187,141 research outputs found
Molecular structure of highly excited resonant states in Mg-24 and the corresponding Be-8+O-16 and C-12+C-12 decays
No full textExotic Be-8 and C-12 decays from high-lying resonances in Mg-24 are analyzed in terms of a cluster model. The calculated quantities agree well with the corresponding experimental data. It is found that the calculated decay widths are very sensitive to the angular momentum carried by the outgoing cluster. It is shown that this property makes cluster decay a powerful tool to determine the spin as well as the molecular structures of the resonances.Physics, NuclearSCI(E)7ARTICLE5null8
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
B -> eta K-c(eta ' K-c) decays in QCD factorization
No full textWe study the exclusive decays of the B meson into pseudoscalar charmonium states eta(c) and eta(c)' within the QCD factorization approach and find that the non-factorizable corrections to naive factorization are infrared safe at leading-twist order. The spectator interactions arising from the kaon twist-3 effects are formally power suppressed but chirally and logarithmically enhanced. An important improvement by including the O(alpha(s)) corrections is the cancellation of the renormalization scale mu dependence of the decay amplitude. However, the calculated decay rates are too small to accommodate the experimental data. On the other hand, we compare the theoretical calculations for B meson decays to J/psi, psi', eta(c) and eta'(c), and find that the predicted relative decay rates of these four states are approximately compatible with the experimental data.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000223097800007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, Particles & FieldsSCI(E)17ARTICLE3365-3703
History sketch 157th Engineer (C) Bn.
No full textThis is a historical description of the 157th Engineer (C) Battalion written from memory by author. Notes are not attached as described on last page of document
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
Full text linkThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Microscopic mechanism of charged-particle radioactivity and generalization of the Geiger-Nuttall law
No full textA linear relation for charged-particle emissions is presented starting from the microscopic mechanism of the radioactive decay. It relates the logarithms of the decay half-lives with two variables, called. chi' and. rho', which depend upon the Q values of the outgoing clusters as well as the masses and charges of the nuclei involved in the decay. This relation explains well all known cluster decays. It is found to be a generalization of the Geiger-Nuttall law in a radioactivity, and therefore we call it the universal decay law. Predictions of the most likely emissions of various clusters are presented by applying the law over the whole nuclear chart. It is seen that the decays of heavier clusters with nonequal proton and neutron numbers are mostly located in the trans-lead region. The emissions of clusters with equal protons and neutrons, like (12)C and (16)O, are possible in some neutron-deficient nuclei with Z >= 54.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000271352900039&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, NuclearSCI(E)51ARTICLE4null8
Awareness, Type of Medium, and L2 Development: Revisiting Hsieh (2008)
No full textThe small number of published studies that has empirically compared face-to-face (FTF) instruction against computer-assisted instruction (CAI) appears to support superior learning benefits for CAI (cf. AbuSeileek, 2009; AbuSeileek & Rababah, 2007; Nutta, 1998; Torlaković & Deugo 2004; cf. Hsieh, 2008 for no effects). However, a recent critical review of these studies’ internal validity (Cerezo, Baralt, Suh, & Leow, 2013) reveals that the relative effects of this computerized medium against FTF instruction are still unclear and calls for a closer investigation of the cognitive processes employed while interacting with L2 data across type of medium. Interestingly, Hsieh (2008) collected but did not report concurrent data produced by her participants during L2 data exposure to a computerized version of the FTF instruction (C-FTF) and CAI conditions in her published study. This chapter seeks to address this important call by revisiting Hsieh (2008) to qualitatively compare, from a psycholinguistic perspective, the cognitive processes, and more specifically, level of awareness, employed in each type of medium (C-FTF vs. CAI) regarding the L2 development of a morpho-syntactic structure such as gustar ‘to please’ at the beginning level of Spanish. The findings indicate that the features of each instructional medium clearly prompted different levels of awareness and depth of processing. These findings also provide plausible explanations for the non-significant differences in performances between the two groups and for the superior gain scores on a delayed posttest for the CAI group reported in the original study and other studies. A pedagogical implication is provided
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