Recent advances in computer vision (CV) and natural language processing have been driven by exploiting big data on practical applications. However, these research fields are still limited by the sheer volume, versatility, and diversity of the available datasets. CV tasks, such as image captioning, which has primarily been carried out on natural images, still struggle to produce accurate and meaningful captions on sketched images often included in scientific and technical documents.
View Article and Find Full Text PDFAvian paramyxovirus 1 (APMV-1), also known as Newcastle disease virus (NDV), causes severe and economically important disease in poultry around the globe. Although a limited amount of APMV-1 strains in urban areas have been characterized, the role of the urban wild bird population as an APMV-1 reservoir is unclear. Because urban birds may have an important role for long-term circulation of the virus, fecal and swab samples were collected by community scientists from wild birds in New York City (NYC), New York, United States.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2017
Mycobacterium tuberculosis (Mtb) DprE1, an essential isomerase for the biosynthesis of the mycobacterial cell wall, is a validated target for tuberculosis (TB) drug development. Here we report the X-ray crystal structures of DprE1 and the DprE1 resistant mutant (Y314C) in complexes with TCA1 derivatives to elucidate the molecular basis of their inhibitory activities and an unconventional resistance mechanism, which enabled us to optimize the potency of the analogs. The selected lead compound showed excellent in vitro and in vivo activities, and low risk of toxicity profile except for the inhibition of CYP2C9.
View Article and Find Full Text PDFA library of benzimidazole-substituted potassium organotrifluoroborates was prepared via the condensation of various potassium formyl-substituted aryl- and heteroaryltrifluoroborates with aromatic 1,2-diamines under oxidative conditions. The efficient Suzuki-Miyaura cross-coupling of products thus formed to various aryl and heteroaryl bromides was achieved in good yields. The method allows the facile preparation of benzimidazole-containing triaromatic products in two steps from simple potassium formyl substituted aryl- or heteroaryltrifluoroborates.
View Article and Find Full Text PDFA protected cyclitol aglycon was tethered to an (N-arylsulfonyl)glucosamine donor by a methylene linker; the exclusively alpha-selective intramolecular glycosylation reaction was then initiated by electrophilic activation of the thioglycoside donor portion. Further transformations of the glycosylation product to give the M. tuberculosis detoxifier mycothiol and its oxidized congener, the disulfide mycothione, are detailed.
View Article and Find Full Text PDFThe potent O-GlcNAcase (OGA) inhibitor GlcNAc-thiazoline has been modified by buffer- or acylation-induced imine-to-enamine conversion and then electrophile or radical addition (Xn = D3, F, N3, OH, SMe, COCF3, CF3). Several functionalized GlcNAc-thiazolines show highly selective inhibition of OGA vs human hexosaminidase and thus have promise as tools for targeted investigations of OGA, an enzyme linked to diabetes and neurodegeneration. A new radical addition/fragmentation reaction of the N-(trifluoroacetyl)enamine has been discovered.
View Article and Find Full Text PDFThe O,O-dibenzyl-S-glycosyl phosphothioite derived from 3,4,6-tri-O-acetyl-2-acetamido-2-deoxy-1-thio-alpha-D-glucopyranose rearranges under the influence of triethylborane and air to provide the corresponding 1-C-pyranosyl-O,O-dibenzylphosphonothioate, a new type of carbohydrate derivative. The isomeric beta phosphothioite is compared, and evidence of a radical chain mechanism for the Pudovik rearrangement is presented.
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