Experimental Investigation of a Novel Formulation of a Cyanoacrylate-Based Adhesive for Self-Healing Concrete Technologies

The selection of an appropriate healing agent is critical to the success of vascular and mini-vascular networks. In self-healing concrete technology, commercially available cyanoacrylate (CA) adhesives have been shown to produce good strength recoveries; however, their rapid curing rate and short shelf-life make them unsuitable for site application. The aim of this study was to develop a modified cyanoacrylate (n-CA) with an extended shelf-life suitable for incorporation in a self-healing system. A series of n-CAs were formed from a commercial Ethyl Cyanoacrylate adhesive mixed with acrylic acid (AA) and nitro-anthraquinone (nAq) in varying ratios. When encapsulated within 3D printed mini-vascular networks (MVNs), the n-CAs remained dormant in liquid form for up to 5 days. The contact angle between the n-CAs and the cement mortar substrate, as measured via the sessile drop technique, decreased significantly with increasing AA content. The mechanical properties (bond strength) and the polymerization hardening of the n-CAs were evaluated over a curing period of 7–21 days, via a series of pull-off tests using cement mortar cubes. The 4:1:02 (CA:AA:nAq) n-CA formulation showed a significant increase in bond strength from 14 to 21 days, with a ceiling value of 2.6 MPa, while the 2:1 (CA:AA) n-CA formulation exhibited a good bond strength after 21 days (1 MPa). Nuclear Magnetic Resonance (NMR) conducted on the n-CAs suggested the formation of several new polymeric species, whilst differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) on the pre- and post-printed MVN material confirmed no significant changes in chemistry with no evidence of polymer degradation. Considered together, the experimental results show the potential for different n-CA formulations to act efficiently as a healing agent

Immune Response After Cochlear Implantation

A cochlear implant (CI) is an electronic device that enables hearing recovery in patients with severe to profound hearing loss. Although CIs are a successful treatment for profound hearing impairment, their effectivity may be improved by reducing damages associated with insertion of electrodes in the cochlea, thus preserving residual hearing ability. Inner ear trauma leads to inflammatory reactions altering cochlear homeostasis and reducing post-operative audiological performances and electroacoustic stimulation. Strategies to preserve residual hearing ability led to the development of medicated devices to minimize CI-induced cochlear injury. Dexamethasone-eluting electrodes recently showed positive outcomes. In previous studies by our research group, intratympanic release of dexamethasone for 14 days was able to preserve residual hearing from CI insertion trauma in a Guinea pig model. Long-term effects of dexamethasone-eluting electrodes were therefore evaluated in the same animal model. Seven Guinea pigs were bilaterally implanted with medicated rods and four were implanted with non-eluting ones. Hearing threshold audiograms were acquired prior to implantation and up to 60 days by recording compound action potentials. For each sample, we examined the amount of bone and fibrous connective tissue grown within the scala tympani in the basal turn of the cochlea, the cochleostomy healing, the neuronal density, and the correlation between electrophysiological parameters and histological results. Detection of tumor necrosis factor alpha, interleukin-6, and foreign body giant cells showed that long-term electrode implantation was not associated with an ongoing inflammation. Growth of bone and fibrous connective tissue around rods induced by CI was reduced in the scala tympani by dexamethasone release. For cochleostomy sealing, dexamethasone-treated animals showed less bone tissue growth than negative. Dexamethasone did not affect cell density in the spiral ganglion. Overall, these results support the use of dexamethasone as anti-inflammatory additive for eluting electrodes able to protect the cochlea from CI insertion trauma

New trends in rehabilitation of children with ENT disorders

Negli ultimi 20 anni il miglioramento dellassistenza neonatale ha determinato un progressivo aumento dei bambini che sopravvivono in presenza di gravi malformazioni o patologie congenite. Questi bambini richiedono una riabilitazione prolungata, talora multidisciplinare e complessa. Purtroppo, unorganizzazione adeguata alla riabilitazione della disfagia, dei disturbi della comunicazione e della respirazione non è sempre disponibile, non è sempre coordinata in equipe multidisciplinari che operino sia negli ospedali che sul territorio e non è facile mantenere tutte le figure professionali coinvolte al passo con le sempre più rapide innovazioni. Scopo del presente lavoro è presentare un aggiornamento su alcuni aspetti tuttora controversi della riabilitazione in età pediatrica

