We used deep-learning-based models to automatically obtain elastic moduli from resonant ultrasound spectroscopy (RUS) spectra, which conventionally require user intervention of published analysis codes. By strategically converting theoretical RUS spectra into their modulated fingerprints and using them as a dataset to train neural network models, we obtained models that successfully predicted both elastic moduli from theoretical test spectra of an isotropic material and from a measured steel RUS spectrum with up to 9.6% missing resonances. We further trained modulated fingerprint-based models to resolve RUS spectra from yttrium–aluminum-garnet (YAG) ceramic samples with three elastic moduli. The resulting models were capable of retrieving all three elastic moduli from spectra with a maximum of 26% missing frequencies. In summary, our modulated fingerprint method is an efficient tool to transform raw spectroscopy data and train neural network models with high accuracy and resistance to spectra distortion.
Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
Abstract -
Staphylococcus aureus uses small peptides to assess its population densisty ( i.e. , quorum sensing) and regulate virulence at high cell number. Here, we report the design and synthesis of peptidomimetics based on these native signals that strongly block this communication pathway in all four specificity groups of S. aureus .more » « less
-
Abstract By combining tandem asymmetric gold catalysis and subsequent stereoconvergent hydrolysis of enol ester in a one‐pot process, hydroxylated propargylic esters are converted into chiral β‐oxygenated ketones with mostly good enantiomeric ratios and in largely good to excellent yields. The product chiral center is formed via stereoselective cyclization of a hydroxylated allenyl ester intermediate, which is enabled by asymmetric gold‐ligand cooperation.
-
Abstract By employing a chiral bifunctional phosphine ligand, a gold(I)‐catalyzed efficient and highly enantioselective dearomatization of phenols is achieved via versatile metal‐ligand cooperation. The reaction is proven to be remarkably general in scope, permitting substitutions at all four remaining benzene positions, accommodating electron‐withdrawing groups including strongly deactivating nitro, and allowing carbon‐based groups of varying steric bulk including
tert ‐butyl at the alkyne terminus. Moreover, besidesN‐ (o ‐hydroxyphenyl)alkynamides, the corresponding ynoates and ynones are all suitable substrates. Spirocyclohexadienone‐pyrrol‐2‐ones, spirocyclohexadienone‐butenolides, and spirocyclohexadenone‐cyclopentenones are formed in yields up to 99 % and with ee up to 99 %. -
Abstract By employing a chiral bifunctional phosphine ligand, a gold(I)‐catalyzed efficient and highly enantioselective dearomatization of phenols is achieved via versatile metal‐ligand cooperation. The reaction is proven to be remarkably general in scope, permitting substitutions at all four remaining benzene positions, accommodating electron‐withdrawing groups including strongly deactivating nitro, and allowing carbon‐based groups of varying steric bulk including
tert ‐butyl at the alkyne terminus. Moreover, besidesN‐ (o ‐hydroxyphenyl)alkynamides, the corresponding ynoates and ynones are all suitable substrates. Spirocyclohexadienone‐pyrrol‐2‐ones, spirocyclohexadienone‐butenolides, and spirocyclohexadenone‐cyclopentenones are formed in yields up to 99 % and with ee up to 99 %. -
Abstract Staphylococcus aureus is a ubiquitous bacterium that has become a major threat to human health due to its extensive toxin production and tremendous capacity for antibiotic resistance (e. g., MRSA “superbug” infections). Amid a worsening antibiotic resistance crisis, new strategies to combat this deadly microbe that remove the selective pressure of traditional approaches are in high demand.S. aureus utilizes an accessory gene regulator (agr ) quorum sensing network to monitor its local cellular population and trigger a devastating communal attack, like an invading horde, once a threshold cell density has been reached. The role of theagr system in a range of disease types is still being unraveled. Herein, we discuss the present‐day biochemical understanding ofagr along with unresolved details, describe its connection to the progression of infection, and review how chemical strategies have been implemented to study and intercept this signaling pathway. This research is illuminating the potential ofagr as an anti‐virulence target inS. aureus and should inform the study of similar, yet less studied,agr systems in related bacterial pathogens. -
Abstract A gold(I)‐catalyzed enantioselective dearomatization is achieved via metal‐chiral ligand cooperation. A new and divergent synthesis of chiral bifunctional binaphthyl‐2‐ylphosphines is developed to allow rapid access to these ligands, which in turn facilitate the application of this chemistry to a broad substrate scope including 1‐naphthols, 2‐naphthols, and phenols. Enantiomeric excesses up to 98 % are achieved via selective acceleration of one enantiomer formation enabled by hydrogen bonding between substrate and ligand remote basic group. DFT calculations lend support to the cooperative catalysis and substantiate the reaction stereochemical outcomes.
-
Abstract A gold(I)‐catalyzed enantioselective dearomatization is achieved via metal‐chiral ligand cooperation. A new and divergent synthesis of chiral bifunctional binaphthyl‐2‐ylphosphines is developed to allow rapid access to these ligands, which in turn facilitate the application of this chemistry to a broad substrate scope including 1‐naphthols, 2‐naphthols, and phenols. Enantiomeric excesses up to 98 % are achieved via selective acceleration of one enantiomer formation enabled by hydrogen bonding between substrate and ligand remote basic group. DFT calculations lend support to the cooperative catalysis and substantiate the reaction stereochemical outcomes.