3,616 research outputs found

    Entangled single-wire NiTi material: a porous metal with tunable superelastic and shape memory properties

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    NiTi porous materials with unprecedented superelasticity and shape memory were manufactured by self-entangling, compacting and heat treating NiTi wires. The versatile processing route used here allows to produce entanglements of either superelastic or ferroelastic wires with tunable mesostructures. Three dimensional (3D) X-ray microtomography shows that the entanglement mesostructure is homogeneous and isotropic. The thermomechanical compressive behavior of the entanglements was studied using optical measurements of the local strain field. At all relative densities investigated here (∼\sim 25 - 40%\%), entanglements with superelastic wires exhibit remarkable macroscale superelasticity, even after compressions up to 25%\%, large damping capacity, discrete memory effect and weak strain-rate and temperature dependencies. Entanglements with ferroelastic wires resemble standard elastoplastic fibrous systems with pronounced residual strain after unloading. However, a full recovery is obtained by heating the samples, demonstrating a large shape memory effect at least up to 16% strain.Comment: 31 pages, 10 figures, submitted to Acta Materiali

    Tongue Reconstruction with Buccinator Myomucosal Island Flaps: Technical Considerations, Oncologic Safety, Functional Outcomes and QoL Assessment—A Retrospective Observational Study

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    The objective of this study was to investigate the effectiveness of buccinator myomucosal island flaps for tongue reconstruction following malignant tumor resections. A retrospective study was performed on 52 patients who underwent tongue reconstructions with buccinator myomucosal island flaps between 2012 and 2020. We reviewed the flap type and size, harvesting time, recipient- and donor-site complications, postoperative oncologic outcomes, functional recovery and QoL assessment. All of the flaps were transposed successfully without any total flap loss. Neither in the primary site nor in the neck were cancer relapses observed. An evaluation of the sensitivity revealed that 96.1% of patients experienced a recovery of touch, two-point and pain sensations. There were significant differences between the flap and the native mucosa in terms of the tactile (p < 0.001), pain (p < 0.001) and two-point (p < 0.001) thresholds. The average swallowing score recorded was 6.1 out of 7, with only minor complaints. The quality of life assessments demonstrated high scores across physical (24.5 out of 28), social (25.8 out of 28), emotional (20.3 out of 24) and functional (25 out of 28) aspects. The present study showed how buccinator myomucosal island flaps represent an effective and functional tongue reconstructive option, requiring a short operative time with a low rate of donor site morbidity, and with evidence of long-term oncologic safety and high quality of life

    Minimally Invasive Lung Tissue Differentiation Using Electrical Impedance Spectroscopy : A Comparison of the 3- and 4-Electrode Methods

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    Altres ajuts: Secretariat d'Universitats i Recerca, Generalitat de Catalunya; the European Social Fund.Multiple imaging techniques are used for the diagnosis of lung diseases. The choice of a technique depends on the suspected diagnosis. Computed tomography (CT) of the thorax and positron emission tomography (PET) are imaging techniques used for the detection, characterization, staging and follow-up of lung cancer, and these techniques use ionizing radiation and are radiologist-dependent. Electrical impedance spectroscopy (EIS) performed through a bronchoscopic process could serve as a minimally invasive non-ionizing method complementary to CT and PET to characterize lung tissue. The aim of this study was to analyse the feasibility and ability of minimally invasive EIS bioimpedance measures to differentiate among healthy lung, bronchial and neoplastic lung tissues through bronchoscopy using the 3- and 4-electrode methods. Tissue differentiation was performed in 13 patients using the 4-electrode method (13 healthy lung, 12 bronchial and 3 neoplastic lung tissues) and the 3-electrode method (9 healthy lung, 10 bronchial and 2 neoplastic lung tissues). One-way analysis of variance (ANOVA) showed a statistically significant difference (P < 0.001) between bronchial and healthy lung tissues for both the 3- and 4-electrode methods. The 3-electrode method seemed to differentiate cancer types through changes in the cellular structures of the tissues by both the reactance (Xc) and the resistance (R). Minimally invasive measurements obtained using the 3-electrode method seem to be most suitable for differentiating between healthy and bronchial lung tissues. In the future, EIS using the 3-electrode method could be a method complementary to PET/CT and biopsy in lung pathology diagnosis

    RELATIONSHIP BETWEEN LEVEL OF CONTAMINATION ON HIDE OF ANIMALS PRESENTED FOR SLAUGHTER AND CONTAMINATION ON THE RESULTANT CARCASSES

