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Transition metal carbides have been long proposed as replacements for expensive Pt-group transition metals as heterogeneous catalysts for hydrogenation reactions, featuring similar or superior activities and selectivities. Combining experimental observations and theoretical calculations, we show that the hydrogenating capabilities of molybdenum carbide can be further improved by nanostructuring, as seen on MoC y nanoclusters anchored on an inert Au(111) support, revealing a more prominent role of Mo active sites in the easier H2 adsorption, dissociation, H adatom diffusion, and elongated chemisorbed H2 Kubas moieties formation when compared to the bulk δ-MoC(001) surface, thus explaining the observed stronger H2 interaction and the larger formation of CH x species, making these systems ideal to catalyze hydrogenation reactions.Biominerals are composite materials with inorganic and organic components. The latter provide insights into how organisms control mineralization and, if derived from micro/nannofossils, into past climates. Many calcifying organisms cannot be cultured or are extinct; the only materials available for their study are therefore complex environmental samples in which the organism of interest may only be a minor component. There is currently no method for characterizing the biomineral-associated organic material from single particles within such assemblages, so its compositional diversity is unknown. Focusing on coccoliths, we demonstrate that surface-enhanced Raman scattering microspectroscopy can be used to determine the origin and composition of fossil organic matter at the single-particle level in a heterogeneous micro/nannofossil assemblage. This approach may find applications in the study of micro/nannofossil assemblages and uncultivated species, providing evolutionary insights into the macromolecular repertoire involved in biomineralization.Atmospheric aerosols can exist as supersaturated (metastable) liquid or glassy states, with physical and chemical properties that are distinct from the solid or liquid phases. These unique properties of aerosols have substantial implications on climate and health effects. Direct investigations on metastable aerosols remain a challenge because any interfacial contact can cause heterogeneous nucleation. In this study, in situ Raman spectroscopic and Mie scattering imaging analysis is applied to metastable aerosols in the absence of physical contact using an environment-controlled electrodynamic balance (EDB). This has allowed a detailed study of the O-H stretching regions of the Raman spectrum, revealing evidence for the rearrangement of hydrogen-bonding structures of levitated aqueous citric acid (CA) and aqueous sucrose droplets at metastable liquid states. We found that carboxyl groups in a CA droplet yield distinctive dynamics of strong and weak hydrogen bonds, whereas hydroxyl groups in a sucrose droplet show correlated strong and weak interactions. Such effects are particularly important in a supersaturated solution. These results indicate that metastable liquid aerosols from different sources may exhibit distinct physical and chemical behavior.Clostridioides difficile is the leading cause of healthcare-associated infection in the U.S. and considered an urgent threat by the Centers for Disease Control and Prevention (CDC). Only two antibiotics, vancomycin and fidaxomicin, are FDA-approved for the treatment of C. difficile infection (CDI), but these therapies still suffer from high treatment failure and recurrence. Therefore, new chemical entities to treat CDI are needed. Trifluoromethylthio-containing N-(1,3,4-oxadiazol-2-yl)benzamides displayed very potent activities [sub-μg/mL minimum inhibitory concentration (MIC) values] against Gram-positive bacteria. Here, we report remarkable antibacterial activity enhancement via halogen substitutions, which afforded new anti-C. difficile agents with ultrapotent activities [MICs as low as 0.003 μg/mL (0.007 μM)] that surpassed the activity of vancomycin against C. difficile clinical isolates. The most promising compound in the series, HSGN-218, is nontoxic to mammalian colon cells and is gut-restrictive. In addition, HSGN-218 protected mice from CDI recurrence. Not only does this work provide a potential clinical lead for the development of C. difficile therapeutics but also highlights dramatic drug potency enhancement via halogen substitution.A pyrrolidine-mediated Knoevenagel-type reaction for highly stereoselective construction of novel α-halo-1,3-dienylsulfonyl fluorides was achieved in up to 100% Z-selectivity and high yields at room temperature from condensation of the readily available aldehydes and halomethanesulfonyl fluorides. This protocol provided a class of unique α-halo-1,3-dienylsulfonyl fluorides with wide scope and excellent functional group compatibility. [https://www.selleckchem.com/products/vu661013.html learn more] The α-halo-1,3-dienylsulfonyl fluorides were used as versatile building blocks in sulfur fluoride exchange click chemistry, Suzuki reaction, and Sonogashira reaction for the assembly of highly functionalized dienyl sulfonyl fluoride derivatives to be applied as covalent warheads for the discovery of new drugs.Our search for candidates for photosynthesis inhibitors is allowing us to report the effect of two acetogenins identified in Annona coriacea Mart. leaves, ACG-A and ACG-B, a non-adjacent bis-THF and a mono-THF types, respectively. This is an important class of natural products which presents biological properties such as anticancer, neurotoxic, larvicidal and insecticidal. However, this is only the second report associated to its herbicidal activity. Their mechanisms of action on the light reactions of the photosynthesis were elucidated by polarographic techniques. Compounds inhibited the noncyclic electron transport on basal, phosphorylating, and uncoupled conditions from H2 O to methyl viologen (MV); therefore, they act as Hill reaction inhibitors. Studies on fluorescence of chlorophyll a (ChL a) indicated that they inhibited the acceptor side of PSII between P680 and PQ-pool, exactly as the commercial herbicide DCMU does.NMR spectroscopy is a potent method for the structural and biophysical characterization of RNAs. The application of NMR spectroscopy is restricted in RNA size and most often requires isotope-labeled or even selectively labeled RNAs. Additionally, new NMR pulse sequences, such as the heteronuclear-detected NMR experiments, are introduced. We herein provide detailed protocols for the preparation of isotope-labeled RNA for NMR spectroscopy via in vitro transcription. This protocol covers all steps, from the preparation of DNA template to the transcription of milligram RNA quantities. Moreover, we present a protocol for a chemo-enzymatic approach to introduce a single modified nucleotide at any position of any RNA. Regarding NMR methodology, we share protocols for the implementation of a suite of heteronuclear-detected NMR experiments including 13 C-detected experiments for ribose assignment and amino groups, the CN-spin filter heteronuclear single quantum coherence (HSQC) for imino groups and the 15 N-detected band-selective excitation short transient transverse-relaxation-optimized spectroscopy (BEST-TROSY) experiment.