226 research outputs found

    Highly Isotactic Poly(N-butenyl-carbazole): Synthesis, Characterization, and Optical Properties

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    The synthesis of isotactic poly(N-butenyl-carbazole) (i-PBK) by using homogeneous isospecific Ziegler-Natta catalytic system is reported. The achieved polymer is crystalline and shows, to DSC and X-ray analysis, two distinct crystalline phases.i-PBK FTIR spectrum and X-ray diffraction pattern are compared with those of poly(N-vinylcarbazole) (PVK). The observed differences are tentatively associated with higher flexibility of thei-PBK chains due to the alkylene group connecting the carbazole group to the main chain.i-PBK optical properties are also compared with those of PVK and isotactic poly(N-pentenyl-carbazole) (i-PPK), a higher homologue ofi-PBK recently used as emitting layer in organic light emitting diodes (OLEDs) showing white light emission. The close similarity of the fluorescence spectra ofi-PBK andi-PPK is a promising basis for optical applications of this polymer

    RF-powered UHF-RFID analog sensors platform

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    An RF powered UHF-RFID passive sensors platform was realized using discrete components and printed antennas designed to resonate at 868 MHz, used both for energy harvesting and data transmission. The tests demonstrate the possibility for the system to operate autonomously within the reading range of a standard RFID reader, that acts both as the RF power source and the receiver of the data stored in the tag user memory. The microcontroller can be interfaced on the same substrate with a sensor made of polymeric materials, sensible to physical parameters or chemical agents. RF-powered UHF-RFID analog sensors platform (PDF Download Available). Available from: http://www.researchgate.net/publication/279193365_RF-powered_UHF-RFID_analog_sensors_platform [accessed Sep 14, 2015]

    Surgical vls therapy of oesophageal achalasia in pediatric age: four case reports

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    The Authors present a retrospective review of their record of cases, characterized by 4 cases of achalasia in which it was performed a Heller myotomy with front fundoplication (Thall) in laparoscopic approach in the period from 2012 to 2019. In paediatric achalasia, the laparoscopic Heller myotomy seems to be the best treatment because of its multiple advantages offered by the minimally invasive technique. First of all, thanks to the video-technique, which allows a complete and extended myotomy, the accuracy of this operation is maximized; moreover, the post-operative pain is widely reduced, thanks to the minimal dissection and traction of the tissues; finally, but not negligible, this approach ensures a better aesthetic result than the classic open technique. With regard to the front fundoplication, the Authors suggest that it is mandatory because, even if it extends the operating time, it ensures a natural protection to the myotomy herniated mucosa and avoids gastro-oesophageal reflux, which often occurs after the surgical correction, thus obliging to perform a reoperation

    Papillary thyroid carcinoma in paediatric age

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    In children, differentiated thyroid carcinoma is a rare condition. Early diagnosis is not always easy, because of the lack of clinical symptoms, but it has a pivotal role in performing a correct therapeutic process. The study describes three cases of papillary thyroid carcinoma. None of the three patients had a positive familiarity or exposure to risk factors. In two cases, the tumor occurred as a non-injurious swelling in the anterior cervical region, in the other case it occurred with a latero-cervical lymphadenopathy that had been persistent for a year. In the first two patients we made a certain diagnosis by the needle aspiration of the thyroid nodule; in the other case the diagnosis was made by surgical exeresis and histological analysis of the lymph nodes. We also performed blood chemistry and hormonal tests, neck ultrasound, chest x-ray. The three children underwent total thyroidectomy and two of them also underwent rightsided cervical lymph node exeresis because there was the presence of metastasis. In our experience, the best therapeutic strategy for children with differentiated thyroid carcinoma is the total thyroidectomy, followed or not by latero-cervical lymph node exeresis and radioiodiotherapy. The removal of the whole gland reduces the risk of relapse

    Complications of the “nuss procedure” in pectus excavatum

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    During the pediatric age range, one the most frequent deformities of the chest wall are Pectus Excavatum (PE). Currently the treatment of choice for PE is surgical intervention following the Nuss procedure. In this study, we present a description of the complications associated with surgical treatment of PE with the Nuss technique, in patients with symmetrical or asymmetrical deformity, in different stages of disease severity. The study was conducted in collaboration with the Pediatric Hospital “Istituto G. Gaslini” of Genoa. We analyzed a cohort of 402 patients (334 males and 68 females), who underwent corrective surgery between 2005 and 2018. Within this group of patients, we observed 82 cases with complications (20.39%), 20 of which were intraoperative (4.98%) and 62 postoperative (15.42%). For the evaluation of complications, this group was arbitrarily divided into patients with symmetric and asymmetric Pectus and in patients with mild, moderate and severe Pectus using Haller's index. Although a small group of patients presented complications, overall results from data analysis show that the Nuss technique represents the preferred surgical procedure for the treatment of PE, in agreement with literature. Furthermore, in our results show no correlation between asymmetry or severity of PE with complication related to the surgery

    Minimally invasive treatment of urolithiasis in children: evaluation of the use of flexible ureterorenoscopy and laser lithotripsy

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    Urolithiasis is a multifactorial disease; in recent years, its incidence has gradually increased in pediatric age. Among the factors involved in urolithiasis pathophysiology, urinary tract anomalies and metabolic diseases are the most relevant, although ethnicity and environmental factors may have an important role. The advances in technology and miniaturization of endoscopic devices have permitted the use of Retrograde Intrarenal Surgery (RIRS) to treat kidney and ureteral stones. Nowadays, flexible ureterorenoscopy and laser lithotripsy, which are techniques that have been applied in the management of adult upper urinary tract disorders, are also used in children as a minimally invasive treatment of urolithiasis with encouraging, effective and safe results. The Authors report a retrospective review of their record of cases considering 21 pediatric urolithiasis treatment procedures performed between October 2017 and April 2019 in a total of 17 patients (10 males and 7 females). Six procedures involved the use of the flexible ureterorenoscope (FURS) while in 15 procedures the application of the laser fiber was used (FURSL). A case of laser lithotripsy for bladder stone was included. The average age of patients was 10.5 years (2-18 years). The renal pelvis dilatation pretreatment was evaluated in post-operative follow-up. From the evaluation of the sample in analysis, the use of RIRS has good results in the treatment of paediatric urolithiasis, emerging as a valid option in the management of the paediatric population in terms of efficacy and safety, with an improvement in patient outcomes
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