1,605 research outputs found
Localized waves in elastic plates with perturbed honeycomb arrays of constraints
No full textIn this paper, we study wave propagation in elastic plates incorporating honeycomb arrays of rigid pins. In particular, we demonstrate that topologically non-trivial band-gaps are obtained by perturbing the honeycomb arrays of pins such that the ratio between the lattice spacing and the distance of pins is less than 3; conversely, a larger ratio would lead to the appearance of trivial stop-bands. For this purpose, we investigate band inversion of modes and calculate the valley Chern numbers associated with the dispersion surfaces near the band opening, since the present problem has analogies with the quantum valley Hall effect. In addition, we determine localized eigenmodes in strips, repeating periodically in one direction, that are subdivided into a topological and a trivial section. Finally, the outcomes of the dispersion analysis are corroborated by numerical simulations, where a time-harmonic point source is applied to a plate with finite arrays of rigid pins to create localized waves immune to backscattering. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 1)'
Experimental investigation of the temperature effect on the structural response of SG-laminated reinforced glass beams
No full textTo generate high-level redundancy for structural glass beams, a novel concept of laminating a metal reinforcement to a structural glass beam has been developed at Delft University of Technology (TU Delft). This concept makes use of the relatively stiff polymer interlayer material SentryGlas (SG) to bond the metal to the glass. However, due to the visco-elastic properties of the SG, its stiffness varies at different temperature levels. To what extent this temperature dependency has an effect on the structural response of the beam composite has been experimentally investigated in cooperation with Ghent University (UGent) and is the subject of current publication. Two separate series of pull-out tests, to investigate the bond strength, and beam tests, to investigate the post-breakage response, have been conducted at -20, 23 and 60 degrees C. The pull-out tests revealed a high temperature dependency of the bond strength of SG. This temperature dependency also had an effect on the structural response of the beams. However, regardless of temperature level all beams showed high-level plastic response and high redundancy. It is therefore concluded that temperature levels of -20 to 60 degrees C do not endanger the structural safety of SG-laminated reinforced glass beams.RESSLA
Blocking TLR-TICAM-1 pathway by RSV sG
No full textMonocyte-derived dendritic cells (mDCs) recognize viral RNA extrinsically by TLR3 on the membrane and intrinsically RIG-I/MDA5 in the cytoplasm to induce type I interferons (IFNs) and mDC maturation. When mDCs were treated with live or UV-irradiated respiratory syncytial virus (RSV), early (~4 h) induction of IFN-β detected in other virus infections was barely observed. Live RSV subsequently replicated to activate the cytoplasmic IFN-inducing pathway leading to robust type I IFN induction. We found that RSV initial attachment to cells blocked polyI:C-mediated IFN-β induction, and this early IFN-β-modulating event was abrogated by Abs against envelope proteins of RSV, demonstrating the presence of a IFN-regulatory mode by early RSV attachment to host cells. By IFN-stimulated response element (ISRE) reporter analysis in HEK293 cells, polyI:C- or LPS-mediated ISRE activation was dose-dependently inhibited by live and inactive RSV to a similar extent. Of the RSV envelope proteins, simultaneously-expressed or exogenously-added RSV G or soluble G (sG) proteins inhibited TLR3/4-mediated ISRE activation in HEK293 cells. sG proteins expressed in cells did not affect the RIG-I/MDA5 pathway but inhibited the TLR adaptor TRIF/TICAM-1 pathway for ISRE activation. Finally, extrinsically-added sG protein suppressed the production of IFN-β in mDCs. Although the molecular mechanism of this extrinsic functional mode of the RSV G protein remains undetermined, G proteins may neutralize the F protein function that promotes IFN-mediated mDC modulation via TLR4 and may cause insufficient raising cell-mediated immunity against RSV
Preliminary survey of araceae of Sg. Rawog conservation Area, Segaliud Lokan forest researve (FMU 19B)
