Observation of a Nuclear Recoil Peak at the 100 eV Scale Induced by Neutron Capture

Coherent elastic neutrino-nucleus scattering and low-mass dark matter detectors rely crucially on the understanding of their response to nuclear recoils. We report the first observation of a nuclear recoil peak at around 112 eV induced by neutron capture. The measurement was performed with a CaWO_{4} cryogenic detector from the NUCLEUS experiment exposed to a ^{252}Cf source placed in a compact moderator. We identify the expected peak structure from the single-γ de-excitation of ^{183}W with 3σ and its origin by neutron capture with 6σ significance. This result demonstrates a new method for precise, in situ, and nonintrusive calibration of low-threshold experiments.

Heart Failure With Cardiogenic Shock as a Manifestation of Untreated POEMS (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal Protein, Skin Changes) Syndrome

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) is a rare paraneoplastic syndrome due to a plasma cell disorder. Diagnosis requires peripheral neuropathy and a monoclonal plasma cell disorder along with one major and one minor criteria, but cardiac manifestations are uncommon. The pathogenesis of POEMS syndrome is not well understood but it is thought to involve overproduction of proinflammatory cytokines, such as vascular endothelial growth factor (VEGF), interleukin-1 beta (IL-1B), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha). POEMS syndrome commonly presents in the fifth to sixth decade of life, mainly in non-Hispanic Caucasian individuals, and affects more men than women (2:1). We report a unique case of a 28-year-old African American female with a history of POEMS syndrome and a new diagnosis of dilated, non-ischemic cardiomyopathy and New York Heart Association (NYHA) class IV, stage D heart failure with an ejection fraction (EF) of 30% as a result of the natural progression of her untreated POEMS syndrome.