (35.6 MPa). At the elevated temperature of 90 °C, a strength improvement of 35% and 38% (29.5 MPa and 30 MPa) was observed for the adhesives containing SBM and CNFs functionalized using PEI or hardener, respectively. SEM images showed that CNF functionalization provided a more uniform distribution in the adhesive and enhanced the SBM plastic deformation during crack propagation. The PEI and hardener functionalization also significantly reduced the level of CNF pull-out, which was believed to enhance the energy dissipation mechanisms responsible for the significant increase in the lap shear strength

Neutrality in Irish mediation, one concept, different meanings

The Mediation Act 2017 places mediation at the heart of the civil justice system in Ireland and protects some of the key principles of mediation. This article discusses neutrality, one of these principles. The article shows how neutrality is discussed by two sets of mediation stakeholders (clients and mediators). Using two data sets, the article demonstrates that both groups recognize the influence of neutrality on the mediation process. At the same time, the article shows that the manner in which both groups discuss neutrality is different

High-performance carbon nanofiber reinforced epoxy-based nanocomposite adhesive materials modified with novel functionalization method and triblock copolymer

New high-performance epoxy-based nanocomposite adhesive materials were developed with the innovative use of nanomaterials to enhance the bond strength, especially at elevated temperatures. A tetraglycidyl diaminodiphenylmethane (TGDDM) based aerospace-grade epoxy adhesive (EA9396) with a high glass transition temperature and viscosity was combined with functionalized CNFs and a phase-separated poly(styrene)-poly(butadiene)-poly(methyl methacrylate) triblock copolymer (SBM). The ozone-treated CNFs (OZ-CNFs) were functionalized with polyethyleneimine dendrimer (PEI + OZ-CNFs), or a polyamine hardener (H + OZ-CNFs) and characterized using X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) to confirm the chemical reaction of the amine functional groups. Room temperature mechanical testing revealed the optimized nanocomposite adhesives containing SBM and CNFs functionalized with either PEI or hardener resulted in a 40% increase in lap shear strength (50 MPa) when compared to the unmodified epoxy (35.6 MPa). At the elevated temperature of 90 °C, a strength improvement of 35% and 38% (29.5 MPa and 30 MPa) was observed for the adhesives containing SBM and CNFs functionalized using PEI or hardener, respectively. SEM images showed that CNF functionalization provided a more uniform distribution in the adhesive and enhanced the SBM plastic deformation during crack propagation. The PEI and hardener functionalization also significantly reduced the level of CNF pull-out, which was believed to enhance the energy dissipation mechanisms responsible for the significant increase in the lap shear strength

Influence of amino-functionalized carbon nanotubes and acrylic triblock copolymer on lap shear and butt joint strength of high viscosity epoxy at room and elevated temperatures

This study investigates the effectiveness of incorporating different amino-functionalized carbon nanotubes (CNTs) and acrylic triblock copolymer (BCP) into an aerospace-grade relatively high-viscosity epoxy (EA9396) resin to enhance the lap shear and tensile butt-joint strength at room and elevated temperatures (90 ◦C). To address the common issue of nanoparticle agglomeration in epoxy resin, which is exacerbated by its relatively high viscosity, a novel processing method was developed. This method involves ozone oxidation followed by functionalization with either polyethyleneimine (P + oz-CNTs) or a polyamine hardener (H + oz-CNTs). The functionalization not only ensures uniform dispersion of carbon nanotubes (CNTs) but also enhances their chemical reactivity with both the epoxy and block copolymer (BCP) matrix. The bonding performance of the epoxy, incorporating functionalized CNTs and BCP, was evaluated using single lap shear and tensile butt-joint tests. The results emphasize the substantial enhancement of both lap shear and butt-joint strength in the BCP-modified epoxy with the incorporation of functionalized CNTs (P + oz-CNTs and H + oz-CNTs), evident at both room temperature and 90 ◦C. At ambient conditions, the lap shear strength of the nanocomposite adhesives (P + oz-CNT + BCP EA9396 and H + oz-CNT + BCP/EA9396) exhibited significant improvements of 40 % and 48% respectively. At 90 ◦C, both formulations demonstrated a 20 % increase in lap shear strength. Furthermore, considerable advancements were observed in butt joint strength, with enhancements of 22 % (P + oz-CNT + BCP/EA9396) and 28 % (H + oz-CNT + BCP EA9396) at room temperature. Importantly, compared to the unmodified epoxy, the butt joint strength displayed even more remarkable improvements of 49 % (P + oz-CNT + BCP/EA9396) and 42 % (H + oz-CNT + BCP/EA9396) at 90 ◦C. The analysis of fracture studies showed that introducing amine functionalization resulted in a more consistent dispersion of CNTs and enhanced the ability of the BCP/EA9396 to undergo plastic deformation. The study further demonstrates that functionalization with PEI and amine hardener reduces CNT pull-out, which enhances energy dissipation mechanisms and increases lap shear and butt joint strengths