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Abstract Beam-to-column joints equipped with friction dampers are promising solutions to improve the performance of steel moment resisting frames due to the possibility to guarantee large dissipation capacity limiting the structural damage under severe seismic conditions. In this paper, the experimental tests and the numerical simulations of two types of joints are shown and discussed with the aim of developing pre-qualified configurations. The friction dampers are designed to be easily removable from both the lower beam flange and the column face by means of bolted connections. The devices are composed of a stack of steel plates conceived to assure symmetrical friction. The friction surface is set in vertical direction in first case and in horizontal direction in the second type. The experimental tests confirmed the effectiveness of both examined joints and the finite element analyses allowed characterizing their local response, thus providing additional insights to improve the design requirements. Highlights • The behavior of steel beam-to-column joints equipped with friction dampers is investigated. • Dampers with both horizontal and vertical friction surface are investigated. • Experimental tests on joints equipped with friction dampers show satisfactory response with negligible damage. • The tested joints show non-symmetric response under hogging and sagging moment. • Finite element simulations show that the vertical friction damper exhibit plastic deformations lower than the horizontal friction damper. [ABSTRACT FROM AUTHOR]

Abstract: An experimental study devoted to investigate the use of C-FRPs for repairing and strengthening lap shear hot-driven riveted connections is presented. Two set of tests were carried out: (i) double strap tests on both butt and lapped plates connected by C-FRP laminas; (ii) lap shear tests on riveted connections strengthened by C-FRP laminas. The efficacy of C-FRPs was assessed in terms of strength and ultimate displacement. An analytical model based on the component method for the prediction of the strengthened riveted connections was developed on the basis of the experimental outcomes. Finally, design criteria for the strengthening intervention based on the analytical and testing predictions are provided. [Copyright &y& Elsevier]

Abstract: Shear links are widely used in eccentric bracing of steel buildings and, recently, for seismic protection of existing bridges and buildings. Experimental tests carried out for classic eccentric bracing of steel buildings have consistently shown that peak inelastic shear forces up to 1.4–1.5 times the plastic shear strength can develop at plastic link rotations of about 0.08–0.1rad (plastic overstrength). However, more recent tests have shown that larger forces could be developed. Three basic parameters are devised as influencing shear overstrength: (i) axial forces acting on the link, (ii) the ratio of link flange over web area and (iii) the ratio between link length and cross section depth. In this paper only tensile axial forces induced by the presence of axial restraints and due to nonlinear geometric effects are dealt with. Numerical analysis of detailed finite element models has been carried out in order to ascertain the combined influence of these factors on the plastic overstrength of short links. A simple analytical model is proposed on the basis of finite element model analysis results. The analytical predictions are compared with the results of available experimental test results, showing good agreement. [Copyright &y& Elsevier]

Abstract: The results of an experimental study based on lap-shear tests on riveted connections are presented in this paper. Experimental specimens were manufactured with materials and techniques used in aged metal structures and different dimensions and configurations were considered. The results of the experimental investigation allowed the influence of various parameters on the response of the connections to be assessed, such as load eccentricity, variation in net area, plate width and number of rivets. The experimental results and predicted shear strengths were compared in order to evaluate the reliability of the provisions of EN 1993:1-8. On the basis of the results obtained, modifications are proposed to the design equations given by EN 1993:1-8 for the rivet shear strength and the ultimate resistance of the net cross-section. [Copyright &y& Elsevier]

Nudix hydrolase 7 (NUDT7) is an enzyme that hydrolyzes CoA species, is highly expressed in the liver, and resides in the peroxisomes. Peroxisomes are organelles where the preferential oxidation of dicarboxylic fatty acids occurs and where the hepatic synthesis of the primary bile acids cholic acid and chenodeoxycholic acid is completed. We previously showed that liver-specific overexpression of NUDT7 affects peroxisomal lipid metabolism but does not prevent the increase in total liver CoA levels that occurs during fasting. We generated Nudt7-/- mice to further characterize the role that peroxisomal (acyl-)CoA degradation plays in the modulation of the size and composition of the acyl-CoA pool and in the regulation of hepatic lipid metabolism. Here, we show that deletion of Nudt7 alters the composition of the hepatic acyl-CoA pool in mice fed a low-fat diet, but only in males fed a Western diet does the lack of NUDT7 activity increase total liver CoA levels. This effect is driven by the male-specific accumulation of mediumchain dicarboxylic acyl-CoAs, which are produced from the β-oxidation of dicarboxylic fatty acids. We also show that, under conditions of elevated synthesis of chenodeoxycholic acid derivatives, Nudt7 deletion promotes the production of tauromuricholic acid, decreasing the hydrophobicity index of the intestinal bile acid pool and increasing fecal cholesterol excretion in male mice. These findings reveal that NUDT7- mediated hydrolysis of acyl-CoA pathway intermediates in liver peroxisomes contributes to the regulation of dicarboxylic fatty acid metabolism and the composition of the bile acid pool. [ABSTRACT FROM AUTHOR]

Abstract The FRUVEDomics study investigates the effect of a diet intervention focused on increasing fruit and vegetable intake on the gut microbiome and cardiovascular health of young adults with/at risk for metabolic syndrome (MetS). It was hypothesized that the recommended diet would result in metabolic and gut microbiome changes. The 9-week dietary intervention adhered to the US Department of Agriculture Dietary Guidelines for Americans and focused on increasing fruit and vegetable intake to equal half of the diet. Seventeen eligible young adults with/or at high risk of MetS consented and completed preintervention and postintervention measurements, including anthropometric, body composition, cardiovascular, complete blood lipid panel, and collection of stool sample for microbial analysis. Participants attended weekly consultations to assess food logs, food receipts, and adherence to the diet. Following intention-to-treat guidelines, all 17 individuals were included in the dietary, clinical, and anthropometric analysis. Fruit and vegetable intake increased from 1.6 to 3.4 cups of fruits and vegetables (P <.001) daily. Total fiber (P =.02) and insoluble fiber (P <.0001) also increased. Clinical laboratory changes included an increase in sodium (P =.0006) and low-density lipoprotein cholesterol (P =.04). In the fecal microbiome, Erysipelotrichaceae (phylum Firmicutes) decreased (log2 fold change: −1.78, P =.01) and Caulobacteraceae (phylum Proteobacteria) increased (log2 fold change = 1.07, P =.01). Implementing a free-living 9-week diet, with intensive education and accountability, gave young adults at high risk for/or diagnosed with MetS the knowledge, skills, and feedback to improve diet. To yield greater impact, a longer diet intervention may be needed in this population. [ABSTRACT FROM AUTHOR]