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    The hide and viscera of cattle entering a slaughter facility are potential sources of contamination of carcasses including significant pathogens such as Escherichia coli O157:H7, Campylobacter spp. and Salmonella spp. If evisceration is correctly performed, visceral contents do not therefore contribute significantly to the overall contamination of the carcass. However, it is much more difficult to restrict contamination from the hide. The aim of this work is to investigate the relationships between the levels of dirt and contamination on the hide of animals presented for slaughter and the levels of contamination on the resultant carcasses. Cattle were visually inspected in the lairage of 2 abattoirs and assigned to a category ranging from 1 (very clean) to 5 (very dirty) depending on the observed cleanliness of the hide. Samples of hides and carcasses were taken from 50 animals for enumerate total viable counts, Enterobacteriaceae and Escherichia coli. The results show that there is a direct correlation between animal dirtiness and total bacterial count of the carcasses

    In situ monitoring and quantitative determination of R27 plasmid conjugation

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    Horizontal gene transfer (HGT) by plasmid conjugation is a major driving force in the spread of antibiotic resistance among Enterobacteriaceae. Most of the conjugation studies are based on calculation of conjugation ratios (number of transconjugants/number of donors) after viable counting of transconjugant and donor cells. The development of robust, fast and reliable techniques for in situ monitoring and quantification of conjugation ratios might accelerate progress in understanding the impact of this cellular process in the HGT. The IncHI1 plasmids, involved in multiresistance phenotypes of relevant pathogens such as Salmonella and E. coli, are distinguished by the thermosensitivity of their conjugative transfer. Conjugation mediated by IncHI1 plasmids is more efficient at temperatures lower than 30 °C, suggesting that the transfer process takes place during the environmental transit of the bacteria. In this report, we described a methodology to monitor in situ the conjugation process during agar surface matings of the IncHI1 plasmid R27 and its derepressed derivative drR27 at different temperatures. A three-color-labeling strategy was used to visualize the spatial distribution of transconjugants within the heterogeneous environment by epifluorescence and confocal microscopy. Moreover, the fluorescent labelling was also used to quantify conjugation frequencies in liquid media by flow cytometry

    Obstructive sleep apnoea/hypopnoea syndrome: Relationship with obesity and management in obese patients

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    SUMMARY Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disease characterised by upper airway obstruction during sleep, quite frequent in the general population, even if underestimated. Snoring, sleep apnoea and diurnal hypersomnia are common in these patients. Central obesity plays a key role: it reduces the size and changes the conformation of the upper airways, besides preventing lung expansion, with consequent reduction of lung volumes. Furthermore, obese people are also resistant to leptin, which physiologically stimulates ventilation; as a result, this causes scarce awakening during apnoea. OSAHS diagnosis is based on the combination of clinical parameters, such as apnoea/hypopnoea index (AHI), medical history, physical examination and Mallampati score. The first objective reference method to identify OSAHS is polysomnography followed by sleep endoscopy. Therapy provides in the first instance reduction of body weight, followed by continuous positive airway pressure (CPAP), which still remains the treatment of choice in most patients, mandibular advancement devices (MAD) and finally otolaryngology or maxillofacial surgery. Among surgical techniques, central is barbed reposition pharyngoplasty (BRP), used in the field of multilevel surgery

    Do olfactory and gustatory psychophysical scores have prognostic value in COVID-19 patients? A prospective study of 106 patients

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    Background: The lack of objective data makes it difficult to establish the prognostic value of chemosensitive disorders in coronavirus disease 2019 (COVID-19) patients. We aimed to prospectively monitor patients diagnosed with COVID-19 to see if the severity of olfactory and gustatory dysfunction associates with subsequent disease severity. Methods: Multicentre prospective study that recruited 106 COVID-19 subjects at diagnosis. Chemosensitive functions were assessed with psychophysical tests within 4 days of clinical onset, at 10 and 20 days. Daily body temperature and oxygen saturation were recorded as markers of disease severity alongside need for hospitalisation. The correlation between olfactory and gustatory scores and disease severity was assessed with linear regression analysis. Results: At T0, 71 patients (67%) presented with olfactory dysfunction while gustatory impairment was detected in 76 cases (65.6%). Chemosensitive disorders gradually improved over the observation period. No significant correlations were found between T0 chemosensitive scores and final disease severity. The correlation between olfactory scores and fever proved significant at T2 (p = 0.05), while the relationship with gustatory scores was significant at T1 (p = 0.01) and T2 (p < 0.001), however neither was clinically relevant. The correlation between chemosensitive scores and oxygen saturation was significant only for taste at T2 (p < 0.001). Logistic regression analysis found significant correlations between olfactory impairment severity and need for hospitalization at T2 (OR 3.750, p = 0.005). Conclusions: Initial objective olfactory and gustatory scores do not seem to have a significant prognostic value in predicting the severity of the COVID-19 course; however, persistence of olfactory dysfunction at 20 days, associated with a more severe course. Unfortunately, olfactory and gustatory dysfunction do not seem to hold prognostic value at the time of initial diagnosis
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