Sequential thermal dissolution of two low-rank coals and characterization of their structures by high-performance liquid chromatography/time-of-flight mass spectrometry and gas chromatography/mass spectrometry.

RATIONALE: Gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography/time-of-flight mass spectrometry (HPLC/TOF-MS) were used to separate and reveal the molecular characteristics of organic matter in low-rank coals. METHODS: Six soluble portions (SPs) were obtained by sequential thermal dissolution (TD) of two low-rank coals in the order of cyclohexane, acetone and methanol solvents at 300°C. Organic matter with different molecular characteristics were enriched in eachTD extract, which was further separated and analyzed by GC/MS and HPLC/TOF-MS using an electrospray ionization source in positive mode to obtain a comprehensive understanding of the structural composition of coals. RESULTS: Low polarity compounds like alkanes and arenes have a better solubility in cyclohexane. Phorone has the highest relative abundance in the acetone SPs, and the main compounds detected in the methanol SPs are alcohols and phenols. According to the data from HPLC/TOF-MS, most of the oxygen atoms are in the form of carbonyl and alkoxy groups. The nitrogen-containing compounds in SPs are mainly saturated aliphatic amines and pyridines. The sulfur-containing compounds mainly exist in the form of thioalkanes and thiophenes. CONCLUSIONS: Non-destructive methods were used to obtain soluble matter from coals, and different chromatographic and mass spectrometric techniques were used to separate and analyze the organic matter in coals. Detailed molecular structural information was obtained for the efficient and clean utilization of low-rank coals.

Analysis of soluble components in coals and interpretations for the complex mass spectra.

RATIONALE: The deduction of useful information from the mass spectra of a complex mixture like coals remains difficult, which limits the clean and efficient utilization of coals. It is necessary to explore the data interpretation methods for mass spectra and visualize the analytical data of coals for industrial utilization such as feedstock selection. METHODS: Coal sample and methanol were mixed and heated to 310 °C and kept at that temperature for 2 h. The solvent was under supercritical state at 310 °C and the solubility for the solid mixture increased. Soluble products from thermal dissolution of two Chinese coals were analyzed by high-performance liquid chromatography/atmospheric pressure chemical ionization orbitrap mass spectrometry. RESULTS: The iso-abundance plot for molecules in coals was upgraded to display the distributions of isomers which are indicated as concentric circles or triangles with the same carbon number and value of double-bond equivalent. The concentration ratio was introduced from economics to describe the content inequality of organic species within the same class of coal molecules. CONCLUSIONS: Interpretation methods for mass spectra visualize and simplify the understanding of complex components in coals for industrial utilization. Coals with a high concentration ratio for a specific class should take priority as a feedstock for chemicals and receive more attention. Copyright © 2016 John Wiley & Sons, Ltd.

Sequential ultrasonic extraction of a Chinese coal and characterization of nitrogen-containing compounds in the extracts using high-performance liquid chromatography with mass spectrometry.

Dongming lignite was sequentially extracted with petroleum ether, carbon disulfide, methanol, acetone, and isometric carbon disulfide/acetone mixed solvent at room temperature to afford extracts 1-5, respectively. High-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry was used to separate and characterize heteroatomic species in the extracts at molecular level. Molecular mass of compounds in the extracts is mainly distributed from 300 to 800 u, and the relative abundance of compounds with molecular mass over 800 u in the carbon disulfide extract is 135 times of that in the petroleum ether extract. The acetone extract has the highest relative abundance for organonitrogen compounds. Double bond equivalence numbers of detected species indicate that most of the organonitrogen compounds contain N-heterocyclic aromatic rings, including pyridine, quinoline and pyrrole. Some organonitrogen isomers in Dongming lignite were separated and identified by high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry, and the corresponding structural information was proposed.

Atlanto-axial pedicle screw fixation through posterior approach for treatment of atlanto-axial joint instability / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the therapeutic effects of the atlantoaxial pedicle screw system fixation in treatment of atlantoaxial instability.</p><p><b>METHODS</b>From June 2003 to March 2010, 32 patients with atlantoaxial instability were treated by atlantoaxial pedicle screw system fixation, included 21 males and 11 females wiht an average age of 42.5 years old ranging from 28 to 66 years. Among them, 18 cases were odontoid process fractures, 7 were congenital dissociate odontoid process, 4 were Jefferson fracture combined with odontoid fracture, 3 were rheumatic arthritis causing atlantoaxial instability. All patients suffered from the atlantoaxial subluxation and atlantoaxial instability. The JOA score ranged from 4 to 14 (means 9.1 +/- 0.3) before operation. The patients had some image examination including the X-ray of cervical vertebrae (include of dynamic position film), spiral CT 3D reconstruction and/or MRI. The position of pedicle screw system implantation,the angle of pedicle screw system implantation and screw length were measured. Operating skull traction. Operation undewent general anesthesia, implanted the pedicle screw, reduction and bone fusion under direct vision. The bone was fixated between posterior arch of atlas and lamina of axis by the lateral combination bended to posterior.</p><p><b>RESULTS</b>One hundred and twenty-eight atlantoaxial pedicle screws were implanted in 32 patients. No patient had the injure of spinal cord, nerve root and vertebral artery. All patients were followed-up from 6 to 48 months (averaged 16 months). After operation, the JOA score ranged from 11 to 17 (averaged 15.9 +/- 0.2), improvement rate was 86.1%. The fracture of odontoid process were healing completely. All fusion bone were combinated. The internal fixation wasn't loosening and breaking.</p><p><b>CONCLUSION</b>The atlantoaxial pedicle screw system fixation was effective method to treat atlantoaxial instability. The method had many advantages, such as provide rigid and short segment fixation, safe and simple, high fusion rate. The method was worth in clinical application.</p>

