215 research outputs found

    Surgical Treatment with Locoregional Flap for the Nose

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    Nonmelanotic skin cancers (NMSCs) are the most frequent of all neoplasms and nasal pyramid represents the most common site for the presentation of such cutaneous malignancies, particularly in sun-exposed areas: ala, dorsum, and tip. Multiple options exist to restore functional and aesthetic integrity after skin loss for oncological reasons; nevertheless, the management of nasal defects can be often challenging and the best "reconstruction" is still to be found. In this study, we retrospectively reviewed a total of 310 patients who presented to our Department of Plastic and Reconstructive Surgery for postoncological nasal reconstruction between January 2011 and January 2016. Nasal region was classified into 3 groups according to the anatomical zones affected by the lesion: proximal, middle, and distal third. We included an additional fourth group for complex defects involving more than one subunit. Reconstruction with loco regional flaps was performed in all cases. Radical tumor control and a satisfactory aesthetic and functional result are the primary goals for the reconstructive surgeon. Despite tremendous technical enhancements in nasal reconstruction techniques, optimal results are usually obtained when "like is used to repair like." Accurate evaluation of the patients clinical condition and local defect should be always considered in order to select the best surgical option

    Phase I trial of the combination of the Akt inhibitor nelfinavir and chemoradiation for locally advanced rectal cancer

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    PURPOSE: To investigate the toxicity of nelfinavir, administered during preoperative chemoradiotherapy (CRT) in patients with locally advanced cancer. MATERIAL AND METHODS: Twelve patients were treated with to 50.4Gy combined with capecitabine 825mg/m2 BID. Three dose levels nelfinavir were tested: 750mg BID (DL1), 1250mg BID (DL2) and an level of 1000mg BID (DL3). Surgery was performed between 8 and 10weeks completion of CRT. Primary endpoint was dose-limiting toxicity (DLT), any grade 3 or higher non-hematological or grade 4 or higher toxicity. RESULTS: Eleven patients could be analyzed: 5 were treated in DL2 and 3 in DL3. The first 3 patients in DL1 did not develop a DLT. In patient developed gr 3 diarrhea, 1 patient had gr 3 transaminase patient had a gr 3 cholangitis with unknown cause. An intermediate dose tested in DL3. In this group 2 patients developed gr 3 diarrhea and 1 3 transaminase elevation and gr 4 post-operative wound complication. patients achieved a pathological complete response (pCR). CONCLUSIONS: 750mg BID was defined as the recommended phase II dose in combination capecitabine and 50.4Gy pre-operative radiotherapy in rectal cancer. response evaluations are promising, but a further phase II study is more information about efficacy of this treatment regimen

    Elliptical Squeezed States and Rydberg Wave Packets

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    We present a theoretical construction for closest-to-classical wave packets localized in both angular and radial coordinates and moving on a keplerian orbit. The method produces a family of elliptical squeezed states for the planar Coulomb problem that minimize appropriate uncertainty relations in radial and angular coordinates. The time evolution of these states is studied for orbits with different semimajor axes and eccentricities. The elliptical squeezed states may be useful for a description of the motion of Rydberg wave packets excited by short-pulsed lasers in the presence of external fields, which experiments are attempting to produce. We outline an extension of the method to include certain effects of quantum defects appearing in the alkali-metal atoms used in experiments.Comment: published in Phys. Rev. A, vol. 52, p. 2234, Sept. 199

    Analytic results for Gaussian wave packets in four model systems: II. Autocorrelation functions

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    The autocorrelation function, A(t), measures the overlap (in Hilbert space) of a time-dependent quantum mechanical wave function, psi(x,t), with its initial value, psi(x,0). It finds extensive use in the theoretical analysis and experimental measurement of such phenomena as quantum wave packet revivals. We evaluate explicit expressions for the autocorrelation function for time-dependent Gaussian solutions of the Schrodinger equation corresponding to the cases of a free particle, a particle undergoing uniform acceleration, a particle in a harmonic oscillator potential, and a system corresponding to an unstable equilibrium (the so-called `inverted' oscillator.) We emphasize the importance of momentum-space methods where such calculations are often more straightforwardly realized, as well as stressing their role in providing complementary information to results obtained using position-space wavefunctions.Comment: 18 pages, RevTeX, to appear in Found. Phys. Lett, Vol. 17, Dec. 200

    Keplerian Squeezed States and Rydberg Wave Packets

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    We construct minimum-uncertainty solutions of the three-dimensional Schr\"odinger equation with a Coulomb potential. These wave packets are localized in radial and angular coordinates and are squeezed states in three dimensions. They move on elliptical keplerian trajectories and are appropriate for the description of the corresponding Rydberg wave packets, the production of which is the focus of current experimental effort. We extend our analysis to incorporate the effects of quantum defects in alkali-metal atoms, which are used in experiments.Comment: accepted for publication in Physical Review

