Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Chlorin endogenous to the north pacific brittle star ophiura sarsii for photodynamic therapy applications in breast cancer and glioblastoma models

Photodynamic therapy (PDT) represents a powerful avenue for anticancer treatment. PDT relies on the use of photosensitizers—compounds accumulating in the tumor and converted from benign to cytotoxic upon targeted photoactivation. We here describe (3S,4S)-14-Ethyl-9-(hydroxymethyl)-4,8,13,18-tetramethyl-20-oxo-3-phorbinepropanoic acid (ETPA) as a major metabolite of the North Pacific brittle stars Ophiura sarsii. As a chlorin, ETPA efficiently produces singlet oxygen upon red-light photoactivation and exerts powerful sub-micromolar phototoxicity against a panel of cancer cell lines in vitro. In a mouse model of glioblastoma, intravenous ETPA injection combined with targeted red laser irradiation induced strong necrotic ablation of the brain tumor. Along with the straightforward ETPA purification protocol and abundance of O. sarsii, these studies pave the way for the development of ETPA as a novel natural product-based photodynamic therapeutic