A competition between N---O and C---O through space interactions in the crystal structures of 3,3'-dinitro-2,2'-bipyridine N-oxides and N,N'-dioxides

The crystal structures of a series of 3,3’-dinitro-2,2’-bipyridine N-oxides and N,N’-dioxides consistently show 1,5 interactions between nitro oxygen atoms and aromatic carbon atoms ((ON)O---C: 2.623(2)-2.839(2) Å) while there are also 1,6 interactions between N-oxide oxygen atoms and nitro nitrogen atoms in most cases (O---N(O2): 2.737(2)-2.874(3) Å). The O---C interactions appears to be a common feature in ortho-nitro-biphenyl systems, and there is some evidence that the effect is cooperative when there are ortho nitro groups on both rings. The O---N interactions are considerably longer than the corresponding 1,5 N---O interaction measured here in 8-nitroquinoline-1-oxide (O---N(O2): 2.5418(17) Å), which in turn is longer than the corresponding N---O interaction in the corresponding 8-diazonium-1-oxide analogue

1,6-Interactions between dimethylamino and aldehyde groups in two biphenyl derivatives

The title compounds, 2-(dimethylamino)biphenyl-2'-carboxaldehyde, C15H15NO, and 2-(dimethylamino)biphenyl-2',6'-dicarboxaldehyde, C16H15NO2, show similar 1,6-interactions [N...C=O 2.929 (3) to 3.029 (3) Å] between the dimethylamino and aldehyde groups located in the ortho positions of the two rings, which lie at 58.1 (1)-62.4 (1)° to each other

Structural studies of peri-interactions and bond formation between electron-rich atomic centres and N-phenylcarboxamides or nitroalkenyl groups

Structural studies of peri-interactions with dimethylamino groups in naphthalene systems indicate that the N-phenylcarboxamide group has a through-space electron attracting power closer to that of a carboxylic ester than a N,N-dialkylcarboxamide, while 2-nitroalkenyl groups have a lower through-space electron attracting power. However, addition of a benzoyl group to the 2-position of the nitroethenyl group leads to cyclisation to give a zwitterion, in which the carbanion is stabilised by full conjugation with the nitro group and partial conjugation with the carbonyl group. An interesting case where a steric interaction overrides an electrophile/nucleophile attraction is also described. The limitations to the interpretation of short contact distances from crystallographic measurements are discussed

AI for the Public Sector: Opportunities and challenges of cross-sector collaboration

Public sector organisations are increasingly interested in using data science and artificial intelligence capabilities to deliver policy and generate efficiencies in high uncertainty environments. The long-term success of data science and AI in the public sector relies on effectively embedding it into delivery solutions for policy implementation. However, governments cannot do this integration of AI into public service delivery on their own. The UK Government Industrial Strategy is clear that delivering on the AI grand challenge requires collaboration between universities and public and private sectors. This cross-sectoral collaborative approach is the norm in applied AI centres of excellence around the world. Despite their popularity, cross-sector collaborations entail serious management challenges that hinder their success. In this article we discuss the opportunities and challenges from AI for public sector. Finally, we propose a series of strategies to successfully manage these cross-sectoral collaborations

Gene expression in the rat brain: High similarity but unique differences between frontomedial-, temporal- and occipital cortex

<p>Abstract</p> <p>Background</p> <p>The six-layered neocortex of the mammalian brain may appear largely homologous, but is in reality a modular structure of anatomically and functionally distinct areas. However, global gene expression seems to be almost identical across the cerebral cortex and only a few genes have so far been reported to show regional enrichment in specific cortical areas.</p> <p>Results</p> <p>In the present study on adult rat brain, we have corroborated the strikingly similar gene expression among cortical areas. However, differential expression analysis has allowed for the identification of 30, 24 and 11 genes enriched in frontomedial -, temporal- or occipital cortex, respectively. A large proportion of these 65 genes appear to be involved in signal transduction, including the ion channel <it>Fxyd6</it>, the neuropeptide <it>Grp </it>and the nuclear receptor <it>Rorb</it>. We also find that the majority of these genes display increased expression levels around birth and show distinct preferences for certain cortical layers and cell types in rodents.</p> <p>Conclusions</p> <p>Since specific patterns of expression often are linked to equally specialised biological functions, we propose that these cortex sub-region enriched genes are important for proper functioning of the cortical regions in question.</p

Why Do Hubs in the Yeast Protein Interaction Network Tend To Be Essential: Reexamining the Connection between the Network Topology and Essentiality

The centrality-lethality rule, which notes that high-degree nodes in a protein interaction network tend to correspond to proteins that are essential, suggests that the topological prominence of a protein in a protein interaction network may be a good predictor of its biological importance. Even though the correlation between degree and essentiality was confirmed by many independent studies, the reason for this correlation remains illusive. Several hypotheses about putative connections between essentiality of hubs and the topology of protein–protein interaction networks have been proposed, but as we demonstrate, these explanations are not supported by the properties of protein interaction networks. To identify the main topological determinant of essentiality and to provide a biological explanation for the connection between the network topology and essentiality, we performed a rigorous analysis of six variants of the genomewide protein interaction network for Saccharomyces cerevisiae obtained using different techniques. We demonstrated that the majority of hubs are essential due to their involvement in Essential Complex Biological Modules, a group of densely connected proteins with shared biological function that are enriched in essential proteins. Moreover, we rejected two previously proposed explanations for the centrality-lethality rule, one relating the essentiality of hubs to their role in the overall network connectivity and another relying on the recently published essential protein interactions model

The Regulation of Sulfur Metabolism in Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) has evolved into a highly successful human pathogen. It deftly subverts the bactericidal mechanisms of alveolar macrophages, ultimately inducing granuloma formation and establishing long-term residence in the host. These hallmarks of Mtb infection are facilitated by the metabolic adaptation of the pathogen to its surrounding environment and the biosynthesis of molecules that mediate its interactions with host immune cells. The sulfate assimilation pathway of Mtb produces a number of sulfur-containing metabolites with important contributions to pathogenesis and survival. This pathway is regulated by diverse environmental cues and regulatory proteins that mediate sulfur transactions in the cell. Here, we discuss the transcriptional and biochemical mechanisms of sulfur metabolism regulation in Mtb and potential small molecule regulators of the sulfate assimilation pathway that are collectively poised to aid this intracellular pathogen in its expert manipulation of the host. From this global analysis, we have identified a subset of sulfur-metabolizing enzymes that are sensitive to multiple regulatory cues and may be strong candidates for therapeutic intervention