Optimisation of A Novel Hot Air Contactless Single Incremental Point Forming of Polymers

This study presents a new contactless sheet forming method that utilises hot air as a forming tool to address tool wear challenges in single-point incremental forming. Experiments were conducted on a 3-axis CNC machine equipped with a hot air nozzle on a polycarbonate sheet. A design of experiment (DOE) approach was employed, evaluating five control factors: air pressure, air temperature, feed rate, tool offset, and step down. The evaluation criteria for the formed sheets are profile variation, thickness variation, and surface roughness. The results indicate that air temperature and feed rate have the most significant influence on the deformation process. Additionally, air pressure and feed rate substantially impact both thickness variation and surface roughness of the formed material. To optimise the process parameters for high-quality forming, a prediction model is developed. The optimised process shows good agreement with the predicted model regarding profile and thickness variations. However, it does not align with surface roughness due to the stepwise nature and inherent waviness of the contactless forming technique. This study offers a promising approach for developing innovative contactless forming techniques using hot pressurised air as a forming tool. The proposed technique has the potential to significantly reduce tool wear and lubrication requirements

Testing Flood Estimation Methods On Ancient Closed Conduits

Beside a large number of ancient tunnels in long-distance water conveyance systems toancient cities in Turkiye, five peculiar closed conduits, through which almost the entire discharge of water courses were flowing, are investigated. These are the Cevlik (Seleucia Pieria) tunnel inHatay province; vaulted structures covering the river bed in Bergama (Pergamon), in Sultanhisar(Nysa), in Acarlar near Ephesus (all four are leading examples of largest closed conduits from Roman times in the world); and the Bezirgan tunnel east of Kalkan, being an interesting example of emissary conduits draining the floods of closed basins. The hydraulic capacities of these conduits are determined; their corresponding flood return periods are estimated by four synthetic flood hydrograph methods. However, it was not possible to deduce any generalized conclusion based on the comparison of these results

Bright and Dark Soliton Solutions of the (2 + 1)-Dimensional Evolution Equations

In this paper, we obtained the 1-soliton solutions of the (2+1)-dimensional Boussinesq equation and the Camassa–Holm–KP equation. By using a solitary wave ansatz in the form of sechp function, we obtain exact bright soliton solutions and another wave ansatz in the form of tanhp function we obtain exact dark soliton solutions for these equations. The physical parameters in the soliton solutions are obtained nonlinear equations with constant coefficients

A numerical model for predicting powder characteristics in LMD considering particle interaction

In this work, a numerical model is proposed to analyze the influence of particle–particle interaction in laser directed energy deposition or LMD (laser metal deposition) of CM247 Ni-based superalloy. The model is based on the analysis of contact between particles and the potential agglomeration of powder to predict powder conditions at the nozzle exit. Simulation results were experimentally validated and a good agreement was observed. At the nozzle exit mainly large particles (>100 lm) are found and small ones (<10 lm) tend to flow away from this region. This was also observed in the experimental PSD. Additionally, based on the relative velocity of particles, simulations are able to predict the formation of dents. In comparing virgin powder PSD and the one at the nozzle exit, it was observed that largest particles are collected at the exit. In order to explain this phenomena, particle agglomeration was analysed numerically. It was seen that small particles tend to adhere to the big ones due to their higher adhesive forces, which would explain the change in PSD

A simplified acute kidney injury predictor following transcatheter aortic valve implantation: ACEF score

Background: Transcatheter aortic valve implantation (TAVI) is an effective, less invasive treatment alternative for symptomatic severe aortic stenosis (AS). Acute kidney injury (AKI) following TAVI is a common complication and is associated with worse outcomes. The age, creatinine, ejection fraction (ACEF) score is a simple scoring method, including only three parameters: age, creatinine, and ejection fraction (EF). The score was well established in predicting AKI after coronary interventions.Aims: We aimed to evaluate whether this simple scoring method, ACEF, may predict a development of AKI in patients who underwent TAVI.Methods: A total of 173 consecutive patients with symptomatic severe AS who underwent TAVI were included retrospectively. The primary endpoint of the study was the development of AKI. Study population was divided into two groups according to the presence of AKI. The ACEF score was calculated with the formula: age/EF + 1 (if baseline creatinine &gt;2 mg/dl).Results: Twenty-nine patients developed AKI. The median (interquartile range) ACEF score was 1.36 (1.20–1.58). The ACEF score was found to be an independent predictor of AKI (P &lt;0.001). The ACEF score ≥1.36 predicted AKI development with a sensitivity of 96.6% and specificity of 58.8%. Moreover, hypertension, hemoglobin levels, contrast volume, and aortic valve area (AVA) were found to be independent predictors of AKI.Conclusions: Our study revealed that the ACEF score was an independent predictor of AKI. A simple and objective score might be very useful in predicting AKI development in patients undergoing TAVI

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6&nbsp;years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P &lt; 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100&nbsp;years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely