Single polymer composites (SPCs) based on polyamide 6 (PA6) were prepared by in-mold activated anionic ring-opening polymerization (AAROP) of caprolactam in the presence of PA6 textile fibers. The influence of the reinforcing fibers content, their surface treatment, as well as of the temperature of AAROP upon the morphology, crystalline structure, and mechanical properties of the resulting SPCs was followed. The presence of oriented transcrystalline layer (TCL) on the surface of the reinforcing fibers was demonstrated by means of microscopy methods. Its orientation and polymorph structure were determined by synchrotron wide-angle X-ray scattering. Studies on the mechanical behavior in tension of the SPCs showed a well-expressed growth of the stress at break (70-80 %) and deformation at break (up to 150-190 %) in composites with 15-20 wt% of reinforcements. The best mechanical properties were found in SPCs whose reinforcing fibers were solvent-pretreated prior to AAROP in order to remove the original finish. In these samples a stronger adhesion at the fiber/matrix interface was proved by scanning electron microscopy of cryofractured samples. This effect was related to a thinner TCL in which the α-to-γ polymorph transition is impeded.
In this work, a method for preparation of polyamide-6 (PA6) based laminates reinforced by glass fiber-(GFL) or polyamide-66 (PA66) textile structures (PL) via reactive injection molding is disclosed. It is based on in-mold anionic polymerization of e-caprolactam carried out at 165 C in the presence of the respective reinforcements performed in newly developed prototype equipment whose design concept and operation are described. Both composite types were produced for reaction times of 20 min, with conversion degrees of 97-99%. Initial mechanical tests in tension of GFL samples displayed almost twofold increase of the Young's modulus and stress at break values when compared with the neat anionic PA6. The improvement was proportional to the volume fraction V f of glass fiber fabric that was varied in the 0.16-0.25 range. A 300% growth of the impact strength was registered in PL composites with V f of PA66 textile of 0.1. Removing the surface finish of the latter was found to be a factor for improving the adhesion at the matrix-fiber interface. The mechanical behavior of GFL and PL composites was discussed in conjunction with the morphology of the samples studied by optical and electron microscopy and the matrix crystalline structure as revealed by synchrotron X-ray diffraction.
Purpose-The purpose of this paper is to examine the influence of structural empowerment, psychological empowerment and intrinsic motivation on perceived customer satisfaction in contact centers. Design/methodology/approach-A questionnaire was conducted among 703 employees of a contact center. Data analysis was based on structural equation modeling. Findings-Structural empowerment results in higher levels of perceived customer satisfaction through psychological empowerment and intrinsic motivation. Furthermore, structural empowerment effect on psychological empowerment is mediated by intrinsic motivation. Practical implications-Previous predictions regarding counterproductive impact of empowerment in a low-service heterogeneity sector, such as contact center are challenged and a transformative message is disclosed in what concerns human resource management (HRM) in contact centers. Originality/value-The research provides valuable insights for both scholars and practitioners regarding the process through which employees' psychological empowerment and intrinsic motivation improves customer satisfaction in the context of contact centers.
Background The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA). Methods The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up. Results The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien–Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013). Conclusion Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.
Background Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting. Methods Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.). Results Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome. Conclusion Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.
Background The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. Methods Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. Results Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). Conclusion Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.
Post-operative periodv Intensive care unit (ICU) v Hemodynamically stable v Hb 10 g/dL v HbS 18,4% v Sedo-Analgesia v Avoiding acidosis, hypoxia and hypovolemia v Hypocoagulation with warfarine, ursodeoxycholic acid, hydroxicobalamin and folic acid were initiated 15-year-old girl Prior medical history v Sick cell disease v Rheumatic valvulopathy (Mitral, tricuspid and aortic severe insufficiency)
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