12 research outputs found

    Ballistic performance of thermoplastic composite laminates made from aramid woven fabric and polypropylene matrix

    Get PDF
    The ballistic behavior of multi-layer Kevlar (R) aramid fabric/polypropylene (PP) composite laminate (CL) and plain layered aramid fabric (AF) impact specimens was investigated. It was found that the thermoplastic PP matrix increases the ballistic performance of CL targets when compared to AF targets with similar areal density, resulting in less aramid fabric needed to obtain the same level of protection when the PP matrix is incorporated. It was found that the improved ballistic performance of CL targets is due to the fact that the thermoplastic matrix enables energy absorbing mechanisms such as fabric/matrix debonding and delamination. The ballistic limit and penetration threshold energy of the CL configurations, which were predicted using an empirical model, were found to be higher than those of the AF targets. These results show that aramid fabric/PP laminates should be further studied for improved ballistic performance at lower costs. (C) 2012 Elsevier Ltd. All rights reserved

    Photoelastic evaluation of fiber surface-treatments on the interfacial performance of a polyester fiber/epoxy model composite

    Get PDF
    The interfacial adhesion between a polyester fiber and an epoxy matrix was improved by chemical and topological modifications of the fiber surface. The maximum interfacial shear strength was measured using photoelasticity to assess the interfacial performance in pull-out single-fiber composite specimens. An increase of the interfacial shear strength was observed when plasma-treated or surface-modified fibers were used: also, as the applied load to the free fiber was increased, the fiber treatment caused a reduction of the debonded area at the fiber-matrix interface. (C) 2011 Elsevier Ltd. All rights reserved

    Microbial community engineering for biopolymer production from glycerol

    No full text
    In this work, the potential of using microbial community engineering for production of polyhydroxyalkanoates (PHA) from glycerol was explored. Crude glycerol is a by-product of the biofuel (biodiesel and bioethanol) industry and potentially a good substrate for bioplastic production. A PHA-producing microbial community was enriched based on cultivation in a feast–famine regime as successfully applied before for fatty acids-based biopolymer production. A glycerol-fed sequencing batch reactor operated at a 2-day liquid and biomass residence time and with feast–famine cycles of 24 h was used to enrich a mixed community of PHA producers. In a subsequent fedbatch PHA production step under growth-limiting conditions, the enriched mixed community produced PHA up to a dry weight content of 80 wt.%. The conversion efficiency of substrate to PHA on electron basis was 53%. Since glycerol is entering the metabolic pathways of the cell in the glycolytic pathway, it was anticipated that besides PHA, polyglucose could be formed as storage polymer as well. Indeed, polyglucose was produced in low amounts (~10 wt.%). The results indicated that the feast–famine-based enrichment strategy was comparably successful to obtain a microbial community compared to fatty acids-based enrichment described before.BT/BiotechnologyApplied Science

    Next-generation ARIA care pathways for rhinitis and asthma: a model for multimorbid chronic diseases

    No full text
    Abstract Background In all societies, the burden and cost of allergic and chronic respiratory diseases are increasing rapidly. Most economies are struggling to deliver modern health care effectively. There is a need to support the transformation of the health care system into integrated care with organizational health literacy. Main body As an example for chronic disease care, MASK (Mobile Airways Sentinel NetworK), a new project of the ARIA (Allergic Rhinitis and its Impact on Asthma) initiative, and POLLAR (Impact of Air POLLution on Asthma and Rhinitis, EIT Health), in collaboration with professional and patient organizations in the field of allergy and airway diseases, are proposing real-life ICPs centred around the patient with rhinitis, and using mHealth to monitor environmental exposure. Three aspects of care pathways are being developed: (i) Patient participation, health literacy and self-care through technology-assisted “patient activation”, (ii) Implementation of care pathways by pharmacists and (iii) Next-generation guidelines assessing the recommendations of GRADE guidelines in rhinitis and asthma using real-world evidence (RWE) obtained through mobile technology. The EU and global political agendas are of great importance in supporting the digital transformation of health and care, and MASK has been recognized by DG Santé as a Good Practice in the field of digitally-enabled, integrated, person-centred care. Conclusion In 20 years, ARIA has considerably evolved from the first multimorbidity guideline in respiratory diseases to the digital transformation of health and care with a strong political involvement

