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In previous works, the authors showed that nylon nanofibers in the form of a random mat (nanomat) obtained by electrospinning can be used in bonded joints, where they may also work as an adhesive carrier. In those works, the setup of the bonding procedure started from a low-viscosity epoxy resin for hand layup in order to facilitate wetting of the nanomat, then a medium viscosity, two-component, unfilled epoxy adhesive was employed as an intermediate development step towards the addition of the nanomat to a high-viscosity, high strength, two-component epoxy adhesive system. The present work is therefore aimed at analyzing the performance of an epoxy adhesive for structural bonding, modified with the addition of a nylon nanomat generated by electrospinning. The adhesive is mixed and air bubbles are evacuated, then the nanomat is immersed in the adhesive, gently squeezed through two adjacent drums, counter-rotating at a given distance, in order to eliminate excess adhesive and to calibrate the wet nanomat thickness. The wet nanomat strip is finally placed between AA6082-T4 adherents and let to consolidate to obtain Double Cantilever Beam (DCB) bonded specimens. Fracture tests are performed and the mode-I fracture toughness with and without the nanomat is compared.

The improvement of the fracture toughness of adhesive joints is a key factor in many structural applications. The ability of nylon electrospun nanofibrous mat to act as an adhesive carrier and reinforcing web in adhesive bonding has been demonstrated by the Authors in previous works. It has been shown that the impregnation method developed and refined during the previous studies allow generating high-quality pre-preg nanomats out of a 2k unfilled epoxy resin. By applying this methodology, in the present work, rubbery nanofibrous mats have been adopted for the first time to reinforce and increase the fracture toughness of adhesive joints. Rubbery nanofibers were produced by electrospinning of nitrile butadiene rubber (NBR) and poly(e-caprolactone) (PCL). The addition of the semi-crystalline polymer (PCL) is exploited to maintain the nanofibrous morphology, which the rubber alone (NBR) would not be able to ensure due to its low glass transition temperature (Tg). The nanofibers thus obtained have been integrated into a two-component high strength epoxy resin for structural applications. S235 steel adherends for Double Cantilever Beam (DCB) tests have been manufactured and sandblasted to improve adhesion. An optimization of the sandblasting parameters (distance, pressure, angle and time) has been carried out evaluating the shear strength and the fracture surfaces on S235 steel Single Lap Joints (SLJ). Finally, DCB tests have been performed to compare the mode I fracture toughness with and without the rubbery electrospun nanomats.

The fracture toughness is a key parameter in the development of bonded joints for several structural applications. Adhesives are commonly toughened with fillers or modifying the resin chemical composition. Many studies also suggest that resin toughening could be achieved through electrospun polymer nanomat. In previous works, the Authors proved that nylon nanomats can be used as an adhesive carrier and reinforcing web for the adhesive layer. This allowed developing a laboratory route to produce high-quality prepregs of electrospun nylon carrier using medium viscosity, two-component, unfilled epoxy adhesive. By applying the same methodology, in the present work, electrospun nylon prepregs were produced using a high strength and high toughness 2k structural epoxy adhesive to toughen the joint. The wet nano-reinforced strips were placed between S235 steel sandblasted adherents and oven-cured to obtain Double Cantilever Beam (DCB) joints. DCB tests have been performed to compare the mode-I fracture toughness with and without the nanofibrous mat. Unlike previous works with medium-low toughness epoxies, this time the fracture toughness is reduced after the integration of an electrospun nano-reinforcement. From the Scanning Electron Microscope (SEM) images it seems that the nanomat hinders the ductile failure mechanism which instead develops in the neat resin.

The p210 BCR-ABL tyrosine kinase of chronic myeloid leukemia causes resistance to radio-induced apoptotic death by inhibiting the proapoptotic BAX gene

We developed a new cytomegalovirus (CMV) immunoglobulin M (IgM) immunoblot to detect CMV-specific IgM in human sera. The new test contains four viral proteins (vp150, vp82, vp65, and vp28) purified from viral particles and four recombinant proteins (rp150, rp130, rp52, and rp38) purified from Escherichia coli . These antigens were individually loaded onto nitrocellulose strips, and the strips were then used to detect CMV-specific IgM by using a μ-specific conjugate. The new assay was evaluated in parallel with one or two IgM enzyme-linked immunosorbent assays (ELISAs) to test 592 serum samples from different groups of latently or acutely infected individuals. The sensitivity of the new assay with respect to the consensus of two ELISAs was 100%, the specificity was 98.6%, the positive predictive value was 96.9%, and the negative predictive value was 100%. We also evaluated the new test by testing sera from pregnant women and transplant recipients with a known clinical history. Our results suggest that the new test combines high sensitivity with high specificity, characteristics that are mutually exclusive with the other commercially available tests. Furthermore, a statistically significant correlation was observed between the number of IgM-reactive bands and the elevated risk of transmission from CMV-infected pregnant women to their offspring.