1,406 research outputs found

    Nondipole signatures in ionization

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    A general method for solving numerically the time-dependent Schr\"odinger equation, that is based on the Suzuki-Trotter scheme with the split-step Fourier approach, is introduced. The method relies on a Hamiltonian decomposition, where except of the components depending exclusively on the momentum or on the position operators, there are also terms depending on both momentum and position operators in particular configurations. We demonstrate that, for as long as the latter does not depend on noncommuting coordinates of the momentum and position operators, nondipole effects in laser-matter interactions can be studied without applying extra unitary operations. Specifically, we analyze the effect of nondipole corrections in ionization of a two-dimensional hydrogen atom for low- and high-frequency pulses. In the former case, the electron wave packet dynamics is dominated by rescattering processes within the laser pulse, leading to the high-order harmonic generation. We illustrate that harmonics of even orders are generated in the direction of the laser field polarization. On the contrary, for high-frequency pulses, such rescattering processes can be neglected. We demonstrate that a significant portion of the low-energy photoelectrons is detected opposite to the laser pulse propagation direction as a consequence of their post-pulse wave packet spreading and interaction with the parent ion.Comment: 9 figure

    T-lymphocyte-rich thymoma and myasthenia gravis in a Siberian tiger (Panthera tigris altaica)

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    A 10-year-old captive male Siberian tiger (Panthera tigris altaica) presented with acute onset collapse, vomiting and dyspnoea, preceded by a 6-month period of progressive muscle wasting. Following humane destruction, post-mortem examination revealed a large multilobulated mass in the cranial mediastinum, which was diagnosed as a T-lymphocyte-rich thymoma with the aid of immunohistochemistry. Retrospective serology for acetylcholine receptor antibodies (titre 3.90 nmol/l) confirmed a diagnosis of thymoma-associated myasthenia gravis. Thymomas are reported rarely in wild carnivores, but when detected they appear to be similar in morphology to those seen in domestic carnivores and may also be accompanied by paraneoplastic syndromes. The clinical signs of myasthenia gravis in the tiger were consistent with those reported in cats and dogs and the condition is proposed as an important differential diagnosis for generalized weakness in captive Felidae

    A new carbohydrate-active oligosaccharide dehydratase is involved in the degradation of ulvan

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    Marine algae catalyze half of all global photosynthetic production of carbohydrates. Owing to their fast growth rates, Ulva spp. rapidly produce substantial amounts of carbohydrate-rich biomass and represent an emerging renewable energy and carbon resource. Their major cell wall polysaccharide is the anionic carbohydrate ulvan. Here, we describe a new enzymatic degradation pathway of the marine bacterium Formosa agariphila for ulvan oligosaccharides involving unsaturated uronic acid at the nonreducing end linked to rhamnose-3-sulfate and glucuronic or iduronic acid (Delta-Rha3S-GlcA/IdoA-Rha3S). Notably, we discovered a new dehydratase (P29_PDnc) acting on the nonreducing end of ulvan oligosaccharides, i.e., GlcA/IdoARha3S, forming the aforementioned unsaturated uronic acid residue. This residue represents the substrate for GH105 glycoside hydrolases, which complements the enzymatic degradation pathway including one ulvan lyase, one multimodular sulfatase, three glycoside hydrolases, and the dehydratase P29_PDnc, the latter being described for the first time. Our research thus shows that the oligosaccharide dehydratase is involved in the degradation of carboxylated polysaccharide

    Influencia del agua en la esterificación enzimática de ketoprofeno racémico con etanol sin co-solvente agregado

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    Las lipasas son las enzimas más comúnmente usadas para producir dexketoprofeno mediante resolución cinética. Este isómero es farmacológicamente activo, por lo que su obtención de forma pura disminuiría los efectos adversos del AINE

