606 research outputs found

    Plasma from Volunteers Breathing Helium Reduces Hypoxia-Induced Cell Damage in Human Endothelial Cells-Mechanisms of Remote Protection Against Hypoxia by Helium.

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    PurposeRemote ischemic preconditioning protects peripheral organs against prolonged ischemia/reperfusion injury via circulating protective factors. Preconditioning with helium protected healthy volunteers against postischemic endothelial dysfunction. We investigated whether plasma from helium-treated volunteers can protect human umbilical vein endothelial cells (HUVECs) against hypoxia in vitro through release of circulating of factors.MethodsHealthy male volunteers inhaled heliox (79% helium, 21% oxygen) or air for 30 min. Plasma was collected at baseline, directly after inhalation, 6 h and 24 h after start of the experiment. HUVECs were incubated with either 5% or 10% of the plasma for 1 or 2 h and subjected to enzymatically induced hypoxia. Cell damage was measured by LDH content. Furthermore, caveolin 1 (Cav-1), hypoxia-inducible factor (HIF1α), extracellular signal-regulated kinase (ERK)1/2, signal transducer and activator of transcription (STAT3) and endothelial nitric oxide synthase (eNOS) were determined.ResultsPrehypoxic exposure to 10% plasma obtained 6 h after helium inhalation decreased hypoxia-induced cell damage in HUVEC. Cav-1 knockdown in HUVEC abolished this effect.ConclusionsPlasma of healthy volunteers breathing helium protects HUVEC against hypoxic cell damage, possibly involving circulating Cav-1

    Complex band structure and plasmon lattice Green's function of a periodic metal-nanoparticle chain

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    When the surface plasmon resonance in a metal-nanoparticle chain is excited at one point, the response signal will generally decay down the chain due to absorption and radiation losses. The decay length is a key parameter in such plasmonic systems. By studying the plasmon lattice Green's function, we found that the decay length is generally governed by two exponential decay constants with phase factors corresponding to guided Bloch modes and one power-law decay with a phase factor corresponding to that of free space photons. The results show a high level of similarity between the absorptive and radiative decay channels. By analyzing the poles (and the corresponding residues) of the Green's function in a transformed complex reciprocal space, the dominant decay channel of the real-space Green's function is understood.Comment: 19 pages, 3 figure

    A dose-dependent plasma signature of the safety and immunogenicity of the rVSV-Ebola vaccine in Europe and Africa.

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    The 2014-2015 Ebola epidemic affected several African countries, claiming more than 11,000 lives and leaving thousands with ongoing sequelae. Safe and effective vaccines could prevent or limit future outbreaks. The recombinant vesicular stomatitis virus-vectored Zaire Ebola (rVSV-ZEBOV) vaccine has shown marked immunogenicity and efficacy in humans but is reactogenic at higher doses. To understand its effects, we examined plasma samples from 115 healthy volunteers from Geneva who received low-dose (LD) or high-dose (HD) vaccine or placebo. Fifteen plasma chemokines/cytokines were assessed at baseline and on days 1, 2 to 3, and 7 after injection. Significant increases in monocyte-mediated MCP-1/CCL2, MIP-1β/CCL4, IL-6, TNF-α, IL-1Ra, and IL-10 occurred on day 1. A signature explaining 68% of cytokine/chemokine vaccine-response variability was identified. Its score was higher in HD versus LD vaccinees and was associated positively with vaccine viremia and negatively with cytopenia. It was higher in vaccinees with injection-site pain, fever, myalgia, chills, and headache; higher scores reflected increasing severity. In contrast, HD vaccinees who subsequently developed arthritis had lower day 1 scores than other HD vaccinees. Vaccine dose did not influence the signature despite its influence on specific outcomes. The Geneva-derived signature associated strongly (ρ = 0.97) with that of a cohort of 75 vaccinees from a parallel trial in Lambaréné, Gabon. Its score in Geneva HD vaccinees with subsequent arthritis was significantly lower than that in Lambaréné HD vaccinees, none of whom experienced arthritis. This signature, which reveals monocytes' critical role in rVSV-ZEBOV immunogenicity and safety across doses and continents, should prove useful in assessments of other vaccines

