Contribution of auxetic core structures on the radial impact behaviour of 3D printed continuous fibre reinforced polyamid profiles

The present study investigates the enhanced energy absorption capabilities in the radial direction of structures through the combination of continuous glass fiber reinforced polyamide hollow sections (cGF/PA) and complex cellular cores manufactured by 3D printing cFF (continuous Fibre Fabrication). For this purpose, two types of auxetic structures based on conventional reentrant structure designs (hexagonal and octagonal) have been characterised. Likewise, the energy absorption capacity (SEA) of the filled profiles has been analysed and compared with the capability of the hollow profiles. Falling weight impact tests have been carried out for the dynamic characterization of the profiles and the effect of concentric fibers and the auxetic core on filled profiles has been analysed. On the one hand, it has been identified that the octagonal re-entrant structure (RSH) presents a higher impact performance, reaching a SEA value of 8.5 kJ/kg. On the other hand, it has been found a substantial improvement in the absorption capability of the filled profiles (17.7 kJ/kg) compared to the capability of the hollow profiles (2.5 kJ/kg). The SEA values achieved are promising, as they are 18% higher than the values found in literature

3D PRINTING OF BIO-INSPIRED CORES FOR OUT-OF-AUTOCLAVE SANDWICH STRUCTURES

The design and manufacture of sandwich structures allow for many variants related to core and skin types, but their fabrication is very limited with conventional technologies. Recent advances in 3D printing are creating new design possibilities, such as bio-inspired structures with more complex cellular units than the current ones, functional gradients, and curved panels. The present work has focused on two aspects; 1) the efficiency of the core inspired by the trabecular structure of beetle wings versus the conventional honeycomb, and 2) the feasibility of integrating these new cores with carbon fiber/epoxy prepreg skins for out-of-autoclave curing.  The results show that the ONYX® 3D printing cores obtained by filament extrusion technology and the skins manufactured by out-of-autoclave curing show good skin/core adhesion. On the other hand, the results of the flexural tests have shown that the stiffness of the sandwich panel with the trabecular structure is better than that of one of the honeycombs and the strength in both cases is similar. However, where substantial differences have been found between the two types of cores is in the quasi-static puncture resistance, that of the trabecular structure being 60% higher

Health-related quality of life of X-linked hypophosphatemia in Spain.

Health-related quality of life (HRQoL) of patients with X-linked hypophosphatemia (XLH) is lower than that of both the general population and the patients with other chronic diseases, mainly due to diagnostic delay, treatment difficulties, poor psychosocial support, and problems with social integration. Early diagnosis and optimal treatment are paramount to control the disease in patients with XLH, avoid complications, and maintain or improve their HRQoL. We, therefore, analyzed the HRQoL of pediatric and adult patients with XLH treated with conventional therapy in Spain. We used several versions of the EuroQol-5 dimensions (EQ-5D) instrument according to the age of patients with XLH. Then we compared the HRQoL of patients to that of the general Spanish population. Children with XLH (n = 21) had moderate problems in walking about (61.9%), washing or dressing themselves (9.52%), and performing their usual activities (33.33%). They also felt moderate pain or discomfort (61.9%) and were moderately anxious or depressed (23.81%). Adults with XLH (n = 29) had lower HRQoL, with problems in walking (93%, with 3.45% unable to walk independently), some level of pain (86%, with 3.45% experiencing extreme pain), problems with their usual activities (80%) and self-care (> 50%), and reported symptoms of anxiety and/or depression (65%). There were important differences with the general Spanish population. XLH impacts negatively on physical functioning and HRQoL of patients. In Spanish patients with XLH, the HRQoL was reduced despite conventional treatment, clearly indicating the need to improve the therapeutic approach to this disorder

Safety of hospital discharge before return of bowel function after elective colorectal surgery

Background: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function.Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system.Results: A total of 3288 patients were included in the analysis, of whom 301 (9.2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P < 0.001). There were no significant differences in rates of readmission between these groups (6.6 versus 8.0 per cent; P = 0.499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0.90, 95 per cent c.i. 0.55 to 1.46; P = 0.659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34.7 versus 39.5 per cent; major 3.3 versus 3.4 per cent; P = 0.110).Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients

Timing of nasogastric tube insertion and the risk of postoperative pneumonia: an international, prospective cohort study

Aim: Aspiration is a common cause of pneumonia in patients with postoperative ileus. Insertion of a nasogastric tube (NGT) is often performed, but this can be distressing. The aim of this study was to determine whether the timing of NGT insertion after surgery (before versus after vomiting) was associated with reduced rates of pneumonia in patients undergoing elective colorectal surgery. Method: This was a preplanned secondary analysis of a multicentre, prospective cohort study. Patients undergoing elective colorectal surgery between January 2018 and April 2018 were eligible. Those receiving a NGT were divided into three groups, based on the timing of the insertion: routine NGT (inserted at the time of surgery), prophylactic NGT (inserted after surgery but before vomiting) and reactive NGT (inserted after surgery and after vomiting). The primary outcome was the development of pneumonia within 30 days of surgery, which was compared between the prophylactic and reactive NGT groups using multivariable regression analysis. Results: A total of 4715 patients were included in the analysis and 1536 (32.6%) received a NGT. These were classified as routine in 926 (60.3%), reactive in 461 (30.0%) and prophylactic in 149 (9.7%). Two hundred patients (4.2%) developed pneumonia (no NGT 2.7%; routine NGT 5.2%; reactive NGT 10.6%; prophylactic NGT 11.4%). After adjustment for confounding factors, no significant difference in pneumonia rates was detected between the prophylactic and reactive NGT groups (odds ratio 1.03, 95% CI 0.56\u20131.87, P = 0.932). Conclusion: In patients who required the insertion of a NGT after surgery, prophylactic insertion was not associated with fewer cases of pneumonia within 30 days of surgery compared with reactive insertion

Timing of nasogastric tube insertion and the risk of postoperative pneumonia: an international, prospective cohort study

Aim: Aspiration is a common cause of pneumonia in patients with postoperative ileus. Insertion of a nasogastric tube (NGT) is often performed, but this can be distressing. The aim of this study was to determine whether the timing of NGT insertion after surgery (before versus after vomiting) was associated with reduced rates of pneumonia in patients undergoing elective colorectal surgery. Method: This was a preplanned secondary analysis of a multicentre, prospective cohort study. Patients undergoing elective colorectal surgery between January 2018 and April 2018 were eligible. Those receiving a NGT were divided into three groups, based on the timing of the insertion: routine NGT (inserted at the time of surgery), prophylactic NGT (inserted after surgery but before vomiting) and reactive NGT (inserted after surgery and after vomiting). The primary outcome was the development of pneumonia within 30 days of surgery, which was compared between the prophylactic and reactive NGT groups using multivariable regression analysis. Results: A total of 4715 patients were included in the analysis and 1536 (32.6%) received a NGT. These were classified as routine in 926 (60.3%), reactive in 461 (30.0%) and prophylactic in 149 (9.7%). Two hundred patients (4.2%) developed pneumonia (no NGT 2.7%; routine NGT 5.2%; reactive NGT 10.6%; prophylactic NGT 11.4%). After adjustment for confounding factors, no significant difference in pneumonia rates was detected between the prophylactic and reactive NGT groups (odds ratio 1.03, 95% CI 0.56–1.87, P = 0.932). Conclusion: In patients who required the insertion of a NGT after surgery, prophylactic insertion was not associated with fewer cases of pneumonia within 30 days of surgery compared with reactive insertion