355 research outputs found

    Evaluation of PECAM-1 and p38 MAPK expressions in cerebellum tissue of rats treated with caffeic acid phenethyl ester: a biochemical and immunohistochemical study

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    Background: This study aimed to investigate the antioxidative and anti-inflam- matory effects of caffeic acid phenethyl ester (CAPE) on damage caused to cere- bellum tissue by diffuse traumatic head trauma via biochemical, histopathologic, and immuno-histochemical methods.  Materials and methods: Male Sprague-Dawley (300–350 g) rats were subjected to traumatic brain injury with a weight-drop device (300 g/1 m weight-height im- pact). Twenty-four adult rats were randomly divided into three equal groups of 8, including a control group, traumatic brain injury (TBI) group, and TBI + CAPE treatment group (10 ÎŒmoL/kg/i.p.). Cerebellum tissue samples taken from anterior lobe from all rats were taken 7 days after traumatic injury and were subjected to biochemical and histopathological analysis, as well as immunohistochemical ana- lysis for platelet endothelial cell adhesion molecule-1 (PECAM-1) and phosphate 38-mitogen-activated protein kinase (p38 MAPK).  Results: In the TBI group, the granular layer had dilatation and haemorrhage in the capillary vessels and inflammatory cell infiltration around the periphery of the blood vessels. In the TBI + CAPE group, the small capillaries in the white matter were slightly dilated, there were no inflammatory cells, and dense chromatin/ granular cells were observed in the granular layer. Also in the TBI + CAPE group, the Purkinje cells of the ganglion cell layer had ovoid nuclei, were chromatin- -rich, and their extensions protruded to the molecular layer. CAPE is thought to regulate inflammation, cell damage, and angiogenetic development by affecting the PECAM-1 and p38 MAPK proteins.  Conclusions: These proteins are key modulators of endothelial integrity and neuroinflammation in vessels in response to endothelial damage as well as of the proinflammatory response in the cerebellum in response to traumatic damage.

    Expression of vascular endothelial growth factor and glial fibrillary acidic protein in a rat model of traumatic brain injury treated with honokiol: a biochemical and immunohistochemical study

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    Background: Traumatic brain injury (TBI) leads to neuronal damage and neurological dysfunction. The aim of our study was to investigate the antioxidative effect of honokiol on TBI in rats with biochemical, histopathological and immunohistochemical methods. Materials and methods: Sprague–Dawley rats were subjected to TBI with a weight-drop device using 300 g/1 m weight/height impact. Forty-five rats were divided into three groups as control group, TBI group and TBI + honokiol group (5 mg/kg/day, i.p.). Honokiol (5 mg/kg) dissolved in dimethyl sulfoxide (DMSO) was intraperitoneally administered to rats for 7 days after the trauma. At the end of experiment, blood samples were taken from the animals and analysed with various biochemical markers. Results: Histopathological examination of the trauma group revealed some degenerated pyramidal cells, dilatation and congestion in blood vessels, hyperplasia in endothelial cells, inflammatory cell infiltration around the vein and disruptions in glial extensions. In TBI + honokiol group, pyramidal neurons showed a decrease in degeneration, slight dilatation in blood vessels, improvement of endothelial cells towards the lumen, and reduction of inflammatory cells in the vessel. In TBI + honokiol group, vascular endothelial growth factor expression was positive in the endothelial and few inflammatory cells of the mildly dilated blood vessels. In the blood brain barrier deteriorated after trauma, it was observed that the glial foot processes were positive expression and extended to the endothelial cells in the TBI + honokiol group. Conclusions: Glial fibrillary acidic protein expression showed a positive reaction in these processes. Considering the important role of antioxidants and inflammatory responses in cerebral damage induced by traumatic head injury, honokiol is thought to be important in decreasing lipid peroxidation, protecting the membrane structure of blood brain barrier, degeneration of neurons and glial cells

    Incremental Distance Transforms (IDT)

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    A new generic scheme for incremental implementations of distance transforms (DT) is presented: Incremental Distance Transforms (IDT). This scheme is applied on the cityblock, Chamfer, and three recent exact Euclidean DT (E2DT). A benchmark shows that for all five DT, the incremental implementation results in a significant speedup: 3.4×−10×. However, significant differences (i.e., up to 12.5×) among the DT remain present. The FEED transform, one of the recent E2DT, even showed to be faster than both city-block and Chamfer DT. So, through a very efficient incremental processing scheme for DT, a relief is found for E2DT’s computational burden

    A taxonomic study of the genus Fibigia Medik. (Brassicaceae)

