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A Tale of Two Isomers: Enhanced Antiaromaticity/Diradical Character versus Deleterious Ring-Opening

Fusion of benzofuran to hydrocarbon cores results in two dramatically different outcomes depending upon heterocycle orientation. Whereas the “anti” isomers are unstable and afford ring-opened products, the “syn” isomers are stable, giving molecules that either possess a high degree of antiaromaticity or exhibit pronounced diradical character.

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Sphere packing is mechanically stable at zero density

High strength-to-weight ratio materials can be constructed by either maximizing strength or minimizing weight. Corwin lab researchers show that, even in the absence of attractive or tensile forces, one can construct mechanically rigid structures out of frictionless spheres that have vanishingly low density. This work points the way towards novel lightweight high-strength materials.

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Modular Ni(0)/Silane Catalytic System for the Isomerization of Alkenes

A dynamic and modular catalytic system based on (NHC)Ni(0) complexes and triaryl silanes is described for the isomerization of alkenes. Substrate reactivity is enhanced with different NHC ligand and silane combinations to achieve reactivity with a diverse set of alkenes. Featured as a cover to "Organometallics " February 16 2022

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Dynamic bond breaking and reforming in porous crystals, revealed

Metal-organic frameworks (MOFs) are the most porous materials in the universe. They have been so widely studied over the past 20 years, that 70,000 unique structures have been reported so far, and when designing their applications, they have always assumed to be static and rigid. The Brozek lab provides clear evidence of the contrary: that even as solid crystals, MOFs show dynamic bond breaking and reforming more akin to liquids and biological systems.

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Generation of X-ray vortex beams

A collaboration between the McMorran lab and researchers at the Advanced Light Source at Berkeley National Lab demonstrated the use of nanoscale holograms to produce structured x-ray beams. These x-ray beams show promise for use as probes of magnetism and electronic properties in materials.

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Jamming Energy Landscape is Hierarchical and Ultrametric

The Corwin lab has demonstrated that the structure of sandpiles is controlled by a fractally rough energy landscape. Each configuration of a sandpile is separated by infinitesimal energy barriers from a huge number of very similar configurations. This property leads to the novel mechanical behavior of sand piles and jammed systems in general.

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Emerging applications of carbon nanohoops

This review from the Jasti group highlights a multitude of recent studies that exploit unique carbon nanohoop properties towards applications ranging from biological imaging to organic electronics.

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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.

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Optimizing mass spectrometry for membrane protein complexes

The Prell Group at UO and Marty Group at the University of Arizona (lead authors) demonstrate that chemical additives added to aqueous buffers containing native-like membrane proteins embedded in lipoprotein "Nanodisc" membrane mimics can modulate the fate of these intricate complexes when transferred into a mass spectrometer. By choosing the right combination of chemical additive and instrumental settings, a remarkably flexible variety of target ions can be produce that enable researchers to study membrane protein complex stoichiometry, size and shape, and lipid binding.

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Imaging provides insights into the physical characteristics and spatial distributions of gut bacteria

Despite the importance of the gut microbiome to health and disease, little is known about these intestinal ecosystems are organized in time and space. Using three-dimensional microscopy of larval zebrafish, researchers in the Parthasarathy Lab were able to map the spatial distributions of several gut species, as well as the behaviors of individual bacteria. Surprisingly, they discovered a strong link between the two; the tendency of bacteria to aggregate is a very strong predictor of their location in the gut. This suggests the existence of general biophysical rules that can make sense of the gut microbiome.

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A path-separated electron interferometer within a conventional scanning transmission electron microscope.

From gravitational wave sensing, to fundamental quantum measurements, to imaging of transparent materials, interferometry has been used in as an investigative tool in many scientific fields. The McMorran Lab presents a path-separated electron interferometer that can potentially be applied to explore fundamental physics of nano-materials and as a phase contrast imaging technique.

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Selective Anion Receptors for Hydrogen Sulfate

The Haley and Johnson collaborative team prepared two hosts that selectively bind the anion hydrogen sulfate, a contaminant often found in agricultural and industrial waste streams. The team showed that the hosts can capture/transport this anion from an aqueous source under liquid-liquid extraction conditions.