Effect of IGF-1 on NO and PGE2 in rabbit articular chondrocytes induced by IL-1 / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of insulin-like growth factor (IGF-1) on the concentration of NO and PGE(2) in the supernatant of rabbit articular chondrocytes induced by IL-1, and to explore the mechanism of IGF-1 in the development of osteoarthritis (OA).@*METHODS@#The samples were divided into 7 groups: IL-1beta 10 microg/L group, IL-1beta 10 microg/L+IGF-1 1 microg/L group, IL-1beta 10 microg/L+IGF-1 10 microg/L group, IL-1beta 10 microg/L+IGF-1 50 microg/L group, IL-1beta 10 microg/L+IGF-1 100 microg/L group, IGF-1 50 microg/L group, and a blank control group. The chondrocytes from the articular cartilage of 2 month old rabbits were cultivated and identified, and then co-cultured in the second filial generation chondrocytes on plates with or without recombinant human IGF-1 or IL-1. The concentration of NO was detected by nitrate reductase kit, and that of PGE(2) by enzyme-linked immunosorbent assay (ELISA). The results were analyzed by statistical method.@*RESULTS@#The average value of NO and PGE(2) was (89.971+/-10.224) micromol/L and (22.028+/-8.731) micromol/L in the IL-1beta 10 microg/L group, and (12.404+/-8.809) micromol/L and (1.900+/-0.227) ng/L in the blank control group. The concentration of NO and PGE(2) in IL-1beta 10 microg/L group was significantly higher than that in the blank control group (P<0.05). At the same concentration of 10 microg/L, IGF-1 could dose-dependently decrease the increase of NO and PGE(2) concentration induced by IL-1beta in the chondrocytes supernatant in vitro, and the optimum concentration of IGF-1 was 50 microg/L.@*CONCLUSION@#IL-1 can significantly increase the concentration of NO and PGE(2), and IGF-1 can dose-dependently decrease the concentration of NO and PGE(2) in the chondrocytes supernatant in vitro. The optimum concentration of IGF-1 was 50 microg/L.

Culture of chondrocytes using nano-hydroxyapatite/collagen in vitro / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the value of the nano-hydroxyapatite/ collagen (nHAC) as a scaffold for cartilage tissue engineering.@*METHODS@#The normal cartilage from patients after total hip arthroplasty of osteoarthritis was selected, and then chondrocytes were digested, separated, and amplificate in vitro. The chondrocytes were seeded onto the nHAC scaffold and were cultured in a 3-dimensional environment for 5 and 10 days. The effects of the composite scaffold on the cell adhesion, proliferation, morphological changes, and synthesis of the extracellular matrix were observed by scanning electronic microscopy and immunohistochemistry.@*RESULTS@#The chondrocytes could adhere to the surface of the scaffolds, proliferate, and migrate into the scaffolds. They maintained round and could secrete extracellular matrix on the porous scaffold.@*CONCLUSION@#The nHAC can be used as the cartilage cell carrier.

Research Progress of Biodegradable Scaffolds in Constructing Tissue Engineering Cartilage / 中国生物工程杂志

Articular cartilage repair is limited. Current treatments for cartilage defect are less satisfactory, and rarely restore full function or return the tissue to its native normal state. The rise of tissue engineering holds great promise for the generation of functional cartilage tissue substitutes. The history of cartilage tissue engineering and highlights the applications and advantages of various kinds of scaffolds in cartilage tissue engineering, such as native scaffolds, synthesis scaffolds, composite scaffolds and nanometer scaffolds had been introduced. But native scaffolds have weak strength and immunogenicity insufficiency, synthesis scaffolds degrade quickly, whose degrading products have cytotoxicity,which need further improvement. The application of superficial decoration overcomes the disadvantage of some scaffolds to an extend. Composite scaffolds possess the advantages of several scaffolds, it points out the direction of future scaffolds research. The development of Nanometer technique endows newly-synthesis scaffolds with nano-grade, thus it has some advantages and give a new way for the development of tissue engineering. At the end, the problems of these scaffolds, their trend of development and perspective studies were discussed.