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Detailed and unambiguous characterization of the surface structure of detonation nanodiamond (DND) particles remains one of the most challenging tasks for the preparation of chemically functionalized nanodiamonds. In the present paper, a combination of FTIR, NMR, and XPS was used to characterize DND particles that were treated in a reduction reaction that results in the enrichment of hydroxyl and hydroxymethyl functional groups. FTIR spectra and quantum-chemistry modeling demonstrated that the vacuum treatment of the sample, with the purpose of the removing adsorbed water and other volatile contaminates, is mandatory to obtain the correct data on the nature and relative content of the −OH surface groups on DND. 13C and 1H NMR spectra show signals from the diamond core, hydroxyl, hydrocarbon groups, and moisture on the diamond surface. NMR data were taken for as-prepared DNDs, as well as those that were dried under vacuum conditions of 10–4 Torr, in order to distinguish between the NMR signal contributions due to moisture and other hydrogen-containing groups.

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The catalytic properties of sp 3 -hybridized ultra-dispersed diamond and sp 2 -hybridized onion-like carbon in the oxidative dehydrogenation of ethylbenzene to styrene were investigated, highlighting the structure sensitivity of the reaction. The sp 3 -carbon led initially to C-C cleavage and benzene formation, while a switchover of the main reaction pathway into the styrene formation occurred with time on stream due to the formation of surface sp 2 carbon, required for the selective styrene formation. This was confirmed by the behavior and the high stable styrene selectivity shown by onion-like carbons. High temperature oxygen pre-treatment created catalytically active species at the sp 2 carbon surface, confirming that a high thermal stability carbon-oxygen complex was the active surface site for forming styrene.

R-loop is the structure co-transcriptionally formed between nascent RNA transcript and DNA template, leaving the non-transcribed DNA strand unpaired. This structure can be involved in the hyper-mutation and dsDNA breaks in mammalian immunoglobulin (Ig) genes, oncogenes and neurodegenerative disease related genes. R-loops have not been studied at the genome scale yet. To identify the R-loops, we developed a computational algorithm and mapped R-loop forming sequences (RLFS) onto 66 803 sequences defined by UCSC as ‘known’ genes. We found that ∼59% of these transcribed sequences contain at least one RLFS. We created R-loopDB (http://rloop.bii.a-star.edu.sg/), the database that collects all RLFS identified within over half of the human genes and links to the UCSC Genome Browser for information integration and visualisation across a variety of bioinformatics sources. We found that many oncogenes and tumour suppressors (e.g. Tp53, BRCA1, BRCA2, Kras and Ptprd) and neurodegenerative diseases related genes (e.g. ATM, Park2, Ptprd and GLDC) could be prone to significant R-loop formation. Our findings suggest that R-loops provide a novel level of RNA–DNA interactome complexity, playing key roles in gene expression controls, mutagenesis, recombination process, chromosomal rearrangement, alternative splicing, DNA-editing and epigenetic modifications. RLFSs could be used as a novel source of prospective therapeutic targets.

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