Mosskusk5293

In this Letter, we describe a simple, practical approach in which cheap CuI was used as a catalyst to introduce a gem-difluoro olefin onto simple electron-rich aniline derivatives in good yield via direct C-H functionalization and a subsequent HF elimination reaction. Detailed mechanistic studies point at a dual role of aniline derivatives in this reaction, which serve as a substrate and a basic promoter to trigger the HF elimination step.We report a heterometallic seed-mediated synthesis method for monodisperse penta-twinned Cu nanorods using Au nanocrystals as seeds. Elemental analyses indicate that resultant nanorods consist predominantly of copper with a gold content typically below 3 atom %. The nanorod aspect ratio can be readily adjusted from 2.8 to 13.1 by varying the molar ratio between Au seeds and Cu precursor, resulting in narrow longitudinal plasmon resonances tunable from 762 to 2201 nm. Studies of reaction intermediates reveal that symmetry-breaking is promoted by rapid nanoscale diffusion in Au-Cu alloys and the formation of a gold-rich surface. The growth pathway features coevolving shape and composition whereby nanocrystals become progressively enriched with Cu concomitant with nanorod growth. The availability of uniform colloidal Cu nanorods with widely tunable aspect ratios opens new avenues toward the synthesis of derivative one-dimensional metal nanostructures, and applications in surface-enhanced spectroscopy, bioimaging, and electrocatalysis, among others.Adenosine-to-inosine RNA editing is an enzymatic post-transcriptional modification which modulates immunity and neural transmission in multicellular organisms. In particular, it involves editing of mRNA codons with the resulting amino acid substitutions. We identified such sites for developmental proteomes of Drosophila melanogaster at the protein level using available data for 15 stages of fruit fly development from egg to imago and 14 time points of embryogenesis. In total, 40 sites were obtained, each belonging to a unique protein, including four sites related to embryogenesis. The interactome analysis has revealed that the majority of the editing-recoded proteins were associated with synaptic vesicle trafficking and actomyosin organization. Quantitation data analysis suggested the existence of a phase-specific RNA editing regulation with yet unknown mechanisms. These findings supported the transcriptome analysis results, which showed that a burst in the RNA editing occurs during insect metamorphosis from pupa to imago. Finally, targeted proteomic analysis was performed to quantify editing-recoded and genomically encoded versions of five proteins in brains of larvae, pupae, and imago insects, which showed a clear tendency toward an increase in the editing rate for each of them. These results will allow a better understanding of the protein role in physiological effects of RNA editing.In this work, we report a thorough investigation of the reaction of phenols with aryldiazoacetates. VU661013 molecular weight Mechanistic studies using different spectroscopic methods and theoretical calculations suggest a hydrogen bond between phenol and aryldiazoacetates, which can be modulated by the phenol acidity. The pKA of phenol and therefore the hydrogen bond plays an important role in a subsequent photoinduced proton transfer reaction to give the formal O-H functionalization product of phenols.Currently, researchers spend significant time manually searching through large volumes of data produced during scanning probe imaging to identify specific patterns and motifs formed via self-assembly and self-organization. Here, we use a combination of Monte Carlo simulations, general statistics, and machine learning to automatically distinguish several spatially correlated patterns in a mixed, highly varied data set of real AFM images of self-organized nanoparticles. We do this regardless of feature-scale and without the need for manually labeled training data. Provided that the structures of interest can be simulated, the strategy and protocols we describe can be easily adapted to other self-organized systems and data sets.Surface-enhanced Raman scattering (SERS) technique with naturally born analyte identification capability can achieve ultrahigh sensitivity. However, the sensitivity and quantification capability of SERS are assumed to be mutually exclusive. Here, we prohibit the formation of the ultrasensitive SERS sites to achieve a high quantification capability through separating the gold (Au) nanorods from approaching each other with thick metal organic framework (MOF) shells. The sensitivity decrease caused by the absence of the ultrasensitive SERS sites is compensated by the analyte enrichment function of a slippery surface. The porous MOF shell around the Au nanorod only allows analytes smaller than the pore size to approach the Au nanorods and contribute to the SERS spectrum within the complex sample, greatly enhancing the analyte identification capability. Overall, we have demonstrated an integrated SERS platform with analyte enrichment and analyte filtration function, realizing sensitive, quantitative, and size selective analyte identification in complex environments.Herein, we report on the palladium-catalyzed synthesis of trifluoromethylated, tetrasubstituted allenes from vinyl bromides and trifluoromethylated diazoalkanes in good to excellent yield. This reaction proceeds via oxidative addition of a Pd(0) complex with vinyl bromide. Subsequent base-promoted reductive elimination generates the allene. This methodology provides an efficient strategy even on gram scale to valuable trifluoromethylated, tetrasubstituted allenes under mild reaction conditions. The allene products can be used in acid catalyzed cyclization reactions to give trifluoromethylated indene products.Enzyme-responsive supramolecular peptide biomaterials have attracted growing interest for disease diagnostics and treatments. However, it remains unclear whether enzymes target the peptide assemblies or dissociated peptide monomers. To gain further insight into the degradation mechanism of supramolecular peptide amphiphile (PA) nanofibers, cathepsin B with both exopeptidase and endopeptidase activities was exploited here for degradation studies. Hydrolysis was found to occur directly on the PA nanofibers as only surface amino acid residues were cleaved. The number of cleaved residues and the degradation efficiency was observed to be negatively correlated with the internal viscosity of the PA nanofibers, quantified to be between 200-800 cP (liquid phase) using fluorescence lifetime imaging microscopy combined with an environmentally sensitive molecular rotor, BODIPY-C10. These findings enhance our understanding on the enzymatic degradation of supramolecular PA nanofibers and have important implications for the development of PA probes for the real-time monitoring of disease-related enzymes.