Fatigue resistance of light alloy sheets undergoing eco-friendly chemical milling: metallurgical and chemical aspects

Abstract Component lightening is a key issue for automotive and aerospace industries. Lightening processes on design profile are not always possible by means of traditional machining processes. Then, chemical milling processes are used, often by acid etching. The effect on fatigue behavior is related on many factors, such as chemical surface composition and surface roughness. Material removal through chemical milling is in particular interesting for Additive manufactured components where surface finish still remains a parameter difficult to be controlled and repeated. The environmental aspects related to alkaline and acid processing are still an important issue. In the present paper, an overview on chemical milling for component lightening is presented with focus of the effects on mechanical and chemical resistance of materials. Then, the results of an experimental campaign on an aluminum alloy is presented. In particular, high cycle fatigue tests results are presented on specimens subjected or not subjected to an eco-friendly alkaline chemical milling process (called " Green Etching") and chemical, profilometric and metallographic analyses are presented and related to fatigue resistance results. Wettability and surface charge results will be presented

Three-dimensional minimally invasive video-assisted thyroidectomy: preliminary report

Three-dimensional (3D) minimally invasive video-assisted thyroidectomy (MIVAT) was carried out with a 4-mm, 3D 0-degree stereoscopic endoscope. The procedure was applied on 3 patients who underwent total thyroidectomy and data were prospectively collected. Operative time for total thyroidectomy ranged from 72 to 90 minutes. Neither intra-nor post-operative complications were reported during the study. The surgical team noticed a good perception of depth and easy recognising of anatomic structures, especially concerning the upper and lower vascular pedicle, the parathyroids, the superior and inferior laryngeal nerves. Preliminary impression emerging from this study seems to suggest that 3D MIVAT is safe and effective. Future studies with larger case series are required to determine the role of this procedure

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

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Problemi di storia dell'Internazionale comunista (1919-1939). Relazioni tenute al Seminario di studi organizzato dalla Fondazione Luigi Einaudi

Studi n. 1