Project MoonDust: Characterization and Mitigation of Lunar Dust

The feasibility of extended exploration and human presence on the Moon and Mars depends critically on dealing with the environmental factors, especially the intrusive effects of dust. The prior Apollo landed missions found that the lunar dust exhibited high adherence to exposed surfaces and a restrictive friction-like action causing premature wear of the EVA suits. MoonDust is a project being performed in collaboration with the Canadian Space Agency to study the effects of lunar dust on optics and mechanics, and to develop innovative solutions to extend their operational lifetime within a lunar or Mars environment based on the unique properties of carbon nanotube (CNT) nanocomposites. To assist this work, a small lunar environment simulation vacuum chamber has been set-up at MPB Communications to enable the study of lunar dust effects on optics and rotary mechanisms at pressures to below 10-5 Torr. New lunar dust simulants have been developed at the University of Winnipeg, characteristic of lunar Mare (UW-M1) and highland (UW-H1) compositions, that incorporate nanophase Fe in the silica particles. This paper describes the preliminary characterization of the various available lunar dust simulants that has included IR Raman for composition, Atomic Force and SEM Microscopy for morphology, and Vibrating Sample Magnetometer (VSM) for magnetic properties. Trial CNT dust deflectors/traps were fabricated and experimentally validated for magnetic and electrostatic interactions with lunar dust simulants. Good deflection and retention of submicron dust particles for device dust protection was observed. The preliminary experimental results are discussed

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

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

Lecturas francesas de Unamuno: Sénancour

[ES] Artículo que trata sobre la influencia de la obra del escritor francés Étienne Pivert de Sénancour en Miguel de Unamuno. Unamuno cita numerosas veces a Sénancour, especialmente por su obra "Obermann".[EN] Article which deals with the influence of the work of French writer Etienne Pivert of Sénancour in Miguel de Unamuno. Unamuno Sénancour cites numerous times, especially for his work "Obermann.

Estudo da actividade catalítica de complexos quirais de ácidos de Lewis na reacção de Diels-Alder entre acrilato de metilo e ciclopentadieno

Estèbe , Fohlen Claude, Godechot Jacques, Guiral Pierre, Martel André, Meyer Jean, Rey-Goldzeiger Annie, Roche Anne, Sagave Pierre-Paul, Témime Emile, Vigier , Wright , Zeldin Théodore. Extraits de la discussion générale du Colloque d'historiographie. In: Revue d’histoire moderne et contemporaine, tome 21 N°1, Janvier-mars 1974. L'historiographie du Second Empire. pp. 181-185

Project Moondust: Characterization and mitigation of lunar dust

The feasibility of extended exploration and human presence on the Moon and Mars depends critically on dealing with the environmental factors, especially the intrusive effects of dust. The prior Apollo landed missions found that the lunar dust exhibited high adherence to exposed surfaces and a restrictive friction-like action causing premature wear of the EVA suits. MoonDust is a project being performed in collaboration with the Canadian Space Agency to study the effects of lunar dust on optics and mechanics, and to develop innovative solutions to extend their operational lifetime within a lunar or Mars environment based on the unique properties of carbon nanotube (CNT) nanocomposites. To assist this work, a small lunar environment simulation vacuum chamber has been set-up at MPB Communications to enable the study of lunar dust effects on optics and rotary mechanisms at pressures to below 10-5 Torr. New lunar dust simulants have been developed at the University of Winnipeg, characteristic of lunar Mare (UW-M1) and highland (UW-H1) compositions, which incorporate nanophase Fe in the silica particles. This paper describes the preliminary characterization of the various available lunar dust simulants that has included IR Raman and EDX for molecular an