Comportement mécanique d'un enduit projeté sur son support pour la réhabilitation thermique des bâtiments - expérimentations à l'échelle d'un mur

International audienceCette étude traite du comportement mécanique d'une solution d'isolation par l'extérieur pour la réhabilitation thermiquedes bâtiments. L'étude présentée est réalisée à l'échelle d'un volume élémentaire représentatif (V.E.R.) de mur. La solutiond'isolation est constituée d'un enduit présentant de meilleures performances thermiques que les isolants les plus efficaces se trouvant sur le marché actuellement. Il est appliqué par projection d'une couche de 4 cm d'épaisseur sur la surface extérieure d'une structure. Ce matériau est réalisé à partir de l'aérogel de silice. Sa composition en fait un matériau poreux avec une faible résistance mécanique ainsi qu'un faible module d'Young, en comparaison d'enduits classiques. Par conséquent, le comportement mécanique de l'association structure/enduit est peu prédictible. Ce papier concerne l'étude expérimentale d'un mur maçonné recouvert de cette solution d'isolation et soumis à des sollicitations de cisaillement dans son plan. Parmi les phénomènes à approfondir, il y a une meilleure connaissance de la fissuration de l'enduit et le décollement par rapport à son support. La technique de corrélation d'images a été utilisée pour obtenir un champ de déplacement.</p

Polarization-Engineering in III-V Nitride Heterostructures: New Opportunities For Device Design

The role of spontaneous and piezoelectric polarization in III-V nitride heterostructure devices is discussed. Problems as well as opportunities in incorporating polarization in abrupt and graded heterojunctions composed of binary, ternary, and quaternary nitrides are outlined.Comment: 7 pages, 5 figure

Clinical Utility of D-Dimer for Rule-Out or Rule-In of Venous Thromboembolism in Syncope

Fig. 1 Diagnostic performance of D-dimer using two different assays in patients presenting with syncope. A Left: Receiver-operating characteristic curves quantifying the diagnostic performance of Innovance® D-dimer (blue) and hs-Loci-Innovance® D-dimer (red) for the diagnosis of venous thromboembolism (VTE). Right: Clinical application of D-dimer using the 2-level Wells-score with age-adjusted1 or fixed cutoffs versus the YEARS-algorithm with probability-adjusted cut offs2. B Left: Specificity for different cufoffs of Innovance® D-dimer (blue) and hs-Loci-Innovance® D-dimer (red) for the diagnosis of venous thromboembolism (VTE). Right: Percentage of patients ruled-in and correctly identified VTE patients for different cutoffs of Innovance® D-dimer (blue) and hs-Loci-Innovance® D-dimer (red). 1In patients 50 years or younger, D-dimer concentration < 0.5 mg/l was considered negative. For patients older than 50 years, we used the formula: age in years divided by 100. 2YEARS-algorithm: assessment of only three items from the Wells-score (clinical signs of deep vein thrombosis, hemoptysis, pulmonary embolism the most likely diagnosis) and using a D-dimer test threshold of 0.5 mg/l in presence, and 1.0 mg/l in absence of one of the YEARS-items. Keywords: Diagnostic testing; Pulmonary embolism; Syncop

Absence of cardiotrophin 1 is associated with decreased age-dependent arterial stiffness and increased longevity in mice

