ABSTRACT Objective: Identifying significant fibrosis is crucial to evaluate the prognosis and therapeutic interventions in patients with nonalcoholic fatty liver disease (NAFLD). We assessed the performance of acoustic radiation force impulse (ARFI) elastography, APRI, FIB-4, Forns, NFS and BARD scores in determining liver fibrosis in severe obesity. Subjects and methods: A prospective study included 108 patients undergoing bariatric surgery. Liver biopsy specimens were obtained intraoperatively and classified according to the NAFLD Activity Score. Patients were assessed with serological markers and shear wave velocity of the liver was measured with the Siemens S2000 ultrasound system preoperatively. Optimal cut-off values were determined using the area under the receiver operating characteristic curves (AUROC). Results: In the entire cohort prevalence of NAFLD was 80.6%, steatohepatitis 25.9% and significant fibrosis 19.4%. The best tests for predicting significant fibrosis were FIB-4 and Forns scores (both AUROC 0.78), followed by APRI (AUROC 0.74), NFS (AUROC 0.68), BARD (AUROC 0.64) and ARFI (AUROC 0.62). ARFI elastography was successful in 73% of the patients. Higher body mass index (BMI) correlated with invalid ARFI measurements. In patients with BMI < 42 kg/m2, ARFI showed 92.3% sensitivity and 82,6% specificity for the presence of significant fibrosis, with AUROC 0.86 and cut-off 1.32 m/s. Conclusions: FIB-4 and Forns scores were the most accurate for the prediction of significant fibrosis in bariatric patients. Applicability and accuracy of ARFI was limited in individuals with severe obesity. In patients with BMI < 42 kg/m2, ARFI elastography was capable for predicting significant fibrosis with relevant accuracy.

RESUMO Os objetivos da pesquisa foram produzir chapas de partículas com resíduos do processamento da madeira de Pinus elliottii coladas com resina poliuretana à base de mamona e avaliar o efeito da combinação da pressão e temperatura na qualidade das chapas produzidas. Para tanto, foram confeccionadas 12 chapas, subdivididas em quatro tratamentos em função da pressão (2,0; 3,0; 3,5; e 3,5 MPa) e temperatura (90; 90; 50; e 60 ºC). Depois de prensadas e climatizadas, as chapas foram seccionadas em corpos de prova, e realizados ensaios físico-mecânicos para determinação da densidade, inchamento e absorção de água (0-2h; 2-24h; e 0-24h); módulo de ruptura e de elasticidade em flexão estática, ligação interna e arrancamento de parafuso. As chapas prensadas com pressão de 3,0 MPa e temperatura de 90ºC e aquelas com pressão de 3,5 MPa e temperatura de 60ºC apresentaram os melhores resultados. A temperatura de prensagem foi a variável preponderante na qualidade das chapas produzidas.

ABSTRACT This work aimed to produce homogeneous layer particle boards with residues of Pinus elliottii wood adhered with polyurethane adhesive to castor oil plant base and to evaluate the effect of the combination of pressure and temperature in the quality of the particle boards produced. To do so, 12 particle boards were manufactured, subdivided into four treatments in function of the pressure (2.0; 3.0; 3.5; and 3.5 MPa) and temperature (90; 90; 50; and 60 ºC). The particleboards were sectioned in test samples, and accomplished by physical-mechanical tests for the determination of density, swelling and absorption of water (0-2h; 2-24h; and 0-24h); rupture module and elasticity module in static bending, internal ligation and screw withdrawal. The particle boards pressed with pressure of 3.0 MPa and temperature of 90 ºC and that with pressure of 3.5 MPa and temperature of 60 ºC presented the best results. The temperature of pressing was the predominant variable in the quality of those particle boards manufactured.