Three pathological processes define or are characteristic of Alzheimer’s disease (AD): amyloid-β, hyperphosphorylated tau, and neurodegeneration. Our understanding of AD is undergoing a transformation due to our ability to measure biomarkers of these processes across different stages of cognitive impairment. There is growing interest in using AD biomarker tests in care and research and, with this, a growing need for guidance on how to return these sensitive results to patients and participants. Here, we propose a five-step approach informed by: clinical and research experience designing and implementing AD biomarker disclosure processes; extant evidence describing how individuals react to AD biomarker information; ethics; and the literature on breaking bad news. The clinician should (1) determine the appropriateness of AD biomarker testing and return of results for the particular patient or research participant. If testing is appropriate, the next steps are to: (2) provide pre-test education and seek consent for testing to the individual and their support person; (3) administer testing; (4) return the results to the individual and their support person; and (5) follow up to promote the recipient’s wellbeing and to learn from their experience. We conclude by identifying open questions to guide future studies of biomarker disclosure.

A staggering number of individuals live with cognitive decline. Primary care providers are ideally situated to detect the first signs of cognitive decline, but many persons remain undiagnosed. This limits their access to appropriate care. Unfortunately, the timely diagnosis of mild cognitive impairment or dementia in primary care is difficult to achieve. There is a great need for interventions to address this problem. This article applies an implementation science framework, the Behavioral Change Wheel, to evaluate the factors that influence detection of cognitive impairment in primary care and proposes candidate interventions for future study.

Chiral liquid crystals exhibit molecular optical activity in the isotropic phase. We have studied the evolution of the optical activity as a function of an applied electric field on a 7 6 . 2~ film of the chiral liquid crystal W7, which exhibits an isotropic-smectic A transition at approximately 40°C. We measured the optical activity by recording the rotation of the plane of polarization of an incident linearly polarized ray of light, provided by a He-Ne laser. The applied biasing electric field is parallel to the direction of the incident beam. We find that at 41.0°C, the plane of polarization shifts from -1.1" for an applied voltage of 30 V to a maximum of -4.0" at 70V. The absolute value of the signal decreases beyond this voltage. These shifts are in the direction of the smectic A phase and are in general larger than those observed as a function of temperature. Close to the isotropic-smectic A phase transition, molecules inside the liquid coalesce to form dynamic coherent groups, which have smectic nature. These groups are randomly oriented with respect to each other in the absence of an electric field. The application of an electric field causes the molecules within these groups to align along the direction of the field and to contribute coherently to the optical activity of the system. The way the molecules align with the field depends on the relative values of the polarizability a, which contributes to the alignment of the long axis ofthe molecule, and the dipole moment p, which contributes to the alignment of the short axis of the molecule. Our preliminary results and calculations suggest that for small fields, the electric field couples with the dipole moment p, whereas for fields in excess of 70V, the field couples with the polarizability of the long axis of the molecule, causing a rotational reorientation of the molecules in the isotropic phase. The value of the field at which this reorientation occurs may be controlled by temperature.

INTRODUCTIONThe effect of spinal versus general anesthesia on the risk of postoperative delirium or other outcomes for patients with or without cognitive impairment (including dementia) is unknown.METHODSPost hoc secondary analysis of a multicenter pragmatic trial comparing spinal versus general anesthesia for adults aged 50 years or older undergoing hip fracture surgery.RESULTSAmong patients randomized to spinal versus general anesthesia, new or worsened delirium occurred in 100/295 (33.9%) versus 107/283 (37.8%; odds ratio [OR] 0.85; 95% confidence interval [CI] 0.60 to 1.19) among persons with cognitive impairment and 70/432 (16.2%) versus 71/445 (16.0%) among persons without cognitive impairment (OR 1.02; 95% CI 0.71 to 1.47, p = 0.46 for interaction). Delirium severity, in‐hospital complications, and 60‐day functional recovery did not differ by anesthesia type in patients with or without cognitive impairment.DISCUSSIONAnesthesia type is not associated with differences in delirium and functional outcomes among persons with or without cognitive impairment.