Muscular adaptation to physical exercise has previously been described as a repair process following tissue damage. Recently, evidence has been published to question this hypothesis. The purpose of this study was to investigate inflammatory processes in human skeletal muscle and epimysium after acute physical exercise with large eccentric components. Three groups of subjects ( n = 19) performed 45 min treadmill running at either 4 deg ( n = 5) or 8 deg ( n = 9) downhill or 4 deg uphill ( n = 5) and one group served as control ( n = 9). One biopsy was taken from each subject 48 h post exercise. Blood samples were taken up to 7 days post exercise. Compared to the control group, none of the markers of inflammation in muscle and epimysium samples was different in any exercised group. Only subjects in the Downhill groups experienced delayed onset of muscle soreness (DOMS) and increased serum creatine kinase activity (CK). The detected levels of immunohistochemical markers for T cells (CD3), granulocytes (CD11b), leukaemia inhibitory factor (LIF) and hypoxia-inducible factor 1Î² (HIF-1Î²) were greater in epimysium from exercised subjects with DOMS ratings >3 (0â10 scale) compared to exercised subjects without DOMS but not higher than controls. Eccentric physical exercise (downhill running) did not result in skeletal muscle inflammation 48 h post exercise, despite DOMS and increased CK. It is suggested that exercise can induce DOMS by activating inflammatory factors present in the epimysium before exercise. Repeated physical training may alter the content of inflammatory factors in the epimysium and thus reduce DOMS.
The purpose of this study is to determine the pyrolysis characteristics and gas product properties of palm oil wastes, to promote a general idea of converting the wastes to an energy source. The palm oil waste contains similar to50 wt % carbon, 7 wt % hydrogen, and a trace amount of ash. The low heat value (LHV) of these wastes is similar to20 MJ/kg. They are ideal energy sources for biofuel generation. Thermal analysis demonstrates that these wastes are easily decomposed, with most of their weight lost from 220 degreesC to 340 degreesC at slow heating rates. The pyrolysis process could be divided into four stages: moisture evaporation, hemicellulose decomposition, cellulose decomposition, and lignin degradation. The kinetic analysis showed that the reaction order for the pyrolysis of palm oil wastes and three model biomass components (hemicellulose, cellulose, and lignin) is 1. The activation energy of the palm oil wastes is similar to60 kJ/mol. The decomposition process is prolonged and the maximum mass loss rate is decreased when the heating rate is increased from 0.1 degreesC/min to 100 degreesC/min. Varying the particle size from 250 mum to > 2 mm has no significant influence on pyrolysis. The main gaseous products from the pyrolysis of palm oil waste are identified using thermogravimetric analysis-Fourier transform infrared (TGA-FTIR) spectroscopy, and, particularly, their real-time evolution characteristics are investigated. This fundamental study provides a basic insight of the palm oil waste pyrolysis, which can benefit our current work in developing an advanced thermal processes for high-yield biofuel production from palm oil waste.
The connections in many networks are not merely binary entities, either present or not, but have associated weights that record their strengths relative to one another. Recent studies of networks have, by and large, steered clear of such weighted networks, which are often perceived as being harder to analyze than their unweighted counterparts. Here we point out that weighted networks can in many cases be analyzed using a simple mapping from a weighted network to an unweighted multigraph, allowing us to apply standard techniques for unweighted graphs to weighted ones as well. We give a number of examples of the method, including an algorithm for detecting community structure in weighted networks and a simple proof of the maximum-flow-minimum-cut theorem.