285 research outputs found

    Sustainable Recycling of Insoluble Rust Waste for the Synthesis of Iron-Containing Perovskite-Type Catalysts

    Get PDF
    Insoluble rust waste from the scraping of rusted iron-containing materials represents a cheap, eco-friendly, and available source of iron. LaFeO3 perovskite-type powders were successfully prepared by solution combustion synthesis using rust waste from an electricity transmission tower manufacturer. Solution combustion synthesis enabled introduction of this insoluble iron precursor directly into the final product, bypassing complex extraction procedures. Catalytic activity in the propylene oxidation of the waste-derived LaFeO3 with stoichiometric Fe/La ratio was almost identical to the commercial iron nitrate-derived LaFeO3 , thus demonstrating the viability of this recycling solution. The amount of waste iron precursor was varied and its effect on the powder properties was investigated. A lesser stoichiometric amount of precursor produced a LaFeO3 -La2O3 binary system, whereas a higher stoichiometric amount led to a LaFeO3 -Fe2O3 binary system. Catalytic activity of iron-rich compositions in the propylene oxidation was only slightly lower than the stoichiometric one, whereas iron-poor compositions were much less active. This eco-friendly methodology can be easily extended to other iron perovskites with different chemical compositions and to other iron-containing compounds

    Spontaneous internal carotid artery rupture during neck dissection in osteogenesis imperfecta patient.

    Get PDF
    Several connective tissue disorders are associated with vascular wall abnormalities, including spontaneous dissection of the cervical arteries. Osteogenesis imperfecta (OI) is a hereditary disorder, with rare neurovascular complications, which potentially lead to life-threatening events.We presented a case of spontaneous internal carotid artery (ICA) rupture that occurred in a 52-year-old-woman, suffering from OI type I, and who underwent a bilateral modified radical neck dissection (mRND) plus total thyroidectomy for a T4aN1b thyroid cancer. During mRND, an ICA's spontaneous rupture occurred.Histopathologic report suggested a structural defect of the arterial wall without cancer infiltration. The patient did not experience any neurologic complications.Head and neck surgeons have to be aware about early clinical recognition of possible cervical vascular abnormalities, in patients with connective tissue disorders, potentially responsible for dramatic vascular rupture during cervical surgical procedures

    First bite syndrome as presenting symptom of parapharyngeal adenoid cystic carcinoma.

    Get PDF
    First bite syndrome refers to the development of pain in the parotid region after the first bite of each meal.A man was referred to our institution with first bite syndrome as his only symptom. Magnetic resonance imaging of the head and neck revealed a deep lobe parotid mass in close contact with the external carotid artery. Computed tomography guided fine needle biopsy indicated adenoid cystic carcinoma. Total parotidectomy was performed, with en bloc resection of the infiltrated external carotid artery and a selective neck dissection of levels Ib to III. High-weight ion radiotherapy was administered post-operatively.First bite syndrome has hitherto only been described following parapharyngeal space surgery. We present the first case of parotid gland adenoid cystic carcinoma presenting with first bite syndrome as the only symptom. The presence of first bite syndrome should prompt the clinician to investigate the parapharyngeal space and deep lobe of the parotid gland, especially in the absence of other signs or symptoms

    Experimental evaluation of thermal properties of grouting materials

    Get PDF
    Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In recent years, the use of techniques of heating and space cooling with ground coupled heat pumps is spreading. This technology, also known as low energy geothermal cooling and heating, plans to use, as a heat source, the subsoil, due to its ability to maintain its temperature constant at values close to the average annual temperature of the locality. The heat exchange with the ground is done by probes that generally consist of U-shaped tubes (single or double) made of plastic and placed in a vertical hole, drilled in the subsoil and filled with grouting materials. For an optimal exploitation of this technology, the use of high thermal conductivity grouting materials is fundamental to minimize thermal resistance and facilitate the heat exchange between the probe and ground. This study is aimed at the thermal analysis of sealant mortar (usually a mixtures of bentonite and cement with addition of sand) used in geothermal cooling and heating. In particular, thermal conductivity and diffusivity measurements were performed on available materials using the so called Hot Disk Thermal Constants Analyser.dc201

    Dissection with harmonic scalpel versus cold instruments in parotid surgery.

