Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Particulate Fillers in Thermoplastics

The characteristics of particulate filled thermoplastics are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape, while the main matrix property is stiffness. Segregation, aggregation and the orientation of anisotropic particles determine structure. Interfacial interactions lead to the formation of a stiff interphase considerably influencing properties. Interactions are changed by surface modification, which must be always system specific and selected according to its goal. Under the effect of external load inhomogeneous stress distribution develops around heterogeneities, which initiate local micromechanical deformation processes determining the macroscopic properties of the composites

Numerical And Experimental Modelling Of Two-dimensional Unsteady Heat Transfer During Inward Solidification Of Square Billets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The development of air gaps between the solidifying shell and the mould is an inherent phenomenon in both continuous and static casting processes, and is one of the major factors affecting not only the microstructure formation but also the resulting properties and surface quality of castings. The heat flux transients at the casting/mould interface therefore attracted many attempts of mathematical modelling. In this study, an explicitly solved unsteady-state two-dimensional finite difference heat transfer model was used for the solution of the inverse heat conduction problem. The overall heat transfer coefficient between the casting surface and the cooling fluid (h(g)) - which is affected by a series of thermal resistances such as those from water, mould and air gap formed between the metal surface and the inner mould surface - is determined for the inward solidification of a hypoeutectic Al-Fe alloy casting in a water-cooled steel mould. Thermocouples were inserted into the casting with a view to continuously measure temperatures during solidification, which is necessary to furnish thermal information to be compared with simulations, and an automatic search selected the best theoretical-experimental fit from a range of transient heat transfer coefficient profiles. The microstructural cellular spacing was measured in order to permit correlations with the cooling rate ((T)over dot) at different positions from the metal/mould interface to be established. It is shown by numerical heat transfer simulations that the cooling rate decreases from the casting surface, and after reaching a minimum value, starts to increase characterising a reversal trend towards the centre of the casting. It is also shown that the cellular spacing accompanies the trend in the cooling rate. The obtained results - transient (h(g)) profiles and growth laws relating the cellular spacing to () - can contribute to a better understanding of transport phenomena and microstructure evolution of more complex processes involving transient solidification. (C) 2016 Elsevier Ltd. All rights reserved.96454462FAPESP-Sao Paulo Research Foundation, Brazil [2012/08494-0, 2012/16328-2, 2013/23396-7]CNPq (The Brazilian Research Council)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

The effect of the growth rate on microsegregation: Experimental investigation in hypoeutectic Al-Fe and Al-Cu alloys directionally solidified

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Hypoeutectic Al-Cu and Al-Fe alloys were directionally solidified under unsteady-state heat flow conditions in a water-cooled solidification setup. The experimental cooling curves allowed solidification thermal parameters: tip cooling rate ((T) over dot) and tip growth rate (V-L) to be experimentally determined and correlated with the scale of the dendritic (Al-Cu alloys) and cellular (Al-Fe alloys) patterns. Experimental microsegregation profiles from the central part of the dendrite/cell cores to the limit of the interdendritic/intercellular regions were determined for different growth rates. The effect of the growth rate was incorporated into an effective partition coefficient that has been determined for the range of growth rates experimentally examined and both Scheil and Clyne-Kurz models were used in the prediction of microsegregation profiles. It was found that both models have significant deviations from the experimental data. Since the calculated results using the theoretical models yielded appreciable discrepancies from the experimental data, an experimental equation is proposed, showing a good agreement with the experimental data for the entire range of solid fractions and experimental tip growth rates, for any alloy experimentally examined. (C) 2013 Elsevier B.V. All rights reserved.561193200Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Laser remelting of Al-1.5 wt%Fe alloy surfaces: Numerical and experimental analyses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A 3D heat transfer mathematical model based on the finite element method is applied to the laser surface remelting (LSR) process with a view to simulating temperature fields and melt pool dimensions. The theoretical predictions furnished by the model are validated against LSR experimental results from tests carried out in the present study with Al-1.5 wt%Fe alloy samples. The work also encompasses an analysis of microstructural and microhardness variations throughout the resulting treated and untreated zones. A remarkable effect of the LSR treatment on the mechanical and corrosion resistance of the treated samples is shown. (C) 2011 Elsevier Ltd. All rights reserved.494490497Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAEPEX-UNICAMPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Idiopathic pulmonary haemosiderosis in a child with Down's syndrome: case report and review of the literature.

We report the case of a female child with Down's syndrome affected by idiopathic pulmonary haemosiderosis (IPH), who was successfully treated with hydroxychloroquine. First-line conventional treatment of IPH is traditionally based on systemic corticosteroids; however, many steroid-sparing agents are being increasingly used as adjuncts to corticosteroids in children with recurrent or refractory bleeding. The use of these drugs is particularly promising for maintenance treatment, because it tends to avoid the adverse effects of long-term corticosteroids