Astrophysical molecular spectroscopy is an important method of searching for new physics through probing the variation of the proton-to-electron mass ratio, µ, with existing constraints limiting variation to a fractional change of less than 10 −17 /year. To improve on this constraint and therefore provide better guidance to theories of new physics, new molecular probes will be useful. These probes must have spectral transitions that are observable astrophysically and have different sensitivities to variation in the proton-to-electron mass ratio. Here, we concisely detail how astrophysical observations constrain the set of potential molecular probes and promising sensitive transitions based on how the frequency and intensity of these transitions align with available telescopes and observational constraints. Our detailed investigation focuses on rovibronic transitions in astrophysical diatomic molecules, using the spectroscopic models of 11 diatomics to identify sensitive transitions and probe how they generally arise in real complex molecules with many electronic states and fine structure. While none of the 11 diatomics investigated have sensitive transitions likely to be astrophysically observable, we have found that at high temperatures (1000 K) five of these diatomics have a significant number of low intensity sensitive transitions arising from an accidental near-degeneracy between vibrational levels in the ground and excited electronic state. This insight enables screening of all astrophysical diatomics as potential probes of proton-to-electron mass variation, with CN, CP, SiN and SiC being the most promising candidates for further investigation for sensitivity in rovibronic transitions.

This laboratory experiment provides a unique opportunity for instructors to present atomic absorption spectroscopy (AAS) in the context of bioremediation. Chemical technology students enrolled in an analytical instrumentation course successfully employed AAS to screen several types of biomass for the removal of copper from simulated wastewater. The experiment met technical course objectives while emphasis was placed on environmental stewardship and awareness.

SummaryChlorhexidine contamination of equipment used in central neuraxial anaesthesia has been implicated in causing adhesive arachnoiditis. We measured the extent of chlorhexidine splash during pouring into a gallipot (antiseptic skin preparation container) from heights of 5 cm, 10 cm, 15 cm and 20 cm. Twenty experiments were performed at each height. Measurements made up to a horizontal distance of 40 cm radius from the gallipot showed a median (IQR [range]) maximum spread of splash droplets ≥ 2 mm diameter of 26.2 (10.2-36.4 [0-40]) cm. The 40-cm radius measurement area was divided into 5-cm-wide zones to assess spread. At pouring heights of 15 cm and 20 cm, all zones were contaminated. These results demonstrate that pouring chlorhexidine into a gallipot generates significant splash, and we recommend that this should be avoided near equipment used for neuraxial anaesthesia.

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Retinoblastoma (RB) protein is a tumor suppressor that represses the transcriptional activity of E2Fs by forming an RB-E2F repressor complex. The phosphorylation of RB by CDK4/6 results in dissociation of the complex and subsequent E2F transcriptional activity, leading to cell cycle progression. RB loss occurs in 10-15% of castration-resistant prostate cancer (CRPC) which is associated tumor aggressiveness and poor clinical outcomes. RB loss is also associated differential treatment response to an array of treatment modalities, including hormone therapy and DNA damage inducing chemotherapy. RB depletion leads to enhanced expression of DNA repair proteins due to increased transcriptional activity of E2F1. PARP-1 is an enzyme that plays a role in multiple nuclear processes including DNA repair, transcriptional regulation, and chromatin dynamics. Increased PARP-1 activity is associated with and correlates to poor clinical outcomes in CRPC. E2F1 transcriptional activity is supported by PARP enzymatic activity, but the consequences of the functional interaction between the RB/E2F axis and PARP remains an open line of inquiry, which may yield novel treatment strategies and/or biomarkers of response. Isogenic models of RB1 knockdown were used to evaluate the impact of RB loss on PARP enzymatic activity. PARP-1 protein increases upon RB1 depletion with a concomitant increase in PARP activity. Growth curve assays were conducted to examine the biological response to PARP inhibition in the isogenic models. Results suggest a differential response between control and RB1 depleted cells when treated with Olaparib. RB1depleted cells also exhibit differential PARP activity in response to treatment with the IC50 dose of Olaparib. Future studies have been designed to evaluate the impact of RB alteration and manipulation of PARP activity on biological and molecular processes that are governed by RB/E2F and PARP. Citation Format: Latese Evans, Moriah Cunningham, Jasibel Vasquez Gonzalez, Matthew Schiewer. Interplay between PARP and the RB/E2F axis in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr B063.