170,058 research outputs found
Magneto-optical measurements in thin film of frequency dependence of hysteresis loops from 10 mHz to 10 kHz
No full textThe Last Supper information system: samples from Gallone archive
No full textMapping at the service of conservation: designing an information system to reference the samples on the artwork surface. Towards an open access online repository of the analytical data about the work of Leonardo da Vinci, sharing knowledge among scholars involved in the conservation field
Bulk and surface magnetic study of Fe80B20 crystallization
No full textWe report a study relating the evolution of coercivity H-c, both in the bulk and in the surface region, to the microstructural changes occurring during the first stage of the crystallization process of Fe80B20 amorphous samples. The coercive field H-c has been studied with a magneto-optical Kerr ellipsometer in the surface and with a vibrating sample magnetometer in the bulk. The observed behavior of H-c can be accounted for by considering its dependence on the number density of grains and gives information on the domain wall dynamic indicating the occurrence of a two dimensional bending of the domain walls. In addition, the evolution of H-c is substantially insensitive to the details of the internal structure of the grains. This study reveals that the surface crystallization occurs via the same processes as in the bulk but it takes place at lower temperature with respect to the bulk. We also measured the Curie temperature of the surface region of the amorphous ribbon and we obtained a lower value with respect to the bulk. (C) 1997 American Institute of Physics
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Evolution of coercivity during the early stages of Fe80B20 crystallization
No full textWe report a study of the evolution of coercivity (H-c) in partially crystallized Fe80B20 samples with an increasing number of crystallites obtained in a controlled way into ferromagnetic amorphous matrix. These samples allow to test existing models for interaction of domain walls with defects since it is possible to change only the number density of crystallites without modifying their dimensions. We observe that the evolution of H-c is mainly related to the nucleation frequency of grains and quite independent from their internal structure. The observed behavior of H-c can be accounted for by considering the dependence of coercivity on the number density of pinning sites and by assuming a two-dimensional bending of the domain walls during their motion. Moreover our results indicate that the changes occurring to the intergranular phase during annealing do not appreciably affect coercivity in the partially crystallized samples
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
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