180 research outputs found
Magnetoplasmonic design rules for active magneto-optics
Light polarization rotators and non-reciprocal optical isolators are
essential building blocks in photonics technology. These macroscopic passive
devices are commonly based on magneto-optical Faraday and Kerr polarization
rotation. Magnetoplasmonics - the combination of magnetism and plasmonics - is
a promising route to bring these devices to the nanoscale. We introduce design
rules for highly tunable active magnetoplasmonic elements in which we can
tailor the amplitude and sign of the Kerr response over a broad spectral range
magnetic and structural investigation of growth induced magnetic anisotropies in fe50co50 thin films
In this paper, we investigate the magnetic properties of Fe50 Co50 polycrystalline thin films, grown by dc-magnetron sputtering, with thickness (t) ranging from 2.5 nm up to 100 nm. We focused on the magnetic properties of the samples to highlight the effects of possible intrinsic stress that may develop during growth, and their dependence on film thickness. Indeed, during film deposition, due to the growth technique and growth conditions, a metallic film may display an intrinsic compressive or tensile stress. In our case, due to the Fe50Co50 magnetolastic properties, this stress may in its turn promote the development of magnetic anisotropies. Samples magnetic properties were monitored with a SQUID magnetometer and a magnetoâoptic Kerr effect apparatus, using both an inâplane and an outâofâplane magnetic field. Magnetoresistance measurements were collected, as well, to further investigate the magnetic behavior of the samples. Indications about the presence of intrinsic stress were obtained accessing samples curvature with an optical profilometer. For t †20 nm, the shape of the in-plane magnetization loops is squared and coercivity increases with t, possibly due to fact that, for small t values, the grain size grows with t. The magnetoresistive response is anisotropic in character. For t > 20 nm, coercivity smoothly decreases, the approach to saturation gets slower and the shape of the whole loop gets less and less squared. The magnetoresistive effect becomes almost isotropic and its intensity increases of about one order of magnitude. These results suggest that the magnetization reorientation process changes for t > 20 nm, and are in agreement with the progressive development of an out-of-plane easy axis. This hypothesis is substantiated by profilometric analysis that reveals the presence of an in-plane compressive stress
Pr 0.5 Ca 0.5 MnO 3 thin films deposited on LiNbO 3 substrates
Thin films of Pr 0.5 Ca 0.5 MnO 3 have been deposited on z-cut LiNbO 3 by pulsed laser ablation. The X-ray diffraction measurements showed that the films have grown highly oriented on LiNbO 3 , with a pseudocubic (111) preferred growth direction. The thicknesses of the films, measured by low angle X-ray reflectivity, are between 13 and 140 nm. Their electrical resistivity present a semiconducting-like behaviour with an anomaly around 240 K, that corresponds to the charge ordering transition. The temperature of the transition (T_CO) was estimated from ln(r) vs. (1/T) plots. The charge ordering temperature was found to be dependent on the strain induced by the lattice mismatch on the films.Fundação para a CiĂȘncia e a Tecnologia (FCT
High-dose-rate Brachytherapy as Adjuvant Local rEirradiation for Salvage Treatment of Recurrent breAst cancer (BALESTRA): a retrospective mono-institutional study
Purpose: To evaluate clinical results of catheter-based interstitial high-dose-rate (HDR) brachytherapy (BT) as adjuvant treatment in previously irradiated recurrent breast cancer.
Material and methods: Between January 2011 and September 2015, 31 consecutive patients with histologically confirmed recurrent breast cancer after conservative surgery and conventional whole breast radiotherapy, were retreated with a second conservative surgical resection and reirradiated with adjuvant interstitial HDR-BT. None of the brachytherapy implant was performed during the quadrantectomy procedure. A dose of 34 Gy in 10 fractions, 2 fractions per day, with a minimal interval of 6 hours was delivered.
Results: At the time of the implant, the median age of patients was 59.7 years (range, 39.3-74.9 years). The median time from first treatment until BT for local recurrence was 11.9 years (range, 2.5-27.8 years). The median interval between salvage surgery and BT was 3.6 months (range, 1-8.2 months). No acute epidermitis or soft tissue side effects higher than grade 2 were recorded, with good cosmetic results in all patients. Most of the patients presented grade 1-2 late side effects. Only one patient developed grade 3 liponecrosis. After a median follow-up of 73.7 months (range, 28.8-102.4 months), the overall survival and cancer specific survival were 87.1% and 90.3%, respectively; 5-year local control and 5-year progression-free survival rate were 90.3% and 83.9%, respectively.
Conclusions: Our preliminary analysis showed that HDR-BT is a feasible treatment for partial breast reirradiation offering very low complications rate and fast procedure. Higher patients' cohort is warranted in order to define the role of this treatment modality in the breast conservative management of local recurrence
Integrated quantitative PIXE analysis and EDX spectroscopy using a laser-driven particle source
Among the existing elemental characterization techniques, Particle Induced
X-ray Emission (PIXE) and Energy Dispersive X-ray (EDX) spectroscopy are two of
the most widely used in different scientific and technological fields. Here we
present the first quantitative laser-driven PIXE and laser-driven EDX
experimental investigation performed at the Centro de L\'aseres Pulsados in
Salamanca. Thanks to their potential for compactness and portability,
laser-driven particle sources are very appealing for materials science
applications, especially for materials analysis techniques. We demonstrate the
possibility to exploit the X-ray signal produced by the co-irradiation with
both electrons and protons to identify the elements in the sample. We show
that, using the proton beam only, we can successfully obtain quantitative
information about the sample structure through laser-driven PIXE analysis.
