36 research outputs found

    Evaluation of Load Transfer in the Cellulosic-Fiber/Polymer Interphase Using a Micro-Raman Tensile Test

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    The objectives of this research were (1) to use a Raman micro-spectroscopic technique to determine the tensile stress distributions of a cellulosic-fiber/polymer droplet interphase, and (2) to examine if the stress profile could be used to evaluate load transfer in fiber/polymer adhesion. Cellulosic fibers were treated with various silanes (amino, phenylamino, phenyl, and octadecyl functionalities) and a styrene-maleic anhydride copolymer to create different interphases upon bonding with polystyrene. A single fiber, bonded with a micro-droplet of polystyrene in the mid-span region of its gage length, was strained in tension. Raman spectra were collected at five-micrometer intervals along the embedded region of the fiber. The stress-dependent peak of cellulose (895 cm-1) was analyzed for frequency shift so that the local tensile stress in the interface region could be determined. Results showed that the local tensile stresses of the strained fiber were lower in the embedded region compared to the exposed region, suggesting a transfer of load from the fiber to the matrix polymer. A deeper and sharper decline of the stress profile was observed when the fiber/droplet interaction was enhanced. Further analyses, involving conversion of tensile stress profiles to shear stress distributions in the interphase, confirmed that the micro-Raman/tensile test can be employed to evaluate fiber/matrix interfacial bonding in composites. This success signifies the possibility of evaluating adhesion between cellulosic fibers and brittle polymers, which is difficult to study using common micromechanical tests. Use of the micro-Raman technique can improve our understanding of wood/polymer adhesion

    Secretory leucoprotease inhibitor binds to NF-κB binding sites in monocytes and inhibits p65 binding

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    Secretory leucoprotease inhibitor (SLPI) is a nonglycosylated protein produced by epithelial cells. In addition to its antiprotease activity, SLPI has been shown to exhibit antiinflammatory properties, including down-regulation of tumor necrosis factor α expression by lipopolysaccharide (LPS) in macrophages and inhibition of nuclear factor (NF)-κB activation in a rat model of acute lung injury. We have previously shown that SLPI can inhibit LPS-induced NF-κB activation in monocytic cells by inhibiting degradation of IκBα without affecting the LPS-induced phosphorylation and ubiquitination of IκBα. Here, we present evidence to show that upon incubation with peripheral blood monocytes (PBMs) and the U937 monocytic cell line, SLPI enters the cells, becoming rapidly localized to the cytoplasm and nucleus, and affects NF-κB activation by binding directly to NF-κB binding sites in a site-specific manner. SLPI can also prevent p65 interaction with the NF-κB consensus region at concentrations commensurate with the physiological nuclear levels of SLPI and p65. We also demonstrate the presence of SLPI in nuclear fractions of PBMs and alveolar macrophages from individuals with cystic fibrosis and community-acquired pneumonia. Therefore, SLPI inhibition of NF-κB activation is mediated, in part, by competitive binding to the NF-κB consensus-binding site

    Advances in Molecular Quantum Chemistry Contained in the Q-Chem 4 Program Package

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    A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Møller–Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Recognition and Redistribution in Theories of Justice Beyond the State

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    We consider here how cultural and socioeconomic dimensions of justice beyond the state are related. First we examine cosmopolitan theories that have drawn on John Rawls's egalitarian liberal framework to argue that a just global order requires substantive, transnational redistribution of material resources. We then assess the view, ironically put forward by Rawls himself, that this perspective is ethnocentric and insufficiently tolerant of non-liberal cultures. We argue that Rawls is right to be concerned about the danger of ethnocentrism, but wrong to assume that this requires us to reject the case for substantive redistribution across state boundaries. A more compelling account of justice beyond the state will integrate effectively socioeconomic and cultural aspects of justice. We suggest that this approach is best grounded in a critical theory of recognition that responds to the damage caused to human relations by legacies of historical injustice.</p

    Outcome of total hip and knee arthroplasty in HIV-infected patients: A systematic review

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    Significant advances in the treatment of Human Immunodeficiency Virus (HIV) have occurred in recent times, with life expectancy now approaching the normal population. Therefore, patients with HIV will increasingly be undergoing joint replacement in the future, however concerns remain regarding the complications and outcome in this patient cohort. The aim was to assess the outcome of total hip and knee arthroplasty in HIV-infected patients. A systematic search of the literature using MOOSE reporting guidelines was performed to assess the outcome of hip and knee arthroplasty in HIV-infected patients. The primary outcome was infection. Secondary outcome was all-cause revision. The search yielded 552 results, of which 19 met the inclusion criteria, comprising 5.819.412 joint replacements. The overall quality of the studies was poor with significant heterogeneity between the studies. Infection and revision appeared to be more likely to occur in HIV positive patients compared to HIV negative patients. A subgroup analysis of four studies revealed a risk ratio of 3.31 and 2.25 for increase in infection and revision respectively in HIV positive patients. This systematic review and meta-analysis demonstrates an increased risk of infection and revision in HIV infected patients undergoing total hip and knee arthroplasty. However, these findings are based on poor quality evidence in a limited number of studies and need to be interpreted with caution. Further research should concentrate on large, well-designed, prospective studies, that control for co-morbidities and employ standardised outcome measures to allow for direct comparison

    Secretory Leucoprotease Inhibitor Impairs Toll-Like Receptor 2- and 4-Mediated Responses in Monocytic Cells

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    Secretory leucoprotease inhibitor (SLPI) is an anti-inflammatory antiprotease which can inhibit lipopolysaccharide-induced NF-κB activation. We examined its ability to inhibit NF-κB activation induced by lipoteichoic acid and investigated the effects of oxidation or complex formation with neutrophil elastase on SLPI's anti-inflammatory properties in U937 myelomonocytic cells and macrophages
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