Metal-organic frameworks (MOFs) define emerging materials with unique optoelectronic properties that stem from the highly organized chromophoric linkers within their frameworks. The extent of ground- and excited-state interchromophoric interaction among the π-conjugated macrocyclic linkers was studied within three tetraphenyl-pyrene (1,3,6,8-tetrakis(p-benzoic acid)pyrene; HTBAPy)-based MOFs: ROD-7 (In(OH)TBAPy, frz), NU-901 (scu), and NU-1000 (csq) via steady-state and time-resolved spectroscopic techniques. These experimental data along with computational results indicate that the extent of the interchromophoric interaction, leading to a reduced optical band gap, varies across the series of MOFs and is a function of the relative orientation of the TBAPy linkers determined by their respective framework topology. The trend in the S → S emission lifetime is consistent with their relative optical bandgap. Analyses of the transient emission decay profiles and time-resolved emission spectroscopic data, recorded in low dielectric media, reveal that a long-lived emissive excimer state appears ∼1850 ± 150 cm lower in energy relative to their corresponding S → S transitions. The emissive contribution from this excimer state, as well as its corresponding transition energy and time constants, are also found to be dependent on MOF identity. Such variation in properties are particularly influenced by the number density of the TBAPy linkers presented by the topology of a given MOF that are primed to form such an excited state complex. The present work shows how the specific arrangement of the linkers can play a key role in the photophysical properties of MOFs.

Highly ordered chromophoric linkers positioned within the metal-organic frameworks (MOFs) have the potential to mimic natural light-harvesting complexes. Herein we report topological control over the photophysical properties of MOFs via modular interchromophoric electronic coupling to manifest different steady-state singlet emission spectra and their corresponding fluorescence lifetimes.

Background: The potassium channel encoded by the ether-a-gogo-related gene 1A (erg1a) has been detected in the atrophying skeletal muscle of mice experiencing either muscle disuse or cancer cachexia and further evidenced to contribute to muscle deterioration by enhancing ubiquitin proteolysis; however, to our knowledge, ERG1A has not been reported in human skeletal muscle. Methods and Results: Here, using immunohistochemistry, we detect ERG1A immunofluorescence in human Rectus abdominis skeletal muscle sarcolemma. Further, using single point brightness data, we report the detection of ERG1A immunofluorescence at low levels in the Rectus abdominis muscle sarcolemma of young adult humans and show that it trends toward greater levels (10.6%) in healthy aged adults. Interestingly, we detect ERG1A immunofluorescence at a statistically greater level (53.6%; p < 0.05) in the skeletal muscle of older cancer patients than in age-matched healthy adults. Importantly, using immunoblot, we reveal that lower mass ERG1A protein is 61.5% (p < 0.05) more abundant in the skeletal muscle of cachectic older adults than in healthy age-matched controls. Additionally, we report that the ERG1A protein is detected in a cultured human rhabdomyosarcoma line that may be a good in vitro model for the study of ERG1A in muscle. Conclusions: The data demonstrate that ERG1A is detected more abundantly in the atrophied skeletal muscle of cancer patients, suggesting it may be related to muscle loss in humans as it has been shown to be in mice experiencing muscle atrophy as a result of malignant tumors.

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Studies of the Caribbean herpetofauna (amphibians and reptiles) have made significant contributions to our knowledge of evolutionary patterns and processes. A prerequisite for these studies are accurate taxonomies and robust phylogenetic hypotheses. One notable Caribbean radiation lacking such data are dwarf geckos of the genus Sphaerodactylus. Systematics of the Puerto Rican Sphaerodactylus have been turbulent since the initial species descriptions and no molecular phylogenies exist that include complete or near-complete taxon sampling. Here, we combine a multi-locus molecular phylogeny with extensive morphological information to investigate the current diversity of Sphaerodactylus geckos from the Puerto Rican Bank, with a large number of species from Hispaniola as an outgroup. In particular, we focus our efforts on resolving the taxonomy of the Sphaerodactylus macrolepis Günther species complex. We find S. macrolepis sensu lato (currently two nominal species with nine subspecies) is made up of at least four diagnosable species within two clades: (1) the sister species Sphaerodactylus macrolepis sensu stricto from the Virgin Islands (including St. Croix) and Culebra, and S. parvus King from islands in the northern Lesser Antilles; and (2) all other Sphaerodactylus macrolepis subspecies from Puerto Rico, Vieques, and Culebra. We resurrect Sphaerodactylus grandisquamis Stejneger from synonymy to refer to all subspecies from Puerto Rico and elevate the subspecies Sphaerodactylus inigoi Thomas & Schwartz for geckos from Vieques and western Culebra. The resulting phylogeny and revised taxonomy will be a useful tool for subsequent research into Sphaerodactylus conservation and evolution.