These results pave the way towards the development of a compact and
multi-functional apparatus for the elemental analysis of materials based on a
laser-driven particle source.Comment: This project has received funding from the European Research Council
(ERC) under the European Union's Horizon 2020 research and innovation
programme (ENSURE grant agreement No. 647554). Submitted to Science Advances
on 20th May 2
Adjuvant vaginal interventional radiotherapy in early-stage non-endometrioid carcinoma of corpus uteri: a systematic review
Purpose: This systematic review focused on rare histological types of corpus uteri malignancy, including uterine carcinosarcoma (UCS), uterine clear cell carcinoma (UCCC), and uterine papillary serous carcinoma (UPSC), and it is proposed to assist with clinical decision-making. Adjuvant treatment decisions must be made based on available evidences. We mainly investigated the role of vaginal interventional radiotherapy (VIRt) in UCS, UCCC, and UPSC managements.
Material and methods: A systematic research using PubMed and Cochrane library was conducted to identify full articles evaluating the efficacy of VIRt in early-stage UPSC, UCCC, and UCS. A search in ClinicalTrials.gov was performed in order to detect ongoing or recently completed trials as well as in PROSPERO for ongoing or recently completed systematic reviews. Survival outcomes and toxicity rates were obtained.
Results: All studies were retrospective. For UCS, the number of evaluated patients was 432. The 2- to 5-year aver- age local control (LC) was 91% (range, 74.2-96%), disease-free survival (DFS) 88% (range, 82-94%), overall survival (OS) 79% (range, 53.8-84.3%), the average 5-year cancer-specific survival (CSS) was 70% (range, 70-94%), and G3-G4 toxicity was 0%. For UCCC, the number of investigated patients was 335 (UCCC â 124, mixed â 211), with an average 5-year LC of 100%, DFS of 83% (range, 82-90%), OS of 93% (range, 83-100%), and G3-G4 toxicity of 0%. For UPSC, the number of examined patients was 1,092 (UPSC â 866, mixed â 226). The average 5-year LC was 97% (range, 87.1-100%), DFS 84% (range, 74.7-95.6%), OS 93% (range, 71.9-100%), CSS 89% (range, 78.9-94%), and G3-G4 toxicity was 0%.
Conclusions: These data suggest that in adequately selected early-stage UPSC and UCCC patients, VIRt alone may be suitable in women who underwent surgical staging and received adjuvant chemotherapy. In early-stage UCS, a multidisciplinary therapeutic approach has to be planned, considering high-rate of pelvic and distant relapses
Directionâsensitive magnetophotonic surface crystals
Nanometer-thin rare-earthâtransition-metal (REâTM) alloys with precisely controlled compositions and out-of-plane magnetic anisotropy are currently in the focus for ultrafast magnetophotonic applications. However, achieving lateral nanoscale dimensions, crucial for potential device downscaling, while maintaining designable optomagnetic functionality and out-of-plane magnetic anisotropy is extremely challenging. Herein, nanosized Tb18Co82 ferrimagnetic alloys, having strong out-of-plane magnetic anisotropy, within a gold plasmonic nanoantenna array to design a micrometer-scale magnetophotonic crystal that exhibits abrupt and narrow magneto-optical (MO) spectral features that are both magnetic field and light incidence direction controlled are integrated. The narrow Fano-type resonance arises through the interference of the individual nanoantenna's surface plasmons and a Rayleigh anomaly of the whole nanoantenna array, in both optical and MO spectra, which are demonstrated and explained using Maxwell theory simulations. This robust magnetophotonic crystal opens the way for conceptually new high-resolution light incidence direction sensors, as well as for building blocks for plasmon-assisted all-optical magnetization switching in ferrimagnetic REâTM alloys
Designer Magnetoplasmonics with Nickel Nanoferromagnets
We introduce a new perspective on magnetoplasmonics in nickel nanoferromagnets by exploiting the phase tunability of the optical polarizability due to localized surface plasmons and simultaneous magneto-optical activity. We demonstrate how the concerted action of nanoplasmonics and magnetization can manipulate the sign of rotation of the reflected lightâs polarization (i.e., to produce Kerr rotation reversal) in ferromagnetic nanomaterials and, further, how this effect can be dynamically controlled and employed to devise conceptually new schemes for biochemosensing. © 2011 American Chemical Society.A.D. and Z.P. acknowledge support from the Swedish Research Council and Swedish Foundation for Strategic Research (Framework program Functional Electromagnetic Metamaterials,
project RMA08). J.Ă
. acknowledges support from the Swedish Research Council, the Swedish Foundation for Strategic Research (Future Research Leader Programme), and the GâŹoran Gustafsson Foundation. J.Ă
. is a Royal Swedish Academy of Sciences Research Fellow supported by a grant from the Knut and Alice Wallenberg Foundation. V.B. acknowledges the GâŹoran Gustafsson Foundation and the Blanceflor Boncompagni-Ludovisi Foundation. P.V. acknowledges funding from the Basque Government
through the ETORGAI Program, Project No. ER-
2010/00032 and Program No. PI2009-17, the Spanish Ministry of Science and Education under Projects No. CSD2006-53 and No. MAT2009-07980. J.N. acknowledges funding for the Generalitat de Catalunya and the Spanish Ministry of Science and
Education through No. 2009-SGR-1292 and No. MAT2010-20616-C02 projects.Peer Reviewe
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