99 research outputs found
Experimental characterization of a Polymer Metal Hybrid (PMH) automotive structure under quasi-static, creep, and impact loading
A feasibility study on a short fibre reinforced Polymer Metal Hybrid (PMH) solution of a car’s suspension control arm has been conducted through a simplified demonstrator, representative of the most critical portion of this component. It was injection moulded in two versions: an all composite one and a PMH version, in which the short fibre reinforced composite was over-moulded on to an aluminium insert. The demonstrator underwent quasi- static, creep and impact tests to simulate most of the loading conditions experienced by a suspension arm during its lifetime. The mechanical behaviours of the two demonstrator versions were compared to highlight the differences introduced by the proposed novel PMH solution. In particular, the ductile metal insert ensured the compliance of the PMH demonstrators with the automotive specific safety requirement of avoiding the complete separation at failure, which was successfully obtained in all testing conditions
A simple echocardiographic score to rule out cardiac amyloidosis
BACKGROUND: Early diagnosis of cardiac amyloidosis (CA) is warranted to initiate specific treatment and improve outcome. The amyloid light chain (AL) and inferior wall thickness (IWT) scores have been proposed to assess patients referred by hematologists or with unexplained left ventricular (LV) hypertrophy, respectively. These scores are composed of 4 or 5 variables, respectively, including strain data. METHODS: Based on 2 variables common to the AL and IWT scores, we defined a simple score named AMYLoidosis Index (AMYLI) as the product of relative wall thickness (RWT) and E/e' ratio, and assessed its diagnostic performance. RESULTS: In the original cohort (n=251), CA was ultimately diagnosed in 111 patients (44%). The 2.22 value was selected as rule-out cut-off (negative likelihood ratio [LR-] 0.0). In the hematology subset, AL CA was diagnosed in 32 patients (48%), with 2.36 as rule-out cut-off (LR- 0.0). In the hypertrophy subset, ATTR CA was diagnosed in 79 patients (43%), with 2.22 as the best rule-out cut-off (LR- 0.0). In the validation cohort (n=691), the same cut-offs proved effective: indeed, there were no patients with CA in the whole population or in the hematology or hypertrophy subsets scoring <2.22, <2.36 or <2.22, respectively. CONCLUSIONS: The AMYLI score (RWT* E/e') may have a role as an initial screening tool for CA. A <2.22 value excludes the diagnosis in patients undergoing a diagnostic screening for CA, while a <2.36 and a <2.22 value may be better considered in the subsets with suspected cardiac AL amyloidosis or unexplained hypertrophy, respectively
Multiparametric Echocardiography Scores for the Diagnosis of Cardiac Amyloidosis
OBJECTIVES: This study aimed to investigate the accuracy of a broad range of echocardiographic variables to develop multiparametric scores to diagnose CA in patients with proven light chain (AL) amyloidosis or those with increased heart wall thickness who had amyloid was suspected. We also aimed to further characterize the structural and functional changes associated with amyloid infiltration. BACKGROUND: Cardiac amyloidosis (CA) is a serious but increasingly treatable cause of heart failure. Diagnosis is challenging and frequently unclear at echocardiography, which remains the most often used imaging tool. METHODS: We studied 1,187 consecutive patients evaluated at 3 referral centers for CA and analyzed morphological, functional, and strain-derived echocardiogram parameters with the aim of developing a score-based diagnostic algorithm. Cardiac amyloid burden was quantified by using extracellular volume measurements at cardiac magnetic resonance. RESULTS: A total of 332 patients were diagnosed with AL amyloidosis and 339 patients with transthyretin CA. Concentric remodeling and strain-derived parameters displayed the best diagnostic performance. A multivariable logistic regression model incorporating relative wall thickness, E wave/e' wave ratio, longitudinal strain, and tricuspid annular plane systolic excursion had the greatest diagnostic performance in AL amyloidosis (area under the curve: 0.90; 95% confidence interval: 0.87 to 0.92), whereas the addition of septal apical-to-base ratio yielded the best diagnostic accuracy in the increased heart wall thickness group (area under the curve: 0.80; 95% confidence interval: 0.85 to 0.90). CONCLUSIONS: Specific functional and structural parameters characterize different burdens of CA deposition with different diagnostic performances and enable the definition of 2 scores that are sensitive and specific tools with which diagnose or exclude CA
Permanent draft genome sequences of the symbiotic nitrogen fixing Ensifer meliloti strains BO21CC and AK58
Ensifer (syn. Sinorhizobium) meliloti is an important symbiotic bacterial species that fixes nitrogen. Strains BO21CC and AK58 were previously investigated for their substrate utilization and their plant-growth promoting abilities showing interesting features. Here, we describe the complete genome sequence and annotation of these strains. BO21CC and AK58 genomes are 6,985,065 and 6,974,333 bp long with 6,746 and 6,992 genes predicted, respectively. © retained by original authors
A model of management academics' intentions to influence values
Business schools face increased criticism for failing in the teaching of management studies to nurture their students’ values. Assuming that individual academics play an important role in shaping the value-related influence of business schools, I model management academics’ intentions to influence values. The suggested model encompasses academics’ economic and social values as internal variables, as well as perceived support for attempting to influence values and academic tenure as social and structural variables. A test with empirical data from 1,254 management academics worldwide reveals that perceived external support is most relevant for explaining intentions. Moreover, academics’ social values, but not their economic ones, contribute to an explanation of their intentions to influence values. The results reveal how important it is for academics to believe that their colleagues, higher education institutions, and other stakeholders support their value-related behavioral intentions
Economics education and value change: The role of program-normative homogeneity and peer influence
In the light of corporate scandals and the recent financial crisis, there has been an increased interest in the impact of business education on the value orientations of graduates. Yet our understanding of how students' values change during their time at business school is limited. In this study,weinvestigate the effects of variations in the normative orientations of economics programs. We argue that interaction among economics students constitutes a key mechanism of value socialization, the effects of which are likely to vary across more-or-less normatively homogeneous economics programs. In normatively homogeneous programs, students are particularly likely to adopt economics values as a result of peer interaction. We specifically explore changes in power, hedonism, and self-direction values in a 2-year longitudinal study of economics students (N 5 197) in a normatively homogeneous and two normatively heterogeneous economics programs. As expected, for students in a normatively homogeneous economics program, interaction with peers was linked with an increase in power and hedonism values, and a decrease in self-direction values. Our findings highlight the interplay between program normative homogeneity and peer interaction as an important factor in value socialization during economics education and have important practical implications for business school leaders
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