Microwave-Induced Combustion Synthesis of Luminescent Aluminate Powders

ISBN 978-953-51-0371-4 Chapitre

Tuning the domain wall orientation in thin magnetic strips by induced anisotropy

We report on a method to tune the orientation of in-plane magnetic domains and domain walls in thin ferromagnetic strips by manipulating the magnetic anisotropy. Uniaxial in-plane anisotropy is induced in a controlled way by oblique evaporation of magnetic thin strips. A direct correlation between the magnetization direction and the domain wall orientation is found experimentally and confirmed by micromagnetic simulations. The domain walls in the strips are always oriented along the oblique evaporation-induced easy axis, in spite of the shape anisotropy. The controlled manipulation of domain wall orientations could open new possibilities for novel devices based on domain-wall propagation

Evaluating the taxa that provide shared pollination services across multiple crops and regions

Many pollinator species visit multiple crops in multiple regions, yet we know little about their pollination service provisioning at local and regional scales. We investigated the floral visitors (n = 13,200), their effectiveness (n = 1718 single visits) and response to landscape composition across three crops avocado, mango and macadamia within a single growing region (1 year), a single crop (3 years) and across different growing regions in multiple years. In total, eight wild visitor groups were shared across all three crops. The network was dominated by three pollinators, two bees (Apis mellifera and Tetragonula spp.) and a fly, Stomorhina discolor. The visitation network for the three crops was relatively generalised but with the addition of pollen deposition data, specialisation increased. Sixteen managed and wild taxa were consistently present across three years in avocado, yet their contribution to annual network structure varied. Node specialisation (d’) analyses indicated many individual orchard sites across each of the networks were significantly more specialised compared to that predicted by null models, suggesting the presence of site-specific factors driving these patterns. Identifying the taxa shared across multiple crops, regions and years will facilitate the development of specific pollinator management strategies to optimize crop pollination services in horticultural systems

Reconstructive complications and early toxicity in breast cancer patients treated with proton-based postmastectomy radiation therapy

BackgroundPostmastectomy radiation therapy (PMRT) decreases the risk of locoregional recurrence and increases overall survival rates in patients with high-risk node positive breast cancer. While the number of breast cancer patients treated with proton-based PMRT has increased in recent years, there is limited data on the use of proton therapy in the postmastectomy with reconstruction setting. In this study, we compared acute toxicities and reconstructive complications in patients treated with proton-based and photon-based PMRT.MethodsA retrospective review of our institutional database was performed to identify breast cancer patients treated with mastectomy with implant or autologous reconstruction followed by PMRT from 2015 to 2020. Baseline clinical, disease, and treatment related factors were compared between the photon-based and proton-based PMRT groups. Early toxicity outcomes and reconstructive complications following PMRT were graded by the treating physician.ResultsA total of 11 patients treated with proton-based PMRT and 26 patients treated with photon-based PMRT were included with a median follow-up of 7.4 months (range, 0.7-33 months). Six patients (55%) in the proton group had a history of breast cancer (3 ipsilateral and 3 contralateral) and received previous RT 38 months ago (median, range 7-85). There was no significant difference in mean PMRT (p = 0.064) and boost dose (p = 0.608) between the two groups. Grade 2 skin toxicity was the most common acute toxicity in both groups (55% and 73% in the proton and photon group, respectively) (p = 0.077). Three patients (27%) in the proton group developed grade 3 skin toxicity. No Grade 4 acute toxicity was reported in either group. Reconstructive complications occurred in 4 patients (36%) in the proton group and 8 patients (31%) in photon group (p = 0.946).ConclusionsAcute skin toxicity remains the most frequent adverse event in both proton- and photon-based PMRT. In our study, reconstructive complications were not significantly higher in patients treated with proton- versus photon-based PMRT. Longer follow-up is warranted to assess late toxicities

Nanocrystalline lanthanide-doped Lu3Ga5O12 garnets: interesting materials for light-emitting devices

Nanocrystalline Lu3Ga5O12, with average particle sizes of 40 nm, doped with a wide variety of luminescent trivalent lanthanide ions have been prepared using a sol\u2013gel technique. The structural and morphological properties of the powders have been investigated by x-ray powder diffraction, high resolution transmission electron microscopy and Raman spectroscopy. Structural data have been refined and are presented for Pr3+, Eu3+, Gd3+, Ho3+, Er3+ and Tm3+ dopants, while room temperature excited luminescence spectra and emission decay curves of Eu3+-, Tm3+- and Ho3+-doped Lu3Ga5O12 nanocrystals have been measured and are discussed. The Eu3+ emission spectrum shows typical bands due to 5D0 \u21927FJ (J = 0, 1, 2, 3, 4) transitions and the broadening of these emission bands with the non-exponential behaviour of the decay curves indicates the presence of structural disorder around the lanthanide ions. Lanthanide-doped nanocrystalline Lu3Ga5O12 materials show better luminescence intensities compared to Y2O3, Gd3Ga5O12 and Y3Al5O12 nanocrystalline hosts. Moreover, the upconversion emission intensity in the blue-green region for the Tm3+- and Ho3+-doped samples shows a significant increase upon 647.5 nm excitation with respect to other common oxide hosts doped with the same lanthanide ions

Nanophosphors, a catalyst for micro-LED technology development.

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Quantitative wave-optical numerical analysis of the dark-field signal in grating-based X-ray interferometry

Here we report a full wave-optical numerical simulation framework that quantitatively predicts the outcome of grating-based X-ray dark-field imaging experiments on an ensemble of sub-pixel spherical scatterers. We particularly show how the behavior of the dark-field imaging signal differs from and complements the conventional X-ray transmission imaging signal when certain sample parameters, such as the size, number, and total volume of sub-pixel spherical substructures are changed and compare our findings to previous experiments and theoretical work. We believe that this work represents an important step in further understanding and applying the dark-field signal for future advanced X-ray imaging applications in medicine, materials science, and non-destructive industrial testing