13 research outputs found
LC oscillator chirp generator for LADAR applications
The design, layout, simulation, and testing of a signal generator integrated circuit (IC) intended to create a frequency modulated chirp signal used in Laser Assisted Detection and Ranging (LADAR) systems are described. LADAR systems function by illuminating a target with a laser beam and measuring the properties of the reflected signal. Applications include range finding, collision avoidance, terrain mapping, and facial recognition. The development and improvement of LADAR IC design can lead to miniaturized LADAR-on-chip systems that could significantly improve the usability and applications of said systems. Two designs, a fixed frequency oscillator bank (FFOB) and a voltage controlled oscillator bank (VCOB), were investigated as signal generators for chirped LADAR systems. The FFOB was designed to operate at 16 discrete frequencies ranging from 600 MHz to 2.1 GHz. The VCOB design offers a continuously variable frequency output ranging from 1 GHz to 3 GHz and outputs 32 discrete frequencies ranging from 1.5 GHz to 3.05 GHz in the suggested configuration. The FFOB design consists of 16 individual oscillators that are each controlled by a logical input pin on the package. In contrast, the VCOB design consists of eight oscillators, each with a tunable frequency and are cycled automatically by an on-chip digital counter circuit. All designs were completed in the IBM CMRF7SF process. The FFOB IC design was manufactured and packaged by MOSIS, and testing of the FFOB chip was completed. The VCOB IC was was designed to improve the performance of the FFOB signal generator by lowering power consumption, reducing signal distortion, increasing the number of the steps in the chirped waveform, and increasing bandwidth
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
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The Chicago Consensus on Peritoneal Surface Malignancies: Management of Colorectal Metastases
The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of colorectal cancer specifically as it relates to the management of peritoneal surface malignancy. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence
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The Chicago Consensus on Peritoneal Surface Malignancies: Management of Gastric Metastases
The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of gastric cancer specifically as it relates to the management of peritoneal surface malignancy. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness of the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence
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The Chicago Consensus on Peritoneal Surface Malignancies: Management of Peritoneal Mesothelioma
The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of peritoneal mesothelioma. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness of the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence
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The Chicago Consensus on Peritoneal Surface Malignancies: Management of Neuroendocrine Tumors
The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of neuroendocrine tumors specifically related to the management of peritoneal surface malignancy. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence
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The Chicago Consensus on Peritoneal Surface Malignancies: Management of Ovarian Neoplasms
The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of ovarian neoplasms specifically related to the management of peritoneal surface malignancy. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, gynecologic oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence
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The Chicago Consensus on Peritoneal Surface Malignancies: Standards
The Chicago Consensus Working Group provides the following multidisciplinary recommendations for the care of patients with peritoneal surface malignancies. This article focuses on the standards of a peritoneal surface malignancy center, standards of billing and coding, standards of operative reports for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, standards of cytoreductive surgery training, and standards of intraoperative chemotherapy preparation. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence
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The Chicago Consensus on Peritoneal Surface Malignancies: Palliative Care Considerations
The Chicago Consensus Working Group provides multidisciplinary recommendations for palliative care specifically related to peritoneal surface malignancies. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, gynecologic oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence