Hair loss is a common complication after metabolic and bariatric surgery (MBS). There is a lack of published systematic review in the scientific literature on this topic. The aim of this study was to perform a systematic review and meta-analysis on hair loss after MBS in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. PubMed, CINAHL, EMBASE, Web of Science, SCOPUS, and four Chinese databases were searched. Data were pooled using Review Manager 5.3 and Stata 12.0, and subgroups were performed if necessary and feasible. A total of 18 studies (n = 2538) were included. The pooled results showed that the incidence of hair loss after MBS was 57% (95% CI 42-71%). It decreased with longer follow-up times. Hair loss was significantly more common in younger (mean difference (MD), - 2.45; 95% CI, - 4.26 to - 0.64; p = 0.008) women (OR, 3.87; 95% CI, 0.59 to 17.59; p = 0.08). Serum zinc (standardized mean difference (SMD), - 1.13; 95% CI, - 2.27 to 0.01, p = 0.05), folic acid (SMD = - 0.88, 95% CI - 1.29 to - 0.46, p < 0.0001), and ferritin levels (SMD, - 0.22; 95% CI, - 0.38 to - 0.05; p = 0.01), but not serum iron and vitamin B , were associated with hair loss following MBS. Hair loss is common after MBS especially in younger women, and those with low serum levels of zinc, folic acid, and ferritin. Prospective studies on larger cohorts are needed. Hair loss is common after MBS especially in younger women, and those with low serum levels of zinc, folic acid, and ferritin. Prospective studies on larger cohorts are needed. Hundreds of thousands of patient-safety clinical incidents are reported to the National Reporting and Learning System (NRLS) database in England and Wales every year. The purpose of this study was to identify bariatric surgery-related learning points from these incidents. We analysed bariatric surgery-related clinical incidents reported to the NRLS database between 01 April 2005 and 31st October 2020. The authors used their experience to identify learning themes, attribute severity, and design a safety checklist from these reported incidents. We identified 541 bariatric surgery-related clinical incidents in 58 different themes. Preoperative, intraoperative, and postoperative incidents represented 30.3% (N = 164), 38.1% (N = 206), and 31.6% (N = 171) incidents respectively. One hundred fifty (27.7%), 244 (45.1%), and 147 (27.2%) incidents were attributed high, medium, and low severity respectively. The most commonly reported high severity theme was the failure of thromboprophylaxis (50; 9.2%). Intraoperative high severity incidents included 17 incidents of stapling of orogastric/nasogastric tubes or temperature probes, 8 missed needles, 8 broken graspers, and 6 incidents of band parts left behind. Postoperatively, the most commonly reported high severity theme was improper management of diabetes mellitus (DM) (35; 6.5%). Medication errors represented a significant proportion of the medium severity incidents. We identified 58 specific themes of bariatric surgery-related clinical incidents. We propose specific recommendations for the prevention of each theme and a safety checklist to help improve the safety of bariatric surgery worldwide. We identified 58 specific themes of bariatric surgery-related clinical incidents. We propose specific recommendations for the prevention of each theme and a safety checklist to help improve the safety of bariatric surgery worldwide. Cardiovascular engineering includes flows with fluid-dynamical stresses as a parameter of interest. Mechanical stresses are high-risk factors for blood damage and can be assessed by computational fluid dynamics. https://www.selleckchem.com/products/sb-204990.html By now, it is not described how to calculate an adequate scalar stress out of turbulent flow regimes when the whole share of turbulence is not resolved by the simulation method and how this impacts the stress calculation. We conducted direct numerical simulations (DNS) of test cases (a turbulent channel flow and the FDA nozzle) in order to access all scales of flow movement. After validation of both DNS with literature und experimental data using magnetic resonance imaging, the mechanical stress is calculated as a baseline. Afterwards, same flows are calculated using state-of-the-art turbulence models. The stresses are computed for every result using our definition of an equivalent scalar stress, which includes the influence from respective turbulence model, by using the parameter dissipation. Afterwards, the results are compared with the baseline data. The results show a good agreement regarding the computed stress. Even when no turbulence is resolved by the simulation method, the results agree well with DNS data. When the influence of non-resolved motion is neglected in the stress calculation, it is underpredicted in all cases. With the used scalar stress formulation, it is possible to include information about the turbulence of the flow into the mechanical stress calculation even when the used simulation method does not resolve any turbulence. With the used scalar stress formulation, it is possible to include information about the turbulence of the flow into the mechanical stress calculation even when the used simulation method does not resolve any turbulence. The Frozen Elephant Trunk (FET) stent is a hybrid endovascular device that may be implemented in the event of an aneurysm or aortic dissection of the aortic arch or superior descending aorta. A Type 1B endoleak can lead to intrasaccular flow during systole and has been identified as a known failure of the FET stent graft. The purpose was to develop in-vitro modelling techniques to enable the investigation of the known failure. A silicone aortic phantom and 3D printed surrogate stent graft were manufactured to investigate the haemodynamics of a Type 1B endoleak. Physiological pulsatile flow dynamics distal to the surrogate stent graft were investigated in-vitro using Particle Image Velocimetry (PIV). PIV captured recirculation zones and an endoleak distal to the surrogate stent graft. The endoleak was developed at the peak of systole and sustained until the onset of diastole. The endoleak was asymmetric, indicating a potential variation in the phantom artery wall thickness or stent alignment. Recirculation was identified on the posterior dorsal line during late systole.