With excellent energy resolution and ultralow-level radiogenic backgrounds, the high-purity germanium detectors in the Majorana Demonstrator enable searches for several classes of exotic dark matter (DM) models. In this work, we report new experimental limits on keV-scale sterile neutrino DM via the transition magnetic moment from conversion to active neutrinos ν_{s}→ν_{a}. We report new limits on fermionic dark matter absorption (χ+A→ν+A) and sub-GeV DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), and new exclusion limits for bosonic dark matter (axionlike particles and dark photons). These searches utilize the (1-100)-keV low-energy region of a 37.5-kg y exposure collected by the Demonstrator between May 2016 and November 2019 using a set of ^{76}Ge-enriched detectors whose surface exposure time was carefully controlled, resulting in extremely low levels of cosmogenic activation.
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http://dx.doi.org/10.1103/PhysRevLett.132.041001 | DOI Listing |
Sci Rep
December 2024
Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, USA.
Coral reef sponges efficiently take up particulate and dissolved organic matter (DOM) from the water column and release compounds such as nucleosides, amino acids, and other dissolved metabolites to the surrounding reef via their exhalent seawater, but the influence of this process on reef picoplankton and nutrient processing is relatively unexplored. Here we examined the impact of sponge exhalent on the reef picoplankon community and subsequent alterations to the reef dissolved metabolite pool. We exposed reef picoplankton communities to a sponge exhalent water mixture (Niphates digitalis and Xestospongia muta) or filtered reef seawater (control) in closed, container-based dark incubations.
View Article and Find Full Text PDFActa Neurol Belg
December 2024
Lamezia Terme Hospital, Catanzaro, Italy.
Curr Issues Mol Biol
December 2024
Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Canine mammary carcinomas (CMCs) represent the most prevalent form of cancer in female dogs, characterized by a high incidence and mortality rate. C6 ceramide is recognized for its multifaceted anti-cancer properties, yet its specific influence on CMCs remains to be elucidated. Long noncoding RNAs (lncRNAs), now recognized as functional "dark matter" in precision oncology, are particularly intriguing, with 44% of canine lncRNAs exhibiting tissue-specific expression.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemical Sciences and Center for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, West Bengal, India.
Triple-negative breast cancer (TNBC) poses significant treatment challenges due to its high metastasis, heterogeneity, and poor biomarker expression. The N-terminus of an octapeptide NAPVSIPQ () was covalently coupled to a carboxylic acid derivative of Ru(2,2'-bipy) () to synthesize an N-stapled short peptide-Rubpy conjugate (). This photosensitizer (PS) was utilized to treat TNBC through microtubule (MT) targeted chemotherapy and photodynamic therapy (PDT).
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Department of Physics, Kyungpook National University, Daegu 41566, Republic of Korea.
We give for the first time theoretical estimates of unknown rare electron-capture (EC) decay branchings of ^{44}Ti, ^{57}Co, and ^{139}Ce, relevant for searches of (exotic) dark-matter particles. The nuclear-structure calculations have been done exploiting the nuclear shell model with well-established Hamiltonians and an advanced theory of β decay. In the absence of experimental measurements of these rare branches, these estimates are of utmost importance for terrestrial searches of dark-matter particles, such as axionic dark matter in the form of axionlike particles, anapole dark matter, and dark photons in nuclear transitions.
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