2,131 research outputs found

    The traumatized ischiopubic synchondrosis: a rare cause of acute hip pain

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    # The Author(s) 2011. This article is published with open access at Springerlink.co

    Robust H-2 static output feedback design starting from a parameter-dependent state feedback controller for time-invariant discrete-time polytopic systems

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This paper investigates the problem of computing robust H-2 static output feedback controllers for discrete-time uncertain linear systems with time-invariant parameters lying in polytopic domains. A two stages design procedure based on linear matrix inequalities is proposed as the main contribution. First, a parameter-dependent state feedback controller is synthesized and the resulting gains are used as an input condition for the second stage, which designs the desired robust static output feedback controller with an H-2 guaranteed cost. The conditions are based on parameter-dependent Lyapunov functions and, differently from most of existing approaches, can also cope with uncertainties in the output control matrix. Numerical examples, including a mass spring system, illustrate the advantages of the proposed procedure when compared with other methods available in the literature. Copyright (C) 2009 John Wiley & Sons, Ltd.321113Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Pseudomonas aeruginosa toxin ExoU induces a PAF-dependent impairment of alveolar fibrin turnover secondary to enhanced activation of coagulation and increased expression of plasminogen activator inhibitor-1 in the course of mice pneumosepsis

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    <p>Abstract</p> <p>Background</p> <p>ExoU, a <it>Pseudomonas aeruginosa </it>cytotoxin with phospholipase A<sub>2 </sub>activity, was shown to induce vascular hyperpermeability and thrombus formation in a murine model of pneumosepsis. In this study, we investigated the toxin ability to induce alterations in pulmonary fibrinolysis and the contribution of the platelet activating factor (PAF) in the ExoU-induced overexpression of plasminogen activator inhibitor-1 (PAI-1).</p> <p>Methods</p> <p>Mice were intratracheally instilled with the ExoU producing PA103 <it>P. aeruginosa </it>or its mutant with deletion of the <it>exoU </it>gene. After 24 h, animal bronchoalveolar lavage fluids (BALF) were analyzed and lung sections were submitted to fibrin and PAI-1 immunohistochemical localization. Supernatants from A549 airway epithelial cells and THP-1 macrophage cultures infected with both bacterial strains were also analyzed at 24 h post-infection.</p> <p>Results</p> <p>In PA103-infected mice, but not in control animals or in mice infected with the bacterial mutant, extensive fibrin deposition was detected in lung parenchyma and microvasculature whereas mice BALF exhibited elevated tissue factor-dependent procoagulant activity and PAI-1 concentration. ExoU-triggered PAI-1 overexpression was confirmed by immunohistochemistry. In <it>in vitro </it>assays, PA103-infected A549 cells exhibited overexpression of PAI-1 mRNA. Increased concentration of PAI-1 protein was detected in both A549 and THP-1 culture supernatants. Mice treatment with a PAF antagonist prior to PA103 infection reduced significantly PAI-1 concentrations in mice BALF. Similarly, A549 cell treatment with an antibody against PAF receptor significantly reduced PAI-1 mRNA expression and PAI-1 concentrations in cell supernatants, respectively.</p> <p>Conclusion</p> <p>ExoU was shown to induce disturbed fibrin turnover, secondary to enhanced procoagulant and antifibrinolytic activity during <it>P. aeruginosa </it>pneumosepsis, by a PAF-dependent mechanism. Besides its possible pathophysiological relevance, <it>in vitro </it>detection of e<it>xoU </it>gene in bacterial clinical isolates warrants investigation as a predictor of outcome of patients with <it>P. aeruginosa </it>pneumonia/sepsis and as a marker to guide treatment strategies.</p

    Finding and tracing human MSC in 3D microenvironments with the photoconvertible proteinDendra2

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    Mesenchymal Stem/Stromal Cells (MSC) are a promising cell type for cell-based therapies - from tissue regeneration to treatment of autoimmune diseases - due to their capacity to migrate to damaged tissues, to differentiate in different lineages and to their immunomodulatory and paracrine properties. Here, a simple and reliable imaging technique was developed to study MSC dynamical behavior in natural and bioengineered 3D matrices. Human MSC were transfected to express a fluorescent photoswitchable protein, Dendra2, which was used to highlight and follow the same group of cells for more than seven days, even if removed from the microscope to the incubator. This strategy provided reliable tracking in 3D microenvironments with different properties, including the hydrogels Matrigel and alginate as well as chitosan porous scaffolds. Comparison of cells mobility within matrices with tuned physicochemical properties revealed that MSC embedded in Matrigel migrated 64% more with 5.2 mg protein/mL than with 9.6 mg/mL and that MSC embedded in RGD-alginate migrated 51% faster with 1% polymer concentration than in 2% RGD-alginate. This platform thus provides a straightforward approach to characterize MSC dynamics in 3D and has applications in the field of stem cell biology and for the development of biomaterials for tissue regeneration