    Depletion of RIPK3 or MLKL blocks TNF-driven necroptosis and switches towards a delayed RIPK1 kinase-dependent apoptosis

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    In human cells, the RIPK1-RIPK3-MLKL-PGAM5-Drp1 axis drives tumor necrosis factor (TNF)-induced necroptosis through mitochondrial fission, but whether this pathway is conserved among mammals is not known. To answer this question, we analyzed the presence and functionality of the reported necroptotic axis in mice. As in humans, knockdown of receptorinteracting kinase-3 (RIPK3) or mixed lineage kinase domain like (MLKL) blocks TNF-induced necroptosis in L929 fibrosarcoma cells. However, repression of either of these proteins did not protect the cells from death, but instead induced a switch from TNF-induced necroptosis to receptor-interacting kinase-1 (RIPK1) kinase-dependent apoptosis. In addition, although mitochondrial fission also occurs during TNF-induced necroptosis in L929 cells, we found that knockdown of phosphoglycerate mutase 5 (PGAM5) and dynamin 1 like protein (Drp1) did not markedly protect the cells from TNF-induced necroptosis. Depletion of Pink1, a reported interactor of both PGAM5 and Drp1, did not affect TNF-induced necroptosis. These results indicate that in these murine cells mitochondrial fission and Pink1 dependent processes, including Pink-Parkin dependent mitophagy, apparently do not promote necroptosis. Our data demonstrate that the core components of the necrosome (RIPK1, RIPK3 and MLKL) are crucial to induce TNF-dependent necroptosis both in human and in mouse cells, but the associated mechanisms may differ between the two species or cell types

    Coherent magnetic plasmon modes in a contacting gold nano-sphere chain on a gold Slab

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    A coupled magnetic resonator waveguide, composed of a contacting gold nanosphere chain on a gold slab, is proposed and investigated. A broadband coherent magnetic plasmon mode can be excited in this one dimensional nanostructure. By employing the Lagrangian formalism and the Fourier transform method, the dispersion properties of the wave vector and group velocity of the magnetic plasmon mode are investigated. Small group velocity can be obtained from this system which can be applied as subwavelength slow wave waveguides.Comment: 11pages, 5 figures, This work is published at Optics Express 19, 23782 (2011

    Design Principles for Plasmonic Nanoparticle Devices

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    For all applications of plasmonics to technology it is required to tailor the resonance to the optical system in question. This chapter gives an understanding of the design considerations for nanoparticles needed to tune the resonance. First the basic concepts of plasmonics are reviewed with a focus on the physics of nanoparticles. An introduction to the finite element method is given with emphasis on the suitability of the method to nanoplasmonic device simulation. The effects of nanoparticle shape on the spectral position and lineshape of the plasmonic resonance are discussed including retardation and surface curvature effects. The most technologically important plasmonic materials are assessed for device applicability and the importance of substrates in light scattering is explained. Finally the application of plasmonic nanoparticles to photovoltaic devices is discussed.Comment: 29 pages, 15 figures, part of an edited book: "Linear and Non-Linear Nanoplasmonics

    Detailed motility evaluation of boar semen and its predictive value for reproductive performance in sows