    Prevention of Neural Tube Defects: A Cross-Sectional Study of the Uptake of Folic Acid Supplementation in Nearly Half a Million Women

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    BACKGROUND: Taking folic acid supplements before pregnancy to reduce the risk of a neural tube defect (NTD) is especially important in countries without universal folic acid fortification. The extent of folic acid supplementation among women who had antenatal screening for Down's syndrome and NTDs at the Wolfson Institute of Preventive Medicine, London between 1999 and 2012 was assessed. METHODS AND FINDINGS: 466,860 women screened provided details on folic acid supplementation. The proportion of women who took folic acid supplements before pregnancy was determined according to year and characteristics of the women. The proportion of women taking folic acid supplements before pregnancy declined from 35% (95% CI 34%-35%) in 1999-2001 to 31% (30%-31%) in 2011-2012. 6% (5%-6%) of women aged under 20 took folic acid supplements before pregnancy compared with 40% of women aged between 35 and 39. Non-Caucasian women were less likely to take folic acid supplements before pregnancy than Caucasian women; Afro-Caribbean 17% (16%-17%), Oriental 25% (24%-25%) and South Asian 20% (20%-21%) compared with 35% (35%-35%) for Caucasian women. 51% (48%-55%) of women who previously had an NTD pregnancy took folic acid supplements before the current pregnancy. CONCLUSIONS: The policy of folic acid supplementation is failing and has led to health inequalities. This study demonstrates the need to fortify flour and other cereal grain with folic acid in all countries of the world

    Long-Term Evolution and Revival Structure of Rydberg Wave Packets for Hydrogen and Alkali-Metal Atoms

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    This paper begins with an examination of the revival structure and long-term evolution of Rydberg wave packets for hydrogen. We show that after the initial cycle of collapse and fractional/full revivals, which occurs on the time scale trevt_{\rm rev}, a new sequence of revivals begins. We find that the structure of the new revivals is different from that of the fractional revivals. The new revivals are characterized by periodicities in the motion of the wave packet with periods that are fractions of the revival time scale trevt_{\rm rev}. These long-term periodicities result in the autocorrelation function at times greater than trevt_{\rm rev} having a self-similar resemblance to its structure for times less than trevt_{\rm rev}. The new sequence of revivals culminates with the formation of a single wave packet that more closely resembles the initial wave packet than does the full revival at time trevt_{\rm rev}, i.e., a superrevival forms. Explicit examples of the superrevival structure for both circular and radial wave packets are given. We then study wave packets in alkali-metal atoms, which are typically used in experiments. The behavior of these packets is affected by the presence of quantum defects that modify the hydrogenic revival time scales and periodicities. Their behavior can be treated analytically using supersymmetry-based quantum-defect theory. We illustrate our results for alkali-metal atoms with explicit examples of the revival structure for radial wave packets in rubidium.Comment: To appear in Physical Review A, vol. 51, June 199

    Edge-Magnetoplasmon Wave-Packet Revivals in the Quantum Hall Effect

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    The quantum Hall effect is necessarily accompanied by low-energy excitations localized at the edge of a two-dimensional electron system. For the case of electrons interacting via the long-range Coulomb interaction, these excitations are edge magnetoplasmons. We address the time evolution of localized edge-magnetoplasmon wave packets. On short times the wave packets move along the edge with classical E cross B drift. We show that on longer times the wave packets can have properties similar to those of the Rydberg wave packets that are produced in atoms using short-pulsed lasers. In particular, we show that edge-magnetoplasmon wave packets can exhibit periodic revivals in which a dispersed wave packet reassembles into a localized one. We propose the study of edge-magnetoplasmon wave packets as a tool to investigate dynamical properties of integer and fractional quantum-Hall edges. Various scenarios are discussed for preparing the initial wave packet and for detecting it at a later time. We comment on the importance of magnetoplasmon-phonon coupling and on quantum and thermal fluctuations.Comment: 18 pages, RevTex, 7 figures and 2 tables included, Fig. 5 was originally 3Mbyte and had to be bitmapped for submission to archive; in the process it acquired distracting artifacts, to upload the better version, see http://physics.indiana.edu/~uli/publ/projects.htm

    Uplifting manhood to wonderful heights? News coverage of the human costs of military conflict from world war I to Gulf war Two

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    Domestic political support is an important factor constraining the use of American military power around the world. Although the dynamics of war support are thought to reflect a cost-benefit calculus, with costs represented by numbers of friendly war deaths, no previous study has examined how information about friendly, enemy, and civilian casualties is routinely presented to domestic audiences. This paper establishes a baseline measure of historical casualty reporting by examining New York Times coverage of five major wars that occurred over the past century. Despite important between-war differences in the scale of casualties, the use of conscription, the type of warfare, and the use of censorship, the frequency of casualty reporting and the framing of casualty reports has remained fairly consistent over the past 100 years. Casualties are rarely mentioned in American war coverage. When casualties are reported, it is often in ways that minimize or downplay the human costs of war
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