    The Detection of Hot Cores and Complex Organic Molecules in the Large Magellanic Cloud

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    We report the first extragalactic detection of the complex organic molecules (COMs) dimethyl ether (CH3OCH3) and methyl formate (CH3OCHO) with the Atacama Large Millimeter/submillimeter Array (ALMA). These COMs, together with their parent species methanol (CH3OH), were detected toward two 1.3 mm continuum sources in the N 113 star-forming region in the low-metallicity Large Magellanic Cloud (LMC). Rotational temperatures (Trot∼130{T}_{\mathrm{rot}}\sim 130 K) and total column densities (Nrot∼1016{N}_{\mathrm{rot}}\sim {10}^{16} cm−2) have been calculated for each source based on multiple transitions of CH3OH. We present the ALMA molecular emission maps for COMs and measured abundances for all detected species. The physical and chemical properties of two sources with COMs detection, and the association with H2O and OH maser emission, indicate that they are hot cores. The fractional abundances of COMs scaled by a factor of 2.5 to account for the lower metallicity in the LMC are comparable to those found at the lower end of the range in Galactic hot cores. Our results have important implications for studies of organic chemistry at higher redshift

    Surveying the agents of galaxy evolution in the tidally stripped, low metallicity small Magellanic cloud (SAGE-SMC), III: young stellar objects

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    The Spitzer Space Telescope Legacy Program SAGE-SMC allows global studies of resolved stellar populations in the SMC in a different environment than our Galaxy. Using the SAGE-SMC IRAC (3.6-8.0 mu m) and MIPS (24 and 70 mu m) catalogs and images combined with near-infrared (JHK(s)) and optical (UBVI) data, we identified a population of similar to 1000 intermediate-to high-mass young stellar objects (YSOs) in the SMC (three times more than previously known). Our method of identifying YSO candidates builds on the method developed for the Large Magellanic Cloud by Whitney et al. with improvements based on what we learned from our subsequent studies and techniques described in the literature. We perform (1) color-magnitude cuts based on five color-magnitude diagrams (CMDs), (2) visual inspection of multi-wavelength images, and (3) spectral energy distribution (SED) fitting with YSO models. For each YSO candidate, we use its photometry to calculate a measure of our confidence that the source is not a non-YSO contaminant, but rather a true YSO, based on the source's location in the color-magnitude space with respect to non-YSOs. We use this CMD score and the SED fitting results to define two classes of sources: high-reliability YSO candidates and possible YSO candidates. We found that, due to polycyclic aromatic hydrocarbon emission, about half of our sources have [3.6]-[4.5] and [4.5]-[5.8] colors not predicted by previous YSO models. The YSO candidates are spatially correlated with gas tracers

    Dengue fever: a post-epidemic sero-epidemiological survey in an urban setting at a northwestern county of S. Paulo State - Brazil

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    Objective The objective of this study was to evaluate the real size of the epidemics registered in thr urban area of the county of Santa Barbara D'Oeste, SP Brazil, from April to June, 1995. The measurement of the epidemiological validity of the official surveillance system criteria and its positive predicted value It were adopted as specific goals. Methods A sero-epidemiological sun,ey was carried out over a sample of 1,113 sera from citizens of Santa Barbara D'Oeste, through a systematic random sampling of houses, five months after the end of the epidemics. Infection rates were compared with the infestation indexes by Aedes aegipty and the notified cases amongst the county sections. The importance of submitting patients with clinical suspicion of dengue to laboratory rests was discussed. Results and Discussion it was found that infection rates by dengue virus varied in the same direction and proportion as the presence of Aedes aegipty larvae reported by the 'Breteau Index', as well as the number of cases,reported by the official notifiable diseases surveillance system during the epidemics. A prevalence of 630 by 100 thousand inhabitants was found, a 15-fold rate when compared to rite laboratory positive sera from cases detected by the surveillance system during the epidemics. A retrospective comparison with the surveillance reports, using serological results as a gold standard, also showed that the majority of dengue specific serum-positive individuals were not detected during the epidemics. otherwise cases that did not present serological reaction were notified exhibiting a low positive predictive value of clinical diagnosis (15,6).33656657
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