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An Improved Method for H2S Detection - Pluth Lab in JACS
Compounds that become fluorescent when hydrogen sulfide (H2S) is detected in the body have become important for studying the biological significance of this rotten egg-smelling gas. Unfortunately, these compounds also use up the H2S that it detects, which may have a profound impact on the physiological processes that utilize this important molecule. Recently, the Pluth Lab has developed an innovative method for H2S detection that replenishes H2S, providing the first example of analyte replacement in a reaction-based fluorescent probe.
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Modulating Paratropicity Strength in Diareno-fused Antiaromatics
Understanding and controlling the electronic structure of molecules is crucial when designing and optimizing new organic materials. The findings of this study from the Haley lab can be used to predict the properties of, and thus rationally target, new diareno-fused antiaromatic molecules for use as organic semiconductors.
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Prell Group introduces Collidoscope, a New Tool for Computing Ion Collisional Cross Sections
"Native" ion mobility-mass spectrometry is emerging as a powerful method for learning about the structure and dynamics of biomolecular complexes transferred gently from buffered solution into the gas phase. Nevertheless, comparing experimental results to model structures can be very challenging due to the high computational cost of accurately calculating the collisional cross section of an ion, which is a measurement of its shape and size. The Prell Group has recently published an article detailing a new, open-source computational tool ("Collidoscope") they developed to make this possible for extremely large complexes weighing a megaDalton or more.
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Modulation Doping in Metastable Heterostructures
Controlling carrier concentration is critical in many device applications and both chemical substitution and modulation doping have been used in industry. For most inorganic materials, very low doping efficiencies are observed as site occupancies depend on both thermodynamic and kinetic factors. The Dave Johnson Group demonstrates that we can make kinetically controlled site-specific substitutions in a series of compounds.
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Molecular Nanohoop Quantum Corrals
Controllable modification of metal surface electronic structure is essential for developing applications involving interfacial electron transfer. The Nazin and Jasti Labs used scanning tunneling microscopy to study cycloparaphenylenes (CPPs) on metal surfaces, finding unexpected "eye"-like electronic features in the center of individual hoop-shaped CPPs. These "eyes" are localized states formed by the confinement of surface electrons, with the CPPs acting as molecular electronic “corrals", suggesting an approach to robust, large-area modification of surface electronic structure.
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High-K Lanthanum Zirconium Oxide Thin Film Dielectrics from Aqueous Solution Precursors
Metal oxide thin films are critical components in a number of microelectronic applications. These nanomaterials are typically made using vapor-phase methods, but solution-phase methods are an attractive cost-efficient and scalable alternative. The Page Group reports an aqueous route to lanthanum zirconium oxide thin films and demonstrates their viability as MIS device components.
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Light-Activated COS/H2S Donation from Photocaged Thiocarbamates
Hydrogen sulfide (H2S) is an important biomolecule, and responsive chemical tools for its delivery are needed. Here the Pluth lab utilizes the photo-cleavable o-nitrobenzyl group to unmask caged thiocarbamates and to access photo-activated H2S releasing molecules. These donors function by the initial release of carbonyl sulfide (COS), which is quickly hydrolyzed to H2S by carbonic anhydrase (CA).
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The viscosity of the gut
The fluid interior of the intestine serves as a medium for the diffusion of nutrients and other molecules, and an environment in which gut microbes must navigate. Characterizing the physical properties of this fluid in living animals has proven difficult, however. The Parthasarathy Lab has developed new techniques making use of micro- and nano-particles, driven by thermal energy or magnetic fields, imaged inside living larval zebrafish.
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Quick Excited State Dynamics Measurements using a Single-Shot Transient Absorption Spectrometer
Transient absorption spectroscopy measures excited state dynamics, but is usually limited to static systems owing to long data collection times. In this paper, the Wong Lab presents a single-shot transient absorption spectrometer with a 45 ps pump-probe time range that lowers the data collection time to 8 s. This advance will enable the measurement of the excited state dynamics of systems that are not at structural equilibrium.
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Intestinal mechanics amplify weak antibiotics
To explore how sublethal levels of antibiotics can affect gut microbes, the Parthasarathy and Guillemin Labs applied 3D microscopy to gut bacteria in live zebrafish. Antibiotic-induced changes in the spatial aggregation of bacteria, coupled to the mechanical activity of the intestine, led to large drops in microbial populations. The findings reveal a mechanism by which antibiotic environmental contamination can have much stronger effects than would be predicted by test-tube experiments.
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First example of reversible binding of reactive biomolecule hydroselenide
A collaboration of the Johnson, Haley, and Pluth labs resulted in the first report of the reversible binding and detection of the highly reactive hydroselenide (HSe–) anion. The ability to sense HSe- is important because all forms of dietary selenium, an essential nutrient, are believed to be transformed into HSe- before further metabolism. The high reactivity of HSe-, however, makes it difficult to directly detect in biological systems.
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Turn-On Fluorescence of Small, Highly Strained Carbon Nanohoops
The optical properties of carbon nanohoops were precisely manipulated to change their photophysical properties, resulting in a new class of structures. Smaller nanohoops, which are more easily accessed, are now fluorescent and brighter. This is critical for exploiting this class of structures as new biological fluorophores, supramolecular sensors and novel optoelectronic materials.
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Disentangling signals in mass spectra of complex mixtures
This article describes the Prell Group's use of image and sound processing tools to simplify the interpretation of mass spectra for large molecules, including proteins and polymers. In "native" mass spectrometry, which aims to preserve and characterize high-order structure of biomolecules as they are transferred into the gas phase, signal due to attachment of sodium and other ions to the biomolecules can make the mass spectrum extremely difficult to interpret. The Prell Group's method circumvents this problem by treating the biomolecule signal like a singer performing in a noisy room, first detecting then filtering the signal out from the noisy background.