268 research outputs found

    Some Consequences of Noncommutative Worldsheet of Superstring

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    In this paper some properties of the superstring with noncommutative worldsheet are studied. We study the noncommutativity of the spacetime, generalization of the Poincar\'e symmetry of the superstring, the changes of the metric, antisymmetric tensor and dilaton.Comment: 11 pages, Latex, no figure, a new action and some references have been adde

    Two Moving-Angled 1-Branes with Electric Fields in a Partially Compact Spacetime

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    In this article we consider two m1m1-branes at angle in the presence of the background electric fields, in a partially compact spacetime. The branes have motions along a common direction that is perpendicular to both of them. Using the boundary state formalism, we calculate their interaction amplitude. Some special cases of this interaction will be studied in detail.Comment: 10 pages, no figure, Late

    Should we abandon the APTT for monitoring unfractionated heparin?

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    INTRODUCTION: The activated partial thromboplastin time (APTT) is commonly used to monitor unfractionated heparin (UFH) but may not accurately measure the amount of heparin present. The anti-Xa assay is less susceptible to confounding factors and may be a better assay for this purpose. MATERIALS AND METHODS: The validity of the APTT for monitoring UFH was assessed by comparing with an anti-Xa assay on 3543 samples from 475 patients (infants [n=165], children 1-15years [n=60] and adults [n=250]) receiving treatment dose UFH. RESULTS: Overall concordance was poor. The highest concordance (66%; 168/254) was seen in children. Concordance (51.8%) or discordance (48.4%) was almost equal in adult patients. Among adult patients whose anti-Xa level was within 0.3-0.7IU/mL, only 38% had an APTT in the therapeutic range whilst 56% were below and 6% were above therapeutic range. Children and adult patients with anti-Xa of 0.3-0.7IU/mL but sub- therapeutic APTT had significantly higher fibrinogen levels compared to those with therapeutic or supra-therapeutic APTT. CONCLUSIONS: When the anti-Xa level was 0.3-0.7IU/mL, the majority of samples from infants demonstrated a supra-therapeutic APTT, whilst adults tended to have a sub-therapeutic APTT. This may lead to under anticoagulation in infants or over anticoagulation in adults with risk of bleeding if APTT is used to monitor UFH. These results further strengthen existing evidence of the limitation of APTT in monitoring UFH. Discordance of APTT and anti-Xa level in adults and children may be due to elevation of fibrinogen level

    Schwinger Effect in Non-parallel D1-branes: A Path Integral Approach

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    We study the Schwinger effect in a system of non-parallel D1-branes for the bosonic strings using the path integral formalism. We drive the string pair creation rate by calculating the one loop vacuum amplitude of the setup in presence of the background electric filed defined along one of the D1-branes. We find an angle dependent minimum value for the background field and show that the decaying of vacuum into string pairs takes place for the field above this value. It is shown that in θπ2\theta\rightarrow\frac{\pi}{2} limit the vacuum becomes stable and thus no pair creation occurs

    Deep penetrating nevus: a case report and brief literature review

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    BACKGROUND -: Deep penetrating nevus (DPN) is a distinct variant of melanocytic nevus and remains a histopathologic challenge to pathologists because of its resemblance to blue nevus, malignant melanoma, pigmented Spitz nevus, and congenital melanocytic nevus. It often goes unrecognized due to its relative rarity. CASE PRESENTATION -: Here we report a case of DPN of the left anterior leg in a 51-year old female. A brief review of the literature shows that these lesions have a distinct growth pattern and cellular morphology that can differentiate these lesions from other entities including malignant melanoma. CONCLUSION -: It is important to recognize these features because DPN carries a better prognosis than malignant melanoma

    Haemobilia: a rare cause of gastrointestinal bleeding

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    Iatrogenic injury to hepatic duct leading to pseudoaneurysm and haemobilia can occur following laparoscopic cholecystectomy. We report a case of a 60 years old man presenting with haematemesis found to have pseudoaneurysm of accessory hepatic artery 4 months after laparoscopic cholecystectomy. Diagnosis was made by computed tomography (CT) scan followed by celiac and mesenteric artery angiogram. The bleeding was successfully treated with coil embolization

    Noncommutative Decrumpling Inflation and Running of the Spectral Index

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    We present a new inflation model, known as noncommutative decrumpling inflation, in which space has noncommutative geometry with time variability of the number of spatial dimensions. Within the framework of noncommutative decrumpling inflation, we compute both the spectral index and its running. Our results show that the effects of both time variability of the number of spatial dimensions and noncommutative geometry on the spectral index and its running. Two classes of examples have been studied and comparisons made with the standard slow-roll formulae. We conclude that the effects of noncommutative geometry on the spectral index and its running are much smaller than the effects of time variability of spatial dimensions.Comment: 15 pages, accepted for publication in Int.J.Mod.Phys.

    Imaging angiogenesis in atherosclerosis in large arteries with 68Ga-NODAGA-RGD PET/CT: relationship with clinical atherosclerotic cardiovascular disease.

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    Integrin alpha-V-beta-3 (αvβ3) pathway is involved in intraplaque angiogenesis and inflammation and represents a promising target for molecular imaging in cardiovascular diseases such as atherosclerosis. The aim of this study was to assess the clinical correlates of arterial wall accumulation of <sup>68</sup> Ga-NODAGA-RGD, a specific α <sub>v</sub> β <sub>3</sub> integrin ligand for PET. The data of 44 patients who underwent <sup>68</sup> Ga-NODAGA-RGD PET/CT scans were retrospectively analyzed. Tracer accumulation in the vessel wall of major arteries was analyzed semi-quantitatively by blood-pool-corrected target-to-background ratios. Tracer uptake was compared with clinically documented atherosclerotic cardiovascular disease, cardiovascular risk factors and calcified plaque burden. Data were compared using the Mann-Whitney U test, Pearson correlation and Spearman correlation. <sup>68</sup> Ga-NODAGA-RGD arterial uptake was significantly higher in patients with previous clinically documented atherosclerotic cardiovascular disease (mean TBR 2.44 [2.03-2.55] vs. 1.81 [1.56-1.96], p = 0.001) and showed a significant correlation with prior cardiovascular or cerebrovascular event (r = 0.33, p = 0.027), BMI (ρ = 0.38, p = 0.01), plaque burden (ρ = 0.31, p = 0.04) and hypercholesterolemia (r = 0.31, p = 0.04). <sup>68</sup> Ga-NODAGA-RGD holds promise as a non-invasive marker of disease activity in atherosclerosis, providing information about intraplaque angiogenesis

    Moving Branes with Background Massless and Tachyon Fields in the Compact Spacetime

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    In this article we shall obtain the boundary state associated with a moving DpDp-brane in the presence of the Kalb-Ramond field BμνB_{\mu\nu}, an internal U(1) gauge field AαA_{\alpha} and a tachyon field, in the compact spacetime. According to this state, properties of the brane and a closed string, with mixed boundary conditions emitted from it, will be obtained. Using this boundary state we calculate the interaction amplitude of two moving Dp1Dp_{1} and Dp2Dp_{2}-branes with above background fields in a partially compact spacetime. They are parallel or perpendicular to each other. Properties of the interaction amplitude will be analyzed and contribution of the massless states to the interaction will be extracted.Comment: 13 pages, Latex, no figur
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