    Get PDF
    The harmonic scalpel (HS) has been used successfully in several head and neck surgical procedures. Some authors highlighted its advantages in reducing operative time, blood loss, and damages to surrounding tissue. In our study, we compared the results obtained during parotidectomy using the HS with the traditional approach to determine the benefits of the HS.130 patients with benign parotid tumors were enrolled and randomized into two groups for this prospective study. 63 patients underwent HS parotidectomy, and 67 patients received a parotidectomy using cold instruments and bipolar electrocautery hemostatic control (CI). 20 HS and 2 CI patients did not meet the inclusion criteria requirements, and were excluded.The admission time was significantly shorter in the HS group than the CI group (3.9 ± 1.2 days and 4.7 ± 1.4 days, respectively, p < 0.01). In the early post-operative period, 84\% of HS patients and 60\% of CI cases showed no facial nerve impairment (p = 0.01). Significantly more CI patients than HS patients showed the onset of Frey's syndrome (29\% and 9\%, respectively, p = 0.01). Multivariate stepwise regression analysis confirmed the reduction in admission length (Odds Ratio (OR): 0.62; p = 0.02) and the lower risk of Frey's syndrome (OR: 0.29; p = 0.04) in HS compared to CI parotidectomies.In parotid surgery, the HS is useful in preventing Frey's syndrome and reducing early transitory facial nerve dysfunction and admission times, and results in decreased medical costs and increased quality of life

    Role of contrast-enhanced ultrasound (CEUS) in paediatric practice: an EFSUMB position statement

    Get PDF
    The use of contrast-enhanced ultrasound (CEUS) in adults is well established in many different areas, with a number of current applications deemed off-label, but the use supported by clinical experience and evidence. Paediatric CEUS is also an off-label application until recently with approval specifically for assessment of focal liver lesions. Nevertheless there is mounting evidence of the usefulness of CEUS in children in many areas, primarily as an imaging technique that reduces exposure to radiation, iodinated contrast medium and the patient-friendly circumstances of ultrasonography. This position statement of the European Federation of Societies in Ultrasound and Medicine (EFSUMB) assesses the current status of CEUS applications in children and makes suggestions for further development of this technique

    Fistola faringocutanea dopo laringectomia totale: analisi dei fattori di rischio, della prognosi e delle modalitĂ  di trattamento

    Get PDF
    In questo studio sono state valutate l’incidenza, i fattori di rischio e le modalità di trattamento in pazienti con fistola faringocutanea dopo laringectomia totale primaria e di salvataggio. Nel periodo compreso tra gennaio 1999 e ottobre 2014, 352 pazienti affetti da carcinoma squamocellulare della laringe sono stati sottoposti a laringectomia totale. Il decosro postoperatorio di 86 pazienti è stato complicato dall’insorgenza di fistola fainrogcutanea. Questi sono stati comparati in uno studio caso-controllo con 86 pazienti selezionati tramite software, fra quelli che non avevano sviluppato la fistola salivare. L’incidenza globale di fistola dopo laringectomia totale è stata del 24,4%, rispettivamente abbiamo registrato incidenze del 19,0%, del 28,6% e del 30,3% dopo laringectomia totale primaria, dopo radioterapia e dopo radiochemioterapia. L’analisi multivariata ha rivelato che per ipoalbuminemia ≤3,5 g/dL, per pregressa radioterapia e radiochemioterapia il rischio relativo di sviluppo di fistola è stato rispettivamente 2,47, 3,09 e 7,69. In caso di laringectomia totale di salvataggio abbiamo registrato una comparsa precoce della fistola entro i primi 10 giorni postoperatori. Le modalità di trattamento della fistola faringocutanea sono risultate essere significativamente differenti in caso di laringectomia totale primaria, dopo radioterapia e dopo radiochemioterapia. Infatti, mentre nel primo caso è stato sufficiente un trattamento di tipo conservativo (93,55%), dopo chemioradioterapia ha prevalso il ricorso a tecniche chirurgiche ricostruttive con lembi regionali (58,82%). Nel caso dei pazienti radiotrattati, le opzioni terapeutiche della fistola sono risultate essere equamente distribuite tra quella medica, eventualmente con l’aggiunta dell’ossigenoterapia iperbarica, e quella chirurgica ricostruttiva. La conoscenza dei fattori di rischio soggettivi e il loro valore prognostico, permettono al chirurgo di pianificare le strategie preventive al fine di ridurre il rischio di formazione della complicanza e, conseguentemente, dei tempi di degenza e dei relativi costi

