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In this study, we prepared Q-carbon by adjusting the sp3 content in diamond-like carbon (DLC) films and the laser energy density of pulsed laser annealing (PLA). The amorphous DLC films were fabricated on sapphire Al2O3(0001) substrates using a pulsed laser deposition technique with a KrF excimer laser (λ = 248 nm). The sp3 content in the films varied between 20% and 42% by changing the laser energy density. Subsequently, PLA was performed on the DLC films by using the KrF excimer laser with energy densities between 0.5 and 1.2 J/cm2. The prepared films were characterized using scanning electron microscopy, Raman spectroscopy, and magnetization measurements. Consequently, for the combination of 20% sp3 content and laser density of 1.0 J/cm2, as well as 42% sp3 and 0.5 J/cm2, the films showed the characteristic features of Q-carbon: filamentary nanostructures, the presence of a T band in the Raman spectrum, room-temperature ferromagnetic behavior, and ∼80% sp3 content. The results indicate that Q-carbon can be obtained by using a proper combination of sp3 content in DLC films and an appropriate PLA energy density. This study provides important guidance for establishing a preparation method for Q-carbon.

The chemical synthesis of the highly branched core oligosaccharides of lipooligosaccharides (LOSs) found in Campylobacter jejuni, which causes Guillain-Barre syndrome by a preceding infection, is described. The target LOS mimics, consisting of eight or nine monosaccharides, were classified into three groups as key building blocks: ganglioside-core tetra-/pentasaccharides (GM1-/GD1a-like), l-glycero-d-manno-heptose-containing trisaccharides, and 3-deoxy-d-manno-2-octulosonic acid (KDO) residues. These synthetic fragments were obtained from commercially available monosaccharides. Less obtainable l-glycero-d-manno-heptose and KDO residues, as key components of the LOSs, were synthesized from p-methoxyphenyl d-mannoside and di-O-isopropylidene-protected d-mannose, respectively. The synthesis of α-KDO glycoside, as one of the most difficult stereocontrolled glycosidic constructions, was achieved by treating a 2,3-ene derivative of KDO with phenylselenyl trifluoromethanesulfonate as a suitable α-directing reagent. All synthetic blocks were constructed through a convergent synthetic route, which resulted in the first synthesis of structurally challenging LOS core glycans containing ganglioside GM1 and GD1a-core sequences.