Cardiotrophin 1 (CT-1), an interleukin 6 family member, promotes fibrosis and arterial stiffness. We hypothesized that the absence of CT-1 influences arterial fibrosis and stiffness, senescence, and life span. In senescent 29-month- old mice, vascular function was analyzed by echotracking device. Arterial histomorphology, senescence, metabolic, inflammatory, and oxidative stress parameters were measured by immunohistochemistry, reverse transcription polymerase chain reaction, Western blot, and ELISA. Survival rate of wild-type and CT-1–null mice was studied. Vascular smooth muscle cells were treated with CT-1 (10 −9 mol/L) for 15 days to analyze senescence. The wall stress-incremental elastic modulus curve of old CT-1–null mice was shifted rightward as compared with wild-type mice, indicating decreased arterial stiffness. Media thickness and wall fibrosis were lower in CT-1–null mice. CT-1–null mice showed decreased levels of inflammatory, apoptotic, and senescence pathways, whereas telomere-linked proteins, DNA repair proteins, and antioxidant enzyme activities were increased. CT-1–null mice displayed a 5-month increased median longevity compared with wild-type mice. In vascular smooth muscle cells, chronic CT-1 stimulation upregulated apoptotic and senescence markers and downregulated telomere-linked proteins. The absence of CT-1 is associated with decreased arterial fibrosis, stiffness, and senescence and increased longevity in mice likely through downregulating apoptotic, senescence, and inflammatory pathways. CT-1 may be a major regulator of arterial stiffness with a major impact on the aging proces

Echocardiographic diastolic function evolution in patients with an anterior Q-wave myocardial infarction: insights from the REVE-2 study.

International audienceBackground: Myocardial fibrosis plays a key role in the development of adverse left ventricular remodeling after myocardial infarction (MI). This study aimed to determine whether the circulating levels of BNP, collagen peptides, and galectin-3 are associated with diastolic function evolution (both deterioration and improvement) at 1-year after an anterior MI.Methods: The REVE-2 is a prospective multicenter study including 246 patients with a first anterior Q-wave MI. Echocardiographic assessment was performed at hospital discharge and ±1-year after MI. BNP, Galectin-3 and collagen peptides were measured ±1-month after MI. Left ventricular diastolic dysfunction (DD) was defined according to the presence of at least 2 criteria of echocardiographic parameters: septal e’6 mg/l (Odds Ratio, OR=5.29; 95%CI=1.05-26.66; p=0.044), Galectin-3>13 μg/l (OR=5.99; 95%CI=1.18-30.45; p=0.031), and BNP>82 ng/l (OR=10.25; 95%CI=2.36-44.50; p=0.002) quantified at 1-month post-MI were independently associated with 1-year DD. Follow-up of the 137 patients with DD at baseline among the 159 patients showed that 36 patients (26%) had a normalized diastolic function at 1-year post-MI. Patients with a BNP>82 ng/l were less likely to improve diastolic function (OR=0.06; 95%CI=0.01-0.28; p=0.0003).Conclusions. The present study suggests that circulating levels of PIIINP, Galectin-3 and BNP may be independently associated with new-onset DD in post-MI patients

Long-term, Real-world Safety of Adalimumab in Rheumatoid Arthritis: Analysis of a Prospective US-Based Registry

OBJECTIVE: To assess long-term safety in a US cohort of rheumatoid arthritis (RA) patients treated with adalimumab in real-world clinical care settings. METHODS: This observational study analyzed the long-term incidence of safety outcomes among RA patients initiating adalimumab using data from the Corrona RA registry. Patients were adults ( \u3e /=18 years) who initiated adalimumab treatment between January 2008 and June 2017, and who had at least 1 follow-up visit. RESULTS: In total, 2798 adalimumab initiators were available for analysis, with a mean age of 54.5 years, 77% female, and mean duration of disease of 8.3 years. Nearly half (48%) were biologic naive, and 9% were using prednisone \u3e /=10 mg at adalimumab initiation. The incidence rates per 100 person-years for serious infections, congestive heart failure requiring hospitalization, malignancy (excluding nonmelanoma skin cancer), and all-cause mortality were 1.86, 0.15, 0.64, and 0.33, respectively. The incidence of serious infections was higher in the first year of therapy (3.44 [95% confidence interval: 2.45-4.84]) than subsequent years, while other measured AEs did not vary substantially by duration of exposure. The median time to adalimumab discontinuation was 11 months, while the median time to first serious infection among those experiencing a serious infection event was 12 months. CONCLUSION: Analysis of long-term data from this prospective real-world registry demonstrated a safety profile consistent with previous studies in patients with RA. This analysis did not identify any new safety signals associated with adalimumab treatment and provides valuable guidance for physicians prescribing adalimumab for extended periods of time