Construction of Macromolecules of Depolymerized Lignite.

Preparing ash-less coal and further converting it into chemicals is an efficient and promising means for lignite utilization. This work performed depolymerization of lignite to prepare ash-less coal (SDP) and separated it into the hexane-soluble fraction (HS), toluene-soluble fraction (TS), and tetrahydrofuran-soluble fraction (THFS). The structure of SDP and those of subfractions were characterized by elemental analysis, gel permeation chromatography, Fourier transform infrared spectroscopy, and synchronous fluorescence spectroscopy. The results show that SDP is a mixture of aromatic derivatives containing alkyl substituents and oxygen-containing functional groups. The number of condensed aromatic rings, the amount of oxygen-containing functional groups, and the molecular weight gradually increase as HS < TS < THFS. SDP was further analyzed by 1H-NMR and 13C-NMR to calculate its structural parameters. The macromolecule of THFS contains 15.8 total ring systems with 9.2 aromatic rings and 6.6 naphthenic rings. On average, each THFS molecule contains 6.1 alcohol hydroxyl groups, 3.9 phenol hydroxyl groups, 1.4 carboxyl groups, and 1.0 inactive oxygen-containing functional groups. The dominant reactions occurred during depolymerization are the breakage of ether linkages. The average THFS molecule consists of 3.3 structural units with aromatic nuclei (2.8 rings on average) linked with methylene, naphthene, and so forth.

The role of Cortistatin-14 in the gastrointestinal motility in mice.

BACKGROUND: This study aimed to investigate the functional roles of Cortistatin-14 (CST-14) in the gastrointestinal (GI) motility. METHODS: For in vivo study, mice were randomly divided into control, ip injected CST-14 (0.1, 0.5, 1, 5, 10mg/kg)+control group, icv injected CST-14 (5µg)+control group, dextran sulfate sodium-induced colitis group, CST-14+colitis group, castor oil-induced diarrhea group, CST-14+diarrhea group. We carried out these experiments by quantitative real-time PCR, GI transit, bead expulsion and fecal pellet output. For in vitro study, effects of CST-14 were investigated in the longitudinal and circular muscle contractions of jejum, ileum, and colon. RESULTS: In vivo, the expression of CST-14 mRNA was significantly decreased in the colon of colitis mice and CST-14 significantly inhibited GI transit rate in colitis mice, and delayed the emergence of liquid feces in castor oil-induced diarrhea mouse model. Additionally, ip injection of CST-14, but not icv injected, remarkably inhibited GI transit, bead expulsion and fecal pellet output in mice. In vitro assays, CST-14 (10-6M) could relax the rhythms of the longitudinal muscles and circular muscles of the jejunum, ileum and colon of mice. The further study indicated that the roles of CST-14 in mouse GI motility were significantly reversed by c-SOM (sstr1-5 antagonist), especially sstr2 and sstr3 and propranolol (ß-adrenoceptor blocker), suggesting that somatostatin system and noradrenaline system were involved in the inhibiting effects of CST-14 in GI. CONCLUSION: Such inhibiting effects imply that CST-14 system in gastrointestinal motility might be a new target for treatment of GI tract disorder.

[Fluorescence spectroscopy characterization of asphaltene liquefied from coal and study of its association structure].

Structure and association of asphaltenes from coal direct hydroliquefaction were studied by fluorescence spectrometry and UV-Vis absorption spectrometry in this paper. The results indicate that asphaltene is aromatic mixtures mainly containing naphthalene nucleus and shows strong fluorescent characteristic. The forming of exciplex between asphaltene and solvent results in the red shift of fluorescence peak and fluorescence quenching of asphaltene that increases with the polarity and electron acceptability. The self-aggregation of asphaltene is formed by non-covalent bond interaction, so that the asphaltene liquefied at higher temperture that shows high aromaticity has stronger association than that liquefied at lower temperature. Aggregation of asphaltene has been found to be a gradual process, in which there is no critical aggregation constant observed, and the inflection point of the plot of apparent fluorescence intensity as a function of asphaltene concentration varies with the excitation wavelength.