43 research outputs found

    Modulation of Pore Shape and Adsorption Selectivity by Ligand Functionalization in a Series of “rob”-like Flexible Metal-Organic Frameworks

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    We report the synthesis of a new family of four new isoreticular metal–organic frameworks (MOFs) based on Cu–Cu paddle-wheel building units. The four MOFs contain 1D microchannels modulated by chemical functionalisation of a dicarboxylate ligand or the use of different bis-4,40-pyridyl-like connectors behaving as ancillary linkers. A deep analysis of their CO2, H2 and CH4 adsorption properties, combining both experimental and grand canonical Monte Carlo isotherms as well as in situ synchrotron X-ray diffraction, shows variable adsorption behaviour towards the studied gases, with some materials acting as molecular sieves with virtually infinite selectivity.This work was supported by the Junta de Andalucía (FQM-1484), Red Guipuzcoana de Ciencia, Tecnolgía e Innovación (OF188/2017) and University of the Basque Country (GIU14/01, GIU17/013, EHUA16/32). The authors acknowledge technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF). D. F.-J. thanks the Royal Society for funding through a University Research Fellowship and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (NanoMOFdeli), ERC-2016-COG 726380

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    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

    Epitaxial silicon devices for dosimetry applications

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    A straightforward improvement of the efficiency and long term stability of silicon dosimeters has been obtained with a n+/p junction surrounded by a guard-ring structure implanted on an epitaxial p-type Si layer grown on a Czochralski substrate. The sensitivity of devices made on 50um-thick epitaxial Si degrades by only 7% after an irradiation with 6 MeV electrons up to 1.5 kGy, and shows no significant further decay up to 10 kGy. These results prove the enhanced radiation tolerance and stability of epitaxial diodes as compared to present state-of-the-art Si devices
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