    Exile Vol. XLIII No. 2

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    41st Year Title Page i Epigraphy by Ezra Pound ii Table of Contents iii / Contributors\u27 Notes 70-71 Editorial Board 72-73 ART Untitled by Kari Hernquist \u2799 4 Talking Out my Window by Heather Trabert \u2797 13 Renamed I by Ben Blake \u2797 18 photo paint by alex e. blazer \u2797 23 Butterfly by Mary Donnelley \u2797 32 unabridged by alex e. blazer \u2797 37 Holding Me In by Heather Trabert \u2797 43 Untitled by Kari Hernquist \u2797 55 Untitled by Camille Gammon-Hittelman \u2799 61 Stars by Mary Donnelley \u2797 69 POETRY Victrola by erin c. malone \u2799 1 All by Kellam Ayres \u2797 2-3 curtailed sun in the net by alex e. blazer \u2797 5 the weaker sex by Bekah Taylor \u2700 6 A poem concerning a silent manifesto by Colin Bossen \u2798 14 Father by Alison Stine \u2700 15 Vacant by Sean Boyle \u2700 16 Ecstasy by Amy spears \u2798 17 Seven Haikus by Jen Suster \u2797 21 Pages from a Diary by Trish Klei \u2797 22 Watching an Ageless Woman and an Ancient Trade by Heather Trabert \u2797 24-25 Still Waters by Jay Brandeis \u2799 26 just shy of freedom by Sean Boyle \u2700 36 [Touch the mothers you never knew] by Heather Trabert \u2797 38 Fishing for Meaning by Bekah Taylor \u2700 39 the novel by Sara Brown \u2799 40-41 annihilation by erin c. malone \u2799 42 Upon Enlistment by Trish Klei \u2797 44 the expatriate by erin c. malone \u2799 47 Rockettes by Trish Klei \u2797 48-49 Abstraction by Colin Bossen \u2798 54 always kinesis by alex e. blazer \u2797 56-57 Lily by Alison Stine \u2700 58-59 Falling In by Bekah Taylor \u2700 60 this bird has flown by paul durica \u2700 62-63 exfoliating some sun by alex e. blazer \u2797 64 Liberation: May 8, 1945 by Jen suster \u2797 65 PROSE Journal: 12 December 1996 through 15 January 1997 by Lynn Tramonte \u2798 7-12 Ash by paul durica \u2700 19-20 Birdhouse by Tyler Smith \u2797 27-35 Party in December by paul durica \u2700 45-46 Smoke Circles by Alison Stine \u2700 50-53 Seal by Lynn Tramonte \u2798 66-68 All submissions are reviewed on an anonymous basis, and all editorial decisions are shared equally among the members of the Editorial Board. -72 Cover art Toy Child by Ben Blake \u2797 -7

    Inter-Observer Variation in the Pathologic Identification of Minimal Extrathyroidal Extension in Papillary Thyroid Carcinoma

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    Background: Extrathyroidal extension (ETE) is a significant prognostic factor in papillary thyroid carcinoma (PTC). Minimal extrathyroidal extension (mETE) is characterized by involvement of the sternothyroid muscle or perithyroid soft tissue, and is generally identified by light microscope examination. Patients with mETE, identified pathologically, are automatically upstaged to pT3. However, the prognostic implications of mETE have been a source of controversy in the literature. Moreover, there is also controversy surrounding the identification of mETE on pathological specimens. The objective of this study was to determine the level of agreement among expert pathologists in the identification of mETE in PTC cases. Methods: Eleven expert pathologists from the United States, Italy, and Canada were asked to perform a review of 69 scanned slides of representative permanent sections of PTC specimens. Each slide was evaluated for the presence of mETE. The pathologists were also asked to list the criteria they use to identify mETE. Results: The overall strength of agreement for identifying mETE was slight (??=?0.14). Inter-pathologist agreement was best for perithyroidal skeletal muscle involvement (??=?0.46, moderate agreement) and worst for invasion around thick-walled vascular structures (??=?0.02, slight agreement). In addition, there was disagreement over the constellation of histologic features that are diagnostic for mETE, which affected overall agreement for diagnosing mETE. Conclusions: Overall agreement for the identification of mETE is poor. Disagreement is a result of both variation in individual pathologists' interpretations of specimens and disagreement on the histologic criteria for mETE. Thus, the utility of mETE in staging and treatment of PTC is brought into question. The lack of concordance may explain the apparent lack of agreement regarding the prognostic significance of this pathologic feature.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140271/1/thy.2015.0508.pd

    Inter-Observer Variation in the Pathologic Identification of Extranodal Extension in Nodal Metastasis from Papillary Thyroid Carcinoma

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    Background: Extranodal extension (ENE) in lymph node metastases has been shown to worsen the prognosis of papillary thyroid cancer (PTC). Despite the clinical significance of ENE, there are no stringent criteria for its microscopic diagnosis, and its identification is subject to inter-observer variability. The objective of this study was to determine the level of agreement among expert pathologists in the identification of ENE in PTC cases. Methods: Eleven expert pathologists from the United States, Italy, and Canada were asked to review 61 scanned slides of representative permanent sections of PTC specimens from Mount Sinai Beth Israel Medical Center in New York. Each slide was evaluated for the presence of ENE. The pathologists were also asked to report the criteria they use to identify ENE. Results: The overall strength of agreement in identifying ENE was only fair (??=?0.35), and the proportion of observed agreement was 0.68. The proportions of observed agreement for the identification of perinodal structures (fat, nerve, skeletal, and thick-walled vessel involvement) ranged from 0.61 to 0.997. Conclusions: Overall agreement for the identification of ENE is poor. The lack of agreement results from both variation in pathologists' identification of features and disagreement on the histologic criteria for ENE. This lack of concordance may help explain some of the discordant information regarding prognosis in clinical studies when this feature is identified.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140272/1/thy.2015.0551.pd

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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