IntroductionThe Alzheimer's biomarkers in daily practice (ABIDE) project is designed to translate knowledge on diagnostic tests (magnetic resonance imaging [MRI], cerebrospinal fluid [CSF], and amyloid positron emission tomography [PET]) to daily clinical practice with a focus on mild cognitive impairment (MCI)MethodsABIDE is a 3-year project with a multifaceted design and is structured into interconnected substudies using both quantitative and qualitative research methods.ResultsBased on retrospective data, we develop personalized risk estimates for MCI patients. Prospectively, we collect MRI and CSF data from 200 patients from local memory clinics and amyloid PET from 500 patients in a tertiary setting, to optimize application of these tests in daily practice. Furthermore, ABIDE will develop strategies for optimal patient-clinician conversations.DiscussionUltimately, this will result in a set of practical tools for clinicians to support the choice of diagnostic tests and facilitate the interpretation and communication of their results.

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Metamaterials provide an unprecedented ability to manipulate electromagnetic waves and are an enabling technology for new devices ranging from flat lenses that focus light beyond the diffraction limit to coatings capable of cloaking an object. Nevertheless, narrow bandwidths and high intrinsic losses arising from the resonant properties of metamaterials have raised doubts about their usefulness. New design approaches seek to turn the perceived disadvantages of dispersion into assets that enhance a device's performance. Here we employ dispersion engineering of metamaterial properties to enable specific device performance over usable bandwidths. In particular, we design metamaterials that considerably improve conventional horn antennas over greater than an octave bandwidth with negligible loss and advance the state of the art in the process. Fabrication and measurement of a metahorn confirm its broadband, low-loss performance. This example illustrates the power of clever implementation combined with dispersion engineering to bring metamaterials into their full potential for revolutionizing practical devices.

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Cyclotron production of 99m Tc is a promising route to supply 99m Tc radiopharmaceuticals. Higher 99m Tc yields can be obtained with medium-energy cyclotrons in comparison to those dedicated to PET isotope production. To take advantage of this capability, evaluation of the radioisotopic purity of 99m Tc produced at medium energy (20)(21)(22)(23)(24) and its impact on image quality and dosimetry was required. Methods: Thick 100 Mo (99.03% and 99.815%) targets were irradiated with incident energies of 20, 22, and 24 MeV for 2 or 6 h. The targets were processed to recover an effective thickness corresponding to approximately 5-MeV energy loss, and the resulting sodium pertechnetate 99m Tc was assayed for chemical, radiochemical, and radionuclidic purity. Radioisotopic content in final formulation was quantified using g-ray spectrometry. The internal radiation dose for 99m Tc-pertechnetate was calculated on the basis of experimentally measured values and biokinetic data in humans. Planar and SPECT imaging were performed using thin capillary and water-filled Jaszczak phantoms. Results: Extracted sodium pertechnetate 99m Tc met all provisional quality standards. The formulated solution for injection had a pH of 5.0−5.5, contained greater than 98% of radioactivity in the form of pertechnetate ion, and was stable for at least 24 h after formulation. Radioisotopic purity of 99m Tc produced with 99.03% enriched 100 Mo was greater than 99.0% decay corrected to the end of bombardment (EOB). The radioisotopic purity of 99m Tc produced with 99.815% enriched 100 Mo was 99.98% or greater (decay corrected to the EOB). The estimated dose increase relative to 99m Tc without any radionuclidic impurities was below 10% for sodium pertechnetate 99m Tc produced from 99.03% 100 Mo if injected up to 6 h after the EOB. For 99.815% 100 Mo, the increase in effective dose was less than 2% at 6 h after the EOB and less than 4% at 15 h after the EOB when the target was irradiated at an incident energy of 24 MeV. Image spatial resolution and contrast with cyclotron-produced 99m Tc were equivalent to those obtained with 99m Tc eluted from a conventional generator. Conclusion: Clinical-grade sodium pertechnetate 99m Tc was produced with a cyclotron at medium energies. Quality control procedures and release specifications were drafted as part of a clinical trial application that received approval from Health Canada. The results of this work are intended to contribute to establishing a regulatory framework for using cyclotron-produced 99m Tc in routine clinical practice. The radioisotope 99m Tc remains indispensable in nuclear imaging. 99m Tc is usually obtained from generators containing the mother isotope, 99 Mo, which in turn is made from highly enriched 235 U ($20%, typically 93%) in nuclear reactors. 99m Tc is eluted in the form of sodium pertechnetate and can be used as is or as the starting material for other 99m Tc radiopharmaceuticals used in a variety of diagnostic applications. Cyclotron production of 99m Tc could be a viable alternativ...