Diamond FET: high-speed optical switch

A high-speed optical switch based on an ultraviolet sensitive surface channel MESFET fabricated on polycrystalline diamond has been developed. Saturation response to a nanosecond pulsed excimer laser has been demonstrated. Such an opaque gate three-terminal device is suitable for power applications where electromagnetic interference on power control interfaces is not negligible

Polycrystalline diamond UV-triggered MESFET receivers

Optically triggered UV sensitive receivers were fabricated on polycrystalline diamond as surface channel MESFETs. Opaque gates with asymmetric structure were designed in order to improve charge photogeneration mainly within the gate–drain region. Photogenerated holes contributed to the channel charge by assistance of the local electric field, in such a way improving the current signal at the drain contact. The sensitivity to UV light is demonstrated by using 3 ns wide laser pulses at 193 nm, well over the diamond bandgap. The receiver transient response to such laser pulses shows that the photogeneration process is only limited by the pulse rise time and charge collection at the drain contact completed in a time scale of a few nanoseconds. Such opaque gate three-terminal devices are suitable for application in emerging photonic technologies, for power-management system optical receivers, where copper wires and EM shielding can be replaced by lightweight optical fibers

Long-term patient-reported outcomes after anti-reflux surgery for gastroesophageal reflux disease and hiatal hernia repair: a single-center experience

Background: Patients with gastroesophageal reflux disease (GERD) and hiatal hernia who are candidates for surgery should be treated with minimally invasive partial or total fundoplication. As data on long-term clinical and functional outcomes after laparoscopic surgery for GERD are limited, the aim of this study was to evaluate the long-term effectiveness of fundoplication in terms of patient-reported symptoms and proton pump inhibitor (PPI) use. Methods: The data of 88 patients who underwent laparoscopic anti-reflux surgery for GERD between January 2007 and September 2020 were retrospectively reviewed. Preoperative and postoperative patient-reported outcomes were investigated after surgery using a 13-items Likert-Scale questionnaire based on the frequency (events/week) and severity of typical and atypical symptoms, dysphagia, and dyspepsia. Furthermore, variations in the use of PPIs were investigated as a secondary endpoint. Results: A total of 76 patients participated in the questionnaire survey. The median follow-up duration was 77 (2-165) months. The postoperative rate of mild and severe typical symptoms was significantly lower than the preoperative rate (P10 years after surgery. Conclusions: In this cohort of patients, laparoscopic anti-reflux fundoplication reduced the rate typical and atypical symptoms of GERD. However, surgery appeared to have no impact on PPI intake over time

RF power performance evaluation of surface channel diamond MESFETs

We experimentally investigate the large-signal radio frequency performances of surface-channel p-type diamond MESFETs fabricated on hydrogenated polycrystalline diamond. The devices under examination have a coplanar layout with two gate fingers, total gate periphery of 100 μm; in DC they exhibit a hole accumulation behavior with threshold voltage Vt ≈ 0-0.5 V and maximum drain current density of 120 mA/mm. The best small-signal radio frequency performances (maximum cutoff or transition frequency fT and oscillation frequency fmax) were obtained close to the threshold and were of the order of 6 and 15 GHz, respectively. The power radio frequency response was characterized by driving the devices in class A at an operating frequency of 2 GHz and identifying through the active load-pull technique the optimum load for maximum power added efficiency. A power gain in linearity of 8 dB and an output power of approximately 0.2 W/mm with 22% power added efficiency were obtained on the optimum load impedance at a bias point VDS = −14 V, VGS = −1 V. To the best of our knowledge, these are the first large signal measurements ever reported for surface MESFET on polycrystalline diamond, and show the potential of such technology for the development of microwave power device

Clinical nutrition in surgical oncology: Young AIOM-AIRO-SICO multidisciplinary national survey on behalf of NutriOnc research group

Malnutrition is a common condition in cancer patients which is usually associated with functional limitations, as well as increased morbidity and mortality. Based on the support of the young sections of Italian Association of Medical Oncology (AIOM), Italian Association of Radiotherapy and Clinical Oncology (AIRO) and Italian Society of Surgical Oncology (SICO) merged into the NutriOnc Research Group, we performed a multidisciplinary national survey with the aim to define the awareness of nutritional issues among healthcare professionals delivering anticancer care. The questionnaire was organized in four sections, as follows: Knowledge and practices regarding Nutritional Management of cancer patients; Timing of screening and assessment of Nutritional Status; Nutritional Treatment and prescription criteria; Immunonutrition and educational topics. The modules focused on esophagogastric, hepato-bilio-pancreatic and colorectal malignancies. Overall, 215 physicians completed the survey. As regards the management of Nutritional Status of cancer patients, many responders adopted the ERAS program (49.3%), while a consistent number of professionals did not follow a specific validated nutritional care protocol (41.8%), mainly due to lack of educational courses (14.5%) and financial support (15.3%). Nearly all the included institutions had a multidisciplinary team (92%) to finalize the treatment decision-making. Cancer patients routinely underwent nutritional screening according to 57.2% of interviewed physicians. The timing of nutritional assessment was at diagnosis (37.8%), before surgery (25.9%), after surgery (16.7%), before radiochemotherapy (13.5%) and after radiochemotherapy (7%). Most of the responders reported that nutritional status was assessed throughout the duration of cancer treatments (55.6%). An important gap between current delivery and need of nutritional assessment persists. The development of specific and defined care protocols and the adherence to these tools may be the key to improving nutritional support management in clinical practice