3 research outputs found

    UV integrated optics devices based on beta-barium borate

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    We report on our recent progress in development of ultraviolet (UV) integrated optics devices based on beta-barium borate (BBO). Planar optical waveguides with a thickness of a few micrometers have been formed by the implantation of He+ ions with energies of around 2 MeV. Two alternative methods based on the femtosecond-laser assisted micromachining and lithographic structuring for the fabrication of ridge-type channel optical waveguides in implanted BBO crystals have been developed, and the transmission properties of the obtained waveguides have been studied. We demonstrate a big potential of the fabricated channel waveguides for the second harmonic generation of continuous-wave deep-UV laser light with a power of the order of 1 mW, exploiting the nonlinear optical properties of BBO crystal. In addition, a low-voltage electro-optic waveguide modulator for the deep-UV light (half-wave voltage times electrode length V蟺 脳 l = 43 V cm at 257 nm) was realized for the first time

    Comparing accuracy of tomosynthesis plus digital mammography or synthetic 2D mammography in breast cancer screening: baseline results of the MAITA RCT consortium

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    Aim: The analyses here reported aim to compare the screening performance of digital tomosynthesis (DBT) versus mammography (DM). Methods: MAITA is a consortium of four Italian trials, REtomo, Proteus, Impeto, and MAITA trial. The trials adopted a two-arm randomised design comparing DBT plus DM (REtomo and Proteus) or synthetic-2D (Impeto and MAITA trial) versus DM; multiple vendors were included. Women aged 45 to 69 years were individually randomised to one round of DBT or DM. Findings: From March 2014 to February 2022, 50,856 and 63,295 women were randomised to the DBT and DM arm, respectively. In the DBT arm, 6656 women were screened with DBT plus synthetic-2D. Recall was higher in the DBT arm (5路84% versus 4路96%), with differences between centres. With DBT, 0路8/1000 (95% CI 0路3 to 1路3) more women received surgical treatment for a benign lesion. The detection rate was 51% higher with DBT, ie. 2路6/1000 (95% CI 1路7 to 3路6) more cancers detected, with a similar relative increase for invasive cancers and ductal carcinoma in situ. The results were similar below and over the age of 50, at first and subsequent rounds, and with DBT plus DM and DBT plus synthetic-2D. No learning curve was appreciable. Detection of cancers >= 20 mm, with 2 or more positive lymph nodes, grade III, HER2-positive, or triple-negative was similar in the two arms. Interpretation: Results from MAITA confirm that DBT is superior to DM for the detection of cancers, with a possible increase in recall rate. DBT performance in screening should be assessed locally while waiting for long-term follow-up results on the impact of advanced cancer incidence
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