29 research outputs found

    Large Horizontal Near-field Scanner based on a Non-tethered Unmanned Aerial Vehicle

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    A horizontal planar scanner with an approximate size of 40 m x 40 m has been implemented using the Unmanned Aerial Vehicle (UAV) technology. The UAV is not wired to the ground to maintain the flexibility and short setup time of a non-tethered flight. In this configuration, the UAV-mounted continuous-wave source is not phase-locked to the on-the-ground receiver. A dual-polarized reference antenna placed on the ground is hence used to retrieve the relevant phase information. The presented approach has been applied on the Pre - Aperture Array Verification System (Pre -AAVS1) of the Square Kilometre Array, which is a digital beamformed array with 16 active elements. An inverse source technique has been applied on measured Near-Field (NF) data acquired on two different sets of points (one for each electric field component) from all the receiver channels. In this way, Embedded Element Patterns (EEPs), array calibration coefficients and pattern have been determined from NF data only. The achieved results have been validated using a complementary set of Far-Field (FF) measurements and simulations

    Diabetic ketoacidosis at the onset of disease during a national awareness campaign: a 2-year observational study in children aged 0-18 years

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    After a previous survey on the incidence of diabetic ketoacidosis (DKA) at onset of type 1 diabetes in children in 2013-2014 in Italy, we aimed to verify a possible decline in the incidence of DKA at onset during a national prevention campaign

    Receiver design for the REACH global 21-cm signal experiment

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    We detail the the REACH radiometric system designed to enable measurements of the 21-cm neutral hydrogen line. Included is the radiometer architecture and end-to-end system simulations as well as a discussion of the challenges intrinsic to highly-calibratable system development. Following this, we share laboratory results based on the calculation of noise wave parameters utilising an over-constrained least squares approach demonstrating a calibration RMSE of 80 mK for five hours of integration on a custom-made source with comparable impedance to that of the antenna used in the field. This paper therefore documents the state of the calibrator and data analysis in December 2022 in Cambridge before shipping to South Africa.Comment: 30 pages, 19 figure

    A Multicenter Retrospective Survey regarding Diabetic Ketoacidosis Management in Italian Children with Type 1 Diabetes

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    We conducted a retrospective survey in pediatric centers belonging to the Italian Society for Pediatric Diabetology and Endocrinology. The following data were collected for all new-onset diabetes patients aged 0-18 years: DKA (pH < 7.30), severe DKA (pH < 7.1), DKA in preschool children, DKA treatment according to ISPAD protocol, type of rehydrating solution used, bicarbonates use, and amount of insulin infused. Records (n = 2453) of children with newly diagnosed diabetes were collected from 68/77 centers (87%), 39 of which are tertiary referral centers, the majority of whom (n = 1536, 89.4%) were diagnosed in the tertiary referral centers. DKA was observed in 38.5% and severe DKA in 10.3%. Considering preschool children, DKA was observed in 72%, and severe DKA in 16.7%. Cerebral edema following DKA treatment was observed in 5 (0.5%). DKA treatment according to ISPAD guidelines was adopted in 68% of the centers. In the first 2 hours, rehydration was started with normal saline in all centers, but with different amount. Bicarbonate was quite never been used. Insulin was infused starting from third hour at the rate of 0.05-0.1 U/kg/h in 72% of centers. Despite prevention campaign, DKA is still observed in Italian children at onset, with significant variability in DKA treatment, underlying the need to share guidelines among centers

    The low frequency receivers for SKA 1-low: Design and verification

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    The initial phase of the Square Kilometre Array (SKA) [1] is represented by a ~10% instrument and construction should start in 2018. SKA 1-Low, a sparse Aperture Array (AA) covering the frequency range 50 to 350 MHz, will be part of this. This instrument will consist of 512 stations, each hosting 256 antennas creating a total of 131,072 antennas. A first verification system towards SKA 1-Low, Aperture Array Verification System 1 (AAVSl), is being deployed and validated in 2017

    Consensus sulla lotta allo stigma nell\u2019obesit\ue0

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    People with obesity daily face a pervasive and ubiquitous form of stigma on weight that damages health and reduces the likelihood of receiving adequate care. The stigma is reinforced by outdated ideas on body weight regulation and lack of up-to-date scientific knowledge. The prevailing opinion that obesity is a choice that can be avoided misleads public health policies, confuses messages in the media, undermines access to treatments and compromises research. The stigma is a serious obstacle, therefore tackling it is not only a matter of human rights and social justice, but a way to promote prevention and treatment. A large group of international experts examined the evidence on the causes and consequences of the stigma and developed a Consensus to end it, raising awareness among health workers, politicians and public opinion, encouraging training and facilitating a new narrative on obesity. Successful therapies for all people with obesity can arise from the shared struggle against the stigma

    Solitary floating vena caval thrombus as a late recurrence of renal cell carcinoma

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    We report an unusual case of solitary thrombus floating in the inferior vena cava (IVC) in a patient who underwent radical nephrectomy for a renal cell carcinoma (RCC) of the right kidney extended into the renal vein with no capsular and perinephric tissue invasion (pT3b). Twenty months after surgery, a routine computed tomography scan identified an intraluminal mass floating in the IVC. Cavotomy and thrombectomy with no caval resection were successfully performed. A review of the literature showed only three previous published cases of RCC recurring in the IVC only, with no local recurrence or distant metastases. We outline the possible etiology of these unusual and solitary recurrences in the IVC and we emphasize the need for a strict surveillance for all patients with RCC and especially for those with pT1b, pT2 and pT3 disease. An early diagnosis of this rare recurrence can permit an easy removal of the thrombus with no caval resection and graft replacement, making this disease potentially curable by surgery

    Early-stage hepatocellular carcinoma in patients with cirrhosis: long-term results of percutaneous image-guided radiofrequency ablation

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    PURPOSE:To perform a prospective, intention-to-treat clinical trial to determine the long-term survival rates of patients with hepatic cirrhosis and early-stage hepatocellular carcinoma (HCC) in whom percutaneous image-guided radiofrequency (RF) ablation was used as the sole first-line anticancer treatment. MATERIALS AND METHODS: The study was performed with approval of the ethics committee, and written informed consent was obtained for all patients. From June 1, 1996, to January 1, 2003, 206 patients (143 men, 63 women; age range, 51-81 years; mean age, 67 years +/- 7) who were excluded from surgery and who had Child class A or B cirrhosis with either a single HCC less than or equal to 5 cm in diameter or multiple (as many as three) HCCs less than or equal to 3 cm in diameter each were enrolled. RF ablation was performed in 187 (91%) of 206 patients; 19 (9%) were excluded from RF treatment because of unfavorable tumor location. Follow-up ranged from 3 to 78 months (mean, 24 months +/- 21) and included measurement of alpha-fetoprotein level, ultrasonography at 3-month intervals, and spiral computed tomography at 6-month intervals. Patients were observed for recurrence of the treated tumor and for the emergence of new HCC tumors. Survival probabilities were estimated with the Kaplan-Meier method, and differences between survival curves were evaluated with the log-rank test. RESULTS: At the end of the study, 145 patients were alive, and 61 were dead. In the intention-to-treat analysis, overall survival rates were 97% at 1 year, 67% at 3 years, and 41% at 5 years. Median survival was 49 months. In the 187 patients treated with RF ablation, overall survival rates were 97% at 1 year, 71% at 3 years, and 48% at 5 years. Median survival was 57 months. The difference between the two survival curves was not statistically significant (P=.5094). Survival of patients treated with RF ablation was dependent on Child class (P=.0006) and tumor multiplicity (P=.0133). Patients who had Child class A cirrhosis with solitary HCC (n=116) had 1-, 3-, and 5-year survival rates of 100%, 89% and 61%; median survival was 65 months. The 1-, 3-, and 5-year recurrence rates were 14%, 49%, and 81% for the emergence of new tumors and 4%, 10%, and 10% for local tumor progression. CONCLUSION: RF ablation is an effective first-line treatment for cirrhotic patients with early-stage HCC who were excluded from surger
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