9,034 research outputs found

    Design of a THz-MEMS frequency selective surface for structural health monitoring

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    This paper characterizes the relationship between applied force and reflectance/ transmittance of a terahertz frequency selective surface for use as a sensor in structural health monitoring. Numerical modelling of both the mechanical and electromagnetics, solving the elasticity equation and Maxwell’s equations, respectively, has been undertaken for a 3 layer device. The unit cell comprises of a metal cross wire embedded within a (hard) silicon substrate, interleaved with stacks of (soft) low density polyethylene

    Prognosis following acute coronary syndromes according to prior coronary artery bypass grafting: Meta-analysis

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    PURPOSE: Conduct a meta-analysis to study the prognostic influence of a previous coronary artery bypass grafting (CABG) in patients admitted for an acute coronary syndrome (ACS). METHODS: A systematic review of the literature was performed using electronic reference databases through January 2013 (MEDLINE, Cochrane Library, Web of Knowledge, Google Scholar and references cited in other studies). Studies in which ACS outcomes with a previous history of CABG were compared with ACS outcomes with no history of previous CABG were considered for inclusion. The main endpoints of interest were mortality and non-fatal acute myocardial infarction. Data was aggregated at three follow-up times using random-effects meta-analysis models. RESULTS: Twenty-four studies were included which provided 387,181 patients for analysis. Previous CABG ACS patients were older, more diabetic and had a more frequent history of a previous myocardial infarction. Pooled in-hospital mortality was higher for the previous CABG ACS patients (OR 1.22 [1.04-1.44], p<0.01, I(2) 88%). The pooled adjusted OR showed no significant differences for the two groups (adjusted OR 1.13 [0.93-1.37], p=0.22, I(2) 92%). Previous CABG ACS patient had a higher pooled 30-day mortality (OR 1.28 [1.05-1.55], p=0.02, I(2) 74%); a higher non-adjusted (OR 1.61 [1.38-1.88], p<0.01, I(2) 70%) and adjusted (adjusted OR 1.37 [1.15-1.65], p<0.01, I(2) 0%) long-term mortality. Both the in-hospital and the long-term re-infarction rates were higher for the previous CABG ACS patients. CONCLUSIONS: According to our data, ACS patients with previous CABG history had a higher risk for short- and long-term adverse events

    Socially responsible consumers and stockpiling during crises: the intersection of personal norms and fear

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    Purpose - Urging people to avoid stockpiling was a common declaration made by governments during the COVID-19 pandemic outbreak, yet empty supermarket shelves and supply shortages of basic products were observed worldwide. This study aims to (a) identify the factors that activate consumer personal norms towards socially responsible behaviours, specifically resisting stockpiling, and (b) examine how fear moderates the link between personal norms and consumer engagement in stockpiling during public crises. Design/methodology/approach - The study recruited a sample of US consumers who were responsible for household grocery shopping during the COVID-19 pandemic. A total of 593 individuals participated in the study, and the collected data were analysed using structural equation modelling. Findings - The results show that awareness of the negative consequences of stockpiling and a sense of personal responsibility for those consequences activate personal norms towards responsible shopping during public crises. However, perceived fear has the opposite effect, encouraging stockpiling. In addition, fear weakens the negative relationship between personal norms and stockpiling. Originality/value - This study extends the norm activation model and indicates that personal norms may not always promote responsible behaviours when fear is high. It is unique in that it sheds light on non-mainstream responsible consumption behaviours (e.g. resisting stockpiling), and the interaction between consumption and social responsibility

    Surface roughness dependent osteoblast and fibroblast response on poly(l-lactide) films and electrospun membranes