No full textConsidering that Sg. Rawog Conservation Area has been logged, it was thus with considerable surprise that the author encountered Rhaphidophora fluminea Ridl. along the river bank of Sg. Rawog since its first collection in 1897 from Bonggaya. Homalomena gempal Kartini, P.C Boyce and W.S Yeng was found growing on the sandstone of the river bank. Two interesting species of Schismatoglottis belong to the Trifiscata Complex were found not far from river bank of Trail 11. Alocasia princeps W. Bull and A. sarawakensis M. Hotta were found inside the forest at all trails except in the heath forest (Trail C49). Aroids climbers, namely Amydrium medium (Zoll. & Moritzi) Nicolson, Pothos sp., Rhaphidophora lativeginata M. Hotta, Scindapsus pictus Hassk. and Scindapsus sp. were found scattered in the inner area of the forest. In conclusion, the area around the river bank of Sg. Rawog represented aroid species found in pristine forest
Temporal and spatial variability in speakers with Parkinson's Disease and Friedreich's Ataxia
No full textSpeech variability in groups of speakers with Parkinson's disease (PD) and with Friedreich's ataxia was compared with healthy controls. Speakers repeated the same phrase 20 times at one of two rates (fast or habitual). A non-linear analysis of variability was performed which used some of the principles behind the spatio-temporal index (STI). The STI usually employs variation in lip displacement over repetitions of the same utterance and a linear analysis of such signals is conducted to represent the combined variation in spatial and temporal control. When working with patients, audio measures (here we used speech energy) are preferred over kinematics ones as they are minimally disruptive to speech. Non-linear methods allow spatial variability to be estimated separately from temporal variability. The results are tentatively interpreted as showing that PD speakers were distinguished from healthy control speakers in spatial variability and ataxic speakers were distinguished from controls in temporal variability. These findings are consistent with the speech symptoms reported for these disorders. We conclude that the non-linear analysis using the speech energy measure is worth investigating further as it is potentially revealing of the differences underlying these two pathologies
Salivary gland ultrasound abnormalities in primary Sj\uf6gren\u27s syndrome: Consensual US-SG core items definition and reliability
No full text\ua9 Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted. Objectives Ultrasonography (US) is sensitive for detecting echostructural abnormalities of the major salivary glands (SGs) in primary Sj\uf6gren\u27s syndrome (pSS). Our objectives were to define selected US-SG echostructural abnormalities in pSS, set up a preliminary atlas of these definitions and evaluate the consensual definitions reliability in both static and acquisition US-SG images. Methods International experts in SG US in pSS participated in consensus meetings to select and define echostructural abnormalities in pSS. The US reliability of detecting these abnormalities was assessed using a two-step method. First 12 experts used a web-based standardised form to evaluate 60 static US-SG images. Intra observer and interobserver reliabilities were expressed in κ values. Second, five experts, who participated all throughout the study, evaluated US-SG acquisition interobserver reliability in pSS patients. Results Parotid glands (PGs) and submandibular glands (SMGs) intra observer US reliability on static images was substantial (κ > 0.60) for the two main reliable items (echogenicity and homogeneity) and for the advised pSS diagnosis. PG inter observer reliability was substantial for homogeneity. SMGs interobserver reliability was moderate for homogeneity (κ = 0.46) and fair for echogenicity (κ = 0.38). On acquisition images, PGs interobserver reliability was substantial (κ > 0.62) for echogenicity and moderate (κ = 0.52) for homogeneity. The advised pSS diagnosis reliability was substantial (κ = 0.66). SMGs interobserver reliability was fair (0.20< κ ≤ 0.40) for echogenicity and homogeneity and either slight or poor for all other US core items. Conclusion This work identified two most reliable US-SG items (echogenicity and homogeneity) to be used by US-SG trained experts. US-PG interobserver reliability result for echogenicity is in line with diagnosis of pSS
A multi-stage genome-wide association study of bladder cancer identifies multiple susceptibility loci.
No full textWe conducted a multi-stage, genome-wide association study of bladder cancer with a primary scan of 591,637 SNPs in 3,532 affected individuals (cases) and 5,120 controls of European descent from five studies followed by a replication strategy, which included 8,382 cases and 48,275 controls from 16 studies. In a combined analysis, we identified three new regions associated with bladder cancer on chromosomes 22q13.1, 19q12 and 2q37.1: rs1014971, (P = 8 × 10⁻¹²) maps to a non-genic region of chromosome 22q13.1, rs8102137 (P = 2 × 10⁻¹¹) on 19q12 maps to CCNE1 and rs11892031 (P = 1 × 10⁻⁷) maps to the UGT1A cluster on 2q37.1. We confirmed four previously identified genome-wide associations on chromosomes 3q28, 4p16.3, 8q24.21 and 8q24.3, validated previous candidate associations for the GSTM1 deletion (P = 4 × 10⁻¹¹) and a tag SNP for NAT2 acetylation status (P = 4 × 10⁻¹¹), and found interactions with smoking in both regions. Our findings on common variants associated with bladder cancer risk should provide new insights into the mechanisms of carcinogenesis
Laminated connections under tensile load at different temperatures and strain rates
No full textIn the last years, a novel typology of adhesive connections for structural glass application has emerged, known as laminated adhesive connections, which makes use of the transparent ionomer SentryGlas® (SG) from Kuraray and the Transparent Structural Silicon Adhesive (TSSA) from Dow Corning. Despite being used in several projects, limited information is available in literature on their mechanical behaviour and on the effects of strain rate and temperature. In this work the behaviour of laminated connections under tensile loading is studied by means of experimental, analytical and numerical analyses. The experimental investigations show that temperature and strain rate variations have important effects on the mechanical response of the connections. Two main interesting phenomena are also observed: the whitening phenomenon in TSSA and the development of bubble within the SG adhesive. The analytical studies of the stress state show that confinement state of the adhesive induces a non-uniform three-dimensional stress distribution in the adhesive with a dominant hydrostatic component of the stress tensor, which is observed to be in agreement with the experimental results. Three-dimensional finite numerical analyses show that the stress field deviates from the uniform distribution with a large gradient of hydrostatic and deviatoric stresses over the adhesive area. The output of the finite numerical model are then compared with the observations of the experimental campaigns. Herein, the full set of numerical results is synthetized by the definition of so-called stress factors. The latter allow to derive the three-dimensional stress state in the adhesive at different temperatures and to compute the stress peak in the non-linear stress field distribution. Finally, prediction models are proposed for the tensile resistance of TSSA and SG laminated connections. A logarithmic law is proposed for the strain rate effects for both TSSA and SG connections. Linear and inverse hyperbolic-tangent-based laws are instead proposed for the TSSA and SG temperature effects, respectively.Accepted Author ManuscriptOLD Structural Desig
Causal links in QOL sub-domains accentuate greater support for physical and emotional well-being of breast cancer survivors
No full textGroup psychotherapy or support group (SG) interventions have been reported to improve the quality of
life (QOL) of cancer patients. For an improved life of Malaysian breast cancer survivors, facilities for SG
interventions have been set up both in the urban and rural areas of the country. However, the impact of
support group participation on QOL of these patients, and factors that may influence it have remained
elusive. This study, examines the impact of SG participation on the QOL of Malaysian breast cancer
survivors using the Functional Assessment of Chronic Illness Therapy (FACIT) questionnaire. Multiple
comparisons using the Tukey HSD show that the QOL measure for rural SG participants are significantly
lower (F(2,55) = 14.570; p < 0.01) than for urban SG participants. Analysis of the interrelationships
between the QOL sub-domains indicated that functional wellbeing (FWB) fully mediates the effects of
physical wellbeing (PWB) and emotional wellbeing (EWB) on social wellbeing (SWB). In addition, PWB
was relatively more influential than EWB in determining patients’ FWB and SWB while PWB, EWB and
FWB collectively explained about 25% of the variability in SWB. Findings of this study thus indicate that
measurement of QOL is relative to patients’ location i.e., urban or rural, which in turn reflects the
patients’ education and financial background
Active exterior cloaking of an inclusion with evanescent multipole devices for flexural waves in thin plates
No full textWe present an active exterior cloak for flexural waves propagating in a Kirchhoff plate of infinite extent. The evanescent multipole devices are characterized by Macdonald functions Kn of the required order, which, assuming time-harmonic vibrations, are solutions of the fourth-order biharmonic equation. It is shown that in the region of interfering waves, which emanate from the devices, a field is recreated which cancels the incident wave to yield a region of 'stillness'. An inclusion is then positioned in this region for further investigation, with additional attention given to the boundary condition. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 2)'
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