Laser induced fluorescence for axion dark matter detection: a feasibility study in YLiF4_4:Er3+^{3+}

We present a detection scheme to search for QCD axion dark matter, that is based on a direct interaction between axions and electrons explicitly predicted by DFSZ axion models. The local axion dark matter field shall drive transitions between Zeeman-split atomic levels separated by the axion rest mass energy $m_a c^2$. Axion-related excitations are then detected with an upconversion scheme involving a pump laser that converts the absorbed axion energy ($\sim$ hundreds of $\mu$eV) to visible or infrared photons, where single photon detection is an established technique. The proposed scheme involves rare-earth ions doped into solid-state crystalline materials, and the optical transitions take place between energy levels of $4f^N$ electron configuration. Beyond discussing theoretical aspects and requirements to achieve a cosmologically relevant sensitivity, especially in terms of spectroscopic material properties, we experimentally investigate backgrounds due to the pump laser at temperatures in the range $1.9-4.2$ K. Our results rule out excitation of the upper Zeeman component of the ground state by laser-related heating effects, and are of some help in optimizing activated material parameters to suppress the multiphonon-assisted Stokes fluorescence.Comment: 8 pages, 5 figure

Feedback cooling of the normal modes of a massive electromechanical system to submillikelvin temperature

We apply a feedback cooling technique to simultaneously cool the three electromechanical normal modes of the ton-scale resonant-bar gravitational wave detector AURIGA. The measuring system is based on a dc Superconducting Quantum Interference Device (SQUID) amplifier, and the feedback cooling is applied electronically to the input circuit of the SQUID. Starting from a bath temperature of 4.2 K, we achieve a minimum temperature of 0.17 mK for the coolest normal mode. The same technique, implemented in a dedicated experiment at subkelvin bath temperature and with a quantum limited SQUID, could allow to approach the quantum ground state of a kilogram-scale mechanical resonator.Comment: 4 pages, 4 figure

18F-FDG PET-Derived Volume-Based Parameters to Predict Disease-Free Survival in Patients with Grade III Breast Cancer of Different Molecular Subtypes Candidates to Neoadjuvant Chemotherapy

We investigated whether baseline [F-18] Fluorodeoxyglucose (F-18-FDG) positron emission tomography (PET)-derived semiquantitative parameters could predict disease-free survival (DFS) in patients with grade III breast cancer (BC) of different molecular subtypes candidate to neoadjuvant chemotherapy (NAC). For each F-18-FDG-PET/CT scan, the following parameters were calculated in the primary tumor (SUVmax, SUVmean, MTV, TLG) and whole-body (WB_SUVmax, WB_MTV, and WB_TLG). Receiver operating characteristic (ROC) analysis was used to determine the capability to predict DFS and find the optimal threshold for each parameter. Ninety-five grade III breast cancer patients with different molecular types were retrieved from the databases of the University Hospital of Padua and the University Hospital of Ferrara (luminal A: 5; luminal B: 34; luminal B-HER2: 22; HER2-enriched: 7; triple-negative: 27). In luminal B patients, WB_MTV (AUC: 0.75; best cut-off: WB_MTV > 195.33; SS: 55.56%, SP: 100%; p = 0.002) and WB_TLG (AUC: 0.73; best cut-off: WB_TLG > 1066.21; SS: 55.56%, SP: 100%; p = 0.05) were the best predictors of DFS. In luminal B-HER2 patients, WB_SUVmax was the only predictor of DFS (AUC: 0.857; best cut-off: WB_SUVmax > 13.12; SS: 100%; SP: 71.43%; p < 0.001). No parameter significantly affected the prediction of DFS in patients with grade III triple-negative BC. Volume-based parameters, extracted from baseline F-18-FDG PET, seem promising in predicting recurrence in patients with grade III luminal B and luminal B- HER2 breast cancer undergoing NAC

Trunk Restraint Therapy: The Continuous Use Of The Harness Could Promote Feedback Dependence In Poststroke Patients: A Randomized Trial.

The objective of this study was to evaluate the long-term effects of the task-specific training with trunk restraint compared with the free one in poststroke reaching movements. The design was randomized trial. The setting was University of Campinas (Unicamp). Twenty hemiparetic chronic stroke patients were selected and randomized into 2 training groups: trunk restraint group (TRG) (reaching training with trunk restraint) and trunk free group (TFG) (unrestraint reaching). Twenty sessions with 45 minutes of training were accomplished. The patients were evaluated in pretreatment (PRE), posttreatment (POST) and 3 months after the completed training (RET) (follow-up). Main outcome measures were modified Ashworth scale, Barthel index, Fugl-Meyer scale, and kinematic analysis (movement trajectory, velocity, angles). A significant improvement, which maintained in the RET test, was found in the motor (P < 0.001) and functional (P = 0.001) clinical assessments for both groups. For trunk displacement, only TFG obtained a reduction statistical significance from PRE to the POST test (P = 0.002), supporting this result in the RET test. Despite both groups presenting a significant increase in the shoulder horizontal adduction (P = 0.003), only TRG showed a significant improvement in the shoulder (P = 0.001--PRE to POST and RET) and elbow (P = 0.038--PRE to RET) flexion extension, and in the velocity rate (P = 0.03--PRE to RET). The trunk restraint therapy showed to be a long-term effective treatment in the enhancement of shoulder and elbow active joint range and velocity rate but not in the maintenance of trunk retention. Trial registration: NCT02364141.94e64

Axion search with a quantum-limited ferromagnetic haloscope

A ferromagnetic axion haloscope searches for Dark Matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter YIG spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin-magnetometer ever realized. The minimum detectable field is $5.5\times10^{-19}\,$T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant $g_{aee}\le1.7\times10^{-11}$ at 95% CL. The scientific run of our haloscope resulted in the best limit on DM-axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion mass range $42.4$-$43.1\,\mu$eV. This is also the first apparatus to perform an axion mass scanning by changing the static magnetic field.Comment: 4 pages, 4 figure

Timing with resonant gravitational wave detectors: An experimental test

We measure the time of arrival ${t}_{0}$ of a force signal acting on a room temperature gravitational wave antenna. The antenna has a noise spectral density whose shape is a rescaled replica of that predicted for the two subkelvin antennas located in Italy, once at their sensitivity goal. ${t}_{0}$ is expressed as {t}_{0}{=t}_{\ensuremath{\varphi}}{+kT}_{0} where ${T}_{0}$ is half the natural period of oscillation of the antenna, |{t}_{\ensuremath{\varphi}}|l~{T}_{0}/2, and $k$ is an integer. We measure the phase part {t}_{\ensuremath{\varphi}} with an accuracy of {\ensuremath{\sigma}}_{{t}_{\ensuremath{\varphi}}}\ensuremath{\approx}174\mathrm{\ensuremath{\mu}}\mathrm{s}/\mathrm{S}\mathrm{N}\mathrm{R}, where SNR is the signal to noise ratio for the signal amplitude. We also find that, for $\mathrm{SNR}g~20,$ the error on $k$ is \ensuremath{\delta}k\ensuremath{\ll}1 so that the total statistical error on the arrival time reduces to the phase error {\ensuremath{\sigma}}_{{t}_{\ensuremath{\varphi}}}. We discuss how this last result can be achieved even for smaller values of the SNR, by better tuning the modes of the antenna. We finally discuss the relevance of these results for source location and spuria events rejection with the two subkelvin detectors above