0000000000135061
AUTHOR
Andrea Toma
showing 7 related works from this author
Molecular predictors of response to decitabine in advanced chronic myelomonocytic leukemia: a phase 2 trial.
2011
Abstract Hydroxyurea is the standard therapy of chronic myelomonocytic leukemia (CMML) presenting with advanced myeloproliferative and/or myelodysplastic features. Response to hypomethylating agents has been reported in heterogeneous series of CMML. We conducted a phase 2 trial of decitabine (DAC) in 39 patients with advanced CMML defined according to a previous trial. Median number of DAC cycles was 10 (range, 1-24). Overall response rate was 38% with 4 complete responses (10%), 8 marrow responses (21%), and 3 stable diseases with hematologic improvement (8%). Eighteen patients (46%) demonstrated stable disease without hematologic improvement, and 6 (15%) progressed to acute leukemia. With…
Outcome of lower-risk patients with myelodysplastic syndromes without 5q deletion after failure of erythropoiesis-stimulating agents
2017
Purpose Most anemic patients with non-deleted 5q lower-risk myelodysplastic syndromes (MDS) are treated with erythropoiesis-stimulating agents (ESAs), with a response rate of approximately 50%. Second-line treatments, including hypomethylating agents (HMAs), lenalidomide (LEN), and investigational drugs, may be used after ESA failure in some countries, but their effect on disease progression and overall survival (OS) is unknown. Here, we analyzed outcome after ESA failure and the effect of second-line treatments. Patients and Methods We examined an international retrospective cohort of 1,698 patients with non-del(5q) lower-risk MDS treated with ESAs. Results Erythroid response to ESAs was 6…
Highly Sensitive Polarization Rotation Measurement through a High‐Order Vector Beam Generated by a Metasurface
2020
The precise determination of the polarization state of light is fundamental for a vast variety of applications in remote sensing, astronomy, optics and terahertz technology, to name just a few. Typically, polarization characterization is performed by using a combination of multiple optical devices such as beam splitters, polarizers, and waveplates. Moreover, to achieve high-precision, balanced photodetectors and lock-in amplifiers are employed, thus contributing to increasing system complexity. Here, a technique for polarization rotation measurements with a dynamic range of 180° and a sensitivity of about 10−2 degrees is realized using a properly designed metasurface. Such device generates …
Antenna Tapering Strategy for Near-Field Enhancement Optimization in Terahertz Gold Nanocavities
2019
Plasmonic nanoantennas (NAs) have received a growing attention in recent years due to their ability to confine light on sub-wavelength dimensions [1]. More recently, this property has been exploited in the terahertz (THz) frequency range (0.1–10 THz) for enhanced sensing and spectroscopy [2], as well as for more fundamental investigations [3]. These applications typically require high local electric fields that can be achieved by concentrating THz radiation into deeply sub-wavelength volumes located at the NAs extremities. However, the achievable near-field enhancement values are severely limited by the poor resonance quality factor of traditional rod-shaped THz NAs. Unlike what is commonly…
Rotational Doppler Frequency Shift from Time‐Evolving High‐Order Pancharatnam–Berry Phase: A Metasurface Approach
2021
The Doppler frequency shift of sound or electromagnetic waves has been widely investigated in many different contexts and, nowadays, represents a formidable tool in medicine, engineering, astrophysics, and optics. Such effect is commonly described in the framework of the universal energy-momentum conservation law. In particular, the rotational Doppler effect has been recently demonstrated using light carrying orbital angular momentum. When a wave undergoes a cyclic adiabatic transformation of its Hamiltonian, it is known to acquire the so-called Pancharatnam–Berry (PB) phase. In this work, an experimental evidence of the direct connection between the high-order PB phase time evolution on th…
Generation of Structured Light via Nano Structures and Applications
2020
The generation of structured light by means of metasurfaces is presented and the applications in the characterizations of polarization rotation and Pancharatnam-Berry phase are discussed.
Improving nanoscale terahertz field localization by means of sharply tapered resonant nanoantennas
2020
Abstract Terahertz resonant nanoantennas have recently become a key tool to investigate otherwise inaccessible interactions of such long-wavelength radiation with nano-matter. Because of their high-aspect-ratio rod-shaped geometry, resonant nanoantennas suffer from severe loss, which ultimately limits their field localization performance. Here we show, via a quasi-analytical model, numerical simulations, and experimental evidence, that a proper tapering of such nanostructures relaxes their overall loss, leading to an augmented local field enhancement and a significantly reduced resonator mode volume. Our findings, which can also be extended to more complex geometries and higher frequencies,…