Jing-Li Zhang

Phylogenetic relationship of China Dendrobium species based on the sequence of the internal transcribed spacer of ribosomal DNA

The genetic relationship of 36 Dendrobium species in China was determined based on sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA. Aligned sequences of the complete ITS region obtained from the 36 Dendrobium species and 2 outgroup species (Epigeneium amplum and Epigeneium nakaharaei) by using PCR amplification and direct DNA sequencing. The nrDNA ITS1 of Dendrobium was 225–234 bp and ITS2 was 239–248 bp. Phylogenetic tree was constructed, and seven main clusters were generated among the 36 Dendrobium species. From the results, D. moulmeinense was not grouped in the classification of Dendrobium and E. amplum and E. nakaharaei were shown to be divergent from Dendrobium species. The phylogenetic relationships revealed by ITS DNA analysis partially supported previously published morphological data.

Tetraphenylethene-containing supramolecular hyperbranched polymers: aggregation-induced emission by supramolecular polymerization in aqueous solution

Supramolecular hyperbranched polymers have been successfully constructed by using host-enhanced π–π interactions between CB[8] and a naphthyl-substituted tetraphenylethene derivative, which exhibit a strong fluorescence in aqueous solution due to aggregation-induced emission.

Self-assembled reduced graphene hydrogels by facile chemical reduction using acetaldehyde oxime for electrode materials in supercapacitors

Self-assembled three-dimensional (3D) reduced graphene hydrogels (RGHs) were fabricated by the facile chemical reduction of a graphene oxide (GO) dispersion with ammonia using acetaldehyde oxime as reducing and doping agent. The chemical reduction of GO was confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The hierarchical porosity and structures of the resulting RGHs can be demonstrated by field emission scanning electron microscopy (FESEM) and N2 sorption experiments. Benefiting from the developed porosity with micro-meso hierarchical pore texture, the specific capacitance of RGHs exhibited high specific capacitances of 230.4, 155.3, 234.2, 155.1 and 191.8 F g−1 at 0.3 A g−1 for RGHs-1, RGHs-2, RGHs-5, RGHs-10 and RGHs-15 in 6 M KOH electrolyte, respectively. More importantly, the RGHs maintained high capacitances of 167.1, 110.4, 142.3, 106.9 and 142.3 F g−1 (the retention rates are 72.5, 71.1, 60.8, 68.9 and 74.2% for RGHs-1, RGHs-2, RGHs-5, RGHs-10 and RGHs-15) at a very high current density of 20 A g−1, indicating good electrochemical stability and a high degree of reversibility in the repetitive charge/discharge cycling test.

Binuclear alkynylplatinum( ii ) terpyridine complexes with flexible bridges behave as organogelators for several organic solvents

New binuclear alkynylplatinum(II) terpyridyl complexes with flexible bridges have been synthesized and characterized by 1H NMR, mass spectra and elemental analysis. These compounds can gelate a variety of organic solvents via multiple intermolecular interactions such as metal–metal (Pt⋯Pt) and π–π stacking interactions, hydrogen bonding interactions, and van der Waals forces, which were confirmed by ultraviolet-visible (UV-vis) absorption spectroscopy, rheological studies, temperature-dependent 1H NMR spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Moreover, compound 1b with a longer flexible bridge (–O(CH2)6O–) exhibited higher gelation ability than that of compound 1a with a shorter flexible bridge (–O (CH2)4O–). A scanning electron microscopy (SEM) investigation of the xerogels from different organic solvents gave a visual image showing that fibrillar aggregates are entangled in three-dimensional network structures.

Enhancement of polysaccharides accumulation in Dendrobium officinale by exogenously applied methyl jasmonate

The accumulation of polysaccharides, activities of sucrose metabolism enzymes, and the expression of sucrose biosynthetic genes in Dendrobium officinale were significantly affected by exogenous methyl jasmonate (MeJA). Application of MeJA increased the content of polysaccharides and the highest polysaccharide production occurred in the samples treated with 200 μM MeJa. The MeJA application influenced polysaccharide biosynthesis rather than degradation because the activities of sucrose metabolism enzymes and the expressions of sucrose biosynthetic genes were upregulated by MeJA. Interestingly, low MeJA concentrations promoted accumulation of Dendrobium polysaccharides, while high MeJA amounts played an inhibitory role. The content of major constituent of polysaccharides, glucose and mannose, also increased after MeJa treatment.

Three-Dimensional Reduced Graphene Hydrogels Using Various Carbohydrates for High Performance Supercapacitors

In present work, three-dimensional (3D) reduced graphene hydrogels (RGHs) are prepared through an efficient and facile strategy by employing three types of carbohydrates (glucose, fructose and sucrose) as reducing agents in aqueous solution of graphene oxide (GO) with ammonia. The formation of RGHs could be confirmed by X-ray powder diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The structures and porosity were characterized by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and N2 sorption experiments. Benefiting from the abundant porous architectures as fast ionic channels for electrochemical energy storage, the prepared RGHs exhibited a high specific capacitance up to 153.5, 145.0 and 150.3 F g−1 at 0.3 A g−1 for FRGHs (fructose), GRGHs (glucose) and SRGHs (sucrose), which can be maintained for 61.4, 61.5 and 46.9% as the discharging current density was increased up to 20 A g−1. Moreover, it also showed that the electrode based on RGHs has good electrochemical stability and high degree of reversibility in the charge/discharge cycling test.