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    In this study, Purpureae A.Duran and Ö.Çetin sect. nov. is described under the genus Fibigia Medik. The taxa of the genus were revised under the sections Fibigia and Purpureae. Fibigia clypeata (L.) Medik was classified as F. clypeata (L.) Medik subsp. clypeata and subsp. anatolica A.Duran & Tustas subsp. nov., and Fibigia eriocarpa (DC.) Boiss. was rearranged as F. clypeata (L.) Medik subsp. clypeata var. eriocarpa in Turkish Flora. The infrageneric and subgeneric keys were revised. Seed and pollen surface ornamentations were studied by scanning electron microscopy (SEM). The pollens examined have tricolpate aperture type and reticulate surface ornamentation. Seed surface ornamentation was reticulate. The taxa of the genus Fibigia have a diploid chromosome number of 2n=16. Karyotype analyses of the taxa were carried out for the first time. It was found that each taxon differed in chromosome morphology.Key words: Fibigia, morphology, pollen, scanning electron microscopy (SEM), new taxa, Turkey

    Feynman-Schwinger representation approach to nonperturbative physics

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    The Feynman-Schwinger representation provides a convenient framework for the cal culation of nonperturbative propagators. In this paper we first investigate an analytically solvable case, namely the scalar QED in 0+1 dimension. With this toy model we illustrate how the formalism works. The analytic result for the self energy is compared with the perturbative result. Next, using a χ2ϕ\chi^2\phi interaction, we discuss the regularization of various divergences encountered in this formalism. The ultraviolet divergence, which is common in standard perturbative field theory applications, is removed by using a Pauli-Villars regularization. We show that the divergence associated with large values of Feynman-Schwinger parameter ss is spurious and it can be avoided by using an imaginary Feynman parameter isis.Comment: 26 pages, 9 figures, minor correctio

    Fourth Generation Pseudoscalar Quarkonium Production and Observability at Hadron Colliders

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    The pseudoscalar quarkonium state, eta_4 1^S_0, formed by the Standard Model (SM) fourth generation quarks, is the best candidate among the fourth generation quarkonia to be produced at the LHC and VLHC. The production of this J^{PC} = 0^{-+} resonance is discussed and the background processes are studied to obtain the integrated luminosity limits for the discovery, depending on its mass.Comment: 13 pages, 4 figures, 5 table

    The effect of thrombolytic therapy on QT dispersion in acute myocardial infarction and its role in the prediction of reperfusion arrhythmias

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    Purpose: We aimed to determine the effect of intravenous thrombolytic therapy on QT dispersion (QTd) and its role in the prediction of reperfusion arrhythmias.Materials and Methods: Twenty patients with acute myocardial infarction (MI) were enrolled in the study. Measurements of QTd were carried out  prior to thrombolytic therapy and before discharge. The patients were examined for ventricular arrhythmias with 24‑h Holter electrocardiography monitoring after treatment and the relationship between ventricular arrhythmias and the QTd values in the early phase of MI was investigated.Results: The values of QTd were significantly higher during the early phase of MI (60 ± 5.32 ms) than those in the late phase (53.35 ± 4.07 ms) (P = 0.032). There was no correlation between isolated, bigeminal, trigeminal and total ventricular premature beats, accelerated idioventricular rhythm (AIVR) with QTd values. However, the patients with sustained ventricular tachycardia (VT), prolonged VT and sustained AIVR had higher corrected QTd (92 ms1/2, 97.8 ms1/2, 81.7 ms1/2, respectively) than the patients without these arrhythmias (74 ms1/2, 56.3 ms1/2, 58.28 ms1/2,  respectively) (P = 0.022, 0.013, 0.018).Conclusion: The values of QTd may be significantly reduced in the 1st week of acute MI and measurement of QTd in the early phase of MI may have a correlation with the following reperfusion arrhythmias: Sustained VT, prolonged VT and AIVR.Key words: Arrhythmia, myocardial infarction, QT dispersion, reperfusion, thrombolytic therap

    Active control of focal length and beam deflection in a metallic nano-slit array lens with multiple sources

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    We propose a surface plasmon-polariton based nano-rod array lens structure that incorporates two additional lateral input channels, with the ability to control the focal length and the deflection of the transmitted beam through the lens actively by the intensity of the channel sources. We demonstrate by numerical simulations that, applying the sources with the same intensity can change the focal point and the beam waist, whereas unequal intensities generate an asymmetric field profile in the nano-rod array inducing an off-axis beam deflection.Comment: 4 pages, 5 figure

    Arbitrage and deflators in illiquid markets

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    This paper presents a stochastic model for discrete-time trading in financial markets where trading costs are given by convex cost functions and portfolios are constrained by convex sets. The model does not assume the existence of a cash account/numeraire. In addition to classical frictionless markets and markets with transaction costs or bid-ask spreads, our framework covers markets with nonlinear illiquidity effects for large instantaneous trades. In the presence of nonlinearities, the classical notion of arbitrage turns out to have two equally meaningful generalizations, a marginal and a scalable one. We study their relations to state price deflators by analyzing two auxiliary market models describing the local and global behavior of the cost functions and constraints
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