    Next-generation ARIA care pathways for rhinitis and asthma: a model for multimorbid chronic diseases

    No full text
    Abstract Background In all societies, the burden and cost of allergic and chronic respiratory diseases are increasing rapidly. Most economies are struggling to deliver modern health care effectively. There is a need to support the transformation of the health care system into integrated care with organizational health literacy. Main body As an example for chronic disease care, MASK (Mobile Airways Sentinel NetworK), a new project of the ARIA (Allergic Rhinitis and its Impact on Asthma) initiative, and POLLAR (Impact of Air POLLution on Asthma and Rhinitis, EIT Health), in collaboration with professional and patient organizations in the field of allergy and airway diseases, are proposing real-life ICPs centred around the patient with rhinitis, and using mHealth to monitor environmental exposure. Three aspects of care pathways are being developed: (i) Patient participation, health literacy and self-care through technology-assisted “patient activation”, (ii) Implementation of care pathways by pharmacists and (iii) Next-generation guidelines assessing the recommendations of GRADE guidelines in rhinitis and asthma using real-world evidence (RWE) obtained through mobile technology. The EU and global political agendas are of great importance in supporting the digital transformation of health and care, and MASK has been recognized by DG Santé as a Good Practice in the field of digitally-enabled, integrated, person-centred care. Conclusion In 20 years, ARIA has considerably evolved from the first multimorbidity guideline in respiratory diseases to the digital transformation of health and care with a strong political involvement

    Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

    Get PDF
    Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally

    The surgical safety checklist and patient outcomes after surgery: a prospective observational cohort study, systematic review and meta-analysis

    Get PDF
    © 2017 British Journal of Anaesthesia Background: The surgical safety checklist is widely used to improve the quality of perioperative care. However, clinicians continue to debate the clinical effectiveness of this tool. Methods: Prospective analysis of data from the International Surgical Outcomes Study (ISOS), an international observational study of elective in-patient surgery, accompanied by a systematic review and meta-analysis of published literature. The exposure was surgical safety checklist use. The primary outcome was in-hospital mortality and the secondary outcome was postoperative complications. In the ISOS cohort, a multivariable multi-level generalized linear model was used to test associations. To further contextualise these findings, we included the results from the ISOS cohort in a meta-analysis. Results are reported as odds ratios (OR) with 95% confidence intervals. Results: We included 44 814 patients from 497 hospitals in 27 countries in the ISOS analysis. There were 40 245 (89.8%) patients exposed to the checklist, whilst 7508 (16.8%) sustained ≥1 postoperative complications and 207 (0.5%) died before hospital discharge. Checklist exposure was associated with reduced mortality [odds ratio (OR) 0.49 (0.32–0.77); P\u3c0.01], but no difference in complication rates [OR 1.02 (0.88–1.19); P=0.75]. In a systematic review, we screened 3732 records and identified 11 eligible studies of 453 292 patients including the ISOS cohort. Checklist exposure was associated with both reduced postoperative mortality [OR 0.75 (0.62–0.92); P\u3c0.01; I2=87%] and reduced complication rates [OR 0.73 (0.61–0.88); P\u3c0.01; I2=89%). Conclusions: Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine

    Critical care admission following elective surgery was not associated with survival benefit: prospective analysis of data from 27 countries

    Get PDF
    This was an investigator initiated study funded by Nestle Health Sciences through an unrestricted research grant, and by a National Institute for Health Research (UK) Professorship held by RP. The study was sponsored by Queen Mary University of London
    corecore