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    Reliable estimates of boar fertility potential from semen evaluation could be a valuable tool for boar selection. The aim of this study was to investigate the morphology and the detailed motility parameters of diluted boar semen and to relate these to their predictive value concerning conception and farrowing rate, litter size and the number of live born piglets. In addition, the optimal time for evaluation of the motility of preserved semen with respect to its predictive effect on fertility was determined. One hundred ejaculates from 38 boars were evaluated morphologically by eosin-nigrosin staining and different motility characteristics were assessed using Computer Assisted Semen Analysis (CASA). The motility was determined at 15, 45 and 120 minutes after incubation at 37 degrees C. The conception rate, farrowing rate, litter size and number of live born piglets were registered from 276 sows inseminated with these ejaculates. Different regression models were used to evaluate the predictive value of the semen characteristics on these fertility parameters, taking into account the effect of herd, parity and weaning to estrus interval. The motility characteristics of the spermatozoa varied significantly during the 15 to 120 minutes of incubation. The longer the incubation time, the more the velocity parameters along the actual cell path decreased, while the parameters of straightforward movement increased. The predictive value of individual semen parameters on conception and farrowing rate was very small. The predictive value of certain associations of different semen parameters, on the other hand, was significant. The percentage of motile spermatozoa had a significant (P<0.05) and positive effect on the total number of piglets born (litter size) and on the number of live born piglets, independent of the time of measurement (X-2 0.38-1.00 and 0.41-1.00, respectively). Accurate evaluation of the motility of a semen dose is therefore imperative for estimating its predictive value relating to fertility. In conclusion, since the time of evaluation after warming the samples significantly influences the motility parameters, CASA measurement should be done when the cells are completely acclimatized to 37 degrees C. On the basis of the available data, a 45 min incubation period appeared to be sufficient. The percentage of motile spermatozoa, as assessed by CASA on diluted semen, offers detailed predictive information regarding litter size, irrespective of the time of measurement

    Разработка приспособления для сборки и сварки балки навески

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    Цель работы –разработка приспособления для сборки и сварки балки навески, которое позволит ускорить процесс подготовки деталей перед сваркой, будет иметь возможность поворота изделия и доступ к сварке со всех сторон. Проведен технико-экономический анализ процесса сборки и сварки балки навески. Дано обоснование эффективности предлагаемого приспособления и малый срок его окупаемости.The object of this study is to build technology and welding hinge beams. Purpose - improving the technology of assembling and welding of sample beams, so as to speed up the process of preparing the parts prior to welding, and have the ability to rotate the product and access to welding on all sides. Spend a technical and economic analysis of the process of assembly and welding hinge beams. The substantiation of the effectiveness of the proposed adaptations and short term payback

    Estimating HIV incidence and the undiagnosed HIV population in the European Union / European economic area

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    ECDC HIV/AIDS Surveillance and Dublin Declaration Networks participants: Portugal - Helena Cortes Martins (INSA).Each year, about 30,000 people are newly diagnosed with HIV in the 31 countries of the European Union/European Economic Area (EU/EEA). We aimed to estimate the number of people living with undiagnosed HIV in the entire EU/EEA and in four sub-regions.N/

    Cross-cultural psychometric assessment of an appetite questionnaire for patients with cancer

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    Objective: To evaluate the psychometric properties, along with cross-cultural invariance analysis, of the Cancer Appetite and Symptom Questionnaire (CASQ). Method: Data from 555 United Kingdom (UK) cancer patients were used to evaluate the psychometric properties of the CASQ. Construct validity was assessed through factorial and convergent validity. We conducted a confirmatory factor analysis using as indices the chi-square ratio by degrees of freedom (χ2/df), the comparative fit index (CFI), the goodness of fit index (GFI), and the root mean square error of approximation (RMSEA). Convergent validity was estimated by the items’ average variance extracted (AVE). Reliability was estimated by composite reliability and internal consistency. Factorial invariance analysis of the CASQ was evaluated by multigroup analysis (∆χ2) using the UK and Brazilian samples. Results: All items showed adequate psychometric sensitivity in the UK sample. One item was removed and four correlations were included between errors with an appropriate fit of the model (χ2/df = 2.674, CFI = 0.966, GFI = 0.964, RMSEA = 0.055). The reliability of the CASQ was adequate and the convergent validity was low. The factorial structure of the CASQ differed across countries, and a lack of measurement invariance for the two countries was observed (λ: ∆χ2 = 64.008, p < 0.001; i: ∆χ2 = 3515.047, p < 0.001; Res: ∆χ2 = 4452.504, p < 0.001). Conclusion: The CASQ showed adequate psychometric properties in the UK sample. The ability to estimate loss of appetite and the presence of symptoms was different between UK and Brazilian patients
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