386 research outputs found

    Frequency-domain subspace identification of nonlinear mechanical systems - Application to a solar array structure

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    The present paper addresses the experimental identification of a simplified realisation of a solar array structure in folded configuration. To this end, a nonlinear subspace identification technique formulated in the frequency domain, referred to as the FNSI method, is exploited. The frequency response functions of the underlying linear structure and the nonlinear coefficients are estimated by this approach. Nonlinearity is caused by impacts between adjacent panels and friction and gaps appearing in their clamping interfaces. This application is challenging for several reasons, which include high modal density and the complicated nature of the involved nonlinear mechanisms

    Dynamics of viscoelastic membranes

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    We determine both the in-plane and out-of-plane dynamics of viscoelastic membranes separating two viscous fluids in order to understand microrheological studies of such membranes. We demonstrate the general viscoelastic signatures in the dynamics of shear, bending, and compression modes. We also find a screening of the otherwise two-dimensional character of the response to point forces due to the presence of solvent. Finally, we show that there is a linear, hydrodynamic coupling between the in-plane compression modes of the membrane and the out-of-plane bending modes in the case where the membrane separates two different fluids or environments

    Phase 1 Study of MK-5475, an Inhaled Soluble Guanylate Cyclase Stimulator, in Participants with Pulmonary Hypertension Associated with Chronic Obstructive Pulmonary Disease

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    Ednan K Bajwa,1 Dawn Cislak,1 Amit Kumar,1 Dan Li,1 Eric J Messina,1 Tom Reynders,2 Jean-François Denef,2 Vasile Corcea,3 Ketan P Buch,4 Eseng Lai,1 S Aubrey Stoch1 1MRL, Merck & Co., Inc., Rahway, NJ, USA; 2Translational Medicine, MSD Belgium, Brussels, Belgium; 3PMSI Republican Clinical Hospital “T. Mosneaga”, ARENSIA EM Unit, Chisinau, Republic of Moldova; 4Department of Internal Medicine, Pulmonary and Critical Care Medicine, Lexington VA Healthcare, Lexington, KY, USACorrespondence: Ednan K Bajwa, Translational Medicine, Merck Research Laboratories Massachusetts LLC, 33 Avenue Louis Pasteur, MAILSTOP BMB-3-420, Boston, MA, 02115-5727, USA, Tel +1 617 992-3470, Email [email protected]: This phase 1 study (NCT04370873) evaluated safety and pharmacokinetics/pharmacodynamics (PK/PD) of MK-5475 in participants with pulmonary hypertension associated with COPD (PH-COPD).Methods: Eligible participants were 40– 80 years old with COPD (FEV1/FVC 30% predicted) and PH (mean pulmonary arterial pressure ≥ 25 mmHg). Participants were randomized 2:1 to MK-5475 or placebo via dry-powder inhaler once daily for 7 days in Part 1 (360 μg) or 28 days in Part 2 (380 μg). Safety was assessed by adverse events (AEs) and arterial blood oxygenation. Part-2 participants had pulmonary vascular resistance (PVR; primary PD endpoint) and pulmonary blood volume (PBV; secondary PD endpoint) measured at baseline and Day 28. A non-informative prior was used to calculate posterior probability (PP) that the between-group difference (MK-5475 – placebo) in mean percent reduction from baseline in PVR was less than − 15%.Results: Nine participants were randomized in Part 1, and 14 participants in Part 2. Median age of participants (86.4% male) was 68.5 years (41– 77 years); 95.5% had moderate-to-severe COPD. Incidences of AEs were comparable between MK-5475 and placebo: overall (5/14 [36%] versus 5/8 [63%]), drug-related (1/14 [7%] versus 2/8 [25%]), and serious (1/14 [7%] versus 1/8 [13%]). MK-5475 caused no meaningful changes in arterial blood oxygenation or PBV. MK-5475 versus placebo led to numerical improvements from baseline in PVR (− 21.2% [95% CI: − 35.4, − 7.0] versus − 5.4% [95% CI: − 83.7, 72.9]), with between-group difference in PVR less than − 15% and calculated PP of 51%.Conclusion: The favorable safety profile and numerical reductions in PVR observed support further clinical development of inhaled MK-5475 for PH-COPD treatment.Keywords: pulmonary hypertension, chronic obstructive pulmonary disease, MK-5475, soluble guanylate cyclase stimulator, dry powder inhaler, pulmonary vascular resistanc

    Do nuclei go pear-shaped? Coulomb excitation of Rn-220 and Ra-224 at REX-ISOLDE (CERN)

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    Volume: 93The IS475 collaboration conducted Coulomb-excitation experiments with post-accelerated radioactive Rn-220 and Ra-224 beams at the REX-ISOLDE facility. The beam particles (E-beam: 2.83 MeV/u) were Coulomb excited using Ni-60, Cd-14, and Sn-120 scattering targets. De-excitation gamma-rays were detected employing the Miniball array and scattered particles were detected in a silicon detector. Exploiting the Coulomb-excitation code GOSIA for each nucleus several matrix elements could be obtained from the measured gamma-ray yields. The extracted matrix element allows for the conclusion that, while Rn-220 represents an octupole vibrational system, Ra-224 has already substantial octupole correlations in its ground state. This finding has i(m)plications for the search of CP-violating Schiff moments in the atomic systems of the adjacent odd-mass nuclei.Peer reviewe

    Pandemic A/H1N1v influenza 2009 in hospitalized children: a multicenter Belgian survey

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    <p>Abstract</p> <p>Background</p> <p>During the 2009 influenza A/H1N1v pandemic, children were identified as a specific "at risk" group. We conducted a multicentric study to describe pattern of influenza A/H1N1v infection among hospitalized children in Brussels, Belgium.</p> <p>Methods</p> <p>From July 1, 2009, to January 31, 2010, we collected epidemiological and clinical data of all proven (positive H1N1v PCR) and probable (positive influenza A antigen or culture) pediatric cases of influenza A/H1N1v infections, hospitalized in four tertiary centers.</p> <p>Results</p> <p>During the epidemic period, an excess of 18% of pediatric outpatients and emergency department visits was registered. 215 children were hospitalized with proven/probable influenza A/H1N1v infection. Median age was 31 months. 47% had ≥ 1 comorbid conditions. Febrile respiratory illness was the most common presentation. 36% presented with initial gastrointestinal symptoms and 10% with neurological manifestations. 34% had pneumonia. Only 24% of the patients received oseltamivir but 57% received antibiotics. 10% of children were admitted to PICU, seven of whom with ARDS. Case fatality-rate was 5/215 (2%), concerning only children suffering from chronic neurological disorders. Children over 2 years of age showed a higher propensity to be admitted to PICU (16% vs 1%, p = 0.002) and a higher mortality rate (4% vs 0%, p = 0.06). Infants less than 3 months old showed a milder course of infection, with few respiratory and neurological complications.</p> <p>Conclusion</p> <p>Although influenza A/H1N1v infections were generally self-limited, pediatric burden of disease was significant. Compared to other countries experiencing different health care systems, our Belgian cohort was younger and received less frequently antiviral therapy; disease course and mortality were however similar.</p
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