Flashback analysis and avoidance in swirl burners

This study is aimed to investigate and demonstrate the feasibility and validity of various flame flashback resistance techniques for premixed fuel conditions. It presents a series of experiments to determine the impact of different configurations on flame flashback mechanisms. Experiments were performed using a 150 kW tangential swirl burner working on premixed mode with various swirl numbers; the flow field characteristics were measured by 1D LDA. The first part of the project targeted the effect of central fuel injector geometries on flame flashback mechanisms, especially combustion induced vortex breakdown (CIVB). It was found that changing the central fuel injector outside diameter can significantly alter the flame flashback mechanism. Large injector diameters result in boundary layer flashback (BLF), contrary, the use of small injectors diameter led to CIVB. Thus a dimensionless number (χ) which represent the ratio between the injector outside diameter and the nozzle inside diameter was introduced. Using this dimensionless number the critical value of transition from CIVB to BLF has been defined, the value being χ= 0.280 for Sg=1.12 and χ= 0.320 for Sg= 0.9. The second part was about the effect of using axial air injection instead of central fuel injectors. It was found that axial air jets have a considerable potential for flame stability requirements, they producing wider stability operation than that of central injectors. Moreover, the stability limits increase regarding both equivalence ratio and inlet tangential velocity. It appeared that using such air jets could reduce the combustor maintenance cost that arises due to a continuous harsh environment. However, it was found that axial air jets could enforce flame propagation during flashback via wall boundary layer. Thus, the third part of the study was about the validity of using micromeshes to improve BLF resistance in addition to axial air injection. It was found that using both techniques produced high flashback resistance for both mechanisms, i.e. CIVB and BLF

Olfactory neuroepithelium alterations and cognitive correlates in schizophrenia

BACKGROUND: Few studies have investigated alterations of olfactory neuroepithelium (ONE) as a biomarker of schizophrenia, and none its association with cognitive functioning. METHOD: Fresh ONE cells from twelve patients with schizophrenia and thirteen healthy controls were collected by nasal brushing, cultured in proper media and passed twelve times. Markers of cell proliferation (BrdU incorporation, Cyclin-D1 and p21 protein level) were quantified.Cognitive function was measured using Brief Neuropsychological Examination-2. PRIMARY OUTCOME: proliferation of ONE cells from schizophrenic patients at passage 3. Secondary outcome: association between alteration of cell proliferation and cognitive function. RESULTS: Fresh ONE cells from patients showed a faster cell proliferation than those from healthy controls at passage 3. An opposite trend was observed at passage 9, ONE cells of patients with schizophrenia showing slower cell proliferation as compared to healthy controls. In schizophrenia, overall cognitive function (Spearman's rho -0.657, p\u202f<\u202f0.01), verbal memory - immediate recall, with interference at 10\u202fs and 30\u202fs (Spearman's rho from -0.676 to 0.697, all p\u202f<\u202f0.01) were inversely associated with cell proliferation at passage 3. CONCLUSION: Fresh ONE cells collected by nasal brushing might eventually represent a tool for diagnosing schizophrenia based upon markers of cell proliferation, which can be easily implemented as single-layer culture. Cell proliferation at passage 3 can be regarded as a promising proxy of cognitive functioning in schizophrenia. Future studies should replicate these findings, and may assess whether ONE alterations are there before onset of psychosis, serving as an early sign in patients with at risk mental state

Treatment of advanced squamous cell carcinoma of the external auditory canal: Critical analysis of persistent failures in diagnosis and surgery with a competing-risk model

Background: A series of temporal bone squamous cell carcinomas (TBSCCs) was analyzed with the aim of (i) better understanding the causes for the persistent high failure rate in advanced SCCs and (ii) discussing a possible way out from this stalemate in treatment. Methods: Forty-five TBSCCs consecutively treated surgically were reviewed. Results: The 5-year cumulative incidence for postoperative local recurrence was 41.8%. At multivariable analysis, pT3-4 stages were associated with eightfold relative incidence of developing local recurrence during follow-up (sHR = 9.06, 95% confidence interval [CI] = 1.18–69.46, p = 0.034) and cause-specific death (sHR = 7.95, 95%CI = 1.01–62.27, p = 0.048). Conclusions: The poor outcome in advanced TBSCC occurred because of local recurrence due to defective resection. The fundamental pitfall of surgery on advanced TBSCC appeared to be the insufficient knowledge of microscopic tumor growth in the different sites and subsites of the temporal bone. The serial histopathological study of the en bloc surgical specimen and autopsy temporal bones seems to represent a way to enhance our understanding of these tumors