Marquette University Slavic Institute Papers NO. 11

https://epublications.marquette.edu/mupress-book/1011/thumbnail.jp

Characterization of the Electronic Excited-State Energetics and Solution Structure of Lanthanide(III) Complexes with the Polypyridine Ligand 6,6\u27-Bis[bis(2-pyridylmethyl)aminomethyl]-2,2\u27-bipyridine

Absorption, emission, and excitation spectra for solid-state and solution of Tb(III), Dy(III), and Gd(III) complexes with the polypyridine ligand 6,6‘-bis[bis(2-pyridylmethyl)-aminomethyl]-2,2‘-bipyridine (C36H34N8) are presented. Measurements of excited-state lifetimes and quantum yields in various solvents at room temperature and 77 K are also reported and used to characterize the excited-state energetics of this system. Special attention is given to the characterization of metal-to-ligand energy transfer efficiency and mechanisms. The measurement of circularly polarized luminescence (CPL) from the solution of the Dy(III) complex following circularly polarized excitation confirms the chiral structure of the complexes under study. No CPL is present in the luminescence from the Eu(III) or Tb(III) complex because of efficient racemization. The variation of the magnitude of the CPL as a function of temperature from an aqueous solution of DyL is used for the first time to characterize the solution equilibria between different chiral species

Assessing environmentally effective post‑COVID green recovery plans for reducing social and economic inequality

Given the current environmental crisis there have been multiple calls for a green recovery from COVID-19 which address environmental concerns and provide jobs in industries and communities economically damaged by the pandemic. Here, we holistically evaluate a range of recovery scenarios, evaluated on environmental and socio-economic equity metrics. Using a modified version of a Bayesian belief network, we show that economic stimuli across green sectors, including jobs in renewable energy, waste management, retrofitting of buildings, heat-pump installation and public transport can help economic growth, but will have limited environmental benefits. The inclusion of carbon taxes and ending fossil fuel subsidies, alongside investment in nature-based solutions and jobs in ecological conservation, can greatly increase the environmental gains as well as socio-economic equality. Additionally, jobs not associated with green industries, but with low carbon footprints, such as those in social care can further improve social equality with minimal negative environmental effects. However, in these latter scenarios involving taxation and ending fossil fuel subsidies, economic growth is reduced. We suggest a comprehensive green recovery and green new deal are needed, and we should reimagine economies, without the focus on economic growth

Multiplex Cytological Profiling Assay to Measure Diverse Cellular States

Computational methods for image-based profiling are under active development, but their success hinges on assays that can capture a wide range of phenotypes. We have developed a multiplex cytological profiling assay that “paints the cell” with as many fluorescent markers as possible without compromising our ability to extract rich, quantitative profiles in high throughput. The assay detects seven major cellular components. In a pilot screen of bioactive compounds, the assay detected a range of cellular phenotypes and it clustered compounds with similar annotated protein targets or chemical structure based on cytological profiles. The results demonstrate that the assay captures subtle patterns in the combination of morphological labels, thereby detecting the effects of chemical compounds even though their targets are not stained directly. This image-based assay provides an unbiased approach to characterize compound- and disease-associated cell states to support future probe discovery

An image analysis toolbox for high-throughput C. elegans assays

We present a toolbox for high-throughput screening of image-based Caenorhabditis elegans phenotypes. The image analysis algorithms measure morphological phenotypes in individual worms and are effective for a variety of assays and imaging systems. This WormToolbox is available through the open-source CellProfiler project and enables objective scoring of whole-worm high-throughput image-based assays of C. elegans for the study of diverse biological pathways that are relevant to human disease.National Institutes of Health (U.S.) (U54 EB005149

Enhanced luminescence of Tb3+Tb^{3+} due to efficient energy transfer from Ce3+Ce^{3+} in a nanocrystalline Lu2Si2O7Lu_{2}Si_{2}O_{7} host lattice

Nanocrystalline lutetium pyrosilicate Lu(2)Si(2)O(7) (LPS) doped with Tb(3+) (LPS:Tb) or Ce(3+)/Tb(3+) (LPS:Ce, Tb) was obtained at 1250 °C by the reaction of nanostructured Lu(2)O(3) and colloidal SiO(2). X-ray diffraction analysis confirmed the crystallization of a single phase of LPS at the indicated temperature. Different concentrations of active ions allowed us to study the influence of Ce(3+) co-doping on Tb(3+) emission. Tb(3+)-doped LPS yields both the blue emission [Formula: see text] (J = 3, 4, 5, 6) and the green emission [Formula: see text] (J = 3, 4, 5, 6) of Tb(3+). The green emission of Tb(3+) is enhanced remarkably in both the cathodoluminescence and photoluminescence spectra because of energy transfer from Ce(3+) to Tb(3+) ions, both of which are present in the host lattice. Based on the optical luminescence and luminescence excitation spectra, the optimal Tb(3+) doping level for maximum light output was established to be 9 mol% and the highest enhancement of Tb(3+) luminescence by Ce(3+) co-doping was detected using a 1:3 ratio of Ce(3+)/Tb(3+) concentration. Two different crystallographic sites of Tb(3+) in the LPS lattice were detected in the luminescence and excitation spectra of samples with higher Tb(3+) concentrations (6-9 mol%). The single-exponential decay profile of (5)D(4) emission for the less concentrated samples and the double-exponential decay for the higher doping level are in agreement with this observation. Calculation of colour coordinates shows that LPS:Ce(0.25%)Tb(3%) emits white light