    Designing a High-Power Sodium-Ion Battery by in Situ Metal Plating

    Get PDF
    Sodium ion batteries represent a drop-in technology and a more sustainable alternative to Li-ion, but higher energies and power levels are required to meet the demands required by a greener electrification. Here, the design of an anode-free sodium-ion battery is presented and its performances discussed in terms of reduced mass and high power capabilities. The cell consists of an Iron Hexacyanoferrate - reduced Graphene Oxide composite as cathode material whose synthesis is tailored to achieve minimal structural defects (3%) and water content. Its high-potential redox couple FeLS(C) is stabilized at high rates, granting the full cell with high discharge voltage and power. As negative substrate, a carbon coated aluminum foil was adopted for in situ plating/stripping of Na metal, showing very small voltage hysteresis up to an applied current of 2 mA/cm2. Overall, this simplified full cell architecture can deliver up to 340 Wh/kg and 500 W/kg at nominal 1C retaining 80% in 250 cycles, with the possibility of delivering 9000 W/kg at 20C. Bridging the boundaries between batteries and supercapacitors, this research aims to expand the range of possible applications for Na-ion technology

    Supracricoid partial laryngectomy as salvage surgery for radiation therapy failure.

    Get PDF
    The main concern in the treatment of laryngeal carcinomas is tumor control with preservation of laryngeal functions. We believe that salvage supracricoid partial laryngectomy (SPL) should be carefully considered in selected cases of radiotherapy failure, because it can offer the possibility of achieving adequate tumor control with preservation of laryngeal functions.A series of 31 patients who underwent an SPL as salvage procedure after radiotherapy failure was reviewed.Locoregional control rate was 75\%, with 60\% 5-year overall survival; no patients were lost to follow-up, and a death-from-disease rate of 19.35\% was recorded. Restoration of laryngeal functions was achieved in 89.29\% of the patients. No statistically significant differences were found in locoregional control regarding anterior commissure involvement, elective neck dissection versus wait-and-see policy, pathologic positive neck disease, and restage I-II versus restage III-IV.The oncologic and functional results indicate the consistency of salvage SPL, proposing this type of operation as a serious alternative to total laryngectomy in carefully selected cases

    Prognostic role of pneumonia in supracricoid and supraglottic laryngectomies.

    Get PDF
    The goal of this study was to identify host and tumour factors associated with postoperative pneumonia (PP) in a selected population of laryngeal cancer patients, treated by partial laryngectomy in 20 years at our Institution and to assess its potential prognostic impact. Clinical records of 416 consecutive patients were retrospectively reviewed. Tobacco consumption, body mass index (BMI), previous pulmonary disease, age, sex, preoperative blood gas analysis values, tumour stage and type of surgery were tested as potential risk factors for PP. Finally, the prognostic impact of these variables, including PP, in terms of disease-free and actuarial survival by Kaplan-Meier and Cox analyses were evaluated. PP developed in 73 patients (16.8\%). We identified two groups of patients: 26 patients experienced an early PP within the first 7-9 days after surgery, whilst 44 experienced an ab ingestis PP following attempts of oral food intake restoration, three patients died for PP related sepsis. At multivariate Cox analysis, age older than 60 years and BMI greater than 30 were statistically associated with early PP; whereas male gender and laryngectomy with neck dissection were statistically related to a higher risk of ab ingestis PP. Interestingly, the occurrence of early PP was a negative independent prognostic factor for 5-years disease-free and actuarial survival (p=0.049 and p=0.001, respectively). The occurrence of early-onset pneumonia in laryngeal cancer patients selected for conservative laryngectomies is predictable and associated with poor clinical outcome
    • …
    corecore