36 research outputs found
The high-power helicon program at DIII-D: gearing up for first experiments
Helicon current drive (CD), also called fast wave CD in the lower hybrid range of frequencies, has long been regarded as a promising CD tool for reactor grade plasmas. A newly installed MW-level system at DIII-D will be the first test of this technology in reactor-relevant plasmas, in the sense that full single-pass absorption is expected. A 30-module traveling wave antenna has been installed and optimized in-vessel in early 2020. The linear electromagnetic characteristics of the unloaded module array have been extensively tested both on the bench and in the vessel at instrumentation power levels. Excellent performance has been achieved, similar to 2% reflected power and similar to 1.5% dissipated power per module in air, in a 10 MHz band around 476 MHz. Stripline feeds on both ends of the antenna allow either co or counter CD. The installation of a 1.2 MW klystron and associated high-power electronics was completed in Fall 2020. Commissioning of the antenna is ongoing. An important goal of this experiment is to validate the helicon CD physics basis using an extensive set of new and upgraded diagnostics
Taxonomy of delays in the implementation of hospital computerized physician order entry and clinical decision support systems for prescribing:a longitudinal qualitative study
BACKGROUND: Implementation delays are common in health information technology (HIT) projects. In this paper, we sought to explore the reasons for delays in implementing major hospital-based HIT, through studying computerized physician order entry (CPOE) and clinical decision support (CDS) systems for prescribing and to develop a provisional taxonomy of causes of implementation delays. METHODS: We undertook a series of longitudinal, qualitative case studies to investigate the implementation and adoption of CPOE and CDS systems for prescribing in hospitals in the U.K. We used a combination of semi-structured interviews from six case study sites and two whole day expert roundtable discussions to collect data. Interviews were carried out with users, implementers and suppliers of CPOE/CDS systems. We used thematic analysis to examine the results, drawing on perspectives surrounding the biography of artefacts. RESULTS: We identified 15 major factors contributing to delays in implementation of CPOE and CDS systems. These were then categorized in a two-by-two delay classification matrix: one axis distinguishing tactical versus unintended causes of delay, and the second axis illustrating internal i.e., (the adopting hospital) versus external (i.e., suppliers, other hospitals, policymakers) related causes. CONCLUSIONS: Our taxonomy of delays in HIT implementation should enable system developers, implementers and policymakers to better plan and manage future implementations. More detailed planning at the outset, considering long-term strategies, sustained user engagement, and phased implementation approaches appeared to reduce the risks of delays. It should however be noted that whilst some delays are likely to be preventable, other delays cannot be easily avoided and taking steps to minimize these may negatively affect the longer-term use of the system
Treatment of primary advanced and recurrent endometrial carcinoma with a combination of carboplatin and paclitaxel
Treatment of primary advanced and recurrent endometrial carcinoma with a combination of carboplatin and paclitaxel - long-term follow-up
There is no generally accepted standard chemotherapy in treatment of advanced and recurrent endometrial carcinoma. Cisplatin and doxorubicin with or without cyclophosphamide are widely used. Response rates have improved with combination chemotherapy compared with single-agent therapy. A platinum analog seems to be an important part of the chemotherapy regimen. Since few patients are cured from their disease and since the duration of response is short, further improvement of this therapy is warranted. During the past years, the taxanes (paclitaxel) are being added to prior evaluated regimens and not only improved response rates are reported but also increased toxicity is observed. In a prospective, phase II, multicenter study, carboplatin (area under the curve = 5) and paclitaxel (175 mg/m(2)) were evaluated in treatment of primary advanced and recurrent endometrial carcinoma. In total, 66 patients were recruited during the years 2000-2004. Eighteen primary advanced tumors and 48 recurrences were treated. All histologic types and tumor grades were allowed. The median follow-up was 57 months (range 37-69 months). The overall response rate was 67% (95% CI 55-78). The complete response rate was 29% and the partial response rate 38%. Primary advanced and recurrent tumors as well as endometrioid and nonendometrioid tumors showed similar response rates. The median response duration was 14 months. The 1- and 3-year survival rates were 82% and 33%, respectively. The main toxicities were hematologic and neurologic (sensory neuropathy). The response rates were encouraging, superior to prior platinum-containing regimens, but response duration and the long-term survival rate were still short. The neurologic toxicity was frequent and was a substantial problem in this series of patients. Further research is highly needed to improve the treatment of advanced and recurrent endometrial cancer
Aflibercept (VEGF Trap) for advanced epithelial ovarian cancer (EOC) patients (pts) with symptomatic malignant ascites: Preliminary results of a pilot study
Remote operation of the DIII-D National Fusion Facility
Full remote scientific operation of the DIII-D National Fusion Facility is now possible through significant advances in the computer science hardware and software infrastructure made over the last decade. Capabilities around information visualization, data movement, and communication have all been enhanced. The level of capability deployed to remotely operate DIII-D required an infrastructure advancement over what had previously been achieved in the fusion community. The large quantity of real-time data that is automatically displayed on DIII-D’s control room screens can now be visualized by remote participants via web-based applications. New audio/video solutions using the VoIP and instant messaging application Discord have been implemented to mimic the dynamic and ad-hoc scientific conversations that are critical in successfully operating an experimental campaign. Discord’s ability for a user to rapidly move between audio channels, text with images, and share screens is a significant enhancement over traditional videoconferencing tools. In addition, multiple combinations of broadcast audio are made available via a web-based application to allow remote participants to simultaneously listen to general announcements/sounds while conducting their own specific conversations. Secure methodologies have been put into place to allow remote control of hardware including DIII-D’s plasma control system application. Secure methods also included the ability of the on-site team to closely coordinate their work with remote team members which has been enhanced through extensions to the wireless network and the use of tablet computers for audio/video/screen sharing. However, no amount of software can fully replace the need for ‘hands on hardware.’ This infrastructure was severely stress tested during the COVID-19 pandemic where occupancy of the DIII-D control room was restricted. Operational efficiency during the pandemic, measured in discharges per hour, remained high (3.8 ± 0.8) compared to values obtained pre-pandemic (3.7 ± 0.8)
