43 research outputs found

    Multi-level parallel clocking of CCDs for: improving charge transfer efficiency, clearing persistence, clocked anti-blooming, and generating low-noise backgrounds for pumping

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    A multi-level clocking scheme has been developed to improve the parallel CTE of four-phase CCDs by suppressing the effects of traps located in the transport channel under barrier phases by inverting one of these phases throughout the transfer sequence. In parallel it was apparent that persistence following optical overload in Euclid VIS detectors would lead to undesirable signal released in subsequent rows and frames and that a suitable scheme for flushing this signal would be required. With care, the negatively biased electrodes during the multi-level transfer sequence can be made to pin the entire surface, row-by-row, and annihilate the problematic charges. This process can also be extended for use during integration to significantly reduce the unusable area of the detector, as per the clocked anti-blooming techniques developed many years ago; however, with the four-phase electrodes architecture of modern CCDs, we can take precautionary measures to avoid the problem of charge pumping and clock induced charge within the science frames. Clock induced charge is not all bad! We also propose the use of on-orbit trap-pumping for Euclid VIS to provide calibration input to ground based correction algorithms and as such a uniform, low noise background is require. Clock induced charge can be manipulated to provide a very suitable, low signal and noise background to the imaging array. Here we describe and present results of multi-level parallel clocking schemes for use in four-phase CCDs that could improve performance of high precision astronomy applications such as Euclid VIS

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Interpreting Statutes

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    Book review

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