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    Poly(l-lactide) electrospun mats with random and aligned fiber orientation and films have been produced with degrees of crystallinity ranging from 0 up to nearly 50%. The overall surface roughness is practically constant irrespective of the sampling areas (1 × 1 µm to 20 × 20 µm) for degrees of crystallinity below 30%, increasing for higher degrees of crystallinity for the larger sampling areas. Further, due to fiber confinement, surface roughness variations are smaller in electrospun mats. Samples with 50% of crystallinity show the lowest osteoblast and the highest fibroblast proliferation. Therefore, it is verified that higher roughness promotes lower osteoblast but higher fibroblast proliferation. The overall results indicate the relevant role of the sub-microenvironment variations associated to the microscale roughness in determining the different cell responses.Portuguese Foundation for Science and Technology (FCT); contract grant numbers: C/FIS/UI607/2011, PTDC/CTM-NAN/112574/2009, contract grant numbers: SFRH/BPD/63148/2009, SFRH/BPD/90870/2012, Matepro—Optimizing Materials and Processes, Programa Operacional Regional do Norte, Quadro de Referência Estratégico Nacional” (QREN), “Fundo Europeu de Desenvolvimento Regional” (FEDER); contract grant number: NORTE-07–0124-FEDER-000037

    Circulating micrornas correlate with multiple myeloma and skeletal osteolytic lesions

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    Multiple myeloma (MM) is the second most frequent hematological disease and can cause skeletal osteolytic lesions. This study aims to evaluate the expression of circulating microRNAs (miR-NAs) in MM patients and to correlate those levels with clinicopathological features, including bone lesions. A panel of miRNAs associated with MM onset and progression, or with bone remodeling, was analyzed in the plasma of 82 subjects (47 MM patients; 35 healthy controls). Results show that miR-16-5p, miR-20a-5p, and miR-21-5p are differently expressed between MM patients and healthy controls. Receiver operating characteristic analyses indicate that their combined expression has potential as a molecular marker (Area Under the Curve, AUC of 0.8249). Furthermore, significant correlations were found between the analyzed miRNAs and disease stage, treatment, ß2 microglobulin, serum albumin and creatinine levels, but not with calcium levels or genetic alterations. In this cohort, 65.96% of MM patients had bone lesions, the majority of which were in the vertebrae. Additionally, miR-29c-3p was decreased in patients with osteolytic lesions compared with patients without bone disease. Interestingly, circulating levels of miR-29b-3p correlated with cervical and thoracic vertebral lesions, while miR-195-5p correlated with thoracic lesions. Our findings suggest circulating miRNAs can be promising biomarkers for MM diagnosis and that their levels correlate with myeloma bone disease and osteolytic lesions.The project was supported by AO Spine-ESA Grant Award 2018 (AO Foundation); As-sociação Portuguesa Contra a Leucemia, Sociedade Portuguesa de Hematologia, AMGEN; and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project POCI-01-0145-FEDER-031402-R2Bone (FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation—POCI, Portugal 2020)

    A Rare Variation of the Extensor Indicis Proprius Tendon With Important Clinical Implications

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    Introduction: Anatomical variations of the extensor tendons to the fingers are of great clinical interest, due to the relatively high frequency of tendon injury in clinical practice. Material and methods: During routine dissection of the right upper limb of a 67-year-old female preserved corpse, the extensor indicis proprius (EIP) muscle belly originated 3 independent tendons, each with a separate fascial sheath, forming a triple EIP tendon. There was a larger tendon, which occupied a central position, that represented the usual single EIP tendon. In addition, there were two thinner radial and ulnar accessory EIP tendons. The radial-EIP tendon crossed deep to the extensor digitorum communis (EDC) tendon to the index finger in the distal half of the dorsum of the hand to reach the radial side of the extensor expansion hood of the index finger. Discussion: According to the literature, the frequency of a triple EIP tendon ranges from 0%, to as high as 7%, although most authors do not acknowledge the presence of this variant in their series. This variant of the EIP tendon, in which the radial-EIP terminated laterally to the termination of the tendon of the EDC to the index finger, may be a source of confusion intraoperatively, as the EIP tendon has traditionally been identified on the basis of its ulnar location with respect to the EDC tendon. Conclusion: The possibility of a triple EIP tendon should certainly be born in mind by all surgeons when performing tendon repairs, tenoplasties or tendon transfers

    Towards Studying Hierarchical Assembly in Real Time: A Milky Way Progenitor Galaxy at z = 2.36 under the Microscope

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    We use Hubble Space Telescope (HST) imaging and near-infrared spectroscopy from Keck/MOSFIRE to study the sub-structure around the progenitor of a Milky Way-mass galaxy in the Hubble Frontier Fields (HFF). Specifically, we study an re=4030+70r_e = 40^{+70}_{-30}pc, M108.2MM_{\star} \sim 10^{8.2} M_{\odot} rest-frame ultra-violet luminous "clump" at a projected distance of \sim100~pc from a M109.8M_{\star} \sim 10^{9.8}M_{\odot} galaxy at z=2.36z = 2.36 with a magnification μ=5.21\mu = 5.21. We measure the star formation history of the clump and galaxy by jointly modeling the broadband spectral energy distribution from HST photometry and Hα\alpha from MOSFIRE spectroscopy. Given our inferred properties (e.g., mass, metallicity, dust) of the clump and galaxy, we explore scenarios in which the clump formed \emph{in-situ} (e.g., a star forming complex) or \emph{ex-situ} (e.g., a dwarf galaxy being accreted). If it formed \emph{in-situ}, we conclude that the clump is likely a single entity as opposed to a aggregation of smaller star clusters, making it one of the most dense star clusters cataloged. If it formed \emph{ex-situ}, then we are witnessing an accretion event with a 1:40 stellar mass ratio. However, our data alone are not informative enough to distinguish between \emph{in-situ} and \emph{ex-situ} scenarios to a high level of significance. We posit that the addition of high-fidelity metallicity information, such as [OIII]4363\AA, which can be detected at modest S/N with only a few hours of JWST/NIRSpec time, may be a powerful discriminant. We suggest that studying larger samples of moderately lensed sub-structures across cosmic time can provide unique insight into the hierarchical formation of galaxies like the Milky Way.Comment: Accepted to MNRA

    Proton pump inhibitors in patients treated with aspirin and clopidogrel after acute coronary syndrome

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    INTRODUCTION: Clopidogrel is an antiplatelet agent converted to its active metabolite by cytochrome P-450 isoenzymes. Numerous drugs are known to inhibit P-450 isoenzymes, including proton pump inhibitors (PPIs), which are often associated with aspirin and clopidogrel to prevent adverse gastrointestinal effects. In vitro studies first showed that PPIs reduced the antiplatelet effect of clopidogrel, while recent clinical studies have raised concerns that the addition of a PPI to clopidogrel in acute coronary syndrome (ACS) patients could actually increase the risk of recurrent cardiovascular events. OBJECTIVE: The aim of this study was to evaluate whether the prescription of a PPI conferred a worse prognosis in patients discharged with aspirin and clopidogrel treatment after ACS. METHODS: A total of 876 patients admitted with ACS and discharged with aspirin and clopidogrel, with a planned duration of at least six months, from January 2004 to March 2008, were reviewed. Patients were classified in two groups according to whether or not a PPI was prescribed at discharge. The PPIs considered were those mainly metabolized by cytochrome P-450 2C19. We excluded patients with insufficient information available on either prescription or clinical records that could allow clearly confirm or exclude exposure to a PPI. Primary end points were six-month all-cause mortality and the composite of death, myocardial infarction and unstable angina at six months. RESULTS: Of the 802 patients considered for further analysis, 274 (34.2%) individuals were medicated with a PPI in addition to dual antiplatelet therapy. Patients taking PPIs were older, more often had renal insufficiency and less often had a history of coronary revascularization and smoking. They more often presented with Killip class >I and lower hemoglobin concentration on admission. There were no significant differences between the two groups in terms of medical treatment (during hospital stay and at discharge) or invasive procedures. By multivariate analysis, independent and positive predictors of PPI prescription were older age and lower hemoglobin concentration on admission. Patients taking PPIs had a slightly higher prevalence of six-month mortality (6.5% vs. 3.9%) and of the composite end point (12.9% vs. 9.2%), although without statistical significance. By multivariate analysis including potential confounding variables, the prescription of a PPI on top of aspirin and clopidogrel was still n ot associated with a worse prognosis. CONCLUSIONS: In the present study, PPI precription in addition to aspirin and clopidogrel after ACS was not associated with a worse six-month prognosis
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