Uniform Foam Crush Testing for Multi-Mission Earth Entry Vehicle Impact Attenuation

Multi-Mission Earth Entry Vehicles (MMEEVs) are blunt-body vehicles designed with the purpose of transporting payloads from outer space to the surface of the Earth. To achieve high-reliability and minimum weight, MMEEVs avoid use of limited-reliability systems, such as parachutes and retro-rockets, instead using built-in impact attenuators to absorb energy remaining at impact to meet landing loads requirements. The Multi-Mission Systems Analysis for Planetary Entry (M-SAPE) parametric design tool is used to facilitate the design of MMEEVs and develop the trade space. Testing was conducted to characterize the material properties of several candidate impact foam attenuators to enhance M-SAPE analysis. In the current effort, four different Rohacell foams are tested at three different, uniform, strain rates (approximately 0.17, approximately 100, approximately 13,600%/s). The primary data analysis method uses a global data smoothing technique in the frequency domain to remove noise and system natural frequencies. The results from the data indicate that the filter and smoothing technique are successful in identifying the foam crush event and removing aberrations. The effect of strain rate increases with increasing foam density. The 71-WF-HT foam may support Mars Sample Return requirements. Several recommendations to improve the drop tower test technique are identified

N-terminal pro-brain natriuretic peptide in a novel screening algorithm for pulmonary arterial hypertension in systemic sclerosis: a case-control study

INTRODUCTION: Pulmonary arterial hypertension is a major cause of mortality in systemic sclerosis. N-terminal probrain natriuretic peptide (NT-proBNP) has emerged as a candidate biomarker that may enable the early detection of systemic sclerosis-related pulmonary arterial hypertension (SSc-PAH). The objective of our study was to incorporate NT-proBNP into a screening algorithm for SSc-PAH that could potentially replace transthoracic echocardiography (TTE) as a more convenient and less costly “first tier” test. METHODS: NT-proBNP levels were measured in patients from four clinical groups: a group with right heart catheter (RHC)-diagnosed SSc-PAH before commencement of therapy for PAH; a group at high risk of SSc-PAH based on TTE; a group with interstitial lung disease; and systemic sclerosis (SSc) controls with no cardiopulmonary complications. NT-proBNP levels were compared by using ANOVA and correlated with other clinical variables by using simple and multiple linear regression. ROC curve analyses were performed to determine the optimal cut point for NT-proBNP and other clinical variables in prediction of PAH. RESULTS: NT-proBNP was highest in the PAH group compared with other groups (P < 0.0001), and higher in the risk group compared with controls (P < 0.0001). NT-proBNP was positively correlated with systolic pulmonary artery pressure (PAP) on TTE (P < 0.0001), and mean PAP (P = 0.013), pulmonary vascular resistance (P = 0.005), and mean right atrial pressure (P = 0.006) on RHC. A composite model wherein patients screened positive if NT-proBNP was ≥ 209.8 pg/ml, and/or DLCOcorr was < 70.3% with FVC/DLCOcorr ≥ 1.82, had a sensitivity of 100% and specificity of 77.8% for SSc-PAH. CONCLUSION: We have proposed a screening algorithm for SSc-PAH, incorporating NT-proBNP level and PFTs. This model has high sensitivity and specificity for SSc-PAH and, if positive, should lead to TTE and confirmatory testing for PAH. This screening algorithm must be validated prospectively.Vivek Thakkar, Wendy M. Stevens, David Prior, Owen A. Moore, Jillian Byron, Danny Liew, Karen Patterson, Pravin Hissaria, Janet Roddy, Jane Zochling, Joanne Sahhar, Peter Nash, Kathleen Tymms, David Celermajer, Eli Gabbay, Peter Youssef, Susanna M. Proudman and Mandana Nikpou

S.4.1 N-terminal pro-brain natriuretic peptide levels predict incident pulmonary arterial hypertension in SSc

Introduction. Pulmonary arterial hypertension (PAH) is a major cause of mortality in SSc. NT-proBNP may be a useful biomarker of prevalent PAH but its role in screening for incident PAH has not been evaluated. Methods. Patients recruited into the Australian Scleroderma Cohort Study undergo annual echocardiography, pulmonary function tests (PFTs), 6-min walk test (6MWT) and have serum NT-proBNP measured (ElecsysproBNP II). The diagnosis of PAH is based on Dana point criteria at right heart catheterization (RHC). Patients with LV dysfunction or eGFR 36 mmHg, (ii) FVC/DLCO% >1.6 and no significant ILD, (iii) DLCO 189.2 pg/ml had a likelihood ratio of 26.4 for presence of PAH (c-statistic = 0.9; sensitivity 85%; specificity 97%). An NT-proBNP level 189.2 pg/ml and <82.9 pg/ml defining patients with a high and low likelihood of PAH, respectively. Further prospective studies are required in unselected patients in order to confirm these finding

AD51B in Familial Breast Cancer

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C&gt;T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

Novel biomarkers of dysregulated angiogenesis are not specific to pulmonary arterial hypertension in systemic sclerosis

Scientific Poster ARA-P48V. Thakkar, K. Patterson, W. Stevens., J. Byron, O. Moore, J. Roddy, J. Zochling, J. Sahhar, P. Nash, K. Tymms, P. Youssef, S. Proudman, M. Nikpour, P. Hissari

Serum ICAM-1 levels are related to the presence of interstitial lung disease in SSc

Poster abstract PS05V. Thakkar, K. Patterson, W. Stevens, J. Byron, O. Moore, J. Roddy, J. Zochling, J. Sahhar, P. Nash, K. Tymms, P. Youssef, S. Proudman, P. Hissaria, and M. Nikpou

N-terminal pro-brain natriuretic peptide levels predict incident pulmonary arterial hypertension in SSc

Abstract S.4.1V. Thakkar, W. Stevens, D. Prior, J. Byron, K. Patterson, P. Hissaria, O. Moore, J. Roddy, J. Zochling, J. Sahhar, P. Nash, K. Tymms, P. Youssef, S. Proudman, and M. Nikpo

N-terminal pro-brain natriuretic peptide in a novel screening algorithm for pulmonary arterial hypertension in systemic sclerosis

Abstract AR18V. Thakkar, W. Stevens, D. Prior, O. Moore, J. Byron, K. Patterson, P. Hissaria, J. Roddy, J. Zochling, J. Sahhar, P. Nash, K. Tymms, D. Celermajer, E. Gabbay, P. Youssef, S